1 files changed, 132 insertions, 199 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index b768a0b42e82..1707f46b1335 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -59,44 +59,13 @@
 #include "internal.h"
 #include "iostat.h"
 #include "pnfs.h"
+#include "fscache.h"
+#include "nfstrace.h"
 
 #define NFSDBG_FACILITY		NFSDBG_VFS
 
 static struct kmem_cache *nfs_direct_cachep;
 
-struct nfs_direct_req {
-	struct kref		kref;		/* release manager */
-
-	/* I/O parameters */
-	struct nfs_open_context	*ctx;		/* file open context info */
-	struct nfs_lock_context *l_ctx;		/* Lock context info */
-	struct kiocb *		iocb;		/* controlling i/o request */
-	struct inode *		inode;		/* target file of i/o */
-
-	/* completion state */
-	atomic_t		io_count;	/* i/os we're waiting for */
-	spinlock_t		lock;		/* protect completion state */
-
-	loff_t			io_start;	/* Start offset for I/O */
-	ssize_t			count,		/* bytes actually processed */
-				max_count,	/* max expected count */
-				bytes_left,	/* bytes left to be sent */
-				error;		/* any reported error */
-	struct completion	completion;	/* wait for i/o completion */
-
-	/* commit state */
-	struct nfs_mds_commit_info mds_cinfo;	/* Storage for cinfo */
-	struct pnfs_ds_commit_info ds_cinfo;	/* Storage for cinfo */
-	struct work_struct	work;
-	int			flags;
-	/* for write */
-#define NFS_ODIRECT_DO_COMMIT		(1)	/* an unstable reply was received */
-#define NFS_ODIRECT_RESCHED_WRITES	(2)	/* write verification failed */
-	/* for read */
-#define NFS_ODIRECT_SHOULD_DIRTY	(3)	/* dirty user-space page after read */
-	struct nfs_writeverf	verf;		/* unstable write verifier */
-};
-
 static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops;
 static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops;
 static void nfs_direct_write_complete(struct nfs_direct_req *dreq);
@@ -151,129 +120,26 @@ nfs_direct_count_bytes(struct nfs_direct_req *dreq,
 		dreq->count = dreq_len;
 }
 
-/*
- * 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
- * @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 commit_idx)
-{
-	struct nfs_writeverf *verfp = &dreq->verf;
-
-#ifdef CONFIG_NFS_V4_1
-	/*
-	 * pNFS is in use, use the DS verf except commit_through_mds is set
-	 * for layout segment where nbuckets is zero.
-	 */
-	if (ds_clp && dreq->ds_cinfo.nbuckets > 0) {
-		if (commit_idx >= 0 && commit_idx < dreq->ds_cinfo.nbuckets)
-			verfp = &dreq->ds_cinfo.buckets[commit_idx].direct_verf;
-		else
-			WARN_ON_ONCE(1);
-	}
-#endif
-	return verfp;
-}
-
-
-/*
- * nfs_direct_set_hdr_verf - set the write/commit verifier
- * @dreq - direct request possibly spanning multiple servers
- * @hdr - pageio header to validate against previously seen verfs
- *
- * Set the server's (MDS or DS) "seen" verifier
- */
-static void nfs_direct_set_hdr_verf(struct nfs_direct_req *dreq,
-				    struct nfs_pgio_header *hdr)
-{
-	struct nfs_writeverf *verfp;
-
-	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);
-}
-
-static int nfs_direct_cmp_verf(const struct nfs_writeverf *v1,
-		const struct nfs_writeverf *v2)
-{
-	return nfs_write_verifier_cmp(&v1->verifier, &v2->verifier);
-}
-
-/*
- * nfs_direct_cmp_hdr_verf - compare verifier for pgio header
- * @dreq - direct request possibly spanning multiple servers
- * @hdr - pageio header to validate against previously seen verf
- *
- * set the server's "seen" verf if not initialized.
- * returns result of comparison between @hdr->verf and the "seen"
- * verf of the server used by @hdr (DS or MDS)
- */
-static int nfs_direct_set_or_cmp_hdr_verf(struct nfs_direct_req *dreq,
-					  struct nfs_pgio_header *hdr)
-{
-	struct nfs_writeverf *verfp;
-
-	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;
-	}
-	return nfs_direct_cmp_verf(verfp, &hdr->verf);
-}
-
-/*
- * nfs_direct_cmp_commit_data_verf - compare verifier for commit data
- * @dreq - direct request possibly spanning multiple servers
- * @data - commit data to validate against previously seen verf
- *
- * returns result of comparison between @data->verf and the verf of
- * the server used by @data (DS or MDS)
- */
-static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
-					   struct nfs_commit_data *data)
-{
-	struct nfs_writeverf *verfp;
-
-	verfp = nfs_direct_select_verf(dreq, data->ds_clp,
-					 data->ds_commit_index);
-
-	/* verifier not set so always fail */
-	if (verfp->committed < 0 || data->res.verf->committed <= NFS_UNSTABLE)
-		return 1;
-
-	return nfs_direct_cmp_verf(verfp, data->res.verf);
-}
-
 /**
- * nfs_direct_IO - NFS address space operation for direct I/O
+ * nfs_swap_rw - NFS address space operation for swap I/O
  * @iocb: target I/O control block
  * @iter: I/O buffer
  *
- * The presence of this routine in the address space ops vector means
- * the NFS client supports direct I/O. However, for most direct IO, we
- * shunt off direct read and write requests before the VFS gets them,
- * so this method is only ever called for swap.
+ * Perform IO to the swap-file.  This is much like direct IO.
  */
-ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+int nfs_swap_rw(struct kiocb *iocb, struct iov_iter *iter)
 {
-	struct inode *inode = iocb->ki_filp->f_mapping->host;
-
-	/* we only support swap file calling nfs_direct_IO */
-	if (!IS_SWAPFILE(inode))
-		return 0;
+	ssize_t ret;
 
