From 5e99212d36ad1e4c9b40ad41fb9b1b10e579e567 Mon Sep 17 00:00:00 2001 From: Rick Macklem Date: Sat, 3 Mar 2012 01:06:54 +0000 Subject: [PATCH] Post r230394, the Lookup RPC counts for both NFS clients increased significantly. Upon investigation this was caused by name cache misses for lookups of "..". For name cache entries for non-".." directories, the cache entry serves double duty. It maps both the named directory plus ".." for the parent of the directory. As such, two ctime values (one for each of the directory and its parent) need to be saved in the name cache entry. This patch adds an entry for ctime of the parent directory to the name cache. It also adds an additional uma zone for large entries with this time value, in order to minimize memory wastage. As well, it fixes a couple of cases where the mtime of the parent directory was being saved instead of ctime for positive name cache entries. With this patch, Lookup RPC counts return to values similar to pre-r230394 kernels. Reported by: bde Discussed with: kib Reviewed by: jhb MFC after: 2 weeks --- sys/fs/nfsclient/nfs_clrpcops.c | 13 ++++++++-- sys/fs/nfsclient/nfs_clvnops.c | 43 ++++++++++++++++-------------- sys/kern/vfs_cache.c | 46 +++++++++++++++++++++++++++++---- sys/nfsclient/nfs_vnops.c | 26 +++++++++++-------- sys/sys/vnode.h | 5 ++-- 5 files changed, 93 insertions(+), 40 deletions(-) diff --git a/sys/fs/nfsclient/nfs_clrpcops.c b/sys/fs/nfsclient/nfs_clrpcops.c index 86a0601f8aa7..2562c6157045 100644 --- a/sys/fs/nfsclient/nfs_clrpcops.c +++ b/sys/fs/nfsclient/nfs_clrpcops.c @@ -2951,10 +2951,12 @@ nfsrpc_readdirplus(vnode_t vp, struct uio *uiop, nfsuint64 *cookiep, nfsattrbit_t attrbits, dattrbits; size_t tresid; u_int32_t *tl2 = NULL, fakefileno = 0xffffffff, rderr; + struct timespec dctime; KASSERT(uiop->uio_iovcnt == 1 && (uio_uio_resid(uiop) & (DIRBLKSIZ - 1)) == 0, ("nfs readdirplusrpc bad uio")); + timespecclear(&dctime); *attrflagp = 0; if (eofp != NULL) *eofp = 0; @@ -2997,6 +2999,7 @@ nfsrpc_readdirplus(vnode_t vp, struct uio *uiop, nfsuint64 *cookiep, #endif if (error) return (error); + dctime = nfsva.na_ctime; dotfileid = nfsva.na_fileid; NFSCL_REQSTART(nd, NFSPROC_LOOKUPP, vp); NFSM_BUILD(tl, u_int32_t *, 2 * NFSX_UNSIGNED); @@ -3134,6 +3137,8 @@ nfsrpc_readdirplus(vnode_t vp, struct uio *uiop, nfsuint64 *cookiep, error = nd->nd_repstat; goto nfsmout; } + if ((nd->nd_flag & ND_NFSV3) != 0 && *attrflagp != 0) + dctime = nap->na_ctime; NFSM_DISSECT(tl, u_int32_t *, 3 * NFSX_UNSIGNED); NFSLOCKNODE(dnp); dnp->n_cookieverf.nfsuquad[0] = *tl++; @@ -3316,10 +3321,14 @@ nfsrpc_readdirplus(vnode_t vp, struct uio *uiop, nfsuint64 *cookiep, vtonfs_dtype(np->n_vattr.na_type); ndp->ni_vp = newvp; NFSCNHASH(cnp, HASHINIT); - if (cnp->cn_namelen <= NCHNAMLEN) { + if (cnp->cn_namelen <= NCHNAMLEN && + (newvp->v_type != VDIR || + dctime.tv_sec != 0)) { cache_enter_time(ndp->ni_dvp, ndp->ni_vp, cnp, - &nfsva.na_ctime); + &nfsva.na_ctime, + newvp->v_type != VDIR ? NULL : + &dctime); } if (unlocknewvp) vput(newvp); diff --git a/sys/fs/nfsclient/nfs_clvnops.c b/sys/fs/nfsclient/nfs_clvnops.c index f92d19330e10..57c687c93003 100644 --- a/sys/fs/nfsclient/nfs_clvnops.c +++ b/sys/fs/nfsclient/nfs_clvnops.c @@ -1172,7 +1172,7 @@ nfs_lookup(struct vop_lookup_args *ap) &dnfsva.na_mtime, ==)) { mtx_unlock(&np->n_mtx); cache_enter_time(dvp, NULL, cnp, - &dnfsva.na_mtime); + &dnfsva.na_mtime, NULL); } else mtx_unlock(&np->n_mtx); } @@ -1271,9 +1271,10 @@ nfs_lookup(struct vop_lookup_args *ap) if (cnp->cn_nameiop != LOOKUP && (flags & ISLASTCN)) cnp->cn_flags |= SAVENAME; if ((cnp->cn_flags & MAKEENTRY) && - (cnp->cn_nameiop != DELETE || !