[CIFS] Fix cifsacl mounts over smb2 to not call cifs

When mounting with smb2/smb3 (e.g. vers=2.1) and cifsacl mount option,
it was trying to get the mode by querying the acl over the cifs
rather than smb2 protocol.  This patch makes that protocol
independent and makes cifsacl smb2 mounts return a more intuitive
operation not supported error (until we add a worker function
for smb2_get_acl).

Note that a previous patch fixed getxattr/setxattr for the CIFSACL xattr
which would unconditionally call cifs_get_acl and cifs_set_acl (even when
mounted smb2). I made those protocol independent last week (new protocol
version operations "get_acl" and "set_acl" but did not add an
smb2_get_acl and smb2_set_acl yet so those now simply return EOPNOTSUPP
which at least is better than sending cifs requests on smb2 mount)

The previous patches did not fix the one remaining case though ie
mounting with "cifsacl" when getting mode from acl would unconditionally
end up calling "cifs_get_acl_from_fid" even for smb2 - so made that protocol
independent but to make that protocol independent had to make sure that the callers
were passing the protocol independent handle structure (cifs_fid) instead
of cifs specific _u16 network file handle (ie cifs_fid instead of cifs_fid->fid)

Now mount with smb2 and cifsacl mount options will return EOPNOTSUP (instead
of timing out) and a future patch will add smb2 operations (e.g. get_smb2_acl)
to enable this.

Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 24 insertions, 9 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index c819b0b..7ff866d 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -865,8 +865,8 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
 	return rc;
 }
 
-static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
-		__u16 fid, u32 *pacllen)
+struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
+		const struct cifs_fid *cifsfid, u32 *pacllen)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	unsigned int xid;
@@ -877,7 +877,8 @@ static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
 		return ERR_CAST(tlink);
 
 	xid = get_xid();
-	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen);
+	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), cifsfid->netfid, &pntsd,
+				pacllen);
 	free_xid(xid);
 
 	cifs_put_tlink(tlink);
@@ -946,7 +947,7 @@ struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
 	if (!open_file)
 		return get_cifs_acl_by_path(cifs_sb, path, pacllen);
 
-	pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->fid.netfid, pacllen);
+	pntsd = get_cifs_acl_by_fid(cifs_sb, &open_file->fid, pacllen);
 	cifsFileInfo_put(open_file);
 	return pntsd;
 }
@@ -1006,19 +1007,31 @@ out:
 /* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
 int
 cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
-		  struct inode *inode, const char *path, const __u16 *pfid)
+		  struct inode *inode, const char *path,
+		  const struct cifs_fid *pfid)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	u32 acllen = 0;
 	int rc = 0;
+	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+	struct cifs_tcon *tcon;
 
 	cifs_dbg(NOISY, "converting ACL to mode for %s\n", path);
 
-	if (pfid)
-		pntsd = get_cifs_acl_by_fid(cifs_sb, *pfid, &acllen);
-	else
-		pntsd = get_cifs_acl(cifs_sb, inode, path, &acllen);
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+	tcon = tlink_tcon(tlink);
 
+	if (pfid && (tcon->ses->server->ops->get_acl_by_fid))
+		pntsd = tcon->ses->server->ops->get_acl_by_fid(cifs_sb, pfid,
+							  &acllen);
+	else if (tcon->ses->server->ops->get_acl)
+		pntsd = tcon->ses->server->ops->get_acl(cifs_sb, inode, path,
+							&acllen);
+	else {
+		cifs_put_tlink(tlink);
+		return -EOPNOTSUPP;
+	}
 	/* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
 	if (IS_ERR(pntsd)) {
 		rc = PTR_ERR(pntsd);
@@ -1030,6 +1043,8 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
 			cifs_dbg(VFS, "parse sec desc failed rc = %d\n", rc);
 	}
 
+	cifs_put_tlink(tlink);
+
 	return rc;
 }