[Libguestfs] [PATCH v3 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 | 31 ++++++++++++++++++++++++------- 2 files changed, 26 insertions(+), 7 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..635f5b1d2 100644 --- a/daemon/guestfsd.c +++ b/daemon/guestfsd.c @@ -63,6 +63,8 @@ #include "daemon.h" +#define MAX_ARGS 64 + GUESTFSD_EXT_CMD(str_udevadm, udevadm); GUESTFSD_EXT_CMD(str_uuidgen, uuidgen); @@ -1213,22 +1215,37 @@ random_name (char *template) * fussed if it fails. */ void -udev_settle (void) +udev_settle_file (const char *file) { - char cmd[80]; + const char *argv[MAX_ARGS]; + CLEANUP_FREE char *err = NULL; + size_t i = 0; int r; - snprintf (cmd, sizeof cmd, "%s%s settle", - str_udevadm, verbose ? " --debug" : ""); + ADD_ARG (argv, i, str_udevadm); if (verbose) - printf ("%s\n", cmd); - r = system (cmd); + ADD_ARG (argv, i, "--debug"); + + ADD_ARG (argv, i, "settle"); + if (file) { + ADD_ARG (argv, i, "-E"); + ADD_ARG (argv, i, file); + } + ADD_ARG (argv, i, NULL); + + r = commandrv (NULL, &err, argv); if (r == -1) - perror ("system"); + fprintf (stderr, "%s\n", err); else if (!WIFEXITED (r) || WEXITSTATUS (r) != 0) fprintf (stderr, "warning: udevadm command failed\n"); } +void +udev_settle (void) +{ + udev_settle_file (NULL); +} + char * get_random_uuid (void) { -- 2.11.0