From: Andre Noll Date: Fri, 20 Jul 2012 14:05:41 +0000 (+0200) Subject: Merge branch 't/exec_cleanups' X-Git-Tag: v0.1.5~15 X-Git-Url: http://git.tuebingen.mpg.de/?p=dss.git;a=commitdiff_plain;h=51ac947011498645efe9e52687457b2ab73aeac2;hp=a0b6810b7e5ac1d11b4b8e555c8304b65bce8559 Merge branch 't/exec_cleanups' 06a23c Simplify exec functions. Was cooking quite long and no problems showed up. --- diff --git a/dss.c b/dss.c index 3508d38..968ba59 100644 --- a/dss.c +++ b/dss.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2008-2010 Andre Noll + * Copyright (C) 2008-2011 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -287,29 +287,22 @@ static int next_snapshot_is_due(void) return 0; } -static int pre_create_hook(void) +static void pre_create_hook(void) { - int ret, fds[3] = {0, 0, 0}; - assert(snapshot_creation_status == HS_READY); /* make sure that the next snapshot time will be recomputed */ invalidate_next_snapshot_time(); DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg); - ret = dss_exec_cmdline_pid(&create_pid, - conf.pre_create_hook_arg, fds); - if (ret < 0) - return ret; + dss_exec_cmdline_pid(&create_pid, conf.pre_create_hook_arg); snapshot_creation_status = HS_PRE_RUNNING; - return ret; } -static int pre_remove_hook(struct snapshot *s, const char *why) +static void pre_remove_hook(struct snapshot *s, const char *why) { - int ret, fds[3] = {0, 0, 0}; char *cmd; if (!s) - return 0; + return; DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name); assert(snapshot_removal_status == HS_READY); assert(remove_pid == 0); @@ -322,18 +315,14 @@ static int pre_remove_hook(struct snapshot *s, const char *why) cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg, conf.dest_dir_arg, s->name); DSS_DEBUG_LOG("executing %s\n", cmd); - ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds); + dss_exec_cmdline_pid(&remove_pid, cmd); free(cmd); - if (ret < 0) - return ret; snapshot_removal_status = HS_PRE_RUNNING; - return ret; } static int exec_rm(void) { struct snapshot *s = snapshot_currently_being_removed; - int fds[3] = {0, 0, 0}; char *new_name = being_deleted_name(s); char *argv[] = {"rm", "-rf", new_name, NULL}; int ret; @@ -345,9 +334,7 @@ static int exec_rm(void) ret = dss_rename(s->name, new_name); if (ret < 0) goto out; - ret = dss_exec(&remove_pid, argv[0], argv, fds); - if (ret < 0) - goto out; + dss_exec(&remove_pid, argv[0], argv); snapshot_removal_status = HS_RUNNING; out: free(new_name); @@ -563,31 +550,24 @@ static int try_to_free_disk_space(void) ret = -ERRNO_TO_DSS_ERROR(ENOSPC); goto out; remove: - ret = pre_remove_hook(victim, why); + pre_remove_hook(victim, why); out: free_snapshot_list(&sl); return ret; } -static int post_create_hook(void) +static void post_create_hook(void) { - int ret, fds[3] = {0, 0, 0}; - char *cmd; - - cmd = make_message("%s %s/%s", conf.post_create_hook_arg, + char *cmd = make_message("%s %s/%s", conf.post_create_hook_arg, conf.dest_dir_arg, path_to_last_complete_snapshot); DSS_NOTICE_LOG("executing %s\n", cmd); - ret = dss_exec_cmdline_pid(&create_pid, cmd, fds); + dss_exec_cmdline_pid(&create_pid, cmd); free(cmd); - if (ret < 0) - return ret; snapshot_creation_status = HS_POST_RUNNING; - return ret; } -static int post_remove_hook(void) +static void post_remove_hook(void) { - int ret, fds[3] = {0, 0, 0}; char *cmd; struct snapshot *s = snapshot_currently_being_removed; @@ -596,12 +576,9 @@ static int post_remove_hook(void) cmd = make_message("%s %s/%s", conf.post_remove_hook_arg, conf.dest_dir_arg, s->name); DSS_NOTICE_LOG("executing %s\n", cmd); - ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds); + dss_exec_cmdline_pid(&remove_pid, cmd); free(cmd); - if (ret < 0) - return ret; snapshot_removal_status = HS_POST_RUNNING; - return ret; } static void dss_kill(pid_t pid, int sig, const char *msg) @@ -1143,14 +1120,12 @@ static void free_rsync_argv(char **argv) static int create_snapshot(char **argv) { - int ret, fds[3] = {0, 0, 0}; + int ret; ret = rename_resume_snap(current_snapshot_creation_time); if (ret < 0) return ret; - ret = dss_exec(&create_pid, argv[0], argv, fds); - if (ret < 0) - return ret; + dss_exec(&create_pid, argv[0], argv); snapshot_creation_status = HS_RUNNING; return ret; } @@ -1192,9 +1167,7 @@ static int select_loop(void) continue; } if (snapshot_removal_status == HS_SUCCESS) { - ret = post_remove_hook(); - if (ret < 0) - goto out; + post_remove_hook(); continue; } ret = try_to_free_disk_space(); @@ -1209,9 +1182,7 @@ static int select_loop(void) case HS_READY: if (!next_snapshot_is_due()) continue; - ret = pre_create_hook(); - if (ret < 0) - goto out; + pre_create_hook(); continue; case HS_PRE_RUNNING: case HS_RUNNING: @@ -1234,9 +1205,7 @@ static int select_loop(void) goto out; continue; case HS_SUCCESS: - ret = post_create_hook(); - if (ret < 0) - goto out; + post_create_hook(); continue; } } @@ -1246,12 +1215,11 @@ out: static void exit_hook(int exit_code) { - int fds[3] = {0, 0, 0}; char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL}; pid_t pid; DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]); - dss_exec(&pid, conf.exit_hook_arg, argv, fds); + dss_exec(&pid, conf.exit_hook_arg, argv); } static int com_run(void) @@ -1302,9 +1270,7 @@ rm: ret = 0; goto out; } - ret = pre_remove_hook(victim, why); - if (ret < 0) - goto out; + pre_remove_hook(victim, why); if (snapshot_removal_status == HS_PRE_RUNNING) { ret = wait_for_remove_process(); if (ret < 0) @@ -1320,9 +1286,7 @@ rm: goto out; if (snapshot_removal_status != HS_SUCCESS) goto out; - ret = post_remove_hook(); - if (ret < 0) - goto out; + post_remove_hook(); if (snapshot_removal_status != HS_POST_RUNNING) goto out; ret = wait_for_remove_process(); @@ -1354,9 +1318,7 @@ static int com_create(void) free(msg); return 1; } - ret = pre_create_hook(); - if (ret < 0) - return ret; + pre_create_hook(); if (create_pid) { ret = wait_for_process(create_pid, &status); if (ret < 0) diff --git a/exec.c b/exec.c index 2887cb2..adfd24d 100644 --- a/exec.c +++ b/exec.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2003-2010 Andre Noll + * Copyright (C) 2003-2011 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -7,155 +7,60 @@ /** \file exec.c Helper functions for spawning new processes. */ #include -#include -#include -#include #include #include #include #include - +#include #include "gcc-compat.h" #include "log.h" #include "error.h" #include "string.h" - /** - * Spawn a new process and redirect fd 0, 1, and 2. + * Spawn a new process using execvp(). * * \param pid Will hold the pid of the created process upon return. * \param file Path of the executable to execute. * \param args The argument array for the command. - * \param fds a Pointer to a value-result array. * * \return Standard. * - * \sa null(4), pipe(2), dup2(2), fork(2), exec(3). + * \sa fork(2), exec(3). */ -int dss_exec(pid_t *pid, const char *file, char *const *const args, int *fds) +void dss_exec(pid_t *pid, const char *file, char *const *const args) { - int ret, in[2] = {-1, -1}, out[2] = {-1, -1}, err[2] = {-1, -1}, - null = -1; /* ;) */ - - ret = -E_DUP_PIPE; - if (fds[0] > 0 && pipe(in) < 0) - goto err_out; - if (fds[1] > 0 && pipe(out) < 0) - goto err_out; - if (fds[2] > 0 && pipe(err) < 0) - goto err_out; - if (!fds[0] || !fds[1] || !fds[2]) { - ret = -E_NULL_OPEN; - null = open("/dev/null", O_RDWR); - if (null < 0) - goto err_out; - } - if ((*pid = fork()) < 0) + if ((*pid = fork()) < 0) { + DSS_EMERG_LOG("fork error: %s\n", strerror(errno)); exit(EXIT_FAILURE); - if (!