svn commit: r203303 - head/sys/fs/nfsclient
Rick Macklem
rmacklem at FreeBSD.org
Sun Jan 31 19:12:25 UTC 2010
Author: rmacklem
Date: Sun Jan 31 19:12:24 2010
New Revision: 203303
URL: http://svn.freebsd.org/changeset/base/203303
Log:
Patch the experimental NFS client so that there is a timeout
for negative name cache entries in a manner analogous to
r202767 for the regular NFS client. Also, make the code in
nfs_lookup() compatible with that of the regular client
and replace the sysctl variable that enabled negative name
caching with the mount point option.
MFC after: 2 weeks
Modified:
head/sys/fs/nfsclient/nfs_clvfsops.c
head/sys/fs/nfsclient/nfs_clvnops.c
head/sys/fs/nfsclient/nfsmount.h
head/sys/fs/nfsclient/nfsnode.h
Modified: head/sys/fs/nfsclient/nfs_clvfsops.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clvfsops.c Sun Jan 31 19:04:52 2010 (r203302)
+++ head/sys/fs/nfsclient/nfs_clvfsops.c Sun Jan 31 19:12:24 2010 (r203303)
@@ -99,7 +99,7 @@ static void nfs_decode_args(struct mount
struct nfs_args *argp, struct ucred *, struct thread *);
static int mountnfs(struct nfs_args *, struct mount *,
struct sockaddr *, char *, u_char *, u_char *, u_char *,
- struct vnode **, struct ucred *, struct thread *);
+ struct vnode **, struct ucred *, struct thread *, int);
static vfs_mount_t nfs_mount;
static vfs_cmount_t nfs_cmount;
static vfs_unmount_t nfs_unmount;
@@ -498,7 +498,7 @@ nfs_mountdiskless(char *path,
nam = sodupsockaddr((struct sockaddr *)sin, M_WAITOK);
if ((error = mountnfs(args, mp, nam, path, NULL, NULL, NULL, vpp,
- td->td_ucred, td)) != 0) {
+ td->td_ucred, td, NFS_DEFAULT_NEGNAMETIMEO)) != 0) {
printf("nfs_mountroot: mount %s on /: %d\n", path, error);
return (error);
}
@@ -669,6 +669,7 @@ static const char *nfs_opts[] = { "from"
"retrans", "acregmin", "acregmax", "acdirmin", "acdirmax", "resvport",
"readahead", "hostname", "timeout", "addr", "fh", "nfsv3", "sec",
"principal", "nfsv4", "gssname", "allgssname", "dirpath",
+ "negnametimeo",
NULL };
/*
@@ -717,6 +718,7 @@ nfs_mount(struct mount *mp)
char hst[MNAMELEN];
u_char nfh[NFSX_FHMAX], krbname[100], dirpath[100], srvkrbname[100];
char *opt, *name, *secname;
+ int negnametimeo = NFS_DEFAULT_NEGNAMETIMEO;
if (vfs_filteropt(mp->mnt_optnew, nfs_opts)) {
error = EINVAL;
@@ -891,6 +893,16 @@ nfs_mount(struct mount *mp)
}
args.flags |= NFSMNT_TIMEO;
}
+ if (vfs_getopt(mp->mnt_optnew, "negnametimeo", (void **)&opt, NULL)
+ == 0) {
+ ret = sscanf(opt, "%d", &negnametimeo);
+ if (ret != 1 || negnametimeo < 0) {
+ vfs_mount_error(mp, "illegal negnametimeo: %s",
+ opt);
+ error = EINVAL;
+ goto out;
+ }
+ }
if (vfs_getopt(mp->mnt_optnew, "sec",
(void **) &secname, NULL) == 0)
nfs_sec_name(secname, &args.flags);
@@ -990,7 +1002,7 @@ nfs_mount(struct mount *mp)
args.fh = nfh;
error = mountnfs(&args, mp, nam, hst, krbname, dirpath, srvkrbname,
- &vp, td->td_ucred, td);
+ &vp, td->td_ucred, td, negnametimeo);
out:
if (!error) {
MNT_ILOCK(mp);
@@ -1033,7 +1045,8 @@ nfs_cmount(struct mntarg *ma, void *data
static int
mountnfs(struct nfs_args *argp, struct mount *mp, struct sockaddr *nam,
char *hst, u_char *krbname, u_char *dirpath, u_char *srvkrbname,
