diff options
| author | Kent Overstreet <kent.overstreet@linux.dev> | 2025-05-14 13:40:47 -0400 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2025-05-14 17:05:19 -0400 |
| commit | a12cb6f758177fcf9bdb7d18b4724eaa29023740 (patch) | |
| tree | 35d86a97aec43455b9e3cc291fd4a3f93fe2f1d0 | |
| parent | 43b9fece2d9687cde58cc7eec4548dd1c35e2198 (diff) | |
bcachefs: Fix accidental O(n^2) in fiemap
Since bch2_seek_pagecache_data() searches for dirty data, we only want
to call it for holes in the extents btree - otherwise we have an
accidental O(n^2), as we repeatedly search the same range.
Reported-by: Marcin Mirosław <marcin@mejor.pl>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
| -rw-r--r-- | fs/bcachefs/fs.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c index b6801861c66f..4b742e62255b 100644 --- a/fs/bcachefs/fs.c +++ b/fs/bcachefs/fs.c @@ -1429,7 +1429,9 @@ static int bch2_next_fiemap_extent(struct btree_trans *trans, if (ret) goto err; - ret = bch2_next_fiemap_pagecache_extent(trans, inode, start, end, cur); + u64 pagecache_end = k.k ? max(start, bkey_start_offset(k.k)) : end; + + ret = bch2_next_fiemap_pagecache_extent(trans, inode, start, pagecache_end, cur); if (ret) goto err; |