[PATCH v2 00/10] btrfs-progs: mkfs fixes and prep work for extent tree v2

[PATCH v2 00/10] btrfs-progs: mkfs fixes and prep work for extent tree v2

[Josef Bacik]

v1->v2:
- Rebase onto devel+block group used patches.
- Dropped MKFS_SUPER_BLOCK as suggested by Qu.
- Make sure to recow the free space root now that we're generating it at
  make_btrfs() time.
- Rewored the titles to include the target area.
- Dropped "btrfs-progs: allocate blocks from the start of the temp system chunk"
  as it is no longer needed with the MKFS_SUPER_BLOCK dropping.
- Add a patch to make sure ->ref_cows and ->track_dirty is set properly on roots
  if we read roots directly.

--- Original email ---
Hello,

In order to reduce the amount of pain the reviewers have to endure I'm going to
be sending any prepatory patches separately from the actual feature work.

To that end this is the first batch of preparatory patches.  These are to make
working with mkfs a lot easier for the changes I'm making.  These are all fixes
or enhancements that can apply currently.  The only thing that is extent tree v2
specific is the last patch, which adds the incompat flag.

I've added the patch for the incompat flag because I will have other preparatory
patches that add helpers that essentially do

if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
	/* Do the old thing. */

and then have patches after that add the extent tree v2 magic.  I think this
will make it easier to break up the work, but if we're not comfortable reserving
the bit then I'm fine with dropping that last patch.  It will just mean future
prep work will have to come along with the feature enablement patches.

I've tested this with make test to validate I didn't break anything.  Thanks,

Josef

Josef Bacik (10):
  btrfs-progs: mkfs: use an associative array for init blocks
  btrfs-progs: mkfs: get rid of MKFS_SUPER_BLOCK
  btrfs-progs: mkfs: use blocks_nr to determine the super used bytes
  btrfs-progs: mkfs: set nritems based on root items written
  btrfs-progs: mkfs: add helper for writing empty tree nodes
  btrfs-progs: make sure track_dirty and ref_cows is set properly
  btrfs-progs: mkfs: add the block group item in make_btrfs()
  btrfs-progs: add add_block_group_free_space helper
  btrfs-progs: mkfs: generate free space tree at make_btrfs() time
  btrfs-progs: add the incompat flag for extent tree v2

 kernel-shared/ctree.h           |   1 +
 kernel-shared/disk-io.c         |   5 +-
 kernel-shared/extent-tree.c     |   2 +
 kernel-shared/free-space-tree.c |  26 ++++
 kernel-shared/free-space-tree.h |   2 +
 mkfs/common.c                   | 212 ++++++++++++++++++++++++--------
 mkfs/common.h                   |  19 ++-
 mkfs/main.c                     |  24 ++--
 8 files changed, 224 insertions(+), 67 deletions(-)

-- 
2.26.3

[PATCH v2 01/10] btrfs-progs: mkfs: use an associative array for init blocks

[Josef Bacik]

Extent tree v2 will not create an extent tree or csum tree initially,
and it will create a block group tree.  To handle this we want to rework
the initial mkfs step to take an array of the blocks we want to create
and use the array to keep track of which blocks we need to create.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/common.c | 53 ++++++++++++++++++++++++++++++++-------------------
 mkfs/common.h | 10 ++++++++++
 2 files changed, 43 insertions(+), 20 deletions(-)

diff --git a/mkfs/common.c b/mkfs/common.c
index 2c041224..35ee4bff 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -31,16 +31,18 @@
 #include "mkfs/common.h"
 
 static u64 reference_root_table[] = {
-	[1] =	BTRFS_ROOT_TREE_OBJECTID,
-	[2] =	BTRFS_EXTENT_TREE_OBJECTID,
-	[3] =	BTRFS_CHUNK_TREE_OBJECTID,
-	[4] =	BTRFS_DEV_TREE_OBJECTID,
-	[5] =	BTRFS_FS_TREE_OBJECTID,
-	[6] =	BTRFS_CSUM_TREE_OBJECTID,
+	[MKFS_ROOT_TREE]	=	BTRFS_ROOT_TREE_OBJECTID,
+	[MKFS_EXTENT_TREE]	=	BTRFS_EXTENT_TREE_OBJECTID,
+	[MKFS_CHUNK_TREE]	=	BTRFS_CHUNK_TREE_OBJECTID,
+	[MKFS_DEV_TREE]		=	BTRFS_DEV_TREE_OBJECTID,
+	[MKFS_FS_TREE]		=	BTRFS_FS_TREE_OBJECTID,
+	[MKFS_CSUM_TREE]	=	BTRFS_CSUM_TREE_OBJECTID,
 };
 
 static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
-			struct extent_buffer *buf)
+				  struct extent_buffer *buf,
+				  const enum btrfs_mkfs_block *blocks,
+				  int blocks_nr)
 {
 	struct btrfs_root_item root_item;
 	struct btrfs_inode_item *inode_item;
@@ -49,6 +51,7 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
 	u32 itemoff;
 	int ret = 0;
 	int blk;
+	int i;
 	u8 uuid[BTRFS_UUID_SIZE];
 
 	memset(buf->data + sizeof(struct btrfs_header), 0,
@@ -71,7 +74,8 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
 	btrfs_set_disk_key_offset(&disk_key, 0);
 	itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize) - sizeof(root_item);
 
-	for (blk = 0; blk < MKFS_BLOCK_COUNT; blk++) {
+	for (i = 0; i < blocks_nr; i++) {
+		blk = blocks[i];
 		if (blk == MKFS_SUPER_BLOCK || blk == MKFS_ROOT_TREE
 		    || blk == MKFS_CHUNK_TREE)
 			continue;
@@ -145,10 +149,13 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	struct btrfs_chunk *chunk;
 	struct btrfs_dev_item *dev_item;
 	struct btrfs_dev_extent *dev_extent;
+	const enum btrfs_mkfs_block *blocks = extent_tree_v1_blocks;
 	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
 	u8 *ptr;
 	int i;
 	int ret;
+	int blocks_nr = ARRAY_SIZE(extent_tree_v1_blocks);
+	int blk;
 	u32 itemoff;
 	u32 nritems = 0;
 	u64 first_free;
@@ -195,7 +202,10 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	uuid_generate(chunk_tree_uuid);
 
 	cfg->blocks[MKFS_SUPER_BLOCK] = BTRFS_SUPER_INFO_OFFSET;
-	for (i = 1; i < MKFS_BLOCK_COUNT; i++) {
+	for (i = 0; i < blocks_nr; i++) {
+		blk = blocks[i];
+		if (blk == MKFS_SUPER_BLOCK)
+			continue;
 		cfg->blocks[i] = system_group_offset + cfg->nodesize * (i - 1);
 	}
 
