Commit 19e0663f authored by Trond Myklebust's avatar Trond Myklebust Committed by J. Bruce Fields
Browse files

nfsd: Ensure sampling of the write verifier is atomic with the write 



When doing an unstable write, we need to ensure that we sample the
write verifier before releasing the lock, and allowing a commit to
the same file to proceed.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 524ff1af

fs/nfsd/nfs3proc.c

+1 −1
Original line number Diff line number Diff line
@@ -203,7 +203,7 @@ nfsd3_proc_write(struct svc_rqst *rqstp) 
		RETURN_STATUS(nfserr_io);

	nfserr = nfsd_write(rqstp, &resp->fh, argp->offset,

			    rqstp->rq_vec, nvecs, &cnt,

			    resp->committed);

			    resp->committed, resp->verf);

	resp->count = cnt;

	RETURN_STATUS(nfserr);

}

fs/nfsd/nfs3xdr.c

+2 −6
Original line number Diff line number Diff line
@@ -747,17 +747,13 @@ int 
nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p)

{

	struct nfsd3_writeres *resp = rqstp->rq_resp;

	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);

	__be32 verf[2];



	p = encode_wcc_data(rqstp, p, &resp->fh);

	if (resp->status == 0) {

		*p++ = htonl(resp->count);

		*p++ = htonl(resp->committed);

		/* unique identifier, y2038 overflow can be ignored */

		nfsd_copy_boot_verifier(verf, nn);

		*p++ = verf[0];

		*p++ = verf[1];

		*p++ = resp->verf[0];

		*p++ = resp->verf[1];

	}

	return xdr_ressize_check(rqstp, p);

}

fs/nfsd/nfs4proc.c

+2 −2
Original line number Diff line number Diff line
@@ -1015,7 +1015,6 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
	}



	write->wr_how_written = write->wr_stable_how;

	gen_boot_verifier(&write->wr_verifier, SVC_NET(rqstp));



	nvecs = svc_fill_write_vector(rqstp, write->wr_pagelist,

				      &write->wr_head, write->wr_buflen);
@@ -1023,7 +1022,8 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 


	status = nfsd_vfs_write(rqstp, &cstate->current_fh, nf,

				write->wr_offset, rqstp->rq_vec, nvecs, &cnt,

				write->wr_how_written);

				write->wr_how_written,

				(__be32 *)write->wr_verifier.data);

	nfsd_file_put(nf);



	write->wr_bytes_written = cnt;

fs/nfsd/nfsproc.c

+1 −1
Original line number Diff line number Diff line
@@ -226,7 +226,7 @@ nfsd_proc_write(struct svc_rqst *rqstp) 
		return nfserr_io;

	nfserr = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),

			    argp->offset, rqstp->rq_vec, nvecs,

			    &cnt, NFS_DATA_SYNC);

			    &cnt, NFS_DATA_SYNC, NULL);

	return nfsd_return_attrs(nfserr, resp);

}

fs/nfsd/vfs.c

+9 −3
Original line number Diff line number Diff line
@@ -962,7 +962,8 @@ static int wait_for_concurrent_writes(struct file *file) 
__be32

nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,

				loff_t offset, struct kvec *vec, int vlen,

				unsigned long *cnt, int stable)

				unsigned long *cnt, int stable,

				__be32 *verf)

{

	struct file		*file = nf->nf_file;

	struct svc_export	*exp;
@@ -1004,6 +1005,10 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 
		up_write(&nf->nf_rwsem);

	} else {

		down_read(&nf->nf_rwsem);

		if (verf)

			nfsd_copy_boot_verifier(verf,

					net_generic(SVC_NET(rqstp),

					nfsd_net_id));

		host_err = vfs_iter_write(file, &iter, &pos, flags);

		up_read(&nf->nf_rwsem);

	}
@@ -1074,7 +1079,8 @@ __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 
 */

__be32

nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,

	   struct kvec *vec, int vlen, unsigned long *cnt, int stable)

	   struct kvec *vec, int vlen, unsigned long *cnt, int stable,

	   __be32 *verf)

{

	struct nfsd_file *nf;

	__be32 err;
@@ -1086,7 +1092,7 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, 
		goto out;



	err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,

			vlen, cnt, stable);

			vlen, cnt, stable, verf);

	nfsd_file_put(nf);

out:

	trace_nfsd_write_done(rqstp, fhp, offset, *cnt);

CRA Git | Maintained and supported by SUSTech CRA and CCSE