[PATCH 00/21] Btrfs: restriper

[PATCH 00/21] Btrfs: restriper

[Ilya Dryomov]

Hello,

This is a respin of restriper patch series which adds an initial
implementation of restriper (it's a clever name for relocation framework
that allows to do selective profile changing and selective balancing
with some goodies like pausing/resuming and reporting progress to the
user).  See userspace cover patch for usage examples.

Changes from posted RFC include minor fixes to address received feedback
and some minor fixes of my own: improved inline comments, pause and
cancelling enhancements to eliminate race conditions, a better
validation of user input, some error reporting and error handling fixes.
Also I did s/restripe/balance to not introduce yet another term into
btrfs.  So nothing major, but the diff got quite large because of the
rename and some code movements.

The series is on top of 3.1 + for-linus, available at:

git://github.com/idryomov/btrfs-unstable.git restriper

Thanks,

		Ilya


Ilya Dryomov (21):
  Btrfs: get rid of *_alloc_profile fields
  Btrfs: introduce masks for chunk type and profile
  Btrfs: add BTRFS_AVAIL_ALLOC_BIT_SINGLE bit
  Btrfs: make avail_*_alloc_bits fields dynamic
  Btrfs: add basic restriper infrastructure
  Btrfs: add basic infrastructure for selective balancing
  Btrfs: profiles filter
  Btrfs: usage filter
  Btrfs: devid filter
  Btrfs: devid subset filter
  Btrfs: virtual address space subset filter
  Btrfs: do not reduce profile in do_chunk_alloc()
  Btrfs: implement online profile changing
  Btrfs: soft profile changing mode (aka soft convert)
  Btrfs: save balance parameters to disk
  Btrfs: recover balance on mount
  Btrfs: add skip_balance mount option
  Btrfs: allow for pausing restriper
  Btrfs: allow for cancelling restriper
  Btrfs: allow for resuming restriper after it was paused
  Btrfs: add balance progress reporting

 fs/btrfs/ctree.h       |  205 ++++++++++++-
 fs/btrfs/disk-io.c     |   18 +-
 fs/btrfs/extent-tree.c |  128 ++++++--
 fs/btrfs/ioctl.c       |  193 +++++++++++-
 fs/btrfs/ioctl.h       |   55 ++++
 fs/btrfs/super.c       |   11 +-
 fs/btrfs/volumes.c     |  803 +++++++++++++++++++++++++++++++++++++++++++++---
 fs/btrfs/volumes.h     |   50 +++-
 8 files changed, 1365 insertions(+), 98 deletions(-)

-- 
1.7.6.3

[PATCH 01/21] Btrfs: get rid of *_alloc_profile fields

[Ilya Dryomov]

{data,metadata,system}_alloc_profile fields have been unused for a long
time now.  Get rid of them.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ctree.h       |    3 ---
 fs/btrfs/disk-io.c     |    3 ---
 fs/btrfs/extent-tree.c |   10 ++++------
 fs/btrfs/volumes.c     |    6 ++----
 4 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6738503..f5434ad 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1135,9 +1135,6 @@ struct btrfs_fs_info {
 	u64 avail_data_alloc_bits;
 	u64 avail_metadata_alloc_bits;
 	u64 avail_system_alloc_bits;
-	u64 data_alloc_profile;
-	u64 metadata_alloc_profile;
-	u64 system_alloc_profile;
 
 	unsigned data_chunk_allocations;
 	unsigned metadata_ratio;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3f9d555..ce9d0fb 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2321,9 +2321,6 @@ retry_root_backup:
 
 	fs_info->generation = generation;
 	fs_info->last_trans_committed = generation;
-	fs_info->data_alloc_profile = (u64)-1;
-	fs_info->metadata_alloc_profile = (u64)-1;
-	fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
 
 	ret = btrfs_init_space_info(fs_info);
 	if (ret) {
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 8603ee4..f0591fd 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3067,14 +3067,12 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
 static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
 {
 	if (flags & BTRFS_BLOCK_GROUP_DATA)
-		flags |= root->fs_info->avail_data_alloc_bits &
-			 root->fs_info->data_alloc_profile;
+		flags |= root->fs_info->avail_data_alloc_bits;
 	else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-		flags |= root->fs_info->avail_system_alloc_bits &
-			 root->fs_info->system_alloc_profile;
+		flags |= root->fs_info->avail_system_alloc_bits;
 	else if (flags & BTRFS_BLOCK_GROUP_METADATA)
-		flags |= root->fs_info->avail_metadata_alloc_bits &
-			 root->fs_info->metadata_alloc_profile;
+		flags |= root->fs_info->avail_metadata_alloc_bits;
+
 	return btrfs_reduce_alloc_profile(root, flags);
 }
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f4b839f..89096f6 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2752,8 +2752,7 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
 		return ret;
 
 	alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
-			(fs_info->metadata_alloc_profile &
-			 fs_info->avail_metadata_alloc_bits);
+				fs_info->avail_metadata_alloc_bits;
 	alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
 
 	ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
@@ -2763,8 +2762,7 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
 	sys_chunk_offset = chunk_offset + chunk_size;
 
 	alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
-			(fs_info->system_alloc_profile &
-			 fs_info->avail_system_alloc_bits);
+				fs_info->avail_system_alloc_bits;
 	alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
 
 	ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
-- 
1.7.6.3

[PATCH 02/21] Btrfs: introduce masks for chunk type and profile

[Ilya Dryomov]

Chunk's type and profile are encoded in u64 flags field.  Introduce
masks to easily access them.  Also fix the type of BTRFS_BLOCK_GROUP_*
constants, it should be ULL.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ctree.h       |   26 +++++++++++++++++---------
 fs/btrfs/extent-tree.c |   12 +++---------
 fs/btrfs/volumes.c     |   11 ++---------
 3 files changed, 22 insertions(+), 27 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index f5434ad..4370a56 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -751,15 +751,23 @@ struct btrfs_csum_item {
 } __attribute__ ((__packed__));
 
 /* different types of block groups (and chunks) */
-#define BTRFS_BLOCK_GROUP_DATA     (1 << 0)
-#define BTRFS_BLOCK_GROUP_SYSTEM   (1 << 1)
-#define BTRFS_BLOCK_GROUP_METADATA (1 << 2)
-#define BTRFS_BLOCK_GROUP_RAID0    (1 << 3)
-#define BTRFS_BLOCK_GROUP_RAID1    (1 << 4)
-#define BTRFS_BLOCK_GROUP_DUP	   (1 << 5)
-#define BTRFS_BLOCK_GROUP_RAID10   (1 << 6)
-#define BTRFS_NR_RAID_TYPES	   5
-
+#define BTRFS_BLOCK_GROUP_DATA		(1ULL << 0)
+#define BTRFS_BLOCK_GROUP_SYSTEM	(1ULL << 1)
+#define BTRFS_BLOCK_GROUP_METADATA	(1ULL << 2)
+#define BTRFS_BLOCK_GROUP_RAID0		(1ULL << 3)
+#define BTRFS_BLOCK_GROUP_RAID1		(1ULL << 4)
+#define BTRFS_BLOCK_GROUP_DUP		(1ULL << 5)
+#define BTRFS_BLOCK_GROUP_RAID10	(1ULL << 6)
+#define BTRFS_NR_RAID_TYPES		5
+
+#define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
+					 BTRFS_BLOCK_GROUP_SYSTEM |  \
+					 BTRFS_BLOCK_GROUP_METADATA)
+
+#define BTRFS_BLOCK_GROUP_PROFILE_MASK	(BTRFS_BLOCK_GROUP_RAID0 |   \
+					 BTRFS_BLOCK_GROUP_RAID1 |   \
+					 BTRFS_BLOCK_GROUP_DUP |     \
+					 BTRFS_BLOCK_GROUP_RAID10)
 struct btrfs_block_group_item {
 	__le64 used;
 	__le64 chunk_objectid;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f0591fd..a8d8204 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -618,8 +618,7 @@ static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
 	struct list_head *head = &info->space_info;
 	struct btrfs_space_info *found;
 
-	flags &= BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_SYSTEM |
-		 BTRFS_BLOCK_GROUP_METADATA;
+	flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(found, head, list) {
@@ -2993,9 +2992,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
 		INIT_LIST_HEAD(&found->block_groups[i]);
 	init_rwsem(&found->groups_sem);
 	spin_lock_init(&found->lock);
-	found->flags = flags & (BTRFS_BLOCK_GROUP_DATA |
-				BTRFS_BLOCK_GROUP_SYSTEM |
-				BTRFS_BLOCK_GROUP_METADATA);
+	found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
 	found->total_bytes = total_bytes;
 	found->disk_total = total_bytes * factor;
 	found->bytes_used = bytes_used;
@@ -3016,10 +3013,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
 
 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
 {
-	u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
-				   BTRFS_BLOCK_GROUP_RAID1 |
-				   BTRFS_BLOCK_GROUP_RAID10 |
-				   BTRFS_BLOCK_GROUP_DUP);
+	u64 extra_flags = flags & BTRFS_BLOCK_GROUP_PROFILE_MASK;
 	if (extra_flags) {
 		if (flags & BTRFS_BLOCK_GROUP_DATA)
 			fs_info->avail_data_alloc_bits |= extra_flags;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 89096f6..d5fdee5 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2949,12 +2949,8 @@ again:
 		}
 	}
 	if (rw & REQ_DISCARD) {
-		if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
-				 BTRFS_BLOCK_GROUP_RAID1 |
-				 BTRFS_BLOCK_GROUP_DUP |
-				 BTRFS_BLOCK_GROUP_RAID10)) {
+		if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK)
 			stripes_required = map->num_stripes;
-		}
 	}
 	if (bbio_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
 	    stripes_allocated < stripes_required) {
@@ -2978,10 +2974,7 @@ again:
 
 	if (rw & REQ_DISCARD)
 		*length = min_t(u64, em->len - offset, *length);
-	else if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
-			      BTRFS_BLOCK_GROUP_RAID1 |
-			      BTRFS_BLOCK_GROUP_RAID10 |
-			      BTRFS_BLOCK_GROUP_DUP)) {
+	else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
 		/* we limit the length of each bio to what fits in a stripe */
 		*length = min_t(u64, em->len - offset,
 				map->stripe_len - stripe_offset);
-- 
1.7.6.3

[PATCH 03/21] Btrfs: add BTRFS_AVAIL_ALLOC_BIT_SINGLE bit

[Ilya Dryomov]

Right now on-disk BTRFS_BLOCK_GROUP_* profile bits are used for
avail_{data,metadata,system}_alloc_bits fields, which gather info about
available allocation profiles in the FS.  When chunk is created or read
from disk, its profile is OR'ed with the corresponding avail_alloc_bits
field.  Since SINGLE is denoted by 0 in the on-disk format, currently
there is no way to tell when such chunks become avaialble.  Restriper
needs that information, so add a separate bit for SINGLE profile.

This bit is going to be in-memory only, it should never be written out
to disk, so it's not a disk format change.  However to avoid remappings
in future, reserve corresponding on-disk bit.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ctree.h       |   15 +++++++++++++++
 fs/btrfs/extent-tree.c |   30 +++++++++++++++++++++---------
 2 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 4370a56..3f8f11e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -758,6 +758,7 @@ struct btrfs_csum_item {
 #define BTRFS_BLOCK_GROUP_RAID1		(1ULL << 4)
 #define BTRFS_BLOCK_GROUP_DUP		(1ULL << 5)
 #define BTRFS_BLOCK_GROUP_RAID10	(1ULL << 6)
+#define BTRFS_BLOCK_GROUP_RESERVED	BTRFS_AVAIL_ALLOC_BIT_SINGLE
 #define BTRFS_NR_RAID_TYPES		5
 
 #define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
@@ -768,6 +769,15 @@ struct btrfs_csum_item {
 					 BTRFS_BLOCK_GROUP_RAID1 |   \
 					 BTRFS_BLOCK_GROUP_DUP |     \
 					 BTRFS_BLOCK_GROUP_RAID10)
+/*
+ * We need a bit for restriper to be able to tell when chunks of type
+ * SINGLE are available.  This "extended" profile format is used in
+ * fs_info->avail_*_alloc_bits (in-memory) and balance item fields
+ * (on-disk).  The corresponding on-disk bit in chunk.type is reserved
+ * to avoid remappings between two formats in future.
+ */
+#define BTRFS_AVAIL_ALLOC_BIT_SINGLE	(1ULL << 48)
+
 struct btrfs_block_group_item {
 	__le64 used;
 	__le64 chunk_objectid;
@@ -1140,6 +1150,11 @@ struct btrfs_fs_info {
 	spinlock_t ref_cache_lock;
 	u64 total_ref_cache_size;
 
+	/*
+	 * these three are in extended format (availability of single
+	 * chunks is denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE bit, other
+	 * types are denoted by corresponding BTRFS_BLOCK_GROUP_* bits)
+	 */
 	u64 avail_data_alloc_bits;
 	u64 avail_metadata_alloc_bits;
 	u64 avail_system_alloc_bits;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a8d8204..15a2294 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3014,16 +3014,24 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
 {
 	u64 extra_flags = flags & BTRFS_BLOCK_GROUP_PROFILE_MASK;
-	if (extra_flags) {
-		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;
-	}
+
+	/* chunk -> extended profile */
+	if (extra_flags == 0)
+		extra_flags = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+
+	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;
 }
 
+/*
+ * @flags: available profiles in extended format (see ctree.h)
+ *
+ * Returns reduced profile in chunk format.
+ */
 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
 {
 	/*
@@ -3053,8 +3061,12 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
 	if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
 	    ((flags & BTRFS_BLOCK_GROUP_RAID1) |
 	     (flags & BTRFS_BLOCK_GROUP_RAID10) |
-	     (flags & BTRFS_BLOCK_GROUP_DUP)))
+	     (flags & BTRFS_BLOCK_GROUP_DUP))) {
 		flags &= ~BTRFS_BLOCK_GROUP_RAID0;
+	}
+
+	/* extended -> chunk profile */
+	flags &= ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
 	return flags;
 }
 
-- 
1.7.6.3

[PATCH 04/21] Btrfs: make avail_*_alloc_bits fields dynamic

[Ilya Dryomov]

Currently when new chunks are created respective avail_alloc_bits field
is updated to reflect profiles of all chunks present in the system.
However when chunks are removed profile bits are never cleared.

