linux/fs/btrfs/extent_io.h
Qu Wenruo 8d99361835 btrfs: migrate get_eb_page_index() and get_eb_offset_in_page() to folios
These two functions are still using the old page based code, which is
not going to handle larger folios at all.

The migration itself is going to involve the following changes:

- PAGE_SIZE -> folio_size()
- PAGE_SHIFT -> folio_shift()
- get_eb_page_index() -> get_eb_folio_index()
- get_eb_offset_in_page() -> get_eb_offset_in_folio()

And since we're going to support larger folios, although above straight
conversion is good enough, this patch would add extra comments in the
involved functions to explain why the same single line code can now
cover 3 cases:

- folio_size == PAGE_SIZE, sectorsize == PAGE_SIZE, nodesize >= PAGE_SIZE
  The common, non-subpage case with per-page folio.

- folio_size > PAGE_SIZE, sectorsize == PAGE_SIZE, nodesize >= PAGE_SIZE
  The incoming larger folio, non-subpage case.

- folio_size == PAGE_SIZE, sectorsize < PAGE_SIZE, nodesize < PAGE_SIZE
  The existing subpage case, we won't larger folio anyway.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-12-15 23:03:58 +01:00

356 lines
11 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BTRFS_EXTENT_IO_H
#define BTRFS_EXTENT_IO_H
#include <linux/rbtree.h>
#include <linux/refcount.h>
#include <linux/fiemap.h>
#include <linux/btrfs_tree.h>
#include "compression.h"
#include "ulist.h"
#include "misc.h"
struct btrfs_trans_handle;
enum {
EXTENT_BUFFER_UPTODATE,
EXTENT_BUFFER_DIRTY,
EXTENT_BUFFER_CORRUPT,
/* this got triggered by readahead */
EXTENT_BUFFER_READAHEAD,
EXTENT_BUFFER_TREE_REF,
EXTENT_BUFFER_STALE,
EXTENT_BUFFER_WRITEBACK,
/* read IO error */
EXTENT_BUFFER_READ_ERR,
EXTENT_BUFFER_UNMAPPED,
EXTENT_BUFFER_IN_TREE,
/* write IO error */
EXTENT_BUFFER_WRITE_ERR,
/* Indicate the extent buffer is written zeroed out (for zoned) */
EXTENT_BUFFER_ZONED_ZEROOUT,
/* Indicate that extent buffer pages a being read */
EXTENT_BUFFER_READING,
};
/* these are flags for __process_pages_contig */
enum {
ENUM_BIT(PAGE_UNLOCK),
/* Page starts writeback, clear dirty bit and set writeback bit */
ENUM_BIT(PAGE_START_WRITEBACK),
ENUM_BIT(PAGE_END_WRITEBACK),
ENUM_BIT(PAGE_SET_ORDERED),
};
/*
* Folio private values. Every page that is controlled by the extent map has
* folio private set to this value.
*/
#define EXTENT_FOLIO_PRIVATE 1
/*
* The extent buffer bitmap operations are done with byte granularity instead of
* word granularity for two reasons:
* 1. The bitmaps must be little-endian on disk.
* 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
* single word in a bitmap may straddle two pages in the extent buffer.
*/
#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
#define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
#define BITMAP_FIRST_BYTE_MASK(start) \
((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
#define BITMAP_LAST_BYTE_MASK(nbits) \
(BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
struct btrfs_root;
struct btrfs_inode;
struct btrfs_fs_info;
struct extent_io_tree;
struct btrfs_tree_parent_check;
int __init extent_buffer_init_cachep(void);
void __cold extent_buffer_free_cachep(void);
#define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
struct extent_buffer {
u64 start;
unsigned long len;
unsigned long bflags;
struct btrfs_fs_info *fs_info;
/*
* The address where the eb can be accessed without any cross-page handling.
* This can be NULL if not possible.
*/
void *addr;
spinlock_t refs_lock;
atomic_t refs;
int read_mirror;
/* >= 0 if eb belongs to a log tree, -1 otherwise */
s8 log_index;
struct rcu_head rcu_head;
struct rw_semaphore lock;
/*
* Pointers to all the folios of the extent buffer.
*
* For now the folio is always order 0 (aka, a single page).
*/
struct folio *folios[INLINE_EXTENT_BUFFER_PAGES];
#ifdef CONFIG_BTRFS_DEBUG
struct list_head leak_list;
pid_t lock_owner;
#endif
};
struct btrfs_eb_write_context {
struct writeback_control *wbc;
struct extent_buffer *eb;
/* Block group @eb resides in. Only used for zoned mode. */
struct btrfs_block_group *zoned_bg;
};
/*
* Get the correct offset inside the page of extent buffer.
*
* @eb: target extent buffer
* @start: offset inside the extent buffer
*
* Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
*/
static inline size_t get_eb_offset_in_folio(const struct extent_buffer *eb,
unsigned long offset)
{
/*
* 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case
* 1.1) One large folio covering the whole eb
* The eb->start is aligned to folio size, thus adding it
* won't cause any difference.
* 1.2) Several page sized folios
* The eb->start is aligned to folio (page) size, thus
* adding it won't cause any difference.
*
* 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case
* In this case there would only be one page sized folio, and there
* may be several different extent buffers in the page/folio.
* We need to add eb->start to properly access the offset inside
* that eb.
*/
return offset_in_folio(eb->folios[0], offset + eb->start);
}
static inline unsigned long get_eb_folio_index(const struct extent_buffer *eb,
unsigned long offset)
{
/*
* 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case
* 1.1) One large folio covering the whole eb.
* the folio_shift would be large enough to always make us
* return 0 as index.
* 1.2) Several page sized folios
* The folio_shift() would be PAGE_SHIFT, giving us the correct
* index.
*
* 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case
* The folio would only be page sized, and always give us 0 as index.
*/
return offset >> folio_shift(eb->folios[0]);
}
/*
* Structure to record how many bytes and which ranges are set/cleared
*/
struct extent_changeset {
/* How many bytes are set/cleared in this operation */
u64 bytes_changed;
