diff options
authorTheodore Ts'o <>2019-11-11 22:18:13 -0500
committerGreg Kroah-Hartman <>2019-12-17 20:39:58 +0100
commitd5a2955049171e48feba628e60f15206689bba94 (patch)
parentcf9e11a310348a49ed481195ea6d686d3a3bfd1c (diff)
ext4: work around deleting a file with i_nlink == 0 safely
commit c7df4a1ecb8579838ec8c56b2bb6a6716e974f37 upstream. If the file system is corrupted such that a file's i_links_count is too small, then it's possible that when unlinking that file, i_nlink will already be zero. Previously we were working around this kind of corruption by forcing i_nlink to one; but we were doing this before trying to delete the directory entry --- and if the file system is corrupted enough that ext4_delete_entry() fails, then we exit with i_nlink elevated, and this causes the orphan inode list handling to be FUBAR'ed, such that when we unmount the file system, the orphan inode list can get corrupted. A better way to fix this is to simply skip trying to call drop_nlink() if i_nlink is already zero, thus moving the check to the place where it makes the most sense. Link: Signed-off-by: Theodore Ts'o <> Cc: Reviewed-by: Andreas Dilger <> Signed-off-by: Greg Kroah-Hartman <>
1 files changed, 5 insertions, 6 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 212b01861d94..b4e0c270def4 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3065,18 +3065,17 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
if (IS_DIRSYNC(dir))
- if (inode->i_nlink == 0) {
- ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
- dentry->d_name.len, dentry->;
- set_nlink(inode, 1);
- }
retval = ext4_delete_entry(handle, dir, de, bh);
if (retval)
goto end_unlink;
dir->i_ctime = dir->i_mtime = current_time(dir);
ext4_mark_inode_dirty(handle, dir);
- drop_nlink(inode);
+ if (inode->i_nlink == 0)
+ ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
+ dentry->d_name.len, dentry->;
+ else
+ drop_nlink(inode);
if (!inode->i_nlink)
ext4_orphan_add(handle, inode);
inode->i_ctime = current_time(inode);