hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

btrfs: release path before calling to btrfs_load_block_group_zone_info 

Since we have no write pointer in conventional zones, we cannot
determine the allocation offset from it. Instead, we set the allocation
offset after the highest addressed extent. This is done by reading the
extent tree in btrfs_load_block_group_zone_info().

However, this function is called from btrfs_read_block_groups(), so the
read lock for the tree node could be recursively taken.

To avoid this unsafe locking scenario, release the path before reading
the extent tree to get the allocation offset.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Johannes Thumshirn 2021-02-04 19:21:44 +09:00 committed by David Sterba
parent d6639b35da
commit 4afd2fe835
1 changed files with 17 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
fs/btrfs/block-group.c
View File

@ -1810,24 +1810,8 @@ static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
return ret;
}
static void read_block_group_item(struct btrfs_block_group *cache,
struct btrfs_path *path,
const struct btrfs_key *key)
{
struct extent_buffer *leaf = path->nodes[0];
struct btrfs_block_group_item bgi;
int slot = path->slots[0];
cache->length = key->offset;
read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
sizeof(bgi));
cache->used = btrfs_stack_block_group_used(&bgi);
cache->flags = btrfs_stack_block_group_flags(&bgi);
}
static int read_one_block_group(struct btrfs_fs_info *info,
struct btrfs_path *path,
struct btrfs_block_group_item *bgi,
const struct btrfs_key *key,
int need_clear)
{
@ -1842,7 +1826,9 @@ static int read_one_block_group(struct btrfs_fs_info *info,
if (!cache)
return -ENOMEM;
read_block_group_item(cache, path, key);
cache->length = key->offset;
cache->used = btrfs_stack_block_group_used(bgi);
cache->flags = btrfs_stack_block_group_flags(bgi);
set_free_space_tree_thresholds(cache);
@ -2001,19 +1987,29 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
need_clear = 1;
while (1) {
struct btrfs_block_group_item bgi;
struct extent_buffer *leaf;
int slot;
ret = find_first_block_group(info, path, &key);
if (ret > 0)
break;
if (ret != 0)
goto error;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
ret = read_one_block_group(info, path, &key, need_clear);
leaf = path->nodes[0];
slot = path->slots[0];
read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
sizeof(bgi));
btrfs_item_key_to_cpu(leaf, &key, slot);
btrfs_release_path(path);
ret = read_one_block_group(info, &bgi, &key, need_clear);
if (ret < 0)
goto error;
key.objectid += key.offset;
key.offset = 0;
btrfs_release_path(path);
}
btrfs_release_path(path);