This patch clears profile bit of respective avail_alloc_bits field when
the last chunk with that profile is removed.  Restriper needs this to
properly operate when "downgrading".

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/extent-tree.c |   20 ++++++++++++++++++++
 1 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 15a2294..946b067 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7469,6 +7469,22 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
 	return 0;
 }
 
+static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	u64 extra_flags = flags & BTRFS_BLOCK_GROUP_PROFILE_MASK;
+
+	/* chunk -> extended profile */
+	if (extra_flags == 0)
+		extra_flags = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+
+	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;
+}
+
 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root, u64 group_start)
 {
@@ -7479,6 +7495,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	struct btrfs_key key;
 	struct inode *inode;
 	int ret;
+	int index;
 	int factor;
 
 	root = root->fs_info->extent_root;
@@ -7494,6 +7511,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	free_excluded_extents(root, block_group);
 
 	memcpy(&key, &block_group->key, sizeof(key));
+	index = get_block_group_index(block_group);
 	if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
 				  BTRFS_BLOCK_GROUP_RAID1 |
 				  BTRFS_BLOCK_GROUP_RAID10))
@@ -7568,6 +7586,8 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	 * 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]))
+		clear_avail_alloc_bits(root->fs_info, block_group->flags);
 	up_write(&block_group->space_info->groups_sem);
 
 	if (block_group->cached == BTRFS_CACHE_STARTED)
-- 
1.7.6.3

[PATCH 05/21] Btrfs: add basic restriper infrastructure

[Ilya Dryomov]

Add basic restriper infrastructure: extended balancing ioctl and all
related ioctl data structures, add data structure for tracking
restriper's state to fs_info, etc.  The semantics of the old balancing
ioctl are fully preserved.

Explicitly disallow any volume operations when balance is in progress.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ctree.h   |    6 +++
 fs/btrfs/disk-io.c |    4 ++
 fs/btrfs/ioctl.c   |  114 ++++++++++++++++++++++++++++++++++++++++++++-------
 fs/btrfs/ioctl.h   |   43 +++++++++++++++++++
 fs/btrfs/volumes.c |  113 ++++++++++++++++++++++++++++++++++++++++-----------
 fs/btrfs/volumes.h |   13 +++++-
 6 files changed, 252 insertions(+), 41 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3f8f11e..c4d98c8 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -934,6 +934,7 @@ struct btrfs_block_group_cache {
 struct reloc_control;
 struct btrfs_device;
 struct btrfs_fs_devices;
+struct btrfs_balance_control;
 struct btrfs_delayed_root;
 struct btrfs_fs_info {
 	u8 fsid[BTRFS_FSID_SIZE];
@@ -1159,6 +1160,11 @@ struct btrfs_fs_info {
 	u64 avail_metadata_alloc_bits;
 	u64 avail_system_alloc_bits;
 
+	/* restriper state */
+	spinlock_t balance_lock;
+	struct mutex balance_mutex;
+	struct btrfs_balance_control *balance_ctl;
+
 	unsigned data_chunk_allocations;
 	unsigned metadata_ratio;
 
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ce9d0fb..190a1b2 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2002,6 +2002,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	init_rwsem(&fs_info->scrub_super_lock);
 	fs_info->scrub_workers_refcnt = 0;
 
+	spin_lock_init(&fs_info->balance_lock);
+	mutex_init(&fs_info->balance_mutex);
+	fs_info->balance_ctl = NULL;
+
 	sb->s_blocksize = 4096;
 	sb->s_blocksize_bits = blksize_bits(4096);
 	sb->s_bdi = &fs_info->bdi;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index c04f02c..221bae0 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1203,13 +1203,21 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	mutex_lock(&root->fs_info->volume_mutex);
+	if (root->fs_info->balance_ctl) {
+		printk(KERN_INFO "btrfs: balance in progress\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
 	vol_args = memdup_user(arg, sizeof(*vol_args));
-	if (IS_ERR(vol_args))
-		return PTR_ERR(vol_args);
+	if (IS_ERR(vol_args)) {
+		ret = PTR_ERR(vol_args);
+		goto out;
+	}
 
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 
-	mutex_lock(&root->fs_info->volume_mutex);
 	sizestr = vol_args->name;
 	devstr = strchr(sizestr, ':');
 	if (devstr) {
@@ -1226,7 +1234,7 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 		printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
 		       (unsigned long long)devid);
 		ret = -EINVAL;
-		goto out_unlock;
+		goto out_free;
 	}
 	if (!strcmp(sizestr, "max"))
 		new_size = device->bdev->bd_inode->i_size;
@@ -1241,7 +1249,7 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 		new_size = memparse(sizestr, NULL);
 		if (new_size == 0) {
 			ret = -EINVAL;
-			goto out_unlock;
+			goto out_free;
 		}
 	}
 
@@ -1250,7 +1258,7 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 	if (mod < 0) {
 		if (new_size > old_size) {
 			ret = -EINVAL;
-			goto out_unlock;
+			goto out_free;
 		}
 		new_size = old_size - new_size;
 	} else if (mod > 0) {
@@ -1259,11 +1267,11 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 
 	if (new_size < 256 * 1024 * 1024) {
 		ret = -EINVAL;
-		goto out_unlock;
+		goto out_free;
 	}
 	if (new_size > device->bdev->bd_inode->i_size) {
 		ret = -EFBIG;
-		goto out_unlock;
+		goto out_free;
 	}
 
 	do_div(new_size, root->sectorsize);
@@ -1276,7 +1284,7 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 		trans = btrfs_start_transaction(root, 0);
 		if (IS_ERR(trans)) {
 			ret = PTR_ERR(trans);
-			goto out_unlock;
+			goto out_free;
 		}
 		ret = btrfs_grow_device(trans, device, new_size);
 		btrfs_commit_transaction(trans, root);
@@ -1284,9 +1292,10 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 		ret = btrfs_shrink_device(device, new_size);
 	}
 
-out_unlock:
-	mutex_unlock(&root->fs_info->volume_mutex);
+out_free:
 	kfree(vol_args);
+out:
+	mutex_unlock(&root->fs_info->volume_mutex);
 	return ret;
 }
 
@@ -2052,14 +2061,25 @@ static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	mutex_lock(&root->fs_info->volume_mutex);
+	if (root->fs_info->balance_ctl) {
+		printk(KERN_INFO "btrfs: balance in progress\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
 	vol_args = memdup_user(arg, sizeof(*vol_args));
-	if (IS_ERR(vol_args))
-		return PTR_ERR(vol_args);
+	if (IS_ERR(vol_args)) {
+		ret = PTR_ERR(vol_args);
+		goto out;
+	}
 
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 	ret = btrfs_init_new_device(root, vol_args->name);
 
 	kfree(vol_args);
+out:
+	mutex_unlock(&root->fs_info->volume_mutex);
 	return ret;
 }
 
@@ -2074,14 +2094,25 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
 	if (root->fs_info->sb->s_flags & MS_RDONLY)
 		return -EROFS;
 
+	mutex_lock(&root->fs_info->volume_mutex);
+	if (root->fs_info->balance_ctl) {
+		printk(KERN_INFO "btrfs: balance in progress\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
 	vol_args = memdup_user(arg, sizeof(*vol_args));
-	if (IS_ERR(vol_args))
-		return PTR_ERR(vol_args);
+	if (IS_ERR(vol_args)) {
+		ret = PTR_ERR(vol_args);
+		goto out;
+	}
 
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 	ret = btrfs_rm_device(root, vol_args->name);
 
 	kfree(vol_args);
+out:
+	mutex_unlock(&root->fs_info->volume_mutex);
 	return ret;
 }
 
@@ -3034,6 +3065,55 @@ out:
 	return ret;
 }
 
+static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_ioctl_balance_args *bargs = NULL;
+	struct btrfs_balance_control *bctl;
+	int ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (fs_info->sb->s_flags & MS_RDONLY)
+		return -EROFS;
+
+	mutex_lock(&fs_info->volume_mutex);
+	mutex_lock(&fs_info->balance_mutex);
+
+	bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
+	if (!bctl) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	bctl->fs_info = fs_info;
+	if (arg) {
+		bargs = memdup_user(arg, sizeof(*bargs));
+		if (IS_ERR(bargs)) {
+			kfree(bctl);
+			ret = PTR_ERR(bargs);
+			goto out;
+		}
+
+		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
+		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
+		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
+
+		bctl->flags = bargs->flags;
+	}
+
+	ret = btrfs_balance(bctl, 0);
+	/*
+	 * bctl is freed in __cancel_balance
+	 */
+	kfree(bargs);
+out:
+	mutex_unlock(&fs_info->balance_mutex);
+	mutex_unlock(&fs_info->volume_mutex);
+	return ret;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
 		cmd, unsigned long arg)
 {
@@ -3078,7 +3158,7 @@ long btrfs_ioctl(struct file *file, unsigned int
 	case BTRFS_IOC_DEV_INFO:
 		return btrfs_ioctl_dev_info(root, argp);
 	case BTRFS_IOC_BALANCE:
-		return btrfs_balance(root->fs_info->dev_root);
+		return btrfs_ioctl_balance(root, NULL);
 	case BTRFS_IOC_CLONE:
 		return btrfs_ioctl_clone(file, arg, 0, 0, 0);
 	case BTRFS_IOC_CLONE_RANGE:
@@ -3110,6 +3190,8 @@ long btrfs_ioctl(struct file *file, unsigned int
 		return btrfs_ioctl_scrub_cancel(root, argp);
 	case BTRFS_IOC_SCRUB_PROGRESS:
 		return btrfs_ioctl_scrub_progress(root, argp);
+	case BTRFS_IOC_BALANCE_V2:
+		return btrfs_ioctl_balance(root, argp);
 	}
 
 	return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 252ae99..0ca8059 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -109,6 +109,47 @@ struct btrfs_ioctl_fs_info_args {
 	__u64 reserved[124];			/* pad to 1k */
 };
 
+/*
+ * this is packed, because it should be exactly the same as its disk
+ * byte order counterpart (struct btrfs_disk_balance_args)
+ */
+struct btrfs_balance_args {
+	__u64 profiles;
+	__u64 usage;
+	__u64 devid;
+	__u64 pstart;
+	__u64 pend;
+	__u64 vstart;
+	__u64 vend;
+
+	__u64 target;
+
+	__u64 flags;
+
+	__u64 unused[8];
+} __attribute__ ((__packed__));
+
+/* report balance progress to userspace */
+struct btrfs_balance_progress {
+	__u64 expected;		/* estimated # of chunks that will be
+				 * relocated to fulfill the request */
+	__u64 considered;	/* # of chunks we have considered so far */
+	__u64 completed;	/* # of chunks relocated so far */
+};
+
+struct btrfs_ioctl_balance_args {
+	__u64 flags;				/* in/out */
+	__u64 state;				/* out */
+
+	struct btrfs_balance_args data;		/* in/out */
+	struct btrfs_balance_args meta;		/* in/out */
+	struct btrfs_balance_args sys;		/* in/out */
+
+	struct btrfs_balance_progress stat;	/* out */
+
+	__u64 unused[72];			/* pad to 1k */
+};
+
 #define BTRFS_INO_LOOKUP_PATH_MAX 4080
 struct btrfs_ioctl_ino_lookup_args {
 	__u64 treeid;
@@ -272,6 +313,8 @@ struct btrfs_ioctl_logical_ino_args {
 				 struct btrfs_ioctl_dev_info_args)
 #define BTRFS_IOC_FS_INFO _IOR(BTRFS_IOCTL_MAGIC, 31, \
 			       struct btrfs_ioctl_fs_info_args)
+#define BTRFS_IOC_BALANCE_V2 _IOW(BTRFS_IOCTL_MAGIC, 32, \
+				  struct btrfs_ioctl_balance_args)
 #define BTRFS_IOC_INO_PATHS _IOWR(BTRFS_IOCTL_MAGIC, 35, \
 					struct btrfs_ioctl_ino_path_args)
 #define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d5fdee5..e8d6e78 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1282,7 +1282,6 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	bool clear_super = false;
 
 	mutex_lock(&uuid_mutex);
-	mutex_lock(&root->fs_info->volume_mutex);
 
 	all_avail = root->fs_info->avail_data_alloc_bits |
 		root->fs_info->avail_system_alloc_bits |
@@ -1452,7 +1451,6 @@ error_close:
 	if (bdev)
 		blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
 out:
-	mutex_unlock(&root->fs_info->volume_mutex);
 	mutex_unlock(&uuid_mutex);
 	return ret;
 error_undo:
@@ -1629,7 +1627,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	}
 
 	filemap_write_and_wait(bdev->bd_inode->i_mapping);
-	mutex_lock(&root->fs_info->volume_mutex);
 
 	devices = &root->fs_info->fs_devices->devices;
 	/*
@@ -1757,8 +1754,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 		ret = btrfs_relocate_sys_chunks(root);
 		BUG_ON(ret);
 	}
-out:
-	mutex_unlock(&root->fs_info->volume_mutex);
+
 	return ret;
 error:
 	blkdev_put(bdev, FMODE_EXCL);
@@ -1766,7 +1762,7 @@ error:
 		mutex_unlock(&uuid_mutex);
 		up_write(&sb->s_umount);
 	}
-	goto out;
+	return ret;
 }
 
 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
@@ -2077,6 +2073,35 @@ error:
 	return ret;
 }
 
