glusterd : Introduce reset brick

The command basically allows replace brick with src and
dst bricks as same.

Usage:
gluster v reset-brick <volname> <hostname:brick-path> start
This command kills the brick to be reset. Once this command is run,
admin can do other manual operations that they need to do,
like configuring some options for the brick. Once this is done,
resetting the brick can be continued with the following options.

gluster v reset-brick <vname> <hostname:brick> <hostname:brick> commit {force}

Does the job of resetting the brick. 'force' option should be used
when the brick already contains volinfo id.

Problem: On doing a disk-replacement of a brick in a replicate volume
the following 2 scenarios may occur :

a) there is a chance that reads are served from this replaced-disk brick,
which leads to empty reads. b) potential data loss if next writes succeed
only on replaced brick, and heal is done to other bricks from this one.

Solution: After disk-replacement, make sure that reset-brick command is
run for that brick so that pending markers are set for the brick and it
is not chosen as source for reads and heal. But, as of now replace-brick
for the same brick-path is not allowed. In order to fix the above
mentioned problem, same brick-path replace-brick is needed.
With this patch reset-brick commit {force} will be allowed even when
source and destination <hostname:brickpath> are identical as long as
1) destination brick is not alive
2) source and destination brick have the same brick uuid and path.
Also, the destination brick after replace-brick will use the same port
as the source brick.

Change-Id: I440b9e892ffb781ea4b8563688c3f85c7a7c89de
BUG: 1266876
Signed-off-by: Anuradha Talur <atalur@redhat.com>
Reviewed-on: http://review.gluster.org/12250
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Ashish Pandey <aspandey@redhat.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

1 files changed, 324 insertions, 3 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index ec371d80815..0011cac0078 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -5970,7 +5970,7 @@ glusterd_is_defrag_on (glusterd_volinfo_t *volinfo)
 
 int
 glusterd_new_brick_validate (char *brick, glusterd_brickinfo_t *brickinfo,
-                             char *op_errstr, size_t len)
+                             char *op_errstr, size_t len, char *op)
 {
         glusterd_brickinfo_t    *newbrickinfo = NULL;
         int                     ret = -1;
@@ -6011,8 +6011,12 @@ glusterd_new_brick_validate (char *brick, glusterd_brickinfo_t *brickinfo,
                                                       newbrickinfo->path)) {
                         snprintf(op_errstr, len, "Brick: %s not available."
                                  " Brick may be containing or be contained "
-                                 "by an existing brick", brick);
-                        ret = -1;
+                                 "by an existing brick.", brick);
+                        if (op && (!strcmp (op, "GF_RESET_OP_COMMIT") ||
+                            !strcmp (op, "GF_RESET_OP_COMMIT_FORCE")))
+                                ret = 1;
+                        else
+                                ret = -1;
                         goto out;
                 }
 
@@ -11458,6 +11462,7 @@ glusterd_disallow_op_for_tier (glusterd_volinfo_t *volinfo, glusterd_op_t op,
         switch (op) {
         case GD_OP_ADD_BRICK:
         case GD_OP_REPLACE_BRICK:
+	case GD_OP_RESET_BRICK:
                 ret = -1;
                 gf_msg_debug (this->name, 0, "Operation not "
                         "permitted on tiered volume %s",
@@ -11708,3 +11713,319 @@ get_last_brick_of_brick_group (glusterd_volinfo_t *volinfo,
 
