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diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
@@ -585,6 +585,24 @@
return (&vnodelocks[(((uintptr_t)(vp) >> 8) & ncvnodehash)]);
}
+/*
+ * Search the hash table for a namecache entry. Either the corresponding bucket
+ * must be locked, or the caller must be in an SMR read section.
+ */
+static struct namecache *
+cache_ncp_find(struct vnode *dvp, struct componentname *cnp, uint32_t hash)
+{
+ struct namecache *ncp;
+
+ KASSERT(mtx_owned(HASH2BUCKETLOCK(hash)) || VFS_SMR_ENTERED(),
+ ("%s: hash %u not locked", __func__, hash));
+ CK_SLIST_FOREACH(ncp, NCHHASH(hash), nc_hash) {
+ if (cache_ncp_match(ncp, dvp, cnp))
+ break;
+ }
+ return (ncp);
+}
+
static void
cache_out_ts(struct namecache *ncp, struct timespec *tsp, int *ticksp)
{
@@ -1877,12 +1895,7 @@
goto out_no_entry;
mtx_lock(blp);
-
- CK_SLIST_FOREACH(ncp, (NCHHASH(hash)), nc_hash) {
- if (cache_ncp_match(ncp, dvp, cnp))
- break;
- }
-
+ ncp = cache_ncp_find(dvp, cnp, hash);
if (ncp == NULL) {
mtx_unlock(blp);
goto out_no_entry;
@@ -2078,11 +2091,7 @@
blp = HASH2BUCKETLOCK(hash);
mtx_lock(blp);
- CK_SLIST_FOREACH(ncp, (NCHHASH(hash)), nc_hash) {
- if (cache_ncp_match(ncp, dvp, cnp))
- break;
- }
-
+ ncp = cache_ncp_find(dvp, cnp, hash);
if (__predict_false(ncp == NULL)) {
mtx_unlock(blp);
SDT_PROBE2(vfs, namecache, lookup, miss, dvp, cnp->cn_nameptr);
@@ -2172,11 +2181,7 @@
hash = cache_get_hash(cnp->cn_nameptr, cnp->cn_namelen, dvp);
vfs_smr_enter();
- CK_SLIST_FOREACH(ncp, (NCHHASH(hash)), nc_hash) {
- if (cache_ncp_match(ncp, dvp, cnp))
- break;
- }
-
+ ncp = cache_ncp_find(dvp, cnp, hash);
if (__predict_false(ncp == NULL)) {
vfs_smr_exit();
SDT_PROBE2(vfs, namecache, lookup, miss, dvp, cnp->cn_nameptr);
@@ -2494,7 +2499,6 @@
struct celockstate cel;
struct namecache *ncp, *n2, *ndd;
struct namecache_ts *ncp_ts;
- struct nchashhead *ncpp;
uint32_t hash;
int flag;
int len;
@@ -2571,45 +2575,46 @@
* with this name. This can happen with concurrent lookups of
* the same path name.
*/
- ncpp = NCHHASH(hash);
- CK_SLIST_FOREACH(n2, ncpp, nc_hash) {
- if (cache_ncp_match(n2, dvp, cnp)) {
- MPASS(cache_ncp_canuse(n2));
- if ((n2->nc_flag & NCF_NEGATIVE) != 0)
- KASSERT(vp == NULL,
- ("%s: found entry pointing to a different vnode (%p != %p) ; name [%s]",
- __func__, NULL, vp, cnp->cn_nameptr));
- else
- KASSERT(n2->nc_vp == vp,
- ("%s: found entry pointing to a different vnode (%p != %p) ; name [%s]",
- __func__, n2->nc_vp, vp, cnp->cn_nameptr));
- /*
- * Entries are supposed to be immutable unless in the
- * process of getting destroyed. Accommodating for
- * changing timestamps is possible but not worth it.
- * This should be harmless in terms of correctness, in
- * the worst case resulting in an earlier expiration.
- * Alternatively, the found entry can be replaced
- * altogether.
- */
- MPASS((n2->nc_flag & (NCF_TS | NCF_DTS)) == (ncp->nc_flag & (NCF_TS | NCF_DTS)));
+ n2 = cache_ncp_find(dvp, cnp, hash);
+ if (n2 != NULL) {
+ MPASS(cache_ncp_canuse(n2));
+ if ((n2->nc_flag & NCF_NEGATIVE) != 0)
+ KASSERT(vp == NULL,
+ ("%s: found entry pointing to a different vnode "
+ "(%p != %p); name [%s]",
+ __func__, NULL, vp, cnp->cn_nameptr));
+ else
+ KASSERT(n2->nc_vp == vp,
+ ("%s: found entry pointing to a different vnode "
+ "(%p != %p); name [%s]",
+ __func__, n2->nc_vp, vp, cnp->cn_nameptr));
+ /*
+ * Entries are supposed to be immutable unless in the
+ * process of getting destroyed. Accommodating for
+ * changing timestamps is possible but not worth it.