@@ -236,7 +246,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 			    btrfs_header_chunk_tree_uuid(buf),
 			    BTRFS_UUID_SIZE);
 
-	ret = btrfs_create_tree_root(fd, cfg, buf);
+	ret = btrfs_create_tree_root(fd, cfg, buf, blocks, blocks_nr);
 	if (ret < 0)
 		goto out;
 
@@ -245,30 +255,33 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 		cfg->nodesize - sizeof(struct btrfs_header));
 	nritems = 0;
 	itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
-	for (i = 1; i < MKFS_BLOCK_COUNT; i++) {
+	for (i = 0; i < blocks_nr; i++) {
+		blk = blocks[i];
+		if (blk == MKFS_SUPER_BLOCK)
+			continue;
 		item_size = sizeof(struct btrfs_extent_item);
 		if (!skinny_metadata)
 			item_size += sizeof(struct btrfs_tree_block_info);
 
-		if (cfg->blocks[i] < first_free) {
+		if (cfg->blocks[blk] < first_free) {
 			error("block[%d] below first free: %llu < %llu",
-					i, (unsigned long long)cfg->blocks[i],
+					i, (unsigned long long)cfg->blocks[blk],
 					(unsigned long long)first_free);
 			ret = -EINVAL;
 			goto out;
 		}
-		if (cfg->blocks[i] < cfg->blocks[i - 1]) {
+		if (cfg->blocks[blk] < cfg->blocks[blocks[i - 1]]) {
 			error("blocks %d and %d in reverse order: %llu < %llu",
-				i, i - 1,
-				(unsigned long long)cfg->blocks[i],
-				(unsigned long long)cfg->blocks[i - 1]);
+				blk, blocks[i - 1],
+				(unsigned long long)cfg->blocks[blk],
+				(unsigned long long)cfg->blocks[blocks[i - 1]]);
 			ret = -EINVAL;
 			goto out;
 		}
 
 		/* create extent item */
 		itemoff -= item_size;
-		btrfs_set_disk_key_objectid(&disk_key, cfg->blocks[i]);
+		btrfs_set_disk_key_objectid(&disk_key, cfg->blocks[blk]);
 		if (skinny_metadata) {
 			btrfs_set_disk_key_type(&disk_key,
 						BTRFS_METADATA_ITEM_KEY);
@@ -292,8 +305,8 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 		nritems++;
 
 		/* create extent ref */
-		ref_root = reference_root_table[i];
-		btrfs_set_disk_key_objectid(&disk_key, cfg->blocks[i]);
+		ref_root = reference_root_table[blk];
+		btrfs_set_disk_key_objectid(&disk_key, cfg->blocks[blk]);
 		btrfs_set_disk_key_offset(&disk_key, ref_root);
 		btrfs_set_disk_key_type(&disk_key, BTRFS_TREE_BLOCK_REF_KEY);
 		btrfs_set_item_key(buf, &disk_key, nritems);
diff --git a/mkfs/common.h b/mkfs/common.h
index ea87c3ca..378da6bd 100644
--- a/mkfs/common.h
+++ b/mkfs/common.h
@@ -55,6 +55,16 @@ enum btrfs_mkfs_block {
 	MKFS_BLOCK_COUNT
 };
 
+static const enum btrfs_mkfs_block extent_tree_v1_blocks[] = {
+	MKFS_SUPER_BLOCK,
+	MKFS_ROOT_TREE,
+	MKFS_EXTENT_TREE,
+	MKFS_CHUNK_TREE,
+	MKFS_DEV_TREE,
+	MKFS_FS_TREE,
+	MKFS_CSUM_TREE,
+};
+
 struct btrfs_mkfs_config {
 	/* Label of the new filesystem */
 	const char *label;
-- 
2.26.3

[PATCH v2 02/10] btrfs-progs: mkfs: get rid of MKFS_SUPER_BLOCK

[Josef Bacik]

We use these block's in order to keep track of which blocks need to be
added to the extent tree and where their roots need to be written.
However we skip MKFS_SUPER_BLOCK for all of these helpers, and we don't
actually need to keep track of the specific block we allocated because
it is always BTRFS_SUPER_INFO_OFFSET.  Remove this enum as we don't need
it.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/common.c | 17 ++++++-----------
 mkfs/common.h |  2 --
 2 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/mkfs/common.c b/mkfs/common.c
index 35ee4bff..ee9ad390 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -76,8 +76,7 @@ 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_SUPER_BLOCK || blk == MKFS_ROOT_TREE
-		    || blk == MKFS_CHUNK_TREE)
+		if (blk == MKFS_ROOT_TREE || blk == MKFS_CHUNK_TREE)
 			continue;
 
 		btrfs_set_root_bytenr(&root_item, cfg->blocks[blk]);
@@ -201,15 +200,12 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	uuid_generate(super.dev_item.uuid);
 	uuid_generate(chunk_tree_uuid);
 
-	cfg->blocks[MKFS_SUPER_BLOCK] = BTRFS_SUPER_INFO_OFFSET;
 	for (i = 0; i < blocks_nr; i++) {
 		blk = blocks[i];
-		if (blk == MKFS_SUPER_BLOCK)
-			continue;
-		cfg->blocks[i] = system_group_offset + cfg->nodesize * (i - 1);
+		cfg->blocks[blk] = system_group_offset + cfg->nodesize * i;
 	}
 
