From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Tue, 8 Feb 2022 18:38:23 +0000 (-0500)
Subject: NFS: LOOKUP_DIRECTORY is also ok with symlinks
X-Git-Tag: baikal/aarch64/sdk6.1~4634^2~1
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=b5e74e9f9adf3c162dfdd01e771426de3dc2900a;p=kernel.git

NFS: LOOKUP_DIRECTORY is also ok with symlinks

Commit dc49d2152c0f (NFSv4: Handle case where the lookup of a directory
fails) [1], part of Linux since 5.17-rc2, introduced a regression, where
a symbolic link on an NFS mount to a directory on another NFS does not
resolve(?) the first time it is accessed:

Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Fixes: dc49d2152c0f ("NFSv4: Handle case where the lookup of a directory fails")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
---

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 7bc7cf6b26f09..75cb1cbe4cdea 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2010,14 +2010,14 @@ no_open:
 	if (!res) {
 		inode = d_inode(dentry);
 		if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
-		    !S_ISDIR(inode->i_mode))
+		    !(S_ISDIR(inode->i_mode) || S_ISLNK(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)) {
+		    !(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) {
 			dput(res);
 			res = ERR_PTR(-ENOTDIR);
 		} else if (inode && S_ISREG(inode->i_mode)) {