 	VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE);
 
 	if (iov_iter_rw(iter) == READ)
-		return nfs_file_direct_read(iocb, iter);
-	return nfs_file_direct_write(iocb, iter);
+		ret = nfs_file_direct_read(iocb, iter, true);
+	else
+		ret = nfs_file_direct_write(iocb, iter, true);
+	if (ret < 0)
+		return ret;
+	return 0;
 }
 
 static void nfs_direct_release_pages(struct page **pages, unsigned int npages)
@@ -305,7 +171,7 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
 	kref_get(&dreq->kref);
 	init_completion(&dreq->completion);
 	INIT_LIST_HEAD(&dreq->mds_cinfo.list);
-	dreq->verf.committed = NFS_INVALID_STABLE_HOW;	/* not set yet */
+	pnfs_init_ds_commit_info(&dreq->ds_cinfo);
 	INIT_WORK(&dreq->work, nfs_direct_write_schedule_work);
 	spin_lock_init(&dreq->lock);
 
@@ -316,7 +182,7 @@ static void nfs_direct_req_free(struct kref *kref)
 {
 	struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref);
 
-	nfs_free_pnfs_ds_cinfo(&dreq->ds_cinfo);
+	pnfs_release_ds_info(&dreq->ds_cinfo, dreq->inode);
 	if (dreq->l_ctx != NULL)
 		nfs_put_lock_context(dreq->l_ctx);
 	if (dreq->ctx != NULL)
@@ -375,7 +241,7 @@ static void nfs_direct_complete(struct nfs_direct_req *dreq)
 			res = (long) dreq->count;
 			WARN_ON_ONCE(dreq->count < 0);
 		}
-		dreq->iocb->ki_complete(dreq->iocb, res, 0);
+		dreq->iocb->ki_complete(dreq->iocb, res);
 	}
 
 	complete(&dreq->completion);
@@ -466,13 +332,12 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
 		size_t pgbase;
 		unsigned npages, i;
 
-		result = iov_iter_get_pages_alloc(iter, &pagevec, 
+		result = iov_iter_get_pages_alloc2(iter, &pagevec,
 						  rsize, &pgbase);
 		if (result < 0)
 			break;
 	
 		bytes = result;
-		iov_iter_advance(iter, bytes);
 		npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
 		for (i = 0; i < npages; i++) {
 			struct nfs_page *req;
@@ -524,6 +389,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
  * nfs_file_direct_read - file direct read operation for NFS files
  * @iocb: target I/O control block
  * @iter: vector of user buffers into which to read data
+ * @swap: flag indicating this is swap IO, not O_DIRECT IO
  *
  * We use this function for direct reads instead of calling
  * generic_file_aio_read() in order to avoid gfar's check to see if
@@ -539,14 +405,15 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
  * client must read the updated atime from the server back into its
  * cache.
  */
-ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter)
+ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
+			     bool swap)
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
 	struct inode *inode = mapping->host;
 	struct nfs_direct_req *dreq;
 	struct nfs_lock_context *l_ctx;
-	ssize_t result = -EINVAL, requested;
+	ssize_t result, requested;
 	size_t count = iov_iter_count(iter);
 	nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count);
 
