NFSv4: nfs_atomic_open() can race when looking up a non-regular file

If the file type changes back to being a regular file on the server between the failed OPEN and our LOOKUP, then we need to re-run the OPEN. Fixes: 0dd2b47 ("nfs: implement i_op->atomic_open()") Signed-off-by: Trond Myklebust <[email protected]> Signed-off-by: Anna Schumaker <[email protected]>
pop-os · Jan 7, 2022 · 1751fc1 · 1751fc1
1 parent ac79516
commit 1751fc1
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
@@ -1999,12 +1999,17 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
 		if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
 		    !S_ISDIR(inode->i_mode))
 			res = ERR_PTR(-ENOTDIR);
+		else if (inode && S_ISREG(inode->i_mode))
+			res = ERR_PTR(-EOPENSTALE);
 	} else if (!IS_ERR(res)) {
 		inode = d_inode(res);
 		if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
 		    !S_ISDIR(inode->i_mode)) {
 			dput(res);
 			res = ERR_PTR(-ENOTDIR);
+		} else if (inode && S_ISREG(inode->i_mode)) {
+			dput(res);
+			res = ERR_PTR(-EOPENSTALE);
 		}
 	}
 	if (switched) {