cifs: handle prefix paths in reconnect
For the case where we have a DFS path like below and we're currently
connected to targetA:
//dfsroot/link -> //targetA/share/foo, //targetB/share/bar
after failover, we should make sure to update cifs_sb->prepath so the
next operations will use the new prefix path "/bar".
Besides, in order to simplify the use of different prefix paths,
enforce CIFS_MOUNT_USE_PREFIX_PATH for DFS mounts so we don't have to
revalidate the root dentry every time we set a new prefix path.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 28c0be5e..8c23c10 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -193,9 +193,18 @@ static int __smb2_reconnect(const struct nls_table *nlsc,
for (it = dfs_cache_get_tgt_iterator(&tl); it;
it = dfs_cache_get_next_tgt(&tl, it)) {
- const char *tgt = dfs_cache_get_tgt_name(it);
+ const char *share, *prefix;
+ size_t share_len, prefix_len;
- extract_unc_hostname(tgt, &dfs_host, &dfs_host_len);
+ rc = dfs_cache_get_tgt_share(it, &share, &share_len, &prefix,
+ &prefix_len);
+ if (rc) {
+ cifs_dbg(VFS, "%s: failed to parse target share %d\n",
+ __func__, rc);
+ continue;
+ }
+
+ extract_unc_hostname(share, &dfs_host, &dfs_host_len);
if (dfs_host_len != tcp_host_len
|| strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
@@ -206,11 +215,13 @@ static int __smb2_reconnect(const struct nls_table *nlsc,
continue;
}
- scnprintf(tree, MAX_TREE_SIZE, "\\%s", tgt);
+ scnprintf(tree, MAX_TREE_SIZE, "\\%.*s", (int)share_len, share);
rc = SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
- if (!rc)
+ if (!rc) {
+ rc = update_super_prepath(tcon, prefix, prefix_len);
break;
+ }
if (rc == -EREMOTE)
break;
}