2 files changed, 37 insertions, 3 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 1f17f6bd7a60..3e95191fcb95 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -525,6 +525,7 @@ struct smb_vol {
         struct sockaddr_storage srcaddr; /* allow binding to a local IP */
         struct nls_table *local_nls;
         unsigned int echo_interval; /* echo interval in secs */
+        __u64 snapshot_time; /* needed for timewarp tokens */
         unsigned int max_credits; /* smb3 max_credits 10 < credits < 60000 */
 };
 
@@ -932,6 +933,7 @@ struct cifs_tcon {
         __u32 maximal_access;
         __u32 vol_serial_number;
         __le64 vol_create_time;
+        __u64 snapshot_time; /* for timewarp tokens - timestamp of snapshot */
         __u32 ss_flags;         /* sector size flags */
         __u32 perf_sector_size; /* best sector size for perf */
         __u32 max_chunks;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 4547aeddd12b..5563de3c64fd 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -95,6 +95,7 @@ enum {
         Opt_dirmode, Opt_port,
         Opt_rsize, Opt_wsize, Opt_actimeo,
         Opt_echo_interval, Opt_max_credits,
+        Opt_snapshot,
 
         /* Mount options which take string value */
         Opt_user, Opt_pass, Opt_ip,
@@ -191,6 +192,7 @@ static const match_table_t cifs_mount_option_tokens = {
         { Opt_actimeo, "actimeo=%s" },
         { Opt_echo_interval, "echo_interval=%s" },
         { Opt_max_credits, "max_credits=%s" },
+        { Opt_snapshot, "snapshot=%s" },
 
         { Opt_blank_user, "user=" },
         { Opt_blank_user, "username=" },
@@ -1601,6 +1603,14 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
                         }
                         vol->echo_interval = option;
                         break;
+                case Opt_snapshot:
+                        if (get_option_ul(args, &option)) {
+                                cifs_dbg(VFS, "%s: Invalid snapshot time\n",
+                                         __func__);
+                                goto cifs_parse_mount_err;
+                        }
+                        vol->snapshot_time = option;
+                        break;
                 case Opt_max_credits:
                         if (get_option_ul(args, &option) || (option < 20) ||
                             (option > 60000)) {
@@ -2586,7 +2596,7 @@ static int match_tcon(struct cifs_tcon *tcon, const char *unc)
 }
 
 static struct cifs_tcon *
-cifs_find_tcon(struct cifs_ses *ses, const char *unc)
+cifs_find_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
 {
         struct list_head *tmp;
         struct cifs_tcon *tcon;
@@ -2594,8 +2604,14 @@ cifs_find_tcon(struct cifs_ses *ses, const char *unc)
         spin_lock(&cifs_tcp_ses_lock);
         list_for_each(tmp, &ses->tcon_list) {
                 tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
-                if (!match_tcon(tcon, unc))
+                if (!match_tcon(tcon, volume_info->UNC))
                         continue;
+
+#ifdef CONFIG_CIFS_SMB2
+                if (tcon->snapshot_time != volume_info->snapshot_time)
+                        continue;
+#endif /* CONFIG_CIFS_SMB2 */
+
                 ++tcon->tc_count;
                 spin_unlock(&cifs_tcp_ses_lock);
                 return tcon;
@@ -2636,7 +2652,7 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
         int rc, xid;
         struct cifs_tcon *tcon;
 
-        tcon = cifs_find_tcon(ses, volume_info->UNC);
+        tcon = cifs_find_tcon(ses, volume_info);
         if (tcon) {
                 cifs_dbg(FYI, "Found match on UNC path\n");
                 /* existing tcon already has a reference */
@@ -2657,6 +2673,22 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
                 goto out_fail;
         }
 
+        if (volume_info->snapshot_time) {
+#ifdef CONFIG_CIFS_SMB2
+                if (ses->server->vals->protocol_id == 0) {
+                        cifs_dbg(VFS,
+                             "Use SMB2 or later for snapshot mount option\n");
+                        rc = -EOPNOTSUPP;
+                        goto out_fail;
+                } else
+                        tcon->snapshot_time = volume_info->snapshot_time;
+#else
+                cifs_dbg(VFS, "Snapshot mount option requires SMB2 support\n");
+                rc = -EOPNOTSUPP;
+                goto out_fail;
+#endif /* CONFIG_CIFS_SMB2 */
+        }
+
         tcon->ses = ses;
         if (volume_info->password) {
                 tcon->password = kstrdup(volume_info->password, GFP_KERNEL);