+/*
+ * Should be called with both balance and volume mutexes held to
+ * serialize other volume operations (add_dev/rm_dev/resize) with
+ * restriper.  Same goes for unset_balance_control.
+ */
+static void set_balance_control(struct btrfs_balance_control *bctl)
+{
+	struct btrfs_fs_info *fs_info = bctl->fs_info;
+
+	BUG_ON(fs_info->balance_ctl);
+
+	spin_lock(&fs_info->balance_lock);
+	fs_info->balance_ctl = bctl;
+	spin_unlock(&fs_info->balance_lock);
+}
+
+static void unset_balance_control(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
+
+	BUG_ON(!fs_info->balance_ctl);
+
+	spin_lock(&fs_info->balance_lock);
+	fs_info->balance_ctl = NULL;
+	spin_unlock(&fs_info->balance_lock);
+
+	kfree(bctl);
+}
+
 static u64 div_factor(u64 num, int factor)
 {
 	if (factor == 10)
@@ -2086,29 +2111,23 @@ static u64 div_factor(u64 num, int factor)
 	return num;
 }
 
-int btrfs_balance(struct btrfs_root *dev_root)
+static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 {
-	int ret;
-	struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
+	struct btrfs_root *chunk_root = fs_info->chunk_root;
+	struct btrfs_root *dev_root = fs_info->dev_root;
+	struct list_head *devices;
 	struct btrfs_device *device;
 	u64 old_size;
 	u64 size_to_free;
 	struct btrfs_path *path;
 	struct btrfs_key key;
-	struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
-	struct btrfs_trans_handle *trans;
 	struct btrfs_key found_key;
-
-	if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
-		return -EROFS;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	mutex_lock(&dev_root->fs_info->volume_mutex);
-	dev_root = dev_root->fs_info->dev_root;
+	struct btrfs_trans_handle *trans;
+	int ret;
+	int enospc_errors = 0;
 
 	/* step one make some room on all the devices */
+	devices = &fs_info->fs_devices->devices;
 	list_for_each_entry(device, devices, dev_list) {
 		old_size = device->total_bytes;
 		size_to_free = div_factor(old_size, 1);
@@ -2151,12 +2170,12 @@ int btrfs_balance(struct btrfs_root *dev_root)
 		 * failed
 		 */
 		if (ret == 0)
-			break;
+			BUG(); /* FIXME break ? */
 
 		ret = btrfs_previous_item(chunk_root, path, 0,
 					  BTRFS_CHUNK_ITEM_KEY);
 		if (ret)
-			break;
+			BUG(); /* FIXME break ? */
 
 		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
 				      path->slots[0]);
@@ -2174,12 +2193,58 @@ int btrfs_balance(struct btrfs_root *dev_root)
 					   found_key.offset);
 		if (ret && ret != -ENOSPC)
 			goto error;
+		if (ret == -ENOSPC)
+			enospc_errors++;
 		key.offset = found_key.offset - 1;
 	}
-	ret = 0;
+
 error:
 	btrfs_free_path(path);
-	mutex_unlock(&dev_root->fs_info->volume_mutex);
+	if (enospc_errors) {
+		printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
+		       enospc_errors);
+		if (!ret)
+			ret = -ENOSPC;
+	}
+
+	return ret;
+}
+
+static void __cancel_balance(struct btrfs_fs_info *fs_info)
+{
+	unset_balance_control(fs_info);
+}
+
+/*
+ * Should be called with both balance and volume mutexes held
+ */
+int btrfs_balance(struct btrfs_balance_control *bctl, int resume)
+{
+	struct btrfs_fs_info *fs_info = bctl->fs_info;
+	int ret;
+
+	if (btrfs_fs_closing(fs_info)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (!resume)
+		set_balance_control(bctl);
+
+	mutex_unlock(&fs_info->balance_mutex);
+
+	ret = __btrfs_balance(fs_info);
+
+	mutex_lock(&fs_info->balance_mutex);
+
+	__cancel_balance(fs_info);
+
+	return ret;
+out:
+	if (resume)
+		__cancel_balance(fs_info);
+	else
+		kfree(bctl);
 	return ret;
 }
 
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 78f2d4d..b9daddc 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -186,6 +186,17 @@ struct map_lookup {
 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
 			    (sizeof(struct btrfs_bio_stripe) * (n)))
 
+struct btrfs_balance_args;
+struct btrfs_balance_control {
+	struct btrfs_fs_info *fs_info;
+
+	struct btrfs_balance_args data;
+	struct btrfs_balance_args meta;
+	struct btrfs_balance_args sys;
+
+	u64 flags;
+};
+
 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
 				   u64 end, u64 *length);
 
@@ -228,7 +239,7 @@ struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
 				       u8 *uuid, u8 *fsid);
 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 int btrfs_init_new_device(struct btrfs_root *root, char *path);
-int btrfs_balance(struct btrfs_root *dev_root);
+int btrfs_balance(struct btrfs_balance_control *rctl, int resume);
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 			 struct btrfs_device *device, u64 num_bytes,
-- 
1.7.6.3

[PATCH 06/21] Btrfs: add basic infrastructure for selective balancing

[Ilya Dryomov]

This allows to have a separate set of filters for each chunk type
(data,meta,sys).  The code however is generic and switch on chunk type
is only done once.

This commit also adds a type filter: it allows to balance for example
meta and system chunks w/o touching data ones.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ioctl.c   |    3 ++
 fs/btrfs/volumes.c |   58 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/volumes.h |   11 +++++++++
 3 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 221bae0..e20d0cb 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3101,6 +3101,9 @@ static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
 		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
 
 		bctl->flags = bargs->flags;
+	} else {
+		/* balance everything - no filters */
+		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
 	}
 
 	ret = btrfs_balance(bctl, 0);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e8d6e78..0e6cddd 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2102,6 +2102,30 @@ static void unset_balance_control(struct btrfs_fs_info *fs_info)
 	kfree(bctl);
 }
 
+static int should_balance_chunk(struct btrfs_root *root,
+				struct extent_buffer *leaf,
+				struct btrfs_chunk *chunk, u64 chunk_offset)
+{
+	struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
+	struct btrfs_balance_args *bargs = NULL;
+	u64 chunk_type = btrfs_chunk_type(leaf, chunk);
+
+	/* type filter */
+	if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
+	      (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
+		return 0;
+	}
+
+	if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
+		bargs = &bctl->data;
+	else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
+		bargs = &bctl->sys;
+	else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
+		bargs = &bctl->meta;
+
+	return 1;
+}
+
 static u64 div_factor(u64 num, int factor)
 {
 	if (factor == 10)
@@ -2119,10 +2143,13 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 	struct btrfs_device *device;
 	u64 old_size;
 	u64 size_to_free;
+	struct btrfs_chunk *chunk;
 	struct btrfs_path *path;
 	struct btrfs_key key;
 	struct btrfs_key found_key;
 	struct btrfs_trans_handle *trans;
+	struct extent_buffer *leaf;
+	int slot;
 	int ret;
 	int enospc_errors = 0;
 
@@ -2177,8 +2204,10 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 		if (ret)
 			BUG(); /* FIXME break ? */
 
-		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
-				      path->slots[0]);
+		leaf = path->nodes[0];
+		slot = path->slots[0];
+		btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
 		if (found_key.objectid != key.objectid)
 			break;
 
@@ -2186,7 +2215,14 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 		if (found_key.offset == 0)
 			break;
 
+		chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
+
+		ret = should_balance_chunk(chunk_root, leaf, chunk,
+					   found_key.offset);
 		btrfs_release_path(path);
+		if (!ret)
+			goto loop;
+
 		ret = btrfs_relocate_chunk(chunk_root,
 					   chunk_root->root_key.objectid,
 					   found_key.objectid,
@@ -2195,6 +2231,7 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 			goto error;
 		if (ret == -ENOSPC)
 			enospc_errors++;
+loop:
 		key.offset = found_key.offset - 1;
 	}
 
@@ -2221,11 +2258,28 @@ static void __cancel_balance(struct btrfs_fs_info *fs_info)
 int btrfs_balance(struct btrfs_balance_control *bctl, int resume)
 {
 	struct btrfs_fs_info *fs_info = bctl->fs_info;
+	u64 allowed;
 	int ret;
 
 	if (btrfs_fs_closing(fs_info)) {
 		ret = -EINVAL;
 		goto out;
+
+	/*
+	 * In case of mixed groups both data and meta should be picked,
+	 * and identical options should be given for both of them.
+	 */
+	allowed = btrfs_super_incompat_flags(fs_info->super_copy);
+	if ((allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
+	    (bctl->flags & (BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA))) {
+		if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
+		    !(bctl->flags & BTRFS_BALANCE_METADATA) ||
+		    memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
+			printk(KERN_ERR "btrfs: with mixed groups data and "
+			       "metadata balance options must be the same\n");
+			ret = -EINVAL;
+			goto out;
+		}
 	}
 
 	if (!resume)
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index b9daddc..7a78051 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -186,6 +186,17 @@ struct map_lookup {
 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
 			    (sizeof(struct btrfs_bio_stripe) * (n)))
 
+/*
+ * Restriper's general type filter
+ */
+#define BTRFS_BALANCE_DATA		(1ULL << 0)
+#define BTRFS_BALANCE_SYSTEM		(1ULL << 1)
+#define BTRFS_BALANCE_METADATA		(1ULL << 2)
+
+#define BTRFS_BALANCE_TYPE_MASK		(BTRFS_BALANCE_DATA |	    \
+					 BTRFS_BALANCE_SYSTEM |	    \
+					 BTRFS_BALANCE_METADATA)
+
 struct btrfs_balance_args;
 struct btrfs_balance_control {
 	struct btrfs_fs_info *fs_info;
-- 
1.7.6.3

[PATCH 07/21] Btrfs: profiles filter

[Ilya Dryomov]

Select chunks based on a given profile mask.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/volumes.c |   24 ++++++++++++++++++++++++
 fs/btrfs/volumes.h |    4 ++++
 2 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0e6cddd..315a6c2 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2102,6 +2102,24 @@ static void unset_balance_control(struct btrfs_fs_info *fs_info)
 	kfree(bctl);
 }
 
+/*
+ * Balance filters.  Return 1 if chunk should be filtered out
+ * (should not be balanced).
+ */
+static int chunk_profiles_filter(u64 chunk_profile,
+				 struct btrfs_balance_args *bargs)
+{
+	chunk_profile &= BTRFS_BLOCK_GROUP_PROFILE_MASK;
+
+	if (chunk_profile == 0)
+		chunk_profile = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+
+	if (bargs->profiles & chunk_profile)
+		return 0;
+
+	return 1;
+}
+
 static int should_balance_chunk(struct btrfs_root *root,
 				struct extent_buffer *leaf,
 				struct btrfs_chunk *chunk, u64 chunk_offset)
@@ -2123,6 +2141,12 @@ static int should_balance_chunk(struct btrfs_root *root,
 	else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
 		bargs = &bctl->meta;
 
+	/* profiles filter */
+	if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
+	    chunk_profiles_filter(chunk_type, bargs)) {
+		return 0;
+	}
+
 	return 1;
 }
 
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 7a78051..9c95c13 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -196,6 +196,10 @@ struct map_lookup {
 #define BTRFS_BALANCE_TYPE_MASK		(BTRFS_BALANCE_DATA |	    \
 					 BTRFS_BALANCE_SYSTEM |	    \
 					 BTRFS_BALANCE_METADATA)
+/*
+ * Balance filters
+ */
+#define BTRFS_BALANCE_ARGS_PROFILES	(1ULL << 0)
 
 struct btrfs_balance_args;
 struct btrfs_balance_control {
-- 
1.7.6.3

[PATCH 08/21] Btrfs: usage filter

[Ilya Dryomov]

Select chunks that are less than X percent full.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/volumes.c |   36 ++++++++++++++++++++++++++++++++++++
 fs/btrfs/volumes.h |    1 +
 2 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 315a6c2..e252cf2 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2120,6 +2120,36 @@ static int chunk_profiles_filter(u64 chunk_profile,
 	return 1;
 }
 
+static u64 div_factor_fine(u64 num, int factor)
+{
+	if (factor <= 0)
+		return 0;
+	if (factor >= 100)
+		return num;
+
+	num *= factor;
+	do_div(num, 100);
+	return num;
+}
+
+static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
+			      struct btrfs_balance_args *bargs)
+{
+	struct btrfs_block_group_cache *cache;
+	u64 chunk_used, user_thresh;
+	int ret = 1;
+
+	cache = btrfs_lookup_block_group(fs_info, chunk_offset);
+	chunk_used = btrfs_block_group_used(&cache->item);
+
+	user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
+	if (chunk_used < user_thresh)
+		ret = 0;
+
+	btrfs_put_block_group(cache);
+	return ret;
+}
+
 static int should_balance_chunk(struct btrfs_root *root,
 				struct extent_buffer *leaf,
 				struct btrfs_chunk *chunk, u64 chunk_offset)
@@ -2147,6 +2177,12 @@ static int should_balance_chunk(struct btrfs_root *root,
 		return 0;
 	}
 
+	/* usage filter */
+	if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
+	    chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
+		return 0;
+	}
+
 	return 1;
 }
 
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 9c95c13..23b53bb 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -200,6 +200,7 @@ struct map_lookup {
  * Balance filters
  */
 #define BTRFS_BALANCE_ARGS_PROFILES	(1ULL << 0)
+#define BTRFS_BALANCE_ARGS_USAGE	(1ULL << 1)
 
 struct btrfs_balance_args;
 struct btrfs_balance_control {
-- 
1.7.6.3

[PATCH 09/21] Btrfs: devid filter

[Ilya Dryomov]

Relocate chunks which have at least one stripe located on a device with
devid X.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/volumes.c |   23 +++++++++++++++++++++++
 fs/btrfs/volumes.h |    1 +
 2 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e252cf2..d52cfde 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2150,6 +2150,23 @@ static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
 	return ret;
 }
 
+static int chunk_devid_filter(struct extent_buffer *leaf,
+			      struct btrfs_chunk *chunk,
+			      struct btrfs_balance_args *bargs)
+{
+	struct btrfs_stripe *stripe;
+	int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+	int i;
+
+	for (i = 0; i < num_stripes; i++) {
+		stripe = btrfs_stripe_nr(chunk, i);
+		if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
+			return 0;
+	}
+
+	return 1;
+}
+
 static int should_balance_chunk(struct btrfs_root *root,
 				struct extent_buffer *leaf,
 				struct btrfs_chunk *chunk, u64 chunk_offset)
@@ -2183,6 +2200,12 @@ static int should_balance_chunk(struct btrfs_root *root,
 		return 0;
 	}
 
+	/* devid filter */
+	if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
+	    chunk_devid_filter(leaf, chunk, bargs)) {
+		return 0;
+	}
+
 	return 1;
 }
 
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 23b53bb..7007a31 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -201,6 +201,7 @@ struct map_lookup {
  */
 #define BTRFS_BALANCE_ARGS_PROFILES	(1ULL << 0)
 #define BTRFS_BALANCE_ARGS_USAGE	(1ULL << 1)
+#define BTRFS_BALANCE_ARGS_DEVID	(1ULL << 2)
 
 struct btrfs_balance_args;
 struct btrfs_balance_control {
-- 
1.7.6.3

[PATCH 10/21] Btrfs: devid subset filter

[Ilya Dryomov]

Select chunks which have at least one byte of at least one stripe
located on a device with devid X in a given [pstart,pend) physical
address range.

