#include "cifs_debug.h"
#include "cifs_unicode.h"
#include "smb2glob.h"
+#include "dns_resolve.h"
#include "dfs_cache.h"
err_free_it:
list_for_each_entry_safe(it, nit, head, it_list) {
+ list_del(&it->it_list);
kfree(it->it_name);
kfree(it);
}
return 0;
}
+static bool target_share_equal(struct TCP_Server_Info *server, const char *s1, const char *s2)
+{
+ char unc[sizeof("\\\\") + SERVER_NAME_LENGTH] = {0};
+ const char *host;
+ size_t hostlen;
+ char *ip = NULL;
+ struct sockaddr sa;
+ bool match;
+ int rc;
+
+ if (strcasecmp(s1, s2))
+ return false;
+
+ /*
+ * Resolve share's hostname and check if server address matches. Otherwise just ignore it
+ * as we could not have upcall to resolve hostname or failed to convert ip address.
+ */
+ match = true;
+ extract_unc_hostname(s1, &host, &hostlen);
+ scnprintf(unc, sizeof(unc), "\\\\%.*s", (int)hostlen, host);
+
+ rc = dns_resolve_server_name_to_ip(unc, &ip, NULL);
+ if (rc < 0) {
+ cifs_dbg(FYI, "%s: could not resolve %.*s. assuming server address matches.\n",
+ __func__, (int)hostlen, host);
+ return true;
+ }
+
+ if (!cifs_convert_address(&sa, ip, strlen(ip))) {
+ cifs_dbg(VFS, "%s: failed to convert address \'%s\'. skip address matching.\n",
+ __func__, ip);
+ } else {
+ mutex_lock(&server->srv_mutex);
+ match = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, &sa);
+ mutex_unlock(&server->srv_mutex);
+ }
+
+ kfree(ip);
+ return match;
+}
+
+/*
+ * Mark dfs tcon for reconnecting when the currently connected tcon does not match any of the new
+ * target shares in @refs.
+ */
+static void mark_for_reconnect_if_needed(struct cifs_tcon *tcon, struct dfs_cache_tgt_list *tl,
+ const struct dfs_info3_param *refs, int numrefs)
+{
+ struct dfs_cache_tgt_iterator *it;
+ int i;
+
+ for (it = dfs_cache_get_tgt_iterator(tl); it; it = dfs_cache_get_next_tgt(tl, it)) {
+ for (i = 0; i < numrefs; i++) {
+ if (target_share_equal(tcon->ses->server, dfs_cache_get_tgt_name(it),
+ refs[i].node_name))
+ return;
+ }
+ }
+
+ cifs_dbg(FYI, "%s: no cached or matched targets. mark dfs share for reconnect.\n", __func__);
+ for (i = 0; i < tcon->ses->chan_count; i++) {
+ spin_lock(&GlobalMid_Lock);
+ if (tcon->ses->chans[i].server->tcpStatus != CifsExiting)
+ tcon->ses->chans[i].server->tcpStatus = CifsNeedReconnect;
+ spin_unlock(&GlobalMid_Lock);
+ }
+}
+
+/* Refresh dfs referral of tcon and mark it for reconnect if needed */
+static int refresh_tcon(struct cifs_ses **sessions, struct cifs_tcon *tcon, bool force_refresh)
+{
+ const char *path = tcon->dfs_path + 1;
+ struct cifs_ses *ses;
+ struct cache_entry *ce;
+ struct dfs_info3_param *refs = NULL;
+ int numrefs = 0;
+ bool needs_refresh = false;
+ struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
+ int rc = 0;
+ unsigned int xid;
+
+ ses = find_ipc_from_server_path(sessions, path);
+ if (IS_ERR(ses)) {
+ cifs_dbg(FYI, "%s: could not find ipc session\n", __func__);
+ return PTR_ERR(ses);
+ }
+
+ down_read(&htable_rw_lock);
+ ce = lookup_cache_entry(path);
+ needs_refresh = force_refresh || IS_ERR(ce) || cache_entry_expired(ce);
+ if (!IS_ERR(ce)) {
+ rc = get_targets(ce, &tl);
+ if (rc)
+ cifs_dbg(FYI, "%s: could not get dfs targets: %d\n", __func__, rc);
+ }
+ up_read(&htable_rw_lock);
+
+ if (!needs_refresh) {
+ rc = 0;
+ goto out;
+ }
+
+ xid = get_xid();
+ rc = get_dfs_referral(xid, ses, path, &refs, &numrefs);
+ free_xid(xid);
+
+ /* Create or update a cache entry with the new referral */
+ if (!rc) {
+ dump_refs(refs, numrefs);
+
+ down_write(&htable_rw_lock);
+ ce = lookup_cache_entry(path);
+ if (IS_ERR(ce))
+ add_cache_entry_locked(refs, numrefs);
+ else if (force_refresh || cache_entry_expired(ce))
+ update_cache_entry_locked(ce, refs, numrefs);
+ up_write(&htable_rw_lock);
+
+ mark_for_reconnect_if_needed(tcon, &tl, refs, numrefs);
+ }
+
+out:
+ dfs_cache_free_tgts(&tl);
+ free_dfs_info_array(refs, numrefs);
+ return rc;
+}
+
+/**
+ * dfs_cache_remount_fs - remount a DFS share
+ *
+ * Reconfigure dfs mount by forcing a new DFS referral and if the currently cached targets do not
+ * match any of the new targets, mark it for reconnect.
