[PATCH] cifs: don't use CIFSGetSrvInodeNumber in is_path_accessible

Because it's lighter weight, CIFS tries to do a QPathInfo call with an
infolevel of SMB_QUERY_FILE_INTERNAL_INFO to verify the accessibility of
the root inode. It then falls back to using an infolevel of
SMB_QUERY_FILE_ALL_INFO if that fails with -EOPNOTSUPP.

There's a problem however. SMB_QUERY_FILE_INTERNAL_INFO isn't as well
supported by all servers as SMB_QUERY_FILE_ALL_INFO is, and the error
returns from those servers aren't well standardized. I have at least one
report of a server that returns NT_STATUS_INTERNAL_ERROR (which
translates to EIO) rather than something that translates to EOPNOTSUPP.

Given that that function only gets called at mount time, I think it's
better to do this as simply as possible. Rather than trying to be
clever, just have is_path_accessible use SMB_QUERY_FILE_ALL_INFO. That
call is widely supported and it shouldn't increase the overhead
significantly.

Unfortunately, the reporter of this problem doesn't seem to be in a
hurry to test it, so I don't have any test results from it. Given what I
see in the captures though, I expect that this will fix the problem.

Signed-off-by: Jeff Layton <[email protected]>
---
 fs/cifs/connect.c |    8 --------
 1 files changed, 0 insertions(+), 8 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index b090980..63ea83f 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2220,16 +2220,8 @@ is_path_accessible(int xid, struct cifsTconInfo *tcon,
 		   struct cifs_sb_info *cifs_sb, const char *full_path)
 {
 	int rc;
-	__u64 inode_num;
 	FILE_ALL_INFO *pfile_info;
 
-	rc = CIFSGetSrvInodeNumber(xid, tcon, full_path, &inode_num,
-				   cifs_sb->local_nls,
-				   cifs_sb->mnt_cifs_flags &
-						CIFS_MOUNT_MAP_SPECIAL_CHR);
-	if (rc != -EOPNOTSUPP)
-		return rc;
-
 	pfile_info = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 	if (pfile_info == NULL)
 		return -ENOMEM;
-- 
1.6.0.6