[PATCH 00/25] btrfs: migrate the block group code

[PATCH 00/25] btrfs: migrate the block group code

[Josef Bacik]

This is the series to migrate the block group code out of extent-tree.c.  This
is a much larger series than the previous two series because things were much
more intertwined than block_rsv's and space_info.  There is one code change
patch in this series, it is

btrfs: make caching_thread use btrfs_find_next_key

This is so I didn't have to copy the simple helper from extent-tree.c into
block-group.c as well.  It's straightforward, but warrants a close look.

The rest is purely moving code around, no code changes at all.  I temporarily
export some functions at different points and then clean it all up at the end.

This patchset brings extent-tree.c down to ~5500 loc.  Thanks,

Josef

[PATCH 01/25] btrfs: move btrfs_add_free_space out of a header file

[Josef Bacik]

This is prep work for moving block_group_cache around.  Having this in
the header file makes the header file include need to be in a certain
order, which is awkward, so just move it into free-space-cache.c and
then we can re-arrange later.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/free-space-cache.c |  8 ++++++++
 fs/btrfs/free-space-cache.h | 10 ++--------
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 062be9dde4c6..92cb06dd94d3 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2376,6 +2376,14 @@ int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
 	return ret;
 }
 
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+			 u64 bytenr, u64 size)
+{
+	return __btrfs_add_free_space(block_group->fs_info,
+				      block_group->free_space_ctl,
+				      bytenr, size);
+}
+
 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
 			    u64 offset, u64 bytes)
 {
diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h
index 8760acb55ffd..2205a4113ef3 100644
--- a/fs/btrfs/free-space-cache.h
+++ b/fs/btrfs/free-space-cache.h
@@ -73,14 +73,8 @@ void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group);
 int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
 			   struct btrfs_free_space_ctl *ctl,
 			   u64 bytenr, u64 size);
-static inline int
-btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
-		     u64 bytenr, u64 size)
-{
-	return __btrfs_add_free_space(block_group->fs_info,
-				      block_group->free_space_ctl,
-				      bytenr, size);
-}
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+			 u64 bytenr, u64 size);
 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
 			    u64 bytenr, u64 size);
 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl);
-- 
2.14.3

[PATCH 02/25] btrfs: move basic block_group definitions to their own header

[Josef Bacik]

This is prep work for moving all of the block group cache code into its
own file.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.h                 | 156 +++++++++++++++++++++++++++++++++
 fs/btrfs/ctree.h                       | 148 +------------------------------
 fs/btrfs/disk-io.c                     |   1 +
 fs/btrfs/extent-tree.c                 |   1 +
 fs/btrfs/free-space-cache.c            |   1 +
 fs/btrfs/free-space-tree.c             |   1 +
 fs/btrfs/free-space-tree.h             |   2 +
 fs/btrfs/inode.c                       |   1 +
 fs/btrfs/ioctl.c                       |   1 +
 fs/btrfs/qgroup.c                      |   2 +-
 fs/btrfs/reada.c                       |   1 +
 fs/btrfs/relocation.c                  |   1 +
 fs/btrfs/scrub.c                       |   1 +
 fs/btrfs/space-info.c                  |   1 +
 fs/btrfs/super.c                       |   1 +
 fs/btrfs/sysfs.c                       |   1 +
 fs/btrfs/tests/btrfs-tests.c           |   1 +
 fs/btrfs/tests/free-space-tests.c      |   1 +
 fs/btrfs/tests/free-space-tree-tests.c |   1 +
 fs/btrfs/transaction.c                 |   1 +
 fs/btrfs/volumes.c                     |   1 +
 21 files changed, 177 insertions(+), 148 deletions(-)
 create mode 100644 fs/btrfs/block-group.h

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
new file mode 100644
index 000000000000..f3f99787af86
--- /dev/null
+++ b/fs/btrfs/block-group.h
@@ -0,0 +1,156 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Facebook.  All rights reserved.
+ */
+
+#ifndef BTRFS_BLOCK_GROUP_H
+#define BTRFS_BLOCK_GROUP_H
+
+enum btrfs_disk_cache_state {
+	BTRFS_DC_WRITTEN,
+	BTRFS_DC_ERROR,
+	BTRFS_DC_CLEAR,
+	BTRFS_DC_SETUP,
+};
+
+struct btrfs_caching_control {
+	struct list_head list;
+	struct mutex mutex;
+	wait_queue_head_t wait;
+	struct btrfs_work work;
+	struct btrfs_block_group_cache *block_group;
+	u64 progress;
+	refcount_t count;
+};
+
+/* Once caching_thread() finds this much free space, it will wake up waiters. */
+#define CACHING_CTL_WAKE_UP SZ_2M
+
+struct btrfs_block_group_cache {
+	struct btrfs_key key;
+	struct btrfs_block_group_item item;
+	struct btrfs_fs_info *fs_info;
+	struct inode *inode;
+	spinlock_t lock;
+	u64 pinned;
+	u64 reserved;
+	u64 delalloc_bytes;
+	u64 bytes_super;
+	u64 flags;
+	u64 cache_generation;
+
+	/*
+	 * If the free space extent count exceeds this number, convert the block
+	 * group to bitmaps.
+	 */
+	u32 bitmap_high_thresh;
+
+	/*
+	 * If the free space extent count drops below this number, convert the
+	 * block group back to extents.
+	 */
+	u32 bitmap_low_thresh;
+
+	/*
+	 * It is just used for the delayed data space allocation because
+	 * only the data space allocation and the relative metadata update
+	 * can be done cross the transaction.
+	 */
+	struct rw_semaphore data_rwsem;
+
+	/* for raid56, this is a full stripe, without parity */
+	unsigned long full_stripe_len;
+
+	unsigned int ro;
+	unsigned int iref:1;
+	unsigned int has_caching_ctl:1;
+	unsigned int removed:1;
+
+	int disk_cache_state;
+
+	/* cache tracking stuff */
+	int cached;
+	struct btrfs_caching_control *caching_ctl;
+	u64 last_byte_to_unpin;
+
+	struct btrfs_space_info *space_info;
+
+	/* free space cache stuff */
+	struct btrfs_free_space_ctl *free_space_ctl;
+
+	/* block group cache stuff */
+	struct rb_node cache_node;
+
+	/* for block groups in the same raid type */
+	struct list_head list;
+
+	/* usage count */
+	atomic_t count;
+
+	/* List of struct btrfs_free_clusters for this block group.
+	 * Today it will only have one thing on it, but that may change
+	 */
+	struct list_head cluster_list;
+
+	/* For delayed block group creation or deletion of empty block groups */
+	struct list_head bg_list;
+
+	/* For read-only block groups */
+	struct list_head ro_list;
+
+	atomic_t trimming;
+
+	/* For dirty block groups */
+	struct list_head dirty_list;
+	struct list_head io_list;
+
+	struct btrfs_io_ctl io_ctl;
+
+	/*
+	 * Incremented when doing extent allocations and holding a read lock
+	 * on the space_info's groups_sem semaphore.
+	 * Decremented when an ordered extent that represents an IO against this
+	 * block group's range is created (after it's added to its inode's
+	 * root's list of ordered extents) or immediately after the allocation
+	 * if it's a metadata extent or fallocate extent (for these cases we
+	 * don't create ordered extents).
+	 */
+	atomic_t reservations;
+
+	/*
+	 * Incremented while holding the spinlock *lock* by a task checking if
+	 * it can perform a nocow write (incremented if the value for the *ro*
+	 * field is 0). Decremented by such tasks once they create an ordered
+	 * extent or before that if some error happens before reaching that step.
+	 * This is to prevent races between block group relocation and nocow
+	 * writes through direct IO.
+	 */
+	atomic_t nocow_writers;
+
+	/* Lock for free space tree operations. */
+	struct mutex free_space_lock;
+
+	/*
+	 * Does the block group need to be added to the free space tree?
+	 * Protected by free_space_lock.
+	 */
+	int needs_free_space;
+
+	/* Record locked full stripes for RAID5/6 block group */
+	struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
+};
+
+#ifdef CONFIG_BTRFS_DEBUG
+static inline int
+btrfs_should_fragment_free_space(struct btrfs_block_group_cache *block_group)
+{
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
+
+	return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
+		block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
+	       (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
+		block_group->flags &  BTRFS_BLOCK_GROUP_DATA);
+}
+#endif
+
+#endif /* BTRFS_BLOCK_GROUP_H */
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 73e28d9c14bd..8a904115c553 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -39,6 +39,7 @@ struct btrfs_transaction;
 struct btrfs_pending_snapshot;
 struct btrfs_delayed_ref_root;
 struct btrfs_space_info;
+struct btrfs_block_group_cache;
 extern struct kmem_cache *btrfs_trans_handle_cachep;
 extern struct kmem_cache *btrfs_bit_radix_cachep;
 extern struct kmem_cache *btrfs_path_cachep;
@@ -431,26 +432,6 @@ enum btrfs_caching_type {
 	BTRFS_CACHE_ERROR,
 };
 
-enum btrfs_disk_cache_state {
-	BTRFS_DC_WRITTEN,
-	BTRFS_DC_ERROR,
-	BTRFS_DC_CLEAR,
-	BTRFS_DC_SETUP,
-};
-
-struct btrfs_caching_control {
-	struct list_head list;
-	struct mutex mutex;
-	wait_queue_head_t wait;
-	struct btrfs_work work;
-	struct btrfs_block_group_cache *block_group;
-	u64 progress;
-	refcount_t count;
-};
-
-/* Once caching_thread() finds this much free space, it will wake up waiters. */
-#define CACHING_CTL_WAKE_UP SZ_2M
-
 struct btrfs_io_ctl {
 	void *cur, *orig;
 	struct page *page;
@@ -473,120 +454,6 @@ struct btrfs_full_stripe_locks_tree {
 	struct mutex lock;
 };
 
-struct btrfs_block_group_cache {
-	struct btrfs_key key;
-	struct btrfs_block_group_item item;
-	struct btrfs_fs_info *fs_info;
-	struct inode *inode;
-	spinlock_t lock;
-	u64 pinned;
-	u64 reserved;
-	u64 delalloc_bytes;
-	u64 bytes_super;
-	u64 flags;
-	u64 cache_generation;
-
-	/*
-	 * If the free space extent count exceeds this number, convert the block
-	 * group to bitmaps.
-	 */
-	u32 bitmap_high_thresh;
-
-	/*
-	 * If the free space extent count drops below this number, convert the
-	 * block group back to extents.
-	 */
-	u32 bitmap_low_thresh;
-
-	/*
-	 * It is just used for the delayed data space allocation because
-	 * only the data space allocation and the relative metadata update
-	 * can be done cross the transaction.
-	 */
-	struct rw_semaphore data_rwsem;
-
-	/* for raid56, this is a full stripe, without parity */
-	unsigned long full_stripe_len;
-
-	unsigned int ro;
-	unsigned int iref:1;
-	unsigned int has_caching_ctl:1;
-	unsigned int removed:1;
-
-	int disk_cache_state;
-
-	/* cache tracking stuff */
-	int cached;
-	struct btrfs_caching_control *caching_ctl;
-	u64 last_byte_to_unpin;
-
-	struct btrfs_space_info *space_info;
-
-	/* free space cache stuff */
-	struct btrfs_free_space_ctl *free_space_ctl;
-
-	/* block group cache stuff */
-	struct rb_node cache_node;
-
-	/* for block groups in the same raid type */
-	struct list_head list;
-
-	/* usage count */
-	atomic_t count;
-
-	/* List of struct btrfs_free_clusters for this block group.
-	 * Today it will only have one thing on it, but that may change
-	 */
-	struct list_head cluster_list;
-
-	/* For delayed block group creation or deletion of empty block groups */
-	struct list_head bg_list;
-
-	/* For read-only block groups */
-	struct list_head ro_list;
-
-	atomic_t trimming;
-
-	/* For dirty block groups */
-	struct list_head dirty_list;
-	struct list_head io_list;
-
-	struct btrfs_io_ctl io_ctl;
-
-	/*
-	 * Incremented when doing extent allocations and holding a read lock
-	 * on the space_info's groups_sem semaphore.
-	 * Decremented when an ordered extent that represents an IO against this
-	 * block group's range is created (after it's added to its inode's
-	 * root's list of ordered extents) or immediately after the allocation
-	 * if it's a metadata extent or fallocate extent (for these cases we
-	 * don't create ordered extents).
-	 */
-	atomic_t reservations;
-
-	/*
-	 * Incremented while holding the spinlock *lock* by a task checking if
-	 * it can perform a nocow write (incremented if the value for the *ro*
-	 * field is 0). Decremented by such tasks once they create an ordered
-	 * extent or before that if some error happens before reaching that step.
-	 * This is to prevent races between block group relocation and nocow
-	 * writes through direct IO.
-	 */
-	atomic_t nocow_writers;
-
-	/* Lock for free space tree operations. */
-	struct mutex free_space_lock;
-
-	/*
-	 * Does the block group need to be added to the free space tree?
-	 * Protected by free_space_lock.
-	 */
-	int needs_free_space;
-
-	/* Record locked full stripes for RAID5/6 block group */
-	struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
-};
-
 /* delayed seq elem */
 struct seq_list {
 	struct list_head list;
@@ -1364,19 +1231,6 @@ static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
 	btrfs_clear_opt(fs_info->mount_opt, opt);			\
 }
 
-#ifdef CONFIG_BTRFS_DEBUG
-static inline int
-btrfs_should_fragment_free_space(struct btrfs_block_group_cache *block_group)
-{
-	struct btrfs_fs_info *fs_info = block_group->fs_info;
-
-	return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
-		block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
-	       (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
-		block_group->flags &  BTRFS_BLOCK_GROUP_DATA);
-}
-#endif
-
 /*
  * Requests for changes that need to be done during transaction commit.
  *
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 874913eaea8c..15b4e3221e7f 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -40,6 +40,7 @@
 #include "compression.h"
 #include "tree-checker.h"
 #include "ref-verify.h"
+#include "block-group.h"
 
 #define BTRFS_SUPER_FLAG_SUPP	(BTRFS_HEADER_FLAG_WRITTEN |\
 				 BTRFS_HEADER_FLAG_RELOC |\
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a0115e019ee8..aeb8daf2a640 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -31,6 +31,7 @@
 #include "space-info.h"
 #include "block-rsv.h"
 #include "delalloc-space.h"
+#include "block-group.h"
 
 #undef SCRAMBLE_DELAYED_REFS
 
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 92cb06dd94d3..faaf57a7c289 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -20,6 +20,7 @@
 #include "volumes.h"
 #include "space-info.h"
 #include "delalloc-space.h"
+#include "block-group.h"
 
 #define BITS_PER_BITMAP		(PAGE_SIZE * 8UL)
 #define MAX_CACHE_BYTES_PER_GIG	SZ_32K
diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
index f5dc115ebba0..48a03f5240f5 100644
--- a/fs/btrfs/free-space-tree.c
+++ b/fs/btrfs/free-space-tree.c
@@ -10,6 +10,7 @@
 #include "locking.h"
 #include "free-space-tree.h"
 #include "transaction.h"
+#include "block-group.h"
 
 static int __add_block_group_free_space(struct btrfs_trans_handle *trans,
 					struct btrfs_block_group_cache *block_group,
diff --git a/fs/btrfs/free-space-tree.h b/fs/btrfs/free-space-tree.h
index 22b7602bde25..360d50e1cdea 100644
--- a/fs/btrfs/free-space-tree.h
+++ b/fs/btrfs/free-space-tree.h
@@ -6,6 +6,8 @@
 #ifndef BTRFS_FREE_SPACE_TREE_H
 #define BTRFS_FREE_SPACE_TREE_H
 
+struct btrfs_caching_control;
+
 /*
  * The default size for new free space bitmap items. The last bitmap in a block
  * group may be truncated, and none of the free space tree code assumes that
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8e389c51f4e9..9f45f5a0557f 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -48,6 +48,7 @@
 #include "qgroup.h"
 #include "dedupe.h"
 #include "delalloc-space.h"
+#include "block-group.h"
 
 struct btrfs_iget_args {
 	struct btrfs_key *location;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index bae04a4f09d2..0ce6de929755 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -45,6 +45,7 @@
 #include "compression.h"
 #include "space-info.h"
 #include "delalloc-space.h"
+#include "block-group.h"
 
 #ifdef CONFIG_64BIT
 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 3e6ffbbd8b0a..0765a81fa4da 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -21,7 +21,7 @@
 #include "backref.h"
 #include "extent_io.h"
 #include "qgroup.h"
-
+#include "block-group.h"
 
 /* TODO XXX FIXME
  *  - subvol delete -> delete when ref goes to 0? delete limits also?
diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index 10d9589001a9..b74daf633832 100644
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -14,6 +14,7 @@
 #include "disk-io.h"
 #include "transaction.h"
 #include "dev-replace.h"
+#include "block-group.h"
 
 #undef DEBUG
 
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 7f219851fa23..c857cdc911c7 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -21,6 +21,7 @@
 #include "qgroup.h"
 #include "print-tree.h"
 #include "delalloc-space.h"
+#include "block-group.h"
 
 /*
  * backref_node, mapping_node and tree_block start with this
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 9f0297d529d4..d4cc3e4f4126 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -18,6 +18,7 @@
 #include "check-integrity.h"
 #include "rcu-string.h"
 #include "raid56.h"
+#include "block-group.h"
 
 /*
  * This is only the first step towards a full-features scrub. It reads all
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index 4efb817d1f0f..792509ddacb9 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -11,6 +11,7 @@
 #include "ordered-data.h"
 #include "transaction.h"
 #include "math.h"
+#include "block-group.h"
 
 u64 btrfs_space_info_used(struct btrfs_space_info *s_info,
 			  bool may_use_included)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 267f74b2ea8b..d71c46f671df 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -44,6 +44,7 @@
 #include "backref.h"
 #include "space-info.h"
 #include "tests/btrfs-tests.h"
+#include "block-group.h"
 
 #include "qgroup.h"
 #define CREATE_TRACE_POINTS
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index e6493b068294..524ca61225ed 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -17,6 +17,7 @@
 #include "sysfs.h"
 #include "volumes.h"
 #include "space-info.h"
+#include "block-group.h"
 
 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
index 9238fd4f1734..aba8c9f56d3a 100644
--- a/fs/btrfs/tests/btrfs-tests.c
+++ b/fs/btrfs/tests/btrfs-tests.c
@@ -14,6 +14,7 @@
 #include "../volumes.h"
 #include "../disk-io.h"
 #include "../qgroup.h"
+#include "../block-group.h"
 
 static struct vfsmount *test_mnt = NULL;
 
diff --git a/fs/btrfs/tests/free-space-tests.c b/fs/btrfs/tests/free-space-tests.c
index af89f66f9e63..43ec7060fcd2 100644
--- a/fs/btrfs/tests/free-space-tests.c
+++ b/fs/btrfs/tests/free-space-tests.c
@@ -8,6 +8,7 @@
 #include "../ctree.h"
 #include "../disk-io.h"
 #include "../free-space-cache.h"
+#include "../block-group.h"
 
 #define BITS_PER_BITMAP		(PAGE_SIZE * 8UL)
 
diff --git a/fs/btrfs/tests/free-space-tree-tests.c b/fs/btrfs/tests/free-space-tree-tests.c
index a90dad166971..bc92df977630 100644
--- a/fs/btrfs/tests/free-space-tree-tests.c
+++ b/fs/btrfs/tests/free-space-tree-tests.c
@@ -9,6 +9,7 @@
 #include "../disk-io.h"
 #include "../free-space-tree.h"
 #include "../transaction.h"
+#include "../block-group.h"
 
 struct free_space_extent {
 	u64 start;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3b8ae1a8f02d..5ce5a5adff31 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -19,6 +19,7 @@
 #include "volumes.h"
 #include "dev-replace.h"
 #include "qgroup.h"
+#include "block-group.h"
 
 #define BTRFS_ROOT_TRANS_TAG 0
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 68bc894ec48e..09c99f56aac2 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -29,6 +29,7 @@
 #include "sysfs.h"
 #include "tree-checker.h"
 #include "space-info.h"
+#include "block-group.h"
 
 const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 	[BTRFS_RAID_RAID10] = {
-- 
2.14.3

[PATCH 03/25] btrfs: migrate the block group lookup code

[Josef Bacik]

Move these bits first as they are the easiest to move.  Export two of
the helpers so they can be moved all at once.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/Makefile      |  2 +-
 fs/btrfs/block-group.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |  7 ++++
 fs/btrfs/ctree.h       |  3 --
 fs/btrfs/extent-tree.c | 96 +-----------------------------------------------
 5 files changed, 109 insertions(+), 98 deletions(-)
 create mode 100644 fs/btrfs/block-group.c

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 76a843198bcb..82200dbca5ac 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -11,7 +11,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 	   compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
 	   reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \
 	   uuid-tree.o props.o free-space-tree.o tree-checker.o space-info.o \
-	   block-rsv.o delalloc-space.o
+	   block-rsv.o delalloc-space.o block-group.o
 
 btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
 btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
new file mode 100644
index 000000000000..f56b38bbe4b4
--- /dev/null
+++ b/fs/btrfs/block-group.c
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Facebook.  All rights reserved.
+ */
+#include "ctree.h"
+#include "block-group.h"
+
+
+/*
+ * This will return the block group at or after bytenr if contains is 0, else
+ * it will return the block group that contains the bytenr
+ */
+static struct btrfs_block_group_cache *
+block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
+			      int contains)
+{
+	struct btrfs_block_group_cache *cache, *ret = NULL;
+	struct rb_node *n;
+	u64 end, start;
+
+	spin_lock(&info->block_group_cache_lock);
+	n = info->block_group_cache_tree.rb_node;
+
+	while (n) {
+		cache = rb_entry(n, struct btrfs_block_group_cache,
+				 cache_node);
+		end = cache->key.objectid + cache->key.offset - 1;
+		start = cache->key.objectid;
+
+		if (bytenr < start) {
+			if (!contains && (!ret || start < ret->key.objectid))
+				ret = cache;
+			n = n->rb_left;
+		} else if (bytenr > start) {
+			if (contains && bytenr <= end) {
+				ret = cache;
+				break;
+			}
+			n = n->rb_right;
+		} else {
+			ret = cache;
+			break;
+		}
+	}
+	if (ret) {
+		btrfs_get_block_group(ret);
+		if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
+			info->first_logical_byte = ret->key.objectid;
+	}
+	spin_unlock(&info->block_group_cache_lock);
+
+	return ret;
+}
+
+/*
+ * return the block group that starts at or after bytenr
+ */
+struct btrfs_block_group_cache *
+btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
+{
+	return block_group_cache_tree_search(info, bytenr, 0);
+}
+
+/*
+ * return the block group that contains the given bytenr
+ */
+struct btrfs_block_group_cache *
+btrfs_lookup_block_group(struct btrfs_fs_info *info, u64 bytenr)
+{
+	return block_group_cache_tree_search(info, bytenr, 1);
+}
+
+struct btrfs_block_group_cache *
+btrfs_next_block_group(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct rb_node *node;
+
+	spin_lock(&fs_info->block_group_cache_lock);
+
+	/* If our block group was removed, we need a full search. */
+	if (RB_EMPTY_NODE(&cache->cache_node)) {
+		const u64 next_bytenr = cache->key.objectid + cache->key.offset;
+
+		spin_unlock(&fs_info->block_group_cache_lock);
+		btrfs_put_block_group(cache);
+		cache = btrfs_lookup_first_block_group(fs_info, next_bytenr); return cache;
+	}
+	node = rb_next(&cache->cache_node);
+	btrfs_put_block_group(cache);
+	if (node) {
+		cache = rb_entry(node, struct btrfs_block_group_cache,
+				 cache_node);
+		btrfs_get_block_group(cache);
+	} else
+		cache = NULL;
+	spin_unlock(&fs_info->block_group_cache_lock);
+	return cache;
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index f3f99787af86..05e5ac134140 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -153,4 +153,11 @@ btrfs_should_fragment_free_space(struct btrfs_block_group_cache *block_group)
 }
 #endif
 
+struct btrfs_block_group_cache *
+btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr);
+struct btrfs_block_group_cache *
+btrfs_lookup_block_group(struct btrfs_fs_info *info, u64 bytenr);
+struct btrfs_block_group_cache *
+btrfs_next_block_group(struct btrfs_block_group_cache *cache);
+
 #endif /* BTRFS_BLOCK_GROUP_H */
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8a904115c553..5b24ea48ed84 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2483,9 +2483,6 @@ int btrfs_pin_extent_for_log_replay(struct btrfs_fs_info *fs_info,
 int btrfs_exclude_logged_extents(struct extent_buffer *eb);
 int btrfs_cross_ref_exist(struct btrfs_root *root,
 			  u64 objectid, u64 offset, u64 bytenr);
-struct btrfs_block_group_cache *btrfs_lookup_block_group(
-						 struct btrfs_fs_info *info,
-						 u64 bytenr);
 void btrfs_get_block_group(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index aeb8daf2a640..b9af50d19b0d 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -132,52 +132,6 @@ static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
 	return 0;
 }
 
-/*
- * This will return the block group at or after bytenr if contains is 0, else
- * it will return the block group that contains the bytenr
- */
-static struct btrfs_block_group_cache *
-block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
-			      int contains)
-{
-	struct btrfs_block_group_cache *cache, *ret = NULL;
-	struct rb_node *n;
-	u64 end, start;
-
-	spin_lock(&info->block_group_cache_lock);
-	n = info->block_group_cache_tree.rb_node;
-
-	while (n) {
-		cache = rb_entry(n, struct btrfs_block_group_cache,
-				 cache_node);
-		end = cache->key.objectid + cache->key.offset - 1;
-		start = cache->key.objectid;
-
-		if (bytenr < start) {
-			if (!contains && (!ret || start < ret->key.objectid))
-				ret = cache;
-			n = n->rb_left;
-		} else if (bytenr > start) {
-			if (contains && bytenr <= end) {
-				ret = cache;
-				break;
-			}
-			n = n->rb_right;
-		} else {
-			ret = cache;
-			break;
-		}
-	}
-	if (ret) {
-		btrfs_get_block_group(ret);
-		if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
-			info->first_logical_byte = ret->key.objectid;
-	}
-	spin_unlock(&info->block_group_cache_lock);
-
-	return ret;
-}
-
 static int add_excluded_extent(struct btrfs_fs_info *fs_info,
 			       u64 start, u64 num_bytes)
 {
@@ -672,24 +626,6 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
 	return ret;
 }
 
-/*
- * return the block group that starts at or after bytenr
- */
-static struct btrfs_block_group_cache *
-btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
-{
-	return block_group_cache_tree_search(info, bytenr, 0);
-}
-
-/*
- * return the block group that contains the given bytenr
- */
-struct btrfs_block_group_cache *btrfs_lookup_block_group(
-						 struct btrfs_fs_info *info,
-						 u64 bytenr)
-{
-	return block_group_cache_tree_search(info, bytenr, 1);
-}
 
 static u64 generic_ref_to_space_flags(struct btrfs_ref *ref)
 {
@@ -3145,34 +3081,6 @@ static int write_one_cache_group(struct btrfs_trans_handle *trans,
 
 }
 
-static struct btrfs_block_group_cache *next_block_group(
-		struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	struct rb_node *node;
-
-	spin_lock(&fs_info->block_group_cache_lock);
-
-	/* If our block group was removed, we need a full search. */
-	if (RB_EMPTY_NODE(&cache->cache_node)) {
-		const u64 next_bytenr = cache->key.objectid + cache->key.offset;
-
-		spin_unlock(&fs_info->block_group_cache_lock);
-		btrfs_put_block_group(cache);
-		cache = btrfs_lookup_first_block_group(fs_info, next_bytenr); return cache;
-	}
-	node = rb_next(&cache->cache_node);
-	btrfs_put_block_group(cache);
-	if (node) {
-		cache = rb_entry(node, struct btrfs_block_group_cache,
-				 cache_node);
-		btrfs_get_block_group(cache);
-	} else
-		cache = NULL;
-	spin_unlock(&fs_info->block_group_cache_lock);
-	return cache;
-}
-
 static int cache_save_setup(struct btrfs_block_group_cache *block_group,
 			    struct btrfs_trans_handle *trans,
 			    struct btrfs_path *path)
@@ -7773,7 +7681,7 @@ void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
 			if (block_group->iref)
 				break;
 			spin_unlock(&block_group->lock);
-			block_group = next_block_group(block_group);
+			block_group = btrfs_next_block_group(block_group);
 		}
 		if (!block_group) {
 			if (last == 0)
@@ -8963,7 +8871,7 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
 	int ret = 0;
 
 	cache = btrfs_lookup_first_block_group(fs_info, range->start);
-	for (; cache; cache = next_block_group(cache)) {
+	for (; cache; cache = btrfs_next_block_group(cache)) {
 		if (cache->key.objectid >= (range->start + range->len)) {
 			btrfs_put_block_group(cache);
 			break;
-- 
2.14.3

[PATCH 04/25] btrfs: migrate the block group ref counting stuff

[Josef Bacik]

Another easy set to move over to block-group.c.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 24 ++++++++++++++++++++++++
 fs/btrfs/block-group.h |  2 ++
 fs/btrfs/ctree.h       |  3 ---
 fs/btrfs/extent-tree.c | 25 -------------------------
 4 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index f56b38bbe4b4..b15d7070bcfd 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -5,6 +5,30 @@
 #include "ctree.h"
 #include "block-group.h"
 
+void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
+{
+	atomic_inc(&cache->count);
+}
+
+void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
+{
+	if (atomic_dec_and_test(&cache->count)) {
+		WARN_ON(cache->pinned > 0);
+		WARN_ON(cache->reserved > 0);
+
+		/*
+		 * If not empty, someone is still holding mutex of
+		 * full_stripe_lock, which can only be released by caller.
+		 * And it will definitely cause use-after-free when caller
+		 * tries to release full stripe lock.
+		 *
+		 * No better way to resolve, but only to warn.
+		 */
+		WARN_ON(!RB_EMPTY_ROOT(&cache->full_stripe_locks_root.root));
+		kfree(cache->free_space_ctl);
+		kfree(cache);
+	}
+}
 
 /*
  * This will return the block group at or after bytenr if contains is 0, else
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 05e5ac134140..ddd91c7ed44a 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -159,5 +159,7 @@ struct btrfs_block_group_cache *
 btrfs_lookup_block_group(struct btrfs_fs_info *info, u64 bytenr);
 struct btrfs_block_group_cache *
 btrfs_next_block_group(struct btrfs_block_group_cache *cache);
+void btrfs_get_block_group(struct btrfs_block_group_cache *cache);
+void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 
 #endif /* BTRFS_BLOCK_GROUP_H */
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 5b24ea48ed84..4c6e643bc65d 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2466,7 +2466,6 @@ void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg);
 bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg);
-void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   unsigned long count);
 void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
@@ -2483,8 +2482,6 @@ int btrfs_pin_extent_for_log_replay(struct btrfs_fs_info *fs_info,
 int btrfs_exclude_logged_extents(struct extent_buffer *eb);
 int btrfs_cross_ref_exist(struct btrfs_root *root,
 			  u64 objectid, u64 offset, u64 bytenr);
-void btrfs_get_block_group(struct btrfs_block_group_cache *cache);
-void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root,
 					     u64 parent, u64 root_objectid,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b9af50d19b0d..01a45674382e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -67,31 +67,6 @@ static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 	return (cache->flags & bits) == bits;
 }
 
-void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
-{
-	atomic_inc(&cache->count);
-}
-
-void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
-{
-	if (atomic_dec_and_test(&cache->count)) {
-		WARN_ON(cache->pinned > 0);
-		WARN_ON(cache->reserved > 0);
-
-		/*
-		 * If not empty, someone is still holding mutex of
-		 * full_stripe_lock, which can only be released by caller.
-		 * And it will definitely cause use-after-free when caller
-		 * tries to release full stripe lock.
-		 *
-		 * No better way to resolve, but only to warn.
-		 */
-		WARN_ON(!RB_EMPTY_ROOT(&cache->full_stripe_locks_root.root));
-		kfree(cache->free_space_ctl);
-		kfree(cache);
-	}
-}
-
 /*
  * this adds the block group to the fs_info rb tree for the block group
  * cache
-- 
2.14.3

[PATCH 05/25] btrfs: migrate nocow and reservation helpers

[Josef Bacik]

These are relatively straightforward as well.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |  6 ++++
 fs/btrfs/ctree.h       |  6 ----
 fs/btrfs/extent-tree.c | 82 -------------------------------------------------
 4 files changed, 89 insertions(+), 88 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index b15d7070bcfd..aeb2c806b2b0 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -4,6 +4,7 @@
  */
 #include "ctree.h"
 #include "block-group.h"
+#include "space-info.h"
 
 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
 {
@@ -121,3 +122,85 @@ btrfs_next_block_group(struct btrfs_block_group_cache *cache)
 	spin_unlock(&fs_info->block_group_cache_lock);
 	return cache;
 }
+
+bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
+{
+	struct btrfs_block_group_cache *bg;
+	bool ret = true;
+
+	bg = btrfs_lookup_block_group(fs_info, bytenr);
+	if (!bg)
+		return false;
+
+	spin_lock(&bg->lock);
+	if (bg->ro)
+		ret = false;
+	else
+		atomic_inc(&bg->nocow_writers);
+	spin_unlock(&bg->lock);
+
+	/* no put on block group, done by btrfs_dec_nocow_writers */
+	if (!ret)
+		btrfs_put_block_group(bg);
+
+	return ret;
+
+}
+
+void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
+{
+	struct btrfs_block_group_cache *bg;
+
+	bg = btrfs_lookup_block_group(fs_info, bytenr);
+	ASSERT(bg);
+	if (atomic_dec_and_test(&bg->nocow_writers))
+		wake_up_var(&bg->nocow_writers);
+	/*
+	 * Once for our lookup and once for the lookup done by a previous call
+	 * to btrfs_inc_nocow_writers()
+	 */
+	btrfs_put_block_group(bg);
+	btrfs_put_block_group(bg);
+}
+
+void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg)
+{
+	wait_var_event(&bg->nocow_writers, !atomic_read(&bg->nocow_writers));
+}
+
+void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
+					const u64 start)
+{
+	struct btrfs_block_group_cache *bg;
+
+	bg = btrfs_lookup_block_group(fs_info, start);
+	ASSERT(bg);
+	if (atomic_dec_and_test(&bg->reservations))
+		wake_up_var(&bg->reservations);
+	btrfs_put_block_group(bg);
+}
+
+void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg)
+{
+	struct btrfs_space_info *space_info = bg->space_info;
+
+	ASSERT(bg->ro);
+
+	if (!(bg->flags & BTRFS_BLOCK_GROUP_DATA))
+		return;
+
+	/*
+	 * Our block group is read only but before we set it to read only,
+	 * some task might have had allocated an extent from it already, but it
+	 * has not yet created a respective ordered extent (and added it to a
+	 * root's list of ordered extents).
+	 * Therefore wait for any task currently allocating extents, since the
+	 * block group's reservations counter is incremented while a read lock
+	 * on the groups' semaphore is held and decremented after releasing
+	 * the read access on that semaphore and creating the ordered extent.
+	 */
+	down_write(&space_info->groups_sem);
+	up_write(&space_info->groups_sem);
+
+	wait_var_event(&bg->reservations, !atomic_read(&bg->reservations));
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index ddd91c7ed44a..bc2ed52210a3 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -161,5 +161,11 @@ struct btrfs_block_group_cache *
 btrfs_next_block_group(struct btrfs_block_group_cache *cache);
 void btrfs_get_block_group(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
+void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
+					 const u64 start);
+void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg);
+bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
+void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
+void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg);
 
 #endif /* BTRFS_BLOCK_GROUP_H */
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 4c6e643bc65d..c4ae6714e3d4 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2460,12 +2460,6 @@ static inline u64 btrfs_calc_trunc_metadata_size(struct btrfs_fs_info *fs_info,
 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * num_items;
 }
 
-void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
-					 const u64 start);
-void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg);
-bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
-void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
-void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   unsigned long count);
 void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 01a45674382e..63b594532b92 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3560,51 +3560,6 @@ int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
 	return readonly;
 }
 
-bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
-{
-	struct btrfs_block_group_cache *bg;
-	bool ret = true;
-
-	bg = btrfs_lookup_block_group(fs_info, bytenr);
-	if (!bg)
-		return false;
-
-	spin_lock(&bg->lock);
-	if (bg->ro)
-		ret = false;
-	else
-		atomic_inc(&bg->nocow_writers);
-	spin_unlock(&bg->lock);
-
-	/* no put on block group, done by btrfs_dec_nocow_writers */
-	if (!ret)
-		btrfs_put_block_group(bg);
-
-	return ret;
-
-}
-
-void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
-{
-	struct btrfs_block_group_cache *bg;
-
-	bg = btrfs_lookup_block_group(fs_info, bytenr);
-	ASSERT(bg);
-	if (atomic_dec_and_test(&bg->nocow_writers))
-		wake_up_var(&bg->nocow_writers);
-	/*
-	 * Once for our lookup and once for the lookup done by a previous call
-	 * to btrfs_inc_nocow_writers()
-	 */
-	btrfs_put_block_group(bg);
-	btrfs_put_block_group(bg);
-}
-
-void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg)
-{
-	wait_var_event(&bg->nocow_writers, !atomic_read(&bg->nocow_writers));
-}
-
 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
 {
 	u64 extra_flags = chunk_to_extended(flags) &
@@ -4279,43 +4234,6 @@ btrfs_inc_block_group_reservations(struct btrfs_block_group_cache *bg)
 	atomic_inc(&bg->reservations);
 }
 
