cache: factor dotdot lookup out of cache_lookup
Tested by: pho
This commit is contained in:
mjg
parent
4c8927672d
commit
b05f7ca250
@ -1273,14 +1273,10 @@ cache_zap_wlocked_bucket_kl(struct namecache *ncp, struct rwlock *blp,
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}
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static void
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cache_lookup_unlock(struct rwlock *blp, struct mtx *vlp)
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cache_lookup_unlock(struct rwlock *blp)
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{
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if (blp != NULL) {
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rw_runlock(blp);
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} else {
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mtx_unlock(vlp);
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}
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rw_runlock(blp);
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}
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static int __noinline
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@ -1319,6 +1315,111 @@ cache_lookup_dot(struct vnode *dvp, struct vnode **vpp, struct componentname *cn
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return (-1);
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}
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static __noinline int
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cache_remove_cnp(struct vnode *dvp, struct componentname *cnp);
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static int __noinline
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cache_lookup_dotdot(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp,
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struct timespec *tsp, int *ticksp)
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{
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struct namecache_ts *ncp_ts;
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struct namecache *ncp;
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struct mtx *dvlp;
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enum vgetstate vs;
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int error, ltype;
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bool whiteout;
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MPASS((cnp->cn_flags & ISDOTDOT) != 0);
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if ((cnp->cn_flags & MAKEENTRY) == 0) {
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cache_remove_cnp(dvp, cnp);
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return (0);
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}
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counter_u64_add(dotdothits, 1);
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retry:
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dvlp = VP2VNODELOCK(dvp);
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mtx_lock(dvlp);
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ncp = dvp->v_cache_dd;
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if (ncp == NULL) {
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SDT_PROBE3(vfs, namecache, lookup, miss, dvp,
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"..", NULL);
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mtx_unlock(dvlp);
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return (0);
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}
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if ((ncp->nc_flag & NCF_ISDOTDOT) != 0) {
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if (ncp->nc_flag & NCF_NEGATIVE)
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*vpp = NULL;
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else
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*vpp = ncp->nc_vp;
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} else
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*vpp = ncp->nc_dvp;
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/* Return failure if negative entry was found. */
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if (*vpp == NULL)
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goto negative_success;
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CTR3(KTR_VFS, "cache_lookup(%p, %s) found %p via ..",
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dvp, cnp->cn_nameptr, *vpp);
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SDT_PROBE3(vfs, namecache, lookup, hit, dvp, "..",
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*vpp);
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cache_out_ts(ncp, tsp, ticksp);
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if ((ncp->nc_flag & (NCF_ISDOTDOT | NCF_DTS)) ==
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NCF_DTS && tsp != NULL) {
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ncp_ts = __containerof(ncp, struct namecache_ts, nc_nc);
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*tsp = ncp_ts->nc_dotdottime;
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}
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/*
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* On success we return a locked and ref'd vnode as per the lookup
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* protocol.
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*/
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MPASS(dvp != *vpp);
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ltype = 0; /* silence gcc warning */
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ltype = VOP_ISLOCKED(dvp);
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VOP_UNLOCK(dvp);
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vs = vget_prep(*vpp);
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mtx_unlock(dvlp);
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error = vget_finish(*vpp, cnp->cn_lkflags, vs);
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vn_lock(dvp, ltype | LK_RETRY);
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if (VN_IS_DOOMED(dvp)) {
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if (error == 0)
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vput(*vpp);
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*vpp = NULL;
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return (ENOENT);
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}
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if (error) {
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*vpp = NULL;
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goto retry;
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}
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if ((cnp->cn_flags & ISLASTCN) &&
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(cnp->cn_lkflags & LK_TYPE_MASK) == LK_EXCLUSIVE) {
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ASSERT_VOP_ELOCKED(*vpp, "cache_lookup");
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}
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return (-1);
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negative_success:
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if (__predict_false(cnp->cn_nameiop == CREATE)) {
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counter_u64_add(numnegzaps, 1);
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error = cache_zap_locked_vnode(ncp, dvp);
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if (__predict_false(error != 0)) {
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zap_and_exit_bucket_fail2++;
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cache_maybe_yield();
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goto retry;
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}
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cache_free(ncp);
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return (0);
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}
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SDT_PROBE2(vfs, namecache, lookup, hit__negative, dvp, ncp->nc_name);
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cache_out_ts(ncp, tsp, ticksp);
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counter_u64_add(numneghits, 1);
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whiteout = (ncp->nc_flag & NCF_WHITE);
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cache_negative_hit(ncp);
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mtx_unlock(dvlp);
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if (whiteout)
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cnp->cn_flags |= ISWHITEOUT;
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return (ENOENT);
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}
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static __noinline int
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cache_remove_cnp(struct vnode *dvp, struct componentname *cnp)
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{
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@ -1441,14 +1542,12 @@ int
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cache_lookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp,
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struct timespec *tsp, int *ticksp)
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{
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struct namecache_ts *ncp_ts;
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struct namecache *ncp;
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struct negstate *negstate;
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struct rwlock *blp;
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struct mtx *dvlp;
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uint32_t hash;
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enum vgetstate vs;
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int error, ltype;
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int error;
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bool try_smr, doing_smr, whiteout;
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#ifdef DEBUG_CACHE
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@ -1458,8 +1557,14 @@ cache_lookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp,
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}
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#endif
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if (__predict_false(cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.'))
