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Store the full timestamp when caching timestamps of files and

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directories for purposes of validating name cache entries.  This
closes races where two updates to a file or directory within the same
second could result in stale entries in the name cache.  While here,
remove the 'n_expiry' field as it is no longer used.

Reviewed by:	rmacklem
MFC after:	1 week
This commit is contained in:
John Baldwin 2010-09-07 14:29:45 +00:00
parent e83ea6241a
commit 8e27c18282
5 changed files with 26 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
sys/fs/nfsclient/nfs_clrpcops.c
View File

@ -3293,8 +3293,7 @@ nfsrpc_readdirplus(vnode_t vp, struct uio *uiop, nfsuint64 *cookiep,
ndp->ni_vp = newvp;
NFSCNHASH(cnp, HASHINIT);
if (cnp->cn_namelen <= NCHNAMLEN) {
np->n_ctime =
np->n_vattr.na_ctime.tv_sec;
np->n_ctime = np->n_vattr.na_ctime;
cache_enter(ndp->ni_dvp,ndp->ni_vp,cnp);
}
if (unlocknewvp)

16
sys/fs/nfsclient/nfs_clvnops.c
View File

@ -988,7 +988,7 @@ nfs_lookup(struct vop_lookup_args *ap)
struct nfsfh *nfhp;
struct nfsvattr dnfsva, nfsva;
struct vattr vattr;
time_t dmtime;
struct timespec dmtime;
*vpp = NULLVP;
if ((flags & ISLASTCN) && (mp->mnt_flag & MNT_RDONLY) &&
@ -1038,7 +1038,7 @@ nfs_lookup(struct vop_lookup_args *ap)
}
if (nfscl_nodeleg(newvp, 0) == 0 ||
(VOP_GETATTR(newvp, &vattr, cnp->cn_cred) == 0 &&
vattr.va_ctime.tv_sec == newnp->n_ctime)) {
timespeccmp(&vattr.va_ctime, &newnp->n_ctime, ==))) {
NFSINCRGLOBAL(newnfsstats.lookupcache_hits);
if (cnp->cn_nameiop != LOOKUP &&
(flags & ISLASTCN))
@ -1065,13 +1065,13 @@ nfs_lookup(struct vop_lookup_args *ap)
if ((u_int)(ticks - np->n_dmtime_ticks) <
(nmp->nm_negnametimeo * hz) &&
VOP_GETATTR(dvp, &vattr, cnp->cn_cred) == 0 &&
vattr.va_mtime.tv_sec == np->n_dmtime) {
timespeccmp(&vattr.va_mtime, &np->n_dmtime, ==)) {
NFSINCRGLOBAL(newnfsstats.lookupcache_hits);
return (ENOENT);
}
cache_purge_negative(dvp);
mtx_lock(&np->n_mtx);
np->n_dmtime = 0;
timespecclear(&np->n_dmtime);
mtx_unlock(&np->n_mtx);
}
@ -1086,7 +1086,7 @@ nfs_lookup(struct vop_lookup_args *ap)
* the lookup RPC has been performed on the server but before
* n_dmtime is set at the end of this function.
*/
dmtime = np->n_vattr.na_mtime.tv_sec;
dmtime = np->n_vattr.na_mtime;
error = 0;
newvp = NULLVP;
NFSINCRGLOBAL(newnfsstats.lookupcache_misses);
@ -1139,8 +1139,8 @@ nfs_lookup(struct vop_lookup_args *ap)
* lookup.
*/
mtx_lock(&np->n_mtx);
if (np->n_dmtime <= dmtime) {
if (np->n_dmtime == 0) {
if (timespeccmp(&np->n_dmtime, &dmtime, <=)) {
if (!timespecisset(&np->n_dmtime)) {
np->n_dmtime = dmtime;
np->n_dmtime_ticks = ticks;
}
@ -1241,7 +1241,7 @@ nfs_lookup(struct vop_lookup_args *ap)
cnp->cn_flags |= SAVENAME;
if ((cnp->cn_flags & MAKEENTRY) &&
(cnp->cn_nameiop != DELETE || !(flags & ISLASTCN))) {
np->n_ctime = np->n_vattr.na_vattr.va_ctime.tv_sec;
np->n_ctime = np->n_vattr.na_vattr.va_ctime;
cache_enter(dvp, newvp, cnp);
}
*vpp = newvp;

5
sys/fs/nfsclient/nfsnode.h
View File

@ -96,10 +96,9 @@ struct nfsnode {
time_t n_attrstamp; /* Attr. cache timestamp */
struct nfs_accesscache n_accesscache[NFS_ACCESSCACHESIZE];
struct timespec n_mtime; /* Prev modify time. */
time_t n_ctime; /* Prev create time. */
time_t n_dmtime; /* Prev dir modify time. */
struct timespec n_ctime; /* Prev create time. */
struct timespec n_dmtime; /* Prev dir modify time. */
int n_dmtime_ticks; /* Tick of -ve cache entry */
time_t n_expiry; /* Lease expiry time */
struct nfsfh *n_fhp; /* NFS File Handle */
struct vnode *n_vnode; /* associated vnode */
struct vnode *n_dvp; /* parent vnode */

