From: Zhihao Cheng chengzhihao1@huawei.com
[ Upstream commit 25fce616a61fc2f1821e4a9ce212d0e064707093 ]
If target inode is a special file (eg. block/char device) with nlink count greater than 1, the inode with ui->data will be re-written on disk. However, UBIFS losts target inode's data_len while doing space budget. Bad space budget may let make_reservation() return with -ENOSPC, which could turn ubifs to read-only mode in do_writepage() process.
Fetch a reproducer in [Link].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216494 Fixes: 1e51764a3c2ac0 ("UBIFS: add new flash file system") Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ubifs/dir.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index f193caae69c20..e7c36e3a9b9e1 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -1320,6 +1320,8 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (unlink) { ubifs_assert(c, inode_is_locked(new_inode));
+ /* Budget for old inode's data when its nlink > 1. */ + req.dirtied_ino_d = ALIGN(ubifs_inode(new_inode)->data_len, 8); err = ubifs_purge_xattrs(new_inode); if (err) return err;