btrfs_lock_and_flush_ordered_range() loads given "*cached_state" into
cachedp, which, in general, is NULL. Then, lock_extent_bits() updates
"cachedp", but it never goes backs to the caller. Thus the caller still
see its "cached_state" to be NULL and never free the state allocated
under btrfs_lock_and_flush_ordered_range(). As a result, we will
see massive state leak with e.g. fstests btrfs/005. Fix this bug by
properly handling the pointers.
Fixes: bd80d94efb83 ("btrfs: Always use a cached extent_state in btrfs_lock_and_flush_ordered_range")
Signed-off-by: Naohiro Aota <naohiro.aota@xxxxxxx>
---
fs/btrfs/ordered-data.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index df02ed25b7db..ab31b1a1b624 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -982,13 +982,14 @@ void btrfs_lock_and_flush_ordered_range(struct extent_io_tree *tree,
struct extent_state **cached_state)
{
struct btrfs_ordered_extent *ordered;
- struct extent_state *cachedp = NULL;
+ struct extent_state *cache = NULL;
+ struct extent_state **cachedp = &cache;
if (cached_state)
- cachedp = *cached_state;
+ cachedp = cached_state;
while (1) {
- lock_extent_bits(tree, start, end, &cachedp);
+ lock_extent_bits(tree, start, end, cachedp);
ordered = btrfs_lookup_ordered_range(inode, start,
end - start + 1);
if (!ordered) {
@@ -998,10 +999,10 @@ void btrfs_lock_and_flush_ordered_range(struct extent_io_tree *tree,
* aren't exposing it outside of this function
*/
if (!cached_state)
- refcount_dec(&cachedp->refs);
+ refcount_dec(&cache->refs);
break;
}
- unlock_extent_cached(tree, start, end, &cachedp);
+ unlock_extent_cached(tree, start, end, cachedp);
btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
}
--
2.22.0
