/* 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 <linux/spinlock.h>
#include <linux/atomic.h>
#include <linux/rwsem.h>
#include <linux/list.h>
#include <linux/slab.h>
#include "compression.h"
#include "messages.h"
#include "ulist.h"
#include "misc.h"
struct page;
struct file;
struct folio;
struct inode;
struct fiemap_extent_info;
struct readahead_control;
struct address_space;
struct writeback_control;
struct extent_io_tree;
struct extent_map_tree;
struct extent_state;
struct btrfs_block_group;
struct btrfs_fs_info;
struct btrfs_inode;
struct btrfs_root;
struct btrfs_trans_handle;
struct btrfs_tree_parent_check;
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)))
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;
u32 len;
u32 folio_size;
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;
u8 folio_shift;
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;
};
static inline unsigned long offset_in_eb_folio(const struct extent_buffer *eb,
u64 start)
{
ASSERT(eb->folio_size);
return start & (eb->folio_size - 1);
}
/*
* 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 >> eb->folio_shift;
}
/*
* 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_prealloc(struct extent_changeset *changeset, gfp_t gfp_mask)
{
ulist_prealloc(&changeset->range_changed, gfp_mask);
}
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);
}
bool try_release_extent_mapping(struct folio *folio, gfp_t mask);
int try_release_extent_buffer(struct folio *folio);
int btrfs_read_folio(struct file *file, struct folio *folio);
void extent_write_locked_range(struct inode *inode, const struct folio *locked_folio,
u64 start, u64 end, struct writeback_control *wbc,
bool pages_dirty);
int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc);
int btree_write_cache_pages(struct address_space *mapping,
struct writeback_control *wbc);
void btrfs_readahead(struct readahead_control *rac);
int set_folio_extent_mapped(struct folio *folio);
int set_page_extent_mapped(struct page *page);
void clear_folio_extent_mapped(struct folio *folio);
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,
const 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_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
const struct folio *locked_folio,
struct extent_state **cached,
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,
bool nofail);
int btrfs_alloc_folio_array(unsigned int nr_folios, struct folio **folio_array);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
bool find_lock_delalloc_range(struct inode *inode,
struct folio *locked_folio, 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
Codebase Browser
linux