snapshot : copying nfs-ganesha export file

Backport of http://review.gluster.org/#/c/12483/

While taking snapshot, the export file used by the volume should
copy to snap directory. So that when restore of snapshot happens,
the volume can retain all its configuration for exporting via
nfs-ganesha. The export file is stored at "/etc/ganesha/export" in
the following format "export.<volname>.conf"

The fix handles given cases in the following manner :

case a: The nfs-ganesha(global) is ON during snapshot and restore.
        i.) Volume was exported during snapshot. When we restore snapshot,
            then volume should be exported back with old configuration file.
        ii.) Volume was unexported during snapshot. When we restore snapshot,
             then volume should unexported again.

case b: The nfs-ganesha is ON during snapshot and OFF during restore
        Volume was exported during snapshot. When we restore snapshot, the
        conf will be copied to corresponding location and if nfs-ganesha enabled
        again, then volume will be exported.

For the clones, export conf file will created in /etc/ganesha/export and then
export it via ganesha.

Upstream Reference:

(cherry picked from commit 5583bac79851d24f0a552478b361049fe63c32b7)
>Change-Id: Ideecda15bd4db58e991cf6c8de7bb93f3db6cd20
>BUG: 1257709
>Signed-off-by: Jiffin Tony Thottan <jthottan@redhat.com>
>Reviewed-on: http://review.gluster.org/12034
>Reviewed-by: Avra Sengupta <asengupt@redhat.com>
>Tested-by: Gluster Build System <jenkins@build.gluster.com>
>Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>

Change-Id: I19725ec3d093fb32067bba4aba7f5bc3fd61b0e3
BUG: 1257710
Signed-off-by: Jiffin Tony Thottan <jthottan@redhat.com>
Reviewed-on: http://review.gluster.org/12483
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Avra Sengupta <asengupt@redhat.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>

1 files changed, 185 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c b/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c
index 39f21678853..aba6c85028e 100644
--- a/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c
@@ -3492,6 +3492,135 @@ out:
 
 }
 
+/* *
+ * Here there are two possibilities, either destination is snaphot or
+ * clone. In the case of snapshot nfs_ganesha export file will be copied
+ * to snapdir. If it is clone , then new export file will be created for
+ * the clone in the GANESHA_EXPORT_DIRECTORY, replacing occurences of
+ * volname with clonename
+ */
+int
+glusterd_copy_nfs_ganesha_file (glusterd_volinfo_t *src_vol,
+                                glusterd_volinfo_t *dest_vol)
+{
+
+        int32_t         ret                     = -1;
+        char            snap_dir[PATH_MAX]      = "";
+        char            src_path[PATH_MAX]      = "";
+        char            dest_path[PATH_MAX]     = "";
+        char            buffer[BUFSIZ]          = "";
+        char            *find_ptr               = NULL;
+        char            *buff_ptr               = NULL;
+        char            *tmp_ptr                = NULL;
+        xlator_t        *this                   = NULL;
+        glusterd_conf_t *priv                   = NULL;
+        struct  stat    stbuf                   = {0,};
+        FILE            *src                    = NULL;
+        FILE            *dest                   = NULL;
+
+
+        this = THIS;
+        GF_VALIDATE_OR_GOTO ("snapshot", this, out);
+        priv = this->private;
+        GF_VALIDATE_OR_GOTO (this->name, priv, out);
+
+        GF_VALIDATE_OR_GOTO (this->name, src_vol, out);
+        GF_VALIDATE_OR_GOTO (this->name, dest_vol, out);
+
+        if (src_vol->is_snap_volume) {
+                GLUSTERD_GET_SNAP_DIR (snap_dir, src_vol->snapshot, priv);
+                ret = snprintf (src_path, sizeof (src_path),
+                                "%s/export.%s.conf", snap_dir,
+                                src_vol->snapshot->snapname);
+        } else {
+                ret = snprintf (src_path, sizeof (src_path),
+                                "%s/export.%s.conf", GANESHA_EXPORT_DIRECTORY,
+                                src_vol->volname);
+                if (ret < 0)
+                        goto out;
+        }
+
+        ret = lstat (src_path, &stbuf);
+        if (ret) {
+                /* *
+                * If export file is not present, volume is not exported
+                * via ganesha. So it is not necessary to copy that during
+                * snapshot.
+                */
+                if (errno == ENOENT) {
+                        ret = 0;
+                        gf_msg_debug (this->name, 0, "%s not found", src_path);
+                } else
+                        gf_msg (this->name, GF_LOG_WARNING, errno,
+                                GD_MSG_FILE_OP_FAILED,
+                                "Stat on %s failed with %s",
+                                src_path, strerror (errno));
+                goto out;
+        }
+
+        if (dest_vol->is_snap_volume) {
+                memset (snap_dir, 0 , PATH_MAX);
+                GLUSTERD_GET_SNAP_DIR (snap_dir, dest_vol->snapshot, priv);
+                ret = snprintf (dest_path, sizeof (dest_path),
+                                "%s/export.%s.conf", snap_dir,
+                                dest_vol->snapshot->snapname);
+                if (ret < 0)
+                        goto out;
+
+                ret = glusterd_copy_file (src_path, dest_path);
+                if (ret) {
+                        gf_msg (this->name, GF_LOG_ERROR, ENOMEM,
+                                GD_MSG_NO_MEMORY, "Failed to copy %s in %s",
+                                src_path, dest_path);
+                        goto out;
+                }
+
+        } else {
+                ret = snprintf (dest_path, sizeof (dest_path),
+                                "%s/export.%s.conf", GANESHA_EXPORT_DIRECTORY,
+                                dest_vol->volname);
+                if (ret < 0)
+                        goto out;
+
+                src = fopen (src_path, "r");
+                dest = fopen (dest_path, "w");
+
+                /* *
+                 * if the source volume is snapshot, the export conf file
+                 * consists of orginal volname
+                 */
+                if (src_vol->is_snap_volume)
+                        find_ptr = gf_strdup (src_vol->parent_volname);
+                else
+                        find_ptr = gf_strdup (src_vol->volname);
+
+                if (!find_ptr)
+                        goto out;
+
+                /* Replacing volname with clonename */
+                while (fgets(buffer, BUFSIZ, src)) {
+                        buff_ptr = buffer;
+                        while ((tmp_ptr = strstr(buff_ptr, find_ptr))) {
+                                while (buff_ptr < tmp_ptr)
+                                        fputc((int)*buff_ptr++, dest);
+                                fputs(dest_vol->volname, dest);
+                                buff_ptr += strlen(find_ptr);
+                        }
+                        fputs(buff_ptr, dest);
+                        memset (buffer, 0, BUFSIZ);
+                }
+        }
+out:
+        if (src)
+                fclose (src);
+        if (dest)
+                fclose (dest);
+        if (find_ptr)
+                GF_FREE(find_ptr);
+
+        return ret;
+}
+
 int32_t
 glusterd_restore_geo_rep_files (glusterd_volinfo_t *snap_vol)
 {
@@ -3582,6 +3711,62 @@ out:
         return ret;
 }
 
