glusterd/snapshot: Inherit the mount options of a original brick

when creating snapshots

When creating a snapshot a LVM is created at the backend and is mounted
under /var/run/gluster/snaps/... However, this mount does not inherit
the mount options for the original brick acting as the parent for the
snap.

If the snap is restored, this could lead to performance degredations,
functional limitations, or in extreme scenarios even potential data
loss.

Change-Id: I67d70fd83430d83dacc5380c6c928e27fb9c9e1b
BUG: 1125180
Signed-off-by: Vijaikumar M <vmallika@redhat.com>
Reviewed-on: http://review.gluster.org/8394
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>

1 files changed, 103 insertions, 15 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index 14d98c544aa..ee3759e91d4 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -595,6 +595,7 @@ glusterd_brickinfo_dup (glusterd_brickinfo_t *brickinfo,
         strcpy (dup_brickinfo->path, brickinfo->path);
         strcpy (dup_brickinfo->device_path, brickinfo->device_path);
         strcpy (dup_brickinfo->fstype, brickinfo->fstype);
+        strcpy (dup_brickinfo->mnt_opts, brickinfo->mnt_opts);
         ret = gf_canonicalize_path (dup_brickinfo->path);
         if (ret) {
                 gf_log (THIS->name, GF_LOG_ERROR, "Failed to canonicalize "
@@ -700,6 +701,13 @@ glusterd_snap_volinfo_restore (dict_t *dict, dict_t *rsp_dict,
                         strncpy (new_brickinfo->fstype, value,
                                  sizeof(new_brickinfo->fstype));
 
+                snprintf (key, sizeof (key), "snap%d.brick%d.mnt_opts",
+                          volcount, brick_count);
+                ret = dict_get_str (dict, key, &value);
+                if (!ret)
+                        strncpy (new_brickinfo->mnt_opts, value,
+                                 sizeof(new_brickinfo->mnt_opts));
+
                 /* If the brick is not of this peer, or snapshot is missed *
                  * for the brick do not replace the xattr for it */
                 if ((!uuid_compare (brickinfo->uuid, MY_UUID)) &&
@@ -2304,6 +2312,15 @@ gd_add_brick_snap_details_to_dict (dict_t *dict, char *prefix,
                 goto out;
         }
 
+        snprintf (key, sizeof (key), "%s.mnt_opts", prefix);
+        ret = dict_set_str (dict, key, brickinfo->mnt_opts);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "Failed to set mnt_opts for %s:%s",
+                         brickinfo->hostname, brickinfo->path);
+                goto out;
+        }
+
         memset (key, 0, sizeof (key));
         snprintf (key, sizeof (key), "%s.mount_dir", prefix);
         ret = dict_set_str (dict, key, brickinfo->mount_dir);
@@ -3657,6 +3674,7 @@ gd_import_new_brick_snap_details (dict_t *dict, char *prefix,
         char             key[512]    = {0,};
         char            *snap_device = NULL;
         char            *fs_type     = NULL;
+        char            *mnt_opts    = NULL;
         char            *mount_dir   = NULL;
 
         this = THIS;
@@ -3697,6 +3715,14 @@ gd_import_new_brick_snap_details (dict_t *dict, char *prefix,
         }
         strcpy (brickinfo->fstype, fs_type);
 
+        snprintf (key, sizeof (key), "%s.mnt_opts", prefix);
+        ret = dict_get_str (dict, key, &mnt_opts);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "%s missing in payload", key);
+                goto out;
+        }
+        strcpy (brickinfo->mnt_opts, mnt_opts);
+
         memset (key, 0, sizeof (key));
         snprintf (key, sizeof (key), "%s.mount_dir", prefix);
         ret = dict_get_str (dict, key, &mount_dir);
@@ -11901,34 +11927,44 @@ glusterd_compare_volume_name(struct list_head *list1, struct list_head *list2)
 }
 
 int32_t
-glusterd_mount_lvm_snapshot (char *device_path, char *brick_mount_path,
-                             const char *fstype)
+glusterd_mount_lvm_snapshot (glusterd_brickinfo_t *brickinfo,
+                             char *brick_mount_path)
 {
-        char               msg[NAME_MAX] = "";
-        int32_t            ret           = -1;
-        runner_t           runner        = {0, };
-        xlator_t          *this          = NULL;
+        char               msg[NAME_MAX]  = "";
+        char               mnt_opts[1024] = "";
+        int32_t            ret            = -1;
+        runner_t           runner         = {0, };
+        xlator_t          *this           = NULL;
 
         this = THIS;
         GF_ASSERT (this);
         GF_ASSERT (brick_mount_path);
-        GF_ASSERT (device_path);
+        GF_ASSERT (brickinfo);
 
 
         runinit (&runner);
         snprintf (msg, sizeof (msg), "mount %s %s",
-                  device_path, brick_mount_path);
+                  brickinfo->device_path, brick_mount_path);
+
+        strcpy (mnt_opts, brickinfo->mnt_opts);
 