-void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
-					const u64 start)
-{
-	struct btrfs_block_group_cache *bg;
-
-	bg = btrfs_lookup_block_group(fs_info, start);
-	ASSERT(bg);
-	if (atomic_dec_and_test(&bg->reservations))
-		wake_up_var(&bg->reservations);
-	btrfs_put_block_group(bg);
-}
-
-void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg)
-{
-	struct btrfs_space_info *space_info = bg->space_info;
-
-	ASSERT(bg->ro);
-
-	if (!(bg->flags & BTRFS_BLOCK_GROUP_DATA))
-		return;
-
-	/*
-	 * Our block group is read only but before we set it to read only,
-	 * some task might have had allocated an extent from it already, but it
-	 * has not yet created a respective ordered extent (and added it to a
-	 * root's list of ordered extents).
-	 * Therefore wait for any task currently allocating extents, since the
-	 * block group's reservations counter is incremented while a read lock
-	 * on the groups' semaphore is held and decremented after releasing
-	 * the read access on that semaphore and creating the ordered extent.
-	 */
-	down_write(&space_info->groups_sem);
-	up_write(&space_info->groups_sem);
-
-	wait_var_event(&bg->reservations, !atomic_read(&bg->reservations));
-}
-
 /**
  * btrfs_add_reserved_bytes - update the block_group and space info counters
  * @cache:	The cache we are manipulating
-- 
2.14.3

[PATCH 06/25] btrfs: export the block group caching helpers

[Josef Bacik]

This will make it so we can move them easily.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.h | 14 +++++++++++
 fs/btrfs/extent-tree.c | 65 ++++++++++++++++++++++----------------------------
 2 files changed, 43 insertions(+), 36 deletions(-)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index bc2ed52210a3..c8a63ccd6b58 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -167,5 +167,19 @@ void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg);
 bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg);
+void
+btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
+				      u64 num_bytes);
+int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache);
+int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
+			    int load_cache_only);
+
+static inline int
+btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
+{
+	smp_mb();
+	return cache->cached == BTRFS_CACHE_FINISHED ||
+		cache->cached == BTRFS_CACHE_ERROR;
+}
 
 #endif /* BTRFS_BLOCK_GROUP_H */
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 63b594532b92..82451a64f8ee 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -54,14 +54,6 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 static int find_next_key(struct btrfs_path *path, int level,
 			 struct btrfs_key *key);
 
-static noinline int
-block_group_cache_done(struct btrfs_block_group_cache *cache)
-{
-	smp_mb();
-	return cache->cached == BTRFS_CACHE_FINISHED ||
-		cache->cached == BTRFS_CACHE_ERROR;
-}
-
 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 {
 	return (cache->flags & bits) == bits;
@@ -234,9 +226,10 @@ static void fragment_free_space(struct btrfs_block_group_cache *block_group)
 #endif
 
 /*
- * this is only called by cache_block_group, since we could have freed extents
- * we need to check the pinned_extents for any extents that can't be used yet
- * since their free space will be released as soon as the transaction commits.
+ * this is only called by btrfs_cache_block_group, since we could have freed
+ * extents we need to check the pinned_extents for any extents that can't be
+ * used yet since their free space will be released as soon as the transaction
+ * commits.
  */
 u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
 		       u64 start, u64 end)
@@ -465,8 +458,8 @@ static noinline void caching_thread(struct btrfs_work *work)
 	btrfs_put_block_group(block_group);
 }
 
-static int cache_block_group(struct btrfs_block_group_cache *cache,
-			     int load_cache_only)
+static int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
+				   int load_cache_only)
 {
 	DEFINE_WAIT(wait);
 	struct btrfs_fs_info *fs_info = cache->fs_info;
@@ -3982,7 +3975,7 @@ static int update_block_group(struct btrfs_trans_handle *trans,
 		 * space back to the block group, otherwise we will leak space.
 		 */
 		if (!alloc && cache->cached == BTRFS_CACHE_NO)
-			cache_block_group(cache, 1);
+			btrfs_cache_block_group(cache, 1);
 
 		byte_in_group = bytenr - cache->key.objectid;
 		WARN_ON(byte_in_group > cache->key.offset);
@@ -4140,7 +4133,7 @@ int btrfs_pin_extent_for_log_replay(struct btrfs_fs_info *fs_info,
 	 * to one because the slow code to read in the free extents does check
 	 * the pinned extents.
 	 */
-	cache_block_group(cache, 1);
+	btrfs_cache_block_group(cache, 1);
 
 	pin_down_extent(cache, bytenr, num_bytes, 0);
 
@@ -4161,12 +4154,12 @@ static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
 	if (!block_group)
 		return -EINVAL;
 
-	cache_block_group(block_group, 0);
+	btrfs_cache_block_group(block_group, 0);
 	caching_ctl = get_caching_control(block_group);
 
 	if (!caching_ctl) {
 		/* Logic error */
-		BUG_ON(!block_group_cache_done(block_group));
+		BUG_ON(!btrfs_block_group_cache_done(block_group));
 		ret = btrfs_remove_free_space(block_group, start, num_bytes);
 	} else {
 		mutex_lock(&caching_ctl->mutex);
@@ -4310,7 +4303,7 @@ void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info)
 	list_for_each_entry_safe(caching_ctl, next,
 				 &fs_info->caching_block_groups, list) {
 		cache = caching_ctl->block_group;
-		if (block_group_cache_done(cache)) {
+		if (btrfs_block_group_cache_done(cache)) {
 			cache->last_byte_to_unpin = (u64)-1;
 			list_del_init(&caching_ctl->list);
 			put_caching_control(caching_ctl);
@@ -4942,9 +4935,9 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
  * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
  * any of the information in this block group.
  */
-static noinline void
-wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
-				u64 num_bytes)
+void
+btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
+				      u64 num_bytes)
 {
 	struct btrfs_caching_control *caching_ctl;
 
@@ -4952,14 +4945,13 @@ wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
 	if (!caching_ctl)
 		return;
 
-	wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
+	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache) ||
 		   (cache->free_space_ctl->free_space >= num_bytes));
 
 	put_caching_control(caching_ctl);
 }
 
-static noinline int
-wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
+int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
 {
 	struct btrfs_caching_control *caching_ctl;
 	int ret = 0;
@@ -4968,7 +4960,7 @@ wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
 	if (!caching_ctl)
 		return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
 
-	wait_event(caching_ctl->wait, block_group_cache_done(cache));
+	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache));
 	if (cache->cached == BTRFS_CACHE_ERROR)
 		ret = -EIO;
 	put_caching_control(caching_ctl);
@@ -5194,8 +5186,9 @@ static int find_free_extent_clustered(struct btrfs_block_group_cache *bg,
 		spin_unlock(&last_ptr->refill_lock);
 
 		ffe_ctl->retry_clustered = true;
-		wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
-				ffe_ctl->empty_cluster + ffe_ctl->empty_size);
+		btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
+						      ffe_ctl->empty_cluster +
+						      ffe_ctl->empty_size);
 		return -EAGAIN;
 	}
 	/*
@@ -5261,8 +5254,8 @@ static int find_free_extent_unclustered(struct btrfs_block_group_cache *bg,
 	 */
 	if (!offset && !ffe_ctl->retry_unclustered && !ffe_ctl->cached &&
 	    ffe_ctl->loop > LOOP_CACHING_NOWAIT) {
-		wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
-						ffe_ctl->empty_size);
+		btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
+						      ffe_ctl->empty_size);
 		ffe_ctl->retry_unclustered = true;
 		return -EAGAIN;
 	} else if (!offset) {
@@ -5562,10 +5555,10 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info,
 		}
 
 have_block_group:
-		ffe_ctl.cached = block_group_cache_done(block_group);
+		ffe_ctl.cached = btrfs_block_group_cache_done(block_group);
 		if (unlikely(!ffe_ctl.cached)) {
 			ffe_ctl.have_caching_bg = true;
-			ret = cache_block_group(block_group, 0);
+			ret = btrfs_cache_block_group(block_group, 0);
 			BUG_ON(ret < 0);
 			ret = 0;
 		}
@@ -7569,7 +7562,7 @@ void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
 
 		block_group = btrfs_lookup_first_block_group(info, last);
 		while (block_group) {
-			wait_block_group_cache_done(block_group);
+			btrfs_wait_block_group_cache_done(block_group);
 			spin_lock(&block_group->lock);
 			if (block_group->iref)
 				break;
@@ -8314,7 +8307,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	if (block_group->has_caching_ctl)
 		caching_ctl = get_caching_control(block_group);
 	if (block_group->cached == BTRFS_CACHE_STARTED)
-		wait_block_group_cache_done(block_group);
+		btrfs_wait_block_group_cache_done(block_group);
 	if (block_group->has_caching_ctl) {
 		down_write(&fs_info->commit_root_sem);
 		if (!caching_ctl) {
@@ -8775,14 +8768,14 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
 				cache->key.objectid + cache->key.offset);
 
 		if (end - start >= range->minlen) {
-			if (!block_group_cache_done(cache)) {
-				ret = cache_block_group(cache, 0);
+			if (!btrfs_block_group_cache_done(cache)) {
+				ret = btrfs_cache_block_group(cache, 0);
 				if (ret) {
 					bg_failed++;
 					bg_ret = ret;
 					continue;
 				}
-				ret = wait_block_group_cache_done(cache);
+				ret = btrfs_wait_block_group_cache_done(cache);
 				if (ret) {
 					bg_failed++;
 					bg_ret = ret;
-- 
2.14.3

[PATCH 07/25] btrfs: export the excluded extents helpers

[Josef Bacik]

We'll need this to move the caching stuff around.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/ctree.h       |  3 +++
 fs/btrfs/extent-tree.c | 40 +++++++++++++++++++++-------------------
 2 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index c4ae6714e3d4..409852f7af9f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2460,6 +2460,9 @@ static inline u64 btrfs_calc_trunc_metadata_size(struct btrfs_fs_info *fs_info,
 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * num_items;
 }
 
+int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
+			      u64 start, u64 num_bytes);
+void btrfs_free_excluded_extents(struct btrfs_block_group_cache *cache);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   unsigned long count);
 void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 82451a64f8ee..eea5a15802f1 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -99,8 +99,8 @@ static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
 	return 0;
 }
 
-static int add_excluded_extent(struct btrfs_fs_info *fs_info,
-			       u64 start, u64 num_bytes)
+int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
+			      u64 start, u64 num_bytes)
 {
 	u64 end = start + num_bytes - 1;
 	set_extent_bits(&fs_info->freed_extents[0],
@@ -110,7 +110,7 @@ static int add_excluded_extent(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
-static void free_excluded_extents(struct btrfs_block_group_cache *cache)
+void btrfs_free_excluded_extents(struct btrfs_block_group_cache *cache)
 {
 	struct btrfs_fs_info *fs_info = cache->fs_info;
 	u64 start, end;
@@ -135,8 +135,8 @@ static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
 	if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
 		stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
 		cache->bytes_super += stripe_len;
-		ret = add_excluded_extent(fs_info, cache->key.objectid,
-					  stripe_len);
+		ret = btrfs_add_excluded_extent(fs_info, cache->key.objectid,
+						stripe_len);
 		if (ret)
 			return ret;
 	}
@@ -169,7 +169,7 @@ static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
 			}
 
 			cache->bytes_super += len;
-			ret = add_excluded_extent(fs_info, start, len);
+			ret = btrfs_add_excluded_extent(fs_info, start, len);
 			if (ret) {
 				kfree(logical);
 				return ret;
@@ -449,7 +449,7 @@ static noinline void caching_thread(struct btrfs_work *work)
 	caching_ctl->progress = (u64)-1;
 
 	up_read(&fs_info->commit_root_sem);
-	free_excluded_extents(block_group);
+	btrfs_free_excluded_extents(block_group);
 	mutex_unlock(&caching_ctl->mutex);
 
 	wake_up(&caching_ctl->wait);
@@ -458,8 +458,8 @@ static noinline void caching_thread(struct btrfs_work *work)
 	btrfs_put_block_group(block_group);
 }
 
-static int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
-				   int load_cache_only)
+int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
+			    int load_cache_only)
 {
 	DEFINE_WAIT(wait);
 	struct btrfs_fs_info *fs_info = cache->fs_info;
@@ -557,7 +557,7 @@ static int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 		wake_up(&caching_ctl->wait);
 		if (ret == 1) {
 			put_caching_control(caching_ctl);
-			free_excluded_extents(cache);
+			btrfs_free_excluded_extents(cache);
 			return 0;
 		}
 	} else {
@@ -4165,7 +4165,8 @@ static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
 		mutex_lock(&caching_ctl->mutex);
 
 		if (start >= caching_ctl->progress) {
-			ret = add_excluded_extent(fs_info, start, num_bytes);
+			ret = btrfs_add_excluded_extent(fs_info, start,
+							num_bytes);
 		} else if (start + num_bytes <= caching_ctl->progress) {
 			ret = btrfs_remove_free_space(block_group,
 						      start, num_bytes);
@@ -4179,7 +4180,8 @@ static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
 			num_bytes = (start + num_bytes) -
 				caching_ctl->progress;
 			start = caching_ctl->progress;
-			ret = add_excluded_extent(fs_info, start, num_bytes);
+			ret = btrfs_add_excluded_extent(fs_info, start,
+							num_bytes);
 		}
 out_lock:
 		mutex_unlock(&caching_ctl->mutex);
@@ -7637,7 +7639,7 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
 		 */
 		if (block_group->cached == BTRFS_CACHE_NO ||
 		    block_group->cached == BTRFS_CACHE_ERROR)
-			free_excluded_extents(block_group);
+			btrfs_free_excluded_extents(block_group);
 
 		btrfs_remove_free_space_cache(block_group);
 		ASSERT(block_group->cached != BTRFS_CACHE_STARTED);
@@ -7939,7 +7941,7 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
 			 * We may have excluded something, so call this just in
 			 * case.
 			 */
-			free_excluded_extents(cache);
+			btrfs_free_excluded_extents(cache);
 			btrfs_put_block_group(cache);
 			goto error;
 		}
@@ -7954,14 +7956,14 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
 		if (found_key.offset == btrfs_block_group_used(&cache->item)) {
 			cache->last_byte_to_unpin = (u64)-1;
 			cache->cached = BTRFS_CACHE_FINISHED;
-			free_excluded_extents(cache);
+			btrfs_free_excluded_extents(cache);
 		} else if (btrfs_block_group_used(&cache->item) == 0) {
 			cache->last_byte_to_unpin = (u64)-1;
 			cache->cached = BTRFS_CACHE_FINISHED;
 			add_new_free_space(cache, found_key.objectid,
 					   found_key.objectid +
 					   found_key.offset);
-			free_excluded_extents(cache);
+			btrfs_free_excluded_extents(cache);
 		}
 
 		ret = btrfs_add_block_group_cache(info, cache);
@@ -8087,14 +8089,14 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 		 * We may have excluded something, so call this just in
 		 * case.
 		 */
-		free_excluded_extents(cache);
+		btrfs_free_excluded_extents(cache);
 		btrfs_put_block_group(cache);
 		return ret;
 	}
 
 	add_new_free_space(cache, chunk_offset, chunk_offset + size);
 
-	free_excluded_extents(cache);
+	btrfs_free_excluded_extents(cache);
 
 #ifdef CONFIG_BTRFS_DEBUG
 	if (btrfs_should_fragment_free_space(cache)) {
@@ -8181,7 +8183,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	 * Free the reserved super bytes from this block group before
 	 * remove it.
 	 */
-	free_excluded_extents(block_group);
+	btrfs_free_excluded_extents(block_group);
 	btrfs_free_ref_tree_range(fs_info, block_group->key.objectid,
 				  block_group->key.offset);
 
-- 
2.14.3

[PATCH 08/25] btrfs: export the caching control helpers

[Josef Bacik]

Man a lot of people use this stuff.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.h |  3 +++
 fs/btrfs/extent-tree.c | 36 ++++++++++++++++++------------------
 2 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index c8a63ccd6b58..8cac9c5f1711 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -173,6 +173,9 @@ btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
 int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache);
 int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 			    int load_cache_only);
+void btrfs_put_caching_control(struct btrfs_caching_control *ctl);
+struct btrfs_caching_control *
+btrfs_get_caching_control(struct btrfs_block_group_cache *cache);
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index eea5a15802f1..9b5853e5dd14 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -181,8 +181,8 @@ static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
 	return 0;
 }
 
-static struct btrfs_caching_control *
-get_caching_control(struct btrfs_block_group_cache *cache)
+struct btrfs_caching_control *
+btrfs_get_caching_control(struct btrfs_block_group_cache *cache)
 {
 	struct btrfs_caching_control *ctl;
 
@@ -198,7 +198,7 @@ get_caching_control(struct btrfs_block_group_cache *cache)
 	return ctl;
 }
 
-static void put_caching_control(struct btrfs_caching_control *ctl)
+void btrfs_put_caching_control(struct btrfs_caching_control *ctl)
 {
 	if (refcount_dec_and_test(&ctl->count))
 		kfree(ctl);
@@ -454,7 +454,7 @@ static noinline void caching_thread(struct btrfs_work *work)
 
 	wake_up(&caching_ctl->wait);
 
-	put_caching_control(caching_ctl);
+	btrfs_put_caching_control(caching_ctl);
 	btrfs_put_block_group(block_group);
 }
 
@@ -503,7 +503,7 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 		schedule();
 
 		finish_wait(&ctl->wait, &wait);
-		put_caching_control(ctl);
+		btrfs_put_caching_control(ctl);
 		spin_lock(&cache->lock);
 	}
 
@@ -556,7 +556,7 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 
 		wake_up(&caching_ctl->wait);
 		if (ret == 1) {
-			put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
 			btrfs_free_excluded_extents(cache);
 			return 0;
 		}
@@ -578,7 +578,7 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 	}
 
 	if (load_cache_only) {
-		put_caching_control(caching_ctl);
+		btrfs_put_caching_control(caching_ctl);
 		return 0;
 	}
 
@@ -4155,7 +4155,7 @@ static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
 		return -EINVAL;
 
 	btrfs_cache_block_group(block_group, 0);
-	caching_ctl = get_caching_control(block_group);
+	caching_ctl = btrfs_get_caching_control(block_group);
 
 	if (!caching_ctl) {
 		/* Logic error */
@@ -4185,7 +4185,7 @@ static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
 		}
 out_lock:
 		mutex_unlock(&caching_ctl->mutex);
-		put_caching_control(caching_ctl);
+		btrfs_put_caching_control(caching_ctl);
 	}
 	btrfs_put_block_group(block_group);
 	return ret;
@@ -4308,7 +4308,7 @@ void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info)
 		if (btrfs_block_group_cache_done(cache)) {
 			cache->last_byte_to_unpin = (u64)-1;
 			list_del_init(&caching_ctl->list);
-			put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
 		} else {
 			cache->last_byte_to_unpin = caching_ctl->progress;
 		}
@@ -4943,14 +4943,14 @@ btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
 {
 	struct btrfs_caching_control *caching_ctl;
 
-	caching_ctl = get_caching_control(cache);
+	caching_ctl = btrfs_get_caching_control(cache);
 	if (!caching_ctl)
 		return;
 
 	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache) ||
 		   (cache->free_space_ctl->free_space >= num_bytes));
 
-	put_caching_control(caching_ctl);
+	btrfs_put_caching_control(caching_ctl);
 }
 
 int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
@@ -4958,14 +4958,14 @@ int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
 	struct btrfs_caching_control *caching_ctl;
 	int ret = 0;
 
-	caching_ctl = get_caching_control(cache);
+	caching_ctl = btrfs_get_caching_control(cache);
 	if (!caching_ctl)
 		return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
 
 	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache));
 	if (cache->cached == BTRFS_CACHE_ERROR)
 		ret = -EIO;
-	put_caching_control(caching_ctl);
+	btrfs_put_caching_control(caching_ctl);
 	return ret;
 }
 
@@ -7606,7 +7606,7 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
 		caching_ctl = list_entry(info->caching_block_groups.next,
 					 struct btrfs_caching_control, list);
 		list_del(&caching_ctl->list);
-		put_caching_control(caching_ctl);
+		btrfs_put_caching_control(caching_ctl);
 	}
 	up_write(&info->commit_root_sem);
 
@@ -8307,7 +8307,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	}
 
 	if (block_group->has_caching_ctl)
-		caching_ctl = get_caching_control(block_group);
+		caching_ctl = btrfs_get_caching_control(block_group);
 	if (block_group->cached == BTRFS_CACHE_STARTED)
 		btrfs_wait_block_group_cache_done(block_group);
 	if (block_group->has_caching_ctl) {
@@ -8328,8 +8328,8 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 		up_write(&fs_info->commit_root_sem);
 		if (caching_ctl) {
 			/* Once for the caching bgs list and once for us. */
-			put_caching_control(caching_ctl);
-			put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
 		}
 	}
 
-- 
2.14.3

[PATCH 09/25] btrfs: temporarily export fragment_free_space

[Josef Bacik]

This is used in caching and reading block groups, so export it while we
move these chunks independently.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.h | 1 +
 fs/btrfs/extent-tree.c | 8 ++++----
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 8cac9c5f1711..b249237ef175 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -151,6 +151,7 @@ btrfs_should_fragment_free_space(struct btrfs_block_group_cache *block_group)
 	       (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
 		block_group->flags &  BTRFS_BLOCK_GROUP_DATA);
 }
+void btrfs_fragment_free_space(struct btrfs_block_group_cache *block_group);
 #endif
 
 struct btrfs_block_group_cache *
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 9b5853e5dd14..1513cae23106 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -205,7 +205,7 @@ void btrfs_put_caching_control(struct btrfs_caching_control *ctl)
 }
 
 #ifdef CONFIG_BTRFS_DEBUG
-static void fragment_free_space(struct btrfs_block_group_cache *block_group)
+void btrfs_fragment_free_space(struct btrfs_block_group_cache *block_group)
 {
 	struct btrfs_fs_info *fs_info = block_group->fs_info;
 	u64 start = block_group->key.objectid;
@@ -442,7 +442,7 @@ static noinline void caching_thread(struct btrfs_work *work)
 		block_group->space_info->bytes_used += bytes_used >> 1;
 		spin_unlock(&block_group->lock);
 		spin_unlock(&block_group->space_info->lock);
-		fragment_free_space(block_group);
+		btrfs_fragment_free_space(block_group);
 	}
 #endif
 
@@ -549,7 +549,7 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 			cache->space_info->bytes_used += bytes_used >> 1;
 			spin_unlock(&cache->lock);
 			spin_unlock(&cache->space_info->lock);
-			fragment_free_space(cache);
+			btrfs_fragment_free_space(cache);
 		}
 #endif
 		mutex_unlock(&caching_ctl->mutex);
@@ -8103,7 +8103,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 		u64 new_bytes_used = size - bytes_used;
 
 		bytes_used += new_bytes_used >> 1;
-		fragment_free_space(cache);
+		btrfs_fragment_free_space(cache);
 	}
 #endif
 	/*
-- 
2.14.3

[PATCH 10/25] btrfs: make caching_thread use btrfs_find_next_key

[Josef Bacik]

extent-tree.c has a find_next_key that just walks up the path to find
the next key, but it is used for both the caching stuff and the snapshot
delete stuff.  The snapshot deletion stuff is special so it can't really
use btrfs_find_next_key, but the caching thread stuff can.  We just need
to fix btrfs_find_next_key to deal with ->skip_locking and then it works
exactly the same as the private find_next_key helper.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/ctree.c       | 4 ++--
 fs/btrfs/extent-tree.c | 3 ++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 99a585ede79d..43137258c403 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -5623,7 +5623,7 @@ int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
 	int slot;
 	struct extent_buffer *c;
 
-	WARN_ON(!path->keep_locks);
+	WARN_ON(!path->keep_locks && !path->skip_locking);
 	while (level < BTRFS_MAX_LEVEL) {
 		if (!path->nodes[level])
 			return 1;
@@ -5639,7 +5639,7 @@ int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
 			    !path->nodes[level + 1])
 				return 1;
 
-			if (path->locks[level + 1]) {
+			if (path->locks[level + 1] || path->skip_locking) {
 				level++;
 				continue;
 			}
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1513cae23106..06aab5ef68e7 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -330,7 +330,8 @@ static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
 		if (path->slots[0] < nritems) {
 			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 		} else {
-			ret = find_next_key(path, 0, &key);
+			ret = btrfs_find_next_key(extent_root, path, &key, 0,
+						  0);
 			if (ret)
 				break;
 
-- 
2.14.3

[PATCH 11/25] btrfs: migrate the block group caching code

[Josef Bacik]

We can now just copy it over to block-group.c.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 463 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |   2 +
 fs/btrfs/ctree.h       |   2 -
 fs/btrfs/extent-tree.c | 461 ------------------------------------------------
 4 files changed, 465 insertions(+), 463 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index aeb2c806b2b0..e87bf6cd1362 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -5,6 +5,9 @@
 #include "ctree.h"
 #include "block-group.h"
 #include "space-info.h"
+#include "disk-io.h"
+#include "free-space-cache.h"
+#include "free-space-tree.h"
 
 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
 {
@@ -204,3 +207,463 @@ void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg)
 
 	wait_var_event(&bg->reservations, !atomic_read(&bg->reservations));
 }
+
+struct btrfs_caching_control *
+btrfs_get_caching_control(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_caching_control *ctl;
+
+	spin_lock(&cache->lock);
+	if (!cache->caching_ctl) {
+		spin_unlock(&cache->lock);
+		return NULL;
+	}
+
+	ctl = cache->caching_ctl;
+	refcount_inc(&ctl->count);
+	spin_unlock(&cache->lock);
+	return ctl;
+}
+
+void btrfs_put_caching_control(struct btrfs_caching_control *ctl)
+{
+	if (refcount_dec_and_test(&ctl->count))
+		kfree(ctl);
+}
+
+/*
+ * when we wait for progress in the block group caching, its because
+ * our allocation attempt failed at least once.  So, we must sleep
+ * and let some progress happen before we try again.
+ *
+ * This function will sleep at least once waiting for new free space to
+ * show up, and then it will check the block group free space numbers
+ * for our min num_bytes.  Another option is to have it go ahead
+ * and look in the rbtree for a free extent of a given size, but this
+ * is a good start.
+ *
+ * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
+ * any of the information in this block group.
+ */
+void
+btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
+				      u64 num_bytes)
+{
+	struct btrfs_caching_control *caching_ctl;
+
+	caching_ctl = btrfs_get_caching_control(cache);
+	if (!caching_ctl)
+		return;
+
+	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache) ||
+		   (cache->free_space_ctl->free_space >= num_bytes));
+
+	btrfs_put_caching_control(caching_ctl);
+}
+
+int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_caching_control *caching_ctl;
+	int ret = 0;
+
+	caching_ctl = btrfs_get_caching_control(cache);
+	if (!caching_ctl)
+		return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
+
+	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache));
+	if (cache->cached == BTRFS_CACHE_ERROR)
+		ret = -EIO;
+	btrfs_put_caching_control(caching_ctl);
+	return ret;
+}
+
+#ifdef CONFIG_BTRFS_DEBUG
+void btrfs_fragment_free_space(struct btrfs_block_group_cache *block_group)
+{
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
+	u64 start = block_group->key.objectid;
+	u64 len = block_group->key.offset;
+	u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ?
+		fs_info->nodesize : fs_info->sectorsize;
+	u64 step = chunk << 1;
+
+	while (len > chunk) {
+		btrfs_remove_free_space(block_group, start, chunk);
+		start += step;
+		if (len < step)
+			len = 0;
+		else
+			len -= step;
+	}
+}
+#endif
+
+/*
+ * this is only called by btrfs_cache_block_group, since we could have freed
+ * extents we need to check the pinned_extents for any extents that can't be
+ * used yet since their free space will be released as soon as the transaction
+ * commits.
+ */
+u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
+		       u64 start, u64 end)
+{
+	struct btrfs_fs_info *info = block_group->fs_info;
+	u64 extent_start, extent_end, size, total_added = 0;
+	int ret;
+
+	while (start < end) {
+		ret = find_first_extent_bit(info->pinned_extents, start,
+					    &extent_start, &extent_end,
+					    EXTENT_DIRTY | EXTENT_UPTODATE,
+					    NULL);
+		if (ret)
+			break;
+
+		if (extent_start <= start) {
+			start = extent_end + 1;
+		} else if (extent_start > start && extent_start < end) {
+			size = extent_start - start;
+			total_added += size;
+			ret = btrfs_add_free_space(block_group, start,
+						   size);
+			BUG_ON(ret); /* -ENOMEM or logic error */
+			start = extent_end + 1;
+		} else {
+			break;
+		}
+	}
+
+	if (start < end) {
+		size = end - start;
+		total_added += size;
+		ret = btrfs_add_free_space(block_group, start, size);
+		BUG_ON(ret); /* -ENOMEM or logic error */
+	}
+
+	return total_added;
+}
+
+static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
+{
+	struct btrfs_block_group_cache *block_group = caching_ctl->block_group;
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
+	struct btrfs_root *extent_root = fs_info->extent_root;
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	u64 total_found = 0;
+	u64 last = 0;
+	u32 nritems;
+	int ret;
+	bool wakeup = true;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
+
+#ifdef CONFIG_BTRFS_DEBUG
+	/*
+	 * If we're fragmenting we don't want to make anybody think we can
+	 * allocate from this block group until we've had a chance to fragment
+	 * the free space.
+	 */
+	if (btrfs_should_fragment_free_space(block_group))
+		wakeup = false;
+#endif
+	/*
+	 * We don't want to deadlock with somebody trying to allocate a new
+	 * extent for the extent root while also trying to search the extent
+	 * root to add free space.  So we skip locking and search the commit
+	 * root, since its read-only
+	 */
+	path->skip_locking = 1;
+	path->search_commit_root = 1;
+	path->reada = READA_FORWARD;
+
+	key.objectid = last;
+	key.offset = 0;
+	key.type = BTRFS_EXTENT_ITEM_KEY;
+
+next:
+	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+
+	leaf = path->nodes[0];
+	nritems = btrfs_header_nritems(leaf);
+
+	while (1) {
+		if (btrfs_fs_closing(fs_info) > 1) {
+			last = (u64)-1;
+			break;
+		}
+
+		if (path->slots[0] < nritems) {
+			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+		} else {
+			ret = btrfs_find_next_key(extent_root, path, &key, 0,
+						  0);
+			if (ret)
+				break;
+
+			if (need_resched() ||
+			    rwsem_is_contended(&fs_info->commit_root_sem)) {
+				if (wakeup)
+					caching_ctl->progress = last;
+				btrfs_release_path(path);
+				up_read(&fs_info->commit_root_sem);
+				mutex_unlock(&caching_ctl->mutex);
+				cond_resched();
+				mutex_lock(&caching_ctl->mutex);
+				down_read(&fs_info->commit_root_sem);
+				goto next;
+			}
+
+			ret = btrfs_next_leaf(extent_root, path);
+			if (ret < 0)
+				goto out;
+			if (ret)
+				break;
+			leaf = path->nodes[0];
+			nritems = btrfs_header_nritems(leaf);
+			continue;
+		}
+
+		if (key.objectid < last) {
+			key.objectid = last;
+			key.offset = 0;
+			key.type = BTRFS_EXTENT_ITEM_KEY;
+
+			if (wakeup)
+				caching_ctl->progress = last;
+			btrfs_release_path(path);
+			goto next;
+		}
+
+		if (key.objectid < block_group->key.objectid) {
+			path->slots[0]++;
+			continue;
+		}
+
+		if (key.objectid >= block_group->key.objectid +
+		    block_group->key.offset)
+			break;
+
+		if (key.type == BTRFS_EXTENT_ITEM_KEY ||
+		    key.type == BTRFS_METADATA_ITEM_KEY) {
+			total_found += add_new_free_space(block_group, last,
+							  key.objectid);
+			if (key.type == BTRFS_METADATA_ITEM_KEY)
+				last = key.objectid +
+					fs_info->nodesize;
+			else
+				last = key.objectid + key.offset;
+
+			if (total_found > CACHING_CTL_WAKE_UP) {
+				total_found = 0;
+				if (wakeup)
+					wake_up(&caching_ctl->wait);
+			}
+		}
+		path->slots[0]++;
+	}
+	ret = 0;
+
+	total_found += add_new_free_space(block_group, last,
+					  block_group->key.objectid +
+					  block_group->key.offset);
+	caching_ctl->progress = (u64)-1;
+
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+static noinline void caching_thread(struct btrfs_work *work)
+{
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_caching_control *caching_ctl;
+	int ret;
+
+	caching_ctl = container_of(work, struct btrfs_caching_control, work);
+	block_group = caching_ctl->block_group;
+	fs_info = block_group->fs_info;
+
+	mutex_lock(&caching_ctl->mutex);
+	down_read(&fs_info->commit_root_sem);
+
+	if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
+		ret = load_free_space_tree(caching_ctl);
+	else
+		ret = load_extent_tree_free(caching_ctl);
+
+	spin_lock(&block_group->lock);
+	block_group->caching_ctl = NULL;
+	block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;
+	spin_unlock(&block_group->lock);
+
+#ifdef CONFIG_BTRFS_DEBUG
+	if (btrfs_should_fragment_free_space(block_group)) {
+		u64 bytes_used;
+
+		spin_lock(&block_group->space_info->lock);
+		spin_lock(&block_group->lock);
+		bytes_used = block_group->key.offset -
+			btrfs_block_group_used(&block_group->item);
+		block_group->space_info->bytes_used += bytes_used >> 1;
+		spin_unlock(&block_group->lock);
+		spin_unlock(&block_group->space_info->lock);
+		btrfs_fragment_free_space(block_group);
+	}
+#endif
+
+	caching_ctl->progress = (u64)-1;
+
+	up_read(&fs_info->commit_root_sem);
+	btrfs_free_excluded_extents(block_group);
+	mutex_unlock(&caching_ctl->mutex);
+
+	wake_up(&caching_ctl->wait);
+
+	btrfs_put_caching_control(caching_ctl);
+	btrfs_put_block_group(block_group);
+}
+
+int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
+			    int load_cache_only)
+{
+	DEFINE_WAIT(wait);
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct btrfs_caching_control *caching_ctl;
+	int ret = 0;
+
+	caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
+	if (!caching_ctl)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&caching_ctl->list);
+	mutex_init(&caching_ctl->mutex);
+	init_waitqueue_head(&caching_ctl->wait);
+	caching_ctl->block_group = cache;
+	caching_ctl->progress = cache->key.objectid;
+	refcount_set(&caching_ctl->count, 1);
+	btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
+			caching_thread, NULL, NULL);
+
+	spin_lock(&cache->lock);
+	/*
+	 * This should be a rare occasion, but this could happen I think in the
+	 * case where one thread starts to load the space cache info, and then
+	 * some other thread starts a transaction commit which tries to do an
+	 * allocation while the other thread is still loading the space cache
+	 * info.  The previous loop should have kept us from choosing this block
+	 * group, but if we've moved to the state where we will wait on caching
+	 * block groups we need to first check if we're doing a fast load here,
+	 * so we can wait for it to finish, otherwise we could end up allocating
+	 * from a block group who's cache gets evicted for one reason or
+	 * another.
+	 */
+	while (cache->cached == BTRFS_CACHE_FAST) {
+		struct btrfs_caching_control *ctl;
+
+		ctl = cache->caching_ctl;
+		refcount_inc(&ctl->count);
+		prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
+		spin_unlock(&cache->lock);
+
+		schedule();
+
+		finish_wait(&ctl->wait, &wait);
+		btrfs_put_caching_control(ctl);
+		spin_lock(&cache->lock);
+	}
+
+	if (cache->cached != BTRFS_CACHE_NO) {
+		spin_unlock(&cache->lock);
+		kfree(caching_ctl);
+		return 0;
+	}
+	WARN_ON(cache->caching_ctl);
+	cache->caching_ctl = caching_ctl;
+	cache->cached = BTRFS_CACHE_FAST;
+	spin_unlock(&cache->lock);
+
+	if (btrfs_test_opt(fs_info, SPACE_CACHE)) {
+		mutex_lock(&caching_ctl->mutex);
+		ret = load_free_space_cache(cache);
+
+		spin_lock(&cache->lock);
+		if (ret == 1) {
+			cache->caching_ctl = NULL;
+			cache->cached = BTRFS_CACHE_FINISHED;
+			cache->last_byte_to_unpin = (u64)-1;
+			caching_ctl->progress = (u64)-1;
+		} else {
+			if (load_cache_only) {
+				cache->caching_ctl = NULL;
+				cache->cached = BTRFS_CACHE_NO;
+			} else {
+				cache->cached = BTRFS_CACHE_STARTED;
+				cache->has_caching_ctl = 1;
+			}
+		}
+		spin_unlock(&cache->lock);
+#ifdef CONFIG_BTRFS_DEBUG
+		if (ret == 1 &&
+		    btrfs_should_fragment_free_space(cache)) {
+			u64 bytes_used;
+
+			spin_lock(&cache->space_info->lock);
+			spin_lock(&cache->lock);
+			bytes_used = cache->key.offset -
+				btrfs_block_group_used(&cache->item);
+			cache->space_info->bytes_used += bytes_used >> 1;
+			spin_unlock(&cache->lock);
+			spin_unlock(&cache->space_info->lock);
+			btrfs_fragment_free_space(cache);
+		}
+#endif
+		mutex_unlock(&caching_ctl->mutex);
+
+		wake_up(&caching_ctl->wait);
+		if (ret == 1) {
+			btrfs_put_caching_control(caching_ctl);
+			btrfs_free_excluded_extents(cache);
+			return 0;
+		}
+	} else {
+		/*
+		 * We're either using the free space tree or no caching at all.
+		 * Set cached to the appropriate value and wakeup any waiters.
+		 */
+		spin_lock(&cache->lock);
+		if (load_cache_only) {
+			cache->caching_ctl = NULL;
+			cache->cached = BTRFS_CACHE_NO;
+		} else {
+			cache->cached = BTRFS_CACHE_STARTED;
+			cache->has_caching_ctl = 1;
+		}
+		spin_unlock(&cache->lock);
+		wake_up(&caching_ctl->wait);
+	}
+
+	if (load_cache_only) {
+		btrfs_put_caching_control(caching_ctl);
+		return 0;
+	}
+
+	down_write(&fs_info->commit_root_sem);
+	refcount_inc(&caching_ctl->count);
+	list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
+	up_write(&fs_info->commit_root_sem);
+
+	btrfs_get_block_group(cache);
+
+	btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
+
+	return ret;
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index b249237ef175..058b55cd6d29 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -177,6 +177,8 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 void btrfs_put_caching_control(struct btrfs_caching_control *ctl);
 struct btrfs_caching_control *
 btrfs_get_caching_control(struct btrfs_block_group_cache *cache);
+u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
+		       u64 start, u64 end);
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 409852f7af9f..3d6209aa4dc9 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2614,8 +2614,6 @@ int btrfs_start_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_end_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_wait_for_snapshot_creation(struct btrfs_root *root);
 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
-u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
-		       u64 start, u64 end);
 void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg);
 
