[RFC,v2] fs: introduce check for inode nlink when delete
Commit Message
From: Cheng Lin <cheng.lin130@zte.com.cn>
Do not delete inode which nlink already zero to avoid
inode nlink underflow.
Signed-off-by: Cheng Lin <cheng.lin130@zte.com.cn>
---
fs/namei.c | 9 +++++++++
1 file changed, 9 insertions(+)
@@ -4197,6 +4197,11 @@ int vfs_rmdir(struct mnt_idmap *idmap, struct inode *dir,
if (error)
goto out;
+ if (unlikely(dir->i_nlink == 0) ||
+ unlikely(dentry->d_inode->i_nlink == 0)) {
+ error = -EUCLEAN;
+ goto out;
+ }
error = dir->i_op->rmdir(dir, dentry);
if (error)
goto out;
@@ -4326,6 +4331,10 @@ int vfs_unlink(struct mnt_idmap *idmap, struct inode *dir,
error = try_break_deleg(target, delegated_inode);
if (error)
goto out;
+ if (unlikely(target->i_nlink == 0)) {
+ error = -EUCLEAN;
+ goto out;
+ }
error = dir->i_op->unlink(dir, dentry);
if (!error) {
dont_mount(dentry);