From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6451 invoked by alias); 11 Jan 2010 19:19:17 -0000 Received: (qmail 6436 invoked by uid 9805); 11 Jan 2010 19:19:17 -0000 Date: Mon, 11 Jan 2010 19:19:00 -0000 Message-ID: <20100111191917.6434.qmail@sourceware.org> From: snitzer@sourceware.org To: lvm-devel@redhat.com, lvm2-cvs@sourceware.org Subject: LVM2/tools lvm2cmdline.h lvmcmdline.c polldaemon.c Mailing-List: contact lvm2-cvs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: lvm2-cvs-owner@sourceware.org X-SW-Source: 2010-01/txt/msg00051.txt.bz2 CVSROOT: /cvs/lvm2 Module name: LVM2 Changes by: snitzer@sourceware.org 2010-01-11 19:19:17 Modified files: tools : lvm2cmdline.h lvmcmdline.c polldaemon.c Log message: Only allow one return from poll_daemon(). If a child polldaemon was successfully created it must _exit() once it completes. Update _become_daemon() to differentiate between a failed fork() and a successful fork(). Added lvm_return_code() to lvmcmdline.[ch] Patches: http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/tools/lvm2cmdline.h.diff?cvsroot=lvm2&r1=1.8&r2=1.9 http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/tools/lvmcmdline.c.diff?cvsroot=lvm2&r1=1.110&r2=1.111 http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/tools/polldaemon.c.diff?cvsroot=lvm2&r1=1.30&r2=1.31 --- LVM2/tools/lvm2cmdline.h 2008/12/19 18:51:02 1.8 +++ LVM2/tools/lvm2cmdline.h 2010/01/11 19:19:17 1.9 @@ -35,6 +35,7 @@ void lvm_register_commands(void); int lvm_split(char *str, int *argc, char **argv, int max); int lvm_run_command(struct cmd_context *cmd, int argc, char **argv); +int lvm_return_code(int ret); int lvm_shell(struct cmd_context *cmd, struct cmdline_context *cmdline); #endif --- LVM2/tools/lvmcmdline.c 2010/01/11 15:40:04 1.110 +++ LVM2/tools/lvmcmdline.c 2010/01/11 19:19:17 1.111 @@ -1070,6 +1070,11 @@ return ret; } +int lvm_return_code(int ret) +{ + return (ret == ECMD_PROCESSED ? 0 : ret); +} + int lvm_split(char *str, int *argc, char **argv, int max) { char *b = str, *e; @@ -1389,7 +1394,5 @@ out: lvm_fin(cmd); - if (ret == ECMD_PROCESSED) - ret = 0; - return ret; + return lvm_return_code(ret); } --- LVM2/tools/polldaemon.c 2010/01/08 21:53:08 1.30 +++ LVM2/tools/polldaemon.c 2010/01/11 19:19:17 1.31 @@ -15,6 +15,7 @@ #include "tools.h" #include "polldaemon.h" +#include "lvm2cmdline.h" #include #include @@ -23,6 +24,12 @@ while (wait4(-1, NULL, WNOHANG | WUNTRACED, NULL) > 0) ; } +/* + * returns: + * -1 if the fork failed + * 0 if the parent + * 1 if the child + */ static int _become_daemon(struct cmd_context *cmd) { pid_t pid; @@ -37,7 +44,7 @@ if ((pid = fork()) == -1) { log_error("fork failed: %s", strerror(errno)); - return 1; + return -1; } /* Parent */ @@ -232,12 +239,20 @@ } } +/* + * Only allow *one* return from poll_daemon() (the parent). + * If there is a child it must exit (ignoring the memory leak messages). + * - 'background' is advisory so a child polldaemon may not be used even + * if it was requested. + */ int poll_daemon(struct cmd_context *cmd, const char *name, const char *uuid, unsigned background, uint32_t lv_type, struct poll_functions *poll_fns, const char *progress_title) { struct daemon_parms parms; + int daemon_mode = 0; + int ret = ECMD_PROCESSED; parms.aborting = arg_is_set(cmd, abort_ARG); parms.background = background; @@ -260,9 +275,11 @@ } if (parms.background) { - if (!_become_daemon(cmd)) - return ECMD_PROCESSED; /* Parent */ - parms.progress_display = 0; + daemon_mode = _become_daemon(cmd); + if (daemon_mode == 0) + return ECMD_PROCESSED; /* Parent */ + else if (daemon_mode == 1) + parms.progress_display = 0; /* Child */ /* FIXME Use wait_event (i.e. interval = 0) and */ /* fork one daemon per copy? */ } @@ -273,10 +290,21 @@ if (name) { if (!_wait_for_single_lv(cmd, name, uuid, &parms)) { stack; - return ECMD_FAILED; + ret = ECMD_FAILED; } } else _poll_for_all_vgs(cmd, &parms); - return ECMD_PROCESSED; + if (parms.background && daemon_mode == 1) { + /* + * child was successfully forked: + * background polldaemon must not return to the caller + * because it will redundantly continue performing the + * caller's task (that the parent already performed) + */ + /* FIXME Attempt proper cleanup */ + _exit(lvm_return_code(ret)); + } + + return ret; }