cifs: We do not drop reference to tlink in CIFSCheckMFSymlink()

When we obtain tcon from cifs_sb, we use cifs_sb_tlink() to first obtain
tlink which also grabs a reference to it. We do not drop this reference
to tlink once we are done with the call.

The patch fixes this issue by instead passing tcon as a parameter and
avoids having to obtain a reference to the tlink. A lookup for the tcon
is already made in the calling functions and this way we avoid having to
re-run the lookup. This is also consistent with the argument list for
other similar calls for M-F symlinks.

We should also return an ENOSYS when we do not find a protocol specific
function to lookup the MF Symlink data.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index aa3397620342..2c29db6a247e 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -477,9 +477,10 @@ extern int CIFSGetExtAttr(const unsigned int xid, struct cifs_tcon *tcon,
 			const int netfid, __u64 *pExtAttrBits, __u64 *pMask);
 extern void cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb);
 extern bool CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr);
-extern int CIFSCheckMFSymlink(struct cifs_fattr *fattr,
-		const unsigned char *path,
-		struct cifs_sb_info *cifs_sb, unsigned int xid);
+extern int CIFSCheckMFSymlink(unsigned int xid, struct cifs_tcon *tcon,
+			      struct cifs_sb_info *cifs_sb,
+			      struct cifs_fattr *fattr,
+			      const unsigned char *path);
 extern int mdfour(unsigned char *, unsigned char *, int);
 extern int E_md4hash(const unsigned char *passwd, unsigned char *p16,
 			const struct nls_table *codepage);