From 670299cf4fc90c1c61032057b6ff570fee7a448e Mon Sep 17 00:00:00 2001 From: Mohammed Rafi KC Date: Mon, 24 Jun 2019 12:00:20 +0530 Subject: glusterd/svc: update pid of mux volumes from the shd process For a normal volume, we are updating the pid from a the process while we do a daemonization or at the end of the init if it is no-daemon mode. Along with updating the pid we also lock the file, to make sure that the process is running fine. With brick mux, we were updating the pidfile from gluterd after an attach/detach request. There are two problems with this approach. 1) We are not holding a pidlock for any file other than parent process. 2) There is a chance for possible race conditions with attach/detach. For example, shd start and a volume stop could race. Let's say we are starting an shd and it is attached to a volume. While we trying to link the pid file to the running process, this would have deleted by the thread that doing a volume stop. Change-Id: I29a00352102877ce09ea3f376ca52affceb5cf1a Updates: bz#1722541 Signed-off-by: Mohammed Rafi KC --- libglusterfs/src/graph.c | 154 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 148 insertions(+), 6 deletions(-) (limited to 'libglusterfs/src/graph.c') diff --git a/libglusterfs/src/graph.c b/libglusterfs/src/graph.c index 42ffb7a8c9b..772820220fd 100644 --- a/libglusterfs/src/graph.c +++ b/libglusterfs/src/graph.c @@ -1473,6 +1473,21 @@ out: return parent_graph; } +int +glusterfs_svc_mux_pidfile_cleanup(gf_volfile_t *volfile_obj) +{ + if (!volfile_obj || !volfile_obj->pidfp) + return 0; + + gf_msg_trace("glusterfsd", 0, "pidfile %s cleanup", volfile_obj->vol_id); + + lockf(fileno(volfile_obj->pidfp), F_ULOCK, 0); + fclose(volfile_obj->pidfp); + volfile_obj->pidfp = NULL; + + return 0; +} + int glusterfs_process_svc_detach(glusterfs_ctx_t *ctx, gf_volfile_t *volfile_obj) { @@ -1509,6 +1524,7 @@ glusterfs_process_svc_detach(glusterfs_ctx_t *ctx, gf_volfile_t *volfile_obj) list_del_init(&volfile_obj->volfile_list); glusterfs_mux_xlator_unlink(parent_graph->top, xl); + glusterfs_svc_mux_pidfile_cleanup(volfile_obj); parent_graph->last_xl = glusterfs_get_last_xlator(parent_graph); parent_graph->xl_count -= graph->xl_count; parent_graph->leaf_count -= graph->leaf_count; @@ -1537,9 +1553,127 @@ out: return ret; } +int +glusterfs_svc_mux_pidfile_setup(gf_volfile_t *volfile_obj, const char *pid_file) +{ + int ret = -1; + FILE *pidfp = NULL; + + if (!pid_file || !volfile_obj) + goto out; + + if (volfile_obj->pidfp) { + ret = 0; + goto out; + } + pidfp = fopen(pid_file, "a+"); + if (!pidfp) { + goto out; + } + volfile_obj->pidfp = pidfp; + + ret = lockf(fileno(pidfp), F_TLOCK, 0); + if (ret) { + ret = 0; + goto out; + } +out: + return ret; +} + +int +glusterfs_svc_mux_pidfile_update(gf_volfile_t *volfile_obj, + const char *pid_file, pid_t pid) +{ + int ret = 0; + FILE *pidfp = NULL; + int old_pid; + + if (!volfile_obj->pidfp) { + ret = glusterfs_svc_mux_pidfile_setup(volfile_obj, pid_file); + if (ret == -1) + goto out; + } + pidfp = volfile_obj->pidfp; + ret = fscanf(pidfp, "%d", &old_pid); + if (ret <= 0) { + goto update; + } + if (old_pid == pid) { + ret = 0; + goto out; + } else { + gf_msg("mgmt", GF_LOG_INFO, 