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return (cache_lookup_dot(dvp, vpp, cnp, tsp, ticksp));
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if (__predict_false(cnp->cn_nameptr[0] == '.')) {
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if (cnp->cn_namelen == 1)
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return (cache_lookup_dot(dvp, vpp, cnp, tsp, ticksp));
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if (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.')
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return (cache_lookup_dotdot(dvp, vpp, cnp, tsp, ticksp));
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}
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MPASS((cnp->cn_flags & ISDOTDOT) == 0);
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if ((cnp->cn_flags & MAKEENTRY) == 0) {
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cache_remove_cnp(dvp, cnp);
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@ -1472,42 +1577,7 @@ cache_lookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp,
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retry:
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doing_smr = false;
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blp = NULL;
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dvlp = NULL;
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error = 0;
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if (cnp->cn_namelen == 2 &&
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cnp->cn_nameptr[0] == '.' && cnp->cn_nameptr[1] == '.') {
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counter_u64_add(dotdothits, 1);
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dvlp = VP2VNODELOCK(dvp);
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mtx_lock(dvlp);
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ncp = dvp->v_cache_dd;
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if (ncp == NULL) {
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SDT_PROBE3(vfs, namecache, lookup, miss, dvp,
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"..", NULL);
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mtx_unlock(dvlp);
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return (0);
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}
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if ((ncp->nc_flag & NCF_ISDOTDOT) != 0) {
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if (ncp->nc_flag & NCF_NEGATIVE)
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*vpp = NULL;
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else
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*vpp = ncp->nc_vp;
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} else
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*vpp = ncp->nc_dvp;
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/* Return failure if negative entry was found. */
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if (*vpp == NULL)
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goto negative_success;
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CTR3(KTR_VFS, "cache_lookup(%p, %s) found %p via ..",
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dvp, cnp->cn_nameptr, *vpp);
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SDT_PROBE3(vfs, namecache, lookup, hit, dvp, "..",
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*vpp);
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cache_out_ts(ncp, tsp, ticksp);
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if ((ncp->nc_flag & (NCF_ISDOTDOT | NCF_DTS)) ==
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NCF_DTS && tsp != NULL) {
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ncp_ts = __containerof(ncp, struct namecache_ts, nc_nc);
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*tsp = ncp_ts->nc_dotdottime;
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}
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goto success;
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}
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hash = cache_get_hash(cnp->cn_nameptr, cnp->cn_namelen, dvp);
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retry_hashed:
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@ -1549,17 +1619,11 @@ retry_hashed:
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SDT_PROBE3(vfs, namecache, lookup, hit, dvp, ncp->nc_name,
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*vpp);
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cache_out_ts(ncp, tsp, ticksp);
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success:
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/*
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* On success we return a locked and ref'd vnode as per the lookup
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* protocol.
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*/
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MPASS(dvp != *vpp);
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ltype = 0; /* silence gcc warning */
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if (cnp->cn_flags & ISDOTDOT) {
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ltype = VOP_ISLOCKED(dvp);
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VOP_UNLOCK(dvp);
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}
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if (doing_smr) {
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if (!cache_ncp_canuse(ncp)) {
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vfs_smr_exit();
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@ -1574,18 +1638,9 @@ success:
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}
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} else {
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vs = vget_prep(*vpp);
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cache_lookup_unlock(blp, dvlp);
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cache_lookup_unlock(blp);
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}
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error = vget_finish(*vpp, cnp->cn_lkflags, vs);
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if (cnp->cn_flags & ISDOTDOT) {
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vn_lock(dvp, ltype | LK_RETRY);
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if (VN_IS_DOOMED(dvp)) {
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if (error == 0)
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vput(*vpp);
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*vpp = NULL;
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return (ENOENT);
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}
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}
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if (error) {
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*vpp = NULL;
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goto retry;
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@ -1598,10 +1653,17 @@ success:
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negative_success:
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/* We found a negative match, and want to create it, so purge */
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if (cnp->cn_nameiop == CREATE) {
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if (__predict_false(cnp->cn_nameiop == CREATE)) {
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MPASS(!doing_smr);
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counter_u64_add(numnegzaps, 1);
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goto zap_and_exit;
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error = cache_zap_rlocked_bucket(ncp, cnp, hash, blp);
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if (__predict_false(error != 0)) {
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zap_and_exit_bucket_fail2++;
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cache_maybe_yield();
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goto retry;
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}
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cache_free(ncp);
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return (0);
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}
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SDT_PROBE2(vfs, namecache, lookup, hit__negative, dvp, ncp->nc_name);
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@ -1623,25 +1685,11 @@ negative_success:
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vfs_smr_exit();
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} else {
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cache_negative_hit(ncp);
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cache_lookup_unlock(blp, dvlp);
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cache_lookup_unlock(blp);
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}
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if (whiteout)
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cnp->cn_flags |= ISWHITEOUT;
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return (ENOENT);
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zap_and_exit:
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MPASS(!doing_smr);
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if (blp != NULL)
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error = cache_zap_rlocked_bucket(ncp, cnp, hash, blp);
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else
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error = cache_zap_locked_vnode(ncp, dvp);
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if (__predict_false(error != 0)) {
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zap_and_exit_bucket_fail2++;
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cache_maybe_yield();
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goto retry;
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}
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cache_free(ncp);
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return (0);
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}
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struct celockstate {
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