[Libguestfs] [PATCH 1/2] daemon: run 'udevadm settle' with --exit-if-exists option

Add udev_settle_file() to run 'udevadm settle' with --exit-if-exists option. It will slightly reduce the waiting-time for pending events if we need to wait for events related to a particular device/file. Signed-off-by: Pavel Butsykin <pbutsykin(a)virtuozzo.com&gt; --- daemon/daemon.h | 2 ++ daemon/guestfsd.c | 20 ++++++++++++++++---- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/daemon/daemon.h b/daemon/daemon.h index 79a5288f6..90ebaafbe 100644 --- a/daemon/daemon.h +++ b/daemon/daemon.h @@ -141,6 +141,8 @@ extern int parse_btrfsvol (const char *desc, mountable_t *mountable); extern int prog_exists (const char *prog); +extern void udev_settle_file (const char *file); + extern void udev_settle (void); extern int random_name (char *template); diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c index 85ce5d2ad..dccfa15bc 100644 --- a/daemon/guestfsd.c +++ b/daemon/guestfsd.c @@ -1213,13 +1213,18 @@ random_name (char *template) * fussed if it fails. */ void -udev_settle (void) +udev_settle_file (const char *file) { - char cmd[80]; + size_t cmd_size = strlen (str_udevadm) + + sizeof (" settle") + + sizeof (" --debug") + + (file ? sizeof (" --exit-if-exists=") + strlen (file) : 0); + char *cmd = malloc (cmd_size); int r; - snprintf (cmd, sizeof cmd, "%s%s settle", - str_udevadm, verbose ? " --debug" : ""); + snprintf(cmd, cmd_size, "%s%s settle%s%s", + str_udevadm, verbose ? " --debug" : "", + file ? " --exit-if-exists=" : "", file ? file : ""); if (verbose) printf ("%s\n", cmd); r = system (cmd); @@ -1227,6 +1232,13 @@ udev_settle (void) perror ("system"); else if (!WIFEXITED (r) || WEXITSTATUS (r) != 0) fprintf (stderr, "warning: udevadm command failed\n"); + free (cmd); +} + +void +udev_settle (void) +{ + udev_settle_file (NULL); } char * -- 2.11.0