git: 8a44ccd05889 - stable/13 - cache: store vnodes in local vars in cache_zap_locked

[Mateusz Guzik]

The branch stable/13 has been updated by mjg:

URL: https://cgit.FreeBSD.org/src/commit/?id=8a44ccd0588966b5687c30644e83ab1eef9683e3

commit 8a44ccd0588966b5687c30644e83ab1eef9683e3
Author:     Mateusz Guzik <mjg at FreeBSD.org>
AuthorDate: 2021-01-23 19:41:40 +0000
Commit:     Mateusz Guzik <mjg at FreeBSD.org>
CommitDate: 2021-02-01 12:39:16 +0000

    cache: store vnodes in local vars in cache_zap_locked
    
    (cherry picked from commit ffcf8f97f8a8fb92689793003acabc0a2fe97af4)
---
 sys/kern/vfs_cache.c | 34 ++++++++++++++++++----------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index e3098ac7c5d5..9d5b18aa4132 100644
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
@@ -1422,10 +1422,14 @@ static void
 cache_zap_locked(struct namecache *ncp)
 {
 	struct nchashhead *ncpp;
+	struct vnode *dvp, *vp;
+
+	dvp = ncp->nc_dvp;
+	vp = ncp->nc_vp;
 
 	if (!(ncp->nc_flag & NCF_NEGATIVE))
-		cache_assert_vnode_locked(ncp->nc_vp);
-	cache_assert_vnode_locked(ncp->nc_dvp);
+		cache_assert_vnode_locked(vp);
+	cache_assert_vnode_locked(dvp);
 	cache_assert_bucket_locked(ncp);
 
 	cache_ncp_invalidate(ncp);
@@ -1433,28 +1437,26 @@ cache_zap_locked(struct namecache *ncp)
 	ncpp = NCP2BUCKET(ncp);
 	CK_SLIST_REMOVE(ncpp, ncp, namecache, nc_hash);
 	if (!(ncp->nc_flag & NCF_NEGATIVE)) {
-		SDT_PROBE3(vfs, namecache, zap, done, ncp->nc_dvp,
-		    ncp->nc_name, ncp->nc_vp);
-		TAILQ_REMOVE(&ncp->nc_vp->v_cache_dst, ncp, nc_dst);
-		if (ncp == ncp->nc_vp->v_cache_dd) {
-			vn_seqc_write_begin_unheld(ncp->nc_vp);
-			ncp->nc_vp->v_cache_dd = NULL;
-			vn_seqc_write_end(ncp->nc_vp);
+		SDT_PROBE3(vfs, namecache, zap, done, dvp, ncp->nc_name, vp);
+		TAILQ_REMOVE(&vp->v_cache_dst, ncp, nc_dst);
+		if (ncp == vp->v_cache_dd) {
+			vn_seqc_write_begin_unheld(vp);
+			vp->v_cache_dd = NULL;
+			vn_seqc_write_end(vp);
 		}
 	} else {
-		SDT_PROBE2(vfs, namecache, zap_negative, done, ncp->nc_dvp,
-		    ncp->nc_name);
+		SDT_PROBE2(vfs, namecache, zap_negative, done, dvp, ncp->nc_name);
 		cache_neg_remove(ncp);
 	}
 	if (ncp->nc_flag & NCF_ISDOTDOT) {
-		if (ncp == ncp->nc_dvp->v_cache_dd) {
-			vn_seqc_write_begin_unheld(ncp->nc_dvp);
-			ncp->nc_dvp->v_cache_dd = NULL;
-			vn_seqc_write_end(ncp->nc_dvp);
+		if (ncp == dvp->v_cache_dd) {
+			vn_seqc_write_begin_unheld(dvp);
+			dvp->v_cache_dd = NULL;
+			vn_seqc_write_end(dvp);
 		}
 	} else {
 		LIST_REMOVE(ncp, nc_src);
-		if (LIST_EMPTY(&ncp->nc_dvp->v_cache_src)) {
+		if (LIST_EMPTY(&dvp->v_cache_src)) {
 			ncp->nc_flag |= NCF_DVDROP;
 		}
 	}