[PATCH 00/22] btrfs-progs: extent tree v2 support, global roots

[PATCH 00/22] btrfs-progs: extent tree v2 support, global roots

[Josef Bacik]

Hello,

These patches are the first chunk of the extent tree v2 format changes.  This
includes the separate block group root which will hold all of the block group
items.  This also includes the global root support, which is the work to allow
us to have multiple extent, csum, and free space trees in the same file system.

The goal of these two changes are straightforward.  For the block group root, on
very large file systems the block group items are very widely separated, which
means it takes a very long time to mount the file system on large, slow disks.
Putting the block group items in their own root will allow us to densely
populate the tree and dramatically increase mount times in these cases.

The global roots change is motivated by lock contention on the root nodes of
these global roots.  I've had to make many changes to how we run delayed refs to
speed up things like the transaction commit because of all the delayed refs
going into one tree and contending on the root node of the extent tree.  In the
same token you can have heavy lock contention on the csum roots when writing to
many files.  Allowing for multiple roots will let us spread the lock contention
load around.

I have disabled a few key features, namely balance and qgroups.  There will be
more to come as I make more and more invasive changes, and then they will slowly
be re-enabled as the work is added.  These are disabled to avoid a bunch of work
that would be thrown away by future changes.

These patches have passed xfstests without panicing, but clearly failing a lot
of tests because of the disabled features.  I've also run it through fsperf to
validate that there are no major performance regressions.

WARNING: there are many more format changes planned, this is just the first
batch.  If you want to test then please feel free, but know that the format is
still in flux.  Thanks,

Josef

Josef Bacik (22):
  btrfs-progs: common: allow users to select extent-tree-v2 option
  btrfs-progs: add definitions for the block group tree
  btrfs-progs: add on disk pointers to global tree ids
  btrfs-progs: add support for loading the block group root
  btrfs-progs: add print support for the block group tree
  btrfs-progs: mkfs: use the btrfs_block_group_root helper
  btrfs-progs: check-lowmem: use the btrfs_block_group_root helper
  btrfs-progs: handle no bg item in extent tree for free space tree
  btrfs-progs: mkfs: add support for the block group tree
  btrfs-progs: check: add block group tree support
  btrfs-progs: qgroup-verify: scan extents based on block groups
  btrfs-progs: check: make free space tree validation extent tree v2
    aware
  btrfs-progs: check: add helper to reinit the root based on a key
  btrfs-progs: check: handle the block group tree properly
  btrfs-progs: load the number of global roots into the fs_info
  btrfs-progs: handle the per-block group global root id
  btrfs-progs: add a btrfs_delete_and_free_root helper
  btrfs-progs: make btrfs_clear_free_space_tree extent tree v2 aware
  btrfs-progs: make btrfs_create_tree take a key for the root key
  btrfs-progs: mkfs: set chunk_item_objectid properly for extent tree v2
  btrfs-progs: mkfs: create the global root's
  btrfs-progs: check: don't do the root item check for extent tree v2

 check/main.c                    | 233 ++++++++++++++------------
 check/mode-lowmem.c             |  12 +-
 check/qgroup-verify.c           |  32 +++-
 cmds/inspect-dump-tree.c        |  37 ++++-
 common/fsfeatures.c             |  11 ++
 common/repair.c                 |   3 +
 kernel-shared/ctree.h           |  66 +++++++-
 kernel-shared/disk-io.c         | 282 ++++++++++++++++++++++++++------
 kernel-shared/disk-io.h         |  15 +-
 kernel-shared/extent-tree.c     |  25 ++-
 kernel-shared/free-space-tree.c |  72 ++++----
 kernel-shared/print-tree.c      |  26 ++-
 kernel-shared/transaction.c     |   2 +
 libbtrfsutil/btrfs_tree.h       |   3 +
 mkfs/common.c                   |  93 ++++++++---
 mkfs/common.h                   |  12 ++
 mkfs/main.c                     |  94 ++++++++++-
 17 files changed, 779 insertions(+), 239 deletions(-)

-- 
2.26.3

[PATCH 01/22] btrfs-progs: common: allow users to select extent-tree-v2 option

[Josef Bacik]

We want to enable developers to test the extent tree v2 features as they
are added, add the ability to mkfs an extent tree v2 fs if we have
experimental enabled.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 common/fsfeatures.c   | 11 +++++++++++
 kernel-shared/ctree.h | 18 ++++++++++++++++++
 mkfs/main.c           |  6 ++++++
 3 files changed, 35 insertions(+)

diff --git a/common/fsfeatures.c b/common/fsfeatures.c
index df1bb8f7..23a92c21 100644
--- a/common/fsfeatures.c
+++ b/common/fsfeatures.c
@@ -131,6 +131,17 @@ static const struct btrfs_feature mkfs_features[] = {
 		VERSION_NULL(default),
 		.desc		= "support zoned devices"
 	},
+#endif
+#if EXPERIMENTAL
+	{
+		.name		= "extent-tree-v2",
+		.flag		= BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2,
+		.sysfs_name	= "extent_tree_v2",
+		VERSION_TO_STRING2(compat, 5,15),
+		VERSION_NULL(safe),
+		VERSION_NULL(default),
+		.desc		= "new extent tree format"
+	},
 #endif
 	/* Keep this one last */
 	{
diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
index 12a8165d..8a46306e 100644
--- a/kernel-shared/ctree.h
+++ b/kernel-shared/ctree.h
@@ -507,6 +507,23 @@ struct btrfs_super_block {
 	(BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE |	\
 	 BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID)
 
+#if EXPERIMENTAL
+#define BTRFS_FEATURE_INCOMPAT_SUPP			\
+	(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |		\
+	 BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |	\
+	 BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |		\
+	 BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD |		\
+	 BTRFS_FEATURE_INCOMPAT_BIG_METADATA |		\
+	 BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |		\
+	 BTRFS_FEATURE_INCOMPAT_RAID56 |		\
+	 BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |		\
+	 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |	\
+	 BTRFS_FEATURE_INCOMPAT_NO_HOLES |		\
+	 BTRFS_FEATURE_INCOMPAT_RAID1C34 |		\
+	 BTRFS_FEATURE_INCOMPAT_METADATA_UUID |		\
+	 BTRFS_FEATURE_INCOMPAT_ZONED |			\
+	 BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2)
+#else
 #define BTRFS_FEATURE_INCOMPAT_SUPP			\
 	(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |		\
 	 BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |	\
@@ -521,6 +538,7 @@ struct btrfs_super_block {
 	 BTRFS_FEATURE_INCOMPAT_RAID1C34 |		\
 	 BTRFS_FEATURE_INCOMPAT_METADATA_UUID |		\
 	 BTRFS_FEATURE_INCOMPAT_ZONED)
+#endif
 
 /*
  * A leaf is full of items. offset and size tell us where to find
diff --git a/mkfs/main.c b/mkfs/main.c
index d0c863fd..2c4b7b00 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -1223,6 +1223,12 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
 		features |= BTRFS_FEATURE_INCOMPAT_RAID1C34;
 	}
 
+	/* Extent tree v2 comes with a set of mandatory features. */
+	if (features & BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2) {
+		features |= BTRFS_FEATURE_INCOMPAT_NO_HOLES;
+		runtime_features |= BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE;
+	}
+
 	if (zoned) {
 		if (source_dir_set) {
 			error("the option -r and zoned mode are incompatible");
-- 
2.26.3

[PATCH 02/22] btrfs-progs: add definitions for the block group tree

[Josef Bacik]

Add the on disk definitions for the block group tree.  This will be part
of the super block so we need to add the appropriate helpers to the
super block, as well as adding it to the backup roots.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 cmds/inspect-dump-tree.c   |  7 ++++++-
 kernel-shared/ctree.h      | 29 ++++++++++++++++++++++++++++-
 kernel-shared/disk-io.c    | 14 ++++++++++++++
 kernel-shared/print-tree.c |  3 +++
 libbtrfsutil/btrfs_tree.h  |  3 +++
 5 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/cmds/inspect-dump-tree.c b/cmds/inspect-dump-tree.c
index e1c90be7..6332b46d 100644
--- a/cmds/inspect-dump-tree.c
+++ b/cmds/inspect-dump-tree.c
@@ -155,7 +155,8 @@ static u64 treeid_from_string(const char *str, const char **end)
 		{ "TREE_LOG_FIXUP", BTRFS_TREE_LOG_FIXUP_OBJECTID },
 		{ "TREE_LOG", BTRFS_TREE_LOG_OBJECTID },
 		{ "TREE_RELOC", BTRFS_TREE_RELOC_OBJECTID },
-		{ "DATA_RELOC", BTRFS_DATA_RELOC_TREE_OBJECTID }
+		{ "DATA_RELOC", BTRFS_DATA_RELOC_TREE_OBJECTID },
+		{ "BLOCK_GROUP_TREE", BTRFS_BLOCK_GROUP_TREE_OBJECTID },
 	};
 
 	if (strncasecmp("BTRFS_", str, strlen("BTRFS_")) == 0)
@@ -695,6 +696,10 @@ again:
 					printf("multiple");
 				}
 				break;
+			case BTRFS_BLOCK_GROUP_TREE_OBJECTID:
+				if (!skip)
+					printf("block group");
+				break;
 			default:
 				if (!skip) {
 					printf("file");
diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
index 8a46306e..17216053 100644
--- a/kernel-shared/ctree.h
+++ b/kernel-shared/ctree.h
@@ -85,6 +85,9 @@ struct btrfs_free_space_ctl;
 /* tracks free space in block groups. */
 #define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
 
+/* hold the block group items. */
+#define BTRFS_BLOCK_GROUP_TREE_OBJECTID 11ULL
+
 /* device stats in the device tree */
 #define BTRFS_DEV_STATS_OBJECTID 0ULL
 
@@ -456,8 +459,14 @@ struct btrfs_super_block {
 	__le64 uuid_tree_generation;
 
 	u8 metadata_uuid[BTRFS_FSID_SIZE];
+
+	__le64 block_group_root;
+	__le64 block_group_root_generation;
+	u8 block_group_root_level;
+
 	/* future expansion */
-	__le64 reserved[28];
+	u8 reserved8[7];
+	__le64 reserved[25];
 	u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
 	struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
 } __attribute__ ((__packed__));
@@ -2281,6 +2290,17 @@ 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);
 
+/*
+ * Extent tree v2 doesn't have a global csum or extent root, so we use the
+ * extent root slot for the block group root.
+ */
+BTRFS_SETGET_STACK_FUNCS(backup_block_group_root, struct btrfs_root_backup,
+		   extent_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_block_group_root_gen, struct btrfs_root_backup,
+		   extent_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_block_group_root_level, struct btrfs_root_backup,
+		   extent_root_level, 8);
+
 /* struct btrfs_super_block */
 
 BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);
@@ -2331,6 +2351,13 @@ BTRFS_SETGET_STACK_FUNCS(super_cache_generation, struct btrfs_super_block,
 BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
 			 uuid_tree_generation, 64);
 BTRFS_SETGET_STACK_FUNCS(super_magic, struct btrfs_super_block, magic, 64);
+BTRFS_SETGET_STACK_FUNCS(super_block_group_root, struct btrfs_super_block,
+			 block_group_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_block_group_root_generation,
+			 struct btrfs_super_block,
+			 block_group_root_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_block_group_root_level,
+			 struct btrfs_super_block, block_group_root_level, 8);
 
 static inline unsigned long btrfs_leaf_data(struct extent_buffer *l)
 {
diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
index 981ac4f8..bea42556 100644
--- a/kernel-shared/disk-io.c
+++ b/kernel-shared/disk-io.c
@@ -1704,6 +1704,20 @@ int btrfs_check_super(struct btrfs_super_block *sb, unsigned sbflags)
 		goto error_out;
 	}
 
+	if (btrfs_super_incompat_flags(sb) & BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2) {
+		if (btrfs_super_block_group_root_level(sb) >= BTRFS_MAX_LEVEL) {
+			error("block_group_root level too big: %d >= %d",
+			      btrfs_super_block_group_root_level(sb),
+			      BTRFS_MAX_LEVEL);
+			goto error_out;
+		}
+		if (!IS_ALIGNED(btrfs_super_block_group_root(sb), 4096)) {
+			error("block_group_root block unaligned: %llu",
+			      btrfs_super_block_group_root(sb));
+			goto error_out;
+		}
+	}
+
 	if (btrfs_super_incompat_flags(sb) & BTRFS_FEATURE_INCOMPAT_METADATA_UUID)
 		metadata_uuid = sb->metadata_uuid;
 	else
diff --git a/kernel-shared/print-tree.c b/kernel-shared/print-tree.c
index 39655590..6748c33f 100644
--- a/kernel-shared/print-tree.c
+++ b/kernel-shared/print-tree.c
@@ -787,6 +787,9 @@ void print_objectid(FILE *stream, u64 objectid, u8 type)
 	case BTRFS_MULTIPLE_OBJECTIDS:
 		fprintf(stream, "MULTIPLE");
 		break;
+	case BTRFS_BLOCK_GROUP_TREE_OBJECTID:
+		fprintf(stream, "BLOCK_GROUP_TREE");
+		break;
 	case (u64)-1:
 		fprintf(stream, "-1");
 		break;
diff --git a/libbtrfsutil/btrfs_tree.h b/libbtrfsutil/btrfs_tree.h
index d3b752ee..1df9efd6 100644
--- a/libbtrfsutil/btrfs_tree.h
+++ b/libbtrfsutil/btrfs_tree.h
@@ -48,6 +48,9 @@
 /* tracks free space in block groups. */
 #define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
 