 /* ctree.c */
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 06aab5ef68e7..c5ffa3db9533 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -181,421 +181,6 @@ static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
 	return 0;
 }
 
-struct btrfs_caching_control *
-btrfs_get_caching_control(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_caching_control *ctl;
-
-	spin_lock(&cache->lock);
-	if (!cache->caching_ctl) {
-		spin_unlock(&cache->lock);
-		return NULL;
-	}
-
-	ctl = cache->caching_ctl;
-	refcount_inc(&ctl->count);
-	spin_unlock(&cache->lock);
-	return ctl;
-}
-
-void btrfs_put_caching_control(struct btrfs_caching_control *ctl)
-{
-	if (refcount_dec_and_test(&ctl->count))
-		kfree(ctl);
-}
-
-#ifdef CONFIG_BTRFS_DEBUG
-void btrfs_fragment_free_space(struct btrfs_block_group_cache *block_group)
-{
-	struct btrfs_fs_info *fs_info = block_group->fs_info;
-	u64 start = block_group->key.objectid;
-	u64 len = block_group->key.offset;
-	u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ?
-		fs_info->nodesize : fs_info->sectorsize;
-	u64 step = chunk << 1;
-
-	while (len > chunk) {
-		btrfs_remove_free_space(block_group, start, chunk);
-		start += step;
-		if (len < step)
-			len = 0;
-		else
-			len -= step;
-	}
-}
-#endif
-
-/*
- * this is only called by btrfs_cache_block_group, since we could have freed
- * extents we need to check the pinned_extents for any extents that can't be
- * used yet since their free space will be released as soon as the transaction
- * commits.
- */
-u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
-		       u64 start, u64 end)
-{
-	struct btrfs_fs_info *info = block_group->fs_info;
-	u64 extent_start, extent_end, size, total_added = 0;
-	int ret;
-
-	while (start < end) {
-		ret = find_first_extent_bit(info->pinned_extents, start,
-					    &extent_start, &extent_end,
-					    EXTENT_DIRTY | EXTENT_UPTODATE,
-					    NULL);
-		if (ret)
-			break;
-
-		if (extent_start <= start) {
-			start = extent_end + 1;
-		} else if (extent_start > start && extent_start < end) {
-			size = extent_start - start;
-			total_added += size;
-			ret = btrfs_add_free_space(block_group, start,
-						   size);
-			BUG_ON(ret); /* -ENOMEM or logic error */
-			start = extent_end + 1;
-		} else {
-			break;
-		}
-	}
-
-	if (start < end) {
-		size = end - start;
-		total_added += size;
-		ret = btrfs_add_free_space(block_group, start, size);
-		BUG_ON(ret); /* -ENOMEM or logic error */
-	}
-
-	return total_added;
-}
-
-static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
-{
-	struct btrfs_block_group_cache *block_group = caching_ctl->block_group;
-	struct btrfs_fs_info *fs_info = block_group->fs_info;
-	struct btrfs_root *extent_root = fs_info->extent_root;
-	struct btrfs_path *path;
-	struct extent_buffer *leaf;
-	struct btrfs_key key;
-	u64 total_found = 0;
-	u64 last = 0;
-	u32 nritems;
-	int ret;
-	bool wakeup = true;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
-
-#ifdef CONFIG_BTRFS_DEBUG
-	/*
-	 * If we're fragmenting we don't want to make anybody think we can
-	 * allocate from this block group until we've had a chance to fragment
-	 * the free space.
-	 */
-	if (btrfs_should_fragment_free_space(block_group))
-		wakeup = false;
-#endif
-	/*
-	 * We don't want to deadlock with somebody trying to allocate a new
-	 * extent for the extent root while also trying to search the extent
-	 * root to add free space.  So we skip locking and search the commit
-	 * root, since its read-only
-	 */
-	path->skip_locking = 1;
-	path->search_commit_root = 1;
-	path->reada = READA_FORWARD;
-
-	key.objectid = last;
-	key.offset = 0;
-	key.type = BTRFS_EXTENT_ITEM_KEY;
-
-next:
-	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
-	if (ret < 0)
-		goto out;
-
-	leaf = path->nodes[0];
-	nritems = btrfs_header_nritems(leaf);
-
-	while (1) {
-		if (btrfs_fs_closing(fs_info) > 1) {
-			last = (u64)-1;
-			break;
-		}
-
-		if (path->slots[0] < nritems) {
-			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-		} else {
-			ret = btrfs_find_next_key(extent_root, path, &key, 0,
-						  0);
-			if (ret)
-				break;
-
-			if (need_resched() ||
-			    rwsem_is_contended(&fs_info->commit_root_sem)) {
-				if (wakeup)
-					caching_ctl->progress = last;
-				btrfs_release_path(path);
-				up_read(&fs_info->commit_root_sem);
-				mutex_unlock(&caching_ctl->mutex);
-				cond_resched();
-				mutex_lock(&caching_ctl->mutex);
-				down_read(&fs_info->commit_root_sem);
-				goto next;
-			}
-
-			ret = btrfs_next_leaf(extent_root, path);
-			if (ret < 0)
-				goto out;
-			if (ret)
-				break;
-			leaf = path->nodes[0];
-			nritems = btrfs_header_nritems(leaf);
-			continue;
-		}
-
-		if (key.objectid < last) {
-			key.objectid = last;
-			key.offset = 0;
-			key.type = BTRFS_EXTENT_ITEM_KEY;
-
-			if (wakeup)
-				caching_ctl->progress = last;
-			btrfs_release_path(path);
-			goto next;
-		}
-
-		if (key.objectid < block_group->key.objectid) {
-			path->slots[0]++;
-			continue;
-		}
-
-		if (key.objectid >= block_group->key.objectid +
-		    block_group->key.offset)
-			break;
-
-		if (key.type == BTRFS_EXTENT_ITEM_KEY ||
-		    key.type == BTRFS_METADATA_ITEM_KEY) {
-			total_found += add_new_free_space(block_group, last,
-							  key.objectid);
-			if (key.type == BTRFS_METADATA_ITEM_KEY)
-				last = key.objectid +
-					fs_info->nodesize;
-			else
-				last = key.objectid + key.offset;
-
-			if (total_found > CACHING_CTL_WAKE_UP) {
-				total_found = 0;
-				if (wakeup)
-					wake_up(&caching_ctl->wait);
-			}
-		}
-		path->slots[0]++;
-	}
-	ret = 0;
-
-	total_found += add_new_free_space(block_group, last,
-					  block_group->key.objectid +
-					  block_group->key.offset);
-	caching_ctl->progress = (u64)-1;
-
-out:
-	btrfs_free_path(path);
-	return ret;
-}
-
-static noinline void caching_thread(struct btrfs_work *work)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_fs_info *fs_info;
-	struct btrfs_caching_control *caching_ctl;
-	int ret;
-
-	caching_ctl = container_of(work, struct btrfs_caching_control, work);
-	block_group = caching_ctl->block_group;
-	fs_info = block_group->fs_info;
-
-	mutex_lock(&caching_ctl->mutex);
-	down_read(&fs_info->commit_root_sem);
-
-	if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
-		ret = load_free_space_tree(caching_ctl);
-	else
-		ret = load_extent_tree_free(caching_ctl);
-
-	spin_lock(&block_group->lock);
-	block_group->caching_ctl = NULL;
-	block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;
-	spin_unlock(&block_group->lock);
-
-#ifdef CONFIG_BTRFS_DEBUG
-	if (btrfs_should_fragment_free_space(block_group)) {
-		u64 bytes_used;
-
-		spin_lock(&block_group->space_info->lock);
-		spin_lock(&block_group->lock);
-		bytes_used = block_group->key.offset -
-			btrfs_block_group_used(&block_group->item);
-		block_group->space_info->bytes_used += bytes_used >> 1;
-		spin_unlock(&block_group->lock);
-		spin_unlock(&block_group->space_info->lock);
-		btrfs_fragment_free_space(block_group);
-	}
-#endif
-
-	caching_ctl->progress = (u64)-1;
-
-	up_read(&fs_info->commit_root_sem);
-	btrfs_free_excluded_extents(block_group);
-	mutex_unlock(&caching_ctl->mutex);
-
-	wake_up(&caching_ctl->wait);
-
-	btrfs_put_caching_control(caching_ctl);
-	btrfs_put_block_group(block_group);
-}
-
-int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
-			    int load_cache_only)
-{
-	DEFINE_WAIT(wait);
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	struct btrfs_caching_control *caching_ctl;
-	int ret = 0;
-
-	caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
-	if (!caching_ctl)
-		return -ENOMEM;
-
-	INIT_LIST_HEAD(&caching_ctl->list);
-	mutex_init(&caching_ctl->mutex);
-	init_waitqueue_head(&caching_ctl->wait);
-	caching_ctl->block_group = cache;
-	caching_ctl->progress = cache->key.objectid;
-	refcount_set(&caching_ctl->count, 1);
-	btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
-			caching_thread, NULL, NULL);
-
-	spin_lock(&cache->lock);
-	/*
-	 * This should be a rare occasion, but this could happen I think in the
-	 * case where one thread starts to load the space cache info, and then
-	 * some other thread starts a transaction commit which tries to do an
-	 * allocation while the other thread is still loading the space cache
-	 * info.  The previous loop should have kept us from choosing this block
-	 * group, but if we've moved to the state where we will wait on caching
-	 * block groups we need to first check if we're doing a fast load here,
-	 * so we can wait for it to finish, otherwise we could end up allocating
-	 * from a block group who's cache gets evicted for one reason or
-	 * another.
-	 */
-	while (cache->cached == BTRFS_CACHE_FAST) {
-		struct btrfs_caching_control *ctl;
-
-		ctl = cache->caching_ctl;
-		refcount_inc(&ctl->count);
-		prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
-		spin_unlock(&cache->lock);
-
-		schedule();
-
-		finish_wait(&ctl->wait, &wait);
-		btrfs_put_caching_control(ctl);
-		spin_lock(&cache->lock);
-	}
-
-	if (cache->cached != BTRFS_CACHE_NO) {
-		spin_unlock(&cache->lock);
-		kfree(caching_ctl);
-		return 0;
-	}
-	WARN_ON(cache->caching_ctl);
-	cache->caching_ctl = caching_ctl;
-	cache->cached = BTRFS_CACHE_FAST;
-	spin_unlock(&cache->lock);
-
-	if (btrfs_test_opt(fs_info, SPACE_CACHE)) {
-		mutex_lock(&caching_ctl->mutex);
-		ret = load_free_space_cache(cache);
-
-		spin_lock(&cache->lock);
-		if (ret == 1) {
-			cache->caching_ctl = NULL;
-			cache->cached = BTRFS_CACHE_FINISHED;
-			cache->last_byte_to_unpin = (u64)-1;
-			caching_ctl->progress = (u64)-1;
-		} else {
-			if (load_cache_only) {
-				cache->caching_ctl = NULL;
-				cache->cached = BTRFS_CACHE_NO;
-			} else {
-				cache->cached = BTRFS_CACHE_STARTED;
-				cache->has_caching_ctl = 1;
-			}
-		}
-		spin_unlock(&cache->lock);
-#ifdef CONFIG_BTRFS_DEBUG
-		if (ret == 1 &&
-		    btrfs_should_fragment_free_space(cache)) {
-			u64 bytes_used;
-
-			spin_lock(&cache->space_info->lock);
-			spin_lock(&cache->lock);
-			bytes_used = cache->key.offset -
-				btrfs_block_group_used(&cache->item);
-			cache->space_info->bytes_used += bytes_used >> 1;
-			spin_unlock(&cache->lock);
-			spin_unlock(&cache->space_info->lock);
-			btrfs_fragment_free_space(cache);
-		}
-#endif
-		mutex_unlock(&caching_ctl->mutex);
-
-		wake_up(&caching_ctl->wait);
-		if (ret == 1) {
-			btrfs_put_caching_control(caching_ctl);
-			btrfs_free_excluded_extents(cache);
-			return 0;
-		}
-	} else {
-		/*
-		 * We're either using the free space tree or no caching at all.
-		 * Set cached to the appropriate value and wakeup any waiters.
-		 */
-		spin_lock(&cache->lock);
-		if (load_cache_only) {
-			cache->caching_ctl = NULL;
-			cache->cached = BTRFS_CACHE_NO;
-		} else {
-			cache->cached = BTRFS_CACHE_STARTED;
-			cache->has_caching_ctl = 1;
-		}
-		spin_unlock(&cache->lock);
-		wake_up(&caching_ctl->wait);
-	}
-
-	if (load_cache_only) {
-		btrfs_put_caching_control(caching_ctl);
-		return 0;
-	}
-
-	down_write(&fs_info->commit_root_sem);
-	refcount_inc(&caching_ctl->count);
-	list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
-	up_write(&fs_info->commit_root_sem);
-
-	btrfs_get_block_group(cache);
-
-	btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
-
-	return ret;
-}
-
-
 static u64 generic_ref_to_space_flags(struct btrfs_ref *ref)
 {
 	if (ref->type == BTRFS_REF_METADATA) {
@@ -4924,52 +4509,6 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
 	return ret;
 }
 
-/*
- * when we wait for progress in the block group caching, its because
- * our allocation attempt failed at least once.  So, we must sleep
- * and let some progress happen before we try again.
- *
- * This function will sleep at least once waiting for new free space to
- * show up, and then it will check the block group free space numbers
- * for our min num_bytes.  Another option is to have it go ahead
- * and look in the rbtree for a free extent of a given size, but this
- * is a good start.
- *
- * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
- * any of the information in this block group.
- */
-void
-btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
-				      u64 num_bytes)
-{
-	struct btrfs_caching_control *caching_ctl;
-
-	caching_ctl = btrfs_get_caching_control(cache);
-	if (!caching_ctl)
-		return;
-
-	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache) ||
-		   (cache->free_space_ctl->free_space >= num_bytes));
-
-	btrfs_put_caching_control(caching_ctl);
-}
-
-int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_caching_control *caching_ctl;
-	int ret = 0;
-
-	caching_ctl = btrfs_get_caching_control(cache);
-	if (!caching_ctl)
-		return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
-
-	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache));
-	if (cache->cached == BTRFS_CACHE_ERROR)
-		ret = -EIO;
-	btrfs_put_caching_control(caching_ctl);
-	return ret;
-}
-
 enum btrfs_loop_type {
 	LOOP_CACHING_NOWAIT = 0,
 	LOOP_CACHING_WAIT = 1,
-- 
2.14.3

[PATCH 12/25] btrfs: temporarily export inc_block_group_ro

[Josef Bacik]

This is used in a few logical parts of the block group code, temporarily
export it so we can move things in pieces.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.h |  2 ++
 fs/btrfs/extent-tree.c | 15 ++++++++-------
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 058b55cd6d29..6a1644908556 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -188,4 +188,6 @@ btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
 		cache->cached == BTRFS_CACHE_ERROR;
 }
 
+int __btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache,
+			       int force);
 #endif /* BTRFS_BLOCK_GROUP_H */
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index c5ffa3db9533..79ef07cdff6b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -6685,7 +6685,8 @@ static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
 	return flags;
 }
 
-static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
+int __btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache,
+			       int force)
 {
 	struct btrfs_space_info *sinfo = cache->space_info;
 	u64 num_bytes;
@@ -6790,14 +6791,14 @@ int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
 			goto out;
 	}
 
-	ret = inc_block_group_ro(cache, 0);
+	ret = __btrfs_inc_block_group_ro(cache, 0);
 	if (!ret)
 		goto out;
 	alloc_flags = get_alloc_profile(fs_info, cache->space_info->flags);
 	ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
 	if (ret < 0)
 		goto out;
-	ret = inc_block_group_ro(cache, 0);
+	ret = __btrfs_inc_block_group_ro(cache, 0);
 out:
 	if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
 		alloc_flags = update_block_group_flags(fs_info, cache->flags);
@@ -7524,7 +7525,7 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
 
 		set_avail_alloc_bits(info, cache->flags);
 		if (btrfs_chunk_readonly(info, cache->key.objectid)) {
-			inc_block_group_ro(cache, 1);
+			__btrfs_inc_block_group_ro(cache, 1);
 		} else if (btrfs_block_group_used(&cache->item) == 0) {
 			ASSERT(list_empty(&cache->bg_list));
 			btrfs_mark_bg_unused(cache);
@@ -7546,11 +7547,11 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
 		list_for_each_entry(cache,
 				&space_info->block_groups[BTRFS_RAID_RAID0],
 				list)
-			inc_block_group_ro(cache, 1);
+			__btrfs_inc_block_group_ro(cache, 1);
 		list_for_each_entry(cache,
 				&space_info->block_groups[BTRFS_RAID_SINGLE],
 				list)
-			inc_block_group_ro(cache, 1);
+			__btrfs_inc_block_group_ro(cache, 1);
 	}
 
 	btrfs_add_raid_kobjects(info);
@@ -8058,7 +8059,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
 		spin_unlock(&block_group->lock);
 
 		/* We don't want to force the issue, only flip if it's ok. */
-		ret = inc_block_group_ro(block_group, 0);
+		ret = __btrfs_inc_block_group_ro(block_group, 0);
 		up_write(&space_info->groups_sem);
 		if (ret < 0) {
 			ret = 0;
-- 
2.14.3

[PATCH 13/25] btrfs: migrate the block group removal code

[Josef Bacik]

This is the removal code and the unused bgs code.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 509 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |   7 +
 fs/btrfs/ctree.h       |   7 -
 fs/btrfs/extent-tree.c | 505 ------------------------------------------------
 4 files changed, 516 insertions(+), 512 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index e87bf6cd1362..5ffe1ff85d5c 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -8,6 +8,10 @@
 #include "disk-io.h"
 #include "free-space-cache.h"
 #include "free-space-tree.h"
+#include "disk-io.h"
+#include "volumes.h"
+#include "transaction.h"
+#include "ref-verify.h"
 
 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
 {
@@ -667,3 +671,508 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 
 	return ret;
 }
+
+static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	u64 extra_flags = chunk_to_extended(flags) &
+				BTRFS_EXTENDED_PROFILE_MASK;
+
+	write_seqlock(&fs_info->profiles_lock);
+	if (flags & BTRFS_BLOCK_GROUP_DATA)
+		fs_info->avail_data_alloc_bits &= ~extra_flags;
+	if (flags & BTRFS_BLOCK_GROUP_METADATA)
+		fs_info->avail_metadata_alloc_bits &= ~extra_flags;
+	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+		fs_info->avail_system_alloc_bits &= ~extra_flags;
+	write_sequnlock(&fs_info->profiles_lock);
+}
+
+int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
+			     u64 group_start, struct extent_map *em)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_root *root = fs_info->extent_root;
+	struct btrfs_path *path;
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_free_cluster *cluster;
+	struct btrfs_root *tree_root = fs_info->tree_root;
+	struct btrfs_key key;
+	struct inode *inode;
+	struct kobject *kobj = NULL;
+	int ret;
+	int index;
+	int factor;
+	struct btrfs_caching_control *caching_ctl = NULL;
+	bool remove_em;
+	bool remove_rsv = false;
+
+	block_group = btrfs_lookup_block_group(fs_info, group_start);
+	BUG_ON(!block_group);
+	BUG_ON(!block_group->ro);
+
+	trace_btrfs_remove_block_group(block_group);
+	/*
+	 * Free the reserved super bytes from this block group before
+	 * remove it.
+	 */
+	btrfs_free_excluded_extents(block_group);
+	btrfs_free_ref_tree_range(fs_info, block_group->key.objectid,
+				  block_group->key.offset);
+
+	memcpy(&key, &block_group->key, sizeof(key));
+	index = btrfs_bg_flags_to_raid_index(block_group->flags);
+	factor = btrfs_bg_type_to_factor(block_group->flags);
+
+	/* make sure this block group isn't part of an allocation cluster */
+	cluster = &fs_info->data_alloc_cluster;
+	spin_lock(&cluster->refill_lock);
+	btrfs_return_cluster_to_free_space(block_group, cluster);
+	spin_unlock(&cluster->refill_lock);
+
+	/*
+	 * make sure this block group isn't part of a metadata
+	 * allocation cluster
+	 */
+	cluster = &fs_info->meta_alloc_cluster;
+	spin_lock(&cluster->refill_lock);
+	btrfs_return_cluster_to_free_space(block_group, cluster);
+	spin_unlock(&cluster->refill_lock);
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * get the inode first so any iput calls done for the io_list
+	 * aren't the final iput (no unlinks allowed now)
+	 */
+	inode = lookup_free_space_inode(block_group, path);
+
+	mutex_lock(&trans->transaction->cache_write_mutex);
+	/*
+	 * Make sure our free space cache IO is done before removing the
+	 * free space inode
+	 */
+	spin_lock(&trans->transaction->dirty_bgs_lock);
+	if (!list_empty(&block_group->io_list)) {
+		list_del_init(&block_group->io_list);
+
+		WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
+
+		spin_unlock(&trans->transaction->dirty_bgs_lock);
+		btrfs_wait_cache_io(trans, block_group, path);
+		btrfs_put_block_group(block_group);
+		spin_lock(&trans->transaction->dirty_bgs_lock);
+	}
+
+	if (!list_empty(&block_group->dirty_list)) {
+		list_del_init(&block_group->dirty_list);
+		remove_rsv = true;
+		btrfs_put_block_group(block_group);
+	}
+	spin_unlock(&trans->transaction->dirty_bgs_lock);
+	mutex_unlock(&trans->transaction->cache_write_mutex);
+
+	if (!IS_ERR(inode)) {
+		ret = btrfs_orphan_add(trans, BTRFS_I(inode));
+		if (ret) {
+			btrfs_add_delayed_iput(inode);
+			goto out;
+		}
+		clear_nlink(inode);
+		/* One for the block groups ref */
+		spin_lock(&block_group->lock);
+		if (block_group->iref) {
+			block_group->iref = 0;
+			block_group->inode = NULL;
+			spin_unlock(&block_group->lock);
+			iput(inode);
+		} else {
+			spin_unlock(&block_group->lock);
+		}
+		/* One for our lookup ref */
+		btrfs_add_delayed_iput(inode);
+	}
+
+	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+	key.offset = block_group->key.objectid;
+	key.type = 0;
+
+	ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
+	if (ret < 0)
+		goto out;
+	if (ret > 0)
+		btrfs_release_path(path);
+	if (ret == 0) {
+		ret = btrfs_del_item(trans, tree_root, path);
+		if (ret)
+			goto out;
+		btrfs_release_path(path);
+	}
+
+	spin_lock(&fs_info->block_group_cache_lock);
+	rb_erase(&block_group->cache_node,
+		 &fs_info->block_group_cache_tree);
+	RB_CLEAR_NODE(&block_group->cache_node);
+
+	if (fs_info->first_logical_byte == block_group->key.objectid)
+		fs_info->first_logical_byte = (u64)-1;
+	spin_unlock(&fs_info->block_group_cache_lock);
+
+	down_write(&block_group->space_info->groups_sem);
+	/*
+	 * we must use list_del_init so people can check to see if they
+	 * are still on the list after taking the semaphore
+	 */
+	list_del_init(&block_group->list);
+	if (list_empty(&block_group->space_info->block_groups[index])) {
+		kobj = block_group->space_info->block_group_kobjs[index];
+		block_group->space_info->block_group_kobjs[index] = NULL;
+		clear_avail_alloc_bits(fs_info, block_group->flags);
+	}
+	up_write(&block_group->space_info->groups_sem);
+	if (kobj) {
+		kobject_del(kobj);
+		kobject_put(kobj);
+	}
+
+	if (block_group->has_caching_ctl)
+		caching_ctl = btrfs_get_caching_control(block_group);
+	if (block_group->cached == BTRFS_CACHE_STARTED)
+		btrfs_wait_block_group_cache_done(block_group);
+	if (block_group->has_caching_ctl) {
+		down_write(&fs_info->commit_root_sem);
+		if (!caching_ctl) {
+			struct btrfs_caching_control *ctl;
+
+			list_for_each_entry(ctl,
+				    &fs_info->caching_block_groups, list)
+				if (ctl->block_group == block_group) {
+					caching_ctl = ctl;
+					refcount_inc(&caching_ctl->count);
+					break;
+				}
+		}
+		if (caching_ctl)
+			list_del_init(&caching_ctl->list);
+		up_write(&fs_info->commit_root_sem);
+		if (caching_ctl) {
+			/* Once for the caching bgs list and once for us. */
+			btrfs_put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
+		}
+	}
+
+	spin_lock(&trans->transaction->dirty_bgs_lock);
+	WARN_ON(!list_empty(&block_group->dirty_list));
+	WARN_ON(!list_empty(&block_group->io_list));
+	spin_unlock(&trans->transaction->dirty_bgs_lock);
+
+	btrfs_remove_free_space_cache(block_group);
+
+	spin_lock(&block_group->space_info->lock);
+	list_del_init(&block_group->ro_list);
+
+	if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
+		WARN_ON(block_group->space_info->total_bytes
+			< block_group->key.offset);
+		WARN_ON(block_group->space_info->bytes_readonly
+			< block_group->key.offset);
+		WARN_ON(block_group->space_info->disk_total
+			< block_group->key.offset * factor);
+	}
+	block_group->space_info->total_bytes -= block_group->key.offset;
+	block_group->space_info->bytes_readonly -= block_group->key.offset;
+	block_group->space_info->disk_total -= block_group->key.offset * factor;
+
+	spin_unlock(&block_group->space_info->lock);
+
+	memcpy(&key, &block_group->key, sizeof(key));
+
+	mutex_lock(&fs_info->chunk_mutex);
+	spin_lock(&block_group->lock);
+	block_group->removed = 1;
+	/*
+	 * At this point trimming can't start on this block group, because we
+	 * removed the block group from the tree fs_info->block_group_cache_tree
+	 * so no one can't find it anymore and even if someone already got this
+	 * block group before we removed it from the rbtree, they have already
+	 * incremented block_group->trimming - if they didn't, they won't find
+	 * any free space entries because we already removed them all when we
+	 * called btrfs_remove_free_space_cache().
+	 *
+	 * And we must not remove the extent map from the fs_info->mapping_tree
+	 * to prevent the same logical address range and physical device space
+	 * ranges from being reused for a new block group. This is because our
+	 * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
+	 * completely transactionless, so while it is trimming a range the
+	 * currently running transaction might finish and a new one start,
+	 * allowing for new block groups to be created that can reuse the same
+	 * physical device locations unless we take this special care.
+	 *
+	 * There may also be an implicit trim operation if the file system
+	 * is mounted with -odiscard. The same protections must remain
+	 * in place until the extents have been discarded completely when
+	 * the transaction commit has completed.
+	 */
+	remove_em = (atomic_read(&block_group->trimming) == 0);
+	spin_unlock(&block_group->lock);
+
+	if (remove_em) {
+		struct extent_map_tree *em_tree;
+
+		em_tree = &fs_info->mapping_tree;
+		write_lock(&em_tree->lock);
+		remove_extent_mapping(em_tree, em);
+		write_unlock(&em_tree->lock);
+		/* once for the tree */
+		free_extent_map(em);
+	}
+
+	mutex_unlock(&fs_info->chunk_mutex);
+
+	ret = remove_block_group_free_space(trans, block_group);
+	if (ret)
+		goto out;
+
+	btrfs_put_block_group(block_group);
+	btrfs_put_block_group(block_group);
+
+	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+	if (ret > 0)
+		ret = -EIO;
+	if (ret < 0)
+		goto out;
+
+	ret = btrfs_del_item(trans, root, path);
+out:
+	if (remove_rsv)
+		btrfs_delayed_refs_rsv_release(fs_info, 1);
+	btrfs_free_path(path);
+	return ret;
+}
+
+struct btrfs_trans_handle *
+btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info,
+				     const u64 chunk_offset)
+{
+	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
+	struct extent_map *em;
+	struct map_lookup *map;
+	unsigned int num_items;
+
+	read_lock(&em_tree->lock);
+	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
+	read_unlock(&em_tree->lock);
+	ASSERT(em && em->start == chunk_offset);
+
+	/*
+	 * We need to reserve 3 + N units from the metadata space info in order
+	 * to remove a block group (done at btrfs_remove_chunk() and at
+	 * btrfs_remove_block_group()), which are used for:
+	 *
+	 * 1 unit for adding the free space inode's orphan (located in the tree
+	 * of tree roots).
+	 * 1 unit for deleting the block group item (located in the extent
+	 * tree).
+	 * 1 unit for deleting the free space item (located in tree of tree
+	 * roots).
+	 * N units for deleting N device extent items corresponding to each
+	 * stripe (located in the device tree).
+	 *
+	 * In order to remove a block group we also need to reserve units in the
+	 * system space info in order to update the chunk tree (update one or
+	 * more device items and remove one chunk item), but this is done at
+	 * btrfs_remove_chunk() through a call to check_system_chunk().
+	 */
+	map = em->map_lookup;
+	num_items = 3 + map->num_stripes;
+	free_extent_map(em);
+
+	return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root,
+							   num_items, 1);
+}
+
+/*
+ * Process the unused_bgs list and remove any that don't have any allocated
+ * space inside of them.
+ */
+void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_space_info *space_info;
+	struct btrfs_trans_handle *trans;
+	int ret = 0;
+
+	if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
+		return;
+
+	spin_lock(&fs_info->unused_bgs_lock);
+	while (!list_empty(&fs_info->unused_bgs)) {
+		u64 start, end;
+		int trimming;
+
+		block_group = list_first_entry(&fs_info->unused_bgs,
+					       struct btrfs_block_group_cache,
+					       bg_list);
+		list_del_init(&block_group->bg_list);
+
+		space_info = block_group->space_info;
+
+		if (ret || btrfs_mixed_space_info(space_info)) {
+			btrfs_put_block_group(block_group);
+			continue;
+		}
+		spin_unlock(&fs_info->unused_bgs_lock);
+
+		mutex_lock(&fs_info->delete_unused_bgs_mutex);
+
+		/* Don't want to race with allocators so take the groups_sem */
+		down_write(&space_info->groups_sem);
+		spin_lock(&block_group->lock);
+		if (block_group->reserved || block_group->pinned ||
+		    btrfs_block_group_used(&block_group->item) ||
+		    block_group->ro ||
+		    list_is_singular(&block_group->list)) {
+			/*
+			 * We want to bail if we made new allocations or have
+			 * outstanding allocations in this block group.  We do
+			 * the ro check in case balance is currently acting on
+			 * this block group.
+			 */
+			trace_btrfs_skip_unused_block_group(block_group);
+			spin_unlock(&block_group->lock);
+			up_write(&space_info->groups_sem);
+			goto next;
+		}
+		spin_unlock(&block_group->lock);
+
+		/* We don't want to force the issue, only flip if it's ok. */
+		ret = __btrfs_inc_block_group_ro(block_group, 0);
+		up_write(&space_info->groups_sem);
+		if (ret < 0) {
+			ret = 0;
+			goto next;
+		}
+
+		/*
+		 * Want to do this before we do anything else so we can recover
+		 * properly if we fail to join the transaction.
+		 */
+		trans = btrfs_start_trans_remove_block_group(fs_info,
+						     block_group->key.objectid);
+		if (IS_ERR(trans)) {
+			btrfs_dec_block_group_ro(block_group);
+			ret = PTR_ERR(trans);
+			goto next;
+		}
+
+		/*
+		 * We could have pending pinned extents for this block group,
+		 * just delete them, we don't care about them anymore.
+		 */
+		start = block_group->key.objectid;
+		end = start + block_group->key.offset - 1;
+		/*
+		 * Hold the unused_bg_unpin_mutex lock to avoid racing with
+		 * btrfs_finish_extent_commit(). If we are at transaction N,
+		 * another task might be running finish_extent_commit() for the
+		 * previous transaction N - 1, and have seen a range belonging
+		 * to the block group in freed_extents[] before we were able to
+		 * clear the whole block group range from freed_extents[]. This
+		 * means that task can lookup for the block group after we
+		 * unpinned it from freed_extents[] and removed it, leading to
+		 * a BUG_ON() at btrfs_unpin_extent_range().
+		 */
+		mutex_lock(&fs_info->unused_bg_unpin_mutex);
+		ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
+				  EXTENT_DIRTY);
+		if (ret) {
+			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+			btrfs_dec_block_group_ro(block_group);
+			goto end_trans;
+		}
+		ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
+				  EXTENT_DIRTY);
+		if (ret) {
+			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+			btrfs_dec_block_group_ro(block_group);
+			goto end_trans;
+		}
+		mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+
+		/* Reset pinned so btrfs_put_block_group doesn't complain */
+		spin_lock(&space_info->lock);
+		spin_lock(&block_group->lock);
+
+		btrfs_space_info_update_bytes_pinned(fs_info, space_info,
+						     -block_group->pinned);
+		space_info->bytes_readonly += block_group->pinned;
+		percpu_counter_add_batch(&space_info->total_bytes_pinned,
+				   -block_group->pinned,
+				   BTRFS_TOTAL_BYTES_PINNED_BATCH);
+		block_group->pinned = 0;
+
+		spin_unlock(&block_group->lock);
+		spin_unlock(&space_info->lock);
+
+		/* DISCARD can flip during remount */
+		trimming = btrfs_test_opt(fs_info, DISCARD);
+
+		/* Implicit trim during transaction commit. */
+		if (trimming)
+			btrfs_get_block_group_trimming(block_group);
+
+		/*
+		 * Btrfs_remove_chunk will abort the transaction if things go
+		 * horribly wrong.
+		 */
+		ret = btrfs_remove_chunk(trans, block_group->key.objectid);
+
+		if (ret) {
+			if (trimming)
+				btrfs_put_block_group_trimming(block_group);
+			goto end_trans;
+		}
+
+		/*
+		 * If we're not mounted with -odiscard, we can just forget
+		 * about this block group. Otherwise we'll need to wait
+		 * until transaction commit to do the actual discard.
+		 */
+		if (trimming) {
+			spin_lock(&fs_info->unused_bgs_lock);
+			/*
+			 * A concurrent scrub might have added us to the list
+			 * fs_info->unused_bgs, so use a list_move operation
+			 * to add the block group to the deleted_bgs list.
+			 */
+			list_move(&block_group->bg_list,
+				  &trans->transaction->deleted_bgs);
+			spin_unlock(&fs_info->unused_bgs_lock);
+			btrfs_get_block_group(block_group);
+		}
+end_trans:
+		btrfs_end_transaction(trans);
+next:
+		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+		btrfs_put_block_group(block_group);
+		spin_lock(&fs_info->unused_bgs_lock);
+	}
+	spin_unlock(&fs_info->unused_bgs_lock);
+}
+
+void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg)
+{
+	struct btrfs_fs_info *fs_info = bg->fs_info;
+
+	spin_lock(&fs_info->unused_bgs_lock);
+	if (list_empty(&bg->bg_list)) {
+		btrfs_get_block_group(bg);
+		trace_btrfs_add_unused_block_group(bg);
+		list_add_tail(&bg->bg_list, &fs_info->unused_bgs);
+	}
+	spin_unlock(&fs_info->unused_bgs_lock);
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 6a1644908556..140b6a1bdf40 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -179,6 +179,13 @@ struct btrfs_caching_control *
 btrfs_get_caching_control(struct btrfs_block_group_cache *cache);
 u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
 		       u64 start, u64 end);
+struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
+				struct btrfs_fs_info *fs_info,
+				const u64 chunk_offset);
+int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
+			     u64 group_start, struct extent_map *em);
+void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
+void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg);
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3d6209aa4dc9..890327c1235c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2528,12 +2528,6 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
 			   u64 bytes_used, u64 type, u64 chunk_offset,
 			   u64 size);
 void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info);
-struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
-				struct btrfs_fs_info *fs_info,
-				const u64 chunk_offset);
-int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
-			     u64 group_start, struct extent_map *em);
-void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *cache);
 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
@@ -2614,7 +2608,6 @@ int btrfs_start_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_end_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_wait_for_snapshot_creation(struct btrfs_root *root);
 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
-void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg);
 
 /* ctree.c */
 int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 79ef07cdff6b..1a101fc55007 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7681,498 +7681,6 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 	return 0;
 }
 