(*pid)) { /* child */ - if (fds[0] >= 0) { - if (fds[0]) { - close(in[1]); - if (in[0] != STDIN_FILENO) - dup2(in[0], STDIN_FILENO); - } else - dup2(null, STDIN_FILENO); - } - if (fds[1] >= 0) { - if (fds[1]) { - close(out[0]); - if (out[1] != STDOUT_FILENO) - dup2(out[1], STDOUT_FILENO); - } else - dup2(null, STDOUT_FILENO); - } - if (fds[2] >= 0) { - if (fds[2]) { - close(err[0]); - if (err[1] != STDERR_FILENO) - dup2(err[1], STDERR_FILENO); - } else - dup2(null, STDERR_FILENO); - } - if (null >= 0) - close(null); - signal(SIGINT, SIG_DFL); - signal(SIGTERM, SIG_DFL); - signal(SIGCHLD, SIG_DFL); - execvp(file, args); - _exit(EXIT_FAILURE); - } - if (fds[0] > 0) { - close(in[0]); - *fds = in[1]; - } - if (fds[1] > 0) { - close(out[1]); - *(fds + 1) = out[0]; - } - if (fds[2] > 0) { - close(err[1]); - *(fds + 2) = err[0]; } - if (null >= 0) - close(null); - return 1; -err_out: - DSS_ERROR_LOG("failed to exec %s\n", file); - if (err[0] >= 0) - close(err[0]); - if (err[1] >= 0) - close(err[1]); - if (out[0] >= 0) - close(out[0]); - if (out[1] >= 0) - close(out[1]); - if (in[0] >= 0) - close(in[0]); - if (in[1] >= 0) - close(in[1]); - if (null >= 0) - close(null); - return ret; + if (*pid) /* parent */ + return; + signal(SIGINT, SIG_DFL); + signal(SIGTERM, SIG_DFL); + signal(SIGCHLD, SIG_DFL); + execvp(file, args); + DSS_EMERG_LOG("execvp error: %s\n", strerror(errno)); + _exit(EXIT_FAILURE); } - /** - * Exec the given command. + * Exec the command given as a command line. * * \param pid Will hold the pid of the created process upon return. * \param cmdline Holds the command and its arguments, seperated by spaces. - * \param fds A pointer to a value-result array. - * - * This function uses fork/exec to create a new process. \a fds must be a - * pointer to three integers, corresponding to stdin, stdout and stderr - * respectively. It specifies how to deal with fd 0, 1, 2 in the child. The - * contents of \a fds are interpreted as follows: - * - * - fd[i] < 0: leave fd \a i alone. - * - fd[i] = 0: dup fd \a i to \p /dev/null. - * - fd[i] > 0: create a pipe and dup i to one end of that pipe. - * Upon return, fd[i] contains the file descriptor of the pipe. * - * In any case, all unneeded filedescriptors are closed. + * This function uses fork/exec to create a new process. * * \return Standard. */ -int dss_exec_cmdline_pid(pid_t *pid, const char *cmdline, int *fds) +void dss_exec_cmdline_pid(pid_t *pid, const char *cmdline) { - int argc, ret; - char **argv; - char *tmp = dss_strdup(cmdline); + char **argv, *tmp = dss_strdup(cmdline); - if (!tmp) - exit(EXIT_FAILURE); - argc = split_args(tmp, &argv, " \t"); - ret = dss_exec(pid, argv[0], argv, fds); + split_args(tmp, &argv, " \t"); + dss_exec(pid, argv[0], argv); free(argv); free(tmp); - return ret; } - - diff --git a/exec.h b/exec.h index b95aba1..31efc27 100644 --- a/exec.h +++ b/exec.h @@ -1,3 +1,2 @@ -int dss_exec(pid_t *pid, const char *file, char *const *const args, int *fds); -int dss_exec_cmdline_pid(pid_t *pid, const char *cmdline, int *fds); - +void dss_exec(pid_t *pid, const char *file, char *const *const args); +void dss_exec_cmdline_pid(pid_t *pid, const char *cmdline); diff --git a/string.c b/string.c index d370a81..22d3905 100644 --- a/string.c +++ b/string.c @@ -239,7 +239,7 @@ __must_check __malloc char *dss_logname(void) * * \return The number of substrings found in \a args. */ -__must_check unsigned split_args(char *args, char *** const argv_ptr, const char *delim) +unsigned split_args(char *args, char *** const argv_ptr, const char *delim) { char *p = args; char **argv; diff --git a/string.h b/string.h index a4cbdbe..0f158fe 100644 --- a/string.h +++ b/string.h @@ -6,7 +6,7 @@ __must_check __malloc char *dss_strdup(const char *s); __must_check __malloc char *get_homedir(void); int dss_atoi64(const char *str, int64_t *value); __must_check __malloc char *dss_logname(void); -__must_check unsigned split_args(char *args, char *** const argv_ptr, const char *delim); +unsigned split_args(char *args, char *** const argv_ptr, const char *delim); /** \cond LLONG_MAX and LLONG_LIN might not be defined. */