-	btrfs_set_super_bytenr(&super, cfg->blocks[MKFS_SUPER_BLOCK]);
+	btrfs_set_super_bytenr(&super, BTRFS_SUPER_INFO_OFFSET);
 	btrfs_set_super_num_devices(&super, 1);
 	btrfs_set_super_magic(&super, BTRFS_MAGIC_TEMPORARY);
 	btrfs_set_super_generation(&super, 1);
@@ -257,8 +253,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
 	for (i = 0; i < blocks_nr; i++) {
 		blk = blocks[i];
-		if (blk == MKFS_SUPER_BLOCK)
-			continue;
+
 		item_size = sizeof(struct btrfs_extent_item);
 		if (!skinny_metadata)
 			item_size += sizeof(struct btrfs_tree_block_info);
@@ -270,7 +265,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 			ret = -EINVAL;
 			goto out;
 		}
-		if (cfg->blocks[blk] < cfg->blocks[blocks[i - 1]]) {
+		if (i && cfg->blocks[blk] < cfg->blocks[blocks[i - 1]]) {
 			error("blocks %d and %d in reverse order: %llu < %llu",
 				blk, blocks[i - 1],
 				(unsigned long long)cfg->blocks[blk],
@@ -487,7 +482,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	buf->len = BTRFS_SUPER_INFO_SIZE;
 	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
-	ret = sbwrite(fd, buf->data, cfg->blocks[MKFS_SUPER_BLOCK]);
+	ret = sbwrite(fd, buf->data, BTRFS_SUPER_INFO_OFFSET);
 	if (ret != BTRFS_SUPER_INFO_SIZE) {
 		ret = (ret < 0 ? -errno : -EIO);
 		goto out;
diff --git a/mkfs/common.h b/mkfs/common.h
index 378da6bd..f2d28057 100644
--- a/mkfs/common.h
+++ b/mkfs/common.h
@@ -45,7 +45,6 @@ struct btrfs_root;
  * Tree root blocks created during mkfs
  */
 enum btrfs_mkfs_block {
-	MKFS_SUPER_BLOCK = 0,
 	MKFS_ROOT_TREE,
 	MKFS_EXTENT_TREE,
 	MKFS_CHUNK_TREE,
@@ -56,7 +55,6 @@ enum btrfs_mkfs_block {
 };
 
 static const enum btrfs_mkfs_block extent_tree_v1_blocks[] = {
-	MKFS_SUPER_BLOCK,
 	MKFS_ROOT_TREE,
 	MKFS_EXTENT_TREE,
 	MKFS_CHUNK_TREE,
-- 
2.26.3

[PATCH v2 03/10] btrfs-progs: mkfs: use blocks_nr to determine the super used bytes

[Josef Bacik]

We were setting the superblock's used bytes to a static number.  However
the number of blocks we have to write has the correct used size, so just
add up the total number of blocks we're allocating as we determine their
offsets.  This value will be used later which is why I'm calculating it
this way instead of doing the math to set the bytes_super specifically.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/common.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mkfs/common.c b/mkfs/common.c
index ee9ad390..8718969d 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -161,6 +161,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	u64 ref_root;
 	u32 array_size;
 	u32 item_size;
+	u64 total_used = 0;
 	int skinny_metadata = !!(cfg->features &
 				 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
 	u64 num_bytes;
@@ -203,6 +204,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	for (i = 0; i < blocks_nr; i++) {
 		blk = blocks[i];
 		cfg->blocks[blk] = system_group_offset + cfg->nodesize * i;
+		total_used += cfg->nodesize;
 	}
 
 	btrfs_set_super_bytenr(&super, BTRFS_SUPER_INFO_OFFSET);
@@ -212,7 +214,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	btrfs_set_super_root(&super, cfg->blocks[MKFS_ROOT_TREE]);
 	btrfs_set_super_chunk_root(&super, cfg->blocks[MKFS_CHUNK_TREE]);
 	btrfs_set_super_total_bytes(&super, num_bytes);
-	btrfs_set_super_bytes_used(&super, 6 * cfg->nodesize);
+	btrfs_set_super_bytes_used(&super, total_used);
 	btrfs_set_super_sectorsize(&super, cfg->sectorsize);
 	super.__unused_leafsize = cpu_to_le32(cfg->nodesize);
 	btrfs_set_super_nodesize(&super, cfg->nodesize);
-- 
2.26.3

[PATCH v2 04/10] btrfs-progs: mkfs: set nritems based on root items written

[Josef Bacik]

For the root tree we were just hard setting the nritems to 4, which will
change when we move to extent tree v2.  Instead set the nritems after
we've added all the root items we need to the root tree.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/common.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mkfs/common.c b/mkfs/common.c
index 8718969d..339c5556 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -106,6 +106,8 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
 		itemoff -= sizeof(root_item);
 	}
 
+	btrfs_set_header_nritems(buf, nritems);
+
 	/* generate checksum */
 	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
 			     cfg->csum_type);
@@ -233,7 +235,6 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	memset(buf->data, 0, cfg->nodesize);
 	buf->len = cfg->nodesize;
 	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_ROOT_TREE]);
-	btrfs_set_header_nritems(buf, 4);
 	btrfs_set_header_generation(buf, 1);
 	btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
 	btrfs_set_header_owner(buf, BTRFS_ROOT_TREE_OBJECTID);
-- 
2.26.3

[PATCH v2 05/10] btrfs-progs: mkfs: add helper for writing empty tree nodes

[Josef Bacik]

With extent tree v2 we're going to be writing some more empty trees for
the initial mkfs step, so take this common code and make it a helper.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/common.c | 47 +++++++++++++++++++++++++----------------------
 1 file changed, 25 insertions(+), 22 deletions(-)

diff --git a/mkfs/common.c b/mkfs/common.c
index 339c5556..a392a5b0 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -39,6 +39,25 @@ static u64 reference_root_table[] = {
 	[MKFS_CSUM_TREE]	=	BTRFS_CSUM_TREE_OBJECTID,
 };
 
+static int btrfs_write_empty_tree(int fd, struct btrfs_mkfs_config *cfg,
+				  struct extent_buffer *buf, u64 objectid,
+				  u64 block)
+{
+	int ret;
+
+	memset(buf->data + sizeof(struct btrfs_header), 0,
+		cfg->nodesize - sizeof(struct btrfs_header));
+	btrfs_set_header_bytenr(buf, block);
+	btrfs_set_header_owner(buf, objectid);
+	btrfs_set_header_nritems(buf, 0);
+	csum_tree_block_size(buf, btrfs_csum_type_size(cfg->csum_type), 0,
+			     cfg->csum_type);
+	ret = pwrite(fd, buf->data, cfg->nodesize, block);
+	if (ret != cfg->nodesize)
+		return ret < 0 ? -errno : -EIO;
+	return 0;
+}
+
 static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
 				  struct extent_buffer *buf,
 				  const enum btrfs_mkfs_block *blocks,
@@ -453,31 +472,15 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	}
 
 	/* create the FS root */
-	memset(buf->data + sizeof(struct btrfs_header), 0,
-		cfg->nodesize - sizeof(struct btrfs_header));
-	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_FS_TREE]);
-	btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);
-	btrfs_set_header_nritems(buf, 0);
-	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_FS_TREE]);
-	if (ret != cfg->nodesize) {
-		ret = (ret < 0 ? -errno : -EIO);
+	ret = btrfs_write_empty_tree(fd, cfg, buf, BTRFS_FS_TREE_OBJECTID,
+				     cfg->blocks[MKFS_FS_TREE]);
+	if (ret)
 		goto out;
-	}
 	/* finally create the csum root */
-	memset(buf->data + sizeof(struct btrfs_header), 0,
-		cfg->nodesize - sizeof(struct btrfs_header));
-	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_CSUM_TREE]);
-	btrfs_set_header_owner(buf, BTRFS_CSUM_TREE_OBJECTID);
-	btrfs_set_header_nritems(buf, 0);
-	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_CSUM_TREE]);
-	if (ret != cfg->nodesize) {
-		ret = (ret < 0 ? -errno : -EIO);
+	ret = btrfs_write_empty_tree(fd, cfg, buf, BTRFS_CSUM_TREE_OBJECTID,
+				     cfg->blocks[MKFS_CSUM_TREE]);
+	if (ret)
 		goto out;
-	}
 