This filter only works when devid filter is turned on.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/volumes.c |   45 +++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/volumes.h |    1 +
 2 files changed, 46 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d52cfde..a5a2d65 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2167,6 +2167,45 @@ static int chunk_devid_filter(struct extent_buffer *leaf,
 	return 1;
 }
 
+/* [pstart, pend) */
+static int chunk_drange_filter(struct extent_buffer *leaf,
+			       struct btrfs_chunk *chunk,
+			       u64 chunk_offset,
+			       struct btrfs_balance_args *bargs)
+{
+	struct btrfs_stripe *stripe;
+	int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+	u64 stripe_offset;
+	u64 stripe_length;
+	int factor;
+	int i;
+
+	BUG_ON(!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID));
+
+	if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
+	     BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
+		factor = 2;
+	else
+		factor = 1;
+	factor = num_stripes / factor;
+
+	for (i = 0; i < num_stripes; i++) {
+		stripe = btrfs_stripe_nr(chunk, i);
+		if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
+			continue;
+
+		stripe_offset = btrfs_stripe_offset(leaf, stripe);
+		stripe_length = btrfs_chunk_length(leaf, chunk);
+		do_div(stripe_length, factor);
+
+		if (stripe_offset < bargs->pend &&
+		    stripe_offset + stripe_length > bargs->pstart)
+			return 0;
+	}
+
+	return 1;
+}
+
 static int should_balance_chunk(struct btrfs_root *root,
 				struct extent_buffer *leaf,
 				struct btrfs_chunk *chunk, u64 chunk_offset)
@@ -2206,6 +2245,12 @@ static int should_balance_chunk(struct btrfs_root *root,
 		return 0;
 	}
 
+	/* drange filter, makes sense only with devid filter */
+	if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
+	    chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
+		return 0;
+	}
+
 	return 1;
 }
 
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 7007a31..75fb5f2 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -202,6 +202,7 @@ struct map_lookup {
 #define BTRFS_BALANCE_ARGS_PROFILES	(1ULL << 0)
 #define BTRFS_BALANCE_ARGS_USAGE	(1ULL << 1)
 #define BTRFS_BALANCE_ARGS_DEVID	(1ULL << 2)
+#define BTRFS_BALANCE_ARGS_DRANGE	(1ULL << 3)
 
 struct btrfs_balance_args;
 struct btrfs_balance_control {
-- 
1.7.6.3

[PATCH 11/21] Btrfs: virtual address space subset filter

[Ilya Dryomov]

Select chunks which have at least one byte located inside a given
[vstart, vend) virtual address space range.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/volumes.c |   20 ++++++++++++++++++++
 fs/btrfs/volumes.h |    1 +
 2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a5a2d65..719e61d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2206,6 +2206,20 @@ static int chunk_drange_filter(struct extent_buffer *leaf,
 	return 1;
 }
 
+/* [vstart, vend) */
+static int chunk_vrange_filter(struct extent_buffer *leaf,
+			       struct btrfs_chunk *chunk,
+			       u64 chunk_offset,
+			       struct btrfs_balance_args *bargs)
+{
+	if (chunk_offset < bargs->vend &&
+	    chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
+		/* at least part of the chunk is inside this vrange */
+		return 0;
+
+	return 1;
+}
+
 static int should_balance_chunk(struct btrfs_root *root,
 				struct extent_buffer *leaf,
 				struct btrfs_chunk *chunk, u64 chunk_offset)
@@ -2251,6 +2265,12 @@ static int should_balance_chunk(struct btrfs_root *root,
 		return 0;
 	}
 
+	/* vrange filter */
+	if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
+	    chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
+		return 0;
+	}
+
 	return 1;
 }
 
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 75fb5f2..879afcb 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -203,6 +203,7 @@ struct map_lookup {
 #define BTRFS_BALANCE_ARGS_USAGE	(1ULL << 1)
 #define BTRFS_BALANCE_ARGS_DEVID	(1ULL << 2)
 #define BTRFS_BALANCE_ARGS_DRANGE	(1ULL << 3)
+#define BTRFS_BALANCE_ARGS_VRANGE	(1ULL << 4)
 
 struct btrfs_balance_args;
 struct btrfs_balance_control {
-- 
1.7.6.3

[PATCH 12/21] Btrfs: do not reduce profile in do_chunk_alloc()

[Ilya Dryomov]

Every caller of do_chunk_alloc() feeds it the reduced allocation
profile, so stop trying to reduce it one more time.  Instead check the
validity of the passed profile.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ctree.h       |   18 ++++++++++++++++++
 fs/btrfs/extent-tree.c |    2 +-
 2 files changed, 19 insertions(+), 1 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index c4d98c8..1e7aea6 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2536,6 +2536,24 @@ static inline void free_fs_info(struct btrfs_fs_info *fs_info)
 	kfree(fs_info->super_for_commit);
 	kfree(fs_info);
 }
+/**
+ * profile_is_valid - tests whether a given profile is valid and reduced
+ * @flags: profile to validate
+ * @extended: if true @flags is treated as an extended profile
+ */
+static inline int profile_is_valid(u64 flags, int extended)
+{
+	u64 mask = ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
+
+	flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
+	if (extended)
+		mask &= ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+
+	if (flags & mask)
+		return 0;
+	/* true if zero or exactly one bit set */
+	return (flags & (~flags + 1)) == flags;
+}
 
 /* root-item.c */
 int btrfs_find_root_ref(struct btrfs_root *tree_root,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 946b067..a1a18ea 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3295,7 +3295,7 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans,
 	int wait_for_alloc = 0;
 	int ret = 0;
 
-	flags = btrfs_reduce_alloc_profile(extent_root, flags);
+	BUG_ON(!profile_is_valid(flags, 0));
 
 	space_info = __find_space_info(extent_root->fs_info, flags);
 	if (!space_info) {
-- 
1.7.6.3

[PATCH 13/21] Btrfs: implement online profile changing

[Ilya Dryomov]

Profile changing is done by launching a balance with
BTRFS_BALANCE_CONVERT bits set and target fields of respective
btrfs_balance_args structs initialized.  Profile reducing code in this
case will pick restriper's target profile if it's available instead of
doing a blind reduce.  If target profile is not yet available it goes
back to a plain reduce.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/extent-tree.c |   56 ++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/volumes.c     |   69 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/volumes.h     |    5 +++
 3 files changed, 129 insertions(+), 1 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a1a18ea..e6a832e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3030,7 +3030,9 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
 /*
  * @flags: available profiles in extended format (see ctree.h)
  *
- * Returns reduced profile in chunk format.
+ * 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.
  */
 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
 {
@@ -3042,6 +3044,34 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
 	u64 num_devices = root->fs_info->fs_devices->rw_devices +
 		root->fs_info->fs_devices->missing_devices;
 
+	/* pick restriper's target profile if it's available */
+	spin_lock(&root->fs_info->balance_lock);
+	if (root->fs_info->balance_ctl) {
+		struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
+		u64 tgt = 0;
+
+		if ((flags & BTRFS_BLOCK_GROUP_DATA) &&
+		    (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+		    (flags & bctl->data.target)) {
+			tgt = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
+		} else if ((flags & BTRFS_BLOCK_GROUP_SYSTEM) &&
+			   (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+			   (flags & bctl->sys.target)) {
+			tgt = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
+		} else if ((flags & BTRFS_BLOCK_GROUP_METADATA) &&
+			   (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+			   (flags & bctl->meta.target)) {
+			tgt = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
+		}
+
+		if (tgt) {
+			spin_unlock(&root->fs_info->balance_lock);
+			flags = tgt;
+			goto out;
+		}
+	}
+	spin_unlock(&root->fs_info->balance_lock);
+
 	if (num_devices == 1)
 		flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
 	if (num_devices < 4)
@@ -3065,6 +3095,7 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
 		flags &= ~BTRFS_BLOCK_GROUP_RAID0;
 	}
 
+out:
 	/* extended -> chunk profile */
 	flags &= ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
 	return flags;
@@ -6795,6 +6826,29 @@ static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
 	u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
 		BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
 
+	if (root->fs_info->balance_ctl) {
+		struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
+		u64 tgt = 0;
+
+		/* pick restriper's target profile and return */
+		if (flags & BTRFS_BLOCK_GROUP_DATA &&
+		    bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+			tgt = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
+		} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
+			   bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+			tgt = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
+		} else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
+			   bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+			tgt = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
+		}
+
+		if (tgt) {
+			/* extended -> chunk profile */
+			tgt &= ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+			return tgt;
+		}
+	}
+
 	/*
 	 * we add in the count of missing devices because we want
 	 * to make sure that any RAID levels on a degraded FS
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 719e61d..ad94f26 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2430,6 +2430,75 @@ int btrfs_balance(struct btrfs_balance_control *bctl, int resume)
 		}
 	}
 
+	/*
+	 * Profile changing sanity checks.  Skip them if a simple
+	 * balance is requested.
+	 */
+	if (!((bctl->data.flags | bctl->sys.flags | bctl->meta.flags) &
+	      BTRFS_BALANCE_ARGS_CONVERT))
+		goto do_balance;
+
+	allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+	if (fs_info->fs_devices->num_devices == 1)
+		allowed |= BTRFS_BLOCK_GROUP_DUP;
+	else if (fs_info->fs_devices->num_devices < 4)
+		allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
+	else
+		allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
+				BTRFS_BLOCK_GROUP_RAID10);
+
+	if (!profile_is_valid(bctl->data.target, 1) ||
+	    bctl->data.target & ~allowed) {
+		printk(KERN_ERR "btrfs: unable to start balance with target "
+		       "data profile %llu\n",
+		       (unsigned long long)bctl->data.target);
+		ret = -EINVAL;
+		goto out;
+	}
+	if (!profile_is_valid(bctl->meta.target, 1) ||
+	    bctl->meta.target & ~allowed) {
+		printk(KERN_ERR "btrfs: unable to start balance with target "
+		       "metadata profile %llu\n",
+		       (unsigned long long)bctl->meta.target);
+		ret = -EINVAL;
+		goto out;
+	}
+	if (!profile_is_valid(bctl->sys.target, 1) ||
+	    bctl->sys.target & ~allowed) {
+		printk(KERN_ERR "btrfs: unable to start balance with target "
+		       "system profile %llu\n",
+		       (unsigned long long)bctl->sys.target);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (bctl->data.target & BTRFS_BLOCK_GROUP_DUP) {
+		printk(KERN_ERR "btrfs: dup for data is not allowed\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* allow to reduce meta or sys integrity only if force set */
+	allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
+			BTRFS_BLOCK_GROUP_RAID10;
+	if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+	     (fs_info->avail_system_alloc_bits & allowed) &&
+	     !(bctl->sys.target & allowed)) ||
+	    ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+	     (fs_info->avail_metadata_alloc_bits & allowed) &&
+	     !(bctl->meta.target & allowed))) {
+		if (bctl->flags & BTRFS_BALANCE_FORCE) {
+			printk(KERN_INFO "btrfs: force reducing metadata "
+			       "integrity\n");
+		} else {
+			printk(KERN_ERR "btrfs: balance will reduce metadata "
+			       "integrity, use force if you want this\n");
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+
+do_balance:
 	if (!resume)
 		set_balance_control(bctl);
 
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 879afcb..13ff08d 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -196,6 +196,9 @@ struct map_lookup {
 #define BTRFS_BALANCE_TYPE_MASK		(BTRFS_BALANCE_DATA |	    \
 					 BTRFS_BALANCE_SYSTEM |	    \
 					 BTRFS_BALANCE_METADATA)
+
+#define BTRFS_BALANCE_FORCE		(1ULL << 3)
+
 /*
  * Balance filters
  */
@@ -205,6 +208,8 @@ struct map_lookup {
 #define BTRFS_BALANCE_ARGS_DRANGE	(1ULL << 3)
 #define BTRFS_BALANCE_ARGS_VRANGE	(1ULL << 4)
 
+#define BTRFS_BALANCE_ARGS_CONVERT	(1ULL << 8)
+
 struct btrfs_balance_args;
 struct btrfs_balance_control {
 	struct btrfs_fs_info *fs_info;
-- 
1.7.6.3

[PATCH 14/21] Btrfs: soft profile changing mode (aka soft convert)

[Ilya Dryomov]

When doing convert from one profile to another if soft mode is on
restriper won't touch chunks that already have the profile we are
converting to.  This is useful if e.g. half of the FS was converted
earlier.