-static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 extra_flags = chunk_to_extended(flags) &
-				BTRFS_EXTENDED_PROFILE_MASK;
-
-	write_seqlock(&fs_info->profiles_lock);
-	if (flags & BTRFS_BLOCK_GROUP_DATA)
-		fs_info->avail_data_alloc_bits &= ~extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_METADATA)
-		fs_info->avail_metadata_alloc_bits &= ~extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-		fs_info->avail_system_alloc_bits &= ~extra_flags;
-	write_sequnlock(&fs_info->profiles_lock);
-}
-
-int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
-			     u64 group_start, struct extent_map *em)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_root *root = fs_info->extent_root;
-	struct btrfs_path *path;
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_free_cluster *cluster;
-	struct btrfs_root *tree_root = fs_info->tree_root;
-	struct btrfs_key key;
-	struct inode *inode;
-	struct kobject *kobj = NULL;
-	int ret;
-	int index;
-	int factor;
-	struct btrfs_caching_control *caching_ctl = NULL;
-	bool remove_em;
-	bool remove_rsv = false;
-
-	block_group = btrfs_lookup_block_group(fs_info, group_start);
-	BUG_ON(!block_group);
-	BUG_ON(!block_group->ro);
-
-	trace_btrfs_remove_block_group(block_group);
-	/*
-	 * Free the reserved super bytes from this block group before
-	 * remove it.
-	 */
-	btrfs_free_excluded_extents(block_group);
-	btrfs_free_ref_tree_range(fs_info, block_group->key.objectid,
-				  block_group->key.offset);
-
-	memcpy(&key, &block_group->key, sizeof(key));
-	index = btrfs_bg_flags_to_raid_index(block_group->flags);
-	factor = btrfs_bg_type_to_factor(block_group->flags);
-
-	/* make sure this block group isn't part of an allocation cluster */
-	cluster = &fs_info->data_alloc_cluster;
-	spin_lock(&cluster->refill_lock);
-	btrfs_return_cluster_to_free_space(block_group, cluster);
-	spin_unlock(&cluster->refill_lock);
-
-	/*
-	 * make sure this block group isn't part of a metadata
-	 * allocation cluster
-	 */
-	cluster = &fs_info->meta_alloc_cluster;
-	spin_lock(&cluster->refill_lock);
-	btrfs_return_cluster_to_free_space(block_group, cluster);
-	spin_unlock(&cluster->refill_lock);
-
-	path = btrfs_alloc_path();
-	if (!path) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	/*
-	 * get the inode first so any iput calls done for the io_list
-	 * aren't the final iput (no unlinks allowed now)
-	 */
-	inode = lookup_free_space_inode(block_group, path);
-
-	mutex_lock(&trans->transaction->cache_write_mutex);
-	/*
-	 * Make sure our free space cache IO is done before removing the
-	 * free space inode
-	 */
-	spin_lock(&trans->transaction->dirty_bgs_lock);
-	if (!list_empty(&block_group->io_list)) {
-		list_del_init(&block_group->io_list);
-
-		WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
-
-		spin_unlock(&trans->transaction->dirty_bgs_lock);
-		btrfs_wait_cache_io(trans, block_group, path);
-		btrfs_put_block_group(block_group);
-		spin_lock(&trans->transaction->dirty_bgs_lock);
-	}
-
-	if (!list_empty(&block_group->dirty_list)) {
-		list_del_init(&block_group->dirty_list);
-		remove_rsv = true;
-		btrfs_put_block_group(block_group);
-	}
-	spin_unlock(&trans->transaction->dirty_bgs_lock);
-	mutex_unlock(&trans->transaction->cache_write_mutex);
-
-	if (!IS_ERR(inode)) {
-		ret = btrfs_orphan_add(trans, BTRFS_I(inode));
-		if (ret) {
-			btrfs_add_delayed_iput(inode);
-			goto out;
-		}
-		clear_nlink(inode);
-		/* One for the block groups ref */
-		spin_lock(&block_group->lock);
-		if (block_group->iref) {
-			block_group->iref = 0;
-			block_group->inode = NULL;
-			spin_unlock(&block_group->lock);
-			iput(inode);
-		} else {
-			spin_unlock(&block_group->lock);
-		}
-		/* One for our lookup ref */
-		btrfs_add_delayed_iput(inode);
-	}
-
-	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
-	key.offset = block_group->key.objectid;
-	key.type = 0;
-
-	ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
-	if (ret < 0)
-		goto out;
-	if (ret > 0)
-		btrfs_release_path(path);
-	if (ret == 0) {
-		ret = btrfs_del_item(trans, tree_root, path);
-		if (ret)
-			goto out;
-		btrfs_release_path(path);
-	}
-
-	spin_lock(&fs_info->block_group_cache_lock);
-	rb_erase(&block_group->cache_node,
-		 &fs_info->block_group_cache_tree);
-	RB_CLEAR_NODE(&block_group->cache_node);
-
-	if (fs_info->first_logical_byte == block_group->key.objectid)
-		fs_info->first_logical_byte = (u64)-1;
-	spin_unlock(&fs_info->block_group_cache_lock);
-
-	down_write(&block_group->space_info->groups_sem);
-	/*
-	 * we must use list_del_init so people can check to see if they
-	 * are still on the list after taking the semaphore
-	 */
-	list_del_init(&block_group->list);
-	if (list_empty(&block_group->space_info->block_groups[index])) {
-		kobj = block_group->space_info->block_group_kobjs[index];
-		block_group->space_info->block_group_kobjs[index] = NULL;
-		clear_avail_alloc_bits(fs_info, block_group->flags);
-	}
-	up_write(&block_group->space_info->groups_sem);
-	if (kobj) {
-		kobject_del(kobj);
-		kobject_put(kobj);
-	}
-
-	if (block_group->has_caching_ctl)
-		caching_ctl = btrfs_get_caching_control(block_group);
-	if (block_group->cached == BTRFS_CACHE_STARTED)
-		btrfs_wait_block_group_cache_done(block_group);
-	if (block_group->has_caching_ctl) {
-		down_write(&fs_info->commit_root_sem);
-		if (!caching_ctl) {
-			struct btrfs_caching_control *ctl;
-
-			list_for_each_entry(ctl,
-				    &fs_info->caching_block_groups, list)
-				if (ctl->block_group == block_group) {
-					caching_ctl = ctl;
-					refcount_inc(&caching_ctl->count);
-					break;
-				}
-		}
-		if (caching_ctl)
-			list_del_init(&caching_ctl->list);
-		up_write(&fs_info->commit_root_sem);
-		if (caching_ctl) {
-			/* Once for the caching bgs list and once for us. */
-			btrfs_put_caching_control(caching_ctl);
-			btrfs_put_caching_control(caching_ctl);
-		}
-	}
-
-	spin_lock(&trans->transaction->dirty_bgs_lock);
-	WARN_ON(!list_empty(&block_group->dirty_list));
-	WARN_ON(!list_empty(&block_group->io_list));
-	spin_unlock(&trans->transaction->dirty_bgs_lock);
-
-	btrfs_remove_free_space_cache(block_group);
-
-	spin_lock(&block_group->space_info->lock);
-	list_del_init(&block_group->ro_list);
-
-	if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
-		WARN_ON(block_group->space_info->total_bytes
-			< block_group->key.offset);
-		WARN_ON(block_group->space_info->bytes_readonly
-			< block_group->key.offset);
-		WARN_ON(block_group->space_info->disk_total
-			< block_group->key.offset * factor);
-	}
-	block_group->space_info->total_bytes -= block_group->key.offset;
-	block_group->space_info->bytes_readonly -= block_group->key.offset;
-	block_group->space_info->disk_total -= block_group->key.offset * factor;
-
-	spin_unlock(&block_group->space_info->lock);
-
-	memcpy(&key, &block_group->key, sizeof(key));
-
-	mutex_lock(&fs_info->chunk_mutex);
-	spin_lock(&block_group->lock);
-	block_group->removed = 1;
-	/*
-	 * At this point trimming can't start on this block group, because we
-	 * removed the block group from the tree fs_info->block_group_cache_tree
-	 * so no one can't find it anymore and even if someone already got this
-	 * block group before we removed it from the rbtree, they have already
-	 * incremented block_group->trimming - if they didn't, they won't find
-	 * any free space entries because we already removed them all when we
-	 * called btrfs_remove_free_space_cache().
-	 *
-	 * And we must not remove the extent map from the fs_info->mapping_tree
-	 * to prevent the same logical address range and physical device space
-	 * ranges from being reused for a new block group. This is because our
-	 * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
-	 * completely transactionless, so while it is trimming a range the
-	 * currently running transaction might finish and a new one start,
-	 * allowing for new block groups to be created that can reuse the same
-	 * physical device locations unless we take this special care.
-	 *
-	 * There may also be an implicit trim operation if the file system
-	 * is mounted with -odiscard. The same protections must remain
-	 * in place until the extents have been discarded completely when
-	 * the transaction commit has completed.
-	 */
-	remove_em = (atomic_read(&block_group->trimming) == 0);
-	spin_unlock(&block_group->lock);
-
-	if (remove_em) {
-		struct extent_map_tree *em_tree;
-
-		em_tree = &fs_info->mapping_tree;
-		write_lock(&em_tree->lock);
-		remove_extent_mapping(em_tree, em);
-		write_unlock(&em_tree->lock);
-		/* once for the tree */
-		free_extent_map(em);
-	}
-
-	mutex_unlock(&fs_info->chunk_mutex);
-
-	ret = remove_block_group_free_space(trans, block_group);
-	if (ret)
-		goto out;
-
-	btrfs_put_block_group(block_group);
-	btrfs_put_block_group(block_group);
-
-	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-	if (ret > 0)
-		ret = -EIO;
-	if (ret < 0)
-		goto out;
-
-	ret = btrfs_del_item(trans, root, path);
-out:
-	if (remove_rsv)
-		btrfs_delayed_refs_rsv_release(fs_info, 1);
-	btrfs_free_path(path);
-	return ret;
-}
-
-struct btrfs_trans_handle *
-btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info,
-				     const u64 chunk_offset)
-{
-	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
-	struct extent_map *em;
-	struct map_lookup *map;
-	unsigned int num_items;
-
-	read_lock(&em_tree->lock);
-	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
-	read_unlock(&em_tree->lock);
-	ASSERT(em && em->start == chunk_offset);
-
-	/*
-	 * We need to reserve 3 + N units from the metadata space info in order
-	 * to remove a block group (done at btrfs_remove_chunk() and at
-	 * btrfs_remove_block_group()), which are used for:
-	 *
-	 * 1 unit for adding the free space inode's orphan (located in the tree
-	 * of tree roots).
-	 * 1 unit for deleting the block group item (located in the extent
-	 * tree).
-	 * 1 unit for deleting the free space item (located in tree of tree
-	 * roots).
-	 * N units for deleting N device extent items corresponding to each
-	 * stripe (located in the device tree).
-	 *
-	 * In order to remove a block group we also need to reserve units in the
-	 * system space info in order to update the chunk tree (update one or
-	 * more device items and remove one chunk item), but this is done at
-	 * btrfs_remove_chunk() through a call to check_system_chunk().
-	 */
-	map = em->map_lookup;
-	num_items = 3 + map->num_stripes;
-	free_extent_map(em);
-
-	return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root,
-							   num_items, 1);
-}
-
-/*
- * Process the unused_bgs list and remove any that don't have any allocated
- * space inside of them.
- */
-void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_space_info *space_info;
-	struct btrfs_trans_handle *trans;
-	int ret = 0;
-
-	if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
-		return;
-
-	spin_lock(&fs_info->unused_bgs_lock);
-	while (!list_empty(&fs_info->unused_bgs)) {
-		u64 start, end;
-		int trimming;
-
-		block_group = list_first_entry(&fs_info->unused_bgs,
-					       struct btrfs_block_group_cache,
-					       bg_list);
-		list_del_init(&block_group->bg_list);
-
-		space_info = block_group->space_info;
-
-		if (ret || btrfs_mixed_space_info(space_info)) {
-			btrfs_put_block_group(block_group);
-			continue;
-		}
-		spin_unlock(&fs_info->unused_bgs_lock);
-
-		mutex_lock(&fs_info->delete_unused_bgs_mutex);
-
-		/* Don't want to race with allocators so take the groups_sem */
-		down_write(&space_info->groups_sem);
-		spin_lock(&block_group->lock);
-		if (block_group->reserved || block_group->pinned ||
-		    btrfs_block_group_used(&block_group->item) ||
-		    block_group->ro ||
-		    list_is_singular(&block_group->list)) {
-			/*
-			 * We want to bail if we made new allocations or have
-			 * outstanding allocations in this block group.  We do
-			 * the ro check in case balance is currently acting on
-			 * this block group.
-			 */
-			trace_btrfs_skip_unused_block_group(block_group);
-			spin_unlock(&block_group->lock);
-			up_write(&space_info->groups_sem);
-			goto next;
-		}
-		spin_unlock(&block_group->lock);
-
-		/* We don't want to force the issue, only flip if it's ok. */
-		ret = __btrfs_inc_block_group_ro(block_group, 0);
-		up_write(&space_info->groups_sem);
-		if (ret < 0) {
-			ret = 0;
-			goto next;
-		}
-
-		/*
-		 * Want to do this before we do anything else so we can recover
-		 * properly if we fail to join the transaction.
-		 */
-		trans = btrfs_start_trans_remove_block_group(fs_info,
-						     block_group->key.objectid);
-		if (IS_ERR(trans)) {
-			btrfs_dec_block_group_ro(block_group);
-			ret = PTR_ERR(trans);
-			goto next;
-		}
-
-		/*
-		 * We could have pending pinned extents for this block group,
-		 * just delete them, we don't care about them anymore.
-		 */
-		start = block_group->key.objectid;
-		end = start + block_group->key.offset - 1;
-		/*
-		 * Hold the unused_bg_unpin_mutex lock to avoid racing with
-		 * btrfs_finish_extent_commit(). If we are at transaction N,
-		 * another task might be running finish_extent_commit() for the
-		 * previous transaction N - 1, and have seen a range belonging
-		 * to the block group in freed_extents[] before we were able to
-		 * clear the whole block group range from freed_extents[]. This
-		 * means that task can lookup for the block group after we
-		 * unpinned it from freed_extents[] and removed it, leading to
-		 * a BUG_ON() at btrfs_unpin_extent_range().
-		 */
-		mutex_lock(&fs_info->unused_bg_unpin_mutex);
-		ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
-				  EXTENT_DIRTY);
-		if (ret) {
-			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
-			btrfs_dec_block_group_ro(block_group);
-			goto end_trans;
-		}
-		ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
-				  EXTENT_DIRTY);
-		if (ret) {
-			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
-			btrfs_dec_block_group_ro(block_group);
-			goto end_trans;
-		}
-		mutex_unlock(&fs_info->unused_bg_unpin_mutex);
-
-		/* Reset pinned so btrfs_put_block_group doesn't complain */
-		spin_lock(&space_info->lock);
-		spin_lock(&block_group->lock);
-
-		btrfs_space_info_update_bytes_pinned(fs_info, space_info,
-						     -block_group->pinned);
-		space_info->bytes_readonly += block_group->pinned;
-		percpu_counter_add_batch(&space_info->total_bytes_pinned,
-				   -block_group->pinned,
-				   BTRFS_TOTAL_BYTES_PINNED_BATCH);
-		block_group->pinned = 0;
-
-		spin_unlock(&block_group->lock);
-		spin_unlock(&space_info->lock);
-
-		/* DISCARD can flip during remount */
-		trimming = btrfs_test_opt(fs_info, DISCARD);
-
-		/* Implicit trim during transaction commit. */
-		if (trimming)
-			btrfs_get_block_group_trimming(block_group);
-
-		/*
-		 * Btrfs_remove_chunk will abort the transaction if things go
-		 * horribly wrong.
-		 */
-		ret = btrfs_remove_chunk(trans, block_group->key.objectid);
-
-		if (ret) {
-			if (trimming)
-				btrfs_put_block_group_trimming(block_group);
-			goto end_trans;
-		}
-
-		/*
-		 * If we're not mounted with -odiscard, we can just forget
-		 * about this block group. Otherwise we'll need to wait
-		 * until transaction commit to do the actual discard.
-		 */
-		if (trimming) {
-			spin_lock(&fs_info->unused_bgs_lock);
-			/*
-			 * A concurrent scrub might have added us to the list
-			 * fs_info->unused_bgs, so use a list_move operation
-			 * to add the block group to the deleted_bgs list.
-			 */
-			list_move(&block_group->bg_list,
-				  &trans->transaction->deleted_bgs);
-			spin_unlock(&fs_info->unused_bgs_lock);
-			btrfs_get_block_group(block_group);
-		}
-end_trans:
-		btrfs_end_transaction(trans);
-next:
-		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
-		btrfs_put_block_group(block_group);
-		spin_lock(&fs_info->unused_bgs_lock);
-	}
-	spin_unlock(&fs_info->unused_bgs_lock);
-}
-
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
 				   u64 start, u64 end)
 {
@@ -8411,16 +7919,3 @@ void btrfs_wait_for_snapshot_creation(struct btrfs_root *root)
 			       !atomic_read(&root->will_be_snapshotted));
 	}
 }
-
-void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg)
-{
-	struct btrfs_fs_info *fs_info = bg->fs_info;
-
-	spin_lock(&fs_info->unused_bgs_lock);
-	if (list_empty(&bg->bg_list)) {
-		btrfs_get_block_group(bg);
-		trace_btrfs_add_unused_block_group(bg);
-		list_add_tail(&bg->bg_list, &fs_info->unused_bgs);
-	}
-	spin_unlock(&fs_info->unused_bgs_lock);
-}
-- 
2.14.3

[PATCH 14/25] btrfs: export get_alloc_profile

[Josef Bacik]

This gets used directly by a bunch of the block group code, export it to
make it easier to move things around.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/ctree.h       |  1 +
 fs/btrfs/extent-tree.c | 16 ++++++++--------
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 890327c1235c..96443ebd63d2 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2463,6 +2463,7 @@ static inline u64 btrfs_calc_trunc_metadata_size(struct btrfs_fs_info *fs_info,
 int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
 			      u64 start, u64 num_bytes);
 void btrfs_free_excluded_extents(struct btrfs_block_group_cache *cache);
+u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   unsigned long count);
 void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1a101fc55007..38d757bb3666 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3234,7 +3234,7 @@ static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
 	return extended_to_chunk(flags | allowed);
 }
 
-static u64 get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
+u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
 {
 	unsigned seq;
 	u64 flags;
@@ -3267,23 +3267,23 @@ static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data)
 	else
 		flags = BTRFS_BLOCK_GROUP_METADATA;
 
-	ret = get_alloc_profile(fs_info, flags);
+	ret = btrfs_get_alloc_profile(fs_info, flags);
 	return ret;
 }
 
 u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
 {
-	return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
+	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
 }
 
 u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
 {
-	return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 }
 
 u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
 {
-	return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
+	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 }
 
 static void force_metadata_allocation(struct btrfs_fs_info *info)
@@ -6794,7 +6794,7 @@ int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
 	ret = __btrfs_inc_block_group_ro(cache, 0);
 	if (!ret)
 		goto out;
-	alloc_flags = get_alloc_profile(fs_info, cache->space_info->flags);
+	alloc_flags = btrfs_get_alloc_profile(fs_info, cache->space_info->flags);
 	ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
 	if (ret < 0)
 		goto out;
@@ -6814,7 +6814,7 @@ int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
 
 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type)
 {
-	u64 alloc_flags = get_alloc_profile(trans->fs_info, type);
+	u64 alloc_flags = btrfs_get_alloc_profile(trans->fs_info, type);
 
 	return btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
 }
@@ -7533,7 +7533,7 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
 	}
 
 	list_for_each_entry_rcu(space_info, &info->space_info, list) {
-		if (!(get_alloc_profile(info, space_info->flags) &
+		if (!(btrfs_get_alloc_profile(info, space_info->flags) &
 		      (BTRFS_BLOCK_GROUP_RAID10 |
 		       BTRFS_BLOCK_GROUP_RAID1 |
 		       BTRFS_BLOCK_GROUP_RAID5 |
-- 
2.14.3

[PATCH 15/25] btrfs: migrate the block group read/creation code

[Josef Bacik]

All of the prep work has been done so we can now cleanly move this chunk
over.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 613 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |   5 +
 fs/btrfs/ctree.h       |   5 -
 fs/btrfs/extent-tree.c | 611 ------------------------------------------------
 4 files changed, 618 insertions(+), 616 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 5ffe1ff85d5c..de9ebbcd971a 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -12,6 +12,8 @@
 #include "volumes.h"
 #include "transaction.h"
 #include "ref-verify.h"
+#include "sysfs.h"
+#include "tree-log.h"
 
 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
 {
@@ -38,6 +40,46 @@ void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
 	}
 }
 
+/*
+ * this adds the block group to the fs_info rb tree for the block group
+ * cache
+ */
+static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
+				struct btrfs_block_group_cache *block_group)
+{
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct btrfs_block_group_cache *cache;
+
+	spin_lock(&info->block_group_cache_lock);
+	p = &info->block_group_cache_tree.rb_node;
+
+	while (*p) {
+		parent = *p;
+		cache = rb_entry(parent, struct btrfs_block_group_cache,
+				 cache_node);
+		if (block_group->key.objectid < cache->key.objectid) {
+			p = &(*p)->rb_left;
+		} else if (block_group->key.objectid > cache->key.objectid) {
+			p = &(*p)->rb_right;
+		} else {
+			spin_unlock(&info->block_group_cache_lock);
+			return -EEXIST;
+		}
+	}
+
+	rb_link_node(&block_group->cache_node, parent, p);
+	rb_insert_color(&block_group->cache_node,
+			&info->block_group_cache_tree);
+
+	if (info->first_logical_byte > block_group->key.objectid)
+		info->first_logical_byte = block_group->key.objectid;
+
+	spin_unlock(&info->block_group_cache_lock);
+
+	return 0;
+}
+
 /*
  * This will return the block group at or after bytenr if contains is 0, else
  * it will return the block group that contains the bytenr
@@ -1176,3 +1218,574 @@ void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg)
 	}
 	spin_unlock(&fs_info->unused_bgs_lock);
 }
+
+static int find_first_block_group(struct btrfs_fs_info *fs_info,
+				  struct btrfs_path *path,
+				  struct btrfs_key *key)
+{
+	struct btrfs_root *root = fs_info->extent_root;
+	int ret = 0;
+	struct btrfs_key found_key;
+	struct extent_buffer *leaf;
+	struct btrfs_block_group_item bg;
+	u64 flags;
+	int slot;
+
+	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+
+	while (1) {
+		slot = path->slots[0];
+		leaf = path->nodes[0];
+		if (slot >= btrfs_header_nritems(leaf)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret == 0)
+				continue;
+			if (ret < 0)
+				goto out;
+			break;
+		}
+		btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+		if (found_key.objectid >= key->objectid &&
+		    found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
+			struct extent_map_tree *em_tree;
+			struct extent_map *em;
+
+			em_tree = &root->fs_info->mapping_tree;
+			read_lock(&em_tree->lock);
+			em = lookup_extent_mapping(em_tree, found_key.objectid,
+						   found_key.offset);
+			read_unlock(&em_tree->lock);
+			if (!em) {
+				btrfs_err(fs_info,
+			"logical %llu len %llu found bg but no related chunk",
+					  found_key.objectid, found_key.offset);
+				ret = -ENOENT;
+			} else if (em->start != found_key.objectid ||
+				   em->len != found_key.offset) {
+				btrfs_err(fs_info,
+		"block group %llu len %llu mismatch with chunk %llu len %llu",
+					  found_key.objectid, found_key.offset,
+					  em->start, em->len);
+				ret = -EUCLEAN;
+			} else {
+				read_extent_buffer(leaf, &bg,
+					btrfs_item_ptr_offset(leaf, slot),
+					sizeof(bg));
+				flags = btrfs_block_group_flags(&bg) &
+					BTRFS_BLOCK_GROUP_TYPE_MASK;
+
+				if (flags != (em->map_lookup->type &
+					      BTRFS_BLOCK_GROUP_TYPE_MASK)) {
+					btrfs_err(fs_info,
+"block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx",
+						found_key.objectid,
+						found_key.offset, flags,
+						(BTRFS_BLOCK_GROUP_TYPE_MASK &
+						 em->map_lookup->type));
+					ret = -EUCLEAN;
+				} else {
+					ret = 0;
+				}
+			}
+			free_extent_map(em);
+			goto out;
+		}
+		path->slots[0]++;
+	}
+out:
+	return ret;
+}
+
+static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	u64 extra_flags = chunk_to_extended(flags) &
+				BTRFS_EXTENDED_PROFILE_MASK;
+
+	write_seqlock(&fs_info->profiles_lock);
+	if (flags & BTRFS_BLOCK_GROUP_DATA)
+		fs_info->avail_data_alloc_bits |= extra_flags;
+	if (flags & BTRFS_BLOCK_GROUP_METADATA)
+		fs_info->avail_metadata_alloc_bits |= extra_flags;
+	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+		fs_info->avail_system_alloc_bits |= extra_flags;
+	write_sequnlock(&fs_info->profiles_lock);
+}
+
+static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	u64 bytenr;
+	u64 *logical;
+	int stripe_len;
+	int i, nr, ret;
+
+	if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
+		stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
+		cache->bytes_super += stripe_len;
+		ret = btrfs_add_excluded_extent(fs_info, cache->key.objectid,
+						stripe_len);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+		bytenr = btrfs_sb_offset(i);
+		ret = btrfs_rmap_block(fs_info, cache->key.objectid,
+				       bytenr, &logical, &nr, &stripe_len);
+		if (ret)
+			return ret;
+
+		while (nr--) {
+			u64 start, len;
+
+			if (logical[nr] > cache->key.objectid +
+			    cache->key.offset)
+				continue;
+
+			if (logical[nr] + stripe_len <= cache->key.objectid)
+				continue;
+
+			start = logical[nr];
+			if (start < cache->key.objectid) {
+				start = cache->key.objectid;
+				len = (logical[nr] + stripe_len) - start;
+			} else {
+				len = min_t(u64, stripe_len,
+					    cache->key.objectid +
+					    cache->key.offset - start);
+			}
+
+			cache->bytes_super += len;
+			ret = btrfs_add_excluded_extent(fs_info, start, len);
+			if (ret) {
+				kfree(logical);
+				return ret;
+			}
+		}
+
+		kfree(logical);
+	}
+	return 0;
+}
+
+static void link_block_group(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_space_info *space_info = cache->space_info;
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	int index = btrfs_bg_flags_to_raid_index(cache->flags);
+	bool first = false;
+
+	down_write(&space_info->groups_sem);
+	if (list_empty(&space_info->block_groups[index]))
+		first = true;
+	list_add_tail(&cache->list, &space_info->block_groups[index]);
+	up_write(&space_info->groups_sem);
+
+	if (first) {
+		struct raid_kobject *rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
+		if (!rkobj) {
+			btrfs_warn(cache->fs_info,
+				"couldn't alloc memory for raid level kobject");
+			return;
+		}
+		rkobj->flags = cache->flags;
+		kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
+
+		spin_lock(&fs_info->pending_raid_kobjs_lock);
+		list_add_tail(&rkobj->list, &fs_info->pending_raid_kobjs);
+		spin_unlock(&fs_info->pending_raid_kobjs_lock);
+		space_info->block_group_kobjs[index] = &rkobj->kobj;
+	}
+}
+
+static struct btrfs_block_group_cache *
+btrfs_create_block_group_cache(struct btrfs_fs_info *fs_info,
+			       u64 start, u64 size)
+{
+	struct btrfs_block_group_cache *cache;
+
+	cache = kzalloc(sizeof(*cache), GFP_NOFS);
+	if (!cache)
+		return NULL;
+
+	cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
+					GFP_NOFS);
+	if (!cache->free_space_ctl) {
+		kfree(cache);
+		return NULL;
+	}
+
+	cache->key.objectid = start;
+	cache->key.offset = size;
+	cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
+
+	cache->fs_info = fs_info;
+	cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start);
+	set_free_space_tree_thresholds(cache);
+
+	atomic_set(&cache->count, 1);
+	spin_lock_init(&cache->lock);
+	init_rwsem(&cache->data_rwsem);
+	INIT_LIST_HEAD(&cache->list);
+	INIT_LIST_HEAD(&cache->cluster_list);
+	INIT_LIST_HEAD(&cache->bg_list);
+	INIT_LIST_HEAD(&cache->ro_list);
+	INIT_LIST_HEAD(&cache->dirty_list);
+	INIT_LIST_HEAD(&cache->io_list);
+	btrfs_init_free_space_ctl(cache);
+	atomic_set(&cache->trimming, 0);
+	mutex_init(&cache->free_space_lock);
+	btrfs_init_full_stripe_locks_tree(&cache->full_stripe_locks_root);
+
+	return cache;
+}
+
+
+/*
+ * Iterate all chunks and verify that each of them has the corresponding block
+ * group
+ */
+static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
+{
+	struct extent_map_tree *map_tree = &fs_info->mapping_tree;
+	struct extent_map *em;
+	struct btrfs_block_group_cache *bg;
+	u64 start = 0;
+	int ret = 0;
+
+	while (1) {
+		read_lock(&map_tree->lock);
+		/*
+		 * lookup_extent_mapping will return the first extent map
+		 * intersecting the range, so setting @len to 1 is enough to
+		 * get the first chunk.
+		 */
+		em = lookup_extent_mapping(map_tree, start, 1);
+		read_unlock(&map_tree->lock);
+		if (!em)
+			break;
+
+		bg = btrfs_lookup_block_group(fs_info, em->start);
+		if (!bg) {
+			btrfs_err(fs_info,
+	"chunk start=%llu len=%llu doesn't have corresponding block group",
+				     em->start, em->len);
+			ret = -EUCLEAN;
+			free_extent_map(em);
+			break;
+		}
+		if (bg->key.objectid != em->start ||
+		    bg->key.offset != em->len ||
+		    (bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) !=
+		    (em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
+			btrfs_err(fs_info,
+"chunk start=%llu len=%llu flags=0x%llx doesn't match block group start=%llu len=%llu flags=0x%llx",
+				em->start, em->len,
+				em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK,
+				bg->key.objectid, bg->key.offset,
+				bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK);
+			ret = -EUCLEAN;
+			free_extent_map(em);
+			btrfs_put_block_group(bg);
+			break;
+		}
+		start = em->start + em->len;
+		free_extent_map(em);
+		btrfs_put_block_group(bg);
+	}
+	return ret;
+}
+
+int btrfs_read_block_groups(struct btrfs_fs_info *info)
+{
+	struct btrfs_path *path;
+	int ret;
+	struct btrfs_block_group_cache *cache;
+	struct btrfs_space_info *space_info;
+	struct btrfs_key key;
+	struct btrfs_key found_key;
+	struct extent_buffer *leaf;
+	int need_clear = 0;
+	u64 cache_gen;
+	u64 feature;
+	int mixed;
+
+	feature = btrfs_super_incompat_flags(info->super_copy);
+	mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
+
+	key.objectid = 0;
+	key.offset = 0;
+	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+	path->reada = READA_FORWARD;
+
+	cache_gen = btrfs_super_cache_generation(info->super_copy);
+	if (btrfs_test_opt(info, SPACE_CACHE) &&
+	    btrfs_super_generation(info->super_copy) != cache_gen)
+		need_clear = 1;
+	if (btrfs_test_opt(info, CLEAR_CACHE))
+		need_clear = 1;
+
+	while (1) {
+		ret = find_first_block_group(info, path, &key);
+		if (ret > 0)
+			break;
+		if (ret != 0)
+			goto error;
+
+		leaf = path->nodes[0];
+		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+		cache = btrfs_create_block_group_cache(info, found_key.objectid,
+						       found_key.offset);
+		if (!cache) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		if (need_clear) {
+			/*
+			 * When we mount with old space cache, we need to
+			 * set BTRFS_DC_CLEAR and set dirty flag.
+			 *
+			 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
+			 *    truncate the old free space cache inode and
+			 *    setup a new one.
+			 * b) Setting 'dirty flag' makes sure that we flush
+			 *    the new space cache info onto disk.
+			 */
+			if (btrfs_test_opt(info, SPACE_CACHE))
+				cache->disk_cache_state = BTRFS_DC_CLEAR;
+		}
+
+		read_extent_buffer(leaf, &cache->item,
+				   btrfs_item_ptr_offset(leaf, path->slots[0]),
+				   sizeof(cache->item));
+		cache->flags = btrfs_block_group_flags(&cache->item);
+		if (!mixed &&
+		    ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
+		    (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
+			btrfs_err(info,
+"bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
+				  cache->key.objectid);
+			ret = -EINVAL;
+			goto error;
+		}
+
+		key.objectid = found_key.objectid + found_key.offset;
+		btrfs_release_path(path);
+
+		/*
+		 * We need to exclude the super stripes now so that the space
+		 * info has super bytes accounted for, otherwise we'll think
+		 * we have more space than we actually do.
+		 */
+		ret = exclude_super_stripes(cache);
+		if (ret) {
+			/*
+			 * We may have excluded something, so call this just in
+			 * case.
+			 */
+			btrfs_free_excluded_extents(cache);
+			btrfs_put_block_group(cache);
+			goto error;
+		}
+
+		/*
+		 * check for two cases, either we are full, and therefore
+		 * don't need to bother with the caching work since we won't
+		 * find any space, or we are empty, and we can just add all
+		 * the space in and be done with it.  This saves us _a_lot_ of
+		 * time, particularly in the full case.
+		 */
+		if (found_key.offset == btrfs_block_group_used(&cache->item)) {
+			cache->last_byte_to_unpin = (u64)-1;
+			cache->cached = BTRFS_CACHE_FINISHED;
+			btrfs_free_excluded_extents(cache);
+		} else if (btrfs_block_group_used(&cache->item) == 0) {
+			cache->last_byte_to_unpin = (u64)-1;
+			cache->cached = BTRFS_CACHE_FINISHED;
+			add_new_free_space(cache, found_key.objectid,
+					   found_key.objectid +
+					   found_key.offset);
+			btrfs_free_excluded_extents(cache);
+		}
+
+		ret = btrfs_add_block_group_cache(info, cache);
+		if (ret) {
+			btrfs_remove_free_space_cache(cache);
+			btrfs_put_block_group(cache);
+			goto error;
+		}
+
+		trace_btrfs_add_block_group(info, cache, 0);
+		btrfs_update_space_info(info, cache->flags, found_key.offset,
+					btrfs_block_group_used(&cache->item),
+					cache->bytes_super, &space_info);
+
+		cache->space_info = space_info;
+
+		link_block_group(cache);
+
+		set_avail_alloc_bits(info, cache->flags);
+		if (btrfs_chunk_readonly(info, cache->key.objectid)) {
+			__btrfs_inc_block_group_ro(cache, 1);
+		} else if (btrfs_block_group_used(&cache->item) == 0) {
+			ASSERT(list_empty(&cache->bg_list));
+			btrfs_mark_bg_unused(cache);
+		}
+	}
+
+	list_for_each_entry_rcu(space_info, &info->space_info, list) {
+		if (!(btrfs_get_alloc_profile(info, space_info->flags) &
+		      (BTRFS_BLOCK_GROUP_RAID10 |
+		       BTRFS_BLOCK_GROUP_RAID1 |
+		       BTRFS_BLOCK_GROUP_RAID5 |
+		       BTRFS_BLOCK_GROUP_RAID6 |
+		       BTRFS_BLOCK_GROUP_DUP)))
+			continue;
+		/*
+		 * avoid allocating from un-mirrored block group if there are
+		 * mirrored block groups.
+		 */
+		list_for_each_entry(cache,
+				&space_info->block_groups[BTRFS_RAID_RAID0],
+				list)
+			__btrfs_inc_block_group_ro(cache, 1);
+		list_for_each_entry(cache,
+				&space_info->block_groups[BTRFS_RAID_SINGLE],
+				list)
+			__btrfs_inc_block_group_ro(cache, 1);
+	}
+
+	btrfs_add_raid_kobjects(info);
+	btrfs_init_global_block_rsv(info);
+	ret = check_chunk_block_group_mappings(info);
+error:
+	btrfs_free_path(path);
+	return ret;
+}
+
+void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_root *extent_root = fs_info->extent_root;
+	struct btrfs_block_group_item item;
+	struct btrfs_key key;
+	int ret = 0;
+
+	if (!trans->can_flush_pending_bgs)
+		return;
+
+	while (!list_empty(&trans->new_bgs)) {
+		block_group = list_first_entry(&trans->new_bgs,
+					       struct btrfs_block_group_cache,
+					       bg_list);
+		if (ret)
+			goto next;
+
+		spin_lock(&block_group->lock);
+		memcpy(&item, &block_group->item, sizeof(item));
+		memcpy(&key, &block_group->key, sizeof(key));
+		spin_unlock(&block_group->lock);
+
+		ret = btrfs_insert_item(trans, extent_root, &key, &item,
+					sizeof(item));
+		if (ret)
+			btrfs_abort_transaction(trans, ret);
+		ret = btrfs_finish_chunk_alloc(trans, key.objectid, key.offset);
+		if (ret)
+			btrfs_abort_transaction(trans, ret);
+		add_block_group_free_space(trans, block_group);
+		/* already aborted the transaction if it failed. */
+next:
+		btrfs_delayed_refs_rsv_release(fs_info, 1);
+		list_del_init(&block_group->bg_list);
+	}
+	btrfs_trans_release_chunk_metadata(trans);
+}
+
+int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
+			   u64 type, u64 chunk_offset, u64 size)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *cache;
+	int ret;
+
+	btrfs_set_log_full_commit(trans);
+
+	cache = btrfs_create_block_group_cache(fs_info, chunk_offset, size);
+	if (!cache)
+		return -ENOMEM;
+
+	btrfs_set_block_group_used(&cache->item, bytes_used);
+	btrfs_set_block_group_chunk_objectid(&cache->item,
+					     BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+	btrfs_set_block_group_flags(&cache->item, type);
+
+	cache->flags = type;
+	cache->last_byte_to_unpin = (u64)-1;
+	cache->cached = BTRFS_CACHE_FINISHED;
+	cache->needs_free_space = 1;
+	ret = exclude_super_stripes(cache);
+	if (ret) {
+		/*
+		 * We may have excluded something, so call this just in
+		 * case.
+		 */
+		btrfs_free_excluded_extents(cache);
+		btrfs_put_block_group(cache);
+		return ret;
+	}
+
+	add_new_free_space(cache, chunk_offset, chunk_offset + size);
+
+	btrfs_free_excluded_extents(cache);
+
+#ifdef CONFIG_BTRFS_DEBUG
+	if (btrfs_should_fragment_free_space(cache)) {
+		u64 new_bytes_used = size - bytes_used;
+
+		bytes_used += new_bytes_used >> 1;
+		btrfs_fragment_free_space(cache);
+	}
+#endif
+	/*
+	 * Ensure the corresponding space_info object is created and
+	 * assigned to our block group. We want our bg to be added to the rbtree
+	 * with its ->space_info set.
+	 */
+	cache->space_info = btrfs_find_space_info(fs_info, cache->flags);
+	ASSERT(cache->space_info);
+
+	ret = btrfs_add_block_group_cache(fs_info, cache);
+	if (ret) {
+		btrfs_remove_free_space_cache(cache);
+		btrfs_put_block_group(cache);
+		return ret;
+	}
+
+	/*
+	 * Now that our block group has its ->space_info set and is inserted in
+	 * the rbtree, update the space info's counters.
+	 */
+	trace_btrfs_add_block_group(fs_info, cache, 1);
+	btrfs_update_space_info(fs_info, cache->flags, size, bytes_used,
+				cache->bytes_super, &cache->space_info);
+	btrfs_update_global_block_rsv(fs_info);
+
+	link_block_group(cache);
+
+	list_add_tail(&cache->bg_list, &trans->new_bgs);
+	trans->delayed_ref_updates++;
+	btrfs_update_delayed_refs_rsv(trans);
+
+	set_avail_alloc_bits(fs_info, type);
+	return 0;
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 140b6a1bdf40..f38e726c8740 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -186,6 +186,11 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 			     u64 group_start, struct extent_map *em);
 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
 void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg);
+int btrfs_read_block_groups(struct btrfs_fs_info *info);
+int btrfs_make_block_group(struct btrfs_trans_handle *trans,
+			   u64 bytes_used, u64 type, u64 chunk_offset,
+			   u64 size);
+void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 96443ebd63d2..e36c949a25c7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2523,15 +2523,10 @@ int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr);
 int btrfs_free_block_groups(struct btrfs_fs_info *info);
-int btrfs_read_block_groups(struct btrfs_fs_info *info);
 int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr);
-int btrfs_make_block_group(struct btrfs_trans_handle *trans,
-			   u64 bytes_used, u64 type, u64 chunk_offset,
-			   u64 size);
 void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info);
 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *cache);
-void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
 u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info);
 u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info);
 u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 38d757bb3666..acb25ea7dbd0 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -59,46 +59,6 @@ static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 	return (cache->flags & bits) == bits;
 }
 