         return last;
 }
+
+int
+glusterd_get_rb_dst_brickinfo (glusterd_volinfo_t *volinfo,
+                               glusterd_brickinfo_t **brickinfo)
+{
+        int32_t                 ret = -1;
+
+        if (!volinfo || !brickinfo)
+                goto out;
+
+        *brickinfo = volinfo->rep_brick.dst_brick;
+
+        ret = 0;
+
+out:
+        return ret;
+}
+
+int
+rb_update_dstbrick_port (glusterd_brickinfo_t *dst_brickinfo, dict_t *rsp_dict,
+                         dict_t *req_dict)
+{
+        int     ret           = 0;
+        int     dict_ret      = 0;
+        int     dst_port      = 0;
+
+        dict_ret = dict_get_int32 (req_dict, "dst-brick-port", &dst_port);
+        if (!dict_ret)
+                dst_brickinfo->port = dst_port;
+
+        if (gf_is_local_addr (dst_brickinfo->hostname)) {
+                gf_msg ("glusterd", GF_LOG_INFO, 0,
+                        GD_MSG_BRK_PORT_NO_ADD_INDO,
+                        "adding dst-brick port no %d", dst_port);
+
+                if (rsp_dict) {
+                        ret = dict_set_int32 (rsp_dict, "dst-brick-port",
+                                              dst_brickinfo->port);
+                        if (ret) {
+                                gf_msg_debug ("glusterd", 0,
+                                        "Could not set dst-brick port no in rsp dict");
+                                goto out;
+                        }
+                }
+
+                if (req_dict && !dict_ret) {
+                        ret = dict_set_int32 (req_dict, "dst-brick-port",
+                                              dst_brickinfo->port);
+                        if (ret) {
+                                gf_msg_debug ("glusterd", 0,
+                                        "Could not set dst-brick port no");
+                                goto out;
+                        }
+                }
+        }
+out:
+        return ret;
+}
+
+int
+glusterd_brick_op_prerequisites (dict_t *dict,
+                                 char **op,
+                                 glusterd_op_t *gd_op, char **volname,
+                                 glusterd_volinfo_t **volinfo,
+                                 char **src_brick, glusterd_brickinfo_t
+                                 **src_brickinfo, char *pidfile,
+                                 char **op_errstr, dict_t *rsp_dict)
+{
+        int                                      ret                = 0;
+        char                                     msg[2048]          = {0};
+        gsync_status_param_t                     param              = {0,};
+        xlator_t                                *this               = NULL;
+        glusterd_conf_t                         *priv               = NULL;
+        glusterd_volinfo_t                      *v                  = NULL;
+        glusterd_brickinfo_t                    *b                  = NULL;
+
+        this = THIS;
+        GF_ASSERT (this);
+
+        priv = this->private;
+        GF_ASSERT (priv);
+
+        ret = dict_get_str (dict, "operation", op);
+        if (ret) {
+                gf_msg_debug (this->name, 0,
+                        "dict get on operation type failed");
+                goto out;
+        }
+
+        *gd_op = gd_cli_to_gd_op (*op);
+        if (*gd_op < 0)
+                goto out;
+
+        ret = dict_get_str (dict, "volname", volname);
+
+        if (ret) {
+                gf_msg (this->name, GF_LOG_ERROR, 0,
+                        GD_MSG_DICT_GET_FAILED, "Unable to get volume name");
+                goto out;
+        }
+
+        ret = glusterd_volinfo_find (*volname, volinfo);
+        if (ret) {
+                snprintf (msg, sizeof (msg), "volume: %s does not exist",
+                          *volname);
+                *op_errstr = gf_strdup (msg);
+                goto out;
+        }
+
+        if (GLUSTERD_STATUS_STARTED != (*volinfo)->status) {
+                ret = -1;
+                snprintf (msg, sizeof (msg), "volume: %s is not started",
+                          *volname);
+                *op_errstr = gf_strdup (msg);
+                goto out;
+        }
+
+        ret = glusterd_disallow_op_for_tier (*volinfo, *gd_op, -1);
+        if (ret) {
+                snprintf (msg, sizeof (msg), "%sbrick commands are not "
+                          "supported on tiered volume %s",
+                          (*gd_op == GD_OP_REPLACE_BRICK) ? "replace-" :
+                          "reset-",
+                           *volname);
+                *op_errstr = gf_strdup (msg);
+                goto out;
+        }
+
+        /* If geo-rep is configured, for this volume, it should be stopped. */
+        param.volinfo = *volinfo;
+        ret = glusterd_check_geo_rep_running (&param, op_errstr);
+        if (ret || param.is_active) {
+                ret = -1;
+                goto out;
+        }
+
+        if (glusterd_is_defrag_on(*volinfo)) {
+                snprintf (msg, sizeof(msg), "Volume name %s rebalance is in "
+                          "progress. Please retry after completion", *volname);
+                gf_msg (this->name, GF_LOG_ERROR, 0,
+                        GD_MSG_OIP_RETRY_LATER, "%s", msg);
+                *op_errstr = gf_strdup (msg);
+                ret = -1;
+                goto out;
+        }
+
+        if (dict) {
+                if (!glusterd_is_fuse_available ()) {
+                        gf_msg (this->name, GF_LOG_ERROR, 0,
+                                (*gd_op == GD_OP_REPLACE_BRICK) ?
+                                GD_MSG_RB_CMD_FAIL :
+                                GD_MSG_RESET_BRICK_CMD_FAIL,
+                                "Unable to open /dev/"
