nfscl: Handle NFSv4.1/4.2 Close RPC NFSERR_DELAY replies better

Without this patch, if a NFSv4.1/4.2 server replies NFSERR_DELAY to
a Close operation, the client loops retrying the Close while holding
a shared lock on the clientID.  This shared lock blocks returns of
delegations, even though the server has issued a CB_RECALL to request
the delegation return.

This patch delays doing a retry of a Close that received a reply of
NFSERR_DELAY until after the shared lock on the clientID is released,
for NFSv4.1/4.2.  To fix this for NFSv4.0 would be very difficult and
since the only known NFSv4 server to reply NFSERR_DELAY to Close only
does NFSv4.1/4.2, this fix is hoped to be sufficient.

This problem was detected during a recent IETF working group NFSv4
testing event.

MFC after:	2 week
This commit is contained in:
Rick Macklem 2021-10-18 15:02:21 -07:00
parent 73dddffc31
commit 52dee2bc03
3 changed files with 30 additions and 7 deletions

View File

@ -604,7 +604,8 @@ void nfscl_dumpstate(struct nfsmount *, int, int, int, int);
void nfscl_dupopen(vnode_t, int);
int nfscl_getclose(vnode_t, struct nfsclclient **);
int nfscl_doclose(vnode_t, struct nfsclclient **, NFSPROC_T *);
void nfsrpc_doclose(struct nfsmount *, struct nfsclopen *, NFSPROC_T *);
int nfsrpc_doclose(struct nfsmount *, struct nfsclopen *, NFSPROC_T *, bool,
bool);
int nfscl_deleg(mount_t, struct nfsclclient *, u_int8_t *, int,
struct ucred *, NFSPROC_T *, struct nfscldeleg **);
void nfscl_lockinit(struct nfsv4lock *);

View File

@ -760,8 +760,9 @@ nfsrpc_close(vnode_t vp, int doclose, NFSPROC_T *p)
/*
* Close the open.
*/
void
nfsrpc_doclose(struct nfsmount *nmp, struct nfsclopen *op, NFSPROC_T *p)
int
nfsrpc_doclose(struct nfsmount *nmp, struct nfsclopen *op, NFSPROC_T *p,
bool loop_on_delayed, bool freeop)
{
struct nfsrv_descript nfsd, *nd = &nfsd;
struct nfscllockowner *lp, *nlp;
@ -840,7 +841,7 @@ nfsrpc_doclose(struct nfsmount *nmp, struct nfsclopen *op, NFSPROC_T *p)
nfscl_lockexcl(&op->nfso_own->nfsow_rwlock, NFSCLSTATEMUTEXPTR);
NFSUNLOCKCLSTATE();
do {
error = nfscl_tryclose(op, tcred, nmp, p, true);
error = nfscl_tryclose(op, tcred, nmp, p, loop_on_delayed);
if (error == NFSERR_GRACE)
(void) nfs_catnap(PZERO, error, "nfs_close");
} while (error == NFSERR_GRACE);
@ -849,9 +850,11 @@ nfsrpc_doclose(struct nfsmount *nmp, struct nfsclopen *op, NFSPROC_T *p)
LIST_FOREACH_SAFE(lp, &op->nfso_lock, nfsl_list, nlp)
nfscl_freelockowner(lp, 0);
nfscl_freeopen(op, 0, true);
if (freeop && error != NFSERR_DELAY)
nfscl_freeopen(op, 0, true);
NFSUNLOCKCLSTATE();
NFSFREECRED(tcred);
return (error);
}
/*

View File

@ -3327,8 +3327,10 @@ int
nfscl_doclose(vnode_t vp, struct nfsclclient **clpp, NFSPROC_T *p)
{
struct nfsclclient *clp;
struct nfsmount *nmp;
struct nfsclowner *owp, *nowp;
struct nfsclopen *op;
struct nfsclopen *op, *nop;
struct nfsclopenhead delayed;
struct nfscldeleg *dp;
struct nfsfh *nfhp;
struct nfsclrecalllayout *recallp;
@ -3339,6 +3341,7 @@ nfscl_doclose(vnode_t vp, struct nfsclclient **clpp, NFSPROC_T *p)
return (error);
*clpp = clp;
nmp = VFSTONFS(vp->v_mount);
nfhp = VTONFS(vp)->n_fhp;
recallp = malloc(sizeof(*recallp), M_NFSLAYRECALL, M_WAITOK);
NFSLOCKCLSTATE();
@ -3363,6 +3366,7 @@ nfscl_doclose(vnode_t vp, struct nfsclclient **clpp, NFSPROC_T *p)
nfscl_retoncloselayout(vp, clp, nfhp->nfh_fh, nfhp->nfh_len, &recallp);
/* Now process the opens against the server. */
LIST_INIT(&delayed);
lookformore:
LIST_FOREACH(op, NFSCLOPENHASH(clp, nfhp->nfh_fh, nfhp->nfh_len),
nfso_hash) {
@ -3376,8 +3380,16 @@ nfscl_doclose(vnode_t vp, struct nfsclclient **clpp, NFSPROC_T *p)
op->nfso_opencnt));
#endif
NFSUNLOCKCLSTATE();
nfsrpc_doclose(VFSTONFS(vp->v_mount), op, p);
if (NFSHASNFSV4N(nmp))
error = nfsrpc_doclose(nmp, op, p, false, true);
else
error = nfsrpc_doclose(nmp, op, p, true, true);
NFSLOCKCLSTATE();
if (error == NFSERR_DELAY) {
nfscl_unlinkopen(op);
op->nfso_own = NULL;
LIST_INSERT_HEAD(&delayed, op, nfso_list);
}
goto lookformore;
}
}
@ -3388,6 +3400,13 @@ nfscl_doclose(vnode_t vp, struct nfsclclient **clpp, NFSPROC_T *p)
* used by the function, but calling free() with a NULL pointer is ok.
*/
free(recallp, M_NFSLAYRECALL);
/* Now, loop retrying the delayed closes. */
LIST_FOREACH_SAFE(op, &delayed, nfso_list, nop) {
nfsrpc_doclose(nmp, op, p, true, false);
LIST_REMOVE(op, nfso_list);
nfscl_freeopen(op, 0, false);
}
return (0);
}