- struct vnode **vpp, struct ucred *cred, struct thread *td)
+ struct vnode **vpp, struct ucred *cred, struct thread *td,
+ int negnametimeo)
{
struct nfsmount *nmp;
struct nfsnode *np;
@@ -1101,6 +1114,7 @@ mountnfs(struct nfs_args *argp, struct m
vfs_getnewfsid(mp);
nmp->nm_mountp = mp;
mtx_init(&nmp->nm_mtx, "NFSmount lock", NULL, MTX_DEF | MTX_DUPOK);
+ nmp->nm_negnametimeo = negnametimeo;
nfs_decode_args(mp, nmp, argp, cred, td);
Modified: head/sys/fs/nfsclient/nfs_clvnops.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clvnops.c Sun Jan 31 19:04:52 2010 (r203302)
+++ head/sys/fs/nfsclient/nfs_clvnops.c Sun Jan 31 19:12:24 2010 (r203303)
@@ -220,10 +220,6 @@ int newnfs_directio_enable = 0;
SYSCTL_INT(_vfs_newnfs, OID_AUTO, directio_enable, CTLFLAG_RW,
&newnfs_directio_enable, 0, "Enable NFS directio");
-static int newnfs_neglookup_enable = 1;
-SYSCTL_INT(_vfs_newnfs, OID_AUTO, neglookup_enable, CTLFLAG_RW,
- &newnfs_neglookup_enable, 0, "Enable NFS negative lookup caching");
-
/*
* This sysctl allows other processes to mmap a file that has been opened
* O_DIRECT by a process. In general, having processes mmap the file while
@@ -702,11 +698,11 @@ nfs_close(struct vop_close_args *ap)
* enabled. (What does this have to do with negative lookup
* caching? Well nothing, except it was reported by the
* same user that needed negative lookup caching and I wanted
- * there to be a way to disable it via sysctl to see if it
+ * there to be a way to disable it to see if it
* is the cause of some caching/coherency issue that might
* crop up.)
*/
- if (newnfs_neglookup_enable == 0)
+ if (VFSTONFS(vp->v_mount)->nm_negnametimeo == 0)
np->n_attrstamp = 0;
if (np->n_flag & NWRITEERR) {
np->n_flag &= ~NWRITEERR;
@@ -996,6 +992,8 @@ nfs_lookup(struct vop_lookup_args *ap)
struct thread *td = cnp->cn_thread;
struct nfsfh *nfhp;
struct nfsvattr dnfsva, nfsva;
+ struct vattr vattr;
+ time_t dmtime;
*vpp = NULLVP;
if ((flags & ISLASTCN) && (mp->mnt_flag & MNT_RDONLY) &&
@@ -1016,37 +1014,68 @@ nfs_lookup(struct vop_lookup_args *ap)
if ((error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td)) != 0)
return (error);
- if ((error = cache_lookup(dvp, vpp, cnp)) &&
- (error != ENOENT || newnfs_neglookup_enable != 0)) {
- struct vattr vattr;
-
- if (error == ENOENT) {
- if (!VOP_GETATTR(dvp, &vattr, cnp->cn_cred) &&
- vattr.va_mtime.tv_sec == np->n_dmtime) {
- NFSINCRGLOBAL(newnfsstats.lookupcache_hits);
- return (ENOENT);
- }
- cache_purge_negative(dvp);
- np->n_dmtime = 0;
- } else {
- newvp = *vpp;
- if (nfscl_nodeleg(newvp, 0) == 0 ||
- (!VOP_GETATTR(newvp, &vattr, cnp->cn_cred) &&
- vattr.va_ctime.tv_sec==VTONFS(newvp)->n_ctime)) {
- NFSINCRGLOBAL(newnfsstats.lookupcache_hits);
- if (cnp->cn_nameiop != LOOKUP &&
- (flags & ISLASTCN))
- cnp->cn_flags |= SAVENAME;
- return (0);
- }
- cache_purge(newvp);
- if (dvp != newvp)
- vput(newvp);
- else
- vrele(newvp);
- *vpp = NULLVP;
+ error = cache_lookup(dvp, vpp, cnp);
+ if (error > 0 && error != ENOENT)
+ return (error);
+ if (error == -1) {
+ /*
+ * We only accept a positive hit in the cache if the
+ * change time of the file matches our cached copy.