 	/* and write out the super block */
 	memset(buf->data, 0, BTRFS_SUPER_INFO_SIZE);
-- 
2.26.3

[PATCH v2 06/10] btrfs-progs: make sure track_dirty and ref_cows is set properly

[Josef Bacik]

Adding support for the per-block group roots means we will be reading
the roots directly in different places.  Make sure we set ->track_dirty
and ->ref_cows properly in the helper so we don't have to do this
everywhere.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/disk-io.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
index 84990a52..7f99fc8d 100644
--- a/kernel-shared/disk-io.c
+++ b/kernel-shared/disk-io.c
@@ -720,7 +720,10 @@ out:
 		return ERR_PTR(-EIO);
 	}
 insert:
-	root->ref_cows = 1;
+	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+		root->track_dirty = 1;
+	if (is_fstree(root->root_key.objectid))
+		root->ref_cows = 1;
 	return root;
 }
 
-- 
2.26.3

[PATCH v2 07/10] btrfs-progs: mkfs: add the block group item in make_btrfs()

[Josef Bacik]

Currently we build a bare-bones file system in make_btrfs(), and then we
load it up and fill in the rest of the file system after the fact.  One
thing we omit in make_btrfs() is the block group item for the temporary
system chunk we allocate, because we just add it after we've opened the
file system.

However I want to be able to generate the free space tree at
make_btrfs() time, because extent tree v2 will not have an extent tree
that has every block allocated in the system.  In order to do this I
need to make sure that the free space tree entries are added on block
group creation, which is annoying if we have to add this chunk after
I've created a free space tree.

So make future work simpler by simply adding our block group item at
make_btrfs() time, this way I can do the right things with the free
space tree in the generic make block group code without needing a
special case for our temporary system chunk.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/common.c | 31 +++++++++++++++++++++++++++++++
 mkfs/main.c   |  9 ++-------
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/mkfs/common.c b/mkfs/common.c
index a392a5b0..9b5f96e3 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -188,6 +188,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	u64 num_bytes;
 	u64 system_group_offset = BTRFS_BLOCK_RESERVED_1M_FOR_SUPER;
 	u64 system_group_size = BTRFS_MKFS_SYSTEM_GROUP_SIZE;
+	bool add_block_group = true;
 
 	if ((cfg->features & BTRFS_FEATURE_INCOMPAT_ZONED)) {
 		system_group_offset = cfg->zone_size * BTRFS_NR_SB_LOG_ZONES;
@@ -276,6 +277,36 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	for (i = 0; i < blocks_nr; i++) {
 		blk = blocks[i];
 
+		/* 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;
+
+			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++;
+		}
+
 		item_size = sizeof(struct btrfs_extent_item);
 		if (!skinny_metadata)
 			item_size += sizeof(struct btrfs_tree_block_info);
diff --git a/mkfs/main.c b/mkfs/main.c
index eab93eb3..ea53e9c7 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -67,7 +67,6 @@ static int create_metadata_block_groups(struct btrfs_root *root, int mixed,
 	struct btrfs_trans_handle *trans;
 	struct btrfs_space_info *sinfo;
 	u64 flags = BTRFS_BLOCK_GROUP_METADATA;
-	u64 bytes_used;
 	u64 chunk_start = 0;
 	u64 chunk_size = 0;
 	u64 system_group_offset = BTRFS_BLOCK_RESERVED_1M_FOR_SUPER;
@@ -90,16 +89,12 @@ static int create_metadata_block_groups(struct btrfs_root *root, int mixed,
 
 	trans = btrfs_start_transaction(root, 1);
 	BUG_ON(IS_ERR(trans));
-	bytes_used = btrfs_super_bytes_used(fs_info->super_copy);
 
 	root->fs_info->system_allocs = 1;
 	/*
-	 * First temporary system chunk must match the chunk layout
-	 * created in make_btrfs().
+	 * We already created the block group item for our temporary system
+	 * chunk in make_btrfs(), so account for the size here.
 	 */
-	ret = btrfs_make_block_group(trans, fs_info, bytes_used,
-				     BTRFS_BLOCK_GROUP_SYSTEM,
-				     system_group_offset, system_group_size);
 	allocation->system += system_group_size;
 	if (ret)
 		return ret;
-- 
2.26.3

[PATCH v2 08/10] btrfs-progs: add add_block_group_free_space helper

[Josef Bacik]

This exists in the kernel free-space-tree.c but not in progs.  We need
it to generate the free space items for new block groups, which is
needed when we start creating the free space tree in make_btrfs().

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/extent-tree.c     |  2 ++
 kernel-shared/free-space-tree.c | 26 ++++++++++++++++++++++++++
 kernel-shared/free-space-tree.h |  2 ++
 3 files changed, 30 insertions(+)

diff --git a/kernel-shared/extent-tree.c b/kernel-shared/extent-tree.c
index 056a9256..b5b43c10 100644
--- a/kernel-shared/extent-tree.c
+++ b/kernel-shared/extent-tree.c
@@ -2816,6 +2816,8 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
 	ret = btrfs_insert_item(trans, extent_root, &key, &bgi, sizeof(bgi));
 	BUG_ON(ret);
 
+	add_block_group_free_space(trans, cache);
+
 	return 0;
 }
 
diff --git a/kernel-shared/free-space-tree.c b/kernel-shared/free-space-tree.c
index 7f589dfe..1e127e31 100644
--- a/kernel-shared/free-space-tree.c
+++ b/kernel-shared/free-space-tree.c
@@ -986,6 +986,32 @@ out:
 	return ret;
 }
 
