CIFS: Fix leaking locked VFS cache pages in writeback retry

If we don't find a writable file handle when retrying writepages we break of the loop and do not unlock and put pages neither from wdata2 nor from the original wdata. Fix this by walking through all the remaining pages and cleanup them properly. Cc: <[email protected]> Signed-off-by: Pavel Shilovsky <[email protected]> Signed-off-by: Steve French <[email protected]>
adn770 · Mar 5, 2019 · 165df9a · 165df9a
1 parent 1c163f4
commit 165df9a
Showing 1 changed file with 13 additions and 4 deletions.
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
@@ -2125,12 +2125,13 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
 
 		wdata2->cfile = find_writable_file(CIFS_I(inode), false);
 		if (!wdata2->cfile) {
-			cifs_dbg(VFS, "No writable handles for inode\n");
+			cifs_dbg(VFS, "No writable handle to retry writepages\n");
 			rc = -EBADF;
-			break;
+		} else {
+			wdata2->pid = wdata2->cfile->pid;
+			rc = server->ops->async_writev(wdata2,
+						       cifs_writedata_release);
 		}
-		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]);
@@ -2145,13 +2146,21 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
 			kref_put(&wdata2->refcount, cifs_writedata_release);
 			if (is_retryable_error(rc))
 				continue;
+			i += nr_pages;
 			break;
 		}
 
 		rest_len -= cur_len;
 		i += nr_pages;
 	} while (i < wdata->nr_pages);
 
+	/* cleanup remaining pages from the original wdata */
+	for (; i < wdata->nr_pages; i++) {
+		SetPageError(wdata->pages[i]);
+		end_page_writeback(wdata->pages[i]);
+		put_page(wdata->pages[i]);
+	}
+
 	if (rc != 0 && !is_retryable_error(rc))
 		mapping_set_error(inode->i_mapping, rc);
 	kref_put(&wdata->refcount, cifs_writedata_release);