mdev: support for serializing hotplug
function old new delta
mdev_main 503 647 +144
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index c61521c..8968e45 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -374,8 +374,6 @@
int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int mdev_main(int argc UNUSED_PARAM, char **argv)
{
- char *action;
- char *env_path;
RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
/* We can be called as hotplug helper */
@@ -417,8 +415,14 @@
ACTION_RECURSE | ACTION_FOLLOWLINKS,
fileAction, dirAction, temp, 0);
} else {
+ char *seq;
+ char *action;
+ char *env_path;
+ char seqbuf[sizeof(int)*3 + 2];
+ int seqlen = seqlen; /* for compiler */
+
/* Hotplug:
- * env ACTION=... DEVPATH=... mdev
+ * env ACTION=... DEVPATH=... [SEQNUM=...] mdev
* ACTION can be "add" or "remove"
* DEVPATH is like "/block/sda" or "/class/input/mice"
*/
@@ -427,6 +431,23 @@
if (!action || !env_path)
bb_show_usage();
+ seq = getenv("SEQNUM");
+ if (seq) {
+ int timeout = 2000 / 32;
+ do {
+ seqlen = open_read_close("mdev.seq", seqbuf, sizeof(seqbuf-1));
+ if (seqlen < 0)
+ break;
+ seqbuf[seqlen] = '\0';
+ if (seqbuf[0] == '\n' /* seed file? */
+ || strcmp(seq, seqbuf) == 0 /* correct idx? */
+ ) {
+ break;
+ }
+ usleep(32*1000);
+ } while (--timeout);
+ }
+
snprintf(temp, PATH_MAX, "/sys%s", env_path);
if (!strcmp(action, "remove"))
make_device(temp, 1);
@@ -439,6 +460,10 @@
load_firmware(fw, temp);
}
}
+
+ if (seq && seqlen >= 0) {
+ xopen_xwrite_close("mdev.seq", utoa(xatou(seq) + 1));
+ }
}
if (ENABLE_FEATURE_CLEAN_UP)