+int add_block_group_free_space(struct btrfs_trans_handle *trans,
+			       struct btrfs_block_group *block_group)
+{
+	struct btrfs_path *path;
+	int ret;
+
+	if (!btrfs_fs_compat_ro(trans->fs_info, FREE_SPACE_TREE))
+		return 0;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	ret = add_new_free_space_info(trans, block_group, path);
+	if (ret)
+		goto out;
+	ret = __add_to_free_space_tree(trans, block_group, path,
+				       block_group->start,
+				       block_group->length);
+out:
+	btrfs_free_path(path);
+	if (ret)
+		btrfs_abort_transaction(trans, ret);
+	return ret;
+}
+
 int populate_free_space_tree(struct btrfs_trans_handle *trans,
 			     struct btrfs_block_group *block_group)
 {
diff --git a/kernel-shared/free-space-tree.h b/kernel-shared/free-space-tree.h
index 3d32e167..4f6aa5fc 100644
--- a/kernel-shared/free-space-tree.h
+++ b/kernel-shared/free-space-tree.h
@@ -34,5 +34,7 @@ int add_to_free_space_tree(struct btrfs_trans_handle *trans, u64 start,
 int remove_from_free_space_tree(struct btrfs_trans_handle *trans, u64 start,
 				u64 size);
 int btrfs_create_free_space_tree(struct btrfs_fs_info *info);
+int add_block_group_free_space(struct btrfs_trans_handle *trans,
+			       struct btrfs_block_group *block_group);
 
 #endif
-- 
2.26.3

[PATCH v2 09/10] btrfs-progs: mkfs: generate free space tree at make_btrfs() time

[Josef Bacik]

With extent-tree-v2 we won't be able to cache block groups based on the
extent tree, so we need to have a valid free space tree before we open
the temporary file system to finish setting the file system up.  Set up
the basic free space entries for our temporary system chunk if we have
the free space tree enabled and stop generating the tree after the fact.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mkfs/common.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++
 mkfs/common.h |  9 +++++++
 mkfs/main.c   | 13 +++-------
 3 files changed, 82 insertions(+), 9 deletions(-)

diff --git a/mkfs/common.c b/mkfs/common.c
index 9b5f96e3..631e6d43 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -37,6 +37,7 @@ static u64 reference_root_table[] = {
 	[MKFS_DEV_TREE]		=	BTRFS_DEV_TREE_OBJECTID,
 	[MKFS_FS_TREE]		=	BTRFS_FS_TREE_OBJECTID,
 	[MKFS_CSUM_TREE]	=	BTRFS_CSUM_TREE_OBJECTID,
+	[MKFS_FREE_SPACE_TREE]	=	BTRFS_FREE_SPACE_TREE_OBJECTID,
 };
 
 static int btrfs_write_empty_tree(int fd, struct btrfs_mkfs_config *cfg,
@@ -139,6 +140,55 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
 	return ret;
 }
 
+static int create_free_space_tree(int fd, struct btrfs_mkfs_config *cfg,
+				  struct extent_buffer *buf, u64 group_start,
+				  u64 group_size, u64 free_start)
+{
+	struct btrfs_free_space_info *info;
+	struct btrfs_disk_key disk_key;
+	enum btrfs_mkfs_block blk;
+	int itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
+	int nritems = 0;
+	int i = 0;
+	int ret;
+
+	memset(buf->data + sizeof(struct btrfs_header), 0,
+	       cfg->nodesize - sizeof(struct btrfs_header));
+	itemoff -= sizeof(*info);
+
+	btrfs_set_disk_key_objectid(&disk_key, group_start);
+	btrfs_set_disk_key_offset(&disk_key, group_size);
+	btrfs_set_disk_key_type(&disk_key, BTRFS_FREE_SPACE_INFO_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(*info));
+
+	info = btrfs_item_ptr(buf, nritems, struct btrfs_free_space_info);
+	btrfs_set_free_space_extent_count(buf, info, 1);
+	btrfs_set_free_space_flags(buf, info, 0);
+
+	nritems++;
+	btrfs_set_disk_key_objectid(&disk_key, free_start);
+	btrfs_set_disk_key_offset(&disk_key, group_start + group_size -
+				  free_start);
+	btrfs_set_disk_key_type(&disk_key, BTRFS_FREE_SPACE_EXTENT_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), 0);
+
+	nritems++;
+	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_FREE_SPACE_TREE]);
+	btrfs_set_header_owner(buf, BTRFS_FREE_SPACE_TREE_OBJECTID);
+	btrfs_set_header_nritems(buf, nritems);
+	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_FREE_SPACE_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
  *
@@ -189,6 +239,12 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	u64 system_group_offset = BTRFS_BLOCK_RESERVED_1M_FOR_SUPER;
 	u64 system_group_size = BTRFS_MKFS_SYSTEM_GROUP_SIZE;
 	bool add_block_group = true;
+	bool free_space_tree = !!(cfg->runtime_features &
+				  BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE);
+
+	/* Don't include the free space tree in the blocks to process. */
+	if (!free_space_tree)
+		blocks_nr--;
 
 	if ((cfg->features & BTRFS_FEATURE_INCOMPAT_ZONED)) {
 		system_group_offset = cfg->zone_size * BTRFS_NR_SB_LOG_ZONES;
@@ -248,6 +304,11 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	else
 		btrfs_set_super_cache_generation(&super, -1);
 	btrfs_set_super_incompat_flags(&super, cfg->features);
+	if (free_space_tree) {
+		u64 ro_flags = BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE |
+			BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID;
+		btrfs_set_super_compat_ro_flags(&super, ro_flags);
+	}
 	if (cfg->label)
 		__strncpy_null(super.label, cfg->label, BTRFS_LABEL_SIZE - 1);
 
@@ -513,6 +574,14 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 	if (ret)
 		goto out;
 
+	if (free_space_tree) {
+		ret = create_free_space_tree(fd, cfg, buf, system_group_offset,
+					     system_group_size,
+					     system_group_offset + 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 f2d28057..f31b4ae4 100644
--- a/mkfs/common.h
+++ b/mkfs/common.h
@@ -51,6 +51,7 @@ enum btrfs_mkfs_block {
 	MKFS_DEV_TREE,
 	MKFS_FS_TREE,
 	MKFS_CSUM_TREE,
+	MKFS_FREE_SPACE_TREE,
 	MKFS_BLOCK_COUNT
 };
 