@@ -571,21 +438,24 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter)
 	l_ctx = nfs_get_lock_context(dreq->ctx);
 	if (IS_ERR(l_ctx)) {
 		result = PTR_ERR(l_ctx);
+		nfs_direct_req_release(dreq);
 		goto out_release;
 	}
 	dreq->l_ctx = l_ctx;
 	if (!is_sync_kiocb(iocb))
 		dreq->iocb = iocb;
 
-	if (iter_is_iovec(iter))
+	if (user_backed_iter(iter))
 		dreq->flags = NFS_ODIRECT_SHOULD_DIRTY;
 
-	nfs_start_io_direct(inode);
+	if (!swap)
+		nfs_start_io_direct(inode);
 
 	NFS_I(inode)->read_io += count;
 	requested = nfs_direct_read_schedule_iovec(dreq, iter, iocb->ki_pos);
 
-	nfs_end_io_direct(inode);
+	if (!swap)
+		nfs_end_io_direct(inode);
 
 	if (requested > 0) {
 		result = nfs_direct_wait(dreq);
@@ -605,15 +475,30 @@ out:
 }
 
 static void
+nfs_direct_join_group(struct list_head *list, struct inode *inode)
+{
+	struct nfs_page *req, *next;
+
+	list_for_each_entry(req, list, wb_list) {
+		if (req->wb_head != req || req->wb_this_page == req)
+			continue;
+		for (next = req->wb_this_page;
+				next != req->wb_head;
+				next = next->wb_this_page) {
+			nfs_list_remove_request(next);
+			nfs_release_request(next);
+		}
+		nfs_join_page_group(req, inode);
+	}
+}
+
+static void
 nfs_direct_write_scan_commit_list(struct inode *inode,
 				  struct list_head *list,
 				  struct nfs_commit_info *cinfo)
 {
 	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
-#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
+	pnfs_recover_commit_reqs(list, cinfo);
 	nfs_scan_commit_list(&cinfo->mds->list, list, cinfo, 0);
 	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 }
@@ -629,11 +514,12 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
 	nfs_init_cinfo_from_dreq(&cinfo, dreq);
 	nfs_direct_write_scan_commit_list(dreq->inode, &reqs, &cinfo);
 
+	nfs_direct_join_group(&reqs, dreq->inode);
+
 	dreq->count = 0;
 	dreq->max_count = 0;
 	list_for_each_entry(req, &reqs, wb_list)
 		dreq->max_count += req->wb_bytes;
-	dreq->verf.committed = NFS_INVALID_STABLE_HOW;
 	nfs_clear_pnfs_ds_commit_verifiers(&dreq->ds_cinfo);
 	get_dreq(dreq);
 
@@ -670,32 +556,43 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
 
 static void nfs_direct_commit_complete(struct nfs_commit_data *data)
 {
+	const struct nfs_writeverf *verf = data->res.verf;
 	struct nfs_direct_req *dreq = data->dreq;
 	struct nfs_commit_info cinfo;
 	struct nfs_page *req;
 	int status = data->task.tk_status;
 
+	trace_nfs_direct_commit_complete(dreq);
+
+	if (status < 0) {
+		/* Errors in commit are fatal */
+		dreq->error = status;
+		dreq->max_count = 0;
+		dreq->count = 0;
+		dreq->flags = NFS_ODIRECT_DONE;
+	} else {
+		status = dreq->error;
+	}
+
 	nfs_init_cinfo_from_dreq(&cinfo, dreq);
-	if (status < 0 || nfs_direct_cmp_commit_data_verf(dreq, data))
-		dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
 
 	while (!list_empty(&data->pages)) {
 		req = nfs_list_entry(data->pages.next);
 		nfs_list_remove_request(req);
-		if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) {
+		if (status >= 0 && !nfs_write_match_verf(verf, req)) {
+			dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
 			/*
 			 * Despite the reboot, the write was successful,
 			 * so reset wb_nio.
 			 */
 			req->wb_nio = 0;
-			/* Note the rewrite will go through mds */
 			nfs_mark_request_commit(req, NULL, &cinfo, 0);
-		} else
+		} else /* Error or match */
 			nfs_release_request(req);
 		nfs_unlock_and_release_request(req);
 	}
 
-	if (atomic_dec_and_test(&cinfo.mds->rpcs_out))
+	if (nfs_commit_end(cinfo.mds))
 		nfs_direct_write_complete(dreq);
 }
 
