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: 0dd2b474d0b6 ("nfs: implement i_op->atomic_open()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 408c3bb549b1e13428fa6ea219d62b3a8835b906..5df75ed092685cf3cd2c1e1de0a4b79ed653010a 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1999,12 +1999,17 @@ no_open:
                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) {