+/* hold the block group items. */
+#define BTRFS_BLOCK_GROUP_TREE_OBJECTID 11ULL
+
 /* device stats in the device tree */
 #define BTRFS_DEV_STATS_OBJECTID 0ULL
 
-- 
2.26.3

[PATCH 03/22] btrfs-progs: add on disk pointers to global tree ids

[Josef Bacik]

We are going to start creating multiple sets of global trees, which at
the moment are the free space tree, csum tree, and extent tree.
Generally we will assign these at block group creation time, but Dave
would like to be able to have them per-subvolume at some point, so
reserve a slot for that as well.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/ctree.h | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
index 17216053..e54e03c4 100644
--- a/kernel-shared/ctree.h
+++ b/kernel-shared/ctree.h
@@ -824,7 +824,13 @@ struct btrfs_root_item {
 	struct btrfs_timespec otime;
 	struct btrfs_timespec stime;
 	struct btrfs_timespec rtime;
-        __le64 reserved[8]; /* for future */
+
+	/*
+	 * If we want to use a specific set of fst/checksum/extent roots for
+	 * this root.
+	 */
+	__le64 global_tree_id;
+        __le64 reserved[7]; /* for future */
 } __attribute__ ((__packed__));
 
 /*
@@ -1709,6 +1715,12 @@ BTRFS_SETGET_FUNCS(block_group_flags,
 BTRFS_SETGET_STACK_FUNCS(stack_block_group_flags,
 			struct btrfs_block_group_item, flags, 64);
 
+/* extent tree v2 uses chunk_objectid for the global tree id. */
+BTRFS_SETGET_STACK_FUNCS(stack_block_group_global_tree_id,
+			 struct btrfs_block_group_item, chunk_objectid, 64);
+BTRFS_SETGET_FUNCS(block_group_global_tree_id, struct btrfs_block_group_item,
+		   chunk_objectid, 64);
+
 /* struct btrfs_free_space_info */
 BTRFS_SETGET_FUNCS(free_space_extent_count, struct btrfs_free_space_info,
 		   extent_count, 32);
-- 
2.26.3

[PATCH 04/22] btrfs-progs: add support for loading the block group root

[Josef Bacik]

This adds the ability to load the block group root, as well as make sure
the various backup super block and super block updates are made
appropriately.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/ctree.h       |   1 +
 kernel-shared/disk-io.c     | 156 +++++++++++++++++++++++++++---------
 kernel-shared/disk-io.h     |  10 ++-
 kernel-shared/extent-tree.c |   8 +-
 kernel-shared/transaction.c |   2 +
 5 files changed, 135 insertions(+), 42 deletions(-)

diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
index e54e03c4..27e31e03 100644
--- a/kernel-shared/ctree.h
+++ b/kernel-shared/ctree.h
@@ -1195,6 +1195,7 @@ struct btrfs_fs_info {
 	struct btrfs_root *dev_root;
 	struct btrfs_root *quota_root;
 	struct btrfs_root *uuid_root;
+	struct btrfs_root *block_group_root;
 
 	struct rb_root global_roots_tree;
 	struct rb_root fs_root_tree;
diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
index bea42556..38741819 100644
--- a/kernel-shared/disk-io.c
+++ b/kernel-shared/disk-io.c
@@ -838,6 +838,9 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 		root = btrfs_global_root(fs_info, location);
 		return root ? root : ERR_PTR(-ENOENT);
 	}
+	if (location->objectid == BTRFS_BLOCK_GROUP_TREE_OBJECTID)
+		return fs_info->block_group_root ? fs_info->block_group_root :
+						ERR_PTR(-ENOENT);
 
 	BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID);
 
@@ -876,6 +879,7 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
 	free(fs_info->chunk_root);
 	free(fs_info->dev_root);
 	free(fs_info->uuid_root);
+	free(fs_info->block_group_root);
 	free(fs_info->super_copy);
 	free(fs_info->log_root_tree);
 	free(fs_info);
@@ -894,10 +898,12 @@ struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
 	fs_info->dev_root = calloc(1, sizeof(struct btrfs_root));
 	fs_info->quota_root = calloc(1, sizeof(struct btrfs_root));
 	fs_info->uuid_root = calloc(1, sizeof(struct btrfs_root));
+	fs_info->block_group_root = calloc(1, sizeof(struct btrfs_root));
 	fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
 
 	if (!fs_info->tree_root || !fs_info->chunk_root || !fs_info->dev_root ||
-	    !fs_info->quota_root || !fs_info->uuid_root || !fs_info->super_copy)
+	    !fs_info->quota_root || !fs_info->uuid_root ||
+	    !fs_info->block_group_root || !fs_info->super_copy)
 		goto free_all;
 
 	extent_io_tree_init(&fs_info->extent_cache);
@@ -1016,7 +1022,7 @@ static int read_root_or_create_block(struct btrfs_fs_info *fs_info,
 static inline bool maybe_load_block_groups(struct btrfs_fs_info *fs_info,
 					   u64 flags)
 {
-	struct btrfs_root *root = btrfs_extent_root(fs_info, 0);
+	struct btrfs_root *root = btrfs_block_group_root(fs_info);
 
 	if (flags & OPEN_CTREE_NO_BLOCK_GROUPS)
 		return false;
@@ -1027,7 +1033,6 @@ static inline bool maybe_load_block_groups(struct btrfs_fs_info *fs_info,
 	return false;
 }
 
-
 static int load_global_roots_objectid(struct btrfs_fs_info *fs_info,
 				      struct btrfs_path *path, u64 objectid,
 				      unsigned flags, char *str)
@@ -1125,39 +1130,94 @@ out:
 	return ret;
 }
 
-int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
-			  unsigned flags)
+static int load_important_roots(struct btrfs_fs_info *fs_info,
+				u64 root_tree_bytenr, unsigned flags)
 {
 	struct btrfs_super_block *sb = fs_info->super_copy;
+	struct btrfs_root_backup *backup = NULL;
 	struct btrfs_root *root;
-	struct btrfs_key key;
-	u64 generation;
+	u64 bytenr, gen;
+	int index = -1;
 	int ret;
 
-	root = fs_info->tree_root;
-	btrfs_setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
-	generation = btrfs_super_generation(sb);
-
-	if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
-		root_tree_bytenr = btrfs_super_root(sb);
-	} else if (flags & OPEN_CTREE_BACKUP_ROOT) {
-		struct btrfs_root_backup *backup;
-		int index = find_best_backup_root(sb);
+	if (flags & OPEN_CTREE_BACKUP_ROOT) {
+		index = find_best_backup_root(sb);
 		if (index >= BTRFS_NUM_BACKUP_ROOTS) {
 			fprintf(stderr, "Invalid backup root number\n");
 			return -EIO;
 		}
-		backup = fs_info->super_copy->super_roots + index;
-		root_tree_bytenr = btrfs_backup_tree_root(backup);
-		generation = btrfs_backup_tree_root_gen(backup);
+		backup = sb->super_roots + index;
+	}
+
+	if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		free(fs_info->block_group_root);
+		fs_info->block_group_root = NULL;
+		goto tree_root;
+	}
+
+	if (backup) {
+		bytenr = btrfs_backup_block_group_root(backup);
+		gen = btrfs_backup_block_group_root_gen(backup);
+	} else {
+		bytenr = btrfs_super_block_group_root(sb);
+		gen = btrfs_super_block_group_root_generation(sb);
+	}
+	root = fs_info->block_group_root;
+	btrfs_setup_root(root, fs_info, BTRFS_BLOCK_GROUP_TREE_OBJECTID);
+
+	ret = read_root_node(fs_info, root, bytenr, gen);
+	if (ret) {
+		fprintf(stderr, "Couldn't read block group root\n");
+		return -EIO;
+	}
+
+	if (maybe_load_block_groups(fs_info, flags)) {
+		int ret = btrfs_read_block_groups(fs_info);
+		if (ret < 0 && ret != -ENOENT) {
+			errno = -ret;
+			error("failed to read block groups: %m");
+			return ret;
+		}
+	}
+
+tree_root:
+	if (backup) {
+		bytenr = btrfs_backup_tree_root(backup);
+		gen = btrfs_backup_tree_root_gen(backup);
+	} else {
+		if (root_tree_bytenr)
+			bytenr = root_tree_bytenr;
+		else
+			bytenr = btrfs_super_root(sb);
+		gen = btrfs_super_generation(sb);
 	}
 
-	ret = read_root_node(fs_info, root, root_tree_bytenr, generation);
+	fs_info->generation = gen;
+	fs_info->last_trans_committed = gen;
+	root = fs_info->tree_root;
+	btrfs_setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
+
+	ret = read_root_node(fs_info, root, bytenr, gen);
 	if (ret) {
 		fprintf(stderr, "Couldn't read tree root\n");
 		return -EIO;
 	}
 
+	return 0;
+}
+
+int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
+			  unsigned flags)
+{
+	struct btrfs_super_block *sb = fs_info->super_copy;
+	struct btrfs_root *root = fs_info->tree_root;
+	struct btrfs_key key;
+	int ret;
+
+	ret = load_important_roots(fs_info, root_tree_bytenr, flags);
+	if (ret)
+		return ret;
+
 	ret = load_global_roots(fs_info, flags);
 	if (ret)
 		return ret;
@@ -1195,9 +1255,8 @@ int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
 			return -EIO;
 	}
 
-	fs_info->generation = generation;
-	fs_info->last_trans_committed = generation;
-	if (maybe_load_block_groups(fs_info, flags)) {
+	if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2) &&
+	    maybe_load_block_groups(fs_info, flags)) {
 		ret = btrfs_read_block_groups(fs_info);
 		/*
 		 * If we don't find any blockgroups (ENOENT) we're either
@@ -1240,6 +1299,8 @@ static void release_global_roots(struct btrfs_fs_info *fs_info)
 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info)
 {
 	release_global_roots(fs_info);
+	if (fs_info->block_group_root)
+		free_extent_buffer(fs_info->block_group_root->node);
 	if (fs_info->quota_root)
 		free_extent_buffer(fs_info->quota_root->node);
 	if (fs_info->dev_root)
@@ -1979,8 +2040,6 @@ static int write_dev_supers(struct btrfs_fs_info *fs_info,
 static void backup_super_roots(struct btrfs_fs_info *info)
 {
 	struct btrfs_root_backup *root_backup;
-	struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
-	struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
 	int next_backup;
 	int last_backup;
 
@@ -2012,11 +2071,6 @@ static void backup_super_roots(struct btrfs_fs_info *info)
 	btrfs_set_backup_chunk_root_level(root_backup,
 			       btrfs_header_level(info->chunk_root->node));
 
-	btrfs_set_backup_extent_root(root_backup, extent_root->node->start);
-	btrfs_set_backup_extent_root_gen(root_backup,
-			       btrfs_header_generation(extent_root->node));
-	btrfs_set_backup_extent_root_level(root_backup,
-			       btrfs_header_level(extent_root->node));
 	/*
 	 * we might commit during log recovery, which happens before we set
 	 * the fs_root.  Make sure it is valid before we fill it in.
@@ -2036,18 +2090,37 @@ static void backup_super_roots(struct btrfs_fs_info *info)
 	btrfs_set_backup_dev_root_level(root_backup,
 				       btrfs_header_level(info->dev_root->node));
 