-/*
- * this adds the block group to the fs_info rb tree for the block group
- * cache
- */
-static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
-				struct btrfs_block_group_cache *block_group)
-{
-	struct rb_node **p;
-	struct rb_node *parent = NULL;
-	struct btrfs_block_group_cache *cache;
-
-	spin_lock(&info->block_group_cache_lock);
-	p = &info->block_group_cache_tree.rb_node;
-
-	while (*p) {
-		parent = *p;
-		cache = rb_entry(parent, struct btrfs_block_group_cache,
-				 cache_node);
-		if (block_group->key.objectid < cache->key.objectid) {
-			p = &(*p)->rb_left;
-		} else if (block_group->key.objectid > cache->key.objectid) {
-			p = &(*p)->rb_right;
-		} else {
-			spin_unlock(&info->block_group_cache_lock);
-			return -EEXIST;
-		}
-	}
-
-	rb_link_node(&block_group->cache_node, parent, p);
-	rb_insert_color(&block_group->cache_node,
-			&info->block_group_cache_tree);
-
-	if (info->first_logical_byte > block_group->key.objectid)
-		info->first_logical_byte = block_group->key.objectid;
-
-	spin_unlock(&info->block_group_cache_lock);
-
-	return 0;
-}
-
 int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
 			      u64 start, u64 num_bytes)
 {
@@ -124,63 +84,6 @@ void btrfs_free_excluded_extents(struct btrfs_block_group_cache *cache)
 			  start, end, EXTENT_UPTODATE);
 }
 
-static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	u64 bytenr;
-	u64 *logical;
-	int stripe_len;
-	int i, nr, ret;
-
-	if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
-		stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
-		cache->bytes_super += stripe_len;
-		ret = btrfs_add_excluded_extent(fs_info, cache->key.objectid,
-						stripe_len);
-		if (ret)
-			return ret;
-	}
-
-	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
-		bytenr = btrfs_sb_offset(i);
-		ret = btrfs_rmap_block(fs_info, cache->key.objectid,
-				       bytenr, &logical, &nr, &stripe_len);
-		if (ret)
-			return ret;
-
-		while (nr--) {
-			u64 start, len;
-
-			if (logical[nr] > cache->key.objectid +
-			    cache->key.offset)
-				continue;
-
-			if (logical[nr] + stripe_len <= cache->key.objectid)
-				continue;
-
-			start = logical[nr];
-			if (start < cache->key.objectid) {
-				start = cache->key.objectid;
-				len = (logical[nr] + stripe_len) - start;
-			} else {
-				len = min_t(u64, stripe_len,
-					    cache->key.objectid +
-					    cache->key.offset - start);
-			}
-
-			cache->bytes_super += len;
-			ret = btrfs_add_excluded_extent(fs_info, start, len);
-			if (ret) {
-				kfree(logical);
-				return ret;
-			}
-		}
-
-		kfree(logical);
-	}
-	return 0;
-}
-
 static u64 generic_ref_to_space_flags(struct btrfs_ref *ref)
 {
 	if (ref->type == BTRFS_REF_METADATA) {
@@ -3139,21 +3042,6 @@ int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
 	return readonly;
 }
 
-static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 extra_flags = chunk_to_extended(flags) &
-				BTRFS_EXTENDED_PROFILE_MASK;
-
-	write_seqlock(&fs_info->profiles_lock);
-	if (flags & BTRFS_BLOCK_GROUP_DATA)
-		fs_info->avail_data_alloc_bits |= extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_METADATA)
-		fs_info->avail_metadata_alloc_bits |= extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-		fs_info->avail_system_alloc_bits |= extra_flags;
-	write_sequnlock(&fs_info->profiles_lock);
-}
-
 /*
  * returns target flags in extended format or 0 if restripe for this
  * chunk_type is not in progress
@@ -7015,86 +6903,6 @@ int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr)
 	return ret;
 }
 
-static int find_first_block_group(struct btrfs_fs_info *fs_info,
-				  struct btrfs_path *path,
-				  struct btrfs_key *key)
-{
-	struct btrfs_root *root = fs_info->extent_root;
-	int ret = 0;
-	struct btrfs_key found_key;
-	struct extent_buffer *leaf;
-	struct btrfs_block_group_item bg;
-	u64 flags;
-	int slot;
-
-	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
-	if (ret < 0)
-		goto out;
-
-	while (1) {
-		slot = path->slots[0];
-		leaf = path->nodes[0];
-		if (slot >= btrfs_header_nritems(leaf)) {
-			ret = btrfs_next_leaf(root, path);
-			if (ret == 0)
-				continue;
-			if (ret < 0)
-				goto out;
-			break;
-		}
-		btrfs_item_key_to_cpu(leaf, &found_key, slot);
-
-		if (found_key.objectid >= key->objectid &&
-		    found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
-			struct extent_map_tree *em_tree;
-			struct extent_map *em;
-
-			em_tree = &root->fs_info->mapping_tree;
-			read_lock(&em_tree->lock);
-			em = lookup_extent_mapping(em_tree, found_key.objectid,
-						   found_key.offset);
-			read_unlock(&em_tree->lock);
-			if (!em) {
-				btrfs_err(fs_info,
-			"logical %llu len %llu found bg but no related chunk",
-					  found_key.objectid, found_key.offset);
-				ret = -ENOENT;
-			} else if (em->start != found_key.objectid ||
-				   em->len != found_key.offset) {
-				btrfs_err(fs_info,
-		"block group %llu len %llu mismatch with chunk %llu len %llu",
-					  found_key.objectid, found_key.offset,
-					  em->start, em->len);
-				ret = -EUCLEAN;
-			} else {
-				read_extent_buffer(leaf, &bg,
-					btrfs_item_ptr_offset(leaf, slot),
-					sizeof(bg));
-				flags = btrfs_block_group_flags(&bg) &
-					BTRFS_BLOCK_GROUP_TYPE_MASK;
-
-				if (flags != (em->map_lookup->type &
-					      BTRFS_BLOCK_GROUP_TYPE_MASK)) {
-					btrfs_err(fs_info,
-"block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx",
-						found_key.objectid,
-						found_key.offset, flags,
-						(BTRFS_BLOCK_GROUP_TYPE_MASK &
-						 em->map_lookup->type));
-					ret = -EUCLEAN;
-				} else {
-					ret = 0;
-				}
-			}
-			free_extent_map(em);
-			goto out;
-		}
-		path->slots[0]++;
-	}
-out:
-	return ret;
-}
-
 void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
 {
 	struct btrfs_block_group_cache *block_group;
@@ -7262,425 +7070,6 @@ void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info)
 			   "failed to add kobject for block cache, ignoring");
 }
 
-static void link_block_group(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_space_info *space_info = cache->space_info;
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	int index = btrfs_bg_flags_to_raid_index(cache->flags);
-	bool first = false;
-
-	down_write(&space_info->groups_sem);
-	if (list_empty(&space_info->block_groups[index]))
-		first = true;
-	list_add_tail(&cache->list, &space_info->block_groups[index]);
-	up_write(&space_info->groups_sem);
-
-	if (first) {
-		struct raid_kobject *rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
-		if (!rkobj) {
-			btrfs_warn(cache->fs_info,
-				"couldn't alloc memory for raid level kobject");
-			return;
-		}
-		rkobj->flags = cache->flags;
-		kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
-
-		spin_lock(&fs_info->pending_raid_kobjs_lock);
-		list_add_tail(&rkobj->list, &fs_info->pending_raid_kobjs);
-		spin_unlock(&fs_info->pending_raid_kobjs_lock);
-		space_info->block_group_kobjs[index] = &rkobj->kobj;
-	}
-}
-
-static struct btrfs_block_group_cache *
-btrfs_create_block_group_cache(struct btrfs_fs_info *fs_info,
-			       u64 start, u64 size)
-{
-	struct btrfs_block_group_cache *cache;
-
-	cache = kzalloc(sizeof(*cache), GFP_NOFS);
-	if (!cache)
-		return NULL;
-
-	cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
-					GFP_NOFS);
-	if (!cache->free_space_ctl) {
-		kfree(cache);
-		return NULL;
-	}
-
-	cache->key.objectid = start;
-	cache->key.offset = size;
-	cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
-
-	cache->fs_info = fs_info;
-	cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start);
-	set_free_space_tree_thresholds(cache);
-
-	atomic_set(&cache->count, 1);
-	spin_lock_init(&cache->lock);
-	init_rwsem(&cache->data_rwsem);
-	INIT_LIST_HEAD(&cache->list);
-	INIT_LIST_HEAD(&cache->cluster_list);
-	INIT_LIST_HEAD(&cache->bg_list);
-	INIT_LIST_HEAD(&cache->ro_list);
-	INIT_LIST_HEAD(&cache->dirty_list);
-	INIT_LIST_HEAD(&cache->io_list);
-	btrfs_init_free_space_ctl(cache);
-	atomic_set(&cache->trimming, 0);
-	mutex_init(&cache->free_space_lock);
-	btrfs_init_full_stripe_locks_tree(&cache->full_stripe_locks_root);
-
-	return cache;
-}
-
-
-/*
- * Iterate all chunks and verify that each of them has the corresponding block
- * group
- */
-static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
-{
-	struct extent_map_tree *map_tree = &fs_info->mapping_tree;
-	struct extent_map *em;
-	struct btrfs_block_group_cache *bg;
-	u64 start = 0;
-	int ret = 0;
-
-	while (1) {
-		read_lock(&map_tree->lock);
-		/*
-		 * lookup_extent_mapping will return the first extent map
-		 * intersecting the range, so setting @len to 1 is enough to
-		 * get the first chunk.
-		 */
-		em = lookup_extent_mapping(map_tree, start, 1);
-		read_unlock(&map_tree->lock);
-		if (!em)
-			break;
-
-		bg = btrfs_lookup_block_group(fs_info, em->start);
-		if (!bg) {
-			btrfs_err(fs_info,
-	"chunk start=%llu len=%llu doesn't have corresponding block group",
-				     em->start, em->len);
-			ret = -EUCLEAN;
-			free_extent_map(em);
-			break;
-		}
-		if (bg->key.objectid != em->start ||
-		    bg->key.offset != em->len ||
-		    (bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) !=
-		    (em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
-			btrfs_err(fs_info,
-"chunk start=%llu len=%llu flags=0x%llx doesn't match block group start=%llu len=%llu flags=0x%llx",
-				em->start, em->len,
-				em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK,
-				bg->key.objectid, bg->key.offset,
-				bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK);
-			ret = -EUCLEAN;
-			free_extent_map(em);
-			btrfs_put_block_group(bg);
-			break;
-		}
-		start = em->start + em->len;
-		free_extent_map(em);
-		btrfs_put_block_group(bg);
-	}
-	return ret;
-}
-
-int btrfs_read_block_groups(struct btrfs_fs_info *info)
-{
-	struct btrfs_path *path;
-	int ret;
-	struct btrfs_block_group_cache *cache;
-	struct btrfs_space_info *space_info;
-	struct btrfs_key key;
-	struct btrfs_key found_key;
-	struct extent_buffer *leaf;
-	int need_clear = 0;
-	u64 cache_gen;
-	u64 feature;
-	int mixed;
-
-	feature = btrfs_super_incompat_flags(info->super_copy);
-	mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
-
-	key.objectid = 0;
-	key.offset = 0;
-	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-	path->reada = READA_FORWARD;
-
-	cache_gen = btrfs_super_cache_generation(info->super_copy);
-	if (btrfs_test_opt(info, SPACE_CACHE) &&
-	    btrfs_super_generation(info->super_copy) != cache_gen)
-		need_clear = 1;
-	if (btrfs_test_opt(info, CLEAR_CACHE))
-		need_clear = 1;
-
-	while (1) {
-		ret = find_first_block_group(info, path, &key);
-		if (ret > 0)
-			break;
-		if (ret != 0)
-			goto error;
-
-		leaf = path->nodes[0];
-		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
-
-		cache = btrfs_create_block_group_cache(info, found_key.objectid,
-						       found_key.offset);
-		if (!cache) {
-			ret = -ENOMEM;
-			goto error;
-		}
-
-		if (need_clear) {
-			/*
-			 * When we mount with old space cache, we need to
-			 * set BTRFS_DC_CLEAR and set dirty flag.
-			 *
-			 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
-			 *    truncate the old free space cache inode and
-			 *    setup a new one.
-			 * b) Setting 'dirty flag' makes sure that we flush
-			 *    the new space cache info onto disk.
-			 */
-			if (btrfs_test_opt(info, SPACE_CACHE))
-				cache->disk_cache_state = BTRFS_DC_CLEAR;
-		}
-
-		read_extent_buffer(leaf, &cache->item,
-				   btrfs_item_ptr_offset(leaf, path->slots[0]),
-				   sizeof(cache->item));
-		cache->flags = btrfs_block_group_flags(&cache->item);
-		if (!mixed &&
-		    ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
-		    (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
-			btrfs_err(info,
-"bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
-				  cache->key.objectid);
-			ret = -EINVAL;
-			goto error;
-		}
-
-		key.objectid = found_key.objectid + found_key.offset;
-		btrfs_release_path(path);
-
-		/*
-		 * We need to exclude the super stripes now so that the space
-		 * info has super bytes accounted for, otherwise we'll think
-		 * we have more space than we actually do.
-		 */
-		ret = exclude_super_stripes(cache);
-		if (ret) {
-			/*
-			 * We may have excluded something, so call this just in
-			 * case.
-			 */
-			btrfs_free_excluded_extents(cache);
-			btrfs_put_block_group(cache);
-			goto error;
-		}
-
-		/*
-		 * check for two cases, either we are full, and therefore
-		 * don't need to bother with the caching work since we won't
-		 * find any space, or we are empty, and we can just add all
-		 * the space in and be done with it.  This saves us _a_lot_ of
-		 * time, particularly in the full case.
-		 */
-		if (found_key.offset == btrfs_block_group_used(&cache->item)) {
-			cache->last_byte_to_unpin = (u64)-1;
-			cache->cached = BTRFS_CACHE_FINISHED;
-			btrfs_free_excluded_extents(cache);
-		} else if (btrfs_block_group_used(&cache->item) == 0) {
-			cache->last_byte_to_unpin = (u64)-1;
-			cache->cached = BTRFS_CACHE_FINISHED;
-			add_new_free_space(cache, found_key.objectid,
-					   found_key.objectid +
-					   found_key.offset);
-			btrfs_free_excluded_extents(cache);
-		}
-
-		ret = btrfs_add_block_group_cache(info, cache);
-		if (ret) {
-			btrfs_remove_free_space_cache(cache);
-			btrfs_put_block_group(cache);
-			goto error;
-		}
-
-		trace_btrfs_add_block_group(info, cache, 0);
-		btrfs_update_space_info(info, cache->flags, found_key.offset,
-					btrfs_block_group_used(&cache->item),
-					cache->bytes_super, &space_info);
-
-		cache->space_info = space_info;
-
-		link_block_group(cache);
-
-		set_avail_alloc_bits(info, cache->flags);
-		if (btrfs_chunk_readonly(info, cache->key.objectid)) {
-			__btrfs_inc_block_group_ro(cache, 1);
-		} else if (btrfs_block_group_used(&cache->item) == 0) {
-			ASSERT(list_empty(&cache->bg_list));
-			btrfs_mark_bg_unused(cache);
-		}
-	}
-
-	list_for_each_entry_rcu(space_info, &info->space_info, list) {
-		if (!(btrfs_get_alloc_profile(info, space_info->flags) &
-		      (BTRFS_BLOCK_GROUP_RAID10 |
-		       BTRFS_BLOCK_GROUP_RAID1 |
-		       BTRFS_BLOCK_GROUP_RAID5 |
-		       BTRFS_BLOCK_GROUP_RAID6 |
-		       BTRFS_BLOCK_GROUP_DUP)))
-			continue;
-		/*
-		 * avoid allocating from un-mirrored block group if there are
-		 * mirrored block groups.
-		 */
-		list_for_each_entry(cache,
-				&space_info->block_groups[BTRFS_RAID_RAID0],
-				list)
-			__btrfs_inc_block_group_ro(cache, 1);
-		list_for_each_entry(cache,
-				&space_info->block_groups[BTRFS_RAID_SINGLE],
-				list)
-			__btrfs_inc_block_group_ro(cache, 1);
-	}
-
-	btrfs_add_raid_kobjects(info);
-	btrfs_init_global_block_rsv(info);
-	ret = check_chunk_block_group_mappings(info);
-error:
-	btrfs_free_path(path);
-	return ret;
-}
-
-void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_root *extent_root = fs_info->extent_root;
-	struct btrfs_block_group_item item;
-	struct btrfs_key key;
-	int ret = 0;
-
-	if (!trans->can_flush_pending_bgs)
-		return;
-
-	while (!list_empty(&trans->new_bgs)) {
-		block_group = list_first_entry(&trans->new_bgs,
-					       struct btrfs_block_group_cache,
-					       bg_list);
-		if (ret)
-			goto next;
-
-		spin_lock(&block_group->lock);
-		memcpy(&item, &block_group->item, sizeof(item));
-		memcpy(&key, &block_group->key, sizeof(key));
-		spin_unlock(&block_group->lock);
-
-		ret = btrfs_insert_item(trans, extent_root, &key, &item,
-					sizeof(item));
-		if (ret)
-			btrfs_abort_transaction(trans, ret);
-		ret = btrfs_finish_chunk_alloc(trans, key.objectid, key.offset);
-		if (ret)
-			btrfs_abort_transaction(trans, ret);
-		add_block_group_free_space(trans, block_group);
-		/* already aborted the transaction if it failed. */
-next:
-		btrfs_delayed_refs_rsv_release(fs_info, 1);
-		list_del_init(&block_group->bg_list);
-	}
-	btrfs_trans_release_chunk_metadata(trans);
-}
-
-int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
-			   u64 type, u64 chunk_offset, u64 size)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_block_group_cache *cache;
-	int ret;
-
-	btrfs_set_log_full_commit(trans);
-
-	cache = btrfs_create_block_group_cache(fs_info, chunk_offset, size);
-	if (!cache)
-		return -ENOMEM;
-
-	btrfs_set_block_group_used(&cache->item, bytes_used);
-	btrfs_set_block_group_chunk_objectid(&cache->item,
-					     BTRFS_FIRST_CHUNK_TREE_OBJECTID);
-	btrfs_set_block_group_flags(&cache->item, type);
-
-	cache->flags = type;
-	cache->last_byte_to_unpin = (u64)-1;
-	cache->cached = BTRFS_CACHE_FINISHED;
-	cache->needs_free_space = 1;
-	ret = exclude_super_stripes(cache);
-	if (ret) {
-		/*
-		 * We may have excluded something, so call this just in
-		 * case.
-		 */
-		btrfs_free_excluded_extents(cache);
-		btrfs_put_block_group(cache);
-		return ret;
-	}
-
-	add_new_free_space(cache, chunk_offset, chunk_offset + size);
-
-	btrfs_free_excluded_extents(cache);
-
-#ifdef CONFIG_BTRFS_DEBUG
-	if (btrfs_should_fragment_free_space(cache)) {
-		u64 new_bytes_used = size - bytes_used;
-
-		bytes_used += new_bytes_used >> 1;
-		btrfs_fragment_free_space(cache);
-	}
-#endif
-	/*
-	 * Ensure the corresponding space_info object is created and
-	 * assigned to our block group. We want our bg to be added to the rbtree
-	 * with its ->space_info set.
-	 */
-	cache->space_info = btrfs_find_space_info(fs_info, cache->flags);
-	ASSERT(cache->space_info);
-
-	ret = btrfs_add_block_group_cache(fs_info, cache);
-	if (ret) {
-		btrfs_remove_free_space_cache(cache);
-		btrfs_put_block_group(cache);
-		return ret;
-	}
-
-	/*
-	 * Now that our block group has its ->space_info set and is inserted in
-	 * the rbtree, update the space info's counters.
-	 */
-	trace_btrfs_add_block_group(fs_info, cache, 1);
-	btrfs_update_space_info(fs_info, cache->flags, size, bytes_used,
-				cache->bytes_super, &cache->space_info);
-	btrfs_update_global_block_rsv(fs_info);
-
-	link_block_group(cache);
-
-	list_add_tail(&cache->bg_list, &trans->new_bgs);
-	trans->delayed_ref_updates++;
-	btrfs_update_delayed_refs_rsv(trans);
-
-	set_avail_alloc_bits(fs_info, type);
-	return 0;
-}
-
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
 				   u64 start, u64 end)
 {
-- 
2.14.3

[PATCH 16/25] btrfs: temporarily export btrfs_get_restripe_target

[Josef Bacik]

This gets used by a few different logical chunks of the block group
code, export it while we move things around.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.h | 2 ++
 fs/btrfs/extent-tree.c | 8 ++++----
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index f38e726c8740..4ea744e29c1c 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -202,4 +202,6 @@ btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
 
 int __btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache,
 			       int force);
+u64 btrfs_get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags);
+
 #endif /* BTRFS_BLOCK_GROUP_H */
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index acb25ea7dbd0..f6e2cbe383dd 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3048,7 +3048,7 @@ int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
  *
  * should be called with balance_lock held
  */
-static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
+u64 btrfs_get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
 {
 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
 	u64 target = 0;
@@ -3089,7 +3089,7 @@ static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
 	 * try to reduce to the target profile
 	 */
 	spin_lock(&fs_info->balance_lock);
-	target = get_restripe_target(fs_info, flags);
+	target = btrfs_get_restripe_target(fs_info, flags);
 	if (target) {
 		/* pick target profile only if it's already available */
 		if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
@@ -6533,7 +6533,7 @@ static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
 	 * if restripe for this chunk_type is on pick target profile and
 	 * return, otherwise do the usual balance
 	 */
-	stripped = get_restripe_target(fs_info, flags);
+	stripped = btrfs_get_restripe_target(fs_info, flags);
 	if (stripped)
 		return extended_to_chunk(stripped);
 
@@ -6839,7 +6839,7 @@ int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr)
 	 *      3: raid0
 	 *      4: single
 	 */
-	target = get_restripe_target(fs_info, block_group->flags);
+	target = btrfs_get_restripe_target(fs_info, block_group->flags);
 	if (target) {
 		index = btrfs_bg_flags_to_raid_index(extended_to_chunk(target));
 	} else {
-- 
2.14.3

[PATCH 17/25] btrfs: migrate inc/dec_block_group_ro code

[Josef Bacik]

This can easily be moved now.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 196 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |   2 +
 fs/btrfs/ctree.h       |   2 -
 fs/btrfs/extent-tree.c | 196 -------------------------------------------------
 4 files changed, 198 insertions(+), 198 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index de9ebbcd971a..cc69a6a14bc9 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1789,3 +1789,199 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 	set_avail_alloc_bits(fs_info, type);
 	return 0;
 }
+
+static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	u64 num_devices;
+	u64 stripped;
+
+	/*
+	 * if restripe for this chunk_type is on pick target profile and
+	 * return, otherwise do the usual balance
+	 */
+	stripped = btrfs_get_restripe_target(fs_info, flags);
+	if (stripped)
+		return extended_to_chunk(stripped);
+
+	num_devices = fs_info->fs_devices->rw_devices;
+
+	stripped = BTRFS_BLOCK_GROUP_RAID0 |
+		BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
+		BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
+
+	if (num_devices == 1) {
+		stripped |= BTRFS_BLOCK_GROUP_DUP;
+		stripped = flags & ~stripped;
+
+		/* turn raid0 into single device chunks */
+		if (flags & BTRFS_BLOCK_GROUP_RAID0)
+			return stripped;
+
+		/* turn mirroring into duplication */
+		if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
+			     BTRFS_BLOCK_GROUP_RAID10))
+			return stripped | BTRFS_BLOCK_GROUP_DUP;
+	} else {
+		/* they already had raid on here, just return */
+		if (flags & stripped)
+			return flags;
+
+		stripped |= BTRFS_BLOCK_GROUP_DUP;
+		stripped = flags & ~stripped;
+
+		/* switch duplicated blocks with raid1 */
+		if (flags & BTRFS_BLOCK_GROUP_DUP)
+			return stripped | BTRFS_BLOCK_GROUP_RAID1;
+
+		/* this is drive concat, leave it alone */
+	}
+
+	return flags;
+}
+
+int __btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache,
+			       int force)
+{
+	struct btrfs_space_info *sinfo = cache->space_info;
+	u64 num_bytes;
+	u64 sinfo_used;
+	u64 min_allocable_bytes;
+	int ret = -ENOSPC;
+
+	/*
+	 * We need some metadata space and system metadata space for
+	 * allocating chunks in some corner cases until we force to set
+	 * it to be readonly.
+	 */
+	if ((sinfo->flags &
+	     (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
+	    !force)
+		min_allocable_bytes = SZ_1M;
+	else
+		min_allocable_bytes = 0;
+
+	spin_lock(&sinfo->lock);
+	spin_lock(&cache->lock);
+
+	if (cache->ro) {
+		cache->ro++;
+		ret = 0;
+		goto out;
+	}
+
+	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
+		    cache->bytes_super - btrfs_block_group_used(&cache->item);
+	sinfo_used = btrfs_space_info_used(sinfo, true);
+
+	if (sinfo_used + num_bytes + min_allocable_bytes <=
+	    sinfo->total_bytes) {
+		sinfo->bytes_readonly += num_bytes;
+		cache->ro++;
+		list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
+		ret = 0;
+	}
+out:
+	spin_unlock(&cache->lock);
+	spin_unlock(&sinfo->lock);
+	if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) {
+		btrfs_info(cache->fs_info,
+			"unable to make block group %llu ro",
+			cache->key.objectid);
+		btrfs_info(cache->fs_info,
+			"sinfo_used=%llu bg_num_bytes=%llu min_allocable=%llu",
+			sinfo_used, num_bytes, min_allocable_bytes);
+		btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0);
+	}
+	return ret;
+}
+
+int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
+
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct btrfs_trans_handle *trans;
+	u64 alloc_flags;
+	int ret;
+
+again:
+	trans = btrfs_join_transaction(fs_info->extent_root);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+
+	/*
+	 * we're not allowed to set block groups readonly after the dirty
+	 * block groups cache has started writing.  If it already started,
+	 * back off and let this transaction commit
+	 */
+	mutex_lock(&fs_info->ro_block_group_mutex);
+	if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) {
+		u64 transid = trans->transid;
+
+		mutex_unlock(&fs_info->ro_block_group_mutex);
+		btrfs_end_transaction(trans);
+
+		ret = btrfs_wait_for_commit(fs_info, transid);
+		if (ret)
+			return ret;
+		goto again;
+	}
+
+	/*
+	 * if we are changing raid levels, try to allocate a corresponding
+	 * block group with the new raid level.
+	 */
+	alloc_flags = update_block_group_flags(fs_info, cache->flags);
+	if (alloc_flags != cache->flags) {
+		ret = btrfs_chunk_alloc(trans, alloc_flags,
+					CHUNK_ALLOC_FORCE);
+		/*
+		 * ENOSPC is allowed here, we may have enough space
+		 * already allocated at the new raid level to
+		 * carry on
+		 */
+		if (ret == -ENOSPC)
+			ret = 0;
+		if (ret < 0)
+			goto out;
+	}
+
+	ret = __btrfs_inc_block_group_ro(cache, 0);
+	if (!ret)
+		goto out;
+	alloc_flags = btrfs_get_alloc_profile(fs_info, cache->space_info->flags);
+	ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
+	if (ret < 0)
+		goto out;
+	ret = __btrfs_inc_block_group_ro(cache, 0);
+out:
+	if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
+		alloc_flags = update_block_group_flags(fs_info, cache->flags);
+		mutex_lock(&fs_info->chunk_mutex);
+		check_system_chunk(trans, alloc_flags);
+		mutex_unlock(&fs_info->chunk_mutex);
+	}
+	mutex_unlock(&fs_info->ro_block_group_mutex);
+
+	btrfs_end_transaction(trans);
+	return ret;
+}
+
+void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_space_info *sinfo = cache->space_info;
+	u64 num_bytes;
+
+	BUG_ON(!cache->ro);
+
+	spin_lock(&sinfo->lock);
+	spin_lock(&cache->lock);
+	if (!--cache->ro) {
+		num_bytes = cache->key.offset - cache->reserved -
+			    cache->pinned - cache->bytes_super -
+			    btrfs_block_group_used(&cache->item);
+		sinfo->bytes_readonly -= num_bytes;
+		list_del_init(&cache->ro_list);
+	}
+	spin_unlock(&cache->lock);
+	spin_unlock(&sinfo->lock);
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 4ea744e29c1c..bccf2b02908a 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -191,6 +191,8 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
 			   u64 bytes_used, u64 type, u64 chunk_offset,
 			   u64 size);
 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
+int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache);
+void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache);
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e36c949a25c7..b609ec239cc7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2586,8 +2586,6 @@ void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes,
 				    bool qgroup_free);
 
 int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes);
-int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache);
-void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f6e2cbe383dd..129bc04fcffd 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -6524,182 +6524,6 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 num_devices;
-	u64 stripped;
-
-	/*
-	 * if restripe for this chunk_type is on pick target profile and
-	 * return, otherwise do the usual balance
-	 */
-	stripped = btrfs_get_restripe_target(fs_info, flags);
-	if (stripped)
-		return extended_to_chunk(stripped);
-
-	num_devices = fs_info->fs_devices->rw_devices;
-
-	stripped = BTRFS_BLOCK_GROUP_RAID0 |
-		BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
-		BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
-
-	if (num_devices == 1) {
-		stripped |= BTRFS_BLOCK_GROUP_DUP;
-		stripped = flags & ~stripped;
-
-		/* turn raid0 into single device chunks */
-		if (flags & BTRFS_BLOCK_GROUP_RAID0)
-			return stripped;
-
-		/* turn mirroring into duplication */
-		if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
-			     BTRFS_BLOCK_GROUP_RAID10))
-			return stripped | BTRFS_BLOCK_GROUP_DUP;
-	} else {
-		/* they already had raid on here, just return */
-		if (flags & stripped)
-			return flags;
-
-		stripped |= BTRFS_BLOCK_GROUP_DUP;
-		stripped = flags & ~stripped;
-
-		/* switch duplicated blocks with raid1 */
-		if (flags & BTRFS_BLOCK_GROUP_DUP)
-			return stripped | BTRFS_BLOCK_GROUP_RAID1;
-
-		/* this is drive concat, leave it alone */
-	}
-
-	return flags;
-}
-
-int __btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache,
-			       int force)
-{
-	struct btrfs_space_info *sinfo = cache->space_info;
-	u64 num_bytes;
-	u64 sinfo_used;
-	u64 min_allocable_bytes;
-	int ret = -ENOSPC;
-
-	/*
-	 * We need some metadata space and system metadata space for
-	 * allocating chunks in some corner cases until we force to set
-	 * it to be readonly.
-	 */
-	if ((sinfo->flags &
-	     (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
-	    !force)
-		min_allocable_bytes = SZ_1M;
-	else
-		min_allocable_bytes = 0;
-
-	spin_lock(&sinfo->lock);
-	spin_lock(&cache->lock);
-
-	if (cache->ro) {
-		cache->ro++;
-		ret = 0;
-		goto out;
-	}
-
-	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
-		    cache->bytes_super - btrfs_block_group_used(&cache->item);
-	sinfo_used = btrfs_space_info_used(sinfo, true);
-
-	if (sinfo_used + num_bytes + min_allocable_bytes <=
-	    sinfo->total_bytes) {
-		sinfo->bytes_readonly += num_bytes;
-		cache->ro++;
-		list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
-		ret = 0;
-	}
-out:
-	spin_unlock(&cache->lock);
-	spin_unlock(&sinfo->lock);
-	if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) {
-		btrfs_info(cache->fs_info,
-			"unable to make block group %llu ro",
-			cache->key.objectid);
-		btrfs_info(cache->fs_info,
-			"sinfo_used=%llu bg_num_bytes=%llu min_allocable=%llu",
-			sinfo_used, num_bytes, min_allocable_bytes);
-		btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0);
-	}
-	return ret;
-}
-
-int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
-
-{
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	struct btrfs_trans_handle *trans;
-	u64 alloc_flags;
-	int ret;
-
-again:
-	trans = btrfs_join_transaction(fs_info->extent_root);
-	if (IS_ERR(trans))
-		return PTR_ERR(trans);
-
-	/*
-	 * we're not allowed to set block groups readonly after the dirty
-	 * block groups cache has started writing.  If it already started,
-	 * back off and let this transaction commit
-	 */
-	mutex_lock(&fs_info->ro_block_group_mutex);
-	if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) {
-		u64 transid = trans->transid;
-
-		mutex_unlock(&fs_info->ro_block_group_mutex);
-		btrfs_end_transaction(trans);
-
-		ret = btrfs_wait_for_commit(fs_info, transid);
-		if (ret)
-			return ret;
-		goto again;
-	}
-
-	/*
-	 * if we are changing raid levels, try to allocate a corresponding
-	 * block group with the new raid level.
-	 */
-	alloc_flags = update_block_group_flags(fs_info, cache->flags);
-	if (alloc_flags != cache->flags) {
-		ret = btrfs_chunk_alloc(trans, alloc_flags,
-					CHUNK_ALLOC_FORCE);
-		/*
-		 * ENOSPC is allowed here, we may have enough space
-		 * already allocated at the new raid level to
-		 * carry on
-		 */
-		if (ret == -ENOSPC)
-			ret = 0;
-		if (ret < 0)
-			goto out;
-	}
-
-	ret = __btrfs_inc_block_group_ro(cache, 0);
-	if (!ret)
-		goto out;
-	alloc_flags = btrfs_get_alloc_profile(fs_info, cache->space_info->flags);
-	ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
-	if (ret < 0)
-		goto out;
-	ret = __btrfs_inc_block_group_ro(cache, 0);
-out:
-	if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
-		alloc_flags = update_block_group_flags(fs_info, cache->flags);
-		mutex_lock(&fs_info->chunk_mutex);
-		check_system_chunk(trans, alloc_flags);
-		mutex_unlock(&fs_info->chunk_mutex);
-	}
-	mutex_unlock(&fs_info->ro_block_group_mutex);
-
-	btrfs_end_transaction(trans);
-	return ret;
-}
-
 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type)
 {
 	u64 alloc_flags = btrfs_get_alloc_profile(trans->fs_info, type);
@@ -6742,26 +6566,6 @@ u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
 	return free_bytes;
 }
 
-void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_space_info *sinfo = cache->space_info;
-	u64 num_bytes;
-
-	BUG_ON(!cache->ro);
-
-	spin_lock(&sinfo->lock);
-	spin_lock(&cache->lock);
-	if (!--cache->ro) {
-		num_bytes = cache->key.offset - cache->reserved -
-			    cache->pinned - cache->bytes_super -
-			    btrfs_block_group_used(&cache->item);
-		sinfo->bytes_readonly -= num_bytes;
-		list_del_init(&cache->ro_list);
-	}
-	spin_unlock(&cache->lock);
-	spin_unlock(&sinfo->lock);
-}
-
 /*
  * Checks to see if it's even possible to relocate this block group.
  *
-- 
2.14.3

