diff options
author | phk <phk@FreeBSD.org> | 1999-10-03 12:18:29 +0000 |
---|---|---|
committer | phk <phk@FreeBSD.org> | 1999-10-03 12:18:29 +0000 |
commit | 322edeeaa9db24f692a897cb4796b2fb096d1a2c (patch) | |
tree | ec3f444d06a5625603881122124496a55eaa80cb /sys/kern/vfs_cache.c | |
parent | 0a9033ff881571171d2114a65ff650b7d69e1392 (diff) | |
download | FreeBSD-src-322edeeaa9db24f692a897cb4796b2fb096d1a2c.zip FreeBSD-src-322edeeaa9db24f692a897cb4796b2fb096d1a2c.tar.gz |
Before we start to mess with the VFS name-cache clean things up a little bit:
Isolate the namecache in its own file, and give it a dedicated malloc type.
Diffstat (limited to 'sys/kern/vfs_cache.c')
-rw-r--r-- | sys/kern/vfs_cache.c | 155 |
1 files changed, 142 insertions, 13 deletions
diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index 7c7afa3..860db8d 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -45,7 +45,25 @@ #include <sys/vnode.h> #include <sys/namei.h> #include <sys/malloc.h> +#include <sys/sysproto.h> +#include <sys/proc.h> +#include <sys/filedesc.h> +/* + * This structure describes the elements in the cache of recent + * names looked up by namei. + */ + +struct namecache { + LIST_ENTRY(namecache) nc_hash; /* hash chain */ + LIST_ENTRY(namecache) nc_src; /* source vnode list */ + TAILQ_ENTRY(namecache) nc_dst; /* destination vnode list */ + struct vnode *nc_dvp; /* vnode of parent of name */ + struct vnode *nc_vp; /* vnode the name refers to */ + u_char nc_flag; /* flag bits */ + u_char nc_nlen; /* length of name */ + char nc_name[0]; /* segment name */ +}; /* * Name caching works as follows: @@ -67,8 +85,8 @@ /* * Structures associated with name cacheing. */ -#define NCHHASH(dvp, cnp) \ - (&nchashtbl[((dvp)->v_id + (cnp)->cn_hash) & nchash]) +#define NCHHASH(dvp, hash) \ + (&nchashtbl[((dvp)->v_id + (hash)) & nchash]) static LIST_HEAD(nchashhead, namecache) *nchashtbl; /* Hash Table */ static TAILQ_HEAD(, namecache) ncneg; /* Hash Table */ static u_long nchash; /* size of hash table */ @@ -108,6 +126,8 @@ static u_long numneghits; STATNODE(CTLFLAG_RD, numneghits, &numneghits); static void cache_zap __P((struct namecache *ncp)); +MALLOC_DEFINE(M_VFSCACHE, "vfscache", "VFS name cache entries"); + /* * Flags in namecache.nc_flag */ @@ -131,7 +151,7 @@ cache_zap(ncp) numneg--; } numcache--; - free(ncp, M_CACHE); + free(ncp, M_VFSCACHE); } /* @@ -155,7 +175,10 @@ cache_lookup(dvp, vpp, cnp) struct vnode **vpp; struct componentname *cnp; { - register struct namecache *ncp; + struct namecache *ncp; + u_long hash; + u_char *cp; + int len; if (!doingcache) { cnp->cn_flags &= ~MAKEENTRY; @@ -182,7 +205,11 @@ cache_lookup(dvp, vpp, cnp) } } - LIST_FOREACH(ncp, (NCHHASH(dvp, cnp)), nc_hash) { + hash = 0; + len = cnp->cn_namelen; + for (cp = cnp->cn_nameptr; len; len--, cp++) + hash += *cp; + LIST_FOREACH(ncp, (NCHHASH(dvp, hash)), nc_hash) { numchecks++; if (ncp->nc_dvp == dvp && ncp->nc_nlen == cnp->cn_namelen && !bcmp(ncp->nc_name, cnp->cn_nameptr, ncp->nc_nlen)) @@ -246,8 +273,11 @@ cache_enter(dvp, vp, cnp) struct vnode *vp; struct componentname *cnp; { - register struct namecache *ncp; - register struct nchashhead *ncpp; + struct namecache *ncp; + struct nchashhead *ncpp; + u_long hash; + u_char *cp, *dp; + int len; if (!doingcache) return; @@ -269,7 +299,7 @@ cache_enter(dvp, vp, cnp) } ncp = (struct namecache *) - malloc(sizeof *ncp + cnp->cn_namelen, M_CACHE, M_WAITOK); + malloc(sizeof *ncp + cnp->cn_namelen, M_VFSCACHE, M_WAITOK); bzero((char *)ncp, sizeof *ncp); numcache++; if (!vp) { @@ -288,9 +318,12 @@ cache_enter(dvp, vp, cnp) */ ncp->nc_vp = vp; ncp->nc_dvp = dvp; - ncp->nc_nlen = cnp->cn_namelen; - bcopy(cnp->cn_nameptr, ncp->nc_name, ncp->nc_nlen); - ncpp = NCHHASH(dvp, cnp); + len = ncp->nc_nlen = cnp->cn_namelen; + hash = 0; + dp = ncp->nc_name; + for (cp = cnp->cn_nameptr; len; len--, cp++, dp++) + hash += (*dp = *cp); + ncpp = NCHHASH(dvp, hash); LIST_INSERT_HEAD(ncpp, ncp, nc_hash); if (LIST_EMPTY(&dvp->v_cache_src)) vhold(dvp); @@ -300,7 +333,7 @@ cache_enter(dvp, vp, cnp) } else { TAILQ_INSERT_TAIL(&ncneg, ncp, nc_dst); } - if (numneg*ncnegfactor > numcache) { + if (numneg * ncnegfactor > numcache) { ncp = TAILQ_FIRST(&ncneg); cache_zap(ncp); } @@ -314,7 +347,7 @@ nchinit() { TAILQ_INIT(&ncneg); - nchashtbl = hashinit(desiredvnodes*2, M_CACHE, &nchash); + nchashtbl = hashinit(desiredvnodes*2, M_VFSCACHE, &nchash); } /* @@ -456,3 +489,99 @@ vfs_cache_lookup(ap) return (error); return (VOP_CACHEDLOOKUP(ap->a_dvp, ap->a_vpp, ap->a_cnp)); } + + +#ifndef _SYS_SYSPROTO_H_ +struct __getcwd_args { + u_char *buf; + u_int buflen; +}; +#endif + +#define STATNODE(mode, name, var) \ + SYSCTL_INT(_vfs_cache, OID_AUTO, name, mode, var, 0, ""); + +static int disablecwd; +SYSCTL_INT(_debug, OID_AUTO, disablecwd, CTLFLAG_RW, &disablecwd, 0, ""); + +static u_long numcwdcalls; STATNODE(CTLFLAG_RD, numcwdcalls, &numcwdcalls); +static u_long numcwdfail1; STATNODE(CTLFLAG_RD, numcwdfail1, &numcwdfail1); +static u_long numcwdfail2; STATNODE(CTLFLAG_RD, numcwdfail2, &numcwdfail2); +static u_long numcwdfail3; STATNODE(CTLFLAG_RD, numcwdfail3, &numcwdfail3); +static u_long numcwdfail4; STATNODE(CTLFLAG_RD, numcwdfail4, &numcwdfail4); +static u_long numcwdfound; STATNODE(CTLFLAG_RD, numcwdfound, &numcwdfound); +int +__getcwd(p, uap) + struct proc *p; + struct __getcwd_args *uap; +{ + char *bp, *buf; + int error, i, slash_prefixed; + struct filedesc *fdp; + struct namecache *ncp; + struct vnode *vp; + + numcwdcalls++; + if (disablecwd) + return (ENODEV); + if (uap->buflen < 2) + return (EINVAL); + if (uap->buflen > MAXPATHLEN) + uap->buflen = MAXPATHLEN; + buf = bp = malloc(uap->buflen, M_TEMP, M_WAITOK); + bp += uap->buflen - 1; + *bp = '\0'; + fdp = p->p_fd; + slash_prefixed = 0; + for (vp = fdp->fd_cdir; vp != fdp->fd_rdir && vp != rootvnode;) { + if (vp->v_flag & VROOT) { + vp = vp->v_mount->mnt_vnodecovered; + continue; + } + if (vp->v_dd->v_id != vp->v_ddid) { + numcwdfail1++; + free(buf, M_TEMP); + return (ENOTDIR); + } + ncp = TAILQ_FIRST(&vp->v_cache_dst); + if (!ncp) { + numcwdfail2++; + free(buf, M_TEMP); + return (ENOENT); + } + if (ncp->nc_dvp != vp->v_dd) { + numcwdfail3++; + free(buf, M_TEMP); + return (EBADF); + } + for (i = ncp->nc_nlen - 1; i >= 0; i--) { + if (bp == buf) { + numcwdfail4++; + free(buf, M_TEMP); + return (ENOMEM); + } + *--bp = ncp->nc_name[i]; + } + if (bp == buf) { + numcwdfail4++; + free(buf, M_TEMP); + return (ENOMEM); + } + *--bp = '/'; + slash_prefixed = 1; + vp = vp->v_dd; + } + if (!slash_prefixed) { + if (bp == buf) { + numcwdfail4++; + free(buf, M_TEMP); + return (ENOMEM); + } + *--bp = '/'; + } + numcwdfound++; + error = copyout(bp, uap->buf, strlen(bp) + 1); + free(buf, M_TEMP); + return (error); +} + |