[PATCH 04/31] btrfs: use find_first_extent_bit in btrfs_clean_io_failure

Josef Bacik
2022-09-02T20:17:06Z

Currently we're using find_first_extent_bit_state to check if our state
contains the given failrec range, however this is more of an internal
extent_io_tree helper, and is technically unsafe to use because we're
accessing the state outside of the extent_io_tree lock.

Instead use the normal helper find_first_extent_bit which returns the
range of the extent state we find in find_first_extent_bit_state and use
that to do our sanity checking.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/extent_io.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c15a6433d43c..598cb66f65df 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2395,9 +2395,10 @@ int btrfs_clean_io_failure(struct btrfs_inode *inode, u64 start,
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct extent_io_tree *io_tree = &inode->io_tree;
u64 ino = btrfs_ino(inode);
+ u64 locked_start, locked_end;
struct io_failure_record *failrec;
- struct extent_state *state;
int mirror;
+ int ret;

failrec = get_failrec(inode, start);
if (IS_ERR(failrec))
@@ -2408,14 +2409,10 @@ int btrfs_clean_io_failure(struct btrfs_inode *inode, u64 start,
if (sb_rdonly(fs_info->sb))
goto out;

- spin_lock(&io_tree->lock);
- state = find_first_extent_bit_state(io_tree,
- failrec->bytenr,
- EXTENT_LOCKED);
- spin_unlock(&io_tree->lock);
-
- if (!state || state->start > failrec->bytenr ||
- state->end < failrec->bytenr + failrec->len - 1)
+ ret = find_first_extent_bit(io_tree, failrec->bytenr, &locked_start,
+ &locked_end, EXTENT_LOCKED, NULL);
+ if (ret || locked_start > failrec->bytenr ||
+ locked_end < failrec->bytenr + failrec->len - 1)
goto out;

mirror = failrec->this_mirror;
--
2.26.3