/* Changed ranges */
struct ulist range_changed;
};
static inline void extent_changeset_init(struct extent_changeset *changeset)
{
changeset->bytes_changed = 0;
ulist_init(&changeset->range_changed);
}
static inline struct extent_changeset *extent_changeset_alloc(void)
{
struct extent_changeset *ret;
ret = kmalloc(sizeof(*ret), GFP_KERNEL);
if (!ret)
return NULL;
extent_changeset_init(ret);
return ret;
}
static inline void extent_changeset_release(struct extent_changeset *changeset)
{
if (!changeset)
return;
changeset->bytes_changed = 0;
ulist_release(&changeset->range_changed);
}
static inline void extent_changeset_free(struct extent_changeset *changeset)
{
if (!changeset)
return;
extent_changeset_release(changeset);
kfree(changeset);
}
struct extent_map_tree;
int try_release_extent_mapping(struct page *page, gfp_t mask);
int try_release_extent_buffer(struct page *page);
int btrfs_read_folio(struct file *file, struct folio *folio);
void extent_write_locked_range(struct inode *inode, struct page *locked_page,
u64 start, u64 end, struct writeback_control *wbc,
bool pages_dirty);
int extent_writepages(struct address_space *mapping,
struct writeback_control *wbc);
int btree_write_cache_pages(struct address_space *mapping,
struct writeback_control *wbc);
void extent_readahead(struct readahead_control *rac);
int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len);
int set_page_extent_mapped(struct page *page);
void clear_page_extent_mapped(struct page *page);
struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start, u64 owner_root, int level);
struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start, unsigned long len);
struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start);
struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start);
void free_extent_buffer(struct extent_buffer *eb);
void free_extent_buffer_stale(struct extent_buffer *eb);
#define WAIT_NONE 0
#define WAIT_COMPLETE 1
#define WAIT_PAGE_LOCK 2
int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num,
struct btrfs_tree_parent_check *parent_check);
void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
u64 bytenr, u64 owner_root, u64 gen, int level);
void btrfs_readahead_node_child(struct extent_buffer *node, int slot);
static inline int num_extent_pages(const struct extent_buffer *eb)
{
/*
* For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
* sectorsize, it's just eb->len >> PAGE_SHIFT.
*
* For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
* thus have to ensure we get at least one page.
*/
return (eb->len >> PAGE_SHIFT) ?: 1;
}
/*
* This can only be determined at runtime by checking eb::folios[0].
*
* As we can have either one large folio covering the whole eb
* (either nodesize <= PAGE_SIZE, or high order folio), or multiple
* single-paged folios.
*/
static inline int num_extent_folios(const struct extent_buffer *eb)
{
if (folio_order(eb->folios[0]))
return 1;
return num_extent_pages(eb);
}
static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
{
return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
}
int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
unsigned long start, unsigned long len);
void read_extent_buffer(const struct extent_buffer *eb, void *dst,
unsigned long start,
unsigned long len);
int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
void __user *dst, unsigned long start,
unsigned long len);
void write_extent_buffer(const struct extent_buffer *eb, const void *src,
unsigned long start, unsigned long len);
static inline void write_extent_buffer_chunk_tree_uuid(
const struct extent_buffer *eb, const void *chunk_tree_uuid)
{
write_extent_buffer(eb, chunk_tree_uuid,
offsetof(struct btrfs_header, chunk_tree_uuid),
BTRFS_FSID_SIZE);
}
static inline void write_extent_buffer_fsid(const struct extent_buffer *eb,
const void *fsid)
{
write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
BTRFS_FSID_SIZE);
}
void copy_extent_buffer_full(const struct extent_buffer *dst,
const struct extent_buffer *src);
void copy_extent_buffer(const struct extent_buffer *dst,
const struct extent_buffer *src,
unsigned long dst_offset, unsigned long src_offset,
unsigned long len);
void memcpy_extent_buffer(const struct extent_buffer *dst,
unsigned long dst_offset, unsigned long src_offset,
unsigned long len);
void memmove_extent_buffer(const struct extent_buffer *dst,
unsigned long dst_offset, unsigned long src_offset,
unsigned long len);
void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
unsigned long len);
int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
unsigned long pos);
void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
unsigned long pos, unsigned long len);
void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
unsigned long start, unsigned long pos,
unsigned long len);
void set_extent_buffer_dirty(struct extent_buffer *eb);
void set_extent_buffer_uptodate(struct extent_buffer *eb);
void clear_extent_buffer_uptodate(struct extent_buffer *eb);
void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
struct page *locked_page,
u32 bits_to_clear, unsigned long page_ops);
int extent_invalidate_folio(struct extent_io_tree *tree,
struct folio *folio, size_t offset);
void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
struct extent_buffer *buf);
int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array,
gfp_t extra_gfp);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
bool find_lock_delalloc_range(struct inode *inode,
struct page *locked_page, u64 *start,
u64 *end);
#endif
struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start);
#ifdef CONFIG_BTRFS_DEBUG
void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
#else
#define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0)
#endif
#endif