[PATCH 18/25] btrfs: migrate the dirty bg writeout code

[Josef Bacik]

This can be easily migrated over now.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 520 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |   3 +
 fs/btrfs/ctree.h       |   3 -
 fs/btrfs/extent-tree.c | 518 ------------------------------------------------
 4 files changed, 523 insertions(+), 521 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index cc69a6a14bc9..540dc7219f48 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -14,6 +14,7 @@
 #include "ref-verify.h"
 #include "sysfs.h"
 #include "tree-log.h"
+#include "delalloc-space.h"
 
 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
 {
@@ -1985,3 +1986,522 @@ void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache)
 	spin_unlock(&cache->lock);
 	spin_unlock(&sinfo->lock);
 }
+
+static int write_one_cache_group(struct btrfs_trans_handle *trans,
+				 struct btrfs_path *path,
+				 struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	int ret;
+	struct btrfs_root *extent_root = fs_info->extent_root;
+	unsigned long bi;
+	struct extent_buffer *leaf;
+
+	ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
+	if (ret) {
+		if (ret > 0)
+			ret = -ENOENT;
+		goto fail;
+	}
+
+	leaf = path->nodes[0];
+	bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
+	write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
+	btrfs_mark_buffer_dirty(leaf);
+fail:
+	btrfs_release_path(path);
+	return ret;
+
+}
+
+static int cache_save_setup(struct btrfs_block_group_cache *block_group,
+			    struct btrfs_trans_handle *trans,
+			    struct btrfs_path *path)
+{
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
+	struct btrfs_root *root = fs_info->tree_root;
+	struct inode *inode = NULL;
+	struct extent_changeset *data_reserved = NULL;
+	u64 alloc_hint = 0;
+	int dcs = BTRFS_DC_ERROR;
+	u64 num_pages = 0;
+	int retries = 0;
+	int ret = 0;
+
+	/*
+	 * If this block group is smaller than 100 megs don't bother caching the
+	 * block group.
+	 */
+	if (block_group->key.offset < (100 * SZ_1M)) {
+		spin_lock(&block_group->lock);
+		block_group->disk_cache_state = BTRFS_DC_WRITTEN;
+		spin_unlock(&block_group->lock);
+		return 0;
+	}
+
+	if (trans->aborted)
+		return 0;
+again:
+	inode = lookup_free_space_inode(block_group, path);
+	if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
+		ret = PTR_ERR(inode);
+		btrfs_release_path(path);
+		goto out;
+	}
+
+	if (IS_ERR(inode)) {
+		BUG_ON(retries);
+		retries++;
+
+		if (block_group->ro)
+			goto out_free;
+
+		ret = create_free_space_inode(trans, block_group, path);
+		if (ret)
+			goto out_free;
+		goto again;
+	}
+
+	/*
+	 * We want to set the generation to 0, that way if anything goes wrong
+	 * from here on out we know not to trust this cache when we load up next
+	 * time.
+	 */
+	BTRFS_I(inode)->generation = 0;
+	ret = btrfs_update_inode(trans, root, inode);
+	if (ret) {
+		/*
+		 * So theoretically we could recover from this, simply set the
+		 * super cache generation to 0 so we know to invalidate the
+		 * cache, but then we'd have to keep track of the block groups
+		 * that fail this way so we know we _have_ to reset this cache
+		 * before the next commit or risk reading stale cache.  So to
+		 * limit our exposure to horrible edge cases lets just abort the
+		 * transaction, this only happens in really bad situations
+		 * anyway.
+		 */
+		btrfs_abort_transaction(trans, ret);
+		goto out_put;
+	}
+	WARN_ON(ret);
+
+	/* We've already setup this transaction, go ahead and exit */
+	if (block_group->cache_generation == trans->transid &&
+	    i_size_read(inode)) {
+		dcs = BTRFS_DC_SETUP;
+		goto out_put;
+	}
+
+	if (i_size_read(inode) > 0) {
+		ret = btrfs_check_trunc_cache_free_space(fs_info,
+					&fs_info->global_block_rsv);
+		if (ret)
+			goto out_put;
+
+		ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
+		if (ret)
+			goto out_put;
+	}
+
+	spin_lock(&block_group->lock);
+	if (block_group->cached != BTRFS_CACHE_FINISHED ||
+	    !btrfs_test_opt(fs_info, SPACE_CACHE)) {
+		/*
+		 * don't bother trying to write stuff out _if_
+		 * a) we're not cached,
+		 * b) we're with nospace_cache mount option,
+		 * c) we're with v2 space_cache (FREE_SPACE_TREE).
+		 */
+		dcs = BTRFS_DC_WRITTEN;
+		spin_unlock(&block_group->lock);
+		goto out_put;
+	}
+	spin_unlock(&block_group->lock);
+
+	/*
+	 * We hit an ENOSPC when setting up the cache in this transaction, just
+	 * skip doing the setup, we've already cleared the cache so we're safe.
+	 */
+	if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) {
+		ret = -ENOSPC;
+		goto out_put;
+	}
+
+	/*
+	 * Try to preallocate enough space based on how big the block group is.
+	 * Keep in mind this has to include any pinned space which could end up
+	 * taking up quite a bit since it's not folded into the other space
+	 * cache.
+	 */
+	num_pages = div_u64(block_group->key.offset, SZ_256M);
+	if (!num_pages)
+		num_pages = 1;
+
+	num_pages *= 16;
+	num_pages *= PAGE_SIZE;
+
+	ret = btrfs_check_data_free_space(inode, &data_reserved, 0, num_pages);
+	if (ret)
+		goto out_put;
+
+	ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
+					      num_pages, num_pages,
+					      &alloc_hint);
+	/*
+	 * Our cache requires contiguous chunks so that we don't modify a bunch
+	 * of metadata or split extents when writing the cache out, which means
+	 * we can enospc if we are heavily fragmented in addition to just normal
+	 * out of space conditions.  So if we hit this just skip setting up any
+	 * other block groups for this transaction, maybe we'll unpin enough
+	 * space the next time around.
+	 */
+	if (!ret)
+		dcs = BTRFS_DC_SETUP;
+	else if (ret == -ENOSPC)
+		set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags);
+
+out_put:
+	iput(inode);
+out_free:
+	btrfs_release_path(path);
+out:
+	spin_lock(&block_group->lock);
+	if (!ret && dcs == BTRFS_DC_SETUP)
+		block_group->cache_generation = trans->transid;
+	block_group->disk_cache_state = dcs;
+	spin_unlock(&block_group->lock);
+
+	extent_changeset_free(data_reserved);
+	return ret;
+}
+
+int btrfs_setup_space_cache(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *cache, *tmp;
+	struct btrfs_transaction *cur_trans = trans->transaction;
+	struct btrfs_path *path;
+
+	if (list_empty(&cur_trans->dirty_bgs) ||
+	    !btrfs_test_opt(fs_info, SPACE_CACHE))
+		return 0;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	/* Could add new block groups, use _safe just in case */
+	list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
+				 dirty_list) {
+		if (cache->disk_cache_state == BTRFS_DC_CLEAR)
+			cache_save_setup(cache, trans, path);
+	}
+
+	btrfs_free_path(path);
+	return 0;
+}
+
+/*
+ * transaction commit does final block group cache writeback during a
+ * critical section where nothing is allowed to change the FS.  This is
+ * required in order for the cache to actually match the block group,
+ * but can introduce a lot of latency into the commit.
+ *
+ * So, btrfs_start_dirty_block_groups is here to kick off block group
+ * cache IO.  There's a chance we'll have to redo some of it if the
+ * block group changes again during the commit, but it greatly reduces
+ * the commit latency by getting rid of the easy block groups while
+ * we're still allowing others to join the commit.
+ */
+int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *cache;
+	struct btrfs_transaction *cur_trans = trans->transaction;
+	int ret = 0;
+	int should_put;
+	struct btrfs_path *path = NULL;
+	LIST_HEAD(dirty);
+	struct list_head *io = &cur_trans->io_bgs;
+	int num_started = 0;
+	int loops = 0;
+
+	spin_lock(&cur_trans->dirty_bgs_lock);
+	if (list_empty(&cur_trans->dirty_bgs)) {
+		spin_unlock(&cur_trans->dirty_bgs_lock);
+		return 0;
+	}
+	list_splice_init(&cur_trans->dirty_bgs, &dirty);
+	spin_unlock(&cur_trans->dirty_bgs_lock);
+
+again:
+	/*
+	 * make sure all the block groups on our dirty list actually
+	 * exist
+	 */
+	btrfs_create_pending_block_groups(trans);
+
+	if (!path) {
+		path = btrfs_alloc_path();
+		if (!path)
+			return -ENOMEM;
+	}
+
+	/*
+	 * cache_write_mutex is here only to save us from balance or automatic
+	 * removal of empty block groups deleting this block group while we are
+	 * writing out the cache
+	 */
+	mutex_lock(&trans->transaction->cache_write_mutex);
+	while (!list_empty(&dirty)) {
+		bool drop_reserve = true;
+
+		cache = list_first_entry(&dirty,
+					 struct btrfs_block_group_cache,
+					 dirty_list);
+		/*
+		 * this can happen if something re-dirties a block
+		 * group that is already under IO.  Just wait for it to
+		 * finish and then do it all again
+		 */
+		if (!list_empty(&cache->io_list)) {
+			list_del_init(&cache->io_list);
+			btrfs_wait_cache_io(trans, cache, path);
+			btrfs_put_block_group(cache);
+		}
+
+
+		/*
+		 * btrfs_wait_cache_io uses the cache->dirty_list to decide
+		 * if it should update the cache_state.  Don't delete
+		 * until after we wait.
+		 *
+		 * Since we're not running in the commit critical section
+		 * we need the dirty_bgs_lock to protect from update_block_group
+		 */
+		spin_lock(&cur_trans->dirty_bgs_lock);
+		list_del_init(&cache->dirty_list);
+		spin_unlock(&cur_trans->dirty_bgs_lock);
+
+		should_put = 1;
+
+		cache_save_setup(cache, trans, path);
+
+		if (cache->disk_cache_state == BTRFS_DC_SETUP) {
+			cache->io_ctl.inode = NULL;
+			ret = btrfs_write_out_cache(trans, cache, path);
+			if (ret == 0 && cache->io_ctl.inode) {
+				num_started++;
+				should_put = 0;
+
+				/*
+				 * The cache_write_mutex is protecting the
+				 * io_list, also refer to the definition of
+				 * btrfs_transaction::io_bgs for more details
+				 */
+				list_add_tail(&cache->io_list, io);
+			} else {
+				/*
+				 * if we failed to write the cache, the
+				 * generation will be bad and life goes on
+				 */
+				ret = 0;
+			}
+		}
+		if (!ret) {
+			ret = write_one_cache_group(trans, path, cache);
+			/*
+			 * Our block group might still be attached to the list
+			 * of new block groups in the transaction handle of some
+			 * other task (struct btrfs_trans_handle->new_bgs). This
+			 * means its block group item isn't yet in the extent
+			 * tree. If this happens ignore the error, as we will
+			 * try again later in the critical section of the
+			 * transaction commit.
+			 */
+			if (ret == -ENOENT) {
+				ret = 0;
+				spin_lock(&cur_trans->dirty_bgs_lock);
+				if (list_empty(&cache->dirty_list)) {
+					list_add_tail(&cache->dirty_list,
+						      &cur_trans->dirty_bgs);
+					btrfs_get_block_group(cache);
+					drop_reserve = false;
+				}
+				spin_unlock(&cur_trans->dirty_bgs_lock);
+			} else if (ret) {
+				btrfs_abort_transaction(trans, ret);
+			}
+		}
+
+		/* if it's not on the io list, we need to put the block group */
+		if (should_put)
+			btrfs_put_block_group(cache);
+		if (drop_reserve)
+			btrfs_delayed_refs_rsv_release(fs_info, 1);
+
+		if (ret)
+			break;
+
+		/*
+		 * Avoid blocking other tasks for too long. It might even save
+		 * us from writing caches for block groups that are going to be
+		 * removed.
+		 */
+		mutex_unlock(&trans->transaction->cache_write_mutex);
+		mutex_lock(&trans->transaction->cache_write_mutex);
+	}
+	mutex_unlock(&trans->transaction->cache_write_mutex);
+
+	/*
+	 * go through delayed refs for all the stuff we've just kicked off
+	 * and then loop back (just once)
+	 */
+	ret = btrfs_run_delayed_refs(trans, 0);
+	if (!ret && loops == 0) {
+		loops++;
+		spin_lock(&cur_trans->dirty_bgs_lock);
+		list_splice_init(&cur_trans->dirty_bgs, &dirty);
+		/*
+		 * dirty_bgs_lock protects us from concurrent block group
+		 * deletes too (not just cache_write_mutex).
+		 */
+		if (!list_empty(&dirty)) {
+			spin_unlock(&cur_trans->dirty_bgs_lock);
+			goto again;
+		}
+		spin_unlock(&cur_trans->dirty_bgs_lock);
+	} else if (ret < 0) {
+		btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
+	}
+
+	btrfs_free_path(path);
+	return ret;
+}
+
+int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *cache;
+	struct btrfs_transaction *cur_trans = trans->transaction;
+	int ret = 0;
+	int should_put;
+	struct btrfs_path *path;
+	struct list_head *io = &cur_trans->io_bgs;
+	int num_started = 0;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	/*
+	 * Even though we are in the critical section of the transaction commit,
+	 * we can still have concurrent tasks adding elements to this
+	 * transaction's list of dirty block groups. These tasks correspond to
+	 * endio free space workers started when writeback finishes for a
+	 * space cache, which run inode.c:btrfs_finish_ordered_io(), and can
+	 * allocate new block groups as a result of COWing nodes of the root
+	 * tree when updating the free space inode. The writeback for the space
+	 * caches is triggered by an earlier call to
+	 * btrfs_start_dirty_block_groups() and iterations of the following
+	 * loop.
+	 * Also we want to do the cache_save_setup first and then run the
+	 * delayed refs to make sure we have the best chance at doing this all
+	 * in one shot.
+	 */
+	spin_lock(&cur_trans->dirty_bgs_lock);
+	while (!list_empty(&cur_trans->dirty_bgs)) {
+		cache = list_first_entry(&cur_trans->dirty_bgs,
+					 struct btrfs_block_group_cache,
+					 dirty_list);
+
+		/*
+		 * this can happen if cache_save_setup re-dirties a block
+		 * group that is already under IO.  Just wait for it to
+		 * finish and then do it all again
+		 */
+		if (!list_empty(&cache->io_list)) {
+			spin_unlock(&cur_trans->dirty_bgs_lock);
+			list_del_init(&cache->io_list);
+			btrfs_wait_cache_io(trans, cache, path);
+			btrfs_put_block_group(cache);
+			spin_lock(&cur_trans->dirty_bgs_lock);
+		}
+
+		/*
+		 * don't remove from the dirty list until after we've waited
+		 * on any pending IO
+		 */
+		list_del_init(&cache->dirty_list);
+		spin_unlock(&cur_trans->dirty_bgs_lock);
+		should_put = 1;
+
+		cache_save_setup(cache, trans, path);
+
+		if (!ret)
+			ret = btrfs_run_delayed_refs(trans,
+						     (unsigned long) -1);
+
+		if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
+			cache->io_ctl.inode = NULL;
+			ret = btrfs_write_out_cache(trans, cache, path);
+			if (ret == 0 && cache->io_ctl.inode) {
+				num_started++;
+				should_put = 0;
+				list_add_tail(&cache->io_list, io);
+			} else {
+				/*
+				 * if we failed to write the cache, the
+				 * generation will be bad and life goes on
+				 */
+				ret = 0;
+			}
+		}
+		if (!ret) {
+			ret = write_one_cache_group(trans, path, cache);
+			/*
+			 * One of the free space endio workers might have
+			 * created a new block group while updating a free space
+			 * cache's inode (at inode.c:btrfs_finish_ordered_io())
+			 * and hasn't released its transaction handle yet, in
+			 * which case the new block group is still attached to
+			 * its transaction handle and its creation has not
+			 * finished yet (no block group item in the extent tree
+			 * yet, etc). If this is the case, wait for all free
+			 * space endio workers to finish and retry. This is a
+			 * a very rare case so no need for a more efficient and
+			 * complex approach.
+			 */
+			if (ret == -ENOENT) {
+				wait_event(cur_trans->writer_wait,
+				   atomic_read(&cur_trans->num_writers) == 1);
+				ret = write_one_cache_group(trans, path, cache);
+			}
+			if (ret)
+				btrfs_abort_transaction(trans, ret);
+		}
+
+		/* if its not on the io list, we need to put the block group */
+		if (should_put)
+			btrfs_put_block_group(cache);
+		btrfs_delayed_refs_rsv_release(fs_info, 1);
+		spin_lock(&cur_trans->dirty_bgs_lock);
+	}
+	spin_unlock(&cur_trans->dirty_bgs_lock);
+
+	/*
+	 * Refer to the definition of io_bgs member for details why it's safe
+	 * to use it without any locking
+	 */
+	while (!list_empty(io)) {
+		cache = list_first_entry(io, struct btrfs_block_group_cache,
+					 io_list);
+		list_del_init(&cache->io_list);
+		btrfs_wait_cache_io(trans, cache, path);
+		btrfs_put_block_group(cache);
+	}
+
+	btrfs_free_path(path);
+	return ret;
+}
+
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index bccf2b02908a..b093b19696aa 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -193,6 +193,9 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache);
 void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache);
+int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
+int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
+int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b609ec239cc7..15ab2d5f7cd7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2518,9 +2518,6 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans);
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 			 struct btrfs_ref *generic_ref);
 
-int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
-int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
-int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr);
 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 129bc04fcffd..b895380e60b2 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2511,524 +2511,6 @@ int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
 }
 
-static int write_one_cache_group(struct btrfs_trans_handle *trans,
-				 struct btrfs_path *path,
-				 struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	int ret;
-	struct btrfs_root *extent_root = fs_info->extent_root;
-	unsigned long bi;
-	struct extent_buffer *leaf;
-
-	ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
-	if (ret) {
-		if (ret > 0)
-			ret = -ENOENT;
-		goto fail;
-	}
-
-	leaf = path->nodes[0];
-	bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
-	write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
-	btrfs_mark_buffer_dirty(leaf);
-fail:
-	btrfs_release_path(path);
-	return ret;
-
-}
-
-static int cache_save_setup(struct btrfs_block_group_cache *block_group,
-			    struct btrfs_trans_handle *trans,
-			    struct btrfs_path *path)
-{
-	struct btrfs_fs_info *fs_info = block_group->fs_info;
-	struct btrfs_root *root = fs_info->tree_root;
-	struct inode *inode = NULL;
-	struct extent_changeset *data_reserved = NULL;
-	u64 alloc_hint = 0;
-	int dcs = BTRFS_DC_ERROR;
-	u64 num_pages = 0;
-	int retries = 0;
-	int ret = 0;
-
-	/*
-	 * If this block group is smaller than 100 megs don't bother caching the
-	 * block group.
-	 */
-	if (block_group->key.offset < (100 * SZ_1M)) {
-		spin_lock(&block_group->lock);
-		block_group->disk_cache_state = BTRFS_DC_WRITTEN;
-		spin_unlock(&block_group->lock);
-		return 0;
-	}
-
-	if (trans->aborted)
-		return 0;
-again:
-	inode = lookup_free_space_inode(block_group, path);
-	if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
-		ret = PTR_ERR(inode);
-		btrfs_release_path(path);
-		goto out;
-	}
-
-	if (IS_ERR(inode)) {
-		BUG_ON(retries);
-		retries++;
-
-		if (block_group->ro)
-			goto out_free;
-
-		ret = create_free_space_inode(trans, block_group, path);
-		if (ret)
-			goto out_free;
-		goto again;
-	}
-
-	/*
-	 * We want to set the generation to 0, that way if anything goes wrong
-	 * from here on out we know not to trust this cache when we load up next
-	 * time.
-	 */
-	BTRFS_I(inode)->generation = 0;
-	ret = btrfs_update_inode(trans, root, inode);
-	if (ret) {
-		/*
-		 * So theoretically we could recover from this, simply set the
-		 * super cache generation to 0 so we know to invalidate the
-		 * cache, but then we'd have to keep track of the block groups
-		 * that fail this way so we know we _have_ to reset this cache
-		 * before the next commit or risk reading stale cache.  So to
-		 * limit our exposure to horrible edge cases lets just abort the
-		 * transaction, this only happens in really bad situations
-		 * anyway.
-		 */
-		btrfs_abort_transaction(trans, ret);
-		goto out_put;
-	}
-	WARN_ON(ret);
-
-	/* We've already setup this transaction, go ahead and exit */
-	if (block_group->cache_generation == trans->transid &&
-	    i_size_read(inode)) {
-		dcs = BTRFS_DC_SETUP;
-		goto out_put;
-	}
-
-	if (i_size_read(inode) > 0) {
-		ret = btrfs_check_trunc_cache_free_space(fs_info,
-					&fs_info->global_block_rsv);
-		if (ret)
-			goto out_put;
-
-		ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
-		if (ret)
-			goto out_put;
-	}
-
-	spin_lock(&block_group->lock);
-	if (block_group->cached != BTRFS_CACHE_FINISHED ||
-	    !btrfs_test_opt(fs_info, SPACE_CACHE)) {
-		/*
-		 * don't bother trying to write stuff out _if_
-		 * a) we're not cached,
-		 * b) we're with nospace_cache mount option,
-		 * c) we're with v2 space_cache (FREE_SPACE_TREE).
-		 */
-		dcs = BTRFS_DC_WRITTEN;
-		spin_unlock(&block_group->lock);
-		goto out_put;
-	}
-	spin_unlock(&block_group->lock);
-
-	/*
-	 * We hit an ENOSPC when setting up the cache in this transaction, just
-	 * skip doing the setup, we've already cleared the cache so we're safe.
-	 */
-	if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) {
-		ret = -ENOSPC;
-		goto out_put;
-	}
-
-	/*
-	 * Try to preallocate enough space based on how big the block group is.
-	 * Keep in mind this has to include any pinned space which could end up
-	 * taking up quite a bit since it's not folded into the other space
-	 * cache.
-	 */
-	num_pages = div_u64(block_group->key.offset, SZ_256M);
-	if (!num_pages)
-		num_pages = 1;
-
-	num_pages *= 16;
-	num_pages *= PAGE_SIZE;
-
-	ret = btrfs_check_data_free_space(inode, &data_reserved, 0, num_pages);
-	if (ret)
-		goto out_put;
-
-	ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
-					      num_pages, num_pages,
-					      &alloc_hint);
-	/*
-	 * Our cache requires contiguous chunks so that we don't modify a bunch
-	 * of metadata or split extents when writing the cache out, which means
-	 * we can enospc if we are heavily fragmented in addition to just normal
-	 * out of space conditions.  So if we hit this just skip setting up any
-	 * other block groups for this transaction, maybe we'll unpin enough
-	 * space the next time around.
-	 */
-	if (!ret)
-		dcs = BTRFS_DC_SETUP;
-	else if (ret == -ENOSPC)
-		set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags);
-
-out_put:
-	iput(inode);
-out_free:
-	btrfs_release_path(path);
-out:
-	spin_lock(&block_group->lock);
-	if (!ret && dcs == BTRFS_DC_SETUP)
-		block_group->cache_generation = trans->transid;
-	block_group->disk_cache_state = dcs;
-	spin_unlock(&block_group->lock);
-
-	extent_changeset_free(data_reserved);
-	return ret;
-}
-
-int btrfs_setup_space_cache(struct btrfs_trans_handle *trans)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_block_group_cache *cache, *tmp;
-	struct btrfs_transaction *cur_trans = trans->transaction;
-	struct btrfs_path *path;
-
-	if (list_empty(&cur_trans->dirty_bgs) ||
-	    !btrfs_test_opt(fs_info, SPACE_CACHE))
-		return 0;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	/* Could add new block groups, use _safe just in case */
-	list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
-				 dirty_list) {
-		if (cache->disk_cache_state == BTRFS_DC_CLEAR)
-			cache_save_setup(cache, trans, path);
-	}
-
-	btrfs_free_path(path);
-	return 0;
-}
-
-/*
- * transaction commit does final block group cache writeback during a
- * critical section where nothing is allowed to change the FS.  This is
- * required in order for the cache to actually match the block group,
- * but can introduce a lot of latency into the commit.
- *
- * So, btrfs_start_dirty_block_groups is here to kick off block group
- * cache IO.  There's a chance we'll have to redo some of it if the
- * block group changes again during the commit, but it greatly reduces
- * the commit latency by getting rid of the easy block groups while
- * we're still allowing others to join the commit.
- */
-int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_block_group_cache *cache;
-	struct btrfs_transaction *cur_trans = trans->transaction;
-	int ret = 0;
-	int should_put;
-	struct btrfs_path *path = NULL;
-	LIST_HEAD(dirty);
-	struct list_head *io = &cur_trans->io_bgs;
-	int num_started = 0;
-	int loops = 0;
-
-	spin_lock(&cur_trans->dirty_bgs_lock);
-	if (list_empty(&cur_trans->dirty_bgs)) {
-		spin_unlock(&cur_trans->dirty_bgs_lock);
-		return 0;
-	}
-	list_splice_init(&cur_trans->dirty_bgs, &dirty);
-	spin_unlock(&cur_trans->dirty_bgs_lock);
-
-again:
-	/*
-	 * make sure all the block groups on our dirty list actually
-	 * exist
-	 */
-	btrfs_create_pending_block_groups(trans);
-
-	if (!path) {
-		path = btrfs_alloc_path();
-		if (!path)
-			return -ENOMEM;
-	}
-
-	/*
-	 * cache_write_mutex is here only to save us from balance or automatic
-	 * removal of empty block groups deleting this block group while we are
-	 * writing out the cache
-	 */
-	mutex_lock(&trans->transaction->cache_write_mutex);
-	while (!list_empty(&dirty)) {
-		bool drop_reserve = true;
-
-		cache = list_first_entry(&dirty,
-					 struct btrfs_block_group_cache,
-					 dirty_list);
-		/*
-		 * this can happen if something re-dirties a block
-		 * group that is already under IO.  Just wait for it to
-		 * finish and then do it all again
-		 */
-		if (!list_empty(&cache->io_list)) {
-			list_del_init(&cache->io_list);
-			btrfs_wait_cache_io(trans, cache, path);
-			btrfs_put_block_group(cache);
-		}
-
-
-		/*
-		 * btrfs_wait_cache_io uses the cache->dirty_list to decide
-		 * if it should update the cache_state.  Don't delete
-		 * until after we wait.
-		 *
-		 * Since we're not running in the commit critical section
-		 * we need the dirty_bgs_lock to protect from update_block_group
-		 */
-		spin_lock(&cur_trans->dirty_bgs_lock);
-		list_del_init(&cache->dirty_list);
-		spin_unlock(&cur_trans->dirty_bgs_lock);
-
-		should_put = 1;
-
-		cache_save_setup(cache, trans, path);
-
-		if (cache->disk_cache_state == BTRFS_DC_SETUP) {
-			cache->io_ctl.inode = NULL;
-			ret = btrfs_write_out_cache(trans, cache, path);
-			if (ret == 0 && cache->io_ctl.inode) {
-				num_started++;
-				should_put = 0;
-
-				/*
-				 * The cache_write_mutex is protecting the
-				 * io_list, also refer to the definition of
-				 * btrfs_transaction::io_bgs for more details
-				 */
-				list_add_tail(&cache->io_list, io);
-			} else {
-				/*
-				 * if we failed to write the cache, the
-				 * generation will be bad and life goes on
-				 */
-				ret = 0;
-			}
-		}
-		if (!ret) {
-			ret = write_one_cache_group(trans, path, cache);
-			/*
-			 * Our block group might still be attached to the list
-			 * of new block groups in the transaction handle of some
-			 * other task (struct btrfs_trans_handle->new_bgs). This
-			 * means its block group item isn't yet in the extent
-			 * tree. If this happens ignore the error, as we will
-			 * try again later in the critical section of the
-			 * transaction commit.
-			 */
-			if (ret == -ENOENT) {
-				ret = 0;
-				spin_lock(&cur_trans->dirty_bgs_lock);
-				if (list_empty(&cache->dirty_list)) {
-					list_add_tail(&cache->dirty_list,
-						      &cur_trans->dirty_bgs);
-					btrfs_get_block_group(cache);
-					drop_reserve = false;
-				}
-				spin_unlock(&cur_trans->dirty_bgs_lock);
-			} else if (ret) {
-				btrfs_abort_transaction(trans, ret);
-			}
-		}
-
-		/* if it's not on the io list, we need to put the block group */
-		if (should_put)
-			btrfs_put_block_group(cache);
-		if (drop_reserve)
-			btrfs_delayed_refs_rsv_release(fs_info, 1);
-
-		if (ret)
-			break;
-
-		/*
-		 * Avoid blocking other tasks for too long. It might even save
-		 * us from writing caches for block groups that are going to be
-		 * removed.
-		 */
-		mutex_unlock(&trans->transaction->cache_write_mutex);
-		mutex_lock(&trans->transaction->cache_write_mutex);
-	}
-	mutex_unlock(&trans->transaction->cache_write_mutex);
-
-	/*
-	 * go through delayed refs for all the stuff we've just kicked off
-	 * and then loop back (just once)
-	 */
-	ret = btrfs_run_delayed_refs(trans, 0);
-	if (!ret && loops == 0) {
-		loops++;
-		spin_lock(&cur_trans->dirty_bgs_lock);
-		list_splice_init(&cur_trans->dirty_bgs, &dirty);
-		/*
-		 * dirty_bgs_lock protects us from concurrent block group
-		 * deletes too (not just cache_write_mutex).
-		 */
-		if (!list_empty(&dirty)) {
-			spin_unlock(&cur_trans->dirty_bgs_lock);
-			goto again;
-		}
-		spin_unlock(&cur_trans->dirty_bgs_lock);
-	} else if (ret < 0) {
-		btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
-	}
-
-	btrfs_free_path(path);
-	return ret;
-}
-
-int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_block_group_cache *cache;
-	struct btrfs_transaction *cur_trans = trans->transaction;
-	int ret = 0;
-	int should_put;
-	struct btrfs_path *path;
-	struct list_head *io = &cur_trans->io_bgs;
-	int num_started = 0;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	/*
-	 * Even though we are in the critical section of the transaction commit,
-	 * we can still have concurrent tasks adding elements to this
-	 * transaction's list of dirty block groups. These tasks correspond to
-	 * endio free space workers started when writeback finishes for a
-	 * space cache, which run inode.c:btrfs_finish_ordered_io(), and can
-	 * allocate new block groups as a result of COWing nodes of the root
-	 * tree when updating the free space inode. The writeback for the space
-	 * caches is triggered by an earlier call to
-	 * btrfs_start_dirty_block_groups() and iterations of the following
-	 * loop.
-	 * Also we want to do the cache_save_setup first and then run the
-	 * delayed refs to make sure we have the best chance at doing this all
-	 * in one shot.
-	 */
-	spin_lock(&cur_trans->dirty_bgs_lock);
-	while (!list_empty(&cur_trans->dirty_bgs)) {
-		cache = list_first_entry(&cur_trans->dirty_bgs,
-					 struct btrfs_block_group_cache,
-					 dirty_list);
-
-		/*
-		 * this can happen if cache_save_setup re-dirties a block
-		 * group that is already under IO.  Just wait for it to
-		 * finish and then do it all again
-		 */
-		if (!list_empty(&cache->io_list)) {
-			spin_unlock(&cur_trans->dirty_bgs_lock);
-			list_del_init(&cache->io_list);
-			btrfs_wait_cache_io(trans, cache, path);
-			btrfs_put_block_group(cache);
-			spin_lock(&cur_trans->dirty_bgs_lock);
-		}
-
-		/*
-		 * don't remove from the dirty list until after we've waited
-		 * on any pending IO
-		 */
-		list_del_init(&cache->dirty_list);
-		spin_unlock(&cur_trans->dirty_bgs_lock);
-		should_put = 1;
-
-		cache_save_setup(cache, trans, path);
-
-		if (!ret)
-			ret = btrfs_run_delayed_refs(trans,
-						     (unsigned long) -1);
-
-		if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
-			cache->io_ctl.inode = NULL;
-			ret = btrfs_write_out_cache(trans, cache, path);
-			if (ret == 0 && cache->io_ctl.inode) {
-				num_started++;
-				should_put = 0;
-				list_add_tail(&cache->io_list, io);
-			} else {
-				/*
-				 * if we failed to write the cache, the
-				 * generation will be bad and life goes on
-				 */
-				ret = 0;
-			}
-		}
-		if (!ret) {
-			ret = write_one_cache_group(trans, path, cache);
-			/*
-			 * One of the free space endio workers might have
-			 * created a new block group while updating a free space
-			 * cache's inode (at inode.c:btrfs_finish_ordered_io())
-			 * and hasn't released its transaction handle yet, in
-			 * which case the new block group is still attached to
-			 * its transaction handle and its creation has not
-			 * finished yet (no block group item in the extent tree
-			 * yet, etc). If this is the case, wait for all free
-			 * space endio workers to finish and retry. This is a
-			 * a very rare case so no need for a more efficient and
-			 * complex approach.
-			 */
-			if (ret == -ENOENT) {
-				wait_event(cur_trans->writer_wait,
-				   atomic_read(&cur_trans->num_writers) == 1);
-				ret = write_one_cache_group(trans, path, cache);
-			}
-			if (ret)
-				btrfs_abort_transaction(trans, ret);
-		}
-
-		/* if its not on the io list, we need to put the block group */
-		if (should_put)
-			btrfs_put_block_group(cache);
-		btrfs_delayed_refs_rsv_release(fs_info, 1);
-		spin_lock(&cur_trans->dirty_bgs_lock);
-	}
-	spin_unlock(&cur_trans->dirty_bgs_lock);
-
-	/*
-	 * Refer to the definition of io_bgs member for details why it's safe
-	 * to use it without any locking
-	 */
-	while (!list_empty(io)) {
-		cache = list_first_entry(io, struct btrfs_block_group_cache,
-					 io_list);
-		list_del_init(&cache->io_list);
-		btrfs_wait_cache_io(trans, cache, path);
-		btrfs_put_block_group(cache);
-	}
-
-	btrfs_free_path(path);
-	return ret;
-}
-
 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
 {
 	struct btrfs_block_group_cache *block_group;
-- 
2.14.3

[PATCH 19/25] btrfs: export block group accounting helpers

[Josef Bacik]

Want to move these functions into block-group.c, so export them.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.h |  6 ++++++
 fs/btrfs/extent-tree.c | 21 ++++++++++-----------
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index b093b19696aa..3b7516836849 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -196,6 +196,12 @@ void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache);
 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
+int btrfs_update_block_group(struct btrfs_trans_handle *trans,
+			     u64 bytenr, u64 num_bytes, int alloc);
+int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
+			     u64 ram_bytes, u64 num_bytes, int delalloc);
+void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
+			       u64 num_bytes, int delalloc);
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b895380e60b2..e44a6c3d7a9a 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2895,8 +2895,8 @@ int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 	return ret;
 }
 
-static int update_block_group(struct btrfs_trans_handle *trans,
-			      u64 bytenr, u64 num_bytes, int alloc)
+int btrfs_update_block_group(struct btrfs_trans_handle *trans,
+			     u64 bytenr, u64 num_bytes, int alloc)
 {
 	struct btrfs_fs_info *info = trans->fs_info;
 	struct btrfs_block_group_cache *cache = NULL;
@@ -3197,8 +3197,8 @@ btrfs_inc_block_group_reservations(struct btrfs_block_group_cache *bg)
  * reservation and the block group has become read only we cannot make the
  * reservation and return -EAGAIN, otherwise this function always succeeds.
  */
-static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
-				    u64 ram_bytes, u64 num_bytes, int delalloc)
+int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
+			     u64 ram_bytes, u64 num_bytes, int delalloc)
 {
 	struct btrfs_space_info *space_info = cache->space_info;
 	int ret = 0;
@@ -3231,9 +3231,8 @@ static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
  * A and before transaction A commits you free that leaf, you call this with
  * reserve set to 0 in order to clear the reservation.
  */
-
-static void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
-				      u64 num_bytes, int delalloc)
+void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
+			       u64 num_bytes, int delalloc)
 {
 	struct btrfs_space_info *space_info = cache->space_info;
 
@@ -3706,7 +3705,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 			goto out;
 		}
 
-		ret = update_block_group(trans, bytenr, num_bytes, 0);
+		ret = btrfs_update_block_group(trans, bytenr, num_bytes, 0);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
 			goto out;
@@ -4765,7 +4764,7 @@ static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
 	if (ret)
 		return ret;
 
-	ret = update_block_group(trans, ins->objectid, ins->offset, 1);
+	ret = btrfs_update_block_group(trans, ins->objectid, ins->offset, 1);
 	if (ret) { /* -ENOENT, logic error */
 		btrfs_err(fs_info, "update block group failed for %llu %llu",
 			ins->objectid, ins->offset);
@@ -4855,8 +4854,8 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 	if (ret)
 		return ret;
 
-	ret = update_block_group(trans, extent_key.objectid,
-				 fs_info->nodesize, 1);
+	ret = btrfs_update_block_group(trans, extent_key.objectid,
+				       fs_info->nodesize, 1);
 	if (ret) { /* -ENOENT, logic error */
 		btrfs_err(fs_info, "update block group failed for %llu %llu",
 			extent_key.objectid, extent_key.offset);
-- 
2.14.3