The soft mode switch is (like every other filter) per-type.  This means
that we can convert for example meta chunks the "hard" way while
converting data chunks selectively with soft switch.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/volumes.c |   22 ++++++++++++++++++++++
 fs/btrfs/volumes.h |    6 ++++++
 2 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index ad94f26..d1beac1 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2220,6 +2220,22 @@ static int chunk_vrange_filter(struct extent_buffer *leaf,
 	return 1;
 }
 
+static int chunk_soft_convert_filter(u64 chunk_profile,
+				     struct btrfs_balance_args *bargs)
+{
+	BUG_ON(!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT));
+
+	chunk_profile &= BTRFS_BLOCK_GROUP_PROFILE_MASK;
+
+	if (chunk_profile == 0)
+		chunk_profile = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+
+	if (bargs->target & chunk_profile)
+		return 1;
+
+	return 0;
+}
+
 static int should_balance_chunk(struct btrfs_root *root,
 				struct extent_buffer *leaf,
 				struct btrfs_chunk *chunk, u64 chunk_offset)
@@ -2271,6 +2287,12 @@ static int should_balance_chunk(struct btrfs_root *root,
 		return 0;
 	}
 
+	/* soft profile changing mode */
+	if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
+	    chunk_soft_convert_filter(chunk_type, bargs)) {
+		return 0;
+	}
+
 	return 1;
 }
 
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 13ff08d..9879a31 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -208,7 +208,13 @@ struct map_lookup {
 #define BTRFS_BALANCE_ARGS_DRANGE	(1ULL << 3)
 #define BTRFS_BALANCE_ARGS_VRANGE	(1ULL << 4)
 
+/*
+ * Profile changing flags.  When SOFT is set we won't relocate chunk if
+ * it already has the target profile (even though it may be
+ * half-filled).
+ */
 #define BTRFS_BALANCE_ARGS_CONVERT	(1ULL << 8)
+#define BTRFS_BALANCE_ARGS_SOFT		(1ULL << 9)
 
 struct btrfs_balance_args;
 struct btrfs_balance_control {
-- 
1.7.6.3

[PATCH 15/21] Btrfs: save balance parameters to disk

[Ilya Dryomov]

Introduce a new btree objectid for storing balance item.  The reason is
to be able to resume restriper after a crash with the same parameters.
Balance item has a very high objectid and goes into tree of tree roots.

The key for the new item is as follows:

	[ BTRFS_BALANCE_OBJECTID ; BTRFS_BALANCE_ITEM_KEY ; 0 ]

Older kernels simply ignore it so it's safe to mount with an older
kernel and then go back to the newer one.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ctree.h   |  133 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/volumes.c |  100 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 232 insertions(+), 1 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1e7aea6..9997a59 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -86,6 +86,9 @@ struct btrfs_ordered_sum;
 /* holds checksums of all the data extents */
 #define BTRFS_CSUM_TREE_OBJECTID 7ULL
 
+/* for storing balance parameters in the root tree */
+#define BTRFS_BALANCE_OBJECTID -4ULL
+
 /* orhpan objectid for tracking unlinked/truncated files */
 #define BTRFS_ORPHAN_OBJECTID -5ULL
 
@@ -692,6 +695,54 @@ struct btrfs_root_ref {
 	__le16 name_len;
 } __attribute__ ((__packed__));
 
+struct btrfs_disk_balance_args {
+	/*
+	 * profiles to operate on, single is denoted by
+	 * BTRFS_AVAIL_ALLOC_BIT_SINGLE
+	 */
+	__le64 profiles;
+
+	/* usage filter */
+	__le64 usage;
+
+	/* devid filter */
+	__le64 devid;
+
+	/* devid subset filter [pstart..pend) */
+	__le64 pstart;
+	__le64 pend;
+
+	/* btrfs virtual address space subset filter [vstart..vend) */
+	__le64 vstart;
+	__le64 vend;
+
+	/*
+	 * profile to convert to, single is denoted by
+	 * BTRFS_AVAIL_ALLOC_BIT_SINGLE
+	 */
+	__le64 target;
+
+	/* BTRFS_BALANCE_ARGS_* */
+	__le64 flags;
+
+	__le64 unused[8];
+} __attribute__ ((__packed__));
+
+/*
+ * store balance parameters to disk so that balance can be properly
+ * resumed after crash or unmount
+ */
+struct btrfs_balance_item {
+	/* BTRFS_BALANCE_* */
+	__le64 flags;
+
+	struct btrfs_disk_balance_args data;
+	struct btrfs_disk_balance_args meta;
+	struct btrfs_disk_balance_args sys;
+
+	__le64 unused[4];
+} __attribute__ ((__packed__));
+
 #define BTRFS_FILE_EXTENT_INLINE 0
 #define BTRFS_FILE_EXTENT_REG 1
 #define BTRFS_FILE_EXTENT_PREALLOC 2
@@ -1409,6 +1460,8 @@ struct btrfs_ioctl_defrag_range_args {
 #define BTRFS_DEV_ITEM_KEY	216
 #define BTRFS_CHUNK_ITEM_KEY	228
 
+#define BTRFS_BALANCE_ITEM_KEY	248
+
 /*
  * string items are for debugging.  They just store a short string of
  * data in the FS
@@ -2103,8 +2156,86 @@ BTRFS_SETGET_STACK_FUNCS(backup_bytes_used, struct btrfs_root_backup,
 BTRFS_SETGET_STACK_FUNCS(backup_num_devices, struct btrfs_root_backup,
 		   num_devices, 64);
 
-/* struct btrfs_super_block */
+/* struct btrfs_balance_item */
+BTRFS_SETGET_FUNCS(balance_flags, struct btrfs_balance_item, flags, 64);
+
+static inline void btrfs_balance_data(struct extent_buffer *eb,
+				      struct btrfs_balance_item *bi,
+				      struct btrfs_disk_balance_args *ba)
+{
+	read_eb_member(eb, bi, struct btrfs_balance_item, data, ba);
+}
+
+static inline void btrfs_set_balance_data(struct extent_buffer *eb,
+					  struct btrfs_balance_item *bi,
+					  struct btrfs_disk_balance_args *ba)
+{
+	write_eb_member(eb, bi, struct btrfs_balance_item, data, ba);
+}
+
+static inline void btrfs_balance_meta(struct extent_buffer *eb,
+				      struct btrfs_balance_item *bi,
+				      struct btrfs_disk_balance_args *ba)
+{
+	read_eb_member(eb, bi, struct btrfs_balance_item, meta, ba);
+}
+
+static inline void btrfs_set_balance_meta(struct extent_buffer *eb,
+					  struct btrfs_balance_item *bi,
+					  struct btrfs_disk_balance_args *ba)
+{
+	write_eb_member(eb, bi, struct btrfs_balance_item, meta, ba);
+}
+
+static inline void btrfs_balance_sys(struct extent_buffer *eb,
+				     struct btrfs_balance_item *bi,
+				     struct btrfs_disk_balance_args *ba)
+{
+	read_eb_member(eb, bi, struct btrfs_balance_item, sys, ba);
+}
+
+static inline void btrfs_set_balance_sys(struct extent_buffer *eb,
+					 struct btrfs_balance_item *bi,
+					 struct btrfs_disk_balance_args *ba)
+{
+	write_eb_member(eb, bi, struct btrfs_balance_item, sys, ba);
+}
 
+static inline void
+btrfs_disk_balance_args_to_cpu(struct btrfs_balance_args *cpu,
+			       struct btrfs_disk_balance_args *disk)
+{
+	memset(cpu, 0, sizeof(*cpu));
+
+	cpu->profiles = le64_to_cpu(disk->profiles);
+	cpu->usage = le64_to_cpu(disk->usage);
+	cpu->devid = le64_to_cpu(disk->devid);
+	cpu->pstart = le64_to_cpu(disk->pstart);
+	cpu->pend = le64_to_cpu(disk->pend);
+	cpu->vstart = le64_to_cpu(disk->vstart);
+	cpu->vend = le64_to_cpu(disk->vend);
+	cpu->target = le64_to_cpu(disk->target);
+	cpu->flags = le64_to_cpu(disk->flags);
+}
+
+static inline void
+btrfs_cpu_balance_args_to_disk(struct btrfs_disk_balance_args *disk,
+			       struct btrfs_balance_args *cpu)
+{
+	memset(disk, 0, sizeof(*disk));
+
+	disk->profiles = cpu_to_le64(cpu->profiles);
+	disk->usage = cpu_to_le64(cpu->usage);
+	disk->devid = cpu_to_le64(cpu->devid);
+	disk->pstart = cpu_to_le64(cpu->pstart);
+	disk->pend = cpu_to_le64(cpu->pend);
+	disk->vstart = cpu_to_le64(cpu->vstart);
+	disk->vend = cpu_to_le64(cpu->vend);
+	disk->target = cpu_to_le64(cpu->target);
+	disk->flags = cpu_to_le64(cpu->flags);
+}
+
+/* struct btrfs_super_block */
 BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);
 BTRFS_SETGET_STACK_FUNCS(super_flags, struct btrfs_super_block, flags, 64);
 BTRFS_SETGET_STACK_FUNCS(super_generation, struct btrfs_super_block,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d1beac1..1f9fdb7 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2073,6 +2073,97 @@ error:
 	return ret;
 }
 
+static int insert_balance_item(struct btrfs_root *root,
+			       struct btrfs_balance_control *bctl)
+{
+	struct btrfs_trans_handle *trans;
+	struct btrfs_balance_item *item;
+	struct btrfs_disk_balance_args disk_bargs;
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	int ret, err;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	trans = btrfs_start_transaction(root, 0);
+	if (IS_ERR(trans)) {
+		btrfs_free_path(path);
+		return PTR_ERR(trans);
+	}
+
+	key.objectid = BTRFS_BALANCE_OBJECTID;
+	key.type = BTRFS_BALANCE_ITEM_KEY;
+	key.offset = 0;
+
+	ret = btrfs_insert_empty_item(trans, root, path, &key,
+				      sizeof(*item));
+	if (ret)
+		goto out;
+
+	leaf = path->nodes[0];
+	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
+
+	memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
+
+	btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
+	btrfs_set_balance_data(leaf, item, &disk_bargs);
+	btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
+	btrfs_set_balance_meta(leaf, item, &disk_bargs);
+	btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
+	btrfs_set_balance_sys(leaf, item, &disk_bargs);
+
+	btrfs_set_balance_flags(leaf, item, bctl->flags);
+
+	btrfs_mark_buffer_dirty(leaf);
+out:
+	btrfs_free_path(path);
+	err = btrfs_commit_transaction(trans, root);
+	if (err && !ret)
+		ret = err;
+	return ret;
+}
+
+static int del_balance_item(struct btrfs_root *root)
+{
+	struct btrfs_trans_handle *trans;
+	struct btrfs_path *path;
+	struct btrfs_key key;
+	int ret, err;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	trans = btrfs_start_transaction(root, 0);
+	if (IS_ERR(trans)) {
+		btrfs_free_path(path);
+		return PTR_ERR(trans);
+	}
+
+	key.objectid = BTRFS_BALANCE_OBJECTID;
+	key.type = BTRFS_BALANCE_ITEM_KEY;
+	key.offset = 0;
+
+	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+	if (ret < 0)
+		goto out;
+	if (ret > 0) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	ret = btrfs_del_item(trans, root, path);
+out:
+	btrfs_free_path(path);
+	err = btrfs_commit_transaction(trans, root);
+	if (err && !ret)
+		ret = err;
+	return ret;
+}
+
 /*
  * Should be called with both balance and volume mutexes held to
  * serialize other volume operations (add_dev/rm_dev/resize) with
@@ -2419,7 +2510,11 @@ error:
 
 static void __cancel_balance(struct btrfs_fs_info *fs_info)
 {
+	int ret;
+
 	unset_balance_control(fs_info);
+	ret = del_balance_item(fs_info->tree_root);
+	BUG_ON(ret);
 }
 
 /*
@@ -2521,6 +2616,11 @@ int btrfs_balance(struct btrfs_balance_control *bctl, int resume)
 	}
 
 do_balance:
+	ret = insert_balance_item(fs_info->tree_root, bctl);
+	if (ret && ret != -EEXIST)
+		goto out;
+	BUG_ON((ret == -EEXIST && !resume) || (ret != -EEXIST && resume));
+
 	if (!resume)
 		set_balance_control(bctl);
 
-- 
1.7.6.3

[PATCH 16/21] Btrfs: recover balance on mount

[Ilya Dryomov]

On mount, if balance item is found, resume balance in a separate
kernel thread.