23
sys/nfsclient/nfs_vnops.c
View File

@ -916,7 +916,7 @@ nfs_lookup(struct vop_lookup_args *ap)
struct vnode **vpp = ap->a_vpp;
struct mount *mp = dvp->v_mount;
struct vattr vattr;
time_t dmtime;
struct timespec dmtime;
int flags = cnp->cn_flags;
struct vnode *newvp;
struct nfsmount *nmp;
@ -970,7 +970,7 @@ nfs_lookup(struct vop_lookup_args *ap)
mtx_unlock(&newnp->n_mtx);
}
if (VOP_GETATTR(newvp, &vattr, cnp->cn_cred) == 0 &&
vattr.va_ctime.tv_sec == newnp->n_ctime) {
timespeccmp(&vattr.va_ctime, &newnp->n_ctime, ==)) {
nfsstats.lookupcache_hits++;
if (cnp->cn_nameiop != LOOKUP &&
(flags & ISLASTCN))
@ -997,13 +997,13 @@ nfs_lookup(struct vop_lookup_args *ap)
if ((u_int)(ticks - np->n_dmtime_ticks) <
(nmp->nm_negnametimeo * hz) &&
VOP_GETATTR(dvp, &vattr, cnp->cn_cred) == 0 &&
vattr.va_mtime.tv_sec == np->n_dmtime) {
timespeccmp(&vattr.va_mtime, &np->n_dmtime, ==)) {
nfsstats.lookupcache_hits++;
return (ENOENT);
}
cache_purge_negative(dvp);
mtx_lock(&np->n_mtx);
np->n_dmtime = 0;
timespecclear(&np->n_dmtime);
mtx_unlock(&np->n_mtx);
}
@ -1018,7 +1018,7 @@ nfs_lookup(struct vop_lookup_args *ap)
* the lookup RPC has been performed on the server but before
* n_dmtime is set at the end of this function.
*/
dmtime = np->n_vattr.va_mtime.tv_sec;
dmtime = np->n_vattr.va_mtime;
error = 0;
newvp = NULLVP;
nfsstats.lookupcache_misses++;
@ -1137,7 +1137,7 @@ nfs_lookup(struct vop_lookup_args *ap)
cnp->cn_flags |= SAVENAME;
if ((cnp->cn_flags & MAKEENTRY) &&
(cnp->cn_nameiop != DELETE || !(flags & ISLASTCN))) {
np->n_ctime = np->n_vattr.va_ctime.tv_sec;
np->n_ctime = np->n_vattr.va_ctime;
cache_enter(dvp, newvp, cnp);
}
*vpp = newvp;
@ -1183,8 +1183,8 @@ nfs_lookup(struct vop_lookup_args *ap)
* lookup.
*/
mtx_lock(&np->n_mtx);
if (np->n_dmtime <= dmtime) {
if (np->n_dmtime == 0) {
if (timespeccmp(&np->n_dmtime, &dmtime, <=)) {
if (!timespecisset(&np->n_dmtime)) {
np->n_dmtime = dmtime;
np->n_dmtime_ticks = ticks;
}
@ -2657,8 +2657,11 @@ nfs_readdirplusrpc(struct vnode *vp, struct uio *uiop, struct ucred *cred)
dp->d_type =
IFTODT(VTTOIF(np->n_vattr.va_type));
ndp->ni_vp = newvp;
/* Update n_ctime, so subsequent lookup doesn't purge entry */
np->n_ctime = np->n_vattr.va_ctime.tv_sec;
/*
* Update n_ctime so subsequent lookup
* doesn't purge entry.
*/
np->n_ctime = np->n_vattr.va_ctime;
cache_enter(ndp->ni_dvp, ndp->ni_vp, cnp);
}
} else {

5
sys/nfsclient/nfsnode.h
View File

@ -102,10 +102,9 @@ struct nfsnode {
time_t n_attrstamp; /* Attr. cache timestamp */
struct nfs_accesscache n_accesscache[NFS_ACCESSCACHESIZE];
struct timespec n_mtime; /* Prev modify time. */
time_t n_ctime; /* Prev create time. */
time_t n_dmtime; /* Prev dir modify time. */
struct timespec n_ctime; /* Prev create time. */
struct timespec n_dmtime; /* Prev dir modify time. */
int n_dmtime_ticks; /* Tick of -ve cache entry */
time_t n_expiry; /* Lease expiry time */
nfsfh_t *n_fhp; /* NFS File Handle */
struct vnode *n_vnode; /* associated vnode */
struct vnode *n_dvp; /* parent vnode */