@@ -61,6 +62,12 @@ static const enum btrfs_mkfs_block extent_tree_v1_blocks[] = {
 	MKFS_DEV_TREE,
 	MKFS_FS_TREE,
 	MKFS_CSUM_TREE,
+
+	/*
+	 * Since the free space tree is optional with v1 it must always be last
+	 * in this array.
+	 */
+	MKFS_FREE_SPACE_TREE,
 };
 
 struct btrfs_mkfs_config {
@@ -72,6 +79,8 @@ struct btrfs_mkfs_config {
 	u32 stripesize;
 	/* Bitfield of incompat features, BTRFS_FEATURE_INCOMPAT_* */
 	u64 features;
+	/* Bitfield of BTRFS_RUNTIME_FEATURE_* */
+	u64 runtime_features;
 	/* Size of the filesystem in bytes */
 	u64 num_bytes;
 	/* checksum algorithm to use */
diff --git a/mkfs/main.c b/mkfs/main.c
index ea53e9c7..edfded1f 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -137,7 +137,6 @@ static int create_metadata_block_groups(struct btrfs_root *root, int mixed,
 
 	root->fs_info->system_allocs = 0;
 	ret = btrfs_commit_transaction(trans, root);
-
 err:
 	return ret;
 }
@@ -254,7 +253,9 @@ static int recow_roots(struct btrfs_trans_handle *trans,
 	ret = __recow_root(trans, info->csum_root);
 	if (ret)
 		return ret;
-
+	ret = __recow_root(trans, info->free_space_root);
+	if (ret)
+		return ret;
 	return 0;
 }
 
@@ -1366,6 +1367,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
 	mkfs_cfg.sectorsize = sectorsize;
 	mkfs_cfg.stripesize = stripesize;
 	mkfs_cfg.features = features;
+	mkfs_cfg.runtime_features = runtime_features;
 	mkfs_cfg.csum_type = csum_type;
 	mkfs_cfg.zone_size = zone_size(file);
 
@@ -1529,13 +1531,6 @@ raid_groups:
 			goto out;
 		}
 	}
-	if (runtime_features & BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE) {
-		ret = btrfs_create_free_space_tree(fs_info);
-		if (ret < 0) {
-			error("failed to create free space tree: %d (%m)", ret);
-			goto out;
-		}
-	}
 	if (verbose) {
 		char features_buf[64];
 
-- 
2.26.3

[PATCH v2 10/10] btrfs-progs: add the incompat flag for extent tree v2

[Josef Bacik]

I will have a lot of preparatory patches to reduce the review pain of
this large feature.  In order to enable that work define the incompat
flag.  Once all of the work lands to support the feature there will be a
patch to actually enable us to select it and manipulate file systems
with that incompat flag set.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 kernel-shared/ctree.h | 1 +
 mkfs/main.c           | 8 +++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
index 3cca6032..fb918aba 100644
--- a/kernel-shared/ctree.h
+++ b/kernel-shared/ctree.h
@@ -496,6 +496,7 @@ struct btrfs_super_block {
 #define BTRFS_FEATURE_INCOMPAT_METADATA_UUID    (1ULL << 10)
 #define BTRFS_FEATURE_INCOMPAT_RAID1C34		(1ULL << 11)
 #define BTRFS_FEATURE_INCOMPAT_ZONED		(1ULL << 12)
+#define BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2	(1ULL << 13)
 
 #define BTRFS_FEATURE_COMPAT_SUPP		0ULL
 
diff --git a/mkfs/main.c b/mkfs/main.c
index edfded1f..7ea6910e 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -253,9 +253,11 @@ static int recow_roots(struct btrfs_trans_handle *trans,
 	ret = __recow_root(trans, info->csum_root);
 	if (ret)
 		return ret;
-	ret = __recow_root(trans, info->free_space_root);
-	if (ret)
-		return ret;
+	if (info->free_space_root) {
+		ret = __recow_root(trans, info->free_space_root);
+		if (ret)
+			return ret;
+	}
 	return 0;
 }
 
-- 
2.26.3

Re: [PATCH v2 00/10] btrfs-progs: mkfs fixes and prep work for extent tree v2

[David Sterba]

On Mon, Aug 23, 2021 at 04:14:45PM -0400, Josef Bacik wrote:
> In order to reduce the amount of pain the reviewers have to endure I'm going to
> be sending any prepatory patches separately from the actual feature work.
> 
> To that end this is the first batch of preparatory patches.  These are to make
> working with mkfs a lot easier for the changes I'm making.  These are all fixes
> or enhancements that can apply currently.  The only thing that is extent tree v2
> specific is the last patch, which adds the incompat flag.
> 
> I've added the patch for the incompat flag because I will have other preparatory
> patches that add helpers that essentially do
> 
> if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
> 	/* Do the old thing. */
> 
> and then have patches after that add the extent tree v2 magic.  I think this
> will make it easier to break up the work, but if we're not comfortable reserving
> the bit then I'm fine with dropping that last patch.  It will just mean future
> prep work will have to come along with the feature enablement patches.

Going through the patches I don't think mentioning the extent tree v2
makes sense in case the patch is an independent cleanup or refactors
some code to be a bit more generic.

The actual incompat bit could be reserved but it would be better to keep
it in the future patchset implementing some significant part of the
extent tree v2.

Even with the "if (EXTENT_TREE_V2)" in place it becomes the
implementation and given that I haven't read the whole design doc for
that I'm worried that once I find time for that and would suggest some
changes the reply would be "no I did it this way, it's implemented,
would require too many changes".

Would be good to keep mentioning the v2 tree maybe to the cover letter
so we know what's the motivation but in the changelogs it's confusing as
we don't have any base point for that.

Re: [PATCH v2 00/10] btrfs-progs: mkfs fixes and prep work for extent tree v2

[David Sterba]

On Wed, Aug 25, 2021 at 03:58:39PM +0200, David Sterba wrote:
> On Mon, Aug 23, 2021 at 04:14:45PM -0400, Josef Bacik wrote:
> > In order to reduce the amount of pain the reviewers have to endure I'm going to
> > be sending any prepatory patches separately from the actual feature work.
> > 
> > To that end this is the first batch of preparatory patches.  These are to make
> > working with mkfs a lot easier for the changes I'm making.  These are all fixes
> > or enhancements that can apply currently.  The only thing that is extent tree v2
> > specific is the last patch, which adds the incompat flag.
> > 
> > I've added the patch for the incompat flag because I will have other preparatory
> > patches that add helpers that essentially do
> > 
> > if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
> > 	/* Do the old thing. */
> > 
> > and then have patches after that add the extent tree v2 magic.  I think this
> > will make it easier to break up the work, but if we're not comfortable reserving
> > the bit then I'm fine with dropping that last patch.  It will just mean future
> > prep work will have to come along with the feature enablement patches.
> 
> Going through the patches I don't think mentioning the extent tree v2
> makes sense in case the patch is an independent cleanup or refactors
> some code to be a bit more generic.

I've rephrased some of the changelogs regarding v2.

