1 files changed, 95 insertions, 17 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 294692f..7077521 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -66,6 +66,10 @@ 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 */
 
@@ -78,8 +82,13 @@ struct nfs_direct_req {
 	/* completion state */
 	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;
+
 	ssize_t			count,		/* bytes actually processed */
 				bytes_left,	/* bytes left to be sent */
+				io_start,	/* start of IO */
 				error;		/* any reported error */
 	struct completion	completion;	/* wait for i/o completion */
 
@@ -108,26 +117,56 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
 	return atomic_dec_and_test(&dreq->io_count);
 }
 
+void nfs_direct_set_resched_writes(struct nfs_direct_req *dreq)
+{
+	dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+}
+EXPORT_SYMBOL_GPL(nfs_direct_set_resched_writes);
+
+static void
+nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr)
+{
+	int i;
+	ssize_t count;
+
+	WARN_ON_ONCE(hdr->pgio_mirror_idx >= dreq->mirror_count);
+
+	count = dreq->mirrors[hdr->pgio_mirror_idx].count;
+	if (count + dreq->io_start < hdr->io_start + hdr->good_bytes) {
+		count = hdr->io_start + hdr->good_bytes - dreq->io_start;
+		dreq->mirrors[hdr->pgio_mirror_idx].count = count;
+	}
+
+	/* update the dreq->count by finding the minimum agreed count from all
+	 * mirrors */
+	count = dreq->mirrors[0].count;
+
+	for (i = 1; i < dreq->mirror_count; i++)
+		count = min(count, dreq->mirrors[i].count);
+
+	dreq->count = count;
+}
+
 /*
  * nfs_direct_select_verf - select the right verifier
  * @dreq - direct request possibly spanning multiple servers
  * @ds_clp - nfs_client of data server or NULL if MDS / non-pnfs
- * @ds_idx - index of data server in data server list, only valid if ds_clp set
+ * @commit_idx - commit bucket index for the DS
  *
  * returns the correct verifier to use given the role of the server
  */
 static struct nfs_writeverf *
 nfs_direct_select_verf(struct nfs_direct_req *dreq,
 		       struct nfs_client *ds_clp,
-		       int ds_idx)
+		       int commit_idx)
 {
 	struct nfs_writeverf *verfp = &dreq->verf;
 
 #ifdef CONFIG_NFS_V4_1
 	if (ds_clp) {
 		/* pNFS is in use, use the DS verf */
-		if (ds_idx >= 0 && ds_idx < dreq->ds_cinfo.nbuckets)
-			verfp = &dreq->ds_cinfo.buckets[ds_idx].direct_verf;
+		if (commit_idx >= 0 && commit_idx < dreq->ds_cinfo.nbuckets)
+			verfp = &dreq->ds_cinfo.buckets[commit_idx].direct_verf;
 		else
 			WARN_ON_ONCE(1);
 	}
@@ -148,8 +187,7 @@ static void nfs_direct_set_hdr_verf(struct nfs_direct_req *dreq,
 {
 	struct nfs_writeverf *verfp;
 
-	verfp = nfs_direct_select_verf(dreq, hdr->ds_clp,
-				      hdr->ds_idx);
+	verfp = nfs_direct_select_verf(dreq, hdr->ds_clp, hdr->ds_commit_idx);
 	WARN_ON_ONCE(verfp->committed >= 0);
 	memcpy(verfp, &hdr->verf, sizeof(struct nfs_writeverf));
 	WARN_ON_ONCE(verfp->committed < 0);
@@ -169,8 +207,7 @@ static int nfs_direct_set_or_cmp_hdr_verf(struct nfs_direct_req *dreq,
 {
 	struct nfs_writeverf *verfp;
 
-	verfp = nfs_direct_select_verf(dreq, hdr->ds_clp,
-					 hdr->ds_idx);
+	verfp = nfs_direct_select_verf(dreq, hdr->ds_clp, hdr->ds_commit_idx);
 	if (verfp->committed < 0) {
 		nfs_direct_set_hdr_verf(dreq, hdr);
 		return 0;
@@ -193,7 +230,11 @@ static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
 
 	verfp = nfs_direct_select_verf(dreq, data->ds_clp,
 					 data->ds_commit_index);
-	WARN_ON_ONCE(verfp->committed < 0);
+
+	/* verifier not set so always fail */
+	if (verfp->committed < 0)
+		return 1;
+
 	return memcmp(verfp, &data->verf, sizeof(struct nfs_writeverf));
 }
 
