nfsd_setattr() can kick off a CB_RECALL (via notify_change() -> break_lease()) if a delegation is present. Before returning NFS4ERR_DELAY, give the client holding that delegation a chance to return it and then retry the nfsd_setattr() again, once. Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=354 Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> --- fs/nfsd/nfs4proc.c | 27 ++++++++++++++++++++++++++- fs/nfsd/nfs4state.c | 1 + fs/nfsd/nfsd.h | 1 + fs/nfsd/trace.h | 19 +++++++++++++++++++ 4 files changed, 47 insertions(+), 1 deletion(-) Hi- Naive approach to the issue of clients attempting to use SETATTR without first returning a delegation. I'm interested in testing and suggestions for improving this mechanism. diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 3895eb52d2b1..b4cda7a7e958 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1136,13 +1136,29 @@ nfsd4_secinfo_no_name_release(union nfsd4_op_u *u) exp_put(u->secinfo_no_name.sin_exp); } +/* + * A better approach would wait for the DELEGRETURN operation, and + * retry just as soon as it was done. Unfortunately for NFSv4.0, + * we have only the FH, and there isn't a good way to look up a + * struct nfs4_delegation given an FH. + * + * The timeout prevents deadlock if all nfsd threads happen to be + * tied up waiting for returning delegations. + */ +static void nfsd4_wait_for_delegreturn(struct svc_rqst *rqstp, + struct svc_fh *fhp) +{ + trace_nfsd_delegreturn_wait(rqstp, fhp); + msleep(NFSD_DELEGRETURN_TIMEOUT); +} + static __be32 nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, union nfsd4_op_u *u) { struct nfsd4_setattr *setattr = &u->setattr; __be32 status = nfs_ok; - int err; + int err, tried; if (setattr->sa_iattr.ia_valid & ATTR_SIZE) { status = nfs4_preprocess_stateid_op(rqstp, cstate, @@ -1173,8 +1189,17 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, &setattr->sa_label); if (status) goto out; + + tried = 0; +retry: status = nfsd_setattr(rqstp, &cstate->current_fh, &setattr->sa_iattr, 0, (time64_t)0); + if (unlikely(status == nfserr_jukebox && !tried)) { + nfsd4_wait_for_delegreturn(rqstp, &cstate->current_fh); + tried++; + goto retry; + } + out: fh_drop_write(&cstate->current_fh); return status; diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index 9a8b09afc173..30838149c7ab 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -341,6 +341,7 @@ void nfsd_lockd_shutdown(void); #define NFSD_LAUNDROMAT_MINTIMEOUT 1 /* seconds */ #define NFSD_COURTESY_CLIENT_TIMEOUT (24 * 60 * 60) /* seconds */ +#define NFSD_DELEGRETURN_TIMEOUT (50) /* milliseconds */ /* * The following attributes are currently not supported by the NFSv4 server: diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h index a60ead3b227a..7cc9c6eb4f4e 100644 --- a/fs/nfsd/trace.h +++ b/fs/nfsd/trace.h @@ -443,6 +443,25 @@ DEFINE_NFSD_COPY_ERR_EVENT(clone_file_range_err); #include "filecache.h" #include "vfs.h" +TRACE_EVENT(nfsd_delegreturn_wait, + TP_PROTO( + const struct svc_rqst *rqstp, + const struct svc_fh *fhp + ), + TP_ARGS(rqstp, fhp), + TP_STRUCT__entry( + __field(u32, xid) + __field(u32, fh_hash) + ), + TP_fast_assign( + __entry->xid = be32_to_cpu(rqstp->rq_xid); + __entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle); + ), + TP_printk("xid=0x%08x fh_hash=0x%08x", + __entry->xid, __entry->fh_hash + ) +); + DECLARE_EVENT_CLASS(nfsd_stateid_class, TP_PROTO(stateid_t *stp), TP_ARGS(stp),