@@ -704,8 +601,11 @@ static void nfs_direct_resched_write(struct nfs_commit_info *cinfo,
 {
 	struct nfs_direct_req *dreq = cinfo->dreq;
 
+	trace_nfs_direct_resched_write(dreq);
+
 	spin_lock(&dreq->lock);
-	dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+	if (dreq->flags != NFS_ODIRECT_DONE)
+		dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
 	spin_unlock(&dreq->lock);
 	nfs_mark_request_commit(req, NULL, cinfo, 0);
 }
@@ -728,6 +628,23 @@ static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
 		nfs_direct_write_reschedule(dreq);
 }
 
+static void nfs_direct_write_clear_reqs(struct nfs_direct_req *dreq)
+{
+	struct nfs_commit_info cinfo;
+	struct nfs_page *req;
+	LIST_HEAD(reqs);
+
+	nfs_init_cinfo_from_dreq(&cinfo, dreq);
+	nfs_direct_write_scan_commit_list(dreq->inode, &reqs, &cinfo);
+
+	while (!list_empty(&reqs)) {
+		req = nfs_list_entry(reqs.next);
+		nfs_list_remove_request(req);
+		nfs_release_request(req);
+		nfs_unlock_and_release_request(req);
+	}
+}
+
 static void nfs_direct_write_schedule_work(struct work_struct *work)
 {
 	struct nfs_direct_req *dreq = container_of(work, struct nfs_direct_req, work);
@@ -742,6 +659,7 @@ static void nfs_direct_write_schedule_work(struct work_struct *work)
 			nfs_direct_write_reschedule(dreq);
 			break;
 		default:
+			nfs_direct_write_clear_reqs(dreq);
 			nfs_zap_mapping(dreq->inode, dreq->inode->i_mapping);
 			nfs_direct_complete(dreq);
 	}
@@ -749,6 +667,7 @@ static void nfs_direct_write_schedule_work(struct work_struct *work)
 
 static void nfs_direct_write_complete(struct nfs_direct_req *dreq)
 {
+	trace_nfs_direct_write_complete(dreq);
 	queue_work(nfsiod_workqueue, &dreq->work); /* Calls nfs_direct_write_schedule_work */
 }
 
@@ -756,8 +675,10 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
 {
 	struct nfs_direct_req *dreq = hdr->dreq;
 	struct nfs_commit_info cinfo;
-	bool request_commit = false;
 	struct nfs_page *req = nfs_list_entry(hdr->pages.next);
+	int flags = NFS_ODIRECT_DONE;
+
+	trace_nfs_direct_write_completion(dreq);
 
 	nfs_init_cinfo_from_dreq(&cinfo, dreq);
 
@@ -768,21 +689,10 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
 	}
 
 	nfs_direct_count_bytes(dreq, hdr);
-	if (hdr->good_bytes != 0) {
-		if (nfs_write_need_commit(hdr)) {
-			if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES)
-				request_commit = true;
-			else if (dreq->flags == 0) {
-				nfs_direct_set_hdr_verf(dreq, hdr);
-				request_commit = true;
-				dreq->flags = NFS_ODIRECT_DO_COMMIT;
-			} else if (dreq->flags == NFS_ODIRECT_DO_COMMIT) {
-				request_commit = true;
-				if (nfs_direct_set_or_cmp_hdr_verf(dreq, hdr))
-					dreq->flags =
-						NFS_ODIRECT_RESCHED_WRITES;
-			}
-		}
+	if (test_bit(NFS_IOHDR_UNSTABLE_WRITES, &hdr->flags)) {
+		if (!dreq->flags)
+			dreq->flags = NFS_ODIRECT_DO_COMMIT;
+		flags = dreq->flags;
 	}
 	spin_unlock(&dreq->lock);
 
@@ -790,10 +700,15 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
 
 		req = nfs_list_entry(hdr->pages.next);
 		nfs_list_remove_request(req);
-		if (request_commit) {
+		if (flags == NFS_ODIRECT_DO_COMMIT) {
 			kref_get(&req->wb_kref);
+			memcpy(&req->wb_verf, &hdr->verf.verifier,
+			       sizeof(req->wb_verf));
 			nfs_mark_request_commit(req, hdr->lseg, &cinfo,
 				hdr->ds_commit_idx);
+		} else if (flags == NFS_ODIRECT_RESCHED_WRITES) {
+			kref_get(&req->wb_kref);
+			nfs_mark_request_commit(req, NULL, &cinfo, 0);
 		}
 		nfs_unlock_and_release_request(req);
 	}
@@ -819,6 +734,8 @@ static void nfs_direct_write_reschedule_io(struct nfs_pgio_header *hdr)
 {
 	struct nfs_direct_req *dreq = hdr->dreq;
 
