CIFS: Fix cifs_writev_requeue when wsize changes

If wsize changes on reconnect we need to use new writedata structure
that for retrying.
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

fs/cifs/cifsglob.h

@@ -404,6 +404,8 @@ struct smb_version_operations {
 			const struct cifs_fid *, u32 *);
 	int (*set_acl)(struct cifs_ntsd *, __u32, struct inode *, const char *,
 			int);
+	/* writepages retry size */
+	unsigned int (*wp_retry_size)(struct inode *);
 };
 
 struct smb_version_values {

fs/cifs/cifssmb.c

@@ -1896,28 +1896,80 @@ cifs_writedata_release(struct kref *refcount)
 static void
 cifs_writev_requeue(struct cifs_writedata *wdata)
 {
-	int i, rc;
+	int i, rc = 0;
 	struct inode *inode = wdata->cfile->dentry->d_inode;
 	struct TCP_Server_Info *server;
+	unsigned int rest_len;
 
-	for (i = 0; i < wdata->nr_pages; i++) {
-		lock_page(wdata->pages[i]);
-		clear_page_dirty_for_io(wdata->pages[i]);
-	}
-
+	server = tlink_tcon(wdata->cfile->tlink)->ses->server;
+	i = 0;
+	rest_len = wdata->bytes;
 	do {
-		server = tlink_tcon(wdata->cfile->tlink)->ses->server;
-		rc = server->ops->async_writev(wdata, cifs_writedata_release);
-	} while (rc == -EAGAIN);
+		struct cifs_writedata *wdata2;
+		unsigned int j, nr_pages, wsize, tailsz, cur_len;
+
+		wsize = server->ops->wp_retry_size(inode);
+		if (wsize < rest_len) {
+			nr_pages = wsize / PAGE_CACHE_SIZE;
+			if (!nr_pages) {
+				rc = -ENOTSUPP;
+				break;
+			}
+			cur_len = nr_pages * PAGE_CACHE_SIZE;
+			tailsz = PAGE_CACHE_SIZE;
+		} else {
+			nr_pages = DIV_ROUND_UP(rest_len, PAGE_CACHE_SIZE);
+			cur_len = rest_len;
+			tailsz = rest_len - (nr_pages - 1) * PAGE_CACHE_SIZE;
+		}
 
-	for (i = 0; i < wdata->nr_pages; i++) {
-		unlock_page(wdata->pages[i]);
-		if (rc != 0) {
-			SetPageError(wdata->pages[i]);
-			end_page_writeback(wdata->pages[i]);
-			page_cache_release(wdata->pages[i]);
+		wdata2 = cifs_writedata_alloc(nr_pages, cifs_writev_complete);
+		if (!wdata2) {
+			rc = -ENOMEM;
+			break;
 		}
-	}
+
+		for (j = 0; j < nr_pages; j++) {
+			wdata2->pages[j] = wdata->pages[i + j];
+			lock_page(wdata2->pages[j]);
+			clear_page_dirty_for_io(wdata2->pages[j]);
+		}
+
+		wdata2->sync_mode = wdata->sync_mode;
+		wdata2->nr_pages = nr_pages;
+		wdata2->offset = page_offset(wdata2->pages[0]);
+		wdata2->pagesz = PAGE_CACHE_SIZE;
+		wdata2->tailsz = tailsz;
+		wdata2->bytes = cur_len;
+
+		wdata2->cfile = find_writable_file(CIFS_I(inode), false);
+		if (!wdata2->cfile) {
+			cifs_dbg(VFS, "No writable handles for inode\n");
+			rc = -EBADF;
+			break;
+		}
+		wdata2->pid = wdata2->cfile->pid;
+		rc = server->ops->async_writev(wdata2, cifs_writedata_release);
+
+		for (j = 0; j < nr_pages; j++) {
+			unlock_page(wdata2->pages[j]);
+			if (rc != 0 && rc != -EAGAIN) {
+				SetPageError(wdata2->pages[j]);
+				end_page_writeback(wdata2->pages[j]);
+				page_cache_release(wdata2->pages[j]);
+			}
+		}
+
+		if (rc) {
+			kref_put(&wdata2->refcount, cifs_writedata_release);
+			if (rc == -EAGAIN)
+				continue;
+			break;
+		}
+
+		rest_len -= cur_len;
+		i += nr_pages;
+	} while (i < wdata->nr_pages);
 
 	mapping_set_error(inode->i_mapping, rc);
 	kref_put(&wdata->refcount, cifs_writedata_release);

fs/cifs/smb1ops.c

@@ -1009,6 +1009,12 @@ cifs_is_read_op(__u32 oplock)
 	return oplock == OPLOCK_READ;
 }
 
+static unsigned int
+cifs_wp_retry_size(struct inode *inode)
+{
+	return CIFS_SB(inode->i_sb)->wsize;
+}
+
 struct smb_version_operations smb1_operations = {
 	.send_cancel = send_nt_cancel,
 	.compare_fids = cifs_compare_fids,
@@ -1078,6 +1084,7 @@ struct smb_version_operations smb1_operations = {
 	.query_mf_symlink = cifs_query_mf_symlink,
 	.create_mf_symlink = cifs_create_mf_symlink,
 	.is_read_op = cifs_is_read_op,
+	.wp_retry_size = cifs_wp_retry_size,
 #ifdef CONFIG_CIFS_XATTR
 	.query_all_EAs = CIFSSMBQAllEAs,
 	.set_EA = CIFSSMBSetEA,

fs/cifs/smb2ops.c

@@ -1104,6 +1104,13 @@ smb3_parse_lease_buf(void *buf, unsigned int *epoch)
 	return le32_to_cpu(lc->lcontext.LeaseState);
 }
 
+static unsigned int
+smb2_wp_retry_size(struct inode *inode)
+{
+	return min_t(unsigned int, CIFS_SB(inode->i_sb)->wsize,
+		     SMB2_MAX_BUFFER_SIZE);
+}
+
 struct smb_version_operations smb20_operations = {
 	.compare_fids = smb2_compare_fids,
 	.setup_request = smb2_setup_request,
@@ -1177,6 +1184,7 @@ struct smb_version_operations smb20_operations = {
 	.create_lease_buf = smb2_create_lease_buf,
 	.parse_lease_buf = smb2_parse_lease_buf,
 	.clone_range = smb2_clone_range,
+	.wp_retry_size = smb2_wp_retry_size,
 };
 
 struct smb_version_operations smb21_operations = {
@@ -1252,6 +1260,7 @@ struct smb_version_operations smb21_operations = {
 	.create_lease_buf = smb2_create_lease_buf,
 	.parse_lease_buf = smb2_parse_lease_buf,
 	.clone_range = smb2_clone_range,
+	.wp_retry_size = smb2_wp_retry_size,
 };
 
 struct smb_version_operations smb30_operations = {
@@ -1330,6 +1339,7 @@ struct smb_version_operations smb30_operations = {
 	.parse_lease_buf = smb3_parse_lease_buf,
 	.clone_range = smb2_clone_range,
 	.validate_negotiate = smb3_validate_negotiate,
+	.wp_retry_size = smb2_wp_retry_size,
 };
 
 struct smb_version_values smb20_values = {