0, LG_MSG_GRAPH_ATTACH_PID_FILE_UPDATED, + "Old pid=%d found in pidfile %s. Cleaning the old pid and " + "Updating new pid=%d", + old_pid, pid_file, pid); + } +update: + ret = sys_ftruncate(fileno(pidfp), 0); + if (ret) { + gf_msg("glusterfsd", GF_LOG_ERROR, errno, + LG_MSG_GRAPH_ATTACH_PID_FILE_UPDATED, + "pidfile %s truncation failed", pid_file); + goto out; + } + + ret = fprintf(pidfp, "%d\n", pid); + if (ret <= 0) { + gf_msg("glusterfsd", GF_LOG_ERROR, errno, + LG_MSG_GRAPH_ATTACH_PID_FILE_UPDATED, "pidfile %s write failed", + pid_file); + goto out; + } + + ret = fflush(pidfp); + if (ret) { + gf_msg("glusterfsd", GF_LOG_ERROR, errno, + LG_MSG_GRAPH_ATTACH_PID_FILE_UPDATED, "pidfile %s write failed", + pid_file); + goto out; + } +out: + return ret; +} + +int +glusterfs_update_mux_pid(dict_t *dict, gf_volfile_t *volfile_obj) +{ + char *file = NULL; + int ret = -1; + + GF_VALIDATE_OR_GOTO("graph", dict, out); + GF_VALIDATE_OR_GOTO("graph", volfile_obj, out); + + ret = dict_get_str(dict, "pidfile", &file); + if (ret < 0) { + gf_msg("mgmt", GF_LOG_ERROR, EINVAL, LG_MSG_GRAPH_SETUP_FAILED, + "Failed to get pidfile from dict for volfile_id=%s", + volfile_obj->vol_id); + } + + ret = glusterfs_svc_mux_pidfile_update(volfile_obj, file, getpid()); + if (ret < 0) { + ret = -1; + gf_msg("mgmt", GF_LOG_ERROR, EINVAL, LG_MSG_GRAPH_SETUP_FAILED, + "Failed to update " + "the pidfile for volfile_id=%s", + volfile_obj->vol_id); + + goto out; + } + + if (ret == 1) + gf_msg("mgmt", GF_LOG_INFO, 0, LG_MSG_GRAPH_ATTACH_PID_FILE_UPDATED, + "PID %d updated in pidfile=%s", getpid(), file); + ret = 0; +out: + return ret; +} int glusterfs_process_svc_attach_volfp(glusterfs_ctx_t *ctx, FILE *fp, - char *volfile_id, char *checksum) + char *volfile_id, char *checksum, + dict_t *dict) { glusterfs_graph_t *graph = NULL; glusterfs_graph_t *parent_graph = NULL; @@ -1622,18 +1756,25 @@ glusterfs_process_svc_attach_volfp(glusterfs_ctx_t *ctx, FILE *fp, ret = -1; goto out; } + volfile_obj->pidfp = NULL; + snprintf(volfile_obj->vol_id, sizeof(volfile_obj->vol_id), "%s", + volfile_id); + + if (strcmp(ctx->cmd_args.process_name, "glustershd") == 0) { + ret = glusterfs_update_mux_pid(dict, volfile_obj); + if (ret == -1) { + goto out; + } + } graph->used = 1; parent_graph->id++; list_add(&graph->list, &ctx->graphs); INIT_LIST_HEAD(&volfile_obj->volfile_list); volfile_obj->graph = graph; - snprintf(volfile_obj->vol_id, sizeof(volfile_obj->vol_id), "%s", - volfile_id); memcpy(volfile_obj->volfile_checksum, checksum, sizeof(volfile_obj->volfile_checksum)); list_add_tail(&volfile_obj->volfile_list, &ctx->volfile_list); - gf_log_dump_graph(fp, graph); graph = NULL; @@ -1661,7 +1802,8 @@ out: int glusterfs_mux_volfile_reconfigure(FILE *newvolfile_fp, glusterfs_ctx_t *ctx, - gf_volfile_t *volfile_obj, char *checksum) + gf_volfile_t *volfile_obj, char *checksum, + dict_t *dict) { glusterfs_graph_t *oldvolfile_graph = NULL; glusterfs_graph_t *newvolfile_graph = NULL; @@ -1710,7 +1852,7 @@ glusterfs_mux_volfile_reconfigure(FILE *newvolfile_fp, glusterfs_ctx_t *ctx, } volfile_obj = NULL; ret = glusterfs_process_svc_attach_volfp(ctx, newvolfile_fp, vol_id, - checksum); + checksum, dict); goto out; } -- cgit