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Diffstat (limited to 'sys/kern/vfs_cache.c')
-rw-r--r--sys/kern/vfs_cache.c106
1 files changed, 96 insertions, 10 deletions
diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index 6427f65..49eccdd 100644
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
@@ -35,6 +35,7 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
+#include "opt_kdtrace.h"
#include "opt_ktrace.h"
#include <sys/param.h>
@@ -47,6 +48,7 @@ __FBSDID("$FreeBSD$");
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
+#include <sys/sdt.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysproto.h>
@@ -58,6 +60,31 @@ __FBSDID("$FreeBSD$");
#include <vm/uma.h>
+SDT_PROVIDER_DECLARE(vfs);
+SDT_PROBE_DEFINE3(vfs, namecache, enter, done, "struct vnode *", "char *",
+ "struct vnode *");
+SDT_PROBE_DEFINE2(vfs, namecache, enter_negative, done, "struct vnode *",
+ "char *");
+SDT_PROBE_DEFINE1(vfs, namecache, fullpath, entry, "struct vnode *");
+SDT_PROBE_DEFINE3(vfs, namecache, fullpath, hit, "struct vnode *",
+ "struct char *", "struct vnode *");
+SDT_PROBE_DEFINE1(vfs, namecache, fullpath, miss, "struct vnode *");
+SDT_PROBE_DEFINE3(vfs, namecache, fullpath, return, "int", "struct vnode *",
+ "struct char *");
+SDT_PROBE_DEFINE3(vfs, namecache, lookup, hit, "struct vnode *", "char *",
+ "struct vnode *");
+SDT_PROBE_DEFINE2(vfs, namecache, lookup, hit_negative, "struct vnode *",
+ "char *");
+SDT_PROBE_DEFINE2(vfs, namecache, lookup, miss, "struct vnode *",
+ "char *");
+SDT_PROBE_DEFINE1(vfs, namecache, purge, done, "struct vnode *");
+SDT_PROBE_DEFINE1(vfs, namecache, purge_negative, done, "struct vnode *");
+SDT_PROBE_DEFINE1(vfs, namecache, purgevfs, done, "struct mount *");
+SDT_PROBE_DEFINE3(vfs, namecache, zap, done, "struct vnode *", "char *",
+ "struct vnode *");
+SDT_PROBE_DEFINE2(vfs, namecache, zap_negative, done, "struct vnode *",
+ "char *");
+
/*
* This structure describes the elements in the cache of recent
* names looked up by namei.
@@ -71,7 +98,7 @@ struct namecache {
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 */
+ char nc_name[0]; /* segment name + nul */
};
/*
@@ -133,9 +160,10 @@ RW_SYSINIT(vfscache, &cache_lock, "Name Cache");
static uma_zone_t cache_zone_small;
static uma_zone_t cache_zone_large;
-#define CACHE_PATH_CUTOFF 32
-#define CACHE_ZONE_SMALL (sizeof(struct namecache) + CACHE_PATH_CUTOFF)
-#define CACHE_ZONE_LARGE (sizeof(struct namecache) + NAME_MAX)
+#define CACHE_PATH_CUTOFF 35
+#define CACHE_ZONE_SMALL (sizeof(struct namecache) + CACHE_PATH_CUTOFF \
+ + 1)
+#define CACHE_ZONE_LARGE (sizeof(struct namecache) + NAME_MAX + 1)
#define cache_alloc(len) uma_zalloc(((len) <= CACHE_PATH_CUTOFF) ? \
cache_zone_small : cache_zone_large, M_WAITOK)
@@ -291,6 +319,15 @@ cache_zap(ncp)
rw_assert(&cache_lock, RA_WLOCKED);
CTR2(KTR_VFS, "cache_zap(%p) vp %p", ncp, ncp->nc_vp);
