Commit 5011af4c authored by Trond Myklebust's avatar Trond Myklebust Committed by J. Bruce Fields
Browse files

nfsd: Fix stable writes 



Strictly speaking, a stable write error needs to reflect the
write + the commit of that write (and only that write). To
ensure that we don't pick up the write errors from other
writebacks, add a rw_semaphore to provide exclusion.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 16f8f894

fs/nfsd/filecache.c

+1 −0
Original line number Diff line number Diff line
@@ -195,6 +195,7 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval, 
				__set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags);

		}

		nf->nf_mark = NULL;

		init_rwsem(&nf->nf_rwsem);

		trace_nfsd_file_alloc(nf);

	}

	return nf;

fs/nfsd/filecache.h

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ struct nfsd_file { 
	atomic_t		nf_ref;

	unsigned char		nf_may;

	struct nfsd_file_mark	*nf_mark;

	struct rw_semaphore	nf_rwsem;

};



int nfsd_file_cache_init(void);

fs/nfsd/vfs.c

+16 −2
Original line number Diff line number Diff line
@@ -982,7 +982,18 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 
		flags |= RWF_SYNC;



	iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);

	if (flags & RWF_SYNC) {

		down_write(&nf->nf_rwsem);

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

		if (host_err < 0)

			nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),

						 nfsd_net_id));

		up_write(&nf->nf_rwsem);

	} else {

		down_read(&nf->nf_rwsem);

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

		up_read(&nf->nf_rwsem);

	}

	if (host_err < 0)

		goto out_nfserr;

	*cnt = host_err;
@@ -1097,8 +1108,10 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	if (err)

		goto out;

	if (EX_ISSYNC(fhp->fh_export)) {

		int err2 = vfs_fsync_range(nf->nf_file, offset, end, 0);

		int err2;



		down_write(&nf->nf_rwsem);

		err2 = vfs_fsync_range(nf->nf_file, offset, end, 0);

		switch (err2) {

		case 0:

			break;
@@ -1110,6 +1123,7 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 
			nfsd_reset_boot_verifier(net_generic(nf->nf_net,

						 nfsd_net_id));

		}

		up_write(&nf->nf_rwsem);

	}



	nfsd_file_put(nf);

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