Re: [syzbot] [f2fs?] WARNING: lock held when returning to user space in f2fs_commit_atomic_write

From: Edward Adam Davis
Date: Tue Aug 13 2024 - 20:48:55 EST


unlock i_gc_rwsem[WRITE] before quiting f2fs_commit_atomic_write

Fixes: 7566a155c666 ("f2fs: atomic: fix to not allow GC to pollute atomic_file")
Reported-by: syzbot+78ff2855f26377625419@xxxxxxxxxxxxxxxxxxxxxxxxx

#syz test: net-next 9e6869691724

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 741e46f9d0fd..a43054ab0cf1 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -389,13 +389,13 @@ int f2fs_commit_atomic_write(struct inode *inode)

err = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
if (err)
- return err;
+ goto out;

/* writeback GCing page of cow_inode */
err = filemap_write_and_wait_range(fi->cow_inode->i_mapping,
0, LLONG_MAX);
if (err)
- return err;
+ goto out;

filemap_invalidate_lock(inode->i_mapping);

@@ -407,6 +407,7 @@ int f2fs_commit_atomic_write(struct inode *inode)
f2fs_unlock_op(sbi);

filemap_invalidate_unlock(inode->i_mapping);
+out:
f2fs_up_write(&fi->i_gc_rwsem[WRITE]);

return err;