glusterd: handling brick termination in brick-mux

Problem: There's a race between the last glusterfs_handle_terminate()
response sent to glusterd and the kill that happens immediately if the
terminated brick is the last brick.

Solution: When it is a last brick for the brick process, instead of glusterfsd
killing itself, glusterd will kill the process in case of brick multiplexing.
And also changing gf_attach utility accordingly.

Change-Id: I386c19ca592536daa71294a13d9fc89a26d7e8c0
fixes: bz#1545048
BUG: 1545048
Signed-off-by: Sanju Rakonde <srakonde@redhat.com>

4 files changed, 55 insertions, 25 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-pmap.c b/xlators/mgmt/glusterd/src/glusterd-pmap.c
index 98b1aaa63af..8ef285bf48d 100644
--- a/xlators/mgmt/glusterd/src/glusterd-pmap.c
+++ b/xlators/mgmt/glusterd/src/glusterd-pmap.c
@@ -557,6 +557,7 @@ __gluster_pmap_signout (rpcsvc_request_t *req)
         glusterd_brickinfo_t *brickinfo            = NULL;
         char                  pidfile[PATH_MAX]    = {0};
         char                  brick_path[PATH_MAX] = {0,};
+        int                   kill_pid             = -1;
 
         this = THIS;
         GF_VALIDATE_OR_GOTO ("glusterd", this, fail);
@@ -606,7 +607,8 @@ __gluster_pmap_signout (rpcsvc_request_t *req)
                          * removed in the brick op phase. This situation would
                          * arise when the brick is killed explicitly from the
                          * backend */
-                        ret = glusterd_brick_process_remove_brick (brickinfo);
+                        ret = glusterd_brick_process_remove_brick (brickinfo,
+                                                                   &kill_pid);
                         if (ret) {
                                 gf_msg_debug (this->name, 0, "Couldn't remove "
                                               "brick %s:%s from brick process",
diff --git a/xlators/mgmt/glusterd/src/glusterd-syncop.c b/xlators/mgmt/glusterd/src/glusterd-syncop.c
index 31b08d76adc..e5d4421deb4 100644
--- a/xlators/mgmt/glusterd/src/glusterd-syncop.c
+++ b/xlators/mgmt/glusterd/src/glusterd-syncop.c
@@ -958,7 +958,6 @@ gd_syncop_mgmt_brick_op (struct rpc_clnt *rpc, glusterd_pending_node_t *pnode,
         gd1_mgmt_brick_op_req  *req  = NULL;
         int                    ret  = 0;
         xlator_t               *this = NULL;
-        glusterd_brickinfo_t   *brickinfo = NULL;
 
         this = THIS;
         args.op_ret = -1;
@@ -987,22 +986,6 @@ gd_syncop_mgmt_brick_op (struct rpc_clnt *rpc, glusterd_pending_node_t *pnode,
                 else
                         GF_FREE (args.errstr);
         }
-        if (op == GD_OP_STOP_VOLUME || op == GD_OP_REMOVE_BRICK) {
-                if (args.op_ret == 0) {
-                        brickinfo = pnode->node;
-                        ret = glusterd_brick_process_remove_brick (brickinfo);
-                        if (ret) {
-                                gf_msg ("glusterd", GF_LOG_ERROR, 0,
-                                        GD_MSG_BRICKPROC_REM_BRICK_FAILED,
-                                        "Removing brick %s:%s from brick"
-                                        " process failed",
-                                        brickinfo->hostname,
-                                        brickinfo->path);
-                                args.op_ret = ret;
-                                goto out;
-                        }
-                }
-        }
 
         if (GD_OP_STATUS_VOLUME == op) {
                 ret = dict_set_int32 (args.dict, "index", pnode->index);
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index af30756c947..8e71756b927 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -69,6 +69,7 @@
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
+#include <sys/wait.h>
 #include <rpc/pmap_clnt.h>
 #include <unistd.h>
 #include <fnmatch.h>
@@ -2313,7 +2314,8 @@ glusterd_brickprocess_delete (glusterd_brick_proc_t *brick_proc)
 }
 
 int
-glusterd_brick_process_remove_brick (glusterd_brickinfo_t *brickinfo)
+glusterd_brick_process_remove_brick (glusterd_brickinfo_t *brickinfo,
+                                     int *kill_pid)
 {
         int                      ret = -1;
         xlator_t                *this = NULL;
@@ -2352,6 +2354,7 @@ glusterd_brick_process_remove_brick (glusterd_brickinfo_t *brickinfo)
 