[PATCH 20/25] btrfs: migrate the block group space accounting helpers

[Josef Bacik]

We can now easily migrate this code as well.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 174 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/extent-tree.c | 174 -------------------------------------------------
 2 files changed, 174 insertions(+), 174 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 540dc7219f48..6a189ad3e7e1 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -2505,3 +2505,177 @@ int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans)
 	return ret;
 }
 
+int btrfs_update_block_group(struct btrfs_trans_handle *trans,
+			     u64 bytenr, u64 num_bytes, int alloc)
+{
+	struct btrfs_fs_info *info = trans->fs_info;
+	struct btrfs_block_group_cache *cache = NULL;
+	u64 total = num_bytes;
+	u64 old_val;
+	u64 byte_in_group;
+	int factor;
+	int ret = 0;
+
+	/* block accounting for super block */
+	spin_lock(&info->delalloc_root_lock);
+	old_val = btrfs_super_bytes_used(info->super_copy);
+	if (alloc)
+		old_val += num_bytes;
+	else
+		old_val -= num_bytes;
+	btrfs_set_super_bytes_used(info->super_copy, old_val);
+	spin_unlock(&info->delalloc_root_lock);
+
+	while (total) {
+		cache = btrfs_lookup_block_group(info, bytenr);
+		if (!cache) {
+			ret = -ENOENT;
+			break;
+		}
+		factor = btrfs_bg_type_to_factor(cache->flags);
+
+		/*
+		 * If this block group has free space cache written out, we
+		 * need to make sure to load it if we are removing space.  This
+		 * is because we need the unpinning stage to actually add the
+		 * space back to the block group, otherwise we will leak space.
+		 */
+		if (!alloc && cache->cached == BTRFS_CACHE_NO)
+			btrfs_cache_block_group(cache, 1);
+
+		byte_in_group = bytenr - cache->key.objectid;
+		WARN_ON(byte_in_group > cache->key.offset);
+
+		spin_lock(&cache->space_info->lock);
+		spin_lock(&cache->lock);
+
+		if (btrfs_test_opt(info, SPACE_CACHE) &&
+		    cache->disk_cache_state < BTRFS_DC_CLEAR)
+			cache->disk_cache_state = BTRFS_DC_CLEAR;
+
+		old_val = btrfs_block_group_used(&cache->item);
+		num_bytes = min(total, cache->key.offset - byte_in_group);
+		if (alloc) {
+			old_val += num_bytes;
+			btrfs_set_block_group_used(&cache->item, old_val);
+			cache->reserved -= num_bytes;
+			cache->space_info->bytes_reserved -= num_bytes;
+			cache->space_info->bytes_used += num_bytes;
+			cache->space_info->disk_used += num_bytes * factor;
+			spin_unlock(&cache->lock);
+			spin_unlock(&cache->space_info->lock);
+		} else {
+			old_val -= num_bytes;
+			btrfs_set_block_group_used(&cache->item, old_val);
+			cache->pinned += num_bytes;
+			btrfs_space_info_update_bytes_pinned(info,
+							     cache->space_info,
+							     num_bytes);
+			cache->space_info->bytes_used -= num_bytes;
+			cache->space_info->disk_used -= num_bytes * factor;
+			spin_unlock(&cache->lock);
+			spin_unlock(&cache->space_info->lock);
+
+			trace_btrfs_space_reservation(info, "pinned",
+						      cache->space_info->flags,
+						      num_bytes, 1);
+			percpu_counter_add_batch(&cache->space_info->total_bytes_pinned,
+					   num_bytes,
+					   BTRFS_TOTAL_BYTES_PINNED_BATCH);
+			set_extent_dirty(info->pinned_extents,
+					 bytenr, bytenr + num_bytes - 1,
+					 GFP_NOFS | __GFP_NOFAIL);
+		}
+
+		spin_lock(&trans->transaction->dirty_bgs_lock);
+		if (list_empty(&cache->dirty_list)) {
+			list_add_tail(&cache->dirty_list,
+				      &trans->transaction->dirty_bgs);
+			trans->delayed_ref_updates++;
+			btrfs_get_block_group(cache);
+		}
+		spin_unlock(&trans->transaction->dirty_bgs_lock);
+
+		/*
+		 * No longer have used bytes in this block group, queue it for
+		 * deletion. We do this after adding the block group to the
+		 * dirty list to avoid races between cleaner kthread and space
+		 * cache writeout.
+		 */
+		if (!alloc && old_val == 0)
+			btrfs_mark_bg_unused(cache);
+
+		btrfs_put_block_group(cache);
+		total -= num_bytes;
+		bytenr += num_bytes;
+	}
+
+	/* Modified block groups are accounted for in the delayed_refs_rsv. */
+	btrfs_update_delayed_refs_rsv(trans);
+	return ret;
+}
+
+/**
+ * btrfs_add_reserved_bytes - update the block_group and space info counters
+ * @cache:	The cache we are manipulating
+ * @ram_bytes:  The number of bytes of file content, and will be same to
+ *              @num_bytes except for the compress path.
+ * @num_bytes:	The number of bytes in question
+ * @delalloc:   The blocks are allocated for the delalloc write
+ *
+ * This is called by the allocator when it reserves space. If this is a
+ * reservation and the block group has become read only we cannot make the
+ * reservation and return -EAGAIN, otherwise this function always succeeds.
+ */
+int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
+			     u64 ram_bytes, u64 num_bytes, int delalloc)
+{
+	struct btrfs_space_info *space_info = cache->space_info;
+	int ret = 0;
+
+	spin_lock(&space_info->lock);
+	spin_lock(&cache->lock);
+	if (cache->ro) {
+		ret = -EAGAIN;
+	} else {
+		cache->reserved += num_bytes;
+		space_info->bytes_reserved += num_bytes;
+		btrfs_space_info_update_bytes_may_use(cache->fs_info,
+						      space_info, -ram_bytes);
+		if (delalloc)
+			cache->delalloc_bytes += num_bytes;
+	}
+	spin_unlock(&cache->lock);
+	spin_unlock(&space_info->lock);
+	return ret;
+}
+
+/**
+ * btrfs_free_reserved_bytes - update the block_group and space info counters
+ * @cache:      The cache we are manipulating
+ * @num_bytes:  The number of bytes in question
+ * @delalloc:   The blocks are allocated for the delalloc write
+ *
+ * This is called by somebody who is freeing space that was never actually used
+ * on disk.  For example if you reserve some space for a new leaf in transaction
+ * A and before transaction A commits you free that leaf, you call this with
+ * reserve set to 0 in order to clear the reservation.
+ */
+void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
+			       u64 num_bytes, int delalloc)
+{
+	struct btrfs_space_info *space_info = cache->space_info;
+
+	spin_lock(&space_info->lock);
+	spin_lock(&cache->lock);
+	if (cache->ro)
+		space_info->bytes_readonly += num_bytes;
+	cache->reserved -= num_bytes;
+	space_info->bytes_reserved -= num_bytes;
+	space_info->max_extent_size = 0;
+
+	if (delalloc)
+		cache->delalloc_bytes -= num_bytes;
+	spin_unlock(&cache->lock);
+	spin_unlock(&space_info->lock);
+}
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index e44a6c3d7a9a..971d0e336fc2 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2895,116 +2895,6 @@ int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 	return ret;
 }
 
-int btrfs_update_block_group(struct btrfs_trans_handle *trans,
-			     u64 bytenr, u64 num_bytes, int alloc)
-{
-	struct btrfs_fs_info *info = trans->fs_info;
-	struct btrfs_block_group_cache *cache = NULL;
-	u64 total = num_bytes;
-	u64 old_val;
-	u64 byte_in_group;
-	int factor;
-	int ret = 0;
-
-	/* block accounting for super block */
-	spin_lock(&info->delalloc_root_lock);
-	old_val = btrfs_super_bytes_used(info->super_copy);
-	if (alloc)
-		old_val += num_bytes;
-	else
-		old_val -= num_bytes;
-	btrfs_set_super_bytes_used(info->super_copy, old_val);
-	spin_unlock(&info->delalloc_root_lock);
-
-	while (total) {
-		cache = btrfs_lookup_block_group(info, bytenr);
-		if (!cache) {
-			ret = -ENOENT;
-			break;
-		}
-		factor = btrfs_bg_type_to_factor(cache->flags);
-
-		/*
-		 * If this block group has free space cache written out, we
-		 * need to make sure to load it if we are removing space.  This
-		 * is because we need the unpinning stage to actually add the
-		 * space back to the block group, otherwise we will leak space.
-		 */
-		if (!alloc && cache->cached == BTRFS_CACHE_NO)
-			btrfs_cache_block_group(cache, 1);
-
-		byte_in_group = bytenr - cache->key.objectid;
-		WARN_ON(byte_in_group > cache->key.offset);
-
-		spin_lock(&cache->space_info->lock);
-		spin_lock(&cache->lock);
-
-		if (btrfs_test_opt(info, SPACE_CACHE) &&
-		    cache->disk_cache_state < BTRFS_DC_CLEAR)
-			cache->disk_cache_state = BTRFS_DC_CLEAR;
-
-		old_val = btrfs_block_group_used(&cache->item);
-		num_bytes = min(total, cache->key.offset - byte_in_group);
-		if (alloc) {
-			old_val += num_bytes;
-			btrfs_set_block_group_used(&cache->item, old_val);
-			cache->reserved -= num_bytes;
-			cache->space_info->bytes_reserved -= num_bytes;
-			cache->space_info->bytes_used += num_bytes;
-			cache->space_info->disk_used += num_bytes * factor;
-			spin_unlock(&cache->lock);
-			spin_unlock(&cache->space_info->lock);
-		} else {
-			old_val -= num_bytes;
-			btrfs_set_block_group_used(&cache->item, old_val);
-			cache->pinned += num_bytes;
-			btrfs_space_info_update_bytes_pinned(info,
-							     cache->space_info,
-							     num_bytes);
-			cache->space_info->bytes_used -= num_bytes;
-			cache->space_info->disk_used -= num_bytes * factor;
-			spin_unlock(&cache->lock);
-			spin_unlock(&cache->space_info->lock);
-
-			trace_btrfs_space_reservation(info, "pinned",
-						      cache->space_info->flags,
-						      num_bytes, 1);
-			percpu_counter_add_batch(&cache->space_info->total_bytes_pinned,
-					   num_bytes,
-					   BTRFS_TOTAL_BYTES_PINNED_BATCH);
-			set_extent_dirty(info->pinned_extents,
-					 bytenr, bytenr + num_bytes - 1,
-					 GFP_NOFS | __GFP_NOFAIL);
-		}
-
-		spin_lock(&trans->transaction->dirty_bgs_lock);
-		if (list_empty(&cache->dirty_list)) {
-			list_add_tail(&cache->dirty_list,
-				      &trans->transaction->dirty_bgs);
-			trans->delayed_ref_updates++;
-			btrfs_get_block_group(cache);
-		}
-		spin_unlock(&trans->transaction->dirty_bgs_lock);
-
-		/*
-		 * No longer have used bytes in this block group, queue it for
-		 * deletion. We do this after adding the block group to the
-		 * dirty list to avoid races between cleaner kthread and space
-		 * cache writeout.
-		 */
-		if (!alloc && old_val == 0)
-			btrfs_mark_bg_unused(cache);
-
-		btrfs_put_block_group(cache);
-		total -= num_bytes;
-		bytenr += num_bytes;
-	}
-
-	/* Modified block groups are accounted for in the delayed_refs_rsv. */
-	btrfs_update_delayed_refs_rsv(trans);
-	return ret;
-}
-
 static u64 first_logical_byte(struct btrfs_fs_info *fs_info, u64 search_start)
 {
 	struct btrfs_block_group_cache *cache;
@@ -3185,70 +3075,6 @@ btrfs_inc_block_group_reservations(struct btrfs_block_group_cache *bg)
 	atomic_inc(&bg->reservations);
 }
 
-/**
- * btrfs_add_reserved_bytes - update the block_group and space info counters
- * @cache:	The cache we are manipulating
- * @ram_bytes:  The number of bytes of file content, and will be same to
- *              @num_bytes except for the compress path.
- * @num_bytes:	The number of bytes in question
- * @delalloc:   The blocks are allocated for the delalloc write
- *
- * This is called by the allocator when it reserves space. If this is a
- * reservation and the block group has become read only we cannot make the
- * reservation and return -EAGAIN, otherwise this function always succeeds.
- */
-int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
-			     u64 ram_bytes, u64 num_bytes, int delalloc)
-{
-	struct btrfs_space_info *space_info = cache->space_info;
-	int ret = 0;
-
-	spin_lock(&space_info->lock);
-	spin_lock(&cache->lock);
-	if (cache->ro) {
-		ret = -EAGAIN;
-	} else {
-		cache->reserved += num_bytes;
-		space_info->bytes_reserved += num_bytes;
-		btrfs_space_info_update_bytes_may_use(cache->fs_info,
-						      space_info, -ram_bytes);
-		if (delalloc)
-			cache->delalloc_bytes += num_bytes;
-	}
-	spin_unlock(&cache->lock);
-	spin_unlock(&space_info->lock);
-	return ret;
-}
-
-/**
- * btrfs_free_reserved_bytes - update the block_group and space info counters
- * @cache:      The cache we are manipulating
- * @num_bytes:  The number of bytes in question
- * @delalloc:   The blocks are allocated for the delalloc write
- *
- * This is called by somebody who is freeing space that was never actually used
- * on disk.  For example if you reserve some space for a new leaf in transaction
- * A and before transaction A commits you free that leaf, you call this with
- * reserve set to 0 in order to clear the reservation.
- */
-void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
-			       u64 num_bytes, int delalloc)
-{
-	struct btrfs_space_info *space_info = cache->space_info;
-
-	spin_lock(&space_info->lock);
-	spin_lock(&cache->lock);
-	if (cache->ro)
-		space_info->bytes_readonly += num_bytes;
-	cache->reserved -= num_bytes;
-	space_info->bytes_reserved -= num_bytes;
-	space_info->max_extent_size = 0;
-
-	if (delalloc)
-		cache->delalloc_bytes -= num_bytes;
-	spin_unlock(&cache->lock);
-	spin_unlock(&space_info->lock);
-}
 void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_caching_control *next;
-- 
2.14.3

[PATCH 21/25] btrfs: migrate btrfs_can_relocate

[Josef Bacik]

This belongs to block-group.c, move it over.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |   1 +
 fs/btrfs/ctree.h       |   1 -
 fs/btrfs/extent-tree.c | 141 -------------------------------------------------
 4 files changed, 142 insertions(+), 142 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 6a189ad3e7e1..4d029089ec32 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -2679,3 +2679,144 @@ void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
 	spin_unlock(&cache->lock);
 	spin_unlock(&space_info->lock);
 }
+
+/*
+ * Checks to see if it's even possible to relocate this block group.
+ *
+ * @return - -1 if it's not a good idea to relocate this block group, 0 if its
+ * ok to go ahead and try.
+ */
+int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr)
+{
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_space_info *space_info;
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+	struct btrfs_device *device;
+	u64 min_free;
+	u64 dev_min = 1;
+	u64 dev_nr = 0;
+	u64 target;
+	int debug;
+	int index;
+	int full = 0;
+	int ret = 0;
+
+	debug = btrfs_test_opt(fs_info, ENOSPC_DEBUG);
+
+	block_group = btrfs_lookup_block_group(fs_info, bytenr);
+
+	/* odd, couldn't find the block group, leave it alone */
+	if (!block_group) {
+		if (debug)
+			btrfs_warn(fs_info,
+				   "can't find block group for bytenr %llu",
+				   bytenr);
+		return -1;
+	}
+
+	min_free = btrfs_block_group_used(&block_group->item);
+
+	/* no bytes used, we're good */
+	if (!min_free)
+		goto out;
+
+	space_info = block_group->space_info;
+	spin_lock(&space_info->lock);
+
+	full = space_info->full;
+
+	/*
+	 * if this is the last block group we have in this space, we can't
+	 * relocate it unless we're able to allocate a new chunk below.
+	 *
+	 * Otherwise, we need to make sure we have room in the space to handle
+	 * all of the extents from this block group.  If we can, we're good
+	 */
+	if ((space_info->total_bytes != block_group->key.offset) &&
+	    (btrfs_space_info_used(space_info, false) + min_free <
+	     space_info->total_bytes)) {
+		spin_unlock(&space_info->lock);
+		goto out;
+	}
+	spin_unlock(&space_info->lock);
+
+	/*
+	 * ok we don't have enough space, but maybe we have free space on our
+	 * devices to allocate new chunks for relocation, so loop through our
+	 * alloc devices and guess if we have enough space.  if this block
+	 * group is going to be restriped, run checks against the target
+	 * profile instead of the current one.
+	 */
+	ret = -1;
+
+	/*
+	 * index:
+	 *      0: raid10
+	 *      1: raid1
+	 *      2: dup
+	 *      3: raid0
+	 *      4: single
+	 */
+	target = btrfs_get_restripe_target(fs_info, block_group->flags);
+	if (target) {
+		index = btrfs_bg_flags_to_raid_index(extended_to_chunk(target));
+	} else {
+		/*
+		 * this is just a balance, so if we were marked as full
+		 * we know there is no space for a new chunk
+		 */
+		if (full) {
+			if (debug)
+				btrfs_warn(fs_info,
+					   "no space to alloc new chunk for block group %llu",
+					   block_group->key.objectid);
+			goto out;
+		}
+
+		index = btrfs_bg_flags_to_raid_index(block_group->flags);
+	}
+
+	if (index == BTRFS_RAID_RAID10) {
+		dev_min = 4;
+		/* Divide by 2 */
+		min_free >>= 1;
+	} else if (index == BTRFS_RAID_RAID1) {
+		dev_min = 2;
+	} else if (index == BTRFS_RAID_DUP) {
+		/* Multiply by 2 */
+		min_free <<= 1;
+	} else if (index == BTRFS_RAID_RAID0) {
+		dev_min = fs_devices->rw_devices;
+		min_free = div64_u64(min_free, dev_min);
+	}
+
+	mutex_lock(&fs_info->chunk_mutex);
+	list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
+		u64 dev_offset;
+
+		/*
+		 * check to make sure we can actually find a chunk with enough
+		 * space to fit our block group in.
+		 */
+		if (device->total_bytes > device->bytes_used + min_free &&
+		    !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
+			ret = find_free_dev_extent(device, min_free,
+						   &dev_offset, NULL);
+			if (!ret)
+				dev_nr++;
+
+			if (dev_nr >= dev_min)
+				break;
+
+			ret = -1;
+		}
+	}
+	if (debug && ret == -1)
+		btrfs_warn(fs_info,
+			   "no space to allocate a new chunk for block group %llu",
+			   block_group->key.objectid);
+	mutex_unlock(&fs_info->chunk_mutex);
+out:
+	btrfs_put_block_group(block_group);
+	return ret;
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 3b7516836849..328cbffc5ce8 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -202,6 +202,7 @@ int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
 			     u64 ram_bytes, u64 num_bytes, int delalloc);
 void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
 			       u64 num_bytes, int delalloc);
+int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr);
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 15ab2d5f7cd7..e6b32c0fcbb4 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2520,7 +2520,6 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 
 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr);
 int btrfs_free_block_groups(struct btrfs_fs_info *info);
-int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr);
 void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info);
 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *cache);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 971d0e336fc2..b72bc622cb9a 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5873,147 +5873,6 @@ u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
 	return free_bytes;
 }
 
-/*
- * Checks to see if it's even possible to relocate this block group.
- *
- * @return - -1 if it's not a good idea to relocate this block group, 0 if its
- * ok to go ahead and try.
- */
-int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_space_info *space_info;
-	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
-	struct btrfs_device *device;
-	u64 min_free;
-	u64 dev_min = 1;
-	u64 dev_nr = 0;
-	u64 target;
-	int debug;
-	int index;
-	int full = 0;
-	int ret = 0;
-
-	debug = btrfs_test_opt(fs_info, ENOSPC_DEBUG);
-
-	block_group = btrfs_lookup_block_group(fs_info, bytenr);
-
-	/* odd, couldn't find the block group, leave it alone */
-	if (!block_group) {
-		if (debug)
-			btrfs_warn(fs_info,
-				   "can't find block group for bytenr %llu",
-				   bytenr);
-		return -1;
-	}
-
-	min_free = btrfs_block_group_used(&block_group->item);
-
-	/* no bytes used, we're good */
-	if (!min_free)
-		goto out;
-
-	space_info = block_group->space_info;
-	spin_lock(&space_info->lock);
-
-	full = space_info->full;
-
-	/*
-	 * if this is the last block group we have in this space, we can't
-	 * relocate it unless we're able to allocate a new chunk below.
-	 *
-	 * Otherwise, we need to make sure we have room in the space to handle
-	 * all of the extents from this block group.  If we can, we're good
-	 */
-	if ((space_info->total_bytes != block_group->key.offset) &&
-	    (btrfs_space_info_used(space_info, false) + min_free <
-	     space_info->total_bytes)) {
-		spin_unlock(&space_info->lock);
-		goto out;
-	}
-	spin_unlock(&space_info->lock);
-
-	/*
-	 * ok we don't have enough space, but maybe we have free space on our
-	 * devices to allocate new chunks for relocation, so loop through our
-	 * alloc devices and guess if we have enough space.  if this block
-	 * group is going to be restriped, run checks against the target
-	 * profile instead of the current one.
-	 */
-	ret = -1;
-
-	/*
-	 * index:
-	 *      0: raid10
-	 *      1: raid1
-	 *      2: dup
-	 *      3: raid0
-	 *      4: single
-	 */
-	target = btrfs_get_restripe_target(fs_info, block_group->flags);
-	if (target) {
-		index = btrfs_bg_flags_to_raid_index(extended_to_chunk(target));
-	} else {
-		/*
-		 * this is just a balance, so if we were marked as full
-		 * we know there is no space for a new chunk
-		 */
-		if (full) {
-			if (debug)
-				btrfs_warn(fs_info,
-					   "no space to alloc new chunk for block group %llu",
-					   block_group->key.objectid);
-			goto out;
-		}
-
-		index = btrfs_bg_flags_to_raid_index(block_group->flags);
-	}
-
-	if (index == BTRFS_RAID_RAID10) {
-		dev_min = 4;
-		/* Divide by 2 */
-		min_free >>= 1;
-	} else if (index == BTRFS_RAID_RAID1) {
-		dev_min = 2;
-	} else if (index == BTRFS_RAID_DUP) {
-		/* Multiply by 2 */
-		min_free <<= 1;
-	} else if (index == BTRFS_RAID_RAID0) {
-		dev_min = fs_devices->rw_devices;
-		min_free = div64_u64(min_free, dev_min);
-	}
-
-	mutex_lock(&fs_info->chunk_mutex);
-	list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
-		u64 dev_offset;
-
-		/*
-		 * check to make sure we can actually find a chunk with enough
-		 * space to fit our block group in.
-		 */
-		if (device->total_bytes > device->bytes_used + min_free &&
-		    !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
-			ret = find_free_dev_extent(device, min_free,
-						   &dev_offset, NULL);
-			if (!ret)
-				dev_nr++;
-
-			if (dev_nr >= dev_min)
-				break;
-
-			ret = -1;
-		}
-	}
-	if (debug && ret == -1)
-		btrfs_warn(fs_info,
-			   "no space to allocate a new chunk for block group %llu",
-			   block_group->key.objectid);
-	mutex_unlock(&fs_info->chunk_mutex);
-out:
-	btrfs_put_block_group(block_group);
-	return ret;
-}
-
 void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
 {
 	struct btrfs_block_group_cache *block_group;
-- 
2.14.3

[PATCH 22/25] btrfs: migrate the chunk allocation code

[Josef Bacik]

This feels more at home in block-group.c than in extent-tree.c.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c    | 247 ++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h    |  24 +++++
 fs/btrfs/ctree.h          |  24 -----
 fs/btrfs/delalloc-space.c |   1 +
 fs/btrfs/extent-tree.c    | 246 ---------------------------------------------
 5 files changed, 272 insertions(+), 270 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 4d029089ec32..942763738457 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -15,6 +15,7 @@
 #include "sysfs.h"
 #include "tree-log.h"
 #include "delalloc-space.h"
+#include "math.h"
 
 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
 {
@@ -2820,3 +2821,249 @@ int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr)
 	btrfs_put_block_group(block_group);
 	return ret;
 }
+
+static void force_metadata_allocation(struct btrfs_fs_info *info)
+{
+	struct list_head *head = &info->space_info;
+	struct btrfs_space_info *found;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(found, head, list) {
+		if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
+			found->force_alloc = CHUNK_ALLOC_FORCE;
+	}
+	rcu_read_unlock();
+}
+
+static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
+			      struct btrfs_space_info *sinfo, int force)
+{
+	u64 bytes_used = btrfs_space_info_used(sinfo, false);
+	u64 thresh;
+
+	if (force == CHUNK_ALLOC_FORCE)
+		return 1;
+
+	/*
+	 * in limited mode, we want to have some free space up to
+	 * about 1% of the FS size.
+	 */
+	if (force == CHUNK_ALLOC_LIMITED) {
+		thresh = btrfs_super_total_bytes(fs_info->super_copy);
+		thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1));
+
+		if (sinfo->total_bytes - bytes_used < thresh)
+			return 1;
+	}
+
+	if (bytes_used + SZ_2M < div_factor(sinfo->total_bytes, 8))
+		return 0;
+	return 1;
+}
+
+int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type)
+{
+	u64 alloc_flags = btrfs_get_alloc_profile(trans->fs_info, type);
+
+	return btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
+}
+
+/*
+ * If force is CHUNK_ALLOC_FORCE:
+ *    - return 1 if it successfully allocates a chunk,
+ *    - return errors including -ENOSPC otherwise.
+ * If force is NOT CHUNK_ALLOC_FORCE:
+ *    - return 0 if it doesn't need to allocate a new chunk,
+ *    - return 1 if it successfully allocates a chunk,
+ *    - return errors including -ENOSPC otherwise.
+ */
+int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
+		      enum btrfs_chunk_alloc_enum force)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_space_info *space_info;
+	bool wait_for_alloc = false;
+	bool should_alloc = false;
+	int ret = 0;
+	int orig_force = force;
+
+	/* Don't re-enter if we're already allocating a chunk */
+	if (trans->allocating_chunk)
+		return -ENOSPC;
+
+	space_info = btrfs_find_space_info(fs_info, flags);
+	ASSERT(space_info);
+
+	do {
+		spin_lock(&space_info->lock);
+		if (force < space_info->force_alloc)
+			force = space_info->force_alloc;
+		should_alloc = should_alloc_chunk(fs_info, space_info, force);
+		if (space_info->full) {
+			/* No more free physical space */
+			if (should_alloc)
+				ret = -ENOSPC;
+			else
+				ret = 0;
+			spin_unlock(&space_info->lock);
+			return ret;
+		} else if (!should_alloc) {
+			spin_unlock(&space_info->lock);
+			return 0;
+		} else if (space_info->chunk_alloc) {
+			/*
+			 * Someone is already allocating, so we need to block
+			 * until this someone is finished and then loop to
+			 * recheck if we should continue with our allocation
+			 * attempt.
+			 */
+			wait_for_alloc = true;
+			spin_unlock(&space_info->lock);
+			force = orig_force;
+			mutex_lock(&fs_info->chunk_mutex);
+			mutex_unlock(&fs_info->chunk_mutex);
+		} else {
+			/* Proceed with allocation */
+			space_info->chunk_alloc = 1;
+			wait_for_alloc = false;
+			spin_unlock(&space_info->lock);
+		}
+
+		cond_resched();
+	} while (wait_for_alloc);
+
+	mutex_lock(&fs_info->chunk_mutex);
+	trans->allocating_chunk = true;
+
+	/*
+	 * If we have mixed data/metadata chunks we want to make sure we keep
+	 * allocating mixed chunks instead of individual chunks.
+	 */
+	if (btrfs_mixed_space_info(space_info))
+		flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
+
+	/*
+	 * if we're doing a data chunk, go ahead and make sure that
+	 * we keep a reasonable number of metadata chunks allocated in the
+	 * FS as well.
+	 */
+	if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
+		fs_info->data_chunk_allocations++;
+		if (!(fs_info->data_chunk_allocations %
+		      fs_info->metadata_ratio))
+			force_metadata_allocation(fs_info);
+	}
+
+	/*
+	 * Check if we have enough space in SYSTEM chunk because we may need
+	 * to update devices.
+	 */
+	check_system_chunk(trans, flags);
+
+	ret = btrfs_alloc_chunk(trans, flags);
+	trans->allocating_chunk = false;
+
+	spin_lock(&space_info->lock);
+	if (ret < 0) {
+		if (ret == -ENOSPC)
+			space_info->full = 1;
+		else
+			goto out;
+	} else {
+		ret = 1;
+		space_info->max_extent_size = 0;
+	}
+
+	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
+out:
+	space_info->chunk_alloc = 0;
+	spin_unlock(&space_info->lock);
+	mutex_unlock(&fs_info->chunk_mutex);
+	/*
+	 * When we allocate a new chunk we reserve space in the chunk block
+	 * reserve to make sure we can COW nodes/leafs in the chunk tree or
+	 * add new nodes/leafs to it if we end up needing to do it when
+	 * inserting the chunk item and updating device items as part of the
+	 * second phase of chunk allocation, performed by
+	 * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
+	 * large number of new block groups to create in our transaction
+	 * handle's new_bgs list to avoid exhausting the chunk block reserve
+	 * in extreme cases - like having a single transaction create many new
+	 * block groups when starting to write out the free space caches of all
+	 * the block groups that were made dirty during the lifetime of the
+	 * transaction.
+	 */
+	if (trans->chunk_bytes_reserved >= (u64)SZ_2M)
+		btrfs_create_pending_block_groups(trans);
+
+	return ret;
+}
+
+static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type)
+{
+	u64 num_dev;
+
+	num_dev = btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)].devs_max;
+	if (!num_dev)
+		num_dev = fs_info->fs_devices->rw_devices;
+
+	return num_dev;
+}
+
+/*
+ * If @is_allocation is true, reserve space in the system space info necessary
+ * for allocating a chunk, otherwise if it's false, reserve space necessary for
+ * removing a chunk.
+ */
+void check_system_chunk(struct btrfs_trans_handle *trans, u64 type)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_space_info *info;
+	u64 left;
+	u64 thresh;
+	int ret = 0;
+	u64 num_devs;
+
+	/*
+	 * Needed because we can end up allocating a system chunk and for an
+	 * atomic and race free space reservation in the chunk block reserve.
+	 */
+	lockdep_assert_held(&fs_info->chunk_mutex);
+
+	info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
+	spin_lock(&info->lock);
+	left = info->total_bytes - btrfs_space_info_used(info, true);
+	spin_unlock(&info->lock);
+
+	num_devs = get_profile_num_devs(fs_info, type);
+
+	/* num_devs device items to update and 1 chunk item to add or remove */
+	thresh = btrfs_calc_trunc_metadata_size(fs_info, num_devs) +
+		btrfs_calc_trans_metadata_size(fs_info, 1);
+
+	if (left < thresh && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
+		btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu",
+			   left, thresh, type);
+		btrfs_dump_space_info(fs_info, info, 0, 0);
+	}
+
+	if (left < thresh) {
+		u64 flags = btrfs_system_alloc_profile(fs_info);
+
+		/*
+		 * Ignore failure to create system chunk. We might end up not
+		 * needing it, as we might not need to COW all nodes/leafs from
+		 * the paths we visit in the chunk tree (they were already COWed
+		 * or created in the current transaction for example).
+		 */
+		ret = btrfs_alloc_chunk(trans, flags);
+	}
+
+	if (!ret) {
+		ret = btrfs_block_rsv_add(fs_info->chunk_root,
+					  &fs_info->chunk_block_rsv,
+					  thresh, BTRFS_RESERVE_NO_FLUSH);
+		if (!ret)
+			trans->chunk_bytes_reserved += thresh;
+	}
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 328cbffc5ce8..ee34d4e9d0b7 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -13,6 +13,26 @@ enum btrfs_disk_cache_state {
 	BTRFS_DC_SETUP,
 };
 
+/*
+ * control flags for do_chunk_alloc's force field
+ * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
+ * if we really need one.
+ *
+ * CHUNK_ALLOC_LIMITED means to only try and allocate one
+ * if we have very few chunks already allocated.  This is
+ * used as part of the clustering code to help make sure
+ * we have a good pool of storage to cluster in, without
+ * filling the FS with empty chunks
+ *
+ * CHUNK_ALLOC_FORCE means it must try to allocate one
+ *
+ */
+enum btrfs_chunk_alloc_enum {
+	CHUNK_ALLOC_NO_FORCE = 0,
+	CHUNK_ALLOC_LIMITED = 1,
+	CHUNK_ALLOC_FORCE = 2,
+};
+
 struct btrfs_caching_control {
 	struct list_head list;
 	struct mutex mutex;
@@ -203,6 +223,10 @@ int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
 void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
 			       u64 num_bytes, int delalloc);
 int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr);
+int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
+		      enum btrfs_chunk_alloc_enum force);
+int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
+void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e6b32c0fcbb4..1cf7f47484b6 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2551,28 +2551,6 @@ enum btrfs_flush_state {
 	COMMIT_TRANS		=	9,
 };
 
-/*
- * control flags for do_chunk_alloc's force field
- * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
- * if we really need one.
- *
- * CHUNK_ALLOC_LIMITED means to only try and allocate one
- * if we have very few chunks already allocated.  This is
- * used as part of the clustering code to help make sure
- * we have a good pool of storage to cluster in, without
- * filling the FS with empty chunks
- *
- * CHUNK_ALLOC_FORCE means it must try to allocate one
- *
- */
-enum btrfs_chunk_alloc_enum {
-	CHUNK_ALLOC_NO_FORCE = 0,
-	CHUNK_ALLOC_LIMITED = 1,
-	CHUNK_ALLOC_FORCE = 2,
-};
-
-int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
-		      enum btrfs_chunk_alloc_enum force);
 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
 				     struct btrfs_block_rsv *rsv,
 				     int nitems, bool use_global_rsv);
@@ -2588,7 +2566,6 @@ int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
 				   u64 start, u64 end);
 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
 			 u64 num_bytes, u64 *actual_bytes);
-int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range);
 
 int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
@@ -2597,7 +2574,6 @@ int btrfs_delayed_refs_qgroup_accounting(struct btrfs_trans_handle *trans,
 int btrfs_start_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_end_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_wait_for_snapshot_creation(struct btrfs_root *root);
-void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
 
 /* ctree.c */
 int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
diff --git a/fs/btrfs/delalloc-space.c b/fs/btrfs/delalloc-space.c
index 260c152d0d84..764ef6b6e58a 100644
--- a/fs/btrfs/delalloc-space.c
+++ b/fs/btrfs/delalloc-space.c
@@ -10,6 +10,7 @@
 #include "space-info.h"
 #include "transaction.h"
 #include "qgroup.h"
+#include "block-group.h"
 
 int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes)
 {
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b72bc622cb9a..70f6d5fce42e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2656,245 +2656,6 @@ u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
 	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 }
 