+ * Otherwise, we discard the cache entry and fallback
+ * to doing a lookup RPC.
+ */
+ newvp = *vpp;
+ if (nfscl_nodeleg(newvp, 0) == 0 ||
+ (!VOP_GETATTR(newvp, &vattr, cnp->cn_cred)
+ && vattr.va_ctime.tv_sec == VTONFS(newvp)->n_ctime)) {
+ NFSINCRGLOBAL(newnfsstats.lookupcache_hits);
+ if (cnp->cn_nameiop != LOOKUP &&
+ (flags & ISLASTCN))
+ cnp->cn_flags |= SAVENAME;
+ return (0);
}
+ cache_purge(newvp);
+ if (dvp != newvp)
+ vput(newvp);
+ else
+ vrele(newvp);
+ *vpp = NULLVP;
+ } else if (error == ENOENT) {
+ if (dvp->v_iflag & VI_DOOMED)
+ return (ENOENT);
+ /*
+ * We only accept a negative hit in the cache if the
+ * modification time of the parent directory matches
+ * our cached copy. Otherwise, we discard all of the
+ * negative cache entries for this directory. We also
+ * only trust -ve cache entries for less than
+ * nm_negative_namecache_timeout seconds.
+ */
+ 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) {
+ NFSINCRGLOBAL(newnfsstats.lookupcache_hits);
+ return (ENOENT);
+ }
+ cache_purge_negative(dvp);
+ mtx_lock(&np->n_mtx);
+ np->n_dmtime = 0;
+ mtx_unlock(&np->n_mtx);
}
+
+ /*
+ * Cache the modification time of the parent directory in case
+ * the lookup fails and results in adding the first negative
+ * name cache entry for the directory. Since this is reading
+ * a single time_t, don't bother with locking. The
+ * modification time may be a bit stale, but it must be read
+ * before performing the lookup RPC to prevent a race where
+ * another lookup updates the timestamp on the directory after
+ * 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;
error = 0;
newvp = NULLVP;
NFSINCRGLOBAL(newnfsstats.lookupcache_misses);
@@ -1056,29 +1085,60 @@ nfs_lookup(struct vop_lookup_args *ap)
if (dattrflag)
(void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1);
if (error) {
- if (newnfs_neglookup_enable != 0 &&
- error == ENOENT && (cnp->cn_flags & MAKEENTRY) &&
- cnp->cn_nameiop != CREATE) {
- if (np->n_dmtime == 0)
- np->n_dmtime = np->n_vattr.na_mtime.tv_sec;
- cache_enter(dvp, NULL, cnp);
- }
if (newvp != NULLVP) {
vput(newvp);
*vpp = NULLVP;
}
+
+ if (error != ENOENT) {
+ if (NFS_ISV4(dvp))
+ error = nfscl_maperr(td, error, (uid_t)0,
+ (gid_t)0);
+ return (error);
+ }
+
+ /* The requested file was not found. */
if ((cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME) &&
- (flags & ISLASTCN) && error == ENOENT) {
+ (flags & ISLASTCN)) {
+ /*
+ * XXX: UFS does a full VOP_ACCESS(dvp,
+ * VWRITE) here instead of just checking
+ * MNT_RDONLY.
