mirror of https://gitee.com/openkylin/linux.git
92 lines
2.9 KiB
C
92 lines
2.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
|
|
#ifndef BTRFS_SUBPAGE_H
|
|
#define BTRFS_SUBPAGE_H
|
|
|
|
#include <linux/spinlock.h>
|
|
|
|
/*
|
|
* Maximum page size we support is 64K, minimum sector size is 4K, u16 bitmap
|
|
* is sufficient. Regular bitmap_* is not used due to size reasons.
|
|
*/
|
|
#define BTRFS_SUBPAGE_BITMAP_SIZE 16
|
|
|
|
/*
|
|
* Structure to trace status of each sector inside a page, attached to
|
|
* page::private for both data and metadata inodes.
|
|
*/
|
|
struct btrfs_subpage {
|
|
/* Common members for both data and metadata pages */
|
|
spinlock_t lock;
|
|
u16 uptodate_bitmap;
|
|
u16 error_bitmap;
|
|
union {
|
|
/*
|
|
* Structures only used by metadata
|
|
*
|
|
* @eb_refs should only be operated under private_lock, as it
|
|
* manages whether the subpage can be detached.
|
|
*/
|
|
atomic_t eb_refs;
|
|
/* Structures only used by data */
|
|
struct {
|
|
atomic_t readers;
|
|
};
|
|
};
|
|
};
|
|
|
|
enum btrfs_subpage_type {
|
|
BTRFS_SUBPAGE_METADATA,
|
|
BTRFS_SUBPAGE_DATA,
|
|
};
|
|
|
|
int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, enum btrfs_subpage_type type);
|
|
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,
|
|
enum btrfs_subpage_type type);
|
|
void btrfs_free_subpage(struct btrfs_subpage *subpage);
|
|
|
|
void btrfs_page_inc_eb_refs(const struct btrfs_fs_info *fs_info,
|
|
struct page *page);
|
|
void btrfs_page_dec_eb_refs(const struct btrfs_fs_info *fs_info,
|
|
struct page *page);
|
|
|
|
void btrfs_subpage_start_reader(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 start, u32 len);
|
|
void btrfs_subpage_end_reader(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 start, u32 len);
|
|
|
|
/*
|
|
* Template for subpage related operations.
|
|
*
|
|
* btrfs_subpage_*() are for call sites where the page has subpage attached and
|
|
* the range is ensured to be inside the page.
|
|
*
|
|
* btrfs_page_*() are for call sites where the page can either be subpage
|
|
* specific or regular page. The function will handle both cases.
|
|
* But the range still needs to be inside the page.
|
|
*/
|
|
#define DECLARE_BTRFS_SUBPAGE_OPS(name) \
|
|
void btrfs_subpage_set_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
void btrfs_subpage_clear_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
bool btrfs_subpage_test_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
void btrfs_page_set_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
void btrfs_page_clear_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
bool btrfs_page_test_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len);
|
|
|
|
DECLARE_BTRFS_SUBPAGE_OPS(uptodate);
|
|
DECLARE_BTRFS_SUBPAGE_OPS(error);
|
|
|
|
#endif
|