cifs: Check uniqueid for SMB2+ and return -ESTALE if necessary

Commit 7196ac1 ("Fix to check Unique id and FileType when client refer file directly.") checks whether the uniqueid of an inode has changed when getting the inode info, but only when using the UNIX extensions. Add a similar check for SMB2+, since this can be done without an extra network roundtrip. Signed-off-by: Ross Lagerwall <[email protected]> Signed-off-by: Steve French <[email protected]>
kyagi · Jan 14, 2016 · a108471 · a108471
1 parent 275516c
commit a108471
Showing 1 changed file with 22 additions and 2 deletions.
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
@@ -814,8 +814,21 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
 			}
 		} else
 			fattr.cf_uniqueid = iunique(sb, ROOT_I);
-	} else
-		fattr.cf_uniqueid = CIFS_I(*inode)->uniqueid;
+	} else {
+		if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) &&
+		    validinum == false && server->ops->get_srv_inum) {
+			/*
+			 * Pass a NULL tcon to ensure we don't make a round
+			 * trip to the server. This only works for SMB2+.
+			 */
+			tmprc = server->ops->get_srv_inum(xid,
+				NULL, cifs_sb, full_path,
+				&fattr.cf_uniqueid, data);
+			if (tmprc)
+				fattr.cf_uniqueid = CIFS_I(*inode)->uniqueid;
+		} else
+			fattr.cf_uniqueid = CIFS_I(*inode)->uniqueid;
+	}
 
 	/* query for SFU type info if supported and needed */
 	if (fattr.cf_cifsattrs & ATTR_SYSTEM &&
@@ -856,6 +869,13 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
 	} else {
 		/* we already have inode, update it */
 
+		/* if uniqueid is different, return error */
+		if (unlikely(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM &&
+		    CIFS_I(*inode)->uniqueid != fattr.cf_uniqueid)) {
+			rc = -ESTALE;
+			goto cgii_exit;
+		}
+
 		/* if filetype is different, return error */
 		if (unlikely(((*inode)->i_mode & S_IFMT) !=
 		    (fattr.cf_mode & S_IFMT))) {