btrfs: Remove extent_io_ops::writepage_end_io_hook

This callback is ony ever called for data page writeout so there is no
need to actually abstract it via extent_io_ops. Lets just export it,
remove the definition of the callback and call it directly in the
functions that invoke the callback. Also rename the function to
btrfs_writepage_endio_finish_ordered since what it really does is
account finished io in the ordered extent data structures.  No
functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/compression.c

@@ -229,7 +229,6 @@ static noinline void end_compressed_writeback(struct inode *inode,
  */
 static void end_compressed_bio_write(struct bio *bio)
 {
-	struct extent_io_tree *tree;
 	struct compressed_bio *cb = bio->bi_private;
 	struct inode *inode;
 	struct page *page;
@@ -248,14 +247,10 @@ static void end_compressed_bio_write(struct bio *bio)
 	 * call back into the FS and do all the end_io operations
 	 */
 	inode = cb->inode;
-	tree = &BTRFS_I(inode)->io_tree;
 	cb->compressed_pages[0]->mapping = cb->inode->i_mapping;
-	tree->ops->writepage_end_io_hook(cb->compressed_pages[0],
-					 cb->start,
-					 cb->start + cb->len - 1,
-					 NULL,
-					 bio->bi_status ?
-					 BLK_STS_OK : BLK_STS_NOTSUPP);
+	btrfs_writepage_endio_finish_ordered(cb->compressed_pages[0],
+			cb->start, cb->start + cb->len - 1, NULL,
+			bio->bi_status ? BLK_STS_OK : BLK_STS_NOTSUPP);
 	cb->compressed_pages[0]->mapping = NULL;
 
 	end_compressed_writeback(inode, cb);

fs/btrfs/ctree.h

@@ -3193,6 +3193,8 @@ int btrfs_run_delalloc_range(void *private_data, struct page *locked_page,
 		u64 start, u64 end, int *page_started, unsigned long *nr_written,
 		struct writeback_control *wbc);
 int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end);
+void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
+		u64 end, struct extent_state *state, int uptodate);
 extern const struct dentry_operations btrfs_dentry_operations;
 
 /* ioctl.c */

fs/btrfs/extent_io.c

@@ -2412,14 +2412,9 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
 {
 	int uptodate = (err == 0);
-	struct extent_io_tree *tree;
 	int ret = 0;
 
-	tree = &BTRFS_I(page->mapping->host)->io_tree;
-
-	if (tree->ops && tree->ops->writepage_end_io_hook)
-		tree->ops->writepage_end_io_hook(page, start, end, NULL,
-				uptodate);
+	btrfs_writepage_endio_finish_ordered(page, start, end, NULL, uptodate);
 
 	if (!uptodate) {
 		ClearPageUptodate(page);
@@ -3342,9 +3337,8 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
 
 	end = page_end;
 	if (i_size <= start) {
-		if (tree->ops && tree->ops->writepage_end_io_hook)
-			tree->ops->writepage_end_io_hook(page, start,
-							 page_end, NULL, 1);
+		btrfs_writepage_endio_finish_ordered(page, start, page_end,
+						     NULL, 1);
 		goto done;
 	}
 
@@ -3355,9 +3349,8 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
 		u64 offset;
 
 		if (cur >= i_size) {
-			if (tree->ops && tree->ops->writepage_end_io_hook)
-				tree->ops->writepage_end_io_hook(page, cur,
-							 page_end, NULL, 1);
+			btrfs_writepage_endio_finish_ordered(page, cur,
+							     page_end, NULL, 1);
 			break;
 		}
 		em = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, cur,
@@ -3391,11 +3384,10 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
 			 * end_io notification does not happen here for
 			 * compressed extents
 			 */
-			if (!compressed && tree->ops &&
-			    tree->ops->writepage_end_io_hook)
-				tree->ops->writepage_end_io_hook(page, cur,
-							 cur + iosize - 1,
-							 NULL, 1);
+			if (!compressed)
+				btrfs_writepage_endio_finish_ordered(page, cur,
+							    cur + iosize - 1,
+							    NULL, 1);
 			else if (compressed) {
 				/* we don't want to end_page_writeback on
 				 * a compressed extent.  this happens
@@ -4079,10 +4071,9 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
 		if (clear_page_dirty_for_io(page))
 			ret = __extent_writepage(page, &wbc_writepages, &epd);
 		else {
-			if (tree->ops && tree->ops->writepage_end_io_hook)
-				tree->ops->writepage_end_io_hook(page, start,
-						 start + PAGE_SIZE - 1,
-						 NULL, 1);
+			btrfs_writepage_endio_finish_ordered(page, start,
+						    start + PAGE_SIZE - 1,
+						    NULL, 1);
 			unlock_page(page);
 		}
 		put_page(page);

fs/btrfs/extent_io.h

@@ -106,8 +106,6 @@ struct extent_io_ops {
 	/*
 	 * Optional hooks, called if the pointer is not NULL
 	 */
-	void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
-				      struct extent_state *state, int uptodate);
 	void (*set_bit_hook)(void *private_data, struct extent_state *state,
 			     unsigned *bits);
 	void (*clear_bit_hook)(void *private_data,

fs/btrfs/inode.c

@@ -847,14 +847,14 @@ static noinline void submit_compressed_extents(struct inode *inode,
 				    ins.offset, async_extent->pages,
 				    async_extent->nr_pages,
 				    async_cow->write_flags)) {
-			struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
 			struct page *p = async_extent->pages[0];
 			const u64 start = async_extent->start;
 			const u64 end = start + async_extent->ram_size - 1;
 
 			p->mapping = inode->i_mapping;
-			tree->ops->writepage_end_io_hook(p, start, end,
-							 NULL, 0);
+			btrfs_writepage_endio_finish_ordered(p, start, end,
+							     NULL, 0);
+
 			p->mapping = NULL;
 			extent_clear_unlock_delalloc(inode, start, end, end,
 						     NULL, 0,
@@ -3159,7 +3159,7 @@ static void finish_ordered_fn(struct btrfs_work *work)
 	btrfs_finish_ordered_io(ordered_extent);
 }
 
-static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
+void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start, u64 end,
 				struct extent_state *state, int uptodate)
 {
 	struct inode *inode = page->mapping->host;
@@ -10526,7 +10526,6 @@ static const struct extent_io_ops btrfs_extent_io_ops = {
 	.readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
 
 	/* optional callbacks */
-	.writepage_end_io_hook = btrfs_writepage_end_io_hook,
 	.set_bit_hook = btrfs_set_bit_hook,
 	.clear_bit_hook = btrfs_clear_bit_hook,
 	.merge_extent_hook = btrfs_merge_extent_hook,