---

yaml
---
r: 252235
b: refs/heads/master
c: c3d17b6
h: refs/heads/master
i:
  252233: ac9bdca
  252231: b67ec85
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b2e5cd33b598fb496b9366c445bd77c801efabb8
+refs/heads/master: c3d17b63e5eafcaf2678c11de801c189468631c8

trunk/fs/cifs/file.c

@@ -1092,83 +1092,70 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
 static int cifs_writepages(struct address_space *mapping,
 			   struct writeback_control *wbc)
 {
-	unsigned int bytes_to_write;
-	unsigned int bytes_written;
-	struct cifs_sb_info *cifs_sb;
-	int done = 0;
-	pgoff_t end;
-	pgoff_t index;
-	int range_whole = 0;
-	struct kvec *iov;
-	int len;
-	int n_iov = 0;
-	pgoff_t next;
-	int nr_pages;
-	__u64 offset = 0;
-	struct cifsFileInfo *open_file;
-	struct cifsTconInfo *tcon;
-	struct cifsInodeInfo *cifsi = CIFS_I(mapping->host);
+	struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
+	bool done = false, scanned = false, range_whole = false;
+	pgoff_t end, index;
+	struct cifs_writedata *wdata;
 	struct page *page;
-	struct pagevec pvec;
 	int rc = 0;
-	int scanned = 0;
-	int xid;
-
-	cifs_sb = CIFS_SB(mapping->host->i_sb);
 
 	/*
-	 * If wsize is smaller that the page cache size, default to writing
+	 * If wsize is smaller than the page cache size, default to writing
 	 * one page at a time via cifs_writepage
 	 */
 	if (cifs_sb->wsize < PAGE_CACHE_SIZE)
 		return generic_writepages(mapping, wbc);
 
-	iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL);
-	if (iov == NULL)
-		return generic_writepages(mapping, wbc);
-
-	/*
-	 * if there's no open file, then this is likely to fail too,
-	 * but it'll at least handle the return. Maybe it should be
-	 * a BUG() instead?
-	 */
-	open_file = find_writable_file(CIFS_I(mapping->host), false);
-	if (!open_file) {
-		kfree(iov);
-		return generic_writepages(mapping, wbc);
-	}
-
-	tcon = tlink_tcon(open_file->tlink);
-	cifsFileInfo_put(open_file);
-
-	xid = GetXid();
-
-	pagevec_init(&pvec, 0);
 	if (wbc->range_cyclic) {
 		index = mapping->writeback_index; /* Start from prev offset */
 		end = -1;
 	} else {
 		index = wbc->range_start >> PAGE_CACHE_SHIFT;
 		end = wbc->range_end >> PAGE_CACHE_SHIFT;
 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
-			range_whole = 1;
-		scanned = 1;
+			range_whole = true;
+		scanned = true;
 	}
 retry:
-	while (!done && (index <= end) &&
-	       (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
-			PAGECACHE_TAG_DIRTY,
-			min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
-		int first;
-		unsigned int i;
-
-		first = -1;
-		next = 0;
-		n_iov = 0;
-		bytes_to_write = 0;
-
-		for (i = 0; i < nr_pages; i++) {
-			page = pvec.pages[i];
+	while (!done && index <= end) {
+		unsigned int i, nr_pages, found_pages;
+		pgoff_t next = 0, tofind;
+		struct page **pages;
+
+		tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
+				end - index) + 1;
+
+		wdata = cifs_writedata_alloc((unsigned int)tofind);
+		if (!wdata) {
+			rc = -ENOMEM;
+			break;
+		}
+
+		/*
+		 * find_get_pages_tag seems to return a max of 256 on each
+		 * iteration, so we must call it several times in order to
+		 * fill the array or the wsize is effectively limited to
+		 * 256 * PAGE_CACHE_SIZE.
+		 */
+		found_pages = 0;
+		pages = wdata->pages;
+		do {
+			nr_pages = find_get_pages_tag(mapping, &index,
+							PAGECACHE_TAG_DIRTY,
+							tofind, pages);
+			found_pages += nr_pages;
+			tofind -= nr_pages;
+			pages += nr_pages;
+		} while (nr_pages && tofind && index <= end);
+
+		if (found_pages == 0) {
+			kref_put(&wdata->refcount, cifs_writedata_release);
+			break;
+		}
+
+		nr_pages = 0;
+		for (i = 0; i < found_pages; i++) {
+			page = wdata->pages[i];
 			/*
 			 * At this point we hold neither mapping->tree_lock nor
 			 * lock on the page itself: the page may be truncated or
@@ -1177,7 +1164,7 @@ static int cifs_writepages(struct address_space *mapping,
 			 * mapping
 			 */
 
-			if (first < 0)
+			if (nr_pages == 0)
 				lock_page(page);
 			else if (!trylock_page(page))
 				break;
@@ -1188,7 +1175,7 @@ static int cifs_writepages(struct address_space *mapping,
 			}
 
 			if (!wbc->range_cyclic && page->index > end) {
-				done = 1;
+				done = true;
 				unlock_page(page);
 				break;
 			}
@@ -1215,119 +1202,89 @@ static int cifs_writepages(struct address_space *mapping,
 			set_page_writeback(page);
 
 			if (page_offset(page) >= mapping->host->i_size) {
-				done = 1;
+				done = true;
 				unlock_page(page);
 				end_page_writeback(page);
 				break;
 			}
 