-	btrfs_set_backup_csum_root(root_backup, csum_root->node->start);
-	btrfs_set_backup_csum_root_gen(root_backup,
-			       btrfs_header_generation(csum_root->node));
-	btrfs_set_backup_csum_root_level(root_backup,
-			       btrfs_header_level(csum_root->node));
-
 	btrfs_set_backup_total_bytes(root_backup,
 			     btrfs_super_total_bytes(info->super_copy));
 	btrfs_set_backup_bytes_used(root_backup,
 			     btrfs_super_bytes_used(info->super_copy));
 	btrfs_set_backup_num_devices(root_backup,
 			     btrfs_super_num_devices(info->super_copy));
+
+	if (btrfs_fs_incompat(info, EXTENT_TREE_V2)) {
+		btrfs_set_backup_block_group_root(root_backup,
+				info->block_group_root->node->start);
+		btrfs_set_backup_block_group_root_gen(root_backup,
+			btrfs_header_generation(info->block_group_root->node));
+		btrfs_set_backup_block_group_root_level(root_backup,
+			btrfs_header_level(info->block_group_root->node));
+	} else {
+		struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
+		struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
+
+		btrfs_set_backup_csum_root(root_backup, csum_root->node->start);
+		btrfs_set_backup_csum_root_gen(root_backup,
+				btrfs_header_generation(csum_root->node));
+		btrfs_set_backup_csum_root_level(root_backup,
+				btrfs_header_level(csum_root->node));
+
+		btrfs_set_backup_extent_root(root_backup,
+					     extent_root->node->start);
+		btrfs_set_backup_extent_root_gen(root_backup,
+			btrfs_header_generation(extent_root->node));
+		btrfs_set_backup_extent_root_level(root_backup,
+			btrfs_header_level(extent_root->node));
+	}
 }
 
 int write_all_supers(struct btrfs_fs_info *fs_info)
@@ -2094,7 +2167,7 @@ int write_ctree_super(struct btrfs_trans_handle *trans)
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_root *tree_root = fs_info->tree_root;
 	struct btrfs_root *chunk_root = fs_info->chunk_root;
-
+	struct btrfs_root *block_group_root = fs_info->block_group_root;
 	if (fs_info->readonly)
 		return 0;
 
@@ -2111,6 +2184,15 @@ int write_ctree_super(struct btrfs_trans_handle *trans)
 	btrfs_set_super_chunk_root_generation(fs_info->super_copy,
 				btrfs_header_generation(chunk_root->node));
 
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_set_super_block_group_root(fs_info->super_copy,
+						 block_group_root->node->start);
+		btrfs_set_super_block_group_root_generation(fs_info->super_copy,
+				btrfs_header_generation(block_group_root->node));
+		btrfs_set_super_block_group_root_level(fs_info->super_copy,
+				btrfs_header_level(block_group_root->node));
+	}
+
 	ret = write_all_supers(fs_info);
 	if (ret)
 		fprintf(stderr, "failed to write new super block err %d\n", ret);
diff --git a/kernel-shared/disk-io.h b/kernel-shared/disk-io.h
index 0d2f505f..a96a9dfb 100644
--- a/kernel-shared/disk-io.h
+++ b/kernel-shared/disk-io.h
@@ -219,9 +219,17 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 				     u64 objectid);
 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_inf, u64 bytenr);
-struct btrfs_root *btrfs_block_group_root(struct btrfs_fs_info *fs_info);
 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
 				     struct btrfs_key *key);
 int btrfs_global_root_insert(struct btrfs_fs_info *fs_info,
 			     struct btrfs_root *root);
+
+static inline struct btrfs_root *btrfs_block_group_root(
+						struct btrfs_fs_info *fs_info)
+{
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+		return fs_info->block_group_root;
+	return btrfs_extent_root(fs_info, 0);
+}
+
 #endif
diff --git a/kernel-shared/extent-tree.c b/kernel-shared/extent-tree.c
index 3713452b..a1c061fa 100644
--- a/kernel-shared/extent-tree.c
+++ b/kernel-shared/extent-tree.c
@@ -1540,7 +1540,7 @@ static int update_block_group_item(struct btrfs_trans_handle *trans,
 {
 	int ret;
 	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_root *root = btrfs_extent_root(fs_info, 0);
+	struct btrfs_root *root = btrfs_block_group_root(fs_info);
 	unsigned long bi;
 	struct btrfs_block_group_item bgi;
 	struct extent_buffer *leaf;
@@ -2731,7 +2731,7 @@ int btrfs_read_block_groups(struct btrfs_fs_info *fs_info)
 	int ret;
 	struct btrfs_key key;
 
-	root = btrfs_extent_root(fs_info, 0);
+	root = btrfs_block_group_root(fs_info);
 	key.objectid = 0;
 	key.offset = 0;
 	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
@@ -2812,7 +2812,7 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans,
 	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
 	key.offset = block_group->length;
 
-	root = btrfs_extent_root(fs_info, 0);
+	root = btrfs_block_group_root(fs_info);
 	return btrfs_insert_item(trans, root, &key, &bgi, sizeof(bgi));
 }
 
@@ -2929,7 +2929,7 @@ static int remove_block_group_item(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_key key;
-	struct btrfs_root *root = btrfs_extent_root(fs_info, 0);
+	struct btrfs_root *root = btrfs_block_group_root(fs_info);
 	int ret = 0;
 
 	key.objectid = block_group->start;
diff --git a/kernel-shared/transaction.c b/kernel-shared/transaction.c
index 5b991651..02012266 100644
--- a/kernel-shared/transaction.c
+++ b/kernel-shared/transaction.c
@@ -185,6 +185,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 		goto commit_tree;
 	if (root == root->fs_info->chunk_root)
 		goto commit_tree;
+	if (root == root->fs_info->block_group_root)
+		goto commit_tree;
 
 	free_extent_buffer(root->commit_root);
 	root->commit_root = NULL;
-- 
2.26.3

[PATCH 05/22] btrfs-progs: add print support for the block group tree

[Josef Bacik]

Add the appropriate support to the print tree and dump tree code to spit
out the block group tree.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 cmds/inspect-dump-tree.c   | 30 +++++++++++++++++++++++++++++-
 kernel-shared/print-tree.c | 23 +++++++++++++++++++----
 2 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/cmds/inspect-dump-tree.c b/cmds/inspect-dump-tree.c
index 6332b46d..daa7f925 100644
--- a/cmds/inspect-dump-tree.c
+++ b/cmds/inspect-dump-tree.c
@@ -83,8 +83,14 @@ out:
 
 static void print_old_roots(struct btrfs_super_block *super)
 {
+	const char *extent_tree_str = "extent root";
 	struct btrfs_root_backup *backup;
 	int i;
+	bool extent_tree_v2 = (btrfs_super_incompat_flags(super) &
+		BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2);
+
+	if (extent_tree_v2)
+		extent_tree_str = "block group root";
 
 	for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
 		backup = super->super_roots + i;
@@ -93,7 +99,7 @@ static void print_old_roots(struct btrfs_super_block *super)
 		       (unsigned long long)btrfs_backup_tree_root_gen(backup),
 		       (unsigned long long)btrfs_backup_tree_root(backup));
 
-		printf("\t\textent root gen %llu block %llu\n",
+		printf("\t\t%s gen %llu block %llu\n", extent_tree_str,
 		       (unsigned long long)btrfs_backup_extent_root_gen(backup),
 		       (unsigned long long)btrfs_backup_extent_root(backup));
 
@@ -510,6 +516,11 @@ static int cmd_inspect_dump_tree(const struct cmd_struct *cmd,
 				       info->log_root_tree->node->start,
 					btrfs_header_level(
 						info->log_root_tree->node));
+			if (info->block_group_root)
+				printf("block group tree: %llu level %d\n",
+				       info->block_group_root->node->start,
+					btrfs_header_level(
+						info->block_group_root->node));
 		} else {
 			if (info->tree_root->node) {
 				printf("root tree\n");
@@ -528,6 +539,12 @@ static int cmd_inspect_dump_tree(const struct cmd_struct *cmd,
 				btrfs_print_tree(info->log_root_tree->node,
 					BTRFS_PRINT_TREE_FOLLOW | print_mode);
 			}
+
+			if (info->block_group_root) {
+				printf("block group tree\n");
+				btrfs_print_tree(info->block_group_root->node,
+					BTRFS_PRINT_TREE_FOLLOW | print_mode);
+			}
 		}
 	}
 	tree_root_scan = info->tree_root;
@@ -573,6 +590,17 @@ again:
 		goto close_root;
 	}
 
+	if (tree_id && tree_id == BTRFS_BLOCK_GROUP_TREE_OBJECTID) {
+		if (!info->block_group_root) {
+			error("cannot print block group tree, invalid pointer");
+			goto close_root;
+		}
+		printf("block group tree\n");
+		btrfs_print_tree(info->block_group_root->node,
+					BTRFS_PRINT_TREE_FOLLOW | print_mode);
+		goto close_root;
+	}
+
 	key.offset = 0;
 	key.objectid = 0;
 	key.type = BTRFS_ROOT_ITEM_KEY;
diff --git a/kernel-shared/print-tree.c b/kernel-shared/print-tree.c
index 6748c33f..d2699e6c 100644
--- a/kernel-shared/print-tree.c
+++ b/kernel-shared/print-tree.c
@@ -1860,8 +1860,14 @@ static int empty_backup(struct btrfs_root_backup *backup)
 	return 0;
 }
 
-static void print_root_backup(struct btrfs_root_backup *backup)
+static void print_root_backup(struct btrfs_root_backup *backup,
+			      bool extent_tree_v2)
 {
+	const char *extent_tree_str = "backup_extent_root";
+
+	if (extent_tree_v2)
+		extent_tree_str = "backup_block_group_root";
+
 	printf("\t\tbackup_tree_root:\t%llu\tgen: %llu\tlevel: %d\n",
 			btrfs_backup_tree_root(backup),
 			btrfs_backup_tree_root_gen(backup),
@@ -1870,7 +1876,8 @@ static void print_root_backup(struct btrfs_root_backup *backup)
 			btrfs_backup_chunk_root(backup),
 			btrfs_backup_chunk_root_gen(backup),
 			btrfs_backup_chunk_root_level(backup));
-	printf("\t\tbackup_extent_root:\t%llu\tgen: %llu\tlevel: %d\n",
+	printf("\t\t%s:\t%llu\tgen: %llu\tlevel: %d\n",
+			extent_tree_str,
 			btrfs_backup_extent_root(backup),
 			btrfs_backup_extent_root_gen(backup),
 			btrfs_backup_extent_root_level(backup));
@@ -1882,7 +1889,7 @@ static void print_root_backup(struct btrfs_root_backup *backup)
 			btrfs_backup_dev_root(backup),
 			btrfs_backup_dev_root_gen(backup),
 			btrfs_backup_dev_root_level(backup));
-	printf("\t\tbackup_csum_root:\t%llu\tgen: %llu\tlevel: %d\n",
+	printf("\t\tcsum_root:\t%llu\tgen: %llu\tlevel: %d\n",
 			btrfs_backup_csum_root(backup),
 			btrfs_backup_csum_root_gen(backup),
 			btrfs_backup_csum_root_level(backup));
@@ -1900,12 +1907,14 @@ static void print_backup_roots(struct btrfs_super_block *sb)
 {
 	struct btrfs_root_backup *backup;
 	int i;
+	bool extent_tree_v2 = (btrfs_super_incompat_flags(sb) &
+		BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2);
 
 	for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
 		backup = sb->super_roots + i;
 		if (!empty_backup(backup)) {
 			printf("\tbackup %d:\n", i);
-			print_root_backup(backup);
+			print_root_backup(backup, extent_tree_v2);
 		}
 	}
 }
@@ -2022,6 +2031,12 @@ void btrfs_print_superblock(struct btrfs_super_block *sb, int full)
 	       (unsigned long long)btrfs_super_cache_generation(sb));
 	printf("uuid_tree_generation\t%llu\n",
 	       (unsigned long long)btrfs_super_uuid_tree_generation(sb));
+	printf("block_group_root\t%llu\n",
+	       (unsigned long long)btrfs_super_block_group_root(sb));
+	printf("block_group_root_generation\t%llu\n",
+	       (unsigned long long)btrfs_super_block_group_root_generation(sb));
+	printf("block_group_root_level\t%llu\n",
+	       (unsigned long long)btrfs_super_block_group_root_level(sb));
 
 	uuid_unparse(sb->dev_item.uuid, buf);
 	printf("dev_item.uuid\t\t%s\n", buf);
-- 
2.26.3

[PATCH 06/22] btrfs-progs: mkfs: use the btrfs_block_group_root helper

[Josef Bacik]

Instead of accessing the extent root directory for modifying block
groups, use the helper which will do the correct thing based on the
flags of the file system.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 check/main.c | 4 ++--
 mkfs/main.c  | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/check/main.c b/check/main.c
index 5fb28216..7735cce1 100644
--- a/check/main.c
+++ b/check/main.c
@@ -9387,6 +9387,7 @@ static int reinit_global_roots(struct btrfs_trans_handle *trans, u64 objectid)
 
 static int reinit_extent_tree(struct btrfs_trans_handle *trans, bool pin)
 {
+	struct btrfs_root *bg_root = btrfs_block_group_root(trans->fs_info);
 	u64 start = 0;
 	int ret;
 