> The actual incompat bit could be reserved but it would be better to keep
> it in the future patchset implementing some significant part of the
> extent tree v2.
> 
> Even with the "if (EXTENT_TREE_V2)" in place it becomes the
> implementation and given that I haven't read the whole design doc for
> that I'm worried that once I find time for that and would suggest some
> changes the reply would be "no I did it this way, it's implemented,
> would require too many changes".

The design is still flexile enough for the questions I had so we can
proceed.

> Would be good to keep mentioning the v2 tree maybe to the cover letter
> so we know what's the motivation but in the changelogs it's confusing as
> we don't have any base point for that.

So the plan is to merge it as the experimental feature and patches will
arrive, which means referencing v2 extent tree is ok and you can keep
using it.

Patches added to devel.

Re: [PATCH v2 09/10] btrfs-progs: mkfs: generate free space tree at make_btrfs() time

[Qu Wenruo]

On 2021/8/24 04:14, Josef Bacik wrote:
> With extent-tree-v2 we won't be able to cache block groups based on the
> extent tree, so we need to have a valid free space tree before we open
> the temporary file system to finish setting the file system up.  Set up
> the basic free space entries for our temporary system chunk if we have
> the free space tree enabled and stop generating the tree after the fact.
>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>

Just to note a new regression exposed recently.

This patch is making mkfs.btrfs to leave some SINGLE metadata left
uncleaned, if "-R free-space-tree -d DUP" is specified.

"-d DUP" part is needed just to make data profile to be non-SINGLE, and
is required to reproduce the bug.

Before this patch:
  # mkfs.btrfs -f -R free-space-tree -d DUP /dev/test/test
  # btrfs ins dump-tree -t chunk /dev/test/test | grep "type METADATA"
    length 268435456 owner 2 stripe_len 65536 type METADATA|DUP

After this patch:
  # mkfs.btrfs -f -R free-space-tree -d DUP /dev/test/test
  # btrfs ins dump-tree -t chunk /dev/test/test | grep "type METADATA"
    length 8388608 owner 2 stripe_len 65536 type METADATA
    length 268435456 owner 2 stripe_len 65536 type METADATA|DUP

It is not a big deal, as kernel can automatically remove it, but with
recent btrfs-progs update, it can cause extra warning:

   $ sudo btrfs fi df /mnt/btrfs/
   Data, DUP: total=1.00GiB, used=0.00B
   System, DUP: total=8.00MiB, used=16.00KiB
   Metadata, DUP: total=256.00MiB, used=176.00KiB
   Metadata, single: total=8.00MiB, used=0.00B
   GlobalReserve, single: total=3.25MiB, used=0.00B
   WARNING: Multiple block group profiles detected, see 'man btrfs(5)'.
   WARNING:   Metadata: single, dup


The root cause is the timing of free space cache creation, it's still
created when the initial temporary fs is created.

Thus it's using SINGLE metadata.

Although we later migrated to the new metadata profile, by somehow the
empty metadata chunk is not properly cleared at mkfs time.

I'll investigate on why cleanup_temp_chunks() is not working properly
for this new case.

Thanks,
Qu
> ---
>   mkfs/common.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++
>   mkfs/common.h |  9 +++++++
>   mkfs/main.c   | 13 +++-------
>   3 files changed, 82 insertions(+), 9 deletions(-)
>
> diff --git a/mkfs/common.c b/mkfs/common.c
> index 9b5f96e3..631e6d43 100644
> --- a/mkfs/common.c
> +++ b/mkfs/common.c
> @@ -37,6 +37,7 @@ static u64 reference_root_table[] = {
>   	[MKFS_DEV_TREE]		=	BTRFS_DEV_TREE_OBJECTID,
>   	[MKFS_FS_TREE]		=	BTRFS_FS_TREE_OBJECTID,
>   	[MKFS_CSUM_TREE]	=	BTRFS_CSUM_TREE_OBJECTID,
> +	[MKFS_FREE_SPACE_TREE]	=	BTRFS_FREE_SPACE_TREE_OBJECTID,
>   };
>
>   static int btrfs_write_empty_tree(int fd, struct btrfs_mkfs_config *cfg,
> @@ -139,6 +140,55 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
>   	return ret;
>   }
>
> +static int create_free_space_tree(int fd, struct btrfs_mkfs_config *cfg,
> +				  struct extent_buffer *buf, u64 group_start,
> +				  u64 group_size, u64 free_start)
> +{
> +	struct btrfs_free_space_info *info;
> +	struct btrfs_disk_key disk_key;
> +	enum btrfs_mkfs_block blk;
> +	int itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
> +	int nritems = 0;
> +	int i = 0;
> +	int ret;
> +
> +	memset(buf->data + sizeof(struct btrfs_header), 0,
> +	       cfg->nodesize - sizeof(struct btrfs_header));
> +	itemoff -= sizeof(*info);
> +
> +	btrfs_set_disk_key_objectid(&disk_key, group_start);
> +	btrfs_set_disk_key_offset(&disk_key, group_size);
> +	btrfs_set_disk_key_type(&disk_key, BTRFS_FREE_SPACE_INFO_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(*info));
> +
> +	info = btrfs_item_ptr(buf, nritems, struct btrfs_free_space_info);
> +	btrfs_set_free_space_extent_count(buf, info, 1);
> +	btrfs_set_free_space_flags(buf, info, 0);
> +
> +	nritems++;
> +	btrfs_set_disk_key_objectid(&disk_key, free_start);
> +	btrfs_set_disk_key_offset(&disk_key, group_start + group_size -
> +				  free_start);
> +	btrfs_set_disk_key_type(&disk_key, BTRFS_FREE_SPACE_EXTENT_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), 0);
> +
> +	nritems++;
> +	btrfs_set_header_bytenr(buf, cfg->blocks[MKFS_FREE_SPACE_TREE]);
> +	btrfs_set_header_owner(buf, BTRFS_FREE_SPACE_TREE_OBJECTID);
> +	btrfs_set_header_nritems(buf, nritems);
> +	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_FREE_SPACE_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
>    *
> @@ -189,6 +239,12 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
>   	u64 system_group_offset = BTRFS_BLOCK_RESERVED_1M_FOR_SUPER;
>   	u64 system_group_size = BTRFS_MKFS_SYSTEM_GROUP_SIZE;
>   	bool add_block_group = true;
> +	bool free_space_tree = !!(cfg->runtime_features &
> +				  BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE);
> +
> +	/* Don't include the free space tree in the blocks to process. */
> +	if (!free_space_tree)
> +		blocks_nr--;
>
>   	if ((cfg->features & BTRFS_FEATURE_INCOMPAT_ZONED)) {
>   		system_group_offset = cfg->zone_size * BTRFS_NR_SB_LOG_ZONES;
> @@ -248,6 +304,11 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
>   	else
>   		btrfs_set_super_cache_generation(&super, -1);
>   	btrfs_set_super_incompat_flags(&super, cfg->features);
> +	if (free_space_tree) {
> +		u64 ro_flags = BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE |
> +			BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID;
> +		btrfs_set_super_compat_ro_flags(&super, ro_flags);
> +	}
>   	if (cfg->label)
>   		__strncpy_null(super.label, cfg->label, BTRFS_LABEL_SIZE - 1);
>
> @@ -513,6 +574,14 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
>   	if (ret)
>   		goto out;
>
> +	if (free_space_tree) {
> +		ret = create_free_space_tree(fd, cfg, buf, system_group_offset,
> +					     system_group_size,
> +					     system_group_offset + 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 f2d28057..f31b4ae4 100644
> --- a/mkfs/common.h
> +++ b/mkfs/common.h
> @@ -51,6 +51,7 @@ enum btrfs_mkfs_block {
>   	MKFS_DEV_TREE,
>   	MKFS_FS_TREE,
>   	MKFS_CSUM_TREE,
> +	MKFS_FREE_SPACE_TREE,
>   	MKFS_BLOCK_COUNT
>   };
>
> @@ -61,6 +62,12 @@ static const enum btrfs_mkfs_block extent_tree_v1_blocks[] = {
>   	MKFS_DEV_TREE,
>   	MKFS_FS_TREE,
>   	MKFS_CSUM_TREE,
> +
> +	/*
> +	 * Since the free space tree is optional with v1 it must always be last
> +	 * in this array.
> +	 */
> +	MKFS_FREE_SPACE_TREE,
>   };
>
>   struct btrfs_mkfs_config {
> @@ -72,6 +79,8 @@ struct btrfs_mkfs_config {
>   	u32 stripesize;
>   	/* Bitfield of incompat features, BTRFS_FEATURE_INCOMPAT_* */
>   	u64 features;
> +	/* Bitfield of BTRFS_RUNTIME_FEATURE_* */
> +	u64 runtime_features;
>   	/* Size of the filesystem in bytes */
>   	u64 num_bytes;
>   	/* checksum algorithm to use */
> diff --git a/mkfs/main.c b/mkfs/main.c
> index ea53e9c7..edfded1f 100644
> --- a/mkfs/main.c
> +++ b/mkfs/main.c
> @@ -137,7 +137,6 @@ static int create_metadata_block_groups(struct btrfs_root *root, int mixed,
>
>   	root->fs_info->system_allocs = 0;
>   	ret = btrfs_commit_transaction(trans, root);
> -
>   err:
>   	return ret;
>   }
> @@ -254,7 +253,9 @@ static int recow_roots(struct btrfs_trans_handle *trans,
>   	ret = __recow_root(trans, info->csum_root);
>   	if (ret)
>   		return ret;
> -
> +	ret = __recow_root(trans, info->free_space_root);
> +	if (ret)
> +		return ret;
>   	return 0;
>   }
>
> @@ -1366,6 +1367,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
>   	mkfs_cfg.sectorsize = sectorsize;
>   	mkfs_cfg.stripesize = stripesize;
>   	mkfs_cfg.features = features;
> +	mkfs_cfg.runtime_features = runtime_features;
>   	mkfs_cfg.csum_type = csum_type;
>   	mkfs_cfg.zone_size = zone_size(file);
>
> @@ -1529,13 +1531,6 @@ raid_groups:
>   			goto out;
>   		}
>   	}
> -	if (runtime_features & BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE) {
> -		ret = btrfs_create_free_space_tree(fs_info);
> -		if (ret < 0) {
> -			error("failed to create free space tree: %d (%m)", ret);
> -			goto out;
> -		}
> -	}
>   	if (verbose) {
>   		char features_buf[64];
>
>

Re: [PATCH v2 00/10] btrfs-progs: mkfs fixes and prep work for extent tree v2

[Goffredo Baroncelli]

On 8/25/21 3:58 PM, David Sterba wrote:
> On Mon, Aug 23, 2021 at 04:14:45PM -0400, Josef Bacik wrote:
[...]
> Even with the "if (EXTENT_TREE_V2)" in place it becomes the
> implementation and given that I haven't read the whole design doc for
> that I'm worried that once I find time for that and would suggest some
> changes the reply would be "no I did it this way, it's implemented,
> would require too many changes".

Just for curiosity, is there anywhere a design doc for extent tree v2 ?

BR
-- 
gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D  17B2 0EDA 9B37 8B82 E0B5

Re: [PATCH v2 00/10] btrfs-progs: mkfs fixes and prep work for extent tree v2

[David Sterba]

On Mon, Oct 11, 2021 at 08:35:53PM +0200, Goffredo Baroncelli wrote:
> On 8/25/21 3:58 PM, David Sterba wrote:
> > On Mon, Aug 23, 2021 at 04:14:45PM -0400, Josef Bacik wrote:
> [...]
> > Even with the "if (EXTENT_TREE_V2)" in place it becomes the
> > implementation and given that I haven't read the whole design doc for
> > that I'm worried that once I find time for that and would suggest some
> > changes the reply would be "no I did it this way, it's implemented,
> > would require too many changes".
> 
> Just for curiosity, is there anywhere a design doc for extent tree v2 ?

https://github.com/btrfs/btrfs-todo/issues/25 but it's more like an
ongoing discussion than a polished design doc, that's about to be a
result of that some day.

Re: [PATCH v2 00/10] btrfs-progs: mkfs fixes and prep work for extent tree v2

[Goffredo Baroncelli]

On 10/11/21 8:47 PM, David Sterba wrote:
> On Mon, Oct 11, 2021 at 08:35:53PM +0200, Goffredo Baroncelli wrote:
>> On 8/25/21 3:58 PM, David Sterba wrote:
>>> On Mon, Aug 23, 2021 at 04:14:45PM -0400, Josef Bacik wrote:
>> [...]
>>> Even with the "if (EXTENT_TREE_V2)" in place it becomes the
>>> implementation and given that I haven't read the whole design doc for
>>> that I'm worried that once I find time for that and would suggest some
>>> changes the reply would be "no I did it this way, it's implemented,
>>> would require too many changes".
>>
>> Just for curiosity, is there anywhere a design doc for extent tree v2 ?
> 
> https://github.com/btrfs/btrfs-todo/issues/25 but it's more like an
> ongoing discussion than a polished design doc, that's about to be a
> result of that some day.
> 
Thanks, very interesting reading...

-- 
gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D  17B2 0EDA 9B37 8B82 E0B5