Commit 0b574847 authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
Browse files

NFS: Remove redundant mirror tracking in O_DIRECT 



We no longer need the extra mirror length tracking in the O_DIRECT code,
as we are able to track the maximum contiguous length in dreq->max_count.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 031d73ed

fs/nfs/direct.c

+0 −42
Original line number Diff line number Diff line
@@ -64,13 +64,6 @@ 


static struct kmem_cache *nfs_direct_cachep;



/*

 * This represents a set of asynchronous requests that we're waiting on

 */

struct nfs_direct_mirror {

	ssize_t count;

};



struct nfs_direct_req {

	struct kref		kref;		/* release manager */
@@ -84,9 +77,6 @@ struct nfs_direct_req { 
	atomic_t		io_count;	/* i/os we're waiting for */

	spinlock_t		lock;		/* protect completion state */



	struct nfs_direct_mirror mirrors[NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX];

	int			mirror_count;



	loff_t			io_start;	/* Start offset for I/O */

	ssize_t			count,		/* bytes actually processed */

				max_count,	/* max expected count */
@@ -127,8 +117,6 @@ nfs_direct_handle_truncated(struct nfs_direct_req *dreq, 
			    const struct nfs_pgio_header *hdr,

			    ssize_t dreq_len)

{

	struct nfs_direct_mirror *mirror = &dreq->mirrors[hdr->pgio_mirror_idx];



	if (!(test_bit(NFS_IOHDR_ERROR, &hdr->flags) ||

	      test_bit(NFS_IOHDR_EOF, &hdr->flags)))

		return;
@@ -142,15 +130,12 @@ nfs_direct_handle_truncated(struct nfs_direct_req *dreq, 
		else /* Clear outstanding error if this is EOF */

			dreq->error = 0;

	}

	if (mirror->count > dreq_len)

		mirror->count = dreq_len;

}



static void

nfs_direct_count_bytes(struct nfs_direct_req *dreq,

		       const struct nfs_pgio_header *hdr)

{

	struct nfs_direct_mirror *mirror = &dreq->mirrors[hdr->pgio_mirror_idx];

	loff_t hdr_end = hdr->io_start + hdr->good_bytes;

	ssize_t dreq_len = 0;
@@ -162,8 +147,6 @@ nfs_direct_count_bytes(struct nfs_direct_req *dreq, 
	if (dreq_len > dreq->max_count)

		dreq_len = dreq->max_count;



	if (mirror->count < dreq_len)

		mirror->count = dreq_len;

	if (dreq->count < dreq_len)

		dreq->count = dreq_len;

}
@@ -310,18 +293,6 @@ void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo, 
	cinfo->completion_ops = &nfs_direct_commit_completion_ops;

}



static inline void nfs_direct_setup_mirroring(struct nfs_direct_req *dreq,

					     struct nfs_pageio_descriptor *pgio,

					     struct nfs_page *req)

{

	int mirror_count = 1;



	if (pgio->pg_ops->pg_get_mirror_count)

		mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);



	dreq->mirror_count = mirror_count;

}



static inline struct nfs_direct_req *nfs_direct_req_alloc(void)

{

	struct nfs_direct_req *dreq;
@@ -336,7 +307,6 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void) 
	INIT_LIST_HEAD(&dreq->mds_cinfo.list);

	dreq->verf.committed = NFS_INVALID_STABLE_HOW;	/* not set yet */

	INIT_WORK(&dreq->work, nfs_direct_write_schedule_work);

	dreq->mirror_count = 1;

	spin_lock_init(&dreq->lock);



	return dreq;
@@ -655,7 +625,6 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) 
	LIST_HEAD(reqs);

	struct nfs_commit_info cinfo;

	LIST_HEAD(failed);

	int i;



	nfs_init_cinfo_from_dreq(&cinfo, dreq);

	nfs_direct_write_scan_commit_list(dreq->inode, &reqs, &cinfo);
@@ -666,21 +635,12 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) 
		dreq->max_count += req->wb_bytes;

	dreq->verf.committed = NFS_INVALID_STABLE_HOW;

	nfs_clear_pnfs_ds_commit_verifiers(&dreq->ds_cinfo);

	for (i = 0; i < dreq->mirror_count; i++)

		dreq->mirrors[i].count = 0;

	get_dreq(dreq);



	nfs_pageio_init_write(&desc, dreq->inode, FLUSH_STABLE, false,

			      &nfs_direct_write_completion_ops);

	desc.pg_dreq = dreq;



	req = nfs_list_entry(reqs.next);

	nfs_direct_setup_mirroring(dreq, &desc, req);

	if (desc.pg_error < 0) {

		list_splice_init(&reqs, &failed);

		goto out_failed;

	}



	list_for_each_entry_safe(req, tmp, &reqs, wb_list) {

		/* Bump the transmission count */

		req->wb_nio++;
@@ -698,7 +658,6 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) 
	}

	nfs_pageio_complete(&desc);



out_failed:

	while (!list_empty(&failed)) {

		req = nfs_list_entry(failed.next);

		nfs_list_remove_request(req);
@@ -931,7 +890,6 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, 
				break;

			}



			nfs_direct_setup_mirroring(dreq, &desc, req);

			if (desc.pg_error < 0) {

				nfs_free_request(req);

				result = desc.pg_error;