@@ -9460,7 +9461,6 @@ again:
 	while (1) {
 		struct btrfs_block_group_item bgi;
 		struct btrfs_block_group *cache;
-		struct btrfs_root *extent_root = btrfs_extent_root(gfs_info, 0);
 		struct btrfs_key key;
 
 		cache = btrfs_lookup_first_block_group(gfs_info, start);
@@ -9474,7 +9474,7 @@ again:
 		key.objectid = cache->start;
 		key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
 		key.offset = cache->length;
-		ret = btrfs_insert_item(trans, extent_root, &key, &bgi,
+		ret = btrfs_insert_item(trans, bg_root, &key, &bgi,
 					sizeof(bgi));
 		if (ret) {
 			fprintf(stderr, "Error adding block group\n");
diff --git a/mkfs/main.c b/mkfs/main.c
index 2c4b7b00..9a57cef8 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -596,7 +596,7 @@ static int cleanup_temp_chunks(struct btrfs_fs_info *fs_info,
 {
 	struct btrfs_trans_handle *trans = NULL;
 	struct btrfs_block_group_item *bgi;
-	struct btrfs_root *root = btrfs_extent_root(fs_info, 0);
+	struct btrfs_root *root = btrfs_block_group_root(fs_info);
 	struct btrfs_key key;
 	struct btrfs_key found_key;
 	struct btrfs_path path;
-- 
2.26.3

[PATCH 07/22] btrfs-progs: check-lowmem: use the btrfs_block_group_root helper

[Josef Bacik]

When we're messing with block group items use the
btrfs_block_group_root() helper to get the correct root to search, and
this will do the right thing based on the file system flags.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 check/mode-lowmem.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
index cc6773cd..263b56d1 100644
--- a/check/mode-lowmem.c
+++ b/check/mode-lowmem.c
@@ -266,7 +266,7 @@ static int modify_block_group_cache(struct btrfs_block_group *block_group, int c
  */
 static int modify_block_groups_cache(u64 flags, int cache)
 {
-	struct btrfs_root *root = btrfs_extent_root(gfs_info, 0);
+	struct btrfs_root *root = btrfs_block_group_root(gfs_info);
 	struct btrfs_key key;
 	struct btrfs_path path;
 	struct btrfs_block_group *bg_cache;
@@ -331,7 +331,7 @@ static int clear_block_groups_full(u64 flags)
 static int create_chunk_and_block_group(u64 flags, u64 *start, u64 *nbytes)
 {
 	struct btrfs_trans_handle *trans;
-	struct btrfs_root *root = btrfs_extent_root(gfs_info, 0);
+	struct btrfs_root *root = btrfs_block_group_root(gfs_info);
 	int ret;
 
 	if ((flags & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0)
@@ -419,7 +419,7 @@ static int is_chunk_almost_full(u64 start)
 {
 	struct btrfs_path path;
 	struct btrfs_key key;
-	struct btrfs_root *root = btrfs_extent_root(gfs_info, 0);
+	struct btrfs_root *root = btrfs_block_group_root(gfs_info);
 	struct btrfs_block_group_item *bi;
 	struct btrfs_block_group_item bg_item;
 	struct extent_buffer *eb;
@@ -4591,7 +4591,7 @@ next:
 static int find_block_group_item(struct btrfs_path *path, u64 bytenr, u64 len,
 				 u64 type)
 {
-	struct btrfs_root *root = btrfs_extent_root(gfs_info, 0);
+	struct btrfs_root *root = btrfs_block_group_root(gfs_info);
 	struct btrfs_block_group_item bgi;
 	struct btrfs_key key;
 	int ret;
-- 
2.26.3

[PATCH 08/22] btrfs-progs: handle no bg item in extent tree for free space tree

[Josef Bacik]

We have an ASSERT(ret == 0) when populating the free space tree as we
should at least find the block group item with extent tree v1.  However
with v2 we no longer have the block group item in the extent tree, so
fix the population logic to handle an empty block group (which occurs
during mkfs) and only assert if ret != 0 and we don't have extent tree
v2 turned on.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/free-space-tree.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel-shared/free-space-tree.c b/kernel-shared/free-space-tree.c
index 0fdf5004..896bd3a2 100644
--- a/kernel-shared/free-space-tree.c
+++ b/kernel-shared/free-space-tree.c
@@ -1057,6 +1057,9 @@ int populate_free_space_tree(struct btrfs_trans_handle *trans,
 	if (ret)
 		goto out;
 
+	start = block_group->start;
+	end = block_group->start + block_group->length;
+
 	/*
 	 * Iterate through all of the extent and metadata items in this block
 	 * group, adding the free space between them and the free space at the
@@ -1071,10 +1074,11 @@ int populate_free_space_tree(struct btrfs_trans_handle *trans,
 	ret = btrfs_search_slot_for_read(extent_root, &key, path, 1, 0);
 	if (ret < 0)
 		goto out;
-	ASSERT(ret == 0);
+	if (ret > 0) {
+		ASSERT(btrfs_fs_incompat(trans->fs_info, EXTENT_TREE_V2));
+		goto done;
+	}
 
-	start = block_group->start;
-	end = block_group->start + block_group->length;
 	while (1) {
 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 
@@ -1106,6 +1110,7 @@ int populate_free_space_tree(struct btrfs_trans_handle *trans,
 		if (ret)
 			break;
 	}
+done:
 	if (start < end) {
 		ret = __add_to_free_space_tree(trans, block_group, path2,
 				start, end - start);
-- 
2.26.3

[PATCH 09/22] btrfs-progs: mkfs: add support for the block group tree

[Josef Bacik]

Add the extent tree v2 table with the block group tree as a root, and
then create the empty root and use the proper root for cleanup up the
temporary block groups.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/common.c | 93 ++++++++++++++++++++++++++++++++++++++++-----------
 mkfs/common.h | 12 +++++++
 mkfs/main.c   |  5 +++
 3 files changed, 91 insertions(+), 19 deletions(-)

diff --git a/mkfs/common.c b/mkfs/common.c
index ca5393d5..71589c0d 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -39,6 +39,7 @@ static u64 reference_root_table[] = {
 	[MKFS_FS_TREE]		=	BTRFS_FS_TREE_OBJECTID,
 	[MKFS_CSUM_TREE]	=	BTRFS_CSUM_TREE_OBJECTID,
 	[MKFS_FREE_SPACE_TREE]	=	BTRFS_FREE_SPACE_TREE_OBJECTID,
+	[MKFS_BLOCK_GROUP_TREE]	=	BTRFS_BLOCK_GROUP_TREE_OBJECTID,
 };
 
 static int btrfs_write_empty_tree(int fd, struct btrfs_mkfs_config *cfg,
@@ -97,7 +98,8 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
 
 	for (i = 0; i < blocks_nr; i++) {
 		blk = blocks[i];
-		if (blk == MKFS_ROOT_TREE || blk == MKFS_CHUNK_TREE)
+		if (blk == MKFS_ROOT_TREE || blk == MKFS_CHUNK_TREE ||
+		    blk == MKFS_BLOCK_GROUP_TREE)
 			continue;
 
 		btrfs_set_root_bytenr(&root_item, cfg->blocks[blk]);
@@ -188,6 +190,50 @@ static int create_free_space_tree(int fd, struct btrfs_mkfs_config *cfg,
 	return 0;
 }
 
+static void write_block_group_item(struct extent_buffer *buf, u32 nr,
+				   u64 objectid, u64 offset, u64 used,
+				   u32 itemoff)
+{
+	struct btrfs_block_group_item *bg_item;
+	struct btrfs_disk_key disk_key;
+
+	btrfs_set_disk_key_objectid(&disk_key, objectid);
+	btrfs_set_disk_key_offset(&disk_key, offset);
+	btrfs_set_disk_key_type(&disk_key, BTRFS_BLOCK_GROUP_ITEM_KEY);
+	btrfs_set_item_key(buf, &disk_key, nr);
+	btrfs_set_item_offset(buf, btrfs_item_nr(nr), itemoff);
+	btrfs_set_item_size(buf, btrfs_item_nr(nr), sizeof(*bg_item));
+
+	bg_item = btrfs_item_ptr(buf, nr, struct btrfs_block_group_item);
+	btrfs_set_block_group_used(buf, bg_item, used);
+	btrfs_set_block_group_flags(buf, bg_item, BTRFS_BLOCK_GROUP_SYSTEM);
+	btrfs_set_block_group_chunk_objectid(buf, bg_item,
+					     BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+}
+
+static int create_block_group_tree(int fd, struct btrfs_mkfs_config *cfg,
+				   struct extent_buffer *buf,
+				   u64 bg_offset, u64 bg_size, u64 bg_used)
+{
+	int ret;
+
+	memset(buf->data + sizeof(struct btrfs_header), 0,
+		cfg->nodesize - sizeof(struct btrfs_header));
+	write_block_group_item(buf, 0, bg_offset, bg_size, bg_used,
+			       __BTRFS_LEAF_DATA_SIZE(cfg->nodesize) -
+			       sizeof(struct btrfs_block_group_item));
+	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_BLOCK_GROUP_TREE]);
+	btrfs_set_header_owner(buf, BTRFS_BLOCK_GROUP_TREE_OBJECTID);
+	btrfs_set_header_nritems(buf, 1);
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
+			     cfg->csum_type);
+	ret = pwrite(fd, buf->data, cfg->nodesize,
+		     cfg->blocks[MKFS_BLOCK_GROUP_TREE]);
+	if (ret != cfg->nodesize)
+		return ret < 0 ? -errno : -EIO;
+	return 0;
+}
+
 /*
  * @fs_uuid - if NULL, generates a UUID, returns back the new filesystem UUID
  *
@@ -240,11 +286,19 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	bool add_block_group = true;
 	bool free_space_tree = !!(cfg->runtime_features &
 				  BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE);
+	bool extent_tree_v2 = !!(cfg->features &
+				 BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2);
 
 	/* Don't include the free space tree in the blocks to process. */
 	if (!free_space_tree)
 		blocks_nr--;
 
+	if (extent_tree_v2) {
+		blocks = extent_tree_v2_blocks;
+		blocks_nr = ARRAY_SIZE(extent_tree_v2_blocks);
+		add_block_group = false;
+	}
+
 	if ((cfg->features & BTRFS_FEATURE_INCOMPAT_ZONED)) {
 		system_group_offset = cfg->zone_size * BTRFS_NR_SB_LOG_ZONES;
 		system_group_size = cfg->zone_size;
@@ -309,6 +363,12 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 
 		btrfs_set_super_compat_ro_flags(&super, ro_flags);
 	}
+	if (extent_tree_v2) {
+		btrfs_set_super_block_group_root(&super,
+						 cfg->blocks[MKFS_BLOCK_GROUP_TREE]);
+		btrfs_set_super_block_group_root_generation(&super, 1);
+		btrfs_set_super_block_group_root_level(&super, 0);
+	}
 	if (cfg->label)
 		__strncpy_null(super.label, cfg->label, BTRFS_LABEL_SIZE - 1);
 
@@ -340,25 +400,12 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 
 		/* Add the block group item for our temporary chunk. */
 		if (cfg->blocks[blk] > system_group_offset && add_block_group) {
-			struct btrfs_block_group_item *bg_item;
-
+			itemoff -= sizeof(struct btrfs_block_group_item);
+			write_block_group_item(buf, nritems,
+					       system_group_offset,
+					       system_group_size, total_used,
+					       itemoff);
 			add_block_group = false;
-
-			itemoff -= sizeof(*bg_item);
-			btrfs_set_disk_key_objectid(&disk_key, system_group_offset);
-			btrfs_set_disk_key_offset(&disk_key, system_group_size);
-			btrfs_set_disk_key_type(&disk_key, BTRFS_BLOCK_GROUP_ITEM_KEY);
-			btrfs_set_item_key(buf, &disk_key, nritems);
-			btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
-			btrfs_set_item_size(buf, btrfs_item_nr(nritems), sizeof(*bg_item));
-
-			bg_item = btrfs_item_ptr(buf, nritems,
-						 struct btrfs_block_group_item);
-			btrfs_set_block_group_used(buf, bg_item, total_used);
-			btrfs_set_block_group_flags(buf, bg_item,
-						    BTRFS_BLOCK_GROUP_SYSTEM);
-			btrfs_set_block_group_chunk_objectid(buf, bg_item,
-					BTRFS_FIRST_CHUNK_TREE_OBJECTID);
 			nritems++;
 		}
 
@@ -579,6 +626,14 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 			goto out;
 	}
 
+	if (extent_tree_v2) {
+		ret = create_block_group_tree(fd, cfg, buf,
+					      system_group_offset,
+					      system_group_size, total_used);
+		if (ret)
+			goto out;
+	}
+
 	/* and write out the super block */
 	memset(buf->data, 0, BTRFS_SUPER_INFO_SIZE);
 	memcpy(buf->data, &super, sizeof(super));
diff --git a/mkfs/common.h b/mkfs/common.h
index 66c9d9d0..6a48aa52 100644
--- a/mkfs/common.h
+++ b/mkfs/common.h
@@ -51,6 +51,7 @@ enum btrfs_mkfs_block {
 	MKFS_FS_TREE,
 	MKFS_CSUM_TREE,
 	MKFS_FREE_SPACE_TREE,
+	MKFS_BLOCK_GROUP_TREE,
 	MKFS_BLOCK_COUNT
 };
 