-static void force_metadata_allocation(struct btrfs_fs_info *info)
-{
-	struct list_head *head = &info->space_info;
-	struct btrfs_space_info *found;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(found, head, list) {
-		if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
-			found->force_alloc = CHUNK_ALLOC_FORCE;
-	}
-	rcu_read_unlock();
-}
-
-static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
-			      struct btrfs_space_info *sinfo, int force)
-{
-	u64 bytes_used = btrfs_space_info_used(sinfo, false);
-	u64 thresh;
-
-	if (force == CHUNK_ALLOC_FORCE)
-		return 1;
-
-	/*
-	 * in limited mode, we want to have some free space up to
-	 * about 1% of the FS size.
-	 */
-	if (force == CHUNK_ALLOC_LIMITED) {
-		thresh = btrfs_super_total_bytes(fs_info->super_copy);
-		thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1));
-
-		if (sinfo->total_bytes - bytes_used < thresh)
-			return 1;
-	}
-
-	if (bytes_used + SZ_2M < div_factor(sinfo->total_bytes, 8))
-		return 0;
-	return 1;
-}
-
-static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type)
-{
-	u64 num_dev;
-
-	num_dev = btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)].devs_max;
-	if (!num_dev)
-		num_dev = fs_info->fs_devices->rw_devices;
-
-	return num_dev;
-}
-
-/*
- * If @is_allocation is true, reserve space in the system space info necessary
- * for allocating a chunk, otherwise if it's false, reserve space necessary for
- * removing a chunk.
- */
-void check_system_chunk(struct btrfs_trans_handle *trans, u64 type)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_space_info *info;
-	u64 left;
-	u64 thresh;
-	int ret = 0;
-	u64 num_devs;
-
-	/*
-	 * Needed because we can end up allocating a system chunk and for an
-	 * atomic and race free space reservation in the chunk block reserve.
-	 */
-	lockdep_assert_held(&fs_info->chunk_mutex);
-
-	info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
-	spin_lock(&info->lock);
-	left = info->total_bytes - btrfs_space_info_used(info, true);
-	spin_unlock(&info->lock);
-
-	num_devs = get_profile_num_devs(fs_info, type);
-
-	/* num_devs device items to update and 1 chunk item to add or remove */
-	thresh = btrfs_calc_trunc_metadata_size(fs_info, num_devs) +
-		btrfs_calc_trans_metadata_size(fs_info, 1);
-
-	if (left < thresh && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
-		btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu",
-			   left, thresh, type);
-		btrfs_dump_space_info(fs_info, info, 0, 0);
-	}
-
-	if (left < thresh) {
-		u64 flags = btrfs_system_alloc_profile(fs_info);
-
-		/*
-		 * Ignore failure to create system chunk. We might end up not
-		 * needing it, as we might not need to COW all nodes/leafs from
-		 * the paths we visit in the chunk tree (they were already COWed
-		 * or created in the current transaction for example).
-		 */
-		ret = btrfs_alloc_chunk(trans, flags);
-	}
-
-	if (!ret) {
-		ret = btrfs_block_rsv_add(fs_info->chunk_root,
-					  &fs_info->chunk_block_rsv,
-					  thresh, BTRFS_RESERVE_NO_FLUSH);
-		if (!ret)
-			trans->chunk_bytes_reserved += thresh;
-	}
-}
-
-/*
- * If force is CHUNK_ALLOC_FORCE:
- *    - return 1 if it successfully allocates a chunk,
- *    - return errors including -ENOSPC otherwise.
- * If force is NOT CHUNK_ALLOC_FORCE:
- *    - return 0 if it doesn't need to allocate a new chunk,
- *    - return 1 if it successfully allocates a chunk,
- *    - return errors including -ENOSPC otherwise.
- */
-int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
-		      enum btrfs_chunk_alloc_enum force)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_space_info *space_info;
-	bool wait_for_alloc = false;
-	bool should_alloc = false;
-	int ret = 0;
-	int orig_force = force;
-
-	/* Don't re-enter if we're already allocating a chunk */
-	if (trans->allocating_chunk)
-		return -ENOSPC;
-
-	space_info = btrfs_find_space_info(fs_info, flags);
-	ASSERT(space_info);
-
-	do {
-		spin_lock(&space_info->lock);
-		if (force < space_info->force_alloc)
-			force = space_info->force_alloc;
-		should_alloc = should_alloc_chunk(fs_info, space_info, force);
-		if (space_info->full) {
-			/* No more free physical space */
-			if (should_alloc)
-				ret = -ENOSPC;
-			else
-				ret = 0;
-			spin_unlock(&space_info->lock);
-			return ret;
-		} else if (!should_alloc) {
-			spin_unlock(&space_info->lock);
-			return 0;
-		} else if (space_info->chunk_alloc) {
-			/*
-			 * Someone is already allocating, so we need to block
-			 * until this someone is finished and then loop to
-			 * recheck if we should continue with our allocation
-			 * attempt.
-			 */
-			wait_for_alloc = true;
-			spin_unlock(&space_info->lock);
-			force = orig_force;
-			mutex_lock(&fs_info->chunk_mutex);
-			mutex_unlock(&fs_info->chunk_mutex);
-		} else {
-			/* Proceed with allocation */
-			space_info->chunk_alloc = 1;
-			wait_for_alloc = false;
-			spin_unlock(&space_info->lock);
-		}
-
-		cond_resched();
-	} while (wait_for_alloc);
-
-	mutex_lock(&fs_info->chunk_mutex);
-	trans->allocating_chunk = true;
-
-	/*
-	 * If we have mixed data/metadata chunks we want to make sure we keep
-	 * allocating mixed chunks instead of individual chunks.
-	 */
-	if (btrfs_mixed_space_info(space_info))
-		flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
-
-	/*
-	 * if we're doing a data chunk, go ahead and make sure that
-	 * we keep a reasonable number of metadata chunks allocated in the
-	 * FS as well.
-	 */
-	if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
-		fs_info->data_chunk_allocations++;
-		if (!(fs_info->data_chunk_allocations %
-		      fs_info->metadata_ratio))
-			force_metadata_allocation(fs_info);
-	}
-
-	/*
-	 * Check if we have enough space in SYSTEM chunk because we may need
-	 * to update devices.
-	 */
-	check_system_chunk(trans, flags);
-
-	ret = btrfs_alloc_chunk(trans, flags);
-	trans->allocating_chunk = false;
-
-	spin_lock(&space_info->lock);
-	if (ret < 0) {
-		if (ret == -ENOSPC)
-			space_info->full = 1;
-		else
-			goto out;
-	} else {
-		ret = 1;
-		space_info->max_extent_size = 0;
-	}
-
-	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
-out:
-	space_info->chunk_alloc = 0;
-	spin_unlock(&space_info->lock);
-	mutex_unlock(&fs_info->chunk_mutex);
-	/*
-	 * When we allocate a new chunk we reserve space in the chunk block
-	 * reserve to make sure we can COW nodes/leafs in the chunk tree or
-	 * add new nodes/leafs to it if we end up needing to do it when
-	 * inserting the chunk item and updating device items as part of the
-	 * second phase of chunk allocation, performed by
-	 * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
-	 * large number of new block groups to create in our transaction
-	 * handle's new_bgs list to avoid exhausting the chunk block reserve
-	 * in extreme cases - like having a single transaction create many new
-	 * block groups when starting to write out the free space caches of all
-	 * the block groups that were made dirty during the lifetime of the
-	 * transaction.
-	 */
-	if (trans->chunk_bytes_reserved >= (u64)SZ_2M)
-		btrfs_create_pending_block_groups(trans);
-
-	return ret;
-}
-
 static u64 first_logical_byte(struct btrfs_fs_info *fs_info, u64 search_start)
 {
 	struct btrfs_block_group_cache *cache;
@@ -5831,13 +5592,6 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type)
-{
-	u64 alloc_flags = btrfs_get_alloc_profile(trans->fs_info, type);
-
-	return btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
-}
-
 /*
  * helper to account the unused space of all the readonly block group in the
  * space_info. takes mirrors into account.
-- 
2.14.3

[PATCH 23/25] btrfs: migrate the alloc_profile helpers

[Josef Bacik]

These feel more at home in block-group.c.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 100 ++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |  16 +++++++
 fs/btrfs/ctree.h       |   4 --
 fs/btrfs/extent-tree.c | 115 -------------------------------------------------
 4 files changed, 116 insertions(+), 119 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 942763738457..579073ec62c3 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -17,6 +17,106 @@
 #include "delalloc-space.h"
 #include "math.h"
 
+/*
+ * returns target flags in extended format or 0 if restripe for this
+ * chunk_type is not in progress
+ *
+ * should be called with balance_lock held
+ */
+u64 btrfs_get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
+	u64 target = 0;
+
+	if (!bctl)
+		return 0;
+
+	if (flags & BTRFS_BLOCK_GROUP_DATA &&
+	    bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+		target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
+	} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
+		   bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+		target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
+	} else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
+		   bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+		target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
+	}
+
+	return target;
+}
+
+/*
+ * @flags: available profiles in extended format (see ctree.h)
+ *
+ * Returns reduced profile in chunk format.  If profile changing is in
+ * progress (either running or paused) picks the target profile (if it's
+ * already available), otherwise falls back to plain reducing.
+ */
+static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	u64 num_devices = fs_info->fs_devices->rw_devices;
+	u64 target;
+	u64 raid_type;
+	u64 allowed = 0;
+
+	/*
+	 * see if restripe for this chunk_type is in progress, if so
+	 * try to reduce to the target profile
+	 */
+	spin_lock(&fs_info->balance_lock);
+	target = btrfs_get_restripe_target(fs_info, flags);
+	if (target) {
+		/* pick target profile only if it's already available */
+		if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
+			spin_unlock(&fs_info->balance_lock);
+			return extended_to_chunk(target);
+		}
+	}
+	spin_unlock(&fs_info->balance_lock);
+
+	/* First, mask out the RAID levels which aren't possible */
+	for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
+		if (num_devices >= btrfs_raid_array[raid_type].devs_min)
+			allowed |= btrfs_raid_array[raid_type].bg_flag;
+	}
+	allowed &= flags;
+
+	if (allowed & BTRFS_BLOCK_GROUP_RAID6)
+		allowed = BTRFS_BLOCK_GROUP_RAID6;
+	else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
+		allowed = BTRFS_BLOCK_GROUP_RAID5;
+	else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
+		allowed = BTRFS_BLOCK_GROUP_RAID10;
+	else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
+		allowed = BTRFS_BLOCK_GROUP_RAID1;
+	else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
+		allowed = BTRFS_BLOCK_GROUP_RAID0;
+
+	flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
+
+	return extended_to_chunk(flags | allowed);
+}
+
+u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
+{
+	unsigned seq;
+	u64 flags;
+
+	do {
+		flags = orig_flags;
+		seq = read_seqbegin(&fs_info->profiles_lock);
+
+		if (flags & BTRFS_BLOCK_GROUP_DATA)
+			flags |= fs_info->avail_data_alloc_bits;
+		else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+			flags |= fs_info->avail_system_alloc_bits;
+		else if (flags & BTRFS_BLOCK_GROUP_METADATA)
+			flags |= fs_info->avail_metadata_alloc_bits;
+	} while (read_seqretry(&fs_info->profiles_lock, seq));
+
+	return btrfs_reduce_alloc_profile(fs_info, flags);
+}
+
 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
 {
 	atomic_inc(&cache->count);
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index ee34d4e9d0b7..9f6ddb5c9fef 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -227,6 +227,22 @@ int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 		      enum btrfs_chunk_alloc_enum force);
 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
+u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
+
+static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
+{
+	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
+}
+
+static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
+{
+	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+}
+
+static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
+{
+	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
+}
 
 static inline int
 btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1cf7f47484b6..1d1872e93996 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2463,7 +2463,6 @@ static inline u64 btrfs_calc_trunc_metadata_size(struct btrfs_fs_info *fs_info,
 int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
 			      u64 start, u64 num_bytes);
 void btrfs_free_excluded_extents(struct btrfs_block_group_cache *cache);
-u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   unsigned long count);
 void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
@@ -2523,9 +2522,6 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info);
 void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info);
 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *cache);
-u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info);
-u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info);
-u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info);
 void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
 
 enum btrfs_reserve_flush_enum {
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 70f6d5fce42e..53b164964b3b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2524,106 +2524,6 @@ int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
 	return readonly;
 }
 
-/*
- * returns target flags in extended format or 0 if restripe for this
- * chunk_type is not in progress
- *
- * should be called with balance_lock held
- */
-u64 btrfs_get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
-	u64 target = 0;
-
-	if (!bctl)
-		return 0;
-
-	if (flags & BTRFS_BLOCK_GROUP_DATA &&
-	    bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-		target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
-	} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
-		   bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-		target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
-	} else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
-		   bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-		target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
-	}
-
-	return target;
-}
-
-/*
- * @flags: available profiles in extended format (see ctree.h)
- *
- * Returns reduced profile in chunk format.  If profile changing is in
- * progress (either running or paused) picks the target profile (if it's
- * already available), otherwise falls back to plain reducing.
- */
-static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 num_devices = fs_info->fs_devices->rw_devices;
-	u64 target;
-	u64 raid_type;
-	u64 allowed = 0;
-
-	/*
-	 * see if restripe for this chunk_type is in progress, if so
-	 * try to reduce to the target profile
-	 */
-	spin_lock(&fs_info->balance_lock);
-	target = btrfs_get_restripe_target(fs_info, flags);
-	if (target) {
-		/* pick target profile only if it's already available */
-		if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
-			spin_unlock(&fs_info->balance_lock);
-			return extended_to_chunk(target);
-		}
-	}
-	spin_unlock(&fs_info->balance_lock);
-
-	/* First, mask out the RAID levels which aren't possible */
-	for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
-		if (num_devices >= btrfs_raid_array[raid_type].devs_min)
-			allowed |= btrfs_raid_array[raid_type].bg_flag;
-	}
-	allowed &= flags;
-
-	if (allowed & BTRFS_BLOCK_GROUP_RAID6)
-		allowed = BTRFS_BLOCK_GROUP_RAID6;
-	else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
-		allowed = BTRFS_BLOCK_GROUP_RAID5;
-	else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
-		allowed = BTRFS_BLOCK_GROUP_RAID10;
-	else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
-		allowed = BTRFS_BLOCK_GROUP_RAID1;
-	else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
-		allowed = BTRFS_BLOCK_GROUP_RAID0;
-
-	flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
-
-	return extended_to_chunk(flags | allowed);
-}
-
-u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
-{
-	unsigned seq;
-	u64 flags;
-
-	do {
-		flags = orig_flags;
-		seq = read_seqbegin(&fs_info->profiles_lock);
-
-		if (flags & BTRFS_BLOCK_GROUP_DATA)
-			flags |= fs_info->avail_data_alloc_bits;
-		else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-			flags |= fs_info->avail_system_alloc_bits;
-		else if (flags & BTRFS_BLOCK_GROUP_METADATA)
-			flags |= fs_info->avail_metadata_alloc_bits;
-	} while (read_seqretry(&fs_info->profiles_lock, seq));
-
-	return btrfs_reduce_alloc_profile(fs_info, flags);
-}
-
 static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -2641,21 +2541,6 @@ static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data)
 	return ret;
 }
 
-u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
-{
-	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
-}
-
-u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
-{
-	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
-}
-
-u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
-{
-	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
-}
-
 static u64 first_logical_byte(struct btrfs_fs_info *fs_info, u64 search_start)
 {
 	struct btrfs_block_group_cache *cache;
-- 
2.14.3

[PATCH 24/25] btrfs: migrate the block group cleanup code

[Josef Bacik]

This can now be easily migrated as well.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/block-group.h |   2 +
 fs/btrfs/ctree.h       |   2 -
 fs/btrfs/extent-tree.c | 140 -------------------------------------------------
 4 files changed, 142 insertions(+), 142 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 579073ec62c3..57ac375ae847 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -3167,3 +3167,143 @@ void check_system_chunk(struct btrfs_trans_handle *trans, u64 type)
 			trans->chunk_bytes_reserved += thresh;
 	}
 }
+
+void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
+{
+	struct btrfs_block_group_cache *block_group;
+	u64 last = 0;
+
+	while (1) {
+		struct inode *inode;
+
+		block_group = btrfs_lookup_first_block_group(info, last);
+		while (block_group) {
+			btrfs_wait_block_group_cache_done(block_group);
+			spin_lock(&block_group->lock);
+			if (block_group->iref)
+				break;
+			spin_unlock(&block_group->lock);
+			block_group = btrfs_next_block_group(block_group);
+		}
+		if (!block_group) {
+			if (last == 0)
+				break;
+			last = 0;
+			continue;
+		}
+
+		inode = block_group->inode;
+		block_group->iref = 0;
+		block_group->inode = NULL;
+		spin_unlock(&block_group->lock);
+		ASSERT(block_group->io_ctl.inode == NULL);
+		iput(inode);
+		last = block_group->key.objectid + block_group->key.offset;
+		btrfs_put_block_group(block_group);
+	}
+}
+
+/*
+ * Must be called only after stopping all workers, since we could have block
+ * group caching kthreads running, and therefore they could race with us if we
+ * freed the block groups before stopping them.
+ */
+int btrfs_free_block_groups(struct btrfs_fs_info *info)
+{
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_space_info *space_info;
+	struct btrfs_caching_control *caching_ctl;
+	struct rb_node *n;
+
+	down_write(&info->commit_root_sem);
+	while (!list_empty(&info->caching_block_groups)) {
+		caching_ctl = list_entry(info->caching_block_groups.next,
+					 struct btrfs_caching_control, list);
+		list_del(&caching_ctl->list);
+		btrfs_put_caching_control(caching_ctl);
+	}
+	up_write(&info->commit_root_sem);
+
+	spin_lock(&info->unused_bgs_lock);
+	while (!list_empty(&info->unused_bgs)) {
+		block_group = list_first_entry(&info->unused_bgs,
+					       struct btrfs_block_group_cache,
+					       bg_list);
+		list_del_init(&block_group->bg_list);
+		btrfs_put_block_group(block_group);
+	}
+	spin_unlock(&info->unused_bgs_lock);
+
+	spin_lock(&info->block_group_cache_lock);
+	while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
+		block_group = rb_entry(n, struct btrfs_block_group_cache,
+				       cache_node);
+		rb_erase(&block_group->cache_node,
+			 &info->block_group_cache_tree);
+		RB_CLEAR_NODE(&block_group->cache_node);
+		spin_unlock(&info->block_group_cache_lock);
+
+		down_write(&block_group->space_info->groups_sem);
+		list_del(&block_group->list);
+		up_write(&block_group->space_info->groups_sem);
+
+		/*
+		 * We haven't cached this block group, which means we could
+		 * possibly have excluded extents on this block group.
+		 */
+		if (block_group->cached == BTRFS_CACHE_NO ||
+		    block_group->cached == BTRFS_CACHE_ERROR)
+			btrfs_free_excluded_extents(block_group);
+
+		btrfs_remove_free_space_cache(block_group);
+		ASSERT(block_group->cached != BTRFS_CACHE_STARTED);
+		ASSERT(list_empty(&block_group->dirty_list));
+		ASSERT(list_empty(&block_group->io_list));
+		ASSERT(list_empty(&block_group->bg_list));
+		ASSERT(atomic_read(&block_group->count) == 1);
+		btrfs_put_block_group(block_group);
+
+		spin_lock(&info->block_group_cache_lock);
+	}
+	spin_unlock(&info->block_group_cache_lock);
+
+	/* now that all the block groups are freed, go through and
+	 * free all the space_info structs.  This is only called during
+	 * the final stages of unmount, and so we know nobody is
+	 * using them.  We call synchronize_rcu() once before we start,
+	 * just to be on the safe side.
+	 */
+	synchronize_rcu();
+
+	btrfs_release_global_block_rsv(info);
+
+	while (!list_empty(&info->space_info)) {
+		int i;
+
+		space_info = list_entry(info->space_info.next,
+					struct btrfs_space_info,
+					list);
+
+		/*
+		 * Do not hide this behind enospc_debug, this is actually
+		 * important and indicates a real bug if this happens.
+		 */
+		if (WARN_ON(space_info->bytes_pinned > 0 ||
+			    space_info->bytes_reserved > 0 ||
+			    space_info->bytes_may_use > 0))
+			btrfs_dump_space_info(info, space_info, 0, 0);
+		list_del(&space_info->list);
+		for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
+			struct kobject *kobj;
+			kobj = space_info->block_group_kobjs[i];
+			space_info->block_group_kobjs[i] = NULL;
+			if (kobj) {
+				kobject_del(kobj);
+				kobject_put(kobj);
+			}
+		}
+		kobject_del(&space_info->kobj);
+		kobject_put(&space_info->kobj);
+	}
+	return 0;
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 9f6ddb5c9fef..3c6cf7477990 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -228,6 +228,8 @@ int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
 u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
+void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
+int btrfs_free_block_groups(struct btrfs_fs_info *info);
 
 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
 {
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1d1872e93996..412cfda54e5e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2518,7 +2518,6 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 			 struct btrfs_ref *generic_ref);
 
 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr);
-int btrfs_free_block_groups(struct btrfs_fs_info *info);
 void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info);
 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *cache);
@@ -2556,7 +2555,6 @@ void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes,
 				    bool qgroup_free);
 
 int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes);
-void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
 				   u64 start, u64 end);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 53b164964b3b..82e4b62dc51b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5512,146 +5512,6 @@ u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
 	return free_bytes;
 }
 
-void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
-{
-	struct btrfs_block_group_cache *block_group;
-	u64 last = 0;
-
-	while (1) {
-		struct inode *inode;
-
-		block_group = btrfs_lookup_first_block_group(info, last);
-		while (block_group) {
-			btrfs_wait_block_group_cache_done(block_group);
-			spin_lock(&block_group->lock);
-			if (block_group->iref)
-				break;
-			spin_unlock(&block_group->lock);
-			block_group = btrfs_next_block_group(block_group);
-		}
-		if (!block_group) {
-			if (last == 0)
-				break;
-			last = 0;
-			continue;
-		}
-
-		inode = block_group->inode;
-		block_group->iref = 0;
-		block_group->inode = NULL;
-		spin_unlock(&block_group->lock);
-		ASSERT(block_group->io_ctl.inode == NULL);
-		iput(inode);
-		last = block_group->key.objectid + block_group->key.offset;
-		btrfs_put_block_group(block_group);
-	}
-}
-
-/*
- * Must be called only after stopping all workers, since we could have block
- * group caching kthreads running, and therefore they could race with us if we
- * freed the block groups before stopping them.
- */
-int btrfs_free_block_groups(struct btrfs_fs_info *info)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_space_info *space_info;
-	struct btrfs_caching_control *caching_ctl;
-	struct rb_node *n;
-
-	down_write(&info->commit_root_sem);
-	while (!list_empty(&info->caching_block_groups)) {
-		caching_ctl = list_entry(info->caching_block_groups.next,
-					 struct btrfs_caching_control, list);
-		list_del(&caching_ctl->list);
-		btrfs_put_caching_control(caching_ctl);
-	}
-	up_write(&info->commit_root_sem);
-
-	spin_lock(&info->unused_bgs_lock);
-	while (!list_empty(&info->unused_bgs)) {
-		block_group = list_first_entry(&info->unused_bgs,
-					       struct btrfs_block_group_cache,
-					       bg_list);
-		list_del_init(&block_group->bg_list);
-		btrfs_put_block_group(block_group);
-	}
-	spin_unlock(&info->unused_bgs_lock);
-
-	spin_lock(&info->block_group_cache_lock);
-	while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
-		block_group = rb_entry(n, struct btrfs_block_group_cache,
-				       cache_node);
-		rb_erase(&block_group->cache_node,
-			 &info->block_group_cache_tree);
-		RB_CLEAR_NODE(&block_group->cache_node);
-		spin_unlock(&info->block_group_cache_lock);
-
-		down_write(&block_group->space_info->groups_sem);
-		list_del(&block_group->list);
-		up_write(&block_group->space_info->groups_sem);
-
-		/*
-		 * We haven't cached this block group, which means we could
-		 * possibly have excluded extents on this block group.
-		 */
-		if (block_group->cached == BTRFS_CACHE_NO ||
-		    block_group->cached == BTRFS_CACHE_ERROR)
-			btrfs_free_excluded_extents(block_group);
-
-		btrfs_remove_free_space_cache(block_group);
-		ASSERT(block_group->cached != BTRFS_CACHE_STARTED);
-		ASSERT(list_empty(&block_group->dirty_list));
-		ASSERT(list_empty(&block_group->io_list));
-		ASSERT(list_empty(&block_group->bg_list));
-		ASSERT(atomic_read(&block_group->count) == 1);
-		btrfs_put_block_group(block_group);
-
-		spin_lock(&info->block_group_cache_lock);
-	}
-	spin_unlock(&info->block_group_cache_lock);
-
-	/* now that all the block groups are freed, go through and
-	 * free all the space_info structs.  This is only called during
-	 * the final stages of unmount, and so we know nobody is
-	 * using them.  We call synchronize_rcu() once before we start,
-	 * just to be on the safe side.
-	 */
-	synchronize_rcu();
-
-	btrfs_release_global_block_rsv(info);
-
-	while (!list_empty(&info->space_info)) {
-		int i;
-
-		space_info = list_entry(info->space_info.next,
-					struct btrfs_space_info,
-					list);
-
-		/*
-		 * Do not hide this behind enospc_debug, this is actually
-		 * important and indicates a real bug if this happens.
-		 */
-		if (WARN_ON(space_info->bytes_pinned > 0 ||
-			    space_info->bytes_reserved > 0 ||
-			    space_info->bytes_may_use > 0))
-			btrfs_dump_space_info(info, space_info, 0, 0);
-		list_del(&space_info->list);
-		for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
-			struct kobject *kobj;
-			kobj = space_info->block_group_kobjs[i];
-			space_info->block_group_kobjs[i] = NULL;
-			if (kobj) {
-				kobject_del(kobj);
-				kobject_put(kobj);
-			}
-		}
-		kobject_del(&space_info->kobj);
-		kobject_put(&space_info->kobj);
-	}
-	return 0;
-}
-
 /* link_block_group will queue up kobjects to add when we're reclaim-safe */
 void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info)
 {
-- 
2.14.3

[PATCH 25/25] btrfs: unexport the temporary exported functions

[Josef Bacik]

These were renamed and exported to facilitate logical migration of
different code chunks into block-group.c.  Now that all the users are in
one file go ahead and rename them back, move the code around, and make
them static.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.c | 140 ++++++++++++++++++++++++-------------------------
 fs/btrfs/block-group.h |   6 ---
 2 files changed, 70 insertions(+), 76 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 57ac375ae847..add34cbf76b8 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -23,7 +23,7 @@
  *
  * should be called with balance_lock held
  */
-u64 btrfs_get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
+static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
 {
 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
 	u64 target = 0;
@@ -64,7 +64,7 @@ static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
 	 * try to reduce to the target profile
 	 */
 	spin_lock(&fs_info->balance_lock);
-	target = btrfs_get_restripe_target(fs_info, flags);
+	target = get_restripe_target(fs_info, flags);
 	if (target) {
 		/* pick target profile only if it's already available */
 		if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
@@ -426,7 +426,7 @@ int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
 }
 
 #ifdef CONFIG_BTRFS_DEBUG
-void btrfs_fragment_free_space(struct btrfs_block_group_cache *block_group)
+static void fragment_free_space(struct btrfs_block_group_cache *block_group)
 {
 	struct btrfs_fs_info *fs_info = block_group->fs_info;
 	u64 start = block_group->key.objectid;
@@ -664,7 +664,7 @@ static noinline void caching_thread(struct btrfs_work *work)
 		block_group->space_info->bytes_used += bytes_used >> 1;
 		spin_unlock(&block_group->lock);
 		spin_unlock(&block_group->space_info->lock);
-		btrfs_fragment_free_space(block_group);
+		fragment_free_space(block_group);
 	}
 #endif
 
@@ -771,7 +771,7 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 			cache->space_info->bytes_used += bytes_used >> 1;
 			spin_unlock(&cache->lock);
 			spin_unlock(&cache->space_info->lock);
-			btrfs_fragment_free_space(cache);
+			fragment_free_space(cache);
 		}
 #endif
 		mutex_unlock(&caching_ctl->mutex);
@@ -1139,6 +1139,62 @@ btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info,
 							   num_items, 1);
 }
 
+static int inc_block_group_ro(struct btrfs_block_group_cache *cache,
+			      int force)
+{
+	struct btrfs_space_info *sinfo = cache->space_info;
+	u64 num_bytes;
+	u64 sinfo_used;
+	u64 min_allocable_bytes;
+	int ret = -ENOSPC;
+
+	/*
+	 * We need some metadata space and system metadata space for
+	 * allocating chunks in some corner cases until we force to set
+	 * it to be readonly.
+	 */
+	if ((sinfo->flags &
+	     (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
+	    !force)
+		min_allocable_bytes = SZ_1M;
+	else
+		min_allocable_bytes = 0;
+
+	spin_lock(&sinfo->lock);
+	spin_lock(&cache->lock);
+
+	if (cache->ro) {
+		cache->ro++;
+		ret = 0;
+		goto out;
+	}
+
+	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
+		    cache->bytes_super - btrfs_block_group_used(&cache->item);
+	sinfo_used = btrfs_space_info_used(sinfo, true);
+
+	if (sinfo_used + num_bytes + min_allocable_bytes <=
+	    sinfo->total_bytes) {
+		sinfo->bytes_readonly += num_bytes;
+		cache->ro++;
+		list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
+		ret = 0;
+	}
+out:
+	spin_unlock(&cache->lock);
+	spin_unlock(&sinfo->lock);
+	if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) {
+		btrfs_info(cache->fs_info,
+			"unable to make block group %llu ro",
+			cache->key.objectid);
+		btrfs_info(cache->fs_info,
+			"sinfo_used=%llu bg_num_bytes=%llu min_allocable=%llu",
+			sinfo_used, num_bytes, min_allocable_bytes);
+		btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0);
+	}
+	return ret;
+}
+
 /*
  * Process the unused_bgs list and remove any that don't have any allocated
  * space inside of them.
@@ -1194,7 +1250,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
 		spin_unlock(&block_group->lock);
 
 		/* We don't want to force the issue, only flip if it's ok. */
-		ret = __btrfs_inc_block_group_ro(block_group, 0);
+		ret = inc_block_group_ro(block_group, 0);
 		up_write(&space_info->groups_sem);
 		if (ret < 0) {
 			ret = 0;
@@ -1736,7 +1792,7 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
 
 		set_avail_alloc_bits(info, cache->flags);
 		if (btrfs_chunk_readonly(info, cache->key.objectid)) {
-			__btrfs_inc_block_group_ro(cache, 1);
+			inc_block_group_ro(cache, 1);
 		} else if (btrfs_block_group_used(&cache->item) == 0) {
 			ASSERT(list_empty(&cache->bg_list));
 			btrfs_mark_bg_unused(cache);
@@ -1758,11 +1814,11 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
 		list_for_each_entry(cache,
 				&space_info->block_groups[BTRFS_RAID_RAID0],
 				list)
-			__btrfs_inc_block_group_ro(cache, 1);
+			inc_block_group_ro(cache, 1);
 		list_for_each_entry(cache,
 				&space_info->block_groups[BTRFS_RAID_SINGLE],
 				list)
-			__btrfs_inc_block_group_ro(cache, 1);
+			inc_block_group_ro(cache, 1);
 	}
 
 	btrfs_add_raid_kobjects(info);
@@ -1855,7 +1911,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 		u64 new_bytes_used = size - bytes_used;
 
 		bytes_used += new_bytes_used >> 1;
-		btrfs_fragment_free_space(cache);
+		fragment_free_space(cache);
 	}
 #endif
 	/*
@@ -1901,7 +1957,7 @@ static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
 	 * if restripe for this chunk_type is on pick target profile and
 	 * return, otherwise do the usual balance
 	 */
-	stripped = btrfs_get_restripe_target(fs_info, flags);
+	stripped = get_restripe_target(fs_info, flags);
 	if (stripped)
 		return extended_to_chunk(stripped);
 
@@ -1941,62 +1997,6 @@ static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
 	return flags;
 }
 
-int __btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache,
-			       int force)
-{
-	struct btrfs_space_info *sinfo = cache->space_info;
-	u64 num_bytes;
-	u64 sinfo_used;
-	u64 min_allocable_bytes;
-	int ret = -ENOSPC;
-
-	/*
-	 * We need some metadata space and system metadata space for
-	 * allocating chunks in some corner cases until we force to set
-	 * it to be readonly.
-	 */
-	if ((sinfo->flags &
-	     (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
-	    !force)
-		min_allocable_bytes = SZ_1M;
-	else
-		min_allocable_bytes = 0;
-
-	spin_lock(&sinfo->lock);
-	spin_lock(&cache->lock);
-
-	if (cache->ro) {
-		cache->ro++;
-		ret = 0;
-		goto out;
-	}
-
-	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
-		    cache->bytes_super - btrfs_block_group_used(&cache->item);
-	sinfo_used = btrfs_space_info_used(sinfo, true);
-
-	if (sinfo_used + num_bytes + min_allocable_bytes <=
-	    sinfo->total_bytes) {
-		sinfo->bytes_readonly += num_bytes;
-		cache->ro++;
-		list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
-		ret = 0;
-	}
-out:
-	spin_unlock(&cache->lock);
-	spin_unlock(&sinfo->lock);
-	if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) {
-		btrfs_info(cache->fs_info,
-			"unable to make block group %llu ro",
-			cache->key.objectid);
-		btrfs_info(cache->fs_info,
-			"sinfo_used=%llu bg_num_bytes=%llu min_allocable=%llu",
-			sinfo_used, num_bytes, min_allocable_bytes);
-		btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0);
-	}
-	return ret;
-}
-
 int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
 
 {
@@ -2047,14 +2047,14 @@ int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
 			goto out;
 	}
 
-	ret = __btrfs_inc_block_group_ro(cache, 0);
+	ret = inc_block_group_ro(cache, 0);
 	if (!ret)
 		goto out;
 	alloc_flags = btrfs_get_alloc_profile(fs_info, cache->space_info->flags);
 	ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
 	if (ret < 0)
 		goto out;
-	ret = __btrfs_inc_block_group_ro(cache, 0);
+	ret = inc_block_group_ro(cache, 0);
 out:
 	if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
 		alloc_flags = update_block_group_flags(fs_info, cache->flags);
@@ -2858,7 +2858,7 @@ int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr)
 	 *      3: raid0
 	 *      4: single
 	 */
-	target = btrfs_get_restripe_target(fs_info, block_group->flags);
+	target = get_restripe_target(fs_info, block_group->flags);
 	if (target) {
 		index = btrfs_bg_flags_to_raid_index(extended_to_chunk(target));
 	} else {
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 3c6cf7477990..bf72dcfc1c82 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -171,7 +171,6 @@ btrfs_should_fragment_free_space(struct btrfs_block_group_cache *block_group)
 	       (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
 		block_group->flags &  BTRFS_BLOCK_GROUP_DATA);
 }
-void btrfs_fragment_free_space(struct btrfs_block_group_cache *block_group);
 #endif
 
 struct btrfs_block_group_cache *
@@ -253,9 +252,4 @@ btrfs_block_group_cache_done(struct btrfs_block_group_cache *cache)
 	return cache->cached == BTRFS_CACHE_FINISHED ||
 		cache->cached == BTRFS_CACHE_ERROR;
 }
-
-int __btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache,
-			       int force);
-u64 btrfs_get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags);
-
 #endif /* BTRFS_BLOCK_GROUP_H */
-- 
2.14.3

Re: [PATCH 00/25] btrfs: migrate the block group code

[David Sterba]

On Thu, Jun 20, 2019 at 03:37:42PM -0400, Josef Bacik wrote:
> This is the series to migrate the block group code out of extent-tree.c.  This
> is a much larger series than the previous two series because things were much
> more intertwined than block_rsv's and space_info.  There is one code change
> patch in this series, it is
> 
> btrfs: make caching_thread use btrfs_find_next_key

I've merged 1-10 (ie. up to the patch mentioned above) as it applied
cleanly on current misc-next, the rest produced some conflicts.

Although most of the code is moving from a file to file, I fixed the
coding style as this is the perfect opportunity to update code that does
not change often.

If you're going to send more patchsets like that, please do another pass
after copy&paste of the code. Also note that the SPDX header in new .c
files uses the weird // comments, unlike headers that use /* */ .

Re: [PATCH 00/25] btrfs: migrate the block group code

[Josef Bacik]

On Fri, Aug 02, 2019 at 03:56:38PM +0200, David Sterba wrote:
> On Thu, Jun 20, 2019 at 03:37:42PM -0400, Josef Bacik wrote:
> > This is the series to migrate the block group code out of extent-tree.c.  This
> > is a much larger series than the previous two series because things were much
> > more intertwined than block_rsv's and space_info.  There is one code change
> > patch in this series, it is
> > 
> > btrfs: make caching_thread use btrfs_find_next_key
> 
> I've merged 1-10 (ie. up to the patch mentioned above) as it applied
> cleanly on current misc-next, the rest produced some conflicts.
> 
> Although most of the code is moving from a file to file, I fixed the
> coding style as this is the perfect opportunity to update code that does
> not change often.
> 
> If you're going to send more patchsets like that, please do another pass
> after copy&paste of the code. Also note that the SPDX header in new .c
> files uses the weird // comments, unlike headers that use /* */ .

I'm working off of next-fixes on git.kernel.org, and it looks like you have all
my patches there.  Is there a different branch that I'm supposed to be working
off of?  Thanks,

Josef

Re: [PATCH 00/25] btrfs: migrate the block group code

[David Sterba]

On Fri, Aug 02, 2019 at 10:07:17AM -0400, Josef Bacik wrote:
> On Fri, Aug 02, 2019 at 03:56:38PM +0200, David Sterba wrote:
> > On Thu, Jun 20, 2019 at 03:37:42PM -0400, Josef Bacik wrote:
> > > This is the series to migrate the block group code out of extent-tree.c.  This
> > > is a much larger series than the previous two series because things were much
> > > more intertwined than block_rsv's and space_info.  There is one code change
> > > patch in this series, it is
> > > 
> > > btrfs: make caching_thread use btrfs_find_next_key
> > 
> > I've merged 1-10 (ie. up to the patch mentioned above) as it applied
> > cleanly on current misc-next, the rest produced some conflicts.
> > 
> > Although most of the code is moving from a file to file, I fixed the
> > coding style as this is the perfect opportunity to update code that does
> > not change often.
> > 
> > If you're going to send more patchsets like that, please do another pass
> > after copy&paste of the code. Also note that the SPDX header in new .c
> > files uses the weird // comments, unlike headers that use /* */ .
> 
> I'm working off of next-fixes on git.kernel.org, and it looks like you have all
> my patches there.  Is there a different branch that I'm supposed to be working
> off of?  Thanks,

The k.org tree should not be used for development, the branches are for
interaction with other trees like linux-next or sent to Linus.

The for-next is an integration branch, the development should be based
off either misc-next or eg. last rc to avoid conflicts.

Current misc-next contains only first 10 patches from this series, the
rest I'll process next week.

Re: [PATCH 00/25] btrfs: migrate the block group code

[David Sterba]

On Fri, Aug 02, 2019 at 03:56:38PM +0200, David Sterba wrote:
> On Thu, Jun 20, 2019 at 03:37:42PM -0400, Josef Bacik wrote:
> > This is the series to migrate the block group code out of extent-tree.c.  This
> > is a much larger series than the previous two series because things were much
> > more intertwined than block_rsv's and space_info.  There is one code change
> > patch in this series, it is
> > 
> > btrfs: make caching_thread use btrfs_find_next_key
> 
> I've merged 1-10 (ie. up to the patch mentioned above) as it applied
> cleanly on current misc-next, the rest produced some conflicts.

11-25 is now in testing and will be in misc-next soon.

I merged most of the patches manually, there were several updates (code
and coding style) in the moved code. As I don't want to do that painful
exercise again, patchsets like that must come last before the pull
request branch is frozen. This worked well with the other code moving
patchsets (3 patchsets, 23 patches in total).

This one alone has about the same amount of patches, which appears to
bee too much as the number of conflicts increases as other changes get
merged. So the recommended approach is to do that in smaller batches and
do next once the previous is merged.