diff options
| -rw-r--r-- | sys/kern/vfs_cache.c | 127 |
1 files changed, 28 insertions, 99 deletions
diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index b30bc57c575c..bf4cf8c1d61e 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -491,20 +491,6 @@ static int vn_fullpath_dir(struct vnode *vp, struct vnode *rdir, char *buf, static MALLOC_DEFINE(M_VFSCACHE, "vfscache", "VFS name cache entries"); -static int cache_yield; -SYSCTL_INT(_vfs_cache, OID_AUTO, yield, CTLFLAG_RD, &cache_yield, 0, - "Number of times cache called yield"); - -static void __noinline -cache_maybe_yield(void) -{ - - if (should_yield()) { - cache_yield++; - kern_yield(PRI_USER); - } -} - static inline void cache_assert_vlp_locked(struct mtx *vlp) { @@ -1212,51 +1198,6 @@ cache_zap_locked_bucket(struct namecache *ncp, struct componentname *cnp, return (cache_zap_unlocked_bucket(ncp, cnp, dvp, dvlp, vlp, hash, blp)); } -static int -cache_zap_locked_bucket_kl(struct namecache *ncp, struct mtx *blp, - struct mtx **vlpp1, struct mtx **vlpp2) -{ - struct mtx *dvlp, *vlp; - - cache_assert_bucket_locked(ncp); - - dvlp = VP2VNODELOCK(ncp->nc_dvp); - vlp = NULL; - if (!(ncp->nc_flag & NCF_NEGATIVE)) - vlp = VP2VNODELOCK(ncp->nc_vp); - cache_sort_vnodes(&dvlp, &vlp); - - if (*vlpp1 == dvlp && *vlpp2 == vlp) { - cache_zap_locked(ncp); - cache_unlock_vnodes(dvlp, vlp); - *vlpp1 = NULL; - *vlpp2 = NULL; - return (0); - } - - if (*vlpp1 != NULL) - mtx_unlock(*vlpp1); - if (*vlpp2 != NULL) - mtx_unlock(*vlpp2); - *vlpp1 = NULL; - *vlpp2 = NULL; - - if (cache_trylock_vnodes(dvlp, vlp) == 0) { - cache_zap_locked(ncp); - cache_unlock_vnodes(dvlp, vlp); - return (0); - } - - mtx_unlock(blp); - *vlpp1 = dvlp; - *vlpp2 = vlp; - if (*vlpp1 != NULL) - mtx_lock(*vlpp1); - mtx_lock(*vlpp2); - mtx_lock(blp); - return (EAGAIN); -} - static __noinline int cache_remove_cnp(struct vnode *dvp, struct componentname *cnp) { @@ -2316,14 +2257,26 @@ retry: } } +/* + * Opportunistic check to see if there is anything to do. + */ +static bool +cache_has_entries(struct vnode *vp) +{ + + if (LIST_EMPTY(&vp->v_cache_src) && TAILQ_EMPTY(&vp->v_cache_dst) && + vp->v_cache_dd == NULL) + return (false); + return (true); +} + void cache_purge(struct vnode *vp) { struct mtx *vlp; SDT_PROBE1(vfs, namecache, purge, done, vp); - if (LIST_EMPTY(&vp->v_cache_src) && TAILQ_EMPTY(&vp->v_cache_dst) && - vp->v_cache_dd == NULL) + if (!cache_has_entries(vp)) return; vlp = VP2VNODELOCK(vp); mtx_lock(vlp); @@ -2418,49 +2371,25 @@ cache_rename(struct vnode *fdvp, struct vnode *fvp, struct vnode *tdvp, void cache_purgevfs(struct mount *mp, bool force) { - TAILQ_HEAD(, namecache) ncps; - struct mtx *vlp1, *vlp2; - struct mtx *blp; - struct nchashhead *bucket; - struct namecache *ncp, *nnp; - u_long i, j, n_nchash; - int error; + struct vnode *vp, *mvp; - /* Scan hash tables for applicable entries */ SDT_PROBE1(vfs, namecache, purgevfs, done, mp); if (!force && mp->mnt_nvnodelistsize <= ncpurgeminvnodes) return; - TAILQ_INIT(&ncps); - n_nchash = nchash + 1; - vlp1 = vlp2 = NULL; - for (i = 0; i < numbucketlocks; i++) { - blp = (struct mtx *)&bucketlocks[i]; - mtx_lock(blp); - for (j = i; j < n_nchash; j += numbucketlocks) { -retry: - bucket = &nchashtbl[j]; - CK_SLIST_FOREACH_SAFE(ncp, bucket, nc_hash, nnp) { - cache_assert_bucket_locked(ncp); - if (ncp->nc_dvp->v_mount != mp) - continue; - error = cache_zap_locked_bucket_kl(ncp, blp, - &vlp1, &vlp2); - if (error != 0) - goto retry; - TAILQ_INSERT_HEAD(&ncps, ncp, nc_dst); - } - } - mtx_unlock(blp); - if (vlp1 == NULL && vlp2 == NULL) - cache_maybe_yield(); - } - if (vlp1 != NULL) - mtx_unlock(vlp1); - if (vlp2 != NULL) - mtx_unlock(vlp2); - TAILQ_FOREACH_SAFE(ncp, &ncps, nc_dst, nnp) { - cache_free(ncp); + /* + * Somewhat wasteful iteration over all vnodes. Would be better to + * support filtering and avoid the interlock to begin with. + */ + MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { + if (!cache_has_entries(vp)) { + VI_UNLOCK(vp); + continue; + } + vholdl(vp); + VI_UNLOCK(vp); + cache_purge(vp); + vdrop(vp); } } |