                 /* If all bricks have been removed, delete the brick process */
                 if (brick_proc->brick_count == 0) {
+                        *kill_pid = 1;
                         ret = glusterd_brickprocess_delete (brick_proc);
                         if (ret)
                                 goto out;
@@ -2454,7 +2457,11 @@ glusterd_volume_stop_glusterfs (glusterd_volinfo_t *volinfo,
         glusterd_conf_t *conf                   = NULL;
         int             ret                     = -1;
         char            *op_errstr              = NULL;
-        char            pidfile[PATH_MAX]       = {0,};
+        char            pidfile_path[PATH_MAX]  = {0,};
+        int             kill_pid                = -1;
+        FILE            *pidfile                = NULL;
+        pid_t           pid                     = -1;
+        int             status                  = -1;
 
         GF_ASSERT (volinfo);
         GF_ASSERT (brickinfo);
@@ -2467,7 +2474,7 @@ glusterd_volume_stop_glusterfs (glusterd_volinfo_t *volinfo,
 
         ret = 0;
 
-        ret = glusterd_brick_process_remove_brick (brickinfo);
+        ret = glusterd_brick_process_remove_brick (brickinfo, &kill_pid);
         if (ret) {
                 gf_msg_debug (this->name, 0, "Couldn't remove brick from"
                               " brick process");
@@ -2510,10 +2517,47 @@ glusterd_volume_stop_glusterfs (glusterd_volinfo_t *volinfo,
                 ret = 0;
         }
 
-        GLUSTERD_GET_BRICK_PIDFILE (pidfile, volinfo, brickinfo, conf);
+        GLUSTERD_GET_BRICK_PIDFILE (pidfile_path, volinfo, brickinfo, conf);
+        if (kill_pid == 1 && is_brick_mx_enabled ()) {
+                pidfile = fopen (pidfile_path, "r");
+                if (!pidfile) {
+                        gf_msg (this->name, GF_LOG_ERROR, errno,
+                                GD_MSG_FILE_OP_FAILED,
+                                "Unable to open pidfile: %s", pidfile_path);
+                        ret = -1;
+                        goto out;
+                }
+
+                ret = fscanf (pidfile, "%d", &pid);
+                if (ret <= 0) {
+                        gf_msg (this->name, GF_LOG_ERROR, errno,
+                                GD_MSG_FILE_OP_FAILED,
+                                "Unable to get pid of brick process");
+                        ret = -1;
+                        goto out;
+                }
+
+                if (conf->op_version >= GD_OP_VERSION_4_1_0) {
+                        while (conf->blockers) {
+                                synclock_unlock (&conf->big_lock);
+                                sleep (1);
+                                synclock_lock (&conf->big_lock);
+                        }
+                }
+                gf_log (this->name, GF_LOG_INFO,
+                        "terminating the brick process "
+                        "%d after loss of last brick %s of the volume %s",
+                        pid, brickinfo->path, volinfo->volname);
+                kill (pid, SIGTERM);
+                waitpid (pid, &status, 0);
+                pmap_registry_remove (this, brickinfo->port, brickinfo->path,
+                                      GF_PMAP_PORT_BRICKSERVER, NULL,
+                                      _gf_true);
+                ret = 0;
+        }
 
-        gf_msg_debug (this->name,  0, "Unlinking pidfile %s", pidfile);
-        (void) sys_unlink (pidfile);
+        gf_msg_debug (this->name,  0, "Unlinking pidfile %s", pidfile_path);
+        (void) sys_unlink (pidfile_path);
 
         brickinfo->status = GF_BRICK_STOPPED;
         brickinfo->start_triggered = _gf_false;
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.h b/xlators/mgmt/glusterd/src/glusterd-utils.h
index 0e9e54a0687..8118c994974 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.h
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.h
@@ -182,7 +182,8 @@ glusterd_brick_process_add_brick (glusterd_brickinfo_t *brickinfo,
                                   glusterd_volinfo_t *volinfo);
 
 int
-glusterd_brick_process_remove_brick (glusterd_brickinfo_t *brickinfo);
+glusterd_brick_process_remove_brick (glusterd_brickinfo_t *brickinfo,
+                                     int *kill_pid);
 
 int
 glusterd_brick_proc_for_port (int port, glusterd_brick_proc_t **brickprocess);