Merge 208603, 209946, and 209948 to the new NFS client:

Move attribute cache flushes from VOP_OPEN() to VOP_LOOKUP() to provide
more graceful recovery for stale filehandles and eliminate the need for
conditionally clearing the attribute cache in the !NMODIFIED case in
VOP_OPEN().

Reviewed by:	rmacklem
MFC after:	2 weeks
This commit is contained in:
jhb 2010-07-15 19:21:48 +00:00
parent b539225cf9
commit 9e1b696f65

View File

@ -505,9 +505,11 @@ nfs_open(struct vop_open_args *ap)
(void) nfsrpc_close(vp, 0, ap->a_td);
return (error);
}
mtx_lock(&np->n_mtx);
np->n_attrstamp = 0;
if (vp->v_type == VDIR)
np->n_direofoffset = 0;
mtx_unlock(&np->n_mtx);
error = VOP_GETATTR(vp, &vattr, ap->a_cred);
if (error) {
if (NFS_ISV4(vp))
@ -520,14 +522,6 @@ nfs_open(struct vop_open_args *ap)
np->n_change = vattr.va_filerev;
mtx_unlock(&np->n_mtx);
} else {
struct thread *td = curthread;
if (np->n_ac_ts_syscalls != td->td_syscalls ||
np->n_ac_ts_tid != td->td_tid ||
td->td_proc == NULL ||
np->n_ac_ts_pid != td->td_proc->p_pid) {
np->n_attrstamp = 0;
}
mtx_unlock(&np->n_mtx);
error = VOP_GETATTR(vp, &vattr, ap->a_cred);
if (error) {
@ -987,7 +981,7 @@ nfs_lookup(struct vop_lookup_args *ap)
int flags = cnp->cn_flags;
struct vnode *newvp;
struct nfsmount *nmp;
struct nfsnode *np;
struct nfsnode *np, *newnp;
int error = 0, attrflag, dattrflag, ltype;
struct thread *td = cnp->cn_thread;
struct nfsfh *nfhp;
@ -1023,11 +1017,27 @@ nfs_lookup(struct vop_lookup_args *ap)
* change time of the file matches our cached copy.
* Otherwise, we discard the cache entry and fallback
* to doing a lookup RPC.
*
* To better handle stale file handles and attributes,
* clear the attribute cache of this node if it is a
* leaf component, part of an open() call, and not
* locally modified before fetching the attributes.
* This should allow stale file handles to be detected
* here where we can fall back to a LOOKUP RPC to
* recover rather than having nfs_open() detect the
* stale file handle and failing open(2) with ESTALE.
*/
newvp = *vpp;
newnp = VTONFS(newvp);
if ((flags & (ISLASTCN | ISOPEN)) == (ISLASTCN | ISOPEN) &&
!(newnp->n_flag & NMODIFIED)) {
mtx_lock(&newnp->n_mtx);
newnp->n_attrstamp = 0;
mtx_unlock(&newnp->n_mtx);
}
if (nfscl_nodeleg(newvp, 0) == 0 ||
(!VOP_GETATTR(newvp, &vattr, cnp->cn_cred)
&& vattr.va_ctime.tv_sec == VTONFS(newvp)->n_ctime)) {
(VOP_GETATTR(newvp, &vattr, cnp->cn_cred) == 0 &&
vattr.va_ctime.tv_sec == newnp->n_ctime)) {
NFSINCRGLOBAL(newnfsstats.lookupcache_hits);
if (cnp->cn_nameiop != LOOKUP &&
(flags & ISLASTCN))
@ -1213,6 +1223,18 @@ nfs_lookup(struct vop_lookup_args *ap)
if (attrflag)
(void) nfscl_loadattrcache(&newvp, &nfsva, NULL, NULL,
0, 1);
else if ((flags & (ISLASTCN | ISOPEN)) == (ISLASTCN | ISOPEN) &&
!(np->n_flag & NMODIFIED)) {
/*
* Flush the attribute cache when opening a
* leaf node to ensure that fresh attributes
* are fetched in nfs_open() since we did not
* fetch attributes from the LOOKUP reply.
*/
mtx_lock(&np->n_mtx);
np->n_attrstamp = 0;
mtx_unlock(&np->n_mtx);
}
}
if (cnp->cn_nameiop != LOOKUP && (flags & ISLASTCN))
cnp->cn_flags |= SAVENAME;