From: Steve Dickson <steved@redhat.com>
To: zhanchengbin <zhanchengbin1@huawei.com>
Cc: linux-nfs@vger.kernel.org, linfeilong <linfeilong@huawei.com>,
liuzhiqiang26@huawei.com
Subject: Re: [PATCH v3] nfs-blkmapd: PID file read by systemd failed
Date: Tue, 8 Nov 2022 14:59:16 -0500 [thread overview]
Message-ID: <8b3c6919-b4a5-9136-933c-45c352908212@redhat.com> (raw)
In-Reply-To: <c0bd54a6-ff27-ccf7-39b4-a823996bd5af@huawei.com>
Hey!
Again thank you make those changes but once again
nothing applies cleanly... I think your email client
is reformatting the patch. Please try this:
$ git clone git://linux-nfs.org/~steved/nfs-utils
$ cd nfs-utils
$ edit utils/blkmapd/device-discovery.c
$ git commit -s -a
$ git format-patch -o /tmp/ -1
$ git send-email $DRYRUN --suppress-cc=all --suppress-from \
--no-chain-reply-to \
--from "zhanchengbin <zhanchengbin1@huawei.com>" \
--to "Linux NFS Mailing list <linux-nfs@vger.kernel.org>"
If DRYRUN=--dry-run will test the mailing but not send it.
steved.
On 11/7/22 10:41 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>
> Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
> ---
> V2->V3:
> Replace "fprintf(stderr" with BL_LOG_ERR.
>
> 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);
next prev parent reply other threads:[~2022-11-08 20:00 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-08 3:41 [PATCH v3] nfs-blkmapd: PID file read by systemd failed zhanchengbin
2022-11-08 19:59 ` Steve Dickson [this message]
2022-11-14 1:59 ` zhanchengbin
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