+#ifdef KDTRACE_HOOKS
+ if (ncp->nc_vp != NULL) {
+ SDT_PROBE(vfs, namecache, zap, done, ncp->nc_dvp,
+ ncp->nc_name, ncp->nc_vp, 0, 0);
+ } else {
+ SDT_PROBE(vfs, namecache, zap_negative, done, ncp->nc_dvp,
+ ncp->nc_name, 0, 0, 0);
+ }
+#endif
vp = NULL;
LIST_REMOVE(ncp, nc_hash);
if (ncp->nc_flag & NCF_ISDOTDOT) {
@@ -361,12 +398,17 @@ retry_wlocked:
CTR2(KTR_VFS, "cache_lookup(%p, %s) found via .",
dvp, cnp->cn_nameptr);
dothits++;
+ SDT_PROBE(vfs, namecache, lookup, hit, dvp, ".",
+ *vpp, 0, 0);
goto success;
}
if (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.') {
dotdothits++;
- if (dvp->v_cache_dd == NULL)
+ if (dvp->v_cache_dd == NULL) {
+ SDT_PROBE(vfs, namecache, lookup, miss, dvp,
+ "..", NULL, 0, 0);
goto unlock;
+ }
if ((cnp->cn_flags & MAKEENTRY) == 0) {
if (dvp->v_cache_dd->nc_flag & NCF_ISDOTDOT)
cache_zap(dvp->v_cache_dd);
@@ -379,6 +421,8 @@ retry_wlocked:
*vpp = dvp->v_cache_dd->nc_dvp;
CTR3(KTR_VFS, "cache_lookup(%p, %s) found %p via ..",
dvp, cnp->cn_nameptr, *vpp);
+ SDT_PROBE(vfs, namecache, lookup, hit, dvp, "..",
+ *vpp, 0, 0);
goto success;
}
}
@@ -394,6 +438,8 @@ retry_wlocked:
/* We failed to find an entry */
if (ncp == NULL) {
+ SDT_PROBE(vfs, namecache, lookup, miss, dvp, cnp->cn_nameptr,
+ NULL, 0, 0);
if ((cnp->cn_flags & MAKEENTRY) == 0) {
nummisszap++;
} else {
@@ -421,6 +467,8 @@ retry_wlocked:
*vpp = ncp->nc_vp;
CTR4(KTR_VFS, "cache_lookup(%p, %s) found %p via ncp %p",
dvp, cnp->cn_nameptr, *vpp, ncp);
+ SDT_PROBE(vfs, namecache, lookup, hit, dvp, ncp->nc_name,
+ *vpp, 0, 0);
goto success;
}
@@ -449,6 +497,8 @@ retry_wlocked:
nchstats.ncs_neghits++;
if (ncp->nc_flag & NCF_WHITE)
cnp->cn_flags |= ISWHITEOUT;
+ SDT_PROBE(vfs, namecache, lookup, hit_negative, dvp, ncp->nc_name,
+ 0, 0, 0);
CACHE_WUNLOCK();
return (ENOENT);
@@ -579,6 +629,8 @@ cache_enter(dvp, vp, cnp)
}
}
dvp->v_cache_dd = NULL;
+ SDT_PROBE(vfs, namecache, enter, done, dvp, "..", vp,
+ 0, 0);
CACHE_WUNLOCK();
flag = NCF_ISDOTDOT;
}
@@ -597,7 +649,7 @@ cache_enter(dvp, vp, cnp)
ncp->nc_flag = flag;
len = ncp->nc_nlen = cnp->cn_namelen;
hash = fnv_32_buf(cnp->cn_nameptr, len, FNV1_32_INIT);
- bcopy(cnp->cn_nameptr, ncp->nc_name, len);
+ strlcpy(ncp->nc_name, cnp->cn_nameptr, len + 1);
hash = fnv_32_buf(&dvp, sizeof(dvp), hash);
CACHE_WLOCK();
@@ -667,8 +719,12 @@ cache_enter(dvp, vp, cnp)
*/
if (vp) {
TAILQ_INSERT_HEAD(&vp->v_cache_dst, ncp, nc_dst);
+ SDT_PROBE(vfs, namecache, enter, done, dvp, ncp->nc_name, vp,
+ 0, 0);
} else {
TAILQ_INSERT_TAIL(&ncneg, ncp, nc_dst);
+ SDT_PROBE(vfs, namecache, enter_negative, done, dvp,
+ ncp->nc_name, 0, 0, 0);
}
if (numneg * ncnegfactor > numcache) {
ncp = TAILQ_FIRST(&ncneg);
@@ -709,6 +765,7 @@ cache_purge(vp)
{
CTR1(KTR_VFS, "cache_purge(%p)", vp);
+ SDT_PROBE(vfs, namecache, purge, done, vp, 0, 0, 0, 0);
CACHE_WLOCK();
while (!LIST_EMPTY(&vp->v_cache_src))
cache_zap(LIST_FIRST(&vp->v_cache_src));