+int
+glusterd_restore_nfs_ganesha_file (glusterd_volinfo_t *src_vol,
+                                   glusterd_snap_t *snap)
+{
+
+        int32_t         ret                     = -1;
+        char            snap_dir[PATH_MAX]      = "";
+        char            src_path[PATH_MAX]      = "";
+        char            dest_path[PATH_MAX]     = "";
+        xlator_t        *this                   = NULL;
+        glusterd_conf_t *priv                   = NULL;
+        struct  stat    stbuf                   = {0,};
+
+        this = THIS;
+        GF_VALIDATE_OR_GOTO ("snapshot", this, out);
+        priv = this->private;
+        GF_VALIDATE_OR_GOTO (this->name, priv, out);
+
+        GF_VALIDATE_OR_GOTO (this->name, src_vol, out);
+        GF_VALIDATE_OR_GOTO (this->name, snap, out);
+
+        GLUSTERD_GET_SNAP_DIR (snap_dir, snap, priv);
+
+        ret = snprintf (src_path, sizeof (src_path), "%s/export.%s.conf",
+                       snap_dir, snap->snapname);
+        if (ret < 0)
+                goto out;
+
+        ret = lstat (src_path, &stbuf);
+        if (ret) {
+                if (errno == ENOENT) {
+                        ret = 0;
+                        gf_msg_debug (this->name, 0, "%s not found", src_path);
+                } else
+                        gf_msg (this->name, GF_LOG_WARNING, errno,
+                                GD_MSG_FILE_OP_FAILED,
+                                "Stat on %s failed with %s",
+                                src_path, strerror (errno));
+                goto out;
+        }
+
+        ret = snprintf (dest_path, sizeof (dest_path), "%s/export.%s.conf",
+                        GANESHA_EXPORT_DIRECTORY, src_vol->volname);
+        if (ret < 0)
+                goto out;
+
+        ret = glusterd_copy_file (src_path, dest_path);
+        if (ret)
+                gf_msg (this->name, GF_LOG_ERROR, ENOMEM,
+                        GD_MSG_NO_MEMORY, "Failed to copy %s in %s",
+                        src_path, dest_path);
+
+out:
+        return ret;
+
+}
 /* Snapd functions */
 int
 glusterd_is_snapd_enabled (glusterd_volinfo_t *volinfo)