+	trace_nfs_direct_write_reschedule_io(dreq);
+
 	spin_lock(&dreq->lock);
 	if (dreq->error == 0) {
 		dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
@@ -851,7 +768,7 @@ static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
  */
 static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 					       struct iov_iter *iter,
-					       loff_t pos)
+					       loff_t pos, int ioflags)
 {
 	struct nfs_pageio_descriptor desc;
 	struct inode *inode = dreq->inode;
@@ -859,7 +776,9 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 	size_t requested_bytes = 0;
 	size_t wsize = max_t(size_t, NFS_SERVER(inode)->wsize, PAGE_SIZE);
 
-	nfs_pageio_init_write(&desc, inode, FLUSH_COND_STABLE, false,
+	trace_nfs_direct_write_schedule_iovec(dreq);
+
+	nfs_pageio_init_write(&desc, inode, ioflags, false,
 			      &nfs_direct_write_completion_ops);
 	desc.pg_dreq = dreq;
 	get_dreq(dreq);
@@ -872,13 +791,12 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 		size_t pgbase;
 		unsigned npages, i;
 
-		result = iov_iter_get_pages_alloc(iter, &pagevec, 
+		result = iov_iter_get_pages_alloc2(iter, &pagevec,
 						  wsize, &pgbase);
 		if (result < 0)
 			break;
 
 		bytes = result;
-		iov_iter_advance(iter, bytes);
 		npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
 		for (i = 0; i < npages; i++) {
 			struct nfs_page *req;
@@ -937,6 +855,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
  * nfs_file_direct_write - file direct write operation for NFS files
  * @iocb: target I/O control block
  * @iter: vector of user buffers from which to write data
+ * @swap: flag indicating this is swap IO, not O_DIRECT IO
  *
  * We use this function for direct writes instead of calling
  * generic_file_aio_write() in order to avoid taking the inode
@@ -953,9 +872,10 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
  * Note that O_APPEND is not supported for NFS direct writes, as there
  * is no atomic O_APPEND write facility in the NFS protocol.
  */
-ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
+ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
+			      bool swap)
 {
-	ssize_t result = -EINVAL, requested;
+	ssize_t result, requested;
 	size_t count;
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
@@ -967,7 +887,11 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
 	dfprintk(FILE, "NFS: direct write(%pD2, %zd@%Ld)\n",
 		file, iov_iter_count(iter), (long long) iocb->ki_pos);
 
-	result = generic_write_checks(iocb, iter);
+	if (swap)
+		/* bypass generic checks */
+		result =  iov_iter_count(iter);
+	else
+		result = generic_write_checks(iocb, iter);
 	if (result <= 0)
 		return result;
 	count = result;
@@ -990,22 +914,30 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
 	l_ctx = nfs_get_lock_context(dreq->ctx);
 	if (IS_ERR(l_ctx)) {
 		result = PTR_ERR(l_ctx);
+		nfs_direct_req_release(dreq);
 		goto out_release;
 	}
 	dreq->l_ctx = l_ctx;
 	if (!is_sync_kiocb(iocb))
 		dreq->iocb = iocb;
+	pnfs_init_ds_commit_info_ops(&dreq->ds_cinfo, inode);
 
-	nfs_start_io_direct(inode);
+	if (swap) {
+		requested = nfs_direct_write_schedule_iovec(dreq, iter, pos,
+							    FLUSH_STABLE);
+	} else {
+		nfs_start_io_direct(inode);
 
-	requested = nfs_direct_write_schedule_iovec(dreq, iter, pos);
+		requested = nfs_direct_write_schedule_iovec(dreq, iter, pos,
+							    FLUSH_COND_STABLE);
 
-	if (mapping->nrpages) {
-		invalidate_inode_pages2_range(mapping,
-					      pos >> PAGE_SHIFT, end);
-	}
+		if (mapping->nrpages) {
+			invalidate_inode_pages2_range(mapping,
+						      pos >> PAGE_SHIFT, end);
+		}
 
-	nfs_end_io_direct(inode);
+		nfs_end_io_direct(inode);
+	}
 
 	if (requested > 0) {
 		result = nfs_direct_wait(dreq);
@@ -1019,6 +951,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
 	} else {
 		result = requested;
 	}
+	nfs_fscache_invalidate(inode, FSCACHE_INVAL_DIO_WRITE);
 out_release:
 	nfs_direct_req_release(dreq);
 out: