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/* 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 "ulist.h"
/* bits for the extent state */
#define EXTENT_DIRTY (1U << 0)
#define EXTENT_WRITEBACK (1U << 1)
#define EXTENT_UPTODATE (1U << 2)
#define EXTENT_LOCKED (1U << 3)
#define EXTENT_NEW (1U << 4)
#define EXTENT_DELALLOC (1U << 5)
#define EXTENT_DEFRAG (1U << 6)
#define EXTENT_BOUNDARY (1U << 9)
#define EXTENT_NODATASUM (1U << 10)
#define EXTENT_CLEAR_META_RESV (1U << 11)
#define EXTENT_FIRST_DELALLOC (1U << 12)
#define EXTENT_NEED_WAIT (1U << 13)
#define EXTENT_DAMAGED (1U << 14)
#define EXTENT_NORESERVE (1U << 15)
#define EXTENT_QGROUP_RESERVED (1U << 16)
#define EXTENT_CLEAR_DATA_RESV (1U << 17)
#define EXTENT_DELALLOC_NEW (1U << 18)
#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
#define EXTENT_DO_ACCOUNTING (EXTENT_CLEAR_META_RESV | \
EXTENT_CLEAR_DATA_RESV)
#define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
/*
* flags for bio submission. The high bits indicate the compression
* type for this bio
*/
#define EXTENT_BIO_COMPRESSED 1
#define EXTENT_BIO_FLAG_SHIFT 16
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,
};
/* these are flags for __process_pages_contig */
#define PAGE_UNLOCK (1 << 0)
#define PAGE_CLEAR_DIRTY (1 << 1)
#define PAGE_SET_WRITEBACK (1 << 2)
#define PAGE_END_WRITEBACK (1 << 3)
#define PAGE_SET_PRIVATE2 (1 << 4)
#define PAGE_SET_ERROR (1 << 5)
#define PAGE_LOCK (1 << 6)
/*
* page->private values. Every page that is controlled by the extent
* map has page->private set to one.
*/
#define EXTENT_PAGE_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 extent_state;
struct btrfs_root;
struct btrfs_inode;
struct btrfs_io_bio;
struct io_failure_record;
typedef blk_status_t (extent_submit_bio_hook_t)(void *private_data, struct bio *bio,
int mirror_num, unsigned long bio_flags,
u64 bio_offset);
typedef blk_status_t (extent_submit_bio_start_t)(void *private_