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

commit 1751fc1db3 upstream.

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: 0dd2b474d0 ("nfs: implement i_op->atomic_open()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Trond Myklebust 2022-01-06 18:24:03 -05:00 committed by Greg Kroah-Hartman
parent 0dfacee400
commit 4fd45ff2b4

View file

@ -1643,12 +1643,17 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
if ((lookup_flags & LOOKUP_DIRECTORY) && inode && if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
!S_ISDIR(inode->i_mode)) !S_ISDIR(inode->i_mode))
res = ERR_PTR(-ENOTDIR); res = ERR_PTR(-ENOTDIR);
else if (inode && S_ISREG(inode->i_mode))
res = ERR_PTR(-EOPENSTALE);
} else if (!IS_ERR(res)) { } else if (!IS_ERR(res)) {
inode = d_inode(res); inode = d_inode(res);
if ((lookup_flags & LOOKUP_DIRECTORY) && inode && if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
!S_ISDIR(inode->i_mode)) { !S_ISDIR(inode->i_mode)) {
dput(res); dput(res);
res = ERR_PTR(-ENOTDIR); res = ERR_PTR(-ENOTDIR);
} else if (inode && S_ISREG(inode->i_mode)) {
dput(res);
res = ERR_PTR(-EOPENSTALE);
} }
} }
if (switched) { if (switched) {