@@ -69,6 +70,17 @@ static const enum btrfs_mkfs_block extent_tree_v1_blocks[] = {
 	MKFS_FREE_SPACE_TREE,
 };
 
+static const enum btrfs_mkfs_block extent_tree_v2_blocks[] = {
+	MKFS_ROOT_TREE,
+	MKFS_EXTENT_TREE,
+	MKFS_CHUNK_TREE,
+	MKFS_DEV_TREE,
+	MKFS_FS_TREE,
+	MKFS_CSUM_TREE,
+	MKFS_FREE_SPACE_TREE,
+	MKFS_BLOCK_GROUP_TREE,
+};
+
 struct btrfs_mkfs_config {
 	/* Label of the new filesystem */
 	const char *label;
diff --git a/mkfs/main.c b/mkfs/main.c
index 9a57cef8..1653ab32 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -299,6 +299,11 @@ static int recow_roots(struct btrfs_trans_handle *trans,
 	ret = __recow_root(trans, info->dev_root);
 	if (ret)
 		return ret;
+        if (btrfs_fs_incompat(info, EXTENT_TREE_V2)) {
+		ret = __recow_root(trans, info->block_group_root);
+		if (ret)
+			return ret;
+        }
 	ret = recow_global_roots(trans);
 	if (ret)
 		return ret;
-- 
2.26.3

[PATCH 10/22] btrfs-progs: check: add block group tree support

[Josef Bacik]

This makes the appropriate changes to enable the block group tree
checking for both lowmem and normal check modes.  This is relatively
straightforward, simply need to use the helper to get the right root for
dealing with block groups.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 check/main.c        | 21 ++++++++++++++++++++-
 check/mode-lowmem.c |  4 ++--
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/check/main.c b/check/main.c
index 7735cce1..46d08040 100644
--- a/check/main.c
+++ b/check/main.c
@@ -6229,10 +6229,17 @@ static int check_type_with_root(u64 rootid, u8 key_type)
 		break;
 	case BTRFS_EXTENT_ITEM_KEY:
 	case BTRFS_METADATA_ITEM_KEY:
-	case BTRFS_BLOCK_GROUP_ITEM_KEY:
 		if (rootid != BTRFS_EXTENT_TREE_OBJECTID)
 			goto err;
 		break;
+	case BTRFS_BLOCK_GROUP_ITEM_KEY:
+		if (btrfs_fs_incompat(gfs_info, EXTENT_TREE_V2)) {
+			if (rootid != BTRFS_BLOCK_GROUP_TREE_OBJECTID)
+				goto err;
+		} else if (rootid != BTRFS_EXTENT_TREE_OBJECTID) {
+			goto err;
+		}
+		break;
 	case BTRFS_ROOT_ITEM_KEY:
 		if (rootid != BTRFS_ROOT_TREE_OBJECTID)
 			goto err;
@@ -9453,6 +9460,18 @@ again:
 		return ret;
 	}
 
+	/*
+	 * If we are extent tree v2 then we can reint the block group root as
+	 * well.
+	 */
+	if (btrfs_fs_incompat(gfs_info, EXTENT_TREE_V2)) {
+		ret = btrfs_fsck_reinit_root(trans, gfs_info->block_group_root);
+		if (ret) {
+			fprintf(stderr, "block group initialization failed\n");
+			return ret;
+		}
+	}
+
 	/*
 	 * Now we have all the in-memory block groups setup so we can make
 	 * allocations properly, and the metadata we care about is safe since we
diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
index 263b56d1..7be12e6b 100644
--- a/check/mode-lowmem.c
+++ b/check/mode-lowmem.c
@@ -5530,7 +5530,7 @@ int check_chunks_and_extents_lowmem(void)
 	key.offset = 0;
 	key.type = BTRFS_ROOT_ITEM_KEY;
 
-	ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
+	ret = btrfs_search_slot(NULL, gfs_info->tree_root, &key, &path, 0, 0);
 	if (ret) {
 		error("cannot find extent tree in tree_root");
 		goto out;
@@ -5565,7 +5565,7 @@ int check_chunks_and_extents_lowmem(void)
 		if (ret)
 			goto out;
 next:
-		ret = btrfs_next_item(root, &path);
+		ret = btrfs_next_item(gfs_info->tree_root, &path);
 		if (ret)
 			goto out;
 	}
-- 
2.26.3

[PATCH 11/22] btrfs-progs: qgroup-verify: scan extents based on block groups

[Josef Bacik]

When we switch to per-block group extent roots we'll need to scan each
individual extent root.  To make this easier in the future go ahead and
use the range of the block groups to scan the extents.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 check/qgroup-verify.c | 32 ++++++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/check/qgroup-verify.c b/check/qgroup-verify.c
index 0813b841..45007d8c 100644
--- a/check/qgroup-verify.c
+++ b/check/qgroup-verify.c
@@ -1400,6 +1400,7 @@ static bool is_bad_qgroup(struct qgroup_count *count)
  */
 int qgroup_verify_all(struct btrfs_fs_info *info)
 {
+	struct rb_node *n;
 	int ret;
 	bool found_err = false;
 	bool skip_err = false;
@@ -1430,10 +1431,17 @@ int qgroup_verify_all(struct btrfs_fs_info *info)
 	/*
 	 * Put all extent refs into our rbtree
 	 */
-	ret = scan_extents(info, 0, ~0ULL);
-	if (ret) {
-		fprintf(stderr, "ERROR: while scanning extent tree: %d\n", ret);
-		goto out;
+	for (n = rb_first(&info->block_group_cache_tree); n; n = rb_next(n)) {
+		struct btrfs_block_group *bg;
+
+		bg = rb_entry(n, struct btrfs_block_group, cache_node);
+		ret = scan_extents(info, bg->start,
+				   bg->start + bg->length - 1);
+		if (ret) {
+			fprintf(stderr, "ERROR: while scanning extent tree: %d\n",
+				ret);
+			goto out;
+		}
 	}
 
 	ret = map_implied_refs(info);
@@ -1507,6 +1515,7 @@ static void print_subvol_info(u64 subvolid, u64 bytenr, u64 num_bytes,
 
 int print_extent_state(struct btrfs_fs_info *info, u64 subvol)
 {
+	struct rb_node *n;
 	int ret;
 
 	tree_blocks = ulist_alloc(0);
@@ -1519,10 +1528,17 @@ int print_extent_state(struct btrfs_fs_info *info, u64 subvol)
 	/*
 	 * Put all extent refs into our rbtree
 	 */
-	ret = scan_extents(info, 0, ~0ULL);
-	if (ret) {
-		fprintf(stderr, "ERROR: while scanning extent tree: %d\n", ret);
-		goto out;
+	for (n = rb_first(&info->block_group_cache_tree); n; n = rb_next(n)) {
+		struct btrfs_block_group *bg;
+
+		bg = rb_entry(n, struct btrfs_block_group, cache_node);
+		ret = scan_extents(info, bg->start,
+				   bg->start + bg->length - 1);
+		if (ret) {
+			fprintf(stderr, "ERROR: while scanning extent tree: %d\n",
+				ret);
+			goto out;
+		}
 	}
 
 	ret = map_implied_refs(info);
-- 
2.26.3

[PATCH 12/22] btrfs-progs: check: make free space tree validation extent tree v2 aware

[Josef Bacik]

The free space tree needs to be validated against all referenced blocks
in the file system, so use the btrfs_mark_used_blocks() helper to check
the free space tree and free space cache against.  This will do the
right thing for both extent tree v1 and extent tree v2.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 check/main.c | 90 ++++++++++++++++++----------------------------------
 1 file changed, 31 insertions(+), 59 deletions(-)

diff --git a/check/main.c b/check/main.c
index 46d08040..6252a890 100644
--- a/check/main.c
+++ b/check/main.c
@@ -5611,72 +5611,38 @@ static int check_cache_range(struct btrfs_root *root,
 }
 
 static int verify_space_cache(struct btrfs_root *root,
-			      struct btrfs_block_group *cache)
+			      struct btrfs_block_group *cache,
+			      struct extent_io_tree *used)
 {
-	struct btrfs_path path;
-	struct extent_buffer *leaf;
-	struct btrfs_key key;
-	u64 last;
+	u64 start, end, last_end, bg_end;
 	int ret = 0;
 
-	root = btrfs_extent_root(root->fs_info, cache->start);
+	start = cache->start;
+	bg_end = cache->start + cache->length;
+	last_end = start;
 
-	last = max_t(u64, cache->start, BTRFS_SUPER_INFO_OFFSET);
-
-	btrfs_init_path(&path);
-	key.objectid = last;
-	key.offset = 0;
-	key.type = BTRFS_EXTENT_ITEM_KEY;
-	ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
-	if (ret < 0)
-		goto out;
-	ret = 0;
-	while (1) {
-		if (path.slots[0] >= btrfs_header_nritems(path.nodes[0])) {
-			ret = btrfs_next_leaf(root, &path);
-			if (ret < 0)
-				goto out;
-			if (ret > 0) {
-				ret = 0;
-				break;
-			}
-		}
-		leaf = path.nodes[0];
-		btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
-		if (key.objectid >= cache->start + cache->length)
+	while (start < bg_end) {
+		ret = find_first_extent_bit(used, cache->start, &start, &end,
+					    EXTENT_DIRTY);
+		if (ret || start >= bg_end) {
+			ret = 0;
 			break;
-		if (key.type != BTRFS_EXTENT_ITEM_KEY &&
-		    key.type != BTRFS_METADATA_ITEM_KEY) {
-			path.slots[0]++;
-			continue;
 		}
-
-		if (last == key.objectid) {
-			if (key.type == BTRFS_EXTENT_ITEM_KEY)
-				last = key.objectid + key.offset;
-			else
-				last = key.objectid + gfs_info->nodesize;
-			path.slots[0]++;
-			continue;
+		if (last_end < start) {
+			ret = check_cache_range(root, cache, last_end,
+						start - last_end);
+			if (ret)
+				return ret;
 		}
-
-		ret = check_cache_range(root, cache, last,
-					key.objectid - last);
-		if (ret)
-			break;
-		if (key.type == BTRFS_EXTENT_ITEM_KEY)
-			last = key.objectid + key.offset;
-		else
-			last = key.objectid + gfs_info->nodesize;
-		path.slots[0]++;
+		end = min(end, bg_end - 1);
+		clear_extent_dirty(used, start, end);
+		start = end + 1;
+		last_end = start;
 	}
 
-	if (last < cache->start + cache->length)
-		ret = check_cache_range(root, cache, last,
-					cache->start + cache->length - last);
-
-out:
-	btrfs_release_path(&path);
+	if (last_end < bg_end)
+		ret = check_cache_range(root, cache, last_end,
+					bg_end - last_end);
 
 	if (!ret &&
 	    !RB_EMPTY_ROOT(&cache->free_space_ctl->free_space_offset)) {
@@ -5690,11 +5656,17 @@ out:
 
 static int check_space_cache(struct btrfs_root *root)
 {
+	struct extent_io_tree used;
 	struct btrfs_block_group *cache;
 	u64 start = BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE;
 	int ret;
 	int error = 0;
 
+	extent_io_tree_init(&used);
+	ret = btrfs_mark_used_blocks(gfs_info, &used);
+	if (ret)
+		return ret;
+
 	while (1) {
 		ctx.item_count++;
 		cache = btrfs_lookup_first_block_group(gfs_info, start);
@@ -5739,14 +5711,14 @@ static int check_space_cache(struct btrfs_root *root)
 				continue;
 		}
 
-		ret = verify_space_cache(root, cache);
+		ret = verify_space_cache(root, cache, &used);
 		if (ret) {
 			fprintf(stderr, "cache appears valid but isn't %llu\n",
 				cache->start);
 			error++;
 		}
 	}
-
+	extent_io_tree_cleanup(&used);
 	return error ? -EINVAL : 0;
 }
 
-- 
2.26.3

[PATCH 13/22] btrfs-progs: check: add helper to reinit the root based on a key

[Josef Bacik]

In the case of per-bg roots we may be missing the root items.  To
re-initialize them we want to add the root item as well as allocate the
empty block.  To achieve this extract out the reinit root logic to a
helper that just takes the root key and then does the appropriate work
to allocate an empty root and update the root item.  Fix the normal
reinit root helper to use this new helper.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 check/main.c | 88 ++++++++++++++++++++++++++++++++++------------------
 1 file changed, 58 insertions(+), 30 deletions(-)

diff --git a/check/main.c b/check/main.c
index 6252a890..d2d27694 100644
--- a/check/main.c
+++ b/check/main.c
@@ -9090,29 +9090,34 @@ static int do_check_chunks_and_extents(void)
 	return ret;
 }
 
-static int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans,
-				  struct btrfs_root *root)
+static struct extent_buffer *btrfs_fsck_clear_root(
+					struct btrfs_trans_handle *trans,
+					struct btrfs_key *key)
 {
+	struct btrfs_root_item ri = {};
+	struct btrfs_path *path;
 	struct extent_buffer *c;
-	struct extent_buffer *old = root->node;
-	int level;
+	struct btrfs_disk_key disk_key = {};
 	int ret;
-	struct btrfs_disk_key disk_key = {0,0,0};
 
