1 files changed, 18 insertions, 13 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 741a92c470bb..e6210ead71d0 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -87,6 +87,7 @@ struct nfs_direct_req {
 	int			mirror_count;
 
 	ssize_t			count,		/* bytes actually processed */
+				max_count,	/* max expected count */
 				bytes_left,	/* bytes left to be sent */
 				io_start,	/* start of IO */
 				error;		/* any reported error */
@@ -123,6 +124,8 @@ nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr)
 	int i;
 	ssize_t count;
 
+	WARN_ON_ONCE(dreq->count >= dreq->max_count);
+
 	if (dreq->mirror_count == 1) {
 		dreq->mirrors[hdr->pgio_mirror_idx].count += hdr->good_bytes;
 		dreq->count += hdr->good_bytes;
@@ -241,9 +244,7 @@ static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
 /**
  * nfs_direct_IO - NFS address space operation for direct I/O
  * @iocb: target I/O control block
- * @iov: array of vectors that define I/O buffer
- * @pos: offset in file to begin the operation
- * @nr_segs: size of iovec array
+ * @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
@@ -275,7 +276,7 @@ static void nfs_direct_release_pages(struct page **pages, unsigned int npages)
 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
 			      struct nfs_direct_req *dreq)
 {
-	cinfo->lock = &dreq->inode->i_lock;
+	cinfo->inode = dreq->inode;
 	cinfo->mds = &dreq->mds_cinfo;
 	cinfo->ds = &dreq->ds_cinfo;
 	cinfo->dreq = dreq;
@@ -350,10 +351,12 @@ static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq)
 
 	result = wait_for_completion_killable(&dreq->completion);
 
+	if (!result) {
+		result = dreq->count;
+		WARN_ON_ONCE(dreq->count < 0);
+	}
 	if (!result)
 		result = dreq->error;
-	if (!result)
-		result = dreq->count;
 
 out:
 	return (ssize_t) result;
@@ -383,8 +386,10 @@ static void nfs_direct_complete(struct nfs_direct_req *dreq, bool write)
 
 	if (dreq->iocb) {
 		long res = (long) dreq->error;
-		if (!res)
+		if (dreq->count != 0) {
 			res = (long) dreq->count;
+			WARN_ON_ONCE(dreq->count < 0);
+		}
 		dreq->iocb->ki_complete(dreq->iocb, res, 0);
 	}
 
@@ -591,7 +596,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter)
 		goto out_unlock;
 
 	dreq->inode = inode;
-	dreq->bytes_left = count;
+	dreq->bytes_left = dreq->max_count = count;
 	dreq->io_start = iocb->ki_pos;
 	dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
 	l_ctx = nfs_get_lock_context(dreq->ctx);
@@ -630,13 +635,13 @@ nfs_direct_write_scan_commit_list(struct inode *inode,
 				  struct list_head *list,
 				  struct nfs_commit_info *cinfo)
 {
-	spin_lock(cinfo->lock);
+	spin_lock(&cinfo->inode->i_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);
+	spin_unlock(&cinfo->inode->i_lock);
 }
 
 static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
@@ -671,13 +676,13 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
 		if (!nfs_pageio_add_request(&desc, req)) {
 			nfs_list_remove_request(req);
 			nfs_list_add_request(req, &failed);
-			spin_lock(cinfo.lock);
+			spin_lock(&cinfo.inode->i_lock);
 			dreq->flags = 0;
 			if (desc.pg_error < 0)
 				dreq->error = desc.pg_error;
 			else
 				dreq->error = -EIO;
-			spin_unlock(cinfo.lock);
+			spin_unlock(&cinfo.inode->i_lock);
 		}
 		nfs_release_request(req);
 	}
@@ -1023,7 +1028,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
 		goto out_unlock;
 
 	dreq->inode = inode;
-	dreq->bytes_left = iov_iter_count(iter);
+	dreq->bytes_left = dreq->max_count = iov_iter_count(iter);
 	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);