(flags & ISLASTCN)) && attrflag) { - cache_enter_time(dvp, newvp, cnp, &nfsva.na_ctime); - } + (cnp->cn_nameiop != DELETE || !(flags & ISLASTCN)) && + attrflag != 0 && (newvp->v_type != VDIR || dattrflag != 0)) + cache_enter_time(dvp, newvp, cnp, &nfsva.na_ctime, + newvp->v_type != VDIR ? NULL : &dnfsva.na_ctime); *vpp = newvp; return (0); } @@ -1591,7 +1592,8 @@ nfs_create(struct vop_create_args *ap) } if (!error) { if ((cnp->cn_flags & MAKEENTRY) && attrflag) - cache_enter_time(dvp, newvp, cnp, &nfsva.na_ctime); + cache_enter_time(dvp, newvp, cnp, &nfsva.na_ctime, + NULL); *ap->a_vpp = newvp; } else if (NFS_ISV4(dvp)) { error = nfscl_maperr(cnp->cn_thread, error, vap->va_uid, @@ -1966,8 +1968,8 @@ nfs_link(struct vop_link_args *ap) * must care about lookup caching hit rate, so... */ if (VFSTONFS(vp->v_mount)->nm_negnametimeo != 0 && - (cnp->cn_flags & MAKEENTRY) && dattrflag) { - cache_enter_time(tdvp, vp, cnp, &dnfsva.na_mtime); + (cnp->cn_flags & MAKEENTRY) && attrflag != 0 && error == 0) { + cache_enter_time(tdvp, vp, cnp, &nfsva.na_ctime, NULL); } if (error && NFS_ISV4(vp)) error = nfscl_maperr(cnp->cn_thread, error, (uid_t)0, @@ -2033,21 +2035,21 @@ nfs_symlink(struct vop_symlink_args *ap) if (dattrflag != 0) { mtx_unlock(&dnp->n_mtx); (void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1); - /* - * If negative lookup caching is enabled, I might as well - * add an entry for this node. Not necessary for correctness, - * but if negative caching is enabled, then the system - * must care about lookup caching hit rate, so... - */ - if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 && - (cnp->cn_flags & MAKEENTRY)) { - cache_enter_time(dvp, newvp, cnp, &dnfsva.na_mtime); - } } else { dnp->n_attrstamp = 0; mtx_unlock(&dnp->n_mtx); KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(dvp); } + /* + * If negative lookup caching is enabled, I might as well + * add an entry for this node. Not necessary for correctness, + * but if negative caching is enabled, then the system + * must care about lookup caching hit rate, so... + */ + if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 && + (cnp->cn_flags & MAKEENTRY) && attrflag != 0 && error == 0) { + cache_enter_time(dvp, newvp, cnp, &nfsva.na_ctime, NULL); + } return (error); } @@ -2118,9 +2120,10 @@ nfs_mkdir(struct vop_mkdir_args *ap) * must care about lookup caching hit rate, so... */ if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 && - (cnp->cn_flags & MAKEENTRY) && dattrflag) { - cache_enter_time(dvp, newvp, cnp, &dnfsva.na_mtime); - } + (cnp->cn_flags & MAKEENTRY) && + attrflag != 0 && dattrflag != 0) + cache_enter_time(dvp, newvp, cnp, &nfsva.na_ctime, + &dnfsva.na_ctime); *ap->a_vpp = newvp; } return (error); diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index 1f081baa3ecf..ea481f4c73d5 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -105,6 +105,10 @@ struct namecache { /* * struct namecache_ts repeats struct namecache layout up to the * nc_nlen member. + * struct namecache_ts is used in place of struct namecache when time(s) need + * to be stored. The nc_dotdottime field is used when a cache entry is mapping + * both a non-dotdot directory name plus dotdot for the directory's + * parent. */ struct namecache_ts { LIST_ENTRY(namecache) nc_hash; /* hash chain */ @@ -115,6 +119,7 @@ struct namecache_ts { u_char nc_flag; /* flag