Commit 651fb419 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: subpage: make btrfs_alloc_subpage() return btrfs_subpage directly 



The existing calling convention of btrfs_alloc_subpage() is pretty
awful.  Change it to a more common pattern by returning struct
btrfs_subpage directly and let the caller to determine if the call
succeeded.

Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent fdf250db

fs/btrfs/extent_io.c

+3 −3
Original line number Diff line number Diff line
@@ -6138,9 +6138,9 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 
		 * support, so we still preallocate the memory in the loop.

		 */

		if (fs_info->sectorsize < PAGE_SIZE) {

			ret = btrfs_alloc_subpage(fs_info, &prealloc,

						  BTRFS_SUBPAGE_METADATA);

			if (ret < 0) {

			prealloc = btrfs_alloc_subpage(fs_info, BTRFS_SUBPAGE_METADATA);

			if (IS_ERR(prealloc)) {

				ret = PTR_ERR(prealloc);

				unlock_page(p);

				put_page(p);

				exists = ERR_PTR(ret);

fs/btrfs/subpage.c

+19 −16
Original line number Diff line number Diff line
@@ -66,8 +66,7 @@ 
int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,

			 struct page *page, enum btrfs_subpage_type type)

{

	struct btrfs_subpage *subpage = NULL;

	int ret;

	struct btrfs_subpage *subpage;



	/*

	 * We have cases like a dummy extent buffer page, which is not mappped
@@ -75,13 +74,15 @@ int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info, 
	 */

	if (page->mapping)

		ASSERT(PageLocked(page));



	/* Either not subpage, or the page already has private attached */

	if (fs_info->sectorsize == PAGE_SIZE || PagePrivate(page))

		return 0;



	ret = btrfs_alloc_subpage(fs_info, &subpage, type);

	if (ret < 0)

		return ret;

	subpage = btrfs_alloc_subpage(fs_info, type);

	if (IS_ERR(subpage))

		return  PTR_ERR(subpage);



	attach_page_private(page, subpage);

	return 0;

}
@@ -100,23 +101,25 @@ void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info, 
	btrfs_free_subpage(subpage);

}



int btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,

			struct btrfs_subpage **ret,

struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,

					  enum btrfs_subpage_type type)

{

	struct btrfs_subpage *ret;



	ASSERT(fs_info->sectorsize < PAGE_SIZE);



	*ret = kzalloc(sizeof(struct btrfs_subpage), GFP_NOFS);

	if (!*ret)

		return -ENOMEM;

	spin_lock_init(&(*ret)->lock);

	ret = kzalloc(sizeof(struct btrfs_subpage), GFP_NOFS);

	if (!ret)

		return ERR_PTR(-ENOMEM);



	spin_lock_init(&ret->lock);

	if (type == BTRFS_SUBPAGE_METADATA) {

		atomic_set(&(*ret)->eb_refs, 0);

		atomic_set(&ret->eb_refs, 0);

	} else {

		atomic_set(&(*ret)->readers, 0);

		atomic_set(&(*ret)->writers, 0);

		atomic_set(&ret->readers, 0);

		atomic_set(&ret->writers, 0);

	}

	return 0;

	return ret;

}



void btrfs_free_subpage(struct btrfs_subpage *subpage)

fs/btrfs/subpage.h

+2 −3
Original line number Diff line number Diff line
@@ -59,8 +59,7 @@ void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info, 
			  struct page *page);



/* Allocate additional data where page represents more than one sector */

int btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,

			struct btrfs_subpage **ret,

struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,

					  enum btrfs_subpage_type type);

void btrfs_free_subpage(struct btrfs_subpage *subpage);