@@ -733,6 +790,7 @@ cache_purge_negative(vp)
struct namecache *cp, *ncp;
CTR1(KTR_VFS, "cache_purge_negative(%p)", vp);
+ SDT_PROBE(vfs, namecache, purge_negative, done, vp, 0, 0, 0, 0);
CACHE_WLOCK();
LIST_FOREACH_SAFE(cp, &vp->v_cache_src, nc_src, ncp) {
if (cp->nc_vp == NULL)
@@ -752,6 +810,7 @@ cache_purgevfs(mp)
struct namecache *ncp, *nnp;
/* Scan hash tables for applicable entries */
+ SDT_PROBE(vfs, namecache, purgevfs, done, mp, 0, 0, 0, 0);
CACHE_WLOCK();
for (ncpp = &nchashtbl[nchash]; ncpp >= nchashtbl; ncpp--) {
LIST_FOREACH_SAFE(ncp, ncpp, nc_hash, nnp) {
@@ -998,6 +1057,9 @@ vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir,
char *bp;
int error, i, slash_prefixed;
struct namecache *ncp;
+#ifdef KDTRACE_HOOKS
+ struct vnode *startvp = vp;
+#endif
buflen--;
bp = buf + buflen;
@@ -1005,6 +1067,7 @@ vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir,
error = 0;
slash_prefixed = 0;
+ SDT_PROBE(vfs, namecache, fullpath, entry, vp, 0, 0, 0, 0);
CACHE_RLOCK();
numfullpathcalls++;
if (vp->v_type != VDIR) {
@@ -1016,18 +1079,31 @@ vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir,
if (bp == buf) {
numfullpathfail4++;
CACHE_RUNLOCK();
- return (ENOMEM);
+ error = ENOMEM;
+ SDT_PROBE(vfs, namecache, fullpath, return,
+ error, startvp, NULL, 0, 0);
+ return (error);
}
+ SDT_PROBE(vfs, namecache, fullpath, hit, ncp->nc_dvp,
+ ncp->nc_name, vp, 0, 0);
vp = ncp->nc_dvp;
} else {
+ SDT_PROBE(vfs, namecache, fullpath, miss, vp, 0, 0,
+ 0, 0);
error = vn_vptocnp(&vp, &bp, buf, &buflen);
- if (error)
+ if (error) {
+ SDT_PROBE(vfs, namecache, fullpath, return,
+ error, startvp, NULL, 0, 0);
return (error);
+ }
}
if (buflen <= 0) {
numfullpathfail4++;
CACHE_RUNLOCK();
- return (ENOMEM);
+ error = ENOMEM;
+ SDT_PROBE(vfs, namecache, fullpath, return, error,
+ startvp, NULL, 0, 0);
+ return (error);
}
*--bp = '/';
buflen--;
@@ -1062,8 +1138,12 @@ vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir,
error = ENOMEM;
break;
}
+ SDT_PROBE(vfs, namecache, fullpath, hit, ncp->nc_dvp,
+ ncp->nc_name, vp, 0, 0);
vp = ncp->nc_dvp;
} else {
+ SDT_PROBE(vfs, namecache, fullpath, miss, vp, 0, 0,
+ 0, 0);
error = vn_vptocnp(&vp, &bp, buf, &buflen);
if (error)
break;
@@ -1078,12 +1158,17 @@ vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir,
buflen--;
slash_prefixed = 1;
}
- if (error)
+ if (error) {
+ SDT_PROBE(vfs, namecache, fullpath, return, error, startvp,
+ NULL, 0, 0);
return (error);
+ }
if (!slash_prefixed) {
if (bp == buf) {
numfullpathfail4++;
CACHE_RUNLOCK();
+ SDT_PROBE(vfs, namecache, fullpath, return, 0,
+ startvp, bp, 0, 0);
return (ENOMEM);
} else
*--bp = '/';
@@ -1091,6 +1176,7 @@ vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir,
numfullpathfound++;
CACHE_RUNLOCK();
+ SDT_PROBE(vfs, namecache, fullpath, return, 0, startvp, bp, 0, 0);
*retbuf = bp;
return (0);
}
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