bits */ u_char nc_nlen; /* length of name */ struct timespec nc_time; /* timespec provided by fs */ + struct timespec nc_dotdottime; /* dotdot timespec provided by fs */ int nc_ticks; /* ticks value when entry was added */ char nc_name[0]; /* segment name + nul */ }; @@ -125,6 +130,7 @@ struct namecache_ts { #define NCF_WHITE 0x01 #define NCF_ISDOTDOT 0x02 #define NCF_TS 0x04 +#define NCF_DTS 0x08 /* * Name caching works as follows: @@ -190,6 +196,7 @@ RW_SYSINIT(vfscache, &cache_lock, "Name Cache"); static uma_zone_t cache_zone_small; static uma_zone_t cache_zone_small_ts; static uma_zone_t cache_zone_large; +static uma_zone_t cache_zone_large_ts; #define CACHE_PATH_CUTOFF 35 @@ -197,8 +204,12 @@ static struct namecache * cache_alloc(int len, int ts) { - if (len > CACHE_PATH_CUTOFF) - return (uma_zalloc(cache_zone_large, M_WAITOK)); + if (len > CACHE_PATH_CUTOFF) { + if (ts) + return (uma_zalloc(cache_zone_large_ts, M_WAITOK)); + else + return (uma_zalloc(cache_zone_large, M_WAITOK)); + } if (ts) return (uma_zalloc(cache_zone_small_ts, M_WAITOK)); else @@ -218,7 +229,9 @@ cache_free(struct namecache *ncp) uma_zfree(cache_zone_small_ts, ncp); else uma_zfree(cache_zone_small, ncp); - } else + } else if (ts) + uma_zfree(cache_zone_large_ts, ncp); + else uma_zfree(cache_zone_large, ncp); } @@ -521,6 +534,10 @@ cache_lookup(dvp, vpp, cnp, tsp, ticksp) SDT_PROBE(vfs, namecache, lookup, hit, dvp, "..", *vpp, 0, 0); cache_out_ts(ncp, tsp, ticksp); + if ((ncp->nc_flag & (NCF_ISDOTDOT | NCF_DTS)) == + NCF_DTS && tsp != NULL) + *tsp = ((struct namecache_ts *)ncp)-> + nc_dotdottime; goto success; } } @@ -686,11 +703,12 @@ cache_lookup(dvp, vpp, cnp, tsp, ticksp) * Add an entry to the cache. */ void -cache_enter_time(dvp, vp, cnp, tsp) +cache_enter_time(dvp, vp, cnp, tsp, dtsp) struct vnode *dvp; struct vnode *vp; struct componentname *cnp; struct timespec *tsp; + struct timespec *dtsp; { struct namecache *ncp, *n2; struct namecache_ts *n3; @@ -769,6 +787,10 @@ cache_enter_time(dvp, vp, cnp, tsp) n3->nc_time = *tsp; n3->nc_ticks = ticks; n3->nc_flag |= NCF_TS; + if (dtsp != NULL) { + n3->nc_dotdottime = *dtsp; + n3->nc_flag |= NCF_DTS; + } } len = ncp->nc_nlen = cnp->cn_namelen; hash = fnv_32_buf(cnp->cn_nameptr, len, FNV1_32_INIT); @@ -794,6 +816,12 @@ cache_enter_time(dvp, vp, cnp, tsp) ((struct namecache_ts *)ncp)->nc_time; n3->nc_ticks = ((struct namecache_ts *)ncp)->nc_ticks; + if (dtsp != NULL) { + n3->nc_dotdottime = + ((struct namecache_ts *)ncp)-> + nc_dotdottime; + n3->nc_flag |= NCF_DTS; + } } CACHE_WUNLOCK(); cache_free(ncp); @@ -823,6 +851,11 @@ cache_enter_time(dvp, vp, cnp, tsp) ncp->nc_flag |= NCF_WHITE; } else if (vp->v_type == VDIR) { if (flag != NCF_ISDOTDOT) { + /* + * For this case, the cache entry maps both the + * directory name in it and the name ".." for the + * directory's parent. + */ if ((n2 = vp->v_cache_dd) != NULL && (n2->nc_flag & NCF_ISDOTDOT) != 0) cache_zap(n2); @@ -886,6 +919,9 @@ nchinit(void *dummy __unused) sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1, NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_ZINIT); cache_zone_large = uma_zcreate("L VFS Cache", + sizeof(struct namecache) + NAME_MAX + 1, + NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_ZINIT); + cache_zone_large_ts = uma_zcreate("LTS VFS Cache", sizeof(struct namecache_ts) + NAME_MAX + 1, NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_ZINIT); @@ -1382,7 +1418,7 @@ void cache_enter(struct vnode *dvp, struct vnode *vp, struct