+ */
if (mp->mnt_flag & MNT_RDONLY)
- error = EROFS;
- else
- error = EJUSTRETURN;
- }
- if (cnp->cn_nameiop != LOOKUP && (flags & ISLASTCN))
+ return (EROFS);
cnp->cn_flags |= SAVENAME;
- if (NFS_ISV4(dvp))
- error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
- return (error);
+ return (EJUSTRETURN);
+ }
+
+ if ((cnp->cn_flags & MAKEENTRY) && cnp->cn_nameiop != CREATE) {
+ /*
+ * Maintain n_dmtime as the modification time
+ * of the parent directory when the oldest -ve
+ * name cache entry for this directory was
+ * added. If a -ve cache entry has already
+ * been added with a newer modification time
+ * by a concurrent lookup, then don't bother
+ * adding a cache entry. The modification
+ * time of the directory might have changed
+ * due to the file this lookup failed to find
+ * being created. In that case a subsequent
+ * lookup would incorrectly use the entry
+ * added here instead of doing an extra
+ * lookup.
+ */
+ mtx_lock(&np->n_mtx);
+ if (np->n_dmtime <= dmtime) {
+ if (np->n_dmtime == 0) {
+ np->n_dmtime = dmtime;
+ np->n_dmtime_ticks = ticks;
+ }
+ mtx_unlock(&np->n_mtx);
+ cache_enter(dvp, NULL, cnp);
+ } else
+ mtx_unlock(&np->n_mtx);
+ }
+ return (ENOENT);
}
/*
@@ -1829,7 +1889,7 @@ nfs_link(struct vop_link_args *ap)
* but if negative caching is enabled, then the system
* must care about lookup caching hit rate, so...
*/
- if (newnfs_neglookup_enable != 0 &&
+ if (VFSTONFS(vp->v_mount)->nm_negnametimeo != 0 &&
(cnp->cn_flags & MAKEENTRY))
cache_enter(tdvp, vp, cnp);
if (error && NFS_ISV4(vp))
@@ -1893,7 +1953,7 @@ nfs_symlink(struct vop_symlink_args *ap)
* but if negative caching is enabled, then the system
* must care about lookup caching hit rate, so...
*/
- if (newnfs_neglookup_enable != 0 &&
+ if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 &&
(cnp->cn_flags & MAKEENTRY))
cache_enter(dvp, newvp, cnp);
*ap->a_vpp = newvp;
@@ -1973,7 +2033,7 @@ nfs_mkdir(struct vop_mkdir_args *ap)
* but if negative caching is enabled, then the system
* must care about lookup caching hit rate, so...
*/
- if (newnfs_neglookup_enable != 0 &&
+ if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 &&
(cnp->cn_flags & MAKEENTRY))
cache_enter(dvp, newvp, cnp);
*ap->a_vpp = newvp;
Modified: head/sys/fs/nfsclient/nfsmount.h
==============================================================================
--- head/sys/fs/nfsclient/nfsmount.h Sun Jan 31 19:04:52 2010 (r203302)
+++ head/sys/fs/nfsclient/nfsmount.h Sun Jan 31 19:12:24 2010 (r203303)
@@ -69,6 +69,7 @@ struct nfsmount {
u_int64_t nm_maxfilesize; /* maximum file size */
int nm_tprintf_initial_delay; /* initial delay */
int nm_tprintf_delay; /* interval for messages */
+ int nm_negnametimeo; /* timeout for -ve entries (sec) */
/* Newnfs additions */
struct nfsclclient *nm_clp;
@@ -99,6 +100,10 @@ struct nfsmount {
*/
#define VFSTONFS(mp) ((struct nfsmount *)((mp)->mnt_data))
+#ifndef NFS_DEFAULT_NEGNAMETIMEO
+#define NFS_DEFAULT_NEGNAMETIMEO 60
+#endif
+
#endif /* _KERNEL */
#endif /* _NFSCLIENT_NFSMOUNT_H_ */
Modified: head/sys/fs/nfsclient/nfsnode.h
==============================================================================
--- head/sys/fs/nfsclient/nfsnode.h Sun Jan 31 19:04:52 2010 (r203302)
+++ head/sys/fs/nfsclient/nfsnode.h Sun Jan 31 19:12:24 2010 (r203303)
@@ -108,6 +108,7 @@ struct nfsnode {
struct timespec n_mtime; /* Prev modify time. */
time_t n_ctime; /* Prev create time. */
time_t 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 */
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