+ * This should be harmless in terms of correctness, in
+ * the worst case resulting in an earlier expiration.
+ * Alternatively, the found entry can be replaced
+ * altogether.
+ */
+ MPASS((n2->nc_flag & (NCF_TS | NCF_DTS)) ==
+ (ncp->nc_flag & (NCF_TS | NCF_DTS)));
#if 0
- if (tsp != NULL) {
- KASSERT((n2->nc_flag & NCF_TS) != 0,
- ("no NCF_TS"));
- n2_ts = __containerof(n2, struct namecache_ts, nc_nc);
- n2_ts->nc_time = ncp_ts->nc_time;
- n2_ts->nc_ticks = ncp_ts->nc_ticks;
- if (dtsp != NULL) {
- n2_ts->nc_dotdottime = ncp_ts->nc_dotdottime;
- n2_ts->nc_nc.nc_flag |= NCF_DTS;
- }
+ if (tsp != NULL) {
+ KASSERT((n2->nc_flag & NCF_TS) != 0,
+ ("no NCF_TS"));
+ n2_ts = __containerof(n2, struct namecache_ts, nc_nc);
+ n2_ts->nc_time = ncp_ts->nc_time;
+ n2_ts->nc_ticks = ncp_ts->nc_ticks;
+ if (dtsp != NULL) {
+ n2_ts->nc_dotdottime = ncp_ts->nc_dotdottime;
+ n2_ts->nc_nc.nc_flag |= NCF_DTS;
}
-#endif
- SDT_PROBE3(vfs, namecache, enter, duplicate, dvp, ncp->nc_name,
- vp);
- goto out_unlock_free;
}
+#endif
+ SDT_PROBE3(vfs, namecache, enter, duplicate, dvp, ncp->nc_name,
+ vp);
+ goto out_unlock_free;
}
if (flag == NCF_ISDOTDOT) {
@@ -2675,7 +2680,7 @@
* Insert the new namecache entry into the appropriate chain
* within the cache entries table.
*/
- CK_SLIST_INSERT_HEAD(ncpp, ncp, nc_hash);
+ CK_SLIST_INSERT_HEAD(NCHHASH(hash), ncp, nc_hash);
atomic_thread_fence_rel();
/*
@@ -3105,12 +3110,10 @@
return;
blp = HASH2BUCKETLOCK(hash);
mtx_lock(blp);
- CK_SLIST_FOREACH(ncp, (NCHHASH(hash)), nc_hash) {
- if (cache_ncp_match(ncp, dvp, cnp)) {
- if (ncp->nc_vp != vp)
- panic("%s: mismatch (%p != %p); ncp %p [%s] dvp %p\n",
- __func__, vp, ncp->nc_vp, ncp, ncp->nc_name, ncp->nc_dvp);
- }
+ ncp = cache_ncp_find(dvp, cnp, hash);
+ if (ncp != NULL && ncp->nc_vp != vp) {
+ panic("%s: mismatch (%p != %p); ncp %p [%s] dvp %p\n",
+ __func__, vp, ncp->nc_vp, ncp, ncp->nc_name, ncp->nc_dvp);
}
mtx_unlock(blp);
}
@@ -5554,11 +5557,7 @@
MPASS(!cache_fpl_isdotdot(cnp));
- CK_SLIST_FOREACH(ncp, (NCHHASH(hash)), nc_hash) {
- if (cache_ncp_match(ncp, dvp, cnp))
- break;
- }
-
+ ncp = cache_ncp_find(dvp, cnp, hash);
if (__predict_false(ncp == NULL)) {
return (cache_fplookup_noentry(fpl));
}
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -1195,6 +1195,7 @@
#define vfs_smr_exit() smr_exit(VFS_SMR())
#define vfs_smr_synchronize() smr_synchronize(VFS_SMR())
#define vfs_smr_entered_load(ptr) smr_entered_load((ptr), VFS_SMR())
+#define VFS_SMR_ENTERED() SMR_ENTERED(VFS_SMR())
#define VFS_SMR_ASSERT_ENTERED() SMR_ASSERT_ENTERED(VFS_SMR())
#define VFS_SMR_ASSERT_NOT_ENTERED() SMR_ASSERT_NOT_ENTERED(VFS_SMR())
#define VFS_SMR_ZONE_SET(zone) uma_zone_set_smr((zone), VFS_SMR())

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