-	level = 0;
+	path = btrfs_alloc_path();
+	if (!path)
+		return ERR_PTR(-ENOMEM);
 
-	c = btrfs_alloc_free_block(trans, root, gfs_info->nodesize,
-				   root->root_key.objectid,
-				   &disk_key, level, 0, 0);
-	if (IS_ERR(c))
-		return PTR_ERR(c);
+	c = btrfs_alloc_free_block(trans, gfs_info->tree_root,
+				   gfs_info->nodesize, key->objectid,
+				   &disk_key, 0, 0, 0);
+	if (IS_ERR(c)) {
+		btrfs_free_path(path);
+		return c;
+	}
 
 	memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
-	btrfs_set_header_level(c, level);
+	btrfs_set_header_level(c, 0);
 	btrfs_set_header_bytenr(c, c->start);
 	btrfs_set_header_generation(c, trans->transid);
 	btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
-	btrfs_set_header_owner(c, root->root_key.objectid);
+	btrfs_set_header_owner(c, key->objectid);
 
 	write_extent_buffer(c, gfs_info->fs_devices->metadata_uuid,
 			    btrfs_header_fsid(), BTRFS_FSID_SIZE);
@@ -9122,25 +9127,48 @@ static int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans,
 			    BTRFS_UUID_SIZE);
 
 	btrfs_mark_buffer_dirty(c);
+
 	/*
-	 * this case can happen in the following case:
-	 *
-	 * reinit reloc data root, this is because we skip pin
-	 * down reloc data tree before which means we can allocate
-	 * same block bytenr here.
+	 * The root item may not exist, try to insert an empty one so it exists,
+	 * otherwise simply update the existing one with the correct settings.
 	 */
-	if (old->start == c->start) {
-		btrfs_set_root_generation(&root->root_item,
-					  trans->transid);
-		root->root_item.level = btrfs_header_level(root->node);
-		ret = btrfs_update_root(trans, gfs_info->tree_root,
-					&root->root_key, &root->root_item);
-		if (ret) {
-			free_extent_buffer(c);
-			return ret;
-		}
-	}
-	free_extent_buffer(old);
+	ret = btrfs_insert_empty_item(trans, gfs_info->tree_root, path, key,
+				      sizeof(ri));
+	if (ret == -EEXIST) {
+		read_extent_buffer(path->nodes[0], &ri,
+				   btrfs_item_ptr_offset(path->nodes[0],
+							 path->slots[0]),
+				   sizeof(ri));
+	} else if (ret) {
+		btrfs_free_path(path);
+		free_extent_buffer(c);
+		return ERR_PTR(ret);
+	}
+	btrfs_set_root_bytenr(&ri, c->start);
+	btrfs_set_root_generation(&ri, trans->transid);
+	btrfs_set_root_refs(&ri, 1);
+	btrfs_set_root_used(&ri, c->len);
+	btrfs_set_root_generation_v2(&ri, trans->transid);
+
+	write_extent_buffer(path->nodes[0], &ri,
+			    btrfs_item_ptr_offset(path->nodes[0],
+						  path->slots[0]),
+			    sizeof(ri));
+	btrfs_mark_buffer_dirty(path->nodes[0]);
+	btrfs_free_path(path);
+	return c;
+}
+
+static int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans,
+				  struct btrfs_root *root)
+{
+	struct extent_buffer *c;
+
+	c = btrfs_fsck_clear_root(trans, &root->root_key);
+	if (IS_ERR(c))
+		return PTR_ERR(c);
+
+	free_extent_buffer(root->node);
 	root->node = c;
 	add_root_to_dirty_list(root);
 	return 0;
-- 
2.26.3

[PATCH 14/22] btrfs-progs: check: handle the block group tree properly

[Josef Bacik]

We need to make sure we process the block group root, and mark its
blocks as used for the free space tree checking.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 check/main.c    | 27 +++++++++++++++++----------
 common/repair.c |  3 +++
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/check/main.c b/check/main.c
index d2d27694..c28fa2f3 100644
--- a/check/main.c
+++ b/check/main.c
@@ -8908,6 +8908,18 @@ out:
 	return ret;
 }
 
+static int load_super_root(struct list_head *head, struct btrfs_root *root)
+{
+	u8 level;
+
+	if (!root)
+		return 0;
+
+	level = btrfs_header_level(root->node);
+	return add_root_item_to_list(head, root->root_key.objectid,
+				     root->node->start, 0, level, 0, NULL);
+}
+
 static int check_chunks_and_extents(void)
 {
 	struct rb_root dev_cache;
@@ -8926,9 +8938,7 @@ static int check_chunks_and_extents(void)
 	int bits_nr;
 	struct list_head dropping_trees;
 	struct list_head normal_trees;
-	struct btrfs_root *root1;
 	struct btrfs_root *root;
-	u8 level;
 
 	root = gfs_info->fs_root;
 	dev_cache = RB_ROOT;
@@ -8961,16 +8971,13 @@ static int check_chunks_and_extents(void)
 	}
 
 again:
-	root1 = gfs_info->tree_root;
-	level = btrfs_header_level(root1->node);
-	ret = add_root_item_to_list(&normal_trees, root1->root_key.objectid,
-				    root1->node->start, 0, level, 0, NULL);
+	ret = load_super_root(&normal_trees, gfs_info->tree_root);
+	if (ret < 0)
+		goto out;
+	ret = load_super_root(&normal_trees, gfs_info->chunk_root);
 	if (ret < 0)
 		goto out;
-	root1 = gfs_info->chunk_root;
-	level = btrfs_header_level(root1->node);
-	ret = add_root_item_to_list(&normal_trees, root1->root_key.objectid,
-				    root1->node->start, 0, level, 0, NULL);
+	ret = load_super_root(&normal_trees, gfs_info->block_group_root);
 	if (ret < 0)
 		goto out;
 
diff --git a/common/repair.c b/common/repair.c
index 0feaf6c3..3e35ad44 100644
--- a/common/repair.c
+++ b/common/repair.c
@@ -150,6 +150,9 @@ int btrfs_mark_used_tree_blocks(struct btrfs_fs_info *fs_info,
 	if (!ret)
 		ret = traverse_tree_blocks(fs_info, tree,
 					   fs_info->tree_root->node, 1);
+	if (!ret && fs_info->block_group_root)
+		ret = traverse_tree_blocks(fs_info, tree,
+					   fs_info->block_group_root->node, 0);
 	return ret;
 }
 
-- 
2.26.3

[PATCH 15/22] btrfs-progs: load the number of global roots into the fs_info

[Josef Bacik]

We need to know how many global roots we have in order to round robin
assign block groups to their specific global root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/ctree.h   |  2 ++
 kernel-shared/disk-io.c | 42 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
index 27e31e03..c7346fee 100644
--- a/kernel-shared/ctree.h
+++ b/kernel-shared/ctree.h
@@ -1262,6 +1262,8 @@ struct btrfs_fs_info {
 	u32 sectorsize;
 	u32 stripesize;
 
+	u64 num_global_roots;
+
 	/*
 	 * Zone size > 0 when in ZONED mode, otherwise it's used for a check
 	 * if the mode is enabled
diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
index 38741819..4c613b52 100644
--- a/kernel-shared/disk-io.c
+++ b/kernel-shared/disk-io.c
@@ -1432,6 +1432,44 @@ int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
+static int btrfs_get_global_roots_count(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_key key = {
+		.objectid = BTRFS_EXTENT_TREE_OBJECTID,
+		.type = BTRFS_ROOT_ITEM_KEY,
+		.offset = (u64)-1,
+	};
+	struct btrfs_path *path;
+	int ret;
+
+	if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+		return 0;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+	if (ret == 0) {
+		ret = -EINVAL;
+		error("Found a corrupt root item looking for global roots count");
+		goto out;
+	}
+	ret = btrfs_previous_item(fs_info->tree_root, path, key.objectid,
+				  key.type);
+	if (ret) {
+		ret = -EINVAL;
+		error("Didn't find a extent root looking for global roots count");
+		goto out;
+	}
+	btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+	fs_info->num_global_roots = key.offset + 1;
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
 static struct btrfs_fs_info *__open_ctree_fd(int fp, struct open_ctree_flags *ocf)
 {
 	struct btrfs_fs_info *fs_info;
@@ -1578,6 +1616,10 @@ static struct btrfs_fs_info *__open_ctree_fd(int fp, struct open_ctree_flags *oc
 	    !fs_info->ignore_chunk_tree_error)
 		goto out_chunk;
 
+	ret = btrfs_get_global_roots_count(fs_info);
+	if (ret && !(flags & OPEN_CTREE_PARTIAL))
+		goto out_chunk;
+
 	return fs_info;
 
 out_chunk:
-- 
2.26.3

[PATCH 16/22] btrfs-progs: handle the per-block group global root id

[Josef Bacik]

We will now be using block_group->chunk_objectid to point at the global
root id for this particular block group.  For now we'll assign this
based on mod'ing the offset of the block group against the number of
global root id's and handle the block_group_item updating appropriately.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/ctree.h           |  2 ++
 kernel-shared/disk-io.c         | 24 ++++++++++++++++++++++--
 kernel-shared/disk-io.h         |  1 +
 kernel-shared/extent-tree.c     | 17 +++++++++++++++--
 kernel-shared/free-space-tree.c |  3 +++
 5 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
index c7346fee..3914000d 100644
--- a/kernel-shared/ctree.h
+++ b/kernel-shared/ctree.h
@@ -1182,6 +1182,8 @@ struct btrfs_block_group {
 	 */
 	u64 alloc_offset;
 	u64 write_offset;
+
+	u64 global_root_id;
 };
 
 struct btrfs_device;
diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
index 4c613b52..af29a7ae 100644
--- a/kernel-shared/disk-io.c
+++ b/kernel-shared/disk-io.c
@@ -787,13 +787,33 @@ struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
 	return NULL;
 }
 
+u64 btrfs_global_root_id(struct btrfs_fs_info *fs_info, u64 bytenr)
+{
+	struct btrfs_block_group *block_group;
+	u64 ret = 0;
+
+	if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+		return ret;
+
+	/*
+	 * We use this because we won't have this many global roots, and -1 is
+	 * special, so we need something that'll not be found if we have any
+	 * errors from here on.
+	 */
+	ret = BTRFS_LAST_FREE_OBJECTID;
+	block_group = btrfs_lookup_first_block_group(fs_info, bytenr);
+	if (block_group)
+		ret = block_group->global_root_id;
+	return ret;
+}
+
 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info,
 				   u64 bytenr)
 {
 	struct btrfs_key key = {
 		.objectid = BTRFS_CSUM_TREE_OBJECTID,
 		.type = BTRFS_ROOT_ITEM_KEY,
-		.offset = 0,
+		.offset = btrfs_global_root_id(fs_info, bytenr),
 	};
 
 	return btrfs_global_root(fs_info, &key);
@@ -805,7 +825,7 @@ struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info,
 	struct btrfs_key key = {
 		.objectid = BTRFS_EXTENT_TREE_OBJECTID,
 		.type = BTRFS_ROOT_ITEM_KEY,
-		.offset = 0,
+		.offset = btrfs_global_root_id(fs_info, bytenr),
 	};
 
 	return btrfs_global_root(fs_info, &key);
diff --git a/kernel-shared/disk-io.h b/kernel-shared/disk-io.h
index a96a9dfb..e2c2f3d9 100644
--- a/kernel-shared/disk-io.h
+++ b/kernel-shared/disk-io.h
@@ -221,6 +221,7 @@ struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_inf, u64 bytenr);
 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
 				     struct btrfs_key *key);
+u64 btrfs_global_root_id(struct btrfs_fs_info *fs_info, u64 bytenr);
 int btrfs_global_root_insert(struct btrfs_fs_info *fs_info,
 			     struct btrfs_root *root);
 
diff --git a/kernel-shared/extent-tree.c b/kernel-shared/extent-tree.c
index a1c061fa..b282491e 100644
--- a/kernel-shared/extent-tree.c
+++ b/kernel-shared/extent-tree.c
@@ -1561,7 +1561,7 @@ static int update_block_group_item(struct btrfs_trans_handle *trans,
 	btrfs_set_stack_block_group_used(&bgi, cache->used);
 	btrfs_set_stack_block_group_flags(&bgi, cache->flags);
 	btrfs_set_stack_block_group_chunk_objectid(&bgi,
-			BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+						   cache->global_root_id);
 	write_extent_buffer(leaf, &bgi, bi, sizeof(bgi));
 	btrfs_mark_buffer_dirty(leaf);
 fail:
@@ -2658,6 +2658,7 @@ static int read_block_group_item(struct btrfs_block_group *cache,
 			   sizeof(bgi));
 	cache->used = btrfs_stack_block_group_used(&bgi);
 	cache->flags = btrfs_stack_block_group_flags(&bgi);
+	cache->global_root_id = btrfs_stack_block_group_chunk_objectid(&bgi);
 
 	return 0;
 }
@@ -2777,6 +2778,18 @@ btrfs_add_block_group(struct btrfs_fs_info *fs_info, u64 bytes_used, u64 type,
 	cache->start = chunk_offset;
 	cache->length = size;
 