-			/*
-			 * BB can we get rid of this?  pages are held by pvec
-			 */
-			page_cache_get(page);
+			wdata->pages[i] = page;
+			next = page->index + 1;
+			++nr_pages;
+		}
 
-			len = min(mapping->host->i_size - page_offset(page),
-				  (loff_t)PAGE_CACHE_SIZE);
+		/* reset index to refind any pages skipped */
+		if (nr_pages == 0)
+			index = wdata->pages[0]->index + 1;
 
-			/* reserve iov[0] for the smb header */
-			n_iov++;
-			iov[n_iov].iov_base = kmap(page);
-			iov[n_iov].iov_len = len;
-			bytes_to_write += len;
+		/* put any pages we aren't going to use */
+		for (i = nr_pages; i < found_pages; i++) {
+			page_cache_release(wdata->pages[i]);
+			wdata->pages[i] = NULL;
+		}
 
-			if (first < 0) {
-				first = i;
-				offset = page_offset(page);
-			}
-			next = page->index + 1;
-			if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
-				break;
+		/* nothing to write? */
+		if (nr_pages == 0) {
+			kref_put(&wdata->refcount, cifs_writedata_release);
+			continue;
 		}
-		if (n_iov) {
-retry_write:
-			open_file = find_writable_file(CIFS_I(mapping->host),
-							false);
-			if (!open_file) {
-				cERROR(1, "No writable handles for inode");
-				rc = -EBADF;
-			} else {
-				rc = CIFSSMBWrite2(xid, tcon, open_file->netfid,
-						   bytes_to_write, offset,
-						   &bytes_written, iov, n_iov,
-						   0);
-				cifsFileInfo_put(open_file);
-			}
 
-			cFYI(1, "Write2 rc=%d, wrote=%u", rc, bytes_written);
+		wdata->sync_mode = wbc->sync_mode;
+		wdata->nr_pages = nr_pages;
+		wdata->offset = page_offset(wdata->pages[0]);
 
-			/*
-			 * For now, treat a short write as if nothing got
-			 * written. A zero length write however indicates
-			 * ENOSPC or EFBIG. We have no way to know which
-			 * though, so call it ENOSPC for now. EFBIG would
-			 * get translated to AS_EIO anyway.
-			 *
-			 * FIXME: make it take into account the data that did
-			 *	  get written
-			 */
-			if (rc == 0) {
-				if (bytes_written == 0)
-					rc = -ENOSPC;
-				else if (bytes_written < bytes_to_write)
-					rc = -EAGAIN;
+		do {
+			if (wdata->cfile != NULL)
+				cifsFileInfo_put(wdata->cfile);
+			wdata->cfile = find_writable_file(CIFS_I(mapping->host),
+							  false);
+			if (!wdata->cfile) {
+				cERROR(1, "No writable handles for inode");
+				rc = -EBADF;
+				break;
 			}
+			rc = cifs_async_writev(wdata);
+		} while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
 
-			/* retry on data-integrity flush */
-			if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN)
-				goto retry_write;
+		for (i = 0; i < nr_pages; ++i)
+			unlock_page(wdata->pages[i]);
 
-			/* fix the stats and EOF */
-			if (bytes_written > 0) {
-				cifs_stats_bytes_written(tcon, bytes_written);
-				cifs_update_eof(cifsi, offset, bytes_written);
-			}
-
-			for (i = 0; i < n_iov; i++) {
-				page = pvec.pages[first + i];
-				/* on retryable write error, redirty page */
+		/* send failure -- clean up the mess */
+		if (rc != 0) {
+			for (i = 0; i < nr_pages; ++i) {
 				if (rc == -EAGAIN)
-					redirty_page_for_writepage(wbc, page);
-				else if (rc != 0)
-					SetPageError(page);
-				kunmap(page);
-				unlock_page(page);
-				end_page_writeback(page);
-				page_cache_release(page);
+					redirty_page_for_writepage(wbc,
+							   wdata->pages[i]);
+				else
+					SetPageError(wdata->pages[i]);
+				end_page_writeback(wdata->pages[i]);
+				page_cache_release(wdata->pages[i]);
 			}
-
 			if (rc != -EAGAIN)
 				mapping_set_error(mapping, rc);
-			else
-				rc = 0;
+		}
+		kref_put(&wdata->refcount, cifs_writedata_release);
 
-			if ((wbc->nr_to_write -= n_iov) <= 0)
-				done = 1;
-			index = next;
-		} else
-			/* Need to re-find the pages we skipped */
-			index = pvec.pages[0]->index + 1;
+		wbc->nr_to_write -= nr_pages;
+		if (wbc->nr_to_write <= 0)
+			done = true;
 
-		pagevec_release(&pvec);
+		index = next;
 	}
+
 	if (!scanned && !done) {
 		/*
 		 * We hit the last page and there is more work to be done: wrap
 		 * back to the start of the file
 		 */
-		scanned = 1;
+		scanned = true;
 		index = 0;
 		goto retry;
 	}
+
 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
 		mapping->writeback_index = index;
 
-	FreeXid(xid);
-	kfree(iov);
 	return rc;
 }