| Message ID | 68672de3-9fb5-e90b-814f-850185762029@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | nfs-blkmapd: PID file read by systemd failed | expand |
friendly ping, thanks. On 2022/10/11 17:33, zhanchengbin wrote: > When started nfs-blkmap.service, the PID file can't be opened, The > cause is that the child process does not create the PID file before > the systemd reads the PID file. > Adding "ExecStartPost=/bin/sleep 0.1" to > /usr/lib/systemd/system/nfs-blkmap.service will probably solve this > problem, However, there is no guarantee that the above solutions are > effective under high cpu pressure.So replace the daemon function with > the fork function, and put the behavior of creating the PID file in > the parent process to solve the above problems. > > Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com> > Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> > --- > utils/blkmapd/device-discovery.c | 48 +++++++++++++++++++++----------- > 1 file changed, 32 insertions(+), 16 deletions(-) > > diff --git a/utils/blkmapd/device-discovery.c > b/utils/blkmapd/device-discovery.c > index 2736ac89..4d97ac72 100644 > --- a/utils/blkmapd/device-discovery.c > +++ b/utils/blkmapd/device-discovery.c > @@ -507,28 +507,44 @@ int main(int argc, char **argv) > if (fg) { > openlog("blkmapd", LOG_PERROR, 0); > } else { > - if (daemon(0, 0) != 0) { > - fprintf(stderr, "Daemonize failed\n"); > + pid_t pid = fork(); > + if (pid < 0) { > + fprintf(stderr, "fork error\n"); > exit(1); > + } else if (pid != 0) { > + pidfd = open(PID_FILE, O_WRONLY | O_CREAT, 0644); > + if (pidfd < 0) { > + fprintf(stderr, "Create pid file %s failed\n", PID_FILE); > + exit(1); > + } > + > + if (lockf(pidfd, F_TLOCK, 0) < 0) { > + fprintf(stderr, "Already running; Exiting!"); > + close(pidfd); > + exit(1); > + } > + if (ftruncate(pidfd, 0) < 0) > + fprintf(stderr, "ftruncate on %s failed: m\n", PID_FILE); > + sprintf(pidbuf, "%d\n", pid); > + if (write(pidfd, pidbuf, strlen(pidbuf)) != > (ssize_t)strlen(pidbuf)) > + fprintf(stderr, "write on %s failed: m\n", PID_FILE); > + exit(0); > } > > - openlog("blkmapd", LOG_PID, 0); > - pidfd = open(PID_FILE, O_WRONLY | O_CREAT, 0644); > - if (pidfd < 0) { > - BL_LOG_ERR("Create pid file %s failed\n", PID_FILE); > - exit(1); > + (void)setsid(); > + if (chdir("/")) { > + fprintf(stderr, "chdir error\n"); > } > + int fd = open("/dev/null", O_RDWR, 0); > + if (fd >= 0) { > + (void)dup2(fd, STDIN_FILENO); > + (void)dup2(fd, STDOUT_FILENO); > + (void)dup2(fd, STDERR_FILENO); > > - if (lockf(pidfd, F_TLOCK, 0) < 0) { > - BL_LOG_ERR("Already running; Exiting!"); > - close(pidfd); > - exit(1); > + (void)close(fd); > } > - if (ftruncate(pidfd, 0) < 0) > - BL_LOG_WARNING("ftruncate on %s failed: m\n", PID_FILE); > - sprintf(pidbuf, "%d\n", getpid()); > - if (write(pidfd, pidbuf, strlen(pidbuf)) != > (ssize_t)strlen(pidbuf)) > - BL_LOG_WARNING("write on %s failed: m\n", PID_FILE); > + > + openlog("blkmapd", LOG_PID, 0); > } > > signal(SIGINT, sig_die);
Hey! Thanks for the ping!! Bakeathon sucked up a couples weeks! On 10/11/22 5:33 AM, zhanchengbin wrote: > When started nfs-blkmap.service, the PID file can't be opened, The > cause is that the child process does not create the PID file before > the systemd reads the PID file. > Adding "ExecStartPost=/bin/sleep 0.1" to > /usr/lib/systemd/system/nfs-blkmap.service will probably solve this > problem, However, there is no guarantee that the above solutions are > effective under high cpu pressure.So replace the daemon function with > the fork function, and put the behavior of creating the PID file in > the parent process to solve the above problems. I understand what you are trying to do... but unfortunately this patch does not apply to the latest release.... So I'm a bit concern on the amount to testing was done. Please repost a patch that applies cleanly. steved. > > Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com> > Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> > --- > utils/blkmapd/device-discovery.c | 48 +++++++++++++++++++++----------- > 1 file changed, 32 insertions(+), 16 deletions(-) > > diff --git a/utils/blkmapd/device-discovery.c > b/utils/blkmapd/device-discovery.c > index 2736ac89..4d97ac72 100644 > --- a/utils/blkmapd/device-discovery.c > +++ b/utils/blkmapd/device-discovery.c > @@ -507,28 +507,44 @@ int main(int argc, char **argv) > if (fg) { > openlog("blkmapd", LOG_PERROR, 0); > } else { > - if (daemon(0, 0) != 0) { > - fprintf(stderr, "Daemonize failed\n"); > + pid_t pid = fork(); > + if (pid < 0) { > + fprintf(stderr, "fork error\n"); > exit(1); > + } else if (pid != 0) { > + pidfd = open(PID_FILE, O_WRONLY | O_CREAT, 0644); > + if (pidfd < 0) { > + fprintf(stderr, "Create pid file %s failed\n", PID_FILE); > + exit(1); > + } > + > + if (lockf(pidfd, F_TLOCK, 0) < 0) { > + fprintf(stderr, "Already running; Exiting!"); > + close(pidfd); > + exit(1); > + } > + if (ftruncate(pidfd, 0) < 0) > + fprintf(stderr, "ftruncate on %s failed: m\n", PID_FILE); > + sprintf(pidbuf, "%d\n", pid); > + if (write(pidfd, pidbuf, strlen(pidbuf)) != > (ssize_t)strlen(pidbuf)) > + fprintf(stderr, "write on %s failed: m\n", PID_FILE); > + exit(0); > } > > - openlog("blkmapd", LOG_PID, 0); > - pidfd = open(PID_FILE, O_WRONLY | O_CREAT, 0644); > - if (pidfd < 0) { > - BL_LOG_ERR("Create pid file %s failed\n", PID_FILE); > - exit(1); > + (void)setsid(); > + if (chdir("/")) { > + fprintf(stderr, "chdir error\n"); > } > + int fd = open("/dev/null", O_RDWR, 0); > + if (fd >= 0) { > + (void)dup2(fd, STDIN_FILENO); > + (void)dup2(fd, STDOUT_FILENO); > + (void)dup2(fd, STDERR_FILENO); > > - if (lockf(pidfd, F_TLOCK, 0) < 0) { > - BL_LOG_ERR("Already running; Exiting!"); > - close(pidfd); > - exit(1); > + (void)close(fd); > } > - if (ftruncate(pidfd, 0) < 0) > - BL_LOG_WARNING("ftruncate on %s failed: m\n", PID_FILE); > - sprintf(pidbuf, "%d\n", getpid()); > - if (write(pidfd, pidbuf, strlen(pidbuf)) != > (ssize_t)strlen(pidbuf)) > - BL_LOG_WARNING("write on %s failed: m\n", PID_FILE); > + > + openlog("blkmapd", LOG_PID, 0); > } > > signal(SIGINT, sig_die);
diff --git a/utils/blkmapd/device-discovery.c b/utils/blkmapd/device-discovery.c index 2736ac89..4d97ac72 100644 --- a/utils/blkmapd/device-discovery.c +++ b/utils/blkmapd/device-discovery.c @@ -507,28 +507,44 @@ int main(int argc, char **argv) if (fg) { openlog("blkmapd", LOG_PERROR, 0); } else { - if (daemon(0, 0) != 0) { - fprintf(stderr, "Daemonize failed\n"); + pid_t pid = fork(); + if (pid < 0) { + fprintf(stderr, "fork error\n"); exit(1); + } else if (pid != 0) { + pidfd = open(PID_FILE, O_WRONLY | O_CREAT, 0644); + if (pidfd < 0) { + fprintf(stderr, "Create pid file %s failed\n", PID_FILE); + exit(1); + } + + if (lockf(pidfd, F_TLOCK, 0) < 0) { + fprintf(stderr, "Already running; Exiting!"); + close(pidfd); + exit(1); + } + if (ftruncate(pidfd, 0) < 0) + fprintf(stderr, "ftruncate on %s failed: m\n", PID_FILE); + sprintf(pidbuf, "%d\n", pid); + if (write(pidfd, pidbuf, strlen(pidbuf)) != (ssize_t)strlen(pidbuf)) + fprintf(stderr, "write on %s failed: m\n", PID_FILE); + exit(0); } - openlog("blkmapd", LOG_PID, 0); - pidfd = open(PID_FILE, O_WRONLY | O_CREAT, 0644); - if (pidfd < 0) { - BL_LOG_ERR("Create pid file %s failed\n", PID_FILE); - exit(1); + (void)setsid(); + if (chdir("/")) { + fprintf(stderr, "chdir error\n"); } + int fd = open("/dev/null", O_RDWR, 0); + if (fd >= 0) { + (void)dup2(fd, STDIN_FILENO); + (void)dup2(fd, STDOUT_FILENO); + (void)dup2(fd, STDERR_FILENO); - if (lockf(pidfd, F_TLOCK, 0) < 0) { - BL_LOG_ERR("Already running; Exiting!"); - close(pidfd); - exit(1); + (void)close(fd); } - if (ftruncate(pidfd, 0) < 0) - BL_LOG_WARNING("ftruncate on %s failed: m\n", PID_FILE); - sprintf(pidbuf, "%d\n", getpid()); - if (write(pidfd, pidbuf, strlen(pidbuf)) != (ssize_t)strlen(pidbuf)) - BL_LOG_WARNING("write on %s failed: m\n", PID_FILE); + + openlog("blkmapd", LOG_PID, 0); } signal(SIGINT, sig_die);