| Message ID | 3e9dfa44-7448-bf0a-8359-7c8229c45246@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v4] nfs-blkmapd: PID file read by systemd failed | expand |
On 11/8/22 10:48 PM, 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> > Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> Committed... steved. > --- > V3->V4: > The previous version cannot be applied. > > 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 bd890598..a565fdbd 100644 > --- a/utils/blkmapd/device-discovery.c > +++ b/utils/blkmapd/device-discovery.c > @@ -498,28 +498,44 @@ 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) { > + BL_LOG_ERR("fork error\n"); > exit(1); > + } else if (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); > + } > + > + if (lockf(pidfd, F_TLOCK, 0) < 0) { > + BL_LOG_ERR("Already running; Exiting!"); > + close(pidfd); > + exit(1); > + } > + if (ftruncate(pidfd, 0) < 0) > + BL_LOG_ERR("ftruncate on %s failed: m\n", PID_FILE); > + sprintf(pidbuf, "%d\n", pid); > + if (write(pidfd, pidbuf, strlen(pidbuf)) != > (ssize_t)strlen(pidbuf)) > + BL_LOG_ERR("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("/")) { > + BL_LOG_ERR("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);
Thanks. On 2022/11/20 3:49, Steve Dickson wrote: > > > On 11/8/22 10:48 PM, 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> >> Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> > Committed... > > steved. >> --- >> V3->V4: >> The previous version cannot be applied. >> >> 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 bd890598..a565fdbd 100644 >> --- a/utils/blkmapd/device-discovery.c >> +++ b/utils/blkmapd/device-discovery.c >> @@ -498,28 +498,44 @@ 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) { >> + BL_LOG_ERR("fork error\n"); >> exit(1); >> + } else if (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); >> + } >> + >> + if (lockf(pidfd, F_TLOCK, 0) < 0) { >> + BL_LOG_ERR("Already running; Exiting!"); >> + close(pidfd); >> + exit(1); >> + } >> + if (ftruncate(pidfd, 0) < 0) >> + BL_LOG_ERR("ftruncate on %s failed: m\n", PID_FILE); >> + sprintf(pidbuf, "%d\n", pid); >> + if (write(pidfd, pidbuf, strlen(pidbuf)) != >> (ssize_t)strlen(pidbuf)) >> + BL_LOG_ERR("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("/")) { >> + BL_LOG_ERR("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 bd890598..a565fdbd 100644 --- a/utils/blkmapd/device-discovery.c +++ b/utils/blkmapd/device-discovery.c @@ -498,28 +498,44 @@ 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) { + BL_LOG_ERR("fork error\n"); exit(1); + } else if (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); + } + + if (lockf(pidfd, F_TLOCK, 0) < 0) { + BL_LOG_ERR("Already running; Exiting!"); + close(pidfd); + exit(1); + } + if (ftruncate(pidfd, 0) < 0) + BL_LOG_ERR("ftruncate on %s failed: m\n", PID_FILE); + sprintf(pidbuf, "%d\n", pid); + if (write(pidfd, pidbuf, strlen(pidbuf)) != (ssize_t)strlen(pidbuf)) + BL_LOG_ERR("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("/")) { + BL_LOG_ERR("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);