Author: mjg
Date: Fri Sep 8 06:51:33 2017
New Revision: 323307
URL: https://svnweb.freebsd.org/changeset/base/323307
Log:
namecache: factor out dot lookup into a dedicated function
The intent is to move uncommon cases out of the way.
MFC after: 1 week
Modified:
head/sys/kern/vfs_cache.c
Modified: head/sys/kern/vfs_cache.c
==============================================================================
--- head/sys/kern/vfs_cache.c Fri Sep 8 06:46:24 2017 (r323306)
+++ head/sys/kern/vfs_cache.c Fri Sep 8 06:51:33 2017 (r323307)
@@ -1073,6 +1073,42 @@ cache_lookup_unlock(struct rwlock *blp, struct mtx *vl
}
}
+static int __noinline
+cache_lookup_dot(struct vnode *dvp, struct vnode **vpp, struct componentname
*cnp,
+ struct timespec *tsp, int *ticksp)
+{
+ int ltype;
+
+ *vpp = dvp;
+ CTR2(KTR_VFS, "cache_lookup(%p, %s) found via .",
+ dvp, cnp->cn_nameptr);
+ counter_u64_add(dothits, 1);
+ SDT_PROBE3(vfs, namecache, lookup, hit, dvp, ".", *vpp);
+ if (tsp != NULL)
+ timespecclear(tsp);
+ if (ticksp != NULL)
+ *ticksp = ticks;
+ vrefact(*vpp);
+ /*
+ * When we lookup "." we still can be asked to lock it
+ * differently...
+ */
+ ltype = cnp->cn_lkflags & LK_TYPE_MASK;
+ if (ltype != VOP_ISLOCKED(*vpp)) {
+ if (ltype == LK_EXCLUSIVE) {
+ vn_lock(*vpp, LK_UPGRADE | LK_RETRY);
+ if ((*vpp)->v_iflag & VI_DOOMED) {
+ /* forced unmount */
+ vrele(*vpp);
+ *vpp = NULL;
+ return (ENOENT);
+ }
+ } else
+ vn_lock(*vpp, LK_DOWNGRADE | LK_RETRY);
+ }
+ return (-1);
+}
+
/*
* Lookup an entry in the cache
*
@@ -1111,36 +1147,8 @@ retry:
counter_u64_add(numcalls, 1);
if (cnp->cn_nameptr[0] == '.') {
- if (cnp->cn_namelen == 1) {
- *vpp = dvp;
- CTR2(KTR_VFS, "cache_lookup(%p, %s) found via .",
- dvp, cnp->cn_nameptr);
- counter_u64_add(dothits, 1);
- SDT_PROBE3(vfs, namecache, lookup, hit, dvp, ".", *vpp);
- if (tsp != NULL)
- timespecclear(tsp);
- if (ticksp != NULL)
- *ticksp = ticks;
- vrefact(*vpp);
- /*
- * When we lookup "." we still can be asked to lock it
- * differently...
- */
- ltype = cnp->cn_lkflags & LK_TYPE_MASK;
- if (ltype != VOP_ISLOCKED(*vpp)) {
- if (ltype == LK_EXCLUSIVE) {
- vn_lock(*vpp, LK_UPGRADE | LK_RETRY);
- if ((*vpp)->v_iflag & VI_DOOMED) {
- /* forced unmount */
- vrele(*vpp);
- *vpp = NULL;
- return (ENOENT);
- }
- } else
- vn_lock(*vpp, LK_DOWNGRADE | LK_RETRY);
- }
- return (-1);
- }
+ if (cnp->cn_namelen == 1)
+ return (cache_lookup_dot(dvp, vpp, cnp, tsp, ticksp));
if (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.') {
counter_u64_add(dotdothits, 1);
dvlp2 = NULL;
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