         /* XFS file-system does not allow to mount file-system with duplicate
          * UUID. File-system UUID of snapshot and its origin volume is same.
          * Therefore to mount such a snapshot in XFS we need to pass nouuid
          * option
          */
-        if (!strcmp (fstype, "xfs")) {
-                runner_add_args (&runner, "mount", "-o", "nouuid",
-                                 device_path, brick_mount_path, NULL);
+        if (!strcmp (brickinfo->fstype, "xfs")) {
+                if ( strlen (mnt_opts) > 0 )
+                        strcat (mnt_opts, ",");
+                strcat (mnt_opts, "nouuid");
+        }
+
+
+        if ( strlen (mnt_opts) > 0 ) {
+                runner_add_args (&runner, "mount", "-o", mnt_opts,
+                                brickinfo->device_path, brick_mount_path, NULL);
         } else {
-                runner_add_args (&runner, "mount", device_path,
+                runner_add_args (&runner, "mount", brickinfo->device_path,
                                  brick_mount_path, NULL);
         }
 
@@ -11936,12 +11972,12 @@ glusterd_mount_lvm_snapshot (char *device_path, char *brick_mount_path,
         ret = runner_run (&runner);
         if (ret) {
                 gf_log (this->name, GF_LOG_ERROR, "mounting the snapshot "
-                        "logical device %s failed (error: %s)", device_path,
-                        strerror (errno));
+                        "logical device %s failed (error: %s)",
+                        brickinfo->device_path, strerror (errno));
                 goto out;
         } else
                 gf_log (this->name, GF_LOG_DEBUG, "mounting the snapshot "
-                        "logical device %s successful", device_path);
+                        "logical device %s successful", brickinfo->device_path);
 
 out:
         gf_log (this->name, GF_LOG_TRACE, "Returning with %d", ret);
@@ -13398,3 +13434,55 @@ gd_get_snap_conf_values_if_present (dict_t *dict, uint64_t *sys_hard_limit,
                         GLUSTERD_STORE_KEY_SNAP_MAX_SOFT_LIMIT);
         }
 }
+
+/* This function will update the backend file-system
+ * type and the mount options in origin and snap brickinfo.
+ * This will be later used to perform file-system specific operation
+ * during LVM snapshot.
+ *
+ * @param brick_path       brickpath for which fstype to be found
+ * @param brickinfo        brickinfo of snap/origin volume
+ * @return 0 on success and -1 on failure
+ */
+int
+glusterd_update_mntopts (char *brick_path, glusterd_brickinfo_t *brickinfo)
+{
+        int32_t               ret               = -1;
+        char                 *mnt_pt            = NULL;
+        char                  buff [PATH_MAX]   = "";
+        char                  msg [PATH_MAX]    = "";
+        char                 *cmd               = NULL;
+        struct mntent        *entry             = NULL;
+        struct mntent         save_entry        = {0,};
+        runner_t              runner            = {0,};
+        xlator_t             *this              = NULL;
+
+        this = THIS;
+        GF_ASSERT (this);
+        GF_ASSERT (brick_path);
+        GF_ASSERT (brickinfo);
+
+        ret = glusterd_get_brick_root (brick_path, &mnt_pt);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "getting the root "
+                        "of the brick (%s) failed ", brick_path);
+                goto out;
+        }
+
+        entry = glusterd_get_mnt_entry_info (mnt_pt, buff, sizeof (buff),
+                                             &save_entry);
+        if (!entry) {
+                gf_log (this->name, GF_LOG_ERROR, "getting the mount entry for "
+                        "the brick (%s) failed", brick_path);
+                ret = -1;
+                goto out;
+        }
+
+        strcpy (brickinfo->fstype, entry->mnt_type);
+        strcpy (brickinfo->mnt_opts, entry->mnt_opts);
+
+        ret = 0;
+out:
+        GF_FREE (mnt_pt);
+        return ret;
+}