+ *
+ * @cifs_sb: cifs superblock.
+ *
+ * Return zero if remounted, otherwise non-zero.
+ */
+int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb)
+{
+ struct cifs_tcon *tcon;
+ struct mount_group *mg;
+ struct cifs_ses *sessions[CACHE_MAX_ENTRIES + 1] = {NULL};
+ int rc;
+
+ if (!cifs_sb || !cifs_sb->master_tlink)
+ return -EINVAL;
+
+ tcon = cifs_sb_master_tcon(cifs_sb);
+ if (!tcon->dfs_path) {
+ cifs_dbg(FYI, "%s: not a dfs tcon\n", __func__);
+ return 0;
+ }
+
+ if (uuid_is_null(&cifs_sb->dfs_mount_id)) {
+ cifs_dbg(FYI, "%s: tcon has no dfs mount group id\n", __func__);
+ return -EINVAL;
+ }
+
+ mutex_lock(&mount_group_list_lock);
+ mg = find_mount_group_locked(&cifs_sb->dfs_mount_id);
+ if (IS_ERR(mg)) {
+ mutex_unlock(&mount_group_list_lock);
+ cifs_dbg(FYI, "%s: tcon has ipc session to refresh referral\n", __func__);
+ return PTR_ERR(mg);
+ }
+ kref_get(&mg->refcount);
+ mutex_unlock(&mount_group_list_lock);
+
+ spin_lock(&mg->lock);
+ memcpy(&sessions, mg->sessions, mg->num_sessions * sizeof(mg->sessions[0]));
+ spin_unlock(&mg->lock);
+
+ /*
+ * After reconnecting to a different server, unique ids won't match anymore, so we disable
+ * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
+ */
+ cifs_autodisable_serverino(cifs_sb);
+ /*
+ * Force the use of prefix path to support failover on DFS paths that resolve to targets
+ * that have different prefix paths.
+ */
+ cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
+ rc = refresh_tcon(sessions, tcon, true);
+
+ kref_put(&mg->refcount, mount_group_release);
+ return rc;
+}
+
/*
* Refresh all active dfs mounts regardless of whether they are in cache or not.
* (cache can be cleared)
struct cifs_ses *ses;
struct cifs_tcon *tcon, *ntcon;
struct list_head tcons;
- unsigned int xid;
INIT_LIST_HEAD(&tcons);
spin_unlock(&cifs_tcp_ses_lock);
list_for_each_entry_safe(tcon, ntcon, &tcons, ulist) {
- const char *path = tcon->dfs_path + 1;
- struct cache_entry *ce;
- struct dfs_info3_param *refs = NULL;
- int numrefs = 0;
- bool needs_refresh = false;
- int rc = 0;
-
list_del_init(&tcon->ulist);
-
- ses = find_ipc_from_server_path(sessions, path);
- if (IS_ERR(ses))
- goto next_tcon;
-
- down_read(&htable_rw_lock);
- ce = lookup_cache_entry(path);
- needs_refresh = IS_ERR(ce) || cache_entry_expired(ce);
- up_read(&htable_rw_lock);
-
- if (!needs_refresh)
- goto next_tcon;
-
- xid = get_xid();
- rc = get_dfs_referral(xid, ses, path, &refs, &numrefs);
- free_xid(xid);
-
- /* Create or update a cache entry with the new referral */
- if (!rc) {
- down_write(&htable_rw_lock);
- ce = lookup_cache_entry(path);
- if (IS_ERR(ce))
- add_cache_entry_locked(refs, numrefs);
- else if (cache_entry_expired(ce))
- update_cache_entry_locked(ce, refs, numrefs);
- up_write(&htable_rw_lock);
- }
-
-next_tcon:
- free_dfs_info_array(refs, numrefs);
+ refresh_tcon(sessions, tcon, false);
cifs_put_tcon(tcon);
}
}
projects / linux-2.6-microblaze.git / blobdiff