@@ -249,6 +290,18 @@ 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;
@@ -263,6 +316,7 @@ 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;
@@ -369,7 +423,8 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
 	if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes == 0))
 		dreq->error = hdr->error;
 	else
-		dreq->count += hdr->good_bytes;
+		nfs_direct_good_bytes(dreq, hdr);
+
 	spin_unlock(&dreq->lock);
 
 	while (!list_empty(&hdr->pages)) {
@@ -547,6 +602,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
 
 	dreq->inode = inode;
 	dreq->bytes_left = count;
+	dreq->io_start = pos;
 	dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
 	l_ctx = nfs_get_lock_context(dreq->ctx);
 	if (IS_ERR(l_ctx)) {
@@ -579,6 +635,20 @@ out:
 	return result;
 }
 
+static void
+nfs_direct_write_scan_commit_list(struct inode *inode,
+				  struct list_head *list,
+				  struct nfs_commit_info *cinfo)
+{
+	spin_lock(cinfo->lock);
+#ifdef CONFIG_NFS_V4_1
+	if (cinfo->ds != NULL && cinfo->ds->nwritten != 0)
+		NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);
+#endif
+	nfs_scan_commit_list(&cinfo->mds->list, list, cinfo, 0);
+	spin_unlock(cinfo->lock);
+}
+
 static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
 {
 	struct nfs_pageio_descriptor desc;
@@ -586,20 +656,23 @@ 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);
-	pnfs_recover_commit_reqs(dreq->inode, &reqs, &cinfo);
-	spin_lock(cinfo.lock);
-	nfs_scan_commit_list(&cinfo.mds->list, &reqs, &cinfo, 0);
-	spin_unlock(cinfo.lock);
+	nfs_direct_write_scan_commit_list(dreq->inode, &reqs, &cinfo);
 
 	dreq->count = 0;
+	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);
+
 	list_for_each_entry_safe(req, tmp, &reqs, wb_list) {
 		if (!nfs_pageio_add_request(&desc, req)) {
 			nfs_list_remove_request(req);
@@ -646,7 +719,7 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data)
 		nfs_list_remove_request(req);
 		if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) {
 			/* Note the rewrite will go through mds */
-			nfs_mark_request_commit(req, NULL, &cinfo);
+			nfs_mark_request_commit(req, NULL, &cinfo, 0);
 		} else
 			nfs_release_request(req);
 		nfs_unlock_and_release_request(req);
@@ -721,7 +794,7 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
 		dreq->error = hdr->error;
 	}
 	if (dreq->error == 0) {
-		dreq->count += hdr->good_bytes;
+		nfs_direct_good_bytes(dreq, hdr);
 		if (nfs_write_need_commit(hdr)) {
 			if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES)
 				request_commit = true;
@@ -745,7 +818,8 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
 		nfs_list_remove_request(req);
 		if (request_commit) {
 			kref_get(&req->wb_kref);
-			nfs_mark_request_commit(req, hdr->lseg, &cinfo);
+			nfs_mark_request_commit(req, hdr->lseg, &cinfo,
+				hdr->ds_commit_idx);
 		}
 		nfs_unlock_and_release_request(req);
 	}
@@ -826,6 +900,9 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 				result = PTR_ERR(req);
 				break;
 			}
+
+			nfs_direct_setup_mirroring(dreq, &desc, req);
+
 			nfs_lock_request(req);
 			req->wb_index = pos >> PAGE_SHIFT;
 			req->wb_offset = pos & ~PAGE_MASK;
@@ -934,6 +1011,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
 
 	dreq->inode = inode;
 	dreq->bytes_left = count;
+	dreq->io_start = pos;
 	dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
 	l_ctx = nfs_get_lock_context(dreq->ctx);
 	if (IS_ERR(l_ctx)) {