Commit 75acacb6 authored by Chuck Lever's avatar Chuck Lever
Browse files

NFSD: Trace boot verifier resets 



According to commit bbf2f098 ("nfsd: Reset the boot verifier on
all write I/O errors"), the Linux NFS server forces all clients to
resend pending unstable writes if any server-side write or commit
operation encounters an error (say, ENOSPC). This is a rare and
quite exceptional event that could require administrative recovery
action, so it should be made trace-able. Example trace event:

nfsd-938   [002]  7174.945558: nfsd_writeverf_reset: boot_time=        61cc920d xid=0xdcd62036 error=-28 new verifier=0x08aecc6142515904

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 3988a578

fs/nfsd/trace.h

+28 −0
Original line number Diff line number Diff line
@@ -574,6 +574,34 @@ DEFINE_EVENT(nfsd_net_class, nfsd_##name, \ 
DEFINE_NET_EVENT(grace_start);

DEFINE_NET_EVENT(grace_complete);



TRACE_EVENT(nfsd_writeverf_reset,

	TP_PROTO(

		const struct nfsd_net *nn,

		const struct svc_rqst *rqstp,

		int error

	),

	TP_ARGS(nn, rqstp, error),

	TP_STRUCT__entry(

		__field(unsigned long long, boot_time)

		__field(u32, xid)

		__field(int, error)

		__array(unsigned char, verifier, NFS4_VERIFIER_SIZE)

	),

	TP_fast_assign(

		__entry->boot_time = nn->boot_time;

		__entry->xid = be32_to_cpu(rqstp->rq_xid);

		__entry->error = error;



		/* avoid seqlock inside TP_fast_assign */

		memcpy(__entry->verifier, nn->writeverf,

		       NFS4_VERIFIER_SIZE);

	),

	TP_printk("boot_time=%16llx xid=0x%08x error=%d new verifier=0x%s",

		__entry->boot_time, __entry->xid, __entry->error,

		__print_hex_str(__entry->verifier, NFS4_VERIFIER_SIZE)

	)

);



TRACE_EVENT(nfsd_clid_cred_mismatch,

	TP_PROTO(

		const struct nfs4_client *clp,

fs/nfsd/vfs.c

+10 −3
Original line number Diff line number Diff line
@@ -553,14 +553,17 @@ __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp, 
		if (!status)

			status = commit_inode_metadata(file_inode(src));

		if (status < 0) {

			struct nfsd_net *nn = net_generic(nf_dst->nf_net,

							  nfsd_net_id);



			trace_nfsd_clone_file_range_err(rqstp,

					&nfsd4_get_cstate(rqstp)->save_fh,

					src_pos,

					&nfsd4_get_cstate(rqstp)->current_fh,

					dst_pos,

					count, status);

			nfsd_reset_write_verifier(net_generic(nf_dst->nf_net,

						  nfsd_net_id));

			nfsd_reset_write_verifier(nn);

			trace_nfsd_writeverf_reset(nn, rqstp, status);

			ret = nfserrno(status);

		}

	}
@@ -1017,6 +1020,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 
	host_err = vfs_iter_write(file, &iter, &pos, flags);

	if (host_err < 0) {

		nfsd_reset_write_verifier(nn);

		trace_nfsd_writeverf_reset(nn, rqstp, host_err);

		goto out_nfserr;

	}

	*cnt = host_err;
@@ -1028,8 +1032,10 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 


	if (stable && use_wgather) {

		host_err = wait_for_concurrent_writes(file);

		if (host_err < 0)

		if (host_err < 0) {

			nfsd_reset_write_verifier(nn);

			trace_nfsd_writeverf_reset(nn, rqstp, host_err);

		}

	}



out_nfserr:
@@ -1151,6 +1157,7 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 
			break;

		default:

			nfsd_reset_write_verifier(nn);

			trace_nfsd_writeverf_reset(nn, rqstp, err2);

		}

		err = nfserrno(err2);

	} else