componentname *cnp) { - cache_enter_time(dvp, vp, cnp, NULL); + cache_enter_time(dvp, vp, cnp, NULL, NULL); } /* diff --git a/sys/nfsclient/nfs_vnops.c b/sys/nfsclient/nfs_vnops.c index 241af51410a8..191ed400ac33 100644 --- a/sys/nfsclient/nfs_vnops.c +++ b/sys/nfsclient/nfs_vnops.c @@ -912,7 +912,7 @@ nfs_lookup(struct vop_lookup_args *ap) struct vnode *dvp = ap->a_dvp; struct vnode **vpp = ap->a_vpp; struct mount *mp = dvp->v_mount; - struct vattr vattr; + struct vattr dvattr, vattr; struct timespec nctime; int flags = cnp->cn_flags; struct vnode *newvp; @@ -1129,7 +1129,7 @@ nfs_lookup(struct vop_lookup_args *ap) } if (v3) { nfsm_postop_attr_va(newvp, attrflag, &vattr); - nfsm_postop_attr(dvp, dattrflag); + nfsm_postop_attr_va(dvp, dattrflag, &dvattr); } else { nfsm_loadattr(newvp, &vattr); attrflag = 1; @@ -1137,9 +1137,10 @@ nfs_lookup(struct vop_lookup_args *ap) if (cnp->cn_nameiop != LOOKUP && (flags & ISLASTCN)) cnp->cn_flags |= SAVENAME; if ((cnp->cn_flags & MAKEENTRY) && - (cnp->cn_nameiop != DELETE || !(flags & ISLASTCN)) && attrflag) { - cache_enter_time(dvp, newvp, cnp, &vattr.va_ctime); - } + (cnp->cn_nameiop != DELETE || !(flags & ISLASTCN)) && + attrflag != 0 && (newvp->v_type != VDIR || dattrflag != 0)) + cache_enter_time(dvp, newvp, cnp, &vattr.va_ctime, + newvp->v_type != VDIR ? NULL : &dvattr.va_ctime); *vpp = newvp; m_freem(mrep); nfsmout: @@ -1181,7 +1182,7 @@ nfs_lookup(struct vop_lookup_args *ap) &vattr.va_mtime, ==)) { mtx_unlock(&np->n_mtx); cache_enter_time(dvp, NULL, cnp, - &vattr.va_mtime); + &vattr.va_mtime, NULL); } else mtx_unlock(&np->n_mtx); } @@ -2463,11 +2464,11 @@ nfs_readdirplusrpc(struct vnode *vp, struct uio *uiop, struct ucred *cred) nfsuint64 cookie; struct nfsmount *nmp = VFSTONFS(vp->v_mount); struct nfsnode *dnp = VTONFS(vp), *np; - struct vattr vattr; + struct vattr vattr, dvattr; nfsfh_t *fhp; u_quad_t fileno; int error = 0, tlen, more_dirs = 1, blksiz = 0, doit, bigenough = 1, i; - int attrflag, fhsize; + int attrflag, dattrflag, fhsize; #ifndef nolint dp = NULL; @@ -2513,7 +2514,7 @@ nfs_readdirplusrpc(struct vnode *vp, struct uio *uiop, struct ucred *cred) *tl++ = txdr_unsigned(nmp->nm_readdirsize); *tl = txdr_unsigned(nmp->nm_rsize); nfsm_request(vp, NFSPROC_READDIRPLUS, uiop->uio_td, cred); - nfsm_postop_attr(vp, attrflag); + nfsm_postop_attr_va(vp, dattrflag, &dvattr); if (error) { m_freem(mrep); goto nfsmout; @@ -2649,8 +2650,11 @@ nfs_readdirplusrpc(struct vnode *vp, struct uio *uiop, struct ucred *cred) md = mdsav2; dp->d_type = IFTODT(VTTOIF(vattr.va_type)); ndp->ni_vp = newvp; - cache_enter_time(ndp->ni_dvp, ndp->ni_vp, cnp, - &vattr.va_ctime); + if (newvp->v_type != VDIR || dattrflag != 0) + cache_enter_time(ndp->ni_dvp, ndp->ni_vp, + cnp, &vattr.va_ctime, + newvp->v_type != VDIR ? NULL : + &dvattr.va_ctime); } } else { /* Just skip over the file handle */ diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h index 1b62de018231..ec1d6734a29c 100644 --- a/sys/sys/vnode.h +++ b/sys/sys/vnode.h @@ -583,9 +583,10 @@ struct vnode; /* cache_* may belong in namei.h. */ #define cache_enter(dvp, vp, cnp) \ - cache_enter_time(dvp, vp, cnp, NULL) + cache_enter_time(dvp, vp, cnp, NULL, NULL) void cache_enter_time(struct vnode *dvp, struct vnode *vp, - struct componentname *cnp, struct timespec *tsp); + struct componentname *cnp, struct timespec *tsp, + struct timespec *dtsp); int cache_lookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct timespec *tsp, int *ticksp); void cache_purge(struct vnode *vp);