Try to be smart to continue roughly where previous balance (or convert)
was interrupted.  For chunk types that were being converted to some
profile we turn on soft convert, in case of a simple balance we turn on
usage filter and relocate only less-than-90%-full chunks of that type.
These are just heuristics but they help quite a bit, and can be improved
in future.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/disk-io.c |    4 ++
 fs/btrfs/volumes.c |  127 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/volumes.h |    1 +
 3 files changed, 131 insertions(+), 1 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 190a1b2..eb7a11a 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2427,6 +2427,10 @@ retry_root_backup:
 		if (!err)
 			err = btrfs_orphan_cleanup(fs_info->tree_root);
 		up_read(&fs_info->cleanup_work_sem);
+
+		if (!err)
+			err = btrfs_recover_balance(fs_info->tree_root);
+
 		if (err) {
 			close_ctree(tree_root);
 			return ERR_PTR(err);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1f9fdb7..c03df10 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -23,6 +23,7 @@
 #include <linux/random.h>
 #include <linux/iocontext.h>
 #include <linux/capability.h>
+#include <linux/kthread.h>
 #include <asm/div64.h>
 #include "compat.h"
 #include "ctree.h"
@@ -2165,6 +2166,46 @@ out:
 }
 
 /*
+ * This is a heuristic used to reduce the number of chunks balanced on
+ * resume after balance was interrupted.
+ */
+static void update_balance_args(struct btrfs_balance_control *bctl)
+{
+	/*
+	 * Turn on soft mode for chunk types that were being converted.
+	 */
+	if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
+		bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
+	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
+		bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
+	if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
+		bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
+
+	/*
+	 * Turn on usage filter if is not already used.  The idea is
+	 * that chunks that we have already balanced should be
+	 * reasonably full.  Don't do it for chunks that are being
+	 * converted - that will keep us from relocating unconverted
+	 * (albeit full) chunks.
+	 */
+	if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+	    !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
+		bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
+		bctl->data.usage = 90;
+	}
+	if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+	    !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
+		bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
+		bctl->sys.usage = 90;
+	}
+	if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+	    !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
+		bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
+		bctl->meta.usage = 90;
+	}
+}
+
+/*
  * Should be called with both balance and volume mutexes held to
  * serialize other volume operations (add_dev/rm_dev/resize) with
  * restriper.  Same goes for unset_balance_control.
@@ -2621,8 +2662,13 @@ do_balance:
 		goto out;
 	BUG_ON((ret == -EEXIST && !resume) || (ret != -EEXIST && resume));
 
-	if (!resume)
+	if (!resume) {
 		set_balance_control(bctl);
+	} else {
+		spin_lock(&fs_info->balance_lock);
+		update_balance_args(bctl);
+		spin_unlock(&fs_info->balance_lock);
+	}
 
 	mutex_unlock(&fs_info->balance_mutex);
 
@@ -2641,6 +2687,85 @@ out:
 	return ret;
 }
 
+static int restriper_kthread(void *data)
+{
+	struct btrfs_balance_control *bctl =
+			(struct btrfs_balance_control *)data;
+	struct btrfs_fs_info *fs_info = bctl->fs_info;
+	int ret;
+
+	mutex_lock(&fs_info->volume_mutex);
+	mutex_lock(&fs_info->balance_mutex);
+
+	set_balance_control(bctl);
+
+	printk(KERN_INFO "btrfs: continuing balance\n");
+	ret = btrfs_balance(bctl, 1);
+
+	mutex_unlock(&fs_info->balance_mutex);
+	mutex_unlock(&fs_info->volume_mutex);
+	return ret;
+}
+
+int btrfs_recover_balance(struct btrfs_root *tree_root)
+{
+	struct task_struct *tsk;
+	struct btrfs_balance_control *bctl;
+	struct btrfs_balance_item *item;
+	struct btrfs_disk_balance_args disk_bargs;
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	int ret;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
+	if (!bctl) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	key.objectid = BTRFS_BALANCE_OBJECTID;
+	key.type = BTRFS_BALANCE_ITEM_KEY;
+	key.offset = 0;
+
+	ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
+	if (ret < 0)
+		goto out_bctl;
+	if (ret > 0) { /* ret = -ENOENT; */
+		ret = 0;
+		goto out_bctl;
+	}
+
+	leaf = path->nodes[0];
+	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
+
+	bctl->fs_info = tree_root->fs_info;
+	bctl->flags = btrfs_balance_flags(leaf, item);
+
+	btrfs_balance_data(leaf, item, &disk_bargs);
+	btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
+	btrfs_balance_meta(leaf, item, &disk_bargs);
+	btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
+	btrfs_balance_sys(leaf, item, &disk_bargs);
+	btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
+
+	tsk = kthread_run(restriper_kthread, bctl, "btrfs-restriper");
+	if (IS_ERR(tsk))
+		ret = PTR_ERR(tsk);
+	else
+		goto out;
+
+out_bctl:
+	kfree(bctl);
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
 /*
  * shrinking a device means finding all of the device extents past
  * the new size, and then following the back refs to the chunks.
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 9879a31..bcaddd4 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -270,6 +270,7 @@ struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 int btrfs_init_new_device(struct btrfs_root *root, char *path);
 int btrfs_balance(struct btrfs_balance_control *rctl, int resume);
+int btrfs_recover_balance(struct btrfs_root *tree_root);
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 			 struct btrfs_device *device, u64 num_bytes,
-- 
1.7.6.3

[PATCH 17/21] Btrfs: add skip_balance mount option

[Ilya Dryomov]

Since restriper kthread starts involuntarily on mount and can suck cpu
and memory bandwidth add a mount option to forcefully skip it.  The
restriper in that case hangs around in paused state and can be resumed
from userspace when it's convenient.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ctree.h   |    1 +
 fs/btrfs/super.c   |   11 +++++++++--
 fs/btrfs/volumes.c |   10 +++++++---
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 9997a59..99eb2bc 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1492,6 +1492,7 @@ struct btrfs_ioctl_defrag_range_args {
 #define BTRFS_MOUNT_AUTO_DEFRAG		(1 << 16)
 #define BTRFS_MOUNT_INODE_MAP_CACHE	(1 << 17)
 #define BTRFS_MOUNT_RECOVERY		(1 << 18)
+#define BTRFS_MOUNT_SKIP_BALANCE	(1 << 19)
 
 #define btrfs_clear_opt(o, opt)		((o) &= ~BTRFS_MOUNT_##opt)
 #define btrfs_set_opt(o, opt)		((o) |= BTRFS_MOUNT_##opt)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 34a8b61..063b521 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -164,8 +164,9 @@ enum {
 	Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
 	Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
 	Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
-	Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
-	Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_err,
+	Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
+	Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
+	Opt_err,
 };
 
 static match_table_t tokens = {
@@ -200,6 +201,7 @@ static match_table_t tokens = {
 	{Opt_inode_cache, "inode_cache"},
 	{Opt_no_space_cache, "nospace_cache"},
 	{Opt_recovery, "recovery"},
+	{Opt_skip_balance, "skip_balance"},
 	{Opt_err, NULL},
 };
 
@@ -398,6 +400,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
 			printk(KERN_INFO "btrfs: enabling auto recovery");
 			btrfs_set_opt(info->mount_opt, RECOVERY);
 			break;
+		case Opt_skip_balance:
+			btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
+			break;
 		case Opt_err:
 			printk(KERN_INFO "btrfs: unrecognized mount option "
 			       "'%s'\n", p);
@@ -723,6 +728,8 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 		seq_puts(seq, ",autodefrag");
 	if (btrfs_test_opt(root, INODE_MAP_CACHE))
 		seq_puts(seq, ",inode_cache");
+	if (btrfs_test_opt(root, SKIP_BALANCE))
+		seq_puts(seq, ",skip_balance");
 	return 0;
 }
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c03df10..c50a0af 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2692,15 +2692,19 @@ static int restriper_kthread(void *data)
 	struct btrfs_balance_control *bctl =
 			(struct btrfs_balance_control *)data;
 	struct btrfs_fs_info *fs_info = bctl->fs_info;
-	int ret;
+	int ret = 0;
 
 	mutex_lock(&fs_info->volume_mutex);
 	mutex_lock(&fs_info->balance_mutex);
 
 	set_balance_control(bctl);
 
-	printk(KERN_INFO "btrfs: continuing balance\n");
-	ret = btrfs_balance(bctl, 1);
+	if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
+		printk(KERN_INFO "btrfs: force skipping balance\n");
+	} else {
+		printk(KERN_INFO "btrfs: continuing balance\n");
+		ret = btrfs_balance(bctl, 1);
+	}
 
 	mutex_unlock(&fs_info->balance_mutex);
 	mutex_unlock(&fs_info->volume_mutex);
-- 
1.7.6.3

[PATCH 18/21] Btrfs: allow for pausing restriper

[Ilya Dryomov]

Implement an ioctl for pausing restriper.  This pauses the relocation,
but balance is still considered to be "in progress": balance item is
not deleted, other volume operations cannot be started, etc.  If paused
in the middle of profile changing operation we will continue making
allocations with the target profile.

Add a hook to close_ctree() to pause restriper and free it's data
structures on unmount.  (It's safe to unmount when restriper is in
"paused" state, we will resume with the same parameters on the next
mount)

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ctree.h   |    4 ++++
 fs/btrfs/disk-io.c |    6 ++++++
 fs/btrfs/ioctl.c   |   23 ++++++++++++++++++++++-
 fs/btrfs/ioctl.h   |    4 ++++
 fs/btrfs/volumes.c |   52 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 fs/btrfs/volumes.h |    1 +
 6 files changed, 87 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 99eb2bc..1afda75 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1214,7 +1214,10 @@ struct btrfs_fs_info {
 	/* restriper state */
 	spinlock_t balance_lock;
 	struct mutex balance_mutex;
+	atomic_t balance_running;
+	atomic_t balance_pause_req;
 	struct btrfs_balance_control *balance_ctl;
+	wait_queue_head_t balance_wait_q;
 
 	unsigned data_chunk_allocations;
 	unsigned metadata_ratio;
@@ -2658,6 +2661,7 @@ static inline int btrfs_fs_closing(struct btrfs_fs_info *fs_info)
 }
 static inline void free_fs_info(struct btrfs_fs_info *fs_info)
 {
+	kfree(fs_info->balance_ctl);
 	kfree(fs_info->delayed_root);
 	kfree(fs_info->extent_root);
 	kfree(fs_info->tree_root);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index eb7a11a..8ce8374 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2004,7 +2004,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	spin_lock_init(&fs_info->balance_lock);
 	mutex_init(&fs_info->balance_mutex);
+	atomic_set(&fs_info->balance_running, 0);
+	atomic_set(&fs_info->balance_pause_req, 0);
 	fs_info->balance_ctl = NULL;
+	init_waitqueue_head(&fs_info->balance_wait_q);
 
 	sb->s_blocksize = 4096;
 	sb->s_blocksize_bits = blksize_bits(4096);
@@ -2980,6 +2983,9 @@ int close_ctree(struct btrfs_root *root)
 	fs_info->closing = 1;
 	smp_mb();
 
+	/* pause restriper - we want to resume on mount */
+	btrfs_pause_balance(root->fs_info);
+
 	btrfs_scrub_cancel(root);
 
 	/* wait for any defraggers to finish */
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index e20d0cb..7830fae 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3081,6 +3081,11 @@ static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
 	mutex_lock(&fs_info->volume_mutex);
 	mutex_lock(&fs_info->balance_mutex);
 
+	if (fs_info->balance_ctl) {
+		ret = -EINPROGRESS;
+		goto out;
+	}
+
 	bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
 	if (!bctl) {
 		ret = -ENOMEM;
@@ -3108,7 +3113,8 @@ static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
 
 	ret = btrfs_balance(bctl, 0);
 	/*
-	 * bctl is freed in __cancel_balance
+	 * bctl is freed in __cancel_balance or in free_fs_info if
+	 * restriper was paused all the way until unmount
 	 */
 	kfree(bargs);
 out:
@@ -3117,6 +3123,19 @@ out:
 	return ret;
 }
 
+static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
+{
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case BTRFS_BALANCE_CTL_PAUSE:
+		return btrfs_pause_balance(root->fs_info);
+	}
+
+	return -EINVAL;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
 		cmd, unsigned long arg)
 {
@@ -3195,6 +3214,8 @@ long btrfs_ioctl(struct file *file, unsigned int
 		return btrfs_ioctl_scrub_progress(root, argp);
 	case BTRFS_IOC_BALANCE_V2:
 		return btrfs_ioctl_balance(root, argp);
+	case BTRFS_IOC_BALANCE_CTL:
+		return btrfs_ioctl_balance_ctl(root, arg);
 	}
 
 	return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 0ca8059..f069138 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -109,6 +109,9 @@ struct btrfs_ioctl_fs_info_args {
 	__u64 reserved[124];			/* pad to 1k */
 };
 
+/* balance control ioctl modes */
+#define BTRFS_BALANCE_CTL_PAUSE		1
+
 /*
  * this is packed, because it should be exactly the same as its disk
  * byte order counterpart (struct btrfs_disk_balance_args)
@@ -315,6 +318,7 @@ struct btrfs_ioctl_logical_ino_args {
 			       struct btrfs_ioctl_fs_info_args)
 #define BTRFS_IOC_BALANCE_V2 _IOW(BTRFS_IOCTL_MAGIC, 32, \
 				  struct btrfs_ioctl_balance_args)
+#define BTRFS_IOC_BALANCE_CTL _IOW(BTRFS_IOCTL_MAGIC, 33, int)
 #define BTRFS_IOC_INO_PATHS _IOWR(BTRFS_IOCTL_MAGIC, 35, \
 					struct btrfs_ioctl_ino_path_args)
 #define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c50a0af..9d15819 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2490,6 +2490,11 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 	key.type = BTRFS_CHUNK_ITEM_KEY;
 
 	while (1) {
+		if (atomic_read(&fs_info->balance_pause_req)) {
+			ret = -ECANCELED;
+			goto error;
+		}
+
 		ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
 		if (ret < 0)
 			goto error;
@@ -2549,6 +2554,11 @@ error:
 	return ret;
 }
 
+static inline int balance_need_close(struct btrfs_fs_info *fs_info)
+{
+	return atomic_read(&fs_info->balance_pause_req) == 0;
+}
+
 static void __cancel_balance(struct btrfs_fs_info *fs_info)
 {
 	int ret;
@@ -2567,9 +2577,11 @@ int btrfs_balance(struct btrfs_balance_control *bctl, int resume)
 	u64 allowed;
 	int ret;
 
-	if (btrfs_fs_closing(fs_info)) {
+	if (btrfs_fs_closing(fs_info) ||
+	    atomic_read(&fs_info->balance_pause_req)) {
 		ret = -EINVAL;
 		goto out;
+	}
 
 	/*
 	 * In case of mixed groups both data and meta should be picked,
@@ -2670,13 +2682,20 @@ do_balance:
 		spin_unlock(&fs_info->balance_lock);
 	}
 
+	atomic_inc(&fs_info->balance_running);
 	mutex_unlock(&fs_info->balance_mutex);
 
 	ret = __btrfs_balance(fs_info);
 
 	mutex_lock(&fs_info->balance_mutex);
+	atomic_dec(&fs_info->balance_running);
 