+                                "fuse (%s), %s command failed",
+                                strerror (errno), gd_rb_op_to_str (*op));
+                        snprintf (msg, sizeof(msg), "Fuse unavailable\n "
+                                "%s failed", gd_rb_op_to_str (*op));
+                        *op_errstr = gf_strdup (msg);
+                        ret = -1;
+                        goto out;
+                }
+        }
+
+        ret = dict_get_str (dict, "src-brick", src_brick);
+
+        if (ret) {
+                gf_msg (this->name, GF_LOG_ERROR, 0,
+                        GD_MSG_DICT_GET_FAILED, "Unable to get src brick");
+                goto out;
+        }
+
+        gf_msg_debug (this->name, 0, "src brick=%s", *src_brick);
+
+        ret = glusterd_volume_brickinfo_get_by_brick (*src_brick, *volinfo,
+                                                      src_brickinfo,
+                                                      _gf_false);
+        if (ret) {
+                snprintf (msg, sizeof (msg), "brick: %s does not exist in "
+                          "volume: %s", *src_brick, *volname);
+                *op_errstr = gf_strdup (msg);
+                goto out;
+        }
+
+        if (gf_is_local_addr ((*src_brickinfo)->hostname)) {
+                gf_msg_debug (this->name, 0,
+                        "I AM THE SOURCE HOST");
+                if ((*src_brickinfo)->port && rsp_dict) {
+                        ret = dict_set_int32 (rsp_dict, "src-brick-port",
+                                              (*src_brickinfo)->port);
+                        if (ret) {
+                                gf_msg_debug (this->name, 0,
+                                        "Could not set src-brick-port=%d",
+                                        (*src_brickinfo)->port);
+                        }
+                }
+
+                v = *volinfo;
+                b = *src_brickinfo;
+                GLUSTERD_GET_BRICK_PIDFILE (pidfile, v, b,
+                                            priv);
+        }
+
+        ret = 0;
+out:
+        return ret;
+}
+
+int
+glusterd_get_dst_brick_info (char **dst_brick, char *volname, char **op_errstr,
+                             glusterd_brickinfo_t **dst_brickinfo, char **host,
+                             dict_t *dict, char **dup_dstbrick)
+{
+
+        char                                    *path               = NULL;
+        char                                    *c                  = NULL;
+        char                                     msg[2048]          = {0};
+        xlator_t                                *this               = NULL;
+        glusterd_conf_t                         *priv               = NULL;
+        int                                      ret                = 0;
+
+        this = THIS;
+        GF_ASSERT (this);
+
+        priv = this->private;
+        GF_ASSERT (priv);
+
+        ret = dict_get_str (dict, "dst-brick", dst_brick);
+
+        if (ret) {
+                gf_msg (this->name, GF_LOG_ERROR, 0,
+                        GD_MSG_DICT_GET_FAILED,
+                        "Unable to get dest brick.");
+                goto out;
+        }
+
+        gf_msg_debug (this->name, 0, "dst brick=%s", *dst_brick);
+
+        if (!glusterd_store_is_valid_brickpath (volname, *dst_brick) ||
+                !glusterd_is_valid_volfpath (volname, *dst_brick)) {
+                snprintf (msg, sizeof (msg), "brick path %s is too "
+                          "long.", *dst_brick);
+                gf_msg (this->name, GF_LOG_ERROR, 0,
+                        GD_MSG_BRKPATH_TOO_LONG, "%s", msg);
+                *op_errstr = gf_strdup (msg);
+
+                ret = -1;
+                goto out;
+        }
+
+        *dup_dstbrick = gf_strdup (*dst_brick);
+        if (!*dup_dstbrick) {
+                ret = -1;
+                goto out;
+        }
+
+        /*
+         * IPv4 address contains '.' and ipv6 addresses contains ':'
+         * So finding the last occurance of ':' to
+         * mark the start of brick path
+         */
+        c = strrchr(*dup_dstbrick, ':');
+        if (c != NULL) {
+                c[0] = '\0';
+                *host = *dup_dstbrick;
+                path = c++;
+        }
+
+        if (!host || !path) {
+                gf_msg (this->name, GF_LOG_ERROR, 0,
+                        GD_MSG_BAD_FORMAT,
+                        "dst brick %s is not of "
+                        "form <HOSTNAME>:<export-dir>",
+                        *dst_brick);
+                ret = -1;
+                goto out;
+        }
+
+        ret = glusterd_brickinfo_new_from_brick (*dst_brick,
+                                                 dst_brickinfo,
+                                                 _gf_true, NULL);
+        if (ret)
+                goto out;
+
+        ret = 0;
+out:
+        return ret;
+}
+
+glusterd_op_t
+gd_cli_to_gd_op (char *cli_op)
+{
+        if (!strcmp (cli_op, "GF_RESET_OP_START") ||
+            !strcmp(cli_op, "GF_RESET_OP_COMMIT") ||
+            !strcmp (cli_op, "GF_RESET_OP_COMMIT_FORCE")) {
+                return GD_OP_RESET_BRICK;
+        }
+
+        if (!strcmp (cli_op, "GF_REPLACE_OP_COMMIT_FORCE"))
+                return GD_OP_REPLACE_BRICK;
+
+        return -1;
+}
+
+char *
+gd_rb_op_to_str (char *op)
+{
+        if (!strcmp (op, "GF_RESET_OP_START"))
+                return "reset-brick start";
+        if (!strcmp (op, "GF_RESET_OP_COMMIT"))
+                return "reset-brick commit";
+        if (!strcmp (op, "GF_RESET_OP_COMMIT_FORCE"))
+                return "reset-brick commit force";
+        if (!strcmp (op, "GF_REPLACE_OP_COMMIT_FORCE"))
+                return "replace-brick commit force";
+        return NULL;
+}