1 files changed, 62 insertions, 55 deletions

diff --git a/fs/iomap.c b/fs/iomap.c
index 97cb9d486a7d..23ef63fd1669 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1,15 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2010 Red Hat, Inc.
  * Copyright (c) 2016-2018 Christoph Hellwig.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
  */
 #include <linux/module.h>
 #include <linux/compiler.h>
@@ -249,6 +241,26 @@ iomap_read_page_end_io(struct bio_vec *bvec, int error)
 }
 
 static void
+iomap_read_end_io(struct bio *bio)
+{
+	int error = blk_status_to_errno(bio->bi_status);
+	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
+
+	bio_for_each_segment_all(bvec, bio, iter_all)
+		iomap_read_page_end_io(bvec, error);
+	bio_put(bio);
+}
+
+struct iomap_readpage_ctx {
+	struct page		*cur_page;
+	bool			cur_page_in_bio;
+	bool			is_readahead;
+	struct bio		*bio;
+	struct list_head	*pages;
+};
+
+static void
 iomap_read_inline_data(struct inode *inode, struct page *page,
 		struct iomap *iomap)
 {
@@ -268,27 +280,6 @@ iomap_read_inline_data(struct inode *inode, struct page *page,
 	SetPageUptodate(page);
 }
 
-static void
-iomap_read_end_io(struct bio *bio)
-{
-	int error = blk_status_to_errno(bio->bi_status);
-	struct bio_vec *bvec;
-	int i;
-	struct bvec_iter_all iter_all;
-
-	bio_for_each_segment_all(bvec, bio, i, iter_all)
-		iomap_read_page_end_io(bvec, error);
-	bio_put(bio);
-}
-
-struct iomap_readpage_ctx {
-	struct page		*cur_page;
-	bool			cur_page_in_bio;
-	bool			is_readahead;
-	struct bio		*bio;
-	struct list_head	*pages;
-};
-
 static loff_t
 iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 		struct iomap *iomap)
@@ -665,6 +656,7 @@ static int
 iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
 		struct page **pagep, struct iomap *iomap)
 {
+	const struct iomap_page_ops *page_ops = iomap->page_ops;
 	pgoff_t index = pos >> PAGE_SHIFT;
 	struct page *page;
 	int status = 0;
@@ -674,9 +666,17 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
 	if (fatal_signal_pending(current))
 		return -EINTR;
 
+	if (page_ops && page_ops->page_prepare) {
+		status = page_ops->page_prepare(inode, pos, len, iomap);
+		if (status)
+			return status;
+	}
+
 	page = grab_cache_page_write_begin(inode->i_mapping, index, flags);
-	if (!page)
-		return -ENOMEM;
+	if (!page) {
+		status = -ENOMEM;
+		goto out_no_page;
+	}
 
 	if (iomap->type == IOMAP_INLINE)
 		iomap_read_inline_data(inode, page, iomap);
@@ -684,15 +684,21 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
 		status = __block_write_begin_int(page, pos, len, NULL, iomap);
 	else
 		status = __iomap_write_begin(inode, pos, len, page, iomap);
-	if (unlikely(status)) {
-		unlock_page(page);
-		put_page(page);
-		page = NULL;
 
-		iomap_write_failed(inode, pos, len);
-	}
+	if (unlikely(status))
+		goto out_unlock;
 
 	*pagep = page;
+	return 0;
+
+out_unlock:
+	unlock_page(page);
+	put_page(page);
+	iomap_write_failed(inode, pos, len);
+
+out_no_page:
+	if (page_ops && page_ops->page_done)
+		page_ops->page_done(inode, pos, 0, NULL, iomap);
 	return status;
 }
 
@@ -738,13 +744,11 @@ __iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
 	 * uptodate page as a zero-length write, and force the caller to redo
 	 * the whole thing.
 	 */
-	if (unlikely(copied < len && !PageUptodate(page))) {
-		copied = 0;
-	} else {
-		iomap_set_range_uptodate(page, offset_in_page(pos), len);
-		iomap_set_page_dirty(page);
-	}
-	return __generic_write_end(inode, pos, copied, page);
+	if (unlikely(copied < len && !PageUptodate(page)))
+		return 0;
+	iomap_set_range_uptodate(page, offset_in_page(pos), len);
+	iomap_set_page_dirty(page);
+	return copied;
 }
 
 static int
@@ -761,7 +765,6 @@ iomap_write_end_inline(struct inode *inode, struct page *page,
 	kunmap_atomic(addr);
 
 	mark_inode_dirty(inode);
-	__generic_write_end(inode, pos, copied, page);
 	return copied;
 }
 
@@ -769,19 +772,22 @@ static int
 iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
 		unsigned copied, struct page *page, struct iomap *iomap)
 {
+	const struct iomap_page_ops *page_ops = iomap->page_ops;
 	int ret;
 
 	if (iomap->type == IOMAP_INLINE) {
 		ret = iomap_write_end_inline(inode, page, iomap, pos, copied);
 	} else if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
-		ret = generic_write_end(NULL, inode->i_mapping, pos, len,
-				copied, page, NULL);
+		ret = block_write_end(NULL, inode->i_mapping, pos, len, copied,
+				page, NULL);
 	} else {
 		ret = __iomap_write_end(inode, pos, len, copied, page, iomap);
 	}
 
-	if (iomap->page_done)
-		iomap->page_done(inode, pos, copied, page, iomap);
+	__generic_write_end(inode, pos, ret, page);
+	if (page_ops && page_ops->page_done)
+		page_ops->page_done(inode, pos, copied, page, iomap);
+	put_page(page);
 
 	if (ret < len)
 		iomap_write_failed(inode, pos, len);
@@ -1589,12 +1595,13 @@ static void iomap_dio_bio_end_io(struct bio *bio)
 	if (should_dirty) {
 		bio_check_pages_dirty(bio);
 	} else {
-		struct bio_vec *bvec;
-		int i;
-		struct bvec_iter_all iter_all;
+		if (!bio_flagged(bio, BIO_NO_PAGE_REF)) {
+			struct bvec_iter_all iter_all;
+			struct bio_vec *bvec;
 
-		bio_for_each_segment_all(bvec, bio, i, iter_all)
-			put_page(bvec->bv_page);
+			bio_for_each_segment_all(bvec, bio, iter_all)
+				put_page(bvec->bv_page);
+		}
 		bio_put(bio);
 	}
 }