-	__cancel_balance(fs_info);
+	if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
+	    balance_need_close(fs_info)) {
+		__cancel_balance(fs_info);
+	}
+
+	wake_up(&fs_info->balance_wait_q);
 
 	return ret;
 out:
@@ -2770,6 +2789,35 @@ out:
 	return ret;
 }
 
+int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
+{
+	int ret = 0;
+
+	mutex_lock(&fs_info->balance_mutex);
+	if (!fs_info->balance_ctl) {
+		mutex_unlock(&fs_info->balance_mutex);
+		return -ENOTCONN;
+	}
+
+	if (atomic_read(&fs_info->balance_running)) {
+		atomic_inc(&fs_info->balance_pause_req);
+		mutex_unlock(&fs_info->balance_mutex);
+
+		wait_event(fs_info->balance_wait_q,
+			   atomic_read(&fs_info->balance_running) == 0);
+
+		mutex_lock(&fs_info->balance_mutex);
+		/* we are good with balance_ctl ripped off from under us */
+		BUG_ON(atomic_read(&fs_info->balance_running));
+		atomic_dec(&fs_info->balance_pause_req);
+	} else {
+		ret = -ENOTCONN;
+	}
+
+	mutex_unlock(&fs_info->balance_mutex);
+	return ret;
+}
+
 /*
  * shrinking a device means finding all of the device extents past
  * the new size, and then following the back refs to the chunks.
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index bcaddd4..2f74695 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -271,6 +271,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 int btrfs_init_new_device(struct btrfs_root *root, char *path);
 int btrfs_balance(struct btrfs_balance_control *rctl, int resume);
 int btrfs_recover_balance(struct btrfs_root *tree_root);
+int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 			 struct btrfs_device *device, u64 num_bytes,
-- 
1.7.6.3

[PATCH 19/21] Btrfs: allow for cancelling restriper

[Ilya Dryomov]

Implement an ioctl for cancelling restriper.  Currently we wait until
relocation of the current block group is finished, in future this can be
done by triggering a commit.  Balance item is deleted and no memory
about the interrupted balance is kept.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ctree.h   |    1 +
 fs/btrfs/disk-io.c |    1 +
 fs/btrfs/ioctl.c   |    2 ++
 fs/btrfs/ioctl.h   |    1 +
 fs/btrfs/volumes.c |   47 ++++++++++++++++++++++++++++++++++++++++++++---
 fs/btrfs/volumes.h |    1 +
 6 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1afda75..dfc136c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1216,6 +1216,7 @@ struct btrfs_fs_info {
 	struct mutex balance_mutex;
 	atomic_t balance_running;
 	atomic_t balance_pause_req;
+	atomic_t balance_cancel_req;
 	struct btrfs_balance_control *balance_ctl;
 	wait_queue_head_t balance_wait_q;
 
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8ce8374..c23b82d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2006,6 +2006,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	mutex_init(&fs_info->balance_mutex);
 	atomic_set(&fs_info->balance_running, 0);
 	atomic_set(&fs_info->balance_pause_req, 0);
+	atomic_set(&fs_info->balance_cancel_req, 0);
 	fs_info->balance_ctl = NULL;
 	init_waitqueue_head(&fs_info->balance_wait_q);
 
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7830fae..d47ff8e 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3131,6 +3131,8 @@ static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
 	switch (cmd) {
 	case BTRFS_BALANCE_CTL_PAUSE:
 		return btrfs_pause_balance(root->fs_info);
+	case BTRFS_BALANCE_CTL_CANCEL:
+		return btrfs_cancel_balance(root->fs_info);
 	}
 
 	return -EINVAL;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index f069138..33ec6d8 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -111,6 +111,7 @@ struct btrfs_ioctl_fs_info_args {
 
 /* balance control ioctl modes */
 #define BTRFS_BALANCE_CTL_PAUSE		1
+#define BTRFS_BALANCE_CTL_CANCEL	2
 
 /*
  * this is packed, because it should be exactly the same as its disk
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9d15819..f7248c9 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2490,7 +2490,8 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 	key.type = BTRFS_CHUNK_ITEM_KEY;
 
 	while (1) {
-		if (atomic_read(&fs_info->balance_pause_req)) {
+		if (atomic_read(&fs_info->balance_pause_req) ||
+		    atomic_read(&fs_info->balance_cancel_req)) {
 			ret = -ECANCELED;
 			goto error;
 		}
@@ -2556,7 +2557,10 @@ error:
 
 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
 {
-	return atomic_read(&fs_info->balance_pause_req) == 0;
+	/* cancel requested || normal exit path */
+	return atomic_read(&fs_info->balance_cancel_req) ||
+		(atomic_read(&fs_info->balance_pause_req) == 0 &&
+		 atomic_read(&fs_info->balance_cancel_req) == 0);
 }
 
 static void __cancel_balance(struct btrfs_fs_info *fs_info)
@@ -2578,7 +2582,8 @@ int btrfs_balance(struct btrfs_balance_control *bctl, int resume)
 	int ret;
 
 	if (btrfs_fs_closing(fs_info) ||
-	    atomic_read(&fs_info->balance_pause_req)) {
+	    atomic_read(&fs_info->balance_pause_req) ||
+	    atomic_read(&fs_info->balance_cancel_req)) {
 		ret = -EINVAL;
 		goto out;
 	}
@@ -2818,6 +2823,42 @@ int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
 	return ret;
 }
 
+int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
+{
+	mutex_lock(&fs_info->balance_mutex);
+	if (!fs_info->balance_ctl) {
+		mutex_unlock(&fs_info->balance_mutex);
+		return -ENOTCONN;
+	}
+
+	atomic_inc(&fs_info->balance_cancel_req);
+	/*
+	 * if we are running just wait and return, balance item is
+	 * deleted in btrfs_balance in this case
+	 */
+	if (atomic_read(&fs_info->balance_running)) {
+		mutex_unlock(&fs_info->balance_mutex);
+		wait_event(fs_info->balance_wait_q,
+			   atomic_read(&fs_info->balance_running) == 0);
+		mutex_lock(&fs_info->balance_mutex);
+	} else {
+		/* __cancel_balance needs volume_mutex */
+		mutex_unlock(&fs_info->balance_mutex);
+		mutex_lock(&fs_info->volume_mutex);
+		mutex_lock(&fs_info->balance_mutex);
+
+		if (fs_info->balance_ctl)
+			__cancel_balance(fs_info);
+
+		mutex_unlock(&fs_info->volume_mutex);
+	}
+
+	BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
+	atomic_dec(&fs_info->balance_cancel_req);
+	mutex_unlock(&fs_info->balance_mutex);
+	return 0;
+}
+
 /*
  * shrinking a device means finding all of the device extents past
  * the new size, and then following the back refs to the chunks.
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 2f74695..4429efc 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -272,6 +272,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *path);
 int btrfs_balance(struct btrfs_balance_control *rctl, int resume);
 int btrfs_recover_balance(struct btrfs_root *tree_root);
 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
+int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 			 struct btrfs_device *device, u64 num_bytes,
-- 
1.7.6.3

[PATCH 20/21] Btrfs: allow for resuming restriper after it was paused

[Ilya Dryomov]

Implement an ioctl for resuming restriper.  We use the same heuristics
used when recovering balance after a crash to try to start where we left
off last time.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ioctl.c   |    2 ++
 fs/btrfs/ioctl.h   |    1 +
 fs/btrfs/volumes.c |   27 +++++++++++++++++++++++++++
 fs/btrfs/volumes.h |    1 +
 4 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index d47ff8e..a83b1a5 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3133,6 +3133,8 @@ static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
 		return btrfs_pause_balance(root->fs_info);
 	case BTRFS_BALANCE_CTL_CANCEL:
 		return btrfs_cancel_balance(root->fs_info);
+	case BTRFS_BALANCE_CTL_RESUME:
+		return btrfs_resume_balance(root->fs_info);
 	}
 
 	return -EINVAL;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 33ec6d8..c691ef4 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -112,6 +112,7 @@ struct btrfs_ioctl_fs_info_args {
 /* balance control ioctl modes */
 #define BTRFS_BALANCE_CTL_PAUSE		1
 #define BTRFS_BALANCE_CTL_CANCEL	2
+#define BTRFS_BALANCE_CTL_RESUME	3
 
 /*
  * this is packed, because it should be exactly the same as its disk
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f7248c9..d907635 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2859,6 +2859,33 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
 	return 0;
 }
 
+int btrfs_resume_balance(struct btrfs_fs_info *fs_info)
+{
+	int ret;
+
+	if (fs_info->sb->s_flags & MS_RDONLY)
+		return -EROFS;
+
+	mutex_lock(&fs_info->volume_mutex);
+	mutex_lock(&fs_info->balance_mutex);
+
+	if (!fs_info->balance_ctl) {
+		ret = -ENOTCONN;
+		goto out;
+	}
+
+	if (atomic_read(&fs_info->balance_running)) {
+		ret = -EINPROGRESS;
+		goto out;
+	}
+
+	ret = btrfs_balance(fs_info->balance_ctl, 1);
+out:
+	mutex_unlock(&fs_info->balance_mutex);
+	mutex_unlock(&fs_info->volume_mutex);
+	return ret;
+}
+
 /*
  * shrinking a device means finding all of the device extents past
  * the new size, and then following the back refs to the chunks.
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 4429efc..6271d8e 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -273,6 +273,7 @@ int btrfs_balance(struct btrfs_balance_control *rctl, int resume);
 int btrfs_recover_balance(struct btrfs_root *tree_root);
 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
+int btrfs_resume_balance(struct btrfs_fs_info *fs_info);
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 			 struct btrfs_device *device, u64 num_bytes,
-- 
1.7.6.3

[PATCH 21/21] Btrfs: add balance progress reporting

[Ilya Dryomov]

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 fs/btrfs/ioctl.c   |   51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/ioctl.h   |    6 ++++++
 fs/btrfs/volumes.c |   35 +++++++++++++++++++++++++++++++++--
 fs/btrfs/volumes.h |    3 +++
 4 files changed, 93 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index a83b1a5..47abfc2 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3140,6 +3140,55 @@ static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
 	return -EINVAL;
 }
 
+static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
+					 void __user *arg)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_ioctl_balance_args *bargs;
+	struct btrfs_balance_control *bctl;
+	int ret = 0;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	mutex_lock(&fs_info->balance_mutex);
+	if (!(bctl = fs_info->balance_ctl)) {
+		ret = -ENOTCONN;
+		goto out;
+	}
+
+	bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
+	if (!bargs) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	bargs->flags = bctl->flags;
+
+	if (atomic_read(&fs_info->balance_running))
+		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
+	if (atomic_read(&fs_info->balance_cancel_req))
+		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
+	if (atomic_read(&fs_info->balance_pause_req))
+		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
+
+	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
+	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
+	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
+
+	spin_lock(&fs_info->balance_lock);
+	memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
+	spin_unlock(&fs_info->balance_lock);
+
+	if (copy_to_user(arg, bargs, sizeof(*bargs)))
+		ret = -EFAULT;
+
+	kfree(bargs);
+out:
+	mutex_unlock(&fs_info->balance_mutex);
+	return ret;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
 		cmd, unsigned long arg)
 {
@@ -3220,6 +3269,8 @@ long btrfs_ioctl(struct file *file, unsigned int
 		return btrfs_ioctl_balance(root, argp);
 	case BTRFS_IOC_BALANCE_CTL:
 		return btrfs_ioctl_balance_ctl(root, arg);
+	case BTRFS_IOC_BALANCE_PROGRESS:
+		return btrfs_ioctl_balance_progress(root, argp);
 	}
 
 	return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index c691ef4..04f8c1b 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -142,6 +142,10 @@ struct btrfs_balance_progress {
 	__u64 completed;	/* # of chunks relocated so far */
 };
 
+#define BTRFS_BALANCE_STATE_RUNNING	(1ULL << 0)
+#define BTRFS_BALANCE_STATE_CANCEL_REQ	(1ULL << 1)
+#define BTRFS_BALANCE_STATE_PAUSE_REQ	(1ULL << 2)
+
 struct btrfs_ioctl_balance_args {
 	__u64 flags;				/* in/out */
 	__u64 state;				/* out */
@@ -321,6 +325,8 @@ struct btrfs_ioctl_logical_ino_args {
 #define BTRFS_IOC_BALANCE_V2 _IOW(BTRFS_IOCTL_MAGIC, 32, \
 				  struct btrfs_ioctl_balance_args)
 #define BTRFS_IOC_BALANCE_CTL _IOW(BTRFS_IOCTL_MAGIC, 33, int)
+#define BTRFS_IOC_BALANCE_PROGRESS _IOR(BTRFS_IOCTL_MAGIC, 34, \
+					struct btrfs_ioctl_balance_args)
 #define BTRFS_IOC_INO_PATHS _IOWR(BTRFS_IOCTL_MAGIC, 35, \
 					struct btrfs_ioctl_ino_path_args)
 #define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d907635..d7c5c7d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2439,6 +2439,7 @@ static u64 div_factor(u64 num, int factor)
 
 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 {
+	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
 	struct btrfs_root *chunk_root = fs_info->chunk_root;
 	struct btrfs_root *dev_root = fs_info->dev_root;
 	struct list_head *devices;
@@ -2454,6 +2455,7 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 	int slot;
 	int ret;
 	int enospc_errors = 0;
+	bool counting = true;
 
 	/* step one make some room on all the devices */
 	devices = &fs_info->fs_devices->devices;
@@ -2485,12 +2487,18 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 		ret = -ENOMEM;
 		goto error;
 	}
+
+	/* zero out stat counters */
+	spin_lock(&fs_info->balance_lock);
+	memset(&bctl->stat, 0, sizeof(bctl->stat));
+	spin_unlock(&fs_info->balance_lock);
+again:
 	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
 	key.offset = (u64)-1;
 	key.type = BTRFS_CHUNK_ITEM_KEY;
 
 	while (1) {
-		if (atomic_read(&fs_info->balance_pause_req) ||
+		if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
 		    atomic_read(&fs_info->balance_cancel_req)) {
 			ret = -ECANCELED;
 			goto error;
@@ -2525,24 +2533,47 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 
 		chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
 
+		if (!counting) {
+			spin_lock(&fs_info->balance_lock);
+			bctl->stat.considered++;
+			spin_unlock(&fs_info->balance_lock);
+		}
+
 		ret = should_balance_chunk(chunk_root, leaf, chunk,
 					   found_key.offset);
 		btrfs_release_path(path);
 		if (!ret)
 			goto loop;
 
+		if (counting) {
+			spin_lock(&fs_info->balance_lock);
+			bctl->stat.expected++;
+			spin_unlock(&fs_info->balance_lock);
+			goto loop;
+		}
+
 		ret = btrfs_relocate_chunk(chunk_root,
 					   chunk_root->root_key.objectid,
 					   found_key.objectid,
 					   found_key.offset);
 		if (ret && ret != -ENOSPC)
 			goto error;
-		if (ret == -ENOSPC)
+		if (ret == -ENOSPC) {
 			enospc_errors++;
+		} else {
+			spin_lock(&fs_info->balance_lock);
+			bctl->stat.completed++;
+			spin_unlock(&fs_info->balance_lock);
+		}
 loop:
 		key.offset = found_key.offset - 1;
 	}
 
+	if (counting) {
+		btrfs_release_path(path);
+		counting = false;
+		goto again;
+	}
 error:
 	btrfs_free_path(path);
 	if (enospc_errors) {
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 6271d8e..ae1d9bd 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -217,6 +217,7 @@ struct map_lookup {
 #define BTRFS_BALANCE_ARGS_SOFT		(1ULL << 9)
 
 struct btrfs_balance_args;
+struct btrfs_balance_progress;
 struct btrfs_balance_control {
 	struct btrfs_fs_info *fs_info;
 
@@ -225,6 +226,8 @@ struct btrfs_balance_control {
 	struct btrfs_balance_args sys;
 
 	u64 flags;
+
+	struct btrfs_balance_progress stat;
 };
 
 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
-- 
1.7.6.3

Re: [PATCH 00/21] Btrfs: restriper

[Marios Titas]

I tried this for many different scenarios and it seems to work pretty
well. I only ran into one problematic case: If you remove a device
from a multidevice filesystem it crashes. Here's how to reproduce it:

truncate -s1g /tmp/test1
truncate -s1g /tmp/test2
losetup /dev/loop1 /tmp/test1
losetup /dev/loop2 /tmp/test2
mkdir /tmp/test
./mkfs.btrfs -L test -d single -m single /dev/loop1 /dev/loop2
mount -o noatime /dev/loop1 /tmp/test
./btrfs dev del /dev/loop1 /tmp/test
./btrfs fi bal start /tmp/test

There is no actual restriping involved but the above example does work
corretly under 3.1+for-linus whereas it fails with your patches.

Re: [PATCH 00/21] Btrfs: restriper

[Ilya Dryomov]

On Mon, Jan 09, 2012 at 01:50:34AM -0500, Marios Titas wrote:
> I tried this for many different scenarios and it seems to work pretty
> well. I only ran into one problematic case: If you remove a device
> from a multidevice filesystem it crashes. Here's how to reproduce it:
> 
> truncate -s1g /tmp/test1
> truncate -s1g /tmp/test2
> losetup /dev/loop1 /tmp/test1
> losetup /dev/loop2 /tmp/test2
> mkdir /tmp/test
> ./mkfs.btrfs -L test -d single -m single /dev/loop1 /dev/loop2
> mount -o noatime /dev/loop1 /tmp/test
> ./btrfs dev del /dev/loop1 /tmp/test
> ./btrfs fi bal start /tmp/test
> 
> There is no actual restriping involved but the above example does work
> corretly under 3.1+for-linus whereas it fails with your patches.

Thanks for your testing.  The good news is that I put that BUG() there
simply for debugging so it's nothing major:

2520                    if (ret)
2521                            BUG(); /* FIXME break ? */

It used to be just a break out of the loop there, so that's the reason
it doesn't panic with 3.1+for-linus.  I'll investigate further and fix
this.

Thanks,

		Ilya

Re: [PATCH 00/21] Btrfs: restriper

[Ilya Dryomov]

On Mon, Jan 09, 2012 at 03:44:18PM +0200, Ilya Dryomov wrote:
> On Mon, Jan 09, 2012 at 01:50:34AM -0500, Marios Titas wrote:
> > I tried this for many different scenarios and it seems to work pretty
> > well. I only ran into one problematic case: If you remove a device
> > from a multidevice filesystem it crashes. Here's how to reproduce it:
> > 
> > truncate -s1g /tmp/test1
> > truncate -s1g /tmp/test2
> > losetup /dev/loop1 /tmp/test1
> > losetup /dev/loop2 /tmp/test2
> > mkdir /tmp/test
> > ./mkfs.btrfs -L test -d single -m single /dev/loop1 /dev/loop2
> > mount -o noatime /dev/loop1 /tmp/test
> > ./btrfs dev del /dev/loop1 /tmp/test
> > ./btrfs fi bal start /tmp/test
> > 
> > There is no actual restriping involved but the above example does work
> > corretly under 3.1+for-linus whereas it fails with your patches.
> 
> Thanks for your testing.  The good news is that I put that BUG() there
> simply for debugging so it's nothing major:
> 
> 2520                    if (ret)
> 2521                            BUG(); /* FIXME break ? */
> 
> It used to be just a break out of the loop there, so that's the reason
> it doesn't panic with 3.1+for-linus.  I'll investigate further and fix
> this.

I force-rebased my tree, removed two other BUG_ONs along with this one.

Thanks,

		Ilya



diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d7c5c7d..9b3d03d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2312,7 +2312,8 @@ static int chunk_drange_filter(struct extent_buffer *leaf,
 	int factor;
 	int i;
 
-	BUG_ON(!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID));
+	if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
+		return 0;
 
 	if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
 	     BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
@@ -2355,7 +2356,8 @@ static int chunk_vrange_filter(struct extent_buffer *leaf,
 static int chunk_soft_convert_filter(u64 chunk_profile,
 				     struct btrfs_balance_args *bargs)
 {
-	BUG_ON(!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT));
+	if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
+		return 0;
 
 	chunk_profile &= BTRFS_BLOCK_GROUP_PROFILE_MASK;
 
@@ -2518,7 +2520,7 @@ again:
 		ret = btrfs_previous_item(chunk_root, path, 0,
 					  BTRFS_CHUNK_ITEM_KEY);
 		if (ret)
-			BUG(); /* FIXME break ? */
+			break;
 
 		leaf = path->nodes[0];
 		slot = path->slots[0];

Re: [PATCH 16/21] Btrfs: recover balance on mount

[David Sterba]

On Fri, Jan 06, 2012 at 04:31:04PM +0200, Ilya Dryomov wrote:
> +static int restriper_kthread(void *data)

you've changed restripe -> balance in some places, I'm not sure if you
want to distinguish them sometimes, like the kthread worker name here

> +{
...
> +}
> +
> +int btrfs_recover_balance(struct btrfs_root *tree_root)
> +{
...
> +	btrfs_balance_data(leaf, item, &disk_bargs);
> +	btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
> +	btrfs_balance_meta(leaf, item, &disk_bargs);
> +	btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
> +	btrfs_balance_sys(leaf, item, &disk_bargs);
> +	btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
> +
> +	tsk = kthread_run(restriper_kthread, bctl, "btrfs-restriper");

or process name here.

Nothing serious, I noticed this while diffing the previous version.


david

Re: [PATCH 16/21] Btrfs: recover balance on mount

[Ilya Dryomov]

On Thu, Jan 12, 2012 at 03:00:31PM +0100, David Sterba wrote:
> On Fri, Jan 06, 2012 at 04:31:04PM +0200, Ilya Dryomov wrote:
> > +static int restriper_kthread(void *data)
> 
> you've changed restripe -> balance in some places, I'm not sure if you
> want to distinguish them sometimes, like the kthread worker name here
> 
> > +{
> ...
> > +}
> > +
> > +int btrfs_recover_balance(struct btrfs_root *tree_root)
> > +{
> ...
> > +	btrfs_balance_data(leaf, item, &disk_bargs);
> > +	btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
> > +	btrfs_balance_meta(leaf, item, &disk_bargs);
> > +	btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
> > +	btrfs_balance_sys(leaf, item, &disk_bargs);
> > +	btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
> > +
> > +	tsk = kthread_run(restriper_kthread, bctl, "btrfs-restriper");
> 
> or process name here.
> 
> Nothing serious, I noticed this while diffing the previous version.

I'll change it to btrfs-balance and balance_kthread.  Thanks for
reviewing!

		Ilya

Re: [PATCH 00/21] Btrfs: restriper

[Jérôme Poulin]

On Fri, Jan 6, 2012 at 9:30 AM, Ilya Dryomov <idryomov@gmail.com> wrote=
:
> This is a respin of restriper patch series which adds an initial
> implementation of restriper (it's a clever name for relocation framew=
ork
> that allows to do selective profile changing and selective balancing
> with some goodies like pausing/resuming and reporting progress to the
> user). =C2=A0See userspace cover patch for usage examples.

I just tried merging this on my kernel 3.2.1 and it seems to work
nicely. I compiled your btrfs-progs, made an LVM snapshot and launched
a balance on my 300 GB filesystem converted from ext4. It worked for
converting my metadata from single to dup, however, it didn't succeed
converting my system from single to dup.

Here is the command I used:
root /usr/src/kernel/btrfs-progs # ./btrfs balance start -f -v
-sconvert=3Ddup -mconvert=3Ddup /mnt/btrfs/
Dumping filters: flags 0xe, state 0x0, force is on
  METADATA (flags 0x100): converting, target=3D32, soft is off
  SYSTEM (flags 0x100): converting, target=3D32, soft is off
Done, had to relocate 28 out of 220 chunks

Then tried:
root /usr/src/kernel/btrfs-progs # ./btrfs balance start -f -v
-sconvert=3Ddup /mnt/btrfs/
Dumping filters: flags 0xa, state 0x0, force is on
  SYSTEM (flags 0x100): converting, target=3D32, soft is off
Done, had to relocate 0 out of 239 chunks

Before:
root /usr/src/kernel/btrfs-progs # ./btrfs fi df /mnt/btrfs/
Data: total=3D217.33GB, used=3D211.68GB
System: total=3D32.00MB, used=3D28.00KB
Metadata: total=3D19.39GB, used=3D14.18GB

And here is the result after balance:
root /usr/src/kernel/btrfs-progs # ./btrfs fi df /mnt/btrfs/
Data: total=3D226.33GB, used=3D225.56GB
System: total=3D32.00MB, used=3D36.00KB
Metadata, DUP: total=3D4.75GB, used=3D297.77MB

I also used the status command which was working correctly.
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Re: [PATCH 00/21] Btrfs: restriper

[Ilya Dryomov]

On Mon, Feb 13, 2012 at 09:31:09PM -0500, J=C3=A9r=C3=B4me Poulin wrote=
:
> On Fri, Jan 6, 2012 at 9:30 AM, Ilya Dryomov <idryomov@gmail.com> wro=
te:
> > This is a respin of restriper patch series which adds an initial
> > implementation of restriper (it's a clever name for relocation fram=
ework
> > that allows to do selective profile changing and selective balancin=
g
> > with some goodies like pausing/resuming and reporting progress to t=
he
> > user). =C2=A0See userspace cover patch for usage examples.
>=20
> I just tried merging this on my kernel 3.2.1 and it seems to work
> nicely. I compiled your btrfs-progs, made an LVM snapshot and launche=
d
> a balance on my 300 GB filesystem converted from ext4. It worked for
> converting my metadata from single to dup, however, it didn't succeed
> converting my system from single to dup.
>=20
> Here is the command I used:
> root /usr/src/kernel/btrfs-progs # ./btrfs balance start -f -v
> -sconvert=3Ddup -mconvert=3Ddup /mnt/btrfs/
> Dumping filters: flags 0xe, state 0x0, force is on
>   METADATA (flags 0x100): converting, target=3D32, soft is off
>   SYSTEM (flags 0x100): converting, target=3D32, soft is off
> Done, had to relocate 28 out of 220 chunks
>=20
> Then tried:
> root /usr/src/kernel/btrfs-progs # ./btrfs balance start -f -v
> -sconvert=3Ddup /mnt/btrfs/
> Dumping filters: flags 0xa, state 0x0, force is on
>   SYSTEM (flags 0x100): converting, target=3D32, soft is off
> Done, had to relocate 0 out of 239 chunks

Yeah, that's known.  The old balancing code wasn't allowed to relocate
chunk 0 and always skipped it.  I decided to keep that limitation, it
will be lifted (or otherwise fixed) shortly.

Just to be sure, could you please paste the output of
`btrfs-debug-tree -d <your device>' somewhere ?

Thanks,

		Ilya
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Re: [PATCH 00/21] Btrfs: restriper

[Jérôme Poulin]

On Tue, Feb 14, 2012 at 9:18 AM, Ilya Dryomov <idryomov@gmail.com> wrote:
>
> Just to be sure, could you please paste the output of
> `btrfs-debug-tree -d <your device>' somewhere ?

Here it is: http://paste.pocoo.org/show/550900/

I also had btrsck errors before and still have them with 3 new after
balance (I guess it duplicated them :)
root 424 inode 291690 errors 400
root 424 inode 18446744073709551604 errors 2000
root 424 inode 18446744073709551605 errors 1

Full btrfsck: http://paste.pocoo.org/show/550902/

Re: [PATCH 00/21] Btrfs: restriper

[Ilya Dryomov]

On Tue, Feb 14, 2012 at 11:15:39AM -0500, J=C3=A9r=C3=B4me Poulin wrote=
:
> On Tue, Feb 14, 2012 at 9:18 AM, Ilya Dryomov <idryomov@gmail.com> wr=
ote:
> >
> > Just to be sure, could you please paste the output of
> > `btrfs-debug-tree -d <your device>' somewhere ?
>=20
> Here it is: http://paste.pocoo.org/show/550900/

So I was correct, you have one system chunk, and it happens to start at
logical 0.  Balancing code simply skips it, I'll fix that.

Thanks,

		Ilya
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