This uses roughly 10% cycles of the sscanf-based implementation.
Improves: ee8888f0 "multipath-tools: improve processing efficiency..."
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
libmultipath/uevent.c | 37 +++++++++++++++++++++++--------------
1 file changed, 23 insertions(+), 14 deletions(-)
diff --git a/libmultipath/uevent.c b/libmultipath/uevent.c
index 6e2527bd..367e129a 100644
--- a/libmultipath/uevent.c
+++ b/libmultipath/uevent.c
@@ -143,26 +143,35 @@ uevent_need_merge(void)
return need_merge;
}
+static bool
+uevent_can_discard_by_devpath(const char *devpath)
+{
+ static const char BLOCK[] = "/block/";
+ const char *tmp = strstr(devpath, BLOCK);
+
+ if (tmp == NULL) {
+ condlog(4, "no /block/ in '%s'", devpath);
+ return true;
+ }
+ tmp += sizeof(BLOCK) - 1;
+ if (*tmp == '\0')
+ /* just ".../block/" - discard */
+ return true;
+ /*
+ * If there are more path elements after ".../block/xyz",
+ * it's a partition - discard it; but don't discard ".../block/sda/".
+ */
+ tmp = strchr(tmp, '/');
+ return tmp != NULL && *(tmp + 1) != '\0';
+}
+
bool
uevent_can_discard(struct uevent *uev)
{
- char *tmp;
- char a[11], b[11];
struct config * conf;
- /*
- * keep only block devices, discard partitions
- */
- tmp = strstr(uev->devpath, "/block/");
- if (tmp == NULL){
- condlog(4, "no /block/ in '%s'", uev->devpath);
+ if (uevent_can_discard_by_devpath(uev->devpath))
return true;
- }
- if (sscanf(tmp, "/block/%10s", a) != 1 ||
- sscanf(tmp, "/block/%10[^/]/%10s", a, b) == 2) {
- condlog(4, "discard event on %s", uev->devpath);
- return true;
- }
/*
* do not filter dm devices by devnode
--
2.12.0
--
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