+	/*
+	 * If we have extent tree v2 set then set it to the next global root id
+	 * based on our offset.  Otherwise set it to
+	 * BTRFS_FIRST_CHUNK_TREE_OBJECTID so that extent tree v1 has the
+	 * appropriate setting.
+	 */
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+		cache->global_root_id = div_u64(chunk_offset, SZ_1G) %
+			fs_info->num_global_roots;
+	else
+		cache->global_root_id = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+
 	ret = btrfs_load_block_group_zone_info(fs_info, cache);
 	BUG_ON(ret);
 
@@ -2806,7 +2819,7 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans,
 
 	btrfs_set_stack_block_group_used(&bgi, block_group->used);
 	btrfs_set_stack_block_group_chunk_objectid(&bgi,
-				BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+						   block_group->global_root_id);
 	btrfs_set_stack_block_group_flags(&bgi, block_group->flags);
 	key.objectid = block_group->start;
 	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
diff --git a/kernel-shared/free-space-tree.c b/kernel-shared/free-space-tree.c
index 896bd3a2..a82865d3 100644
--- a/kernel-shared/free-space-tree.c
+++ b/kernel-shared/free-space-tree.c
@@ -34,6 +34,9 @@ static struct btrfs_root *btrfs_free_space_root(struct btrfs_fs_info *fs_info,
 		.offset = 0,
 	};
 
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+		key.offset = block_group->global_root_id;
+
 	return btrfs_global_root(fs_info, &key);
 }
 
-- 
2.26.3

[PATCH 17/22] btrfs-progs: add a btrfs_delete_and_free_root helper

[Josef Bacik]

The free space tree code already does this, but we need it for cleaning
up per block group roots.  Abstract this code out into a helper so that
we can use it in multiple places in the future.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/disk-io.c         | 25 +++++++++++++++++++++++++
 kernel-shared/disk-io.h         |  2 ++
 kernel-shared/free-space-tree.c | 24 +++---------------------
 3 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
index af29a7ae..c35bdff4 100644
--- a/kernel-shared/disk-io.c
+++ b/kernel-shared/disk-io.c
@@ -2349,6 +2349,31 @@ int btrfs_set_buffer_uptodate(struct extent_buffer *eb)
 	return set_extent_buffer_uptodate(eb);
 }
 
+int btrfs_delete_and_free_root(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_root *tree_root = fs_info->tree_root;
+	int ret;
+
+	ret = btrfs_del_root(trans, tree_root, &root->root_key);
+	if (ret)
+		return ret;
+
+	list_del(&root->dirty_list);
+	ret = clean_tree_block(root->node);
+	if (ret)
+		return ret;
+	ret = btrfs_free_tree_block(trans, root, root->node, 0, 1);
+	if (ret)
+		return ret;
+	rb_erase(&root->rb_node, &fs_info->global_roots_tree);
+	free_extent_buffer(root->node);
+	free_extent_buffer(root->commit_root);
+	kfree(root);
+	return 0;
+}
+
 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 				     struct btrfs_fs_info *fs_info,
 				     u64 objectid)
diff --git a/kernel-shared/disk-io.h b/kernel-shared/disk-io.h
index e2c2f3d9..fa4d41f3 100644
--- a/kernel-shared/disk-io.h
+++ b/kernel-shared/disk-io.h
@@ -217,6 +217,8 @@ int btrfs_fs_roots_compare_roots(struct rb_node *node1, struct rb_node *node2);
 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 				     struct btrfs_fs_info *fs_info,
 				     u64 objectid);
+int btrfs_delete_and_free_root(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root);
 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_inf, u64 bytenr);
 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
diff --git a/kernel-shared/free-space-tree.c b/kernel-shared/free-space-tree.c
index a82865d3..0a13b1d6 100644
--- a/kernel-shared/free-space-tree.c
+++ b/kernel-shared/free-space-tree.c
@@ -1257,27 +1257,9 @@ int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info)
 	if (ret)
 		goto abort;
 
-	ret = btrfs_del_root(trans, tree_root, &free_space_root->root_key);
-	if (ret)
-		goto abort;
-
-	list_del(&free_space_root->dirty_list);
-
-	ret = clean_tree_block(free_space_root->node);
-	if (ret)
-		goto abort;
-	ret = btrfs_free_tree_block(trans, free_space_root,
-				    free_space_root->node, 0, 1);
-	if (ret)
-		goto abort;
-
-	rb_erase(&free_space_root->rb_node, &fs_info->global_roots_tree);
-	free_extent_buffer(free_space_root->node);
-	free_extent_buffer(free_space_root->commit_root);
-	kfree(free_space_root);
-
-	ret = btrfs_commit_transaction(trans, tree_root);
-
+	ret = btrfs_delete_and_free_root(trans, free_space_root);
+	if (!ret)
+		ret = btrfs_commit_transaction(trans, tree_root);
 abort:
 	return ret;
 }
-- 
2.26.3

[PATCH 18/22] btrfs-progs: make btrfs_clear_free_space_tree extent tree v2 aware

[Josef Bacik]

With extent tree v2 we'll have multiple free space trees, and we can't
just unset the feature flags for the free space tree.  Fix this to loop
through all of the free space trees and clear them out properly.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/free-space-tree.c | 37 ++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/kernel-shared/free-space-tree.c b/kernel-shared/free-space-tree.c
index 0a13b1d6..70306175 100644
--- a/kernel-shared/free-space-tree.c
+++ b/kernel-shared/free-space-tree.c
@@ -1248,18 +1248,35 @@ int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info)
 	if (IS_ERR(trans))
 		return PTR_ERR(trans);
 
-	features = btrfs_super_compat_ro_flags(fs_info->super_copy);
-	features &= ~(BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID |
-		      BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE);
-	btrfs_set_super_compat_ro_flags(fs_info->super_copy, features);
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		struct btrfs_key key = {
+			.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID,
+			.type = BTRFS_ROOT_ITEM_KEY,
+			.offset = 0,
+		};
+
+		while (key.offset < fs_info->num_global_roots) {
+			free_space_root = btrfs_global_root(fs_info, &key);
+			ret = clear_free_space_tree(trans, free_space_root);
+			if (ret)
+				goto abort;
+			key.offset++;
+		}
+	} else {
+		features = btrfs_super_compat_ro_flags(fs_info->super_copy);
+		features &= ~(BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID |
+			      BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE);
+		btrfs_set_super_compat_ro_flags(fs_info->super_copy, features);
 
-	ret = clear_free_space_tree(trans, free_space_root);
-	if (ret)
-		goto abort;
+		ret = clear_free_space_tree(trans, free_space_root);
+		if (ret)
+			goto abort;
 
-	ret = btrfs_delete_and_free_root(trans, free_space_root);
-	if (!ret)
-		ret = btrfs_commit_transaction(trans, tree_root);
+		ret = btrfs_delete_and_free_root(trans, free_space_root);
+		if (ret)
+			goto abort;
+	}
+	ret = btrfs_commit_transaction(trans, tree_root);
 abort:
 	return ret;
 }
-- 
2.26.3

[PATCH 19/22] btrfs-progs: make btrfs_create_tree take a key for the root key

[Josef Bacik]

We're going to start create global roots from mkfs, and we need to have
a offset set for the root key.  Make the btrfs_create_tree() take a key
for the root_key instead of just the objectid so we can setup these new
style roots properly.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/disk-io.c         | 21 ++++++++-------------
 kernel-shared/disk-io.h         |  2 +-
 kernel-shared/free-space-tree.c |  7 +++++--
 mkfs/main.c                     | 13 ++++++++++---
 4 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
index c35bdff4..b9ee2505 100644
--- a/kernel-shared/disk-io.c
+++ b/kernel-shared/disk-io.c
@@ -2376,25 +2376,22 @@ int btrfs_delete_and_free_root(struct btrfs_trans_handle *trans,
 
 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 				     struct btrfs_fs_info *fs_info,
-				     u64 objectid)
+				     struct btrfs_key *key)
 {
 	struct extent_buffer *leaf;
 	struct btrfs_root *tree_root = fs_info->tree_root;
 	struct btrfs_root *root;
-	struct btrfs_key key;
 	int ret = 0;
 
 	root = kzalloc(sizeof(*root), GFP_KERNEL);
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 
-	btrfs_setup_root(root, fs_info, objectid);
-	root->root_key.objectid = objectid;
-	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
-	root->root_key.offset = 0;
+	btrfs_setup_root(root, fs_info, key->objectid);
+	memcpy(&root->root_key, key, sizeof(struct btrfs_key));
 
-	leaf = btrfs_alloc_free_block(trans, root, fs_info->nodesize, objectid,
-			NULL, 0, 0, 0);
+	leaf = btrfs_alloc_free_block(trans, root, fs_info->nodesize,
+				      root->root_key.objectid, NULL, 0, 0, 0);
 	if (IS_ERR(leaf)) {
 		ret = PTR_ERR(leaf);
 		leaf = NULL;
@@ -2405,7 +2402,7 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 	btrfs_set_header_bytenr(leaf, leaf->start);
 	btrfs_set_header_generation(leaf, trans->transid);
 	btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
-	btrfs_set_header_owner(leaf, objectid);
+	btrfs_set_header_owner(leaf, root->root_key.objectid);
 	root->node = leaf;
 	write_extent_buffer(leaf, fs_info->fs_devices->metadata_uuid,
 			    btrfs_header_fsid(), BTRFS_FSID_SIZE);
@@ -2430,10 +2427,8 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 	memset(root->root_item.uuid, 0, BTRFS_UUID_SIZE);
 	root->root_item.drop_level = 0;
 
-	key.objectid = objectid;
-	key.type = BTRFS_ROOT_ITEM_KEY;
-	key.offset = 0;
-	ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
+	ret = btrfs_insert_root(trans, tree_root, &root->root_key,
+				&root->root_item);
 	if (ret)
 		goto fail;
 
diff --git a/kernel-shared/disk-io.h b/kernel-shared/disk-io.h
index fa4d41f3..9214b56f 100644
--- a/kernel-shared/disk-io.h
+++ b/kernel-shared/disk-io.h
@@ -216,7 +216,7 @@ int write_and_map_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb);
 int btrfs_fs_roots_compare_roots(struct rb_node *node1, struct rb_node *node2);
 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 				     struct btrfs_fs_info *fs_info,
-				     u64 objectid);
+				     struct btrfs_key *key);
 int btrfs_delete_and_free_root(struct btrfs_trans_handle *trans,
 			       struct btrfs_root *root);
 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
diff --git a/kernel-shared/free-space-tree.c b/kernel-shared/free-space-tree.c
index 70306175..23fb67bf 100644
--- a/kernel-shared/free-space-tree.c
+++ b/kernel-shared/free-space-tree.c
@@ -1475,14 +1475,17 @@ int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info)
 	struct btrfs_root *free_space_root;
 	struct btrfs_block_group *block_group;
 	u64 start = BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE;
+	struct btrfs_key root_key = {
+		.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID,
+		.type = BTRFS_ROOT_ITEM_KEY,
+	};
 	int ret;
 
 	trans = btrfs_start_transaction(tree_root, 0);
 	if (IS_ERR(trans))
 		return PTR_ERR(trans);
 
-	free_space_root = btrfs_create_tree(trans, fs_info,
-					    BTRFS_FREE_SPACE_TREE_OBJECTID);
+	free_space_root = btrfs_create_tree(trans, fs_info, &root_key);
 	if (IS_ERR(free_space_root)) {
 		ret = PTR_ERR(free_space_root);
 		goto abort;
diff --git a/mkfs/main.c b/mkfs/main.c
index 1653ab32..fd40c70e 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -717,12 +717,15 @@ static int create_data_reloc_tree(struct btrfs_trans_handle *trans)
 	struct btrfs_inode_item *inode;
 	struct btrfs_root *root;
 	struct btrfs_path path;
-	struct btrfs_key key;
+	struct btrfs_key key = {
+		.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID,
+		.type = BTRFS_ROOT_ITEM_KEY,
+	};
 	u64 ino = BTRFS_FIRST_FREE_OBJECTID;
 	char *name = "..";
 	int ret;
 
-	root = btrfs_create_tree(trans, fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
+	root = btrfs_create_tree(trans, fs_info, &key);
 	if (IS_ERR(root)) {
 		ret = PTR_ERR(root);
 		goto out;
@@ -782,10 +785,14 @@ static int create_uuid_tree(struct btrfs_trans_handle *trans)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_root *root;
+	struct btrfs_key key = {
+		.objectid = BTRFS_UUID_TREE_OBJECTID,
+		.type = BTRFS_ROOT_ITEM_KEY,
+	};
 	int ret = 0;
 
 	ASSERT(fs_info->uuid_root == NULL);
-	root = btrfs_create_tree(trans, fs_info, BTRFS_UUID_TREE_OBJECTID);
+	root = btrfs_create_tree(trans, fs_info, &key);
 	if (IS_ERR(root)) {
 		ret = PTR_ERR(root);
 		goto out;
-- 
2.26.3

[PATCH 20/22] btrfs-progs: mkfs: set chunk_item_objectid properly for extent tree v2

[Josef Bacik]

Our initial block group will use global root id 0 with extent tree v2,
so adjust the helper to take the chunk_objectid as an argument, as we'll
set this to 0 for extent tree v2 and then
BTRFS_FIRST_CHUNK_TREE_OBJECTID for extent tree v1.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/common.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mkfs/common.c b/mkfs/common.c
index 71589c0d..479b1150 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -192,7 +192,7 @@ static int create_free_space_tree(int fd, struct btrfs_mkfs_config *cfg,
 
 static void write_block_group_item(struct extent_buffer *buf, u32 nr,
 				   u64 objectid, u64 offset, u64 used,
-				   u32 itemoff)
+				   u64 chunk_objectid, u32 itemoff)
 {
 	struct btrfs_block_group_item *bg_item;
 	struct btrfs_disk_key disk_key;
@@ -207,8 +207,7 @@ static void write_block_group_item(struct extent_buffer *buf, u32 nr,
 	bg_item = btrfs_item_ptr(buf, nr, struct btrfs_block_group_item);
 	btrfs_set_block_group_used(buf, bg_item, used);
 	btrfs_set_block_group_flags(buf, bg_item, BTRFS_BLOCK_GROUP_SYSTEM);
-	btrfs_set_block_group_chunk_objectid(buf, bg_item,
-					     BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+	btrfs_set_block_group_chunk_objectid(buf, bg_item, chunk_objectid);
 }
 
 static int create_block_group_tree(int fd, struct btrfs_mkfs_config *cfg,
@@ -219,7 +218,7 @@ static int create_block_group_tree(int fd, struct btrfs_mkfs_config *cfg,
 
 	memset(buf->data + sizeof(struct btrfs_header), 0,
 		cfg->nodesize - sizeof(struct btrfs_header));
-	write_block_group_item(buf, 0, bg_offset, bg_size, bg_used,
+	write_block_group_item(buf, 0, bg_offset, bg_size, bg_used, 0,
 			       __BTRFS_LEAF_DATA_SIZE(cfg->nodesize) -
 			       sizeof(struct btrfs_block_group_item));
 	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_BLOCK_GROUP_TREE]);
@@ -404,6 +403,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 			write_block_group_item(buf, nritems,
 					       system_group_offset,
 					       system_group_size, total_used,
+					       BTRFS_FIRST_CHUNK_TREE_OBJECTID,
 					       itemoff);
 			add_block_group = false;
 			nritems++;
-- 
2.26.3

[PATCH 21/22] btrfs-progs: mkfs: create the global root's

[Josef Bacik]

Now that we have all of the supporting code, add the ability to create
all of the global roots for an extent tree v2 fs.  This will default to
nr_cpu's, but also allow the user to specify how many global roots they
would like.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/main.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 67 insertions(+), 1 deletion(-)

diff --git a/mkfs/main.c b/mkfs/main.c
index fd40c70e..8959fd8b 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -810,6 +810,50 @@ out:
 	return ret;
 }
 
+static int create_global_root(struct btrfs_trans_handle *trans, u64 objectid,
+			      int root_id)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_root *root;
+	struct btrfs_key key = {
+		.objectid = objectid,
+		.type = BTRFS_ROOT_ITEM_KEY,
+		.offset = root_id,
+	};
+	int ret = 0;
+
+	root = btrfs_create_tree(trans, fs_info, &key);
+	if (IS_ERR(root)) {
+		ret = PTR_ERR(root);
+		goto out;
+	}
+	ret = btrfs_global_root_insert(fs_info, root);
+out:
+	if (ret)
+		btrfs_abort_transaction(trans, ret);
+	return ret;
+}
+
+static int create_global_roots(struct btrfs_trans_handle *trans,
+			       int nr_global_roots)
+{
+	int ret, i;
+
+	for (i = 1; i < nr_global_roots; i++) {
+		ret = create_global_root(trans, BTRFS_EXTENT_TREE_OBJECTID, i);
+		if (ret)
+			return ret;
+		ret = create_global_root(trans, BTRFS_CSUM_TREE_OBJECTID, i);
+		if (ret)
+			return ret;
+		ret = create_global_root(trans, BTRFS_FREE_SPACE_TREE_OBJECTID, i);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static int insert_qgroup_items(struct btrfs_trans_handle *trans,
 			       struct btrfs_fs_info *fs_info,
 			       u64 qgroupid)
@@ -966,13 +1010,18 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
 	struct btrfs_mkfs_config mkfs_cfg;
 	enum btrfs_csum_type csum_type = BTRFS_CSUM_TYPE_CRC32;
 	u64 system_group_size;
+	int nr_global_roots = sysconf(_SC_NPROCESSORS_ONLN);
 
 	crc32c_optimization_init();
 	btrfs_config_init();
 
 	while(1) {
 		int c;
-		enum { GETOPT_VAL_SHRINK = 257, GETOPT_VAL_CHECKSUM };
+		enum {
+			GETOPT_VAL_SHRINK = 257,
+			GETOPT_VAL_CHECKSUM,
+			GETOPT_VAL_GLOBAL_ROOTS,
+		};
 		static const struct option long_options[] = {
 			{ "byte-count", required_argument, NULL, 'b' },
 			{ "csum", required_argument, NULL,
@@ -996,6 +1045,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
 			{ "quiet", 0, NULL, 'q' },
 			{ "verbose", 0, NULL, 'v' },
 			{ "shrink", no_argument, NULL, GETOPT_VAL_SHRINK },
+			{ "num-global-roots", required_argument, NULL, GETOPT_VAL_GLOBAL_ROOTS },
 			{ "help", no_argument, NULL, GETOPT_VAL_HELP },
 			{ NULL, 0, NULL, 0}
 		};
@@ -1100,6 +1150,9 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
 			case GETOPT_VAL_CHECKSUM:
 				csum_type = parse_csum_type(optarg);
 				break;
+			case GETOPT_VAL_GLOBAL_ROOTS:
+				nr_global_roots = (int)arg_strtou64(optarg);
+				break;
 			case GETOPT_VAL_HELP:
 			default:
 				print_usage(c != GETOPT_VAL_HELP);
@@ -1239,6 +1292,11 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
 	if (features & BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2) {
 		features |= BTRFS_FEATURE_INCOMPAT_NO_HOLES;
 		runtime_features |= BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE;
+
+		if (!nr_global_roots) {
+			error("you must set a non-zero num-global-roots value");
+			exit(1);
+		}
 	}
 
 	if (zoned) {
@@ -1466,6 +1524,14 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
 		goto error;
 	}
 
+	if (features & BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2) {
+		ret = create_global_roots(trans, nr_global_roots);
+		if (ret) {
+			error("failed to create global roots: %d", ret);
+			goto error;
+		}
+	}
+
 	ret = make_root_dir(trans, root);
 	if (ret) {
 		error("failed to setup the root directory: %d", ret);
-- 
2.26.3

[PATCH 22/22] btrfs-progs: check: don't do the root item check for extent tree v2

[Josef Bacik]

With the current set of changes we could probably do this check, but it
would involve changing the code quite a bit, and in the future we're not
going to track the metadata in the extent tree at all.  Since this check
was for a very old kernel just skip it for extent tree v2.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 check/main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/check/main.c b/check/main.c
index c28fa2f3..0bd87685 100644
--- a/check/main.c
+++ b/check/main.c
@@ -10065,6 +10065,9 @@ static int repair_root_items(void)
 	int bad_roots = 0;
 	int need_trans = 0;
 
+	if (btrfs_fs_incompat(gfs_info, EXTENT_TREE_V2))
+		return 0;
+
 	btrfs_init_path(&path);
 
 	ret = build_roots_info_cache();
-- 
2.26.3

Re: [PATCH 04/22] btrfs-progs: add support for loading the block group root

[David Sterba]

On Fri, Nov 05, 2021 at 04:40:30PM -0400, Josef Bacik wrote:
> This adds the ability to load the block group root, as well as make sure
> the various backup super block and super block updates are made
> appropriately.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
>  kernel-shared/ctree.h       |   1 +
>  kernel-shared/disk-io.c     | 156 +++++++++++++++++++++++++++---------
>  kernel-shared/disk-io.h     |  10 ++-
>  kernel-shared/extent-tree.c |   8 +-
>  kernel-shared/transaction.c |   2 +
>  5 files changed, 135 insertions(+), 42 deletions(-)
> 
> diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
> index e54e03c4..27e31e03 100644
> --- a/kernel-shared/ctree.h
> +++ b/kernel-shared/ctree.h
> @@ -1195,6 +1195,7 @@ struct btrfs_fs_info {
>  	struct btrfs_root *dev_root;
>  	struct btrfs_root *quota_root;
>  	struct btrfs_root *uuid_root;
> +	struct btrfs_root *block_group_root;
>  
>  	struct rb_root global_roots_tree;
>  	struct rb_root fs_root_tree;
> diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
> index bea42556..38741819 100644
> --- a/kernel-shared/disk-io.c
> +++ b/kernel-shared/disk-io.c
> @@ -838,6 +838,9 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
>  		root = btrfs_global_root(fs_info, location);
>  		return root ? root : ERR_PTR(-ENOENT);
>  	}
> +	if (location->objectid == BTRFS_BLOCK_GROUP_TREE_OBJECTID)
> +		return fs_info->block_group_root ? fs_info->block_group_root :
> +						ERR_PTR(-ENOENT);
>  
>  	BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID);
>  
> @@ -876,6 +879,7 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
>  	free(fs_info->chunk_root);
>  	free(fs_info->dev_root);
>  	free(fs_info->uuid_root);
> +	free(fs_info->block_group_root);
>  	free(fs_info->super_copy);
>  	free(fs_info->log_root_tree);
>  	free(fs_info);
> @@ -894,10 +898,12 @@ struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
>  	fs_info->dev_root = calloc(1, sizeof(struct btrfs_root));
>  	fs_info->quota_root = calloc(1, sizeof(struct btrfs_root));
>  	fs_info->uuid_root = calloc(1, sizeof(struct btrfs_root));
> +	fs_info->block_group_root = calloc(1, sizeof(struct btrfs_root));
>  	fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
>  
>  	if (!fs_info->tree_root || !fs_info->chunk_root || !fs_info->dev_root ||
> -	    !fs_info->quota_root || !fs_info->uuid_root || !fs_info->super_copy)
> +	    !fs_info->quota_root || !fs_info->uuid_root ||
> +	    !fs_info->block_group_root || !fs_info->super_copy)
>  		goto free_all;
>  
>  	extent_io_tree_init(&fs_info->extent_cache);
> @@ -1016,7 +1022,7 @@ static int read_root_or_create_block(struct btrfs_fs_info *fs_info,
>  static inline bool maybe_load_block_groups(struct btrfs_fs_info *fs_info,
>  					   u64 flags)
>  {
> -	struct btrfs_root *root = btrfs_extent_root(fs_info, 0);
> +	struct btrfs_root *root = btrfs_block_group_root(fs_info);
>  
>  	if (flags & OPEN_CTREE_NO_BLOCK_GROUPS)
>  		return false;
> @@ -1027,7 +1033,6 @@ static inline bool maybe_load_block_groups(struct btrfs_fs_info *fs_info,
>  	return false;
>  }
>  
> -
>  static int load_global_roots_objectid(struct btrfs_fs_info *fs_info,
>  				      struct btrfs_path *path, u64 objectid,
>  				      unsigned flags, char *str)
> @@ -1125,39 +1130,94 @@ out:
>  	return ret;
>  }
>  
> -int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
> -			  unsigned flags)
> +static int load_important_roots(struct btrfs_fs_info *fs_info,
> +				u64 root_tree_bytenr, unsigned flags)
>  {
>  	struct btrfs_super_block *sb = fs_info->super_copy;
> +	struct btrfs_root_backup *backup = NULL;
>  	struct btrfs_root *root;
> -	struct btrfs_key key;
> -	u64 generation;
> +	u64 bytenr, gen;
> +	int index = -1;
>  	int ret;
>  
> -	root = fs_info->tree_root;
> -	btrfs_setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
> -	generation = btrfs_super_generation(sb);

I've got a conflict when applying this, there's a level for the root
also read and passed to read_root_node, while this patch does not expect
it. I think I haven't missed any patch that would drop the parameter,
all the preparatory v2 patches are in devel. Can you please refresh 4-22
and resend? Thanks.