[PATCH 06/17] btrfs: set the lockdep class for log tree extent buffers

Josef Bacik
2020-08-10T15:43:00Z

These are special extent buffers that get rewound in order to lookup
the state of the tree at a specific point in time. As such they do not
go through the normal initialization paths that set their lockdep class,
so handle them appropriately when they are created and before they are
locked.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/ctree.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 70e49d8d4f6c..cbacf700b68b 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1297,6 +1297,8 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
btrfs_tree_read_unlock_blocking(eb);
free_extent_buffer(eb);

+ btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb_rewin),
+ eb_rewin, btrfs_header_level(eb_rewin));
btrfs_tree_read_lock(eb_rewin);
__tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm);
WARN_ON(btrfs_header_nritems(eb_rewin) >
@@ -1370,7 +1372,6 @@ get_old_root(struct btrfs_root *root, u64 time_seq)

if (!eb)
return NULL;
- btrfs_tree_read_lock(eb);
if (old_root) {
btrfs_set_header_bytenr(eb, eb->start);
btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV);
@@ -1378,6 +1379,9 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
btrfs_set_header_level(eb, old_root->level);
btrfs_set_header_generation(eb, old_generation);
}
+ btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb), eb,
+ btrfs_header_level(eb));
+ btrfs_tree_read_lock(eb);
if (tm)
__tree_mod_log_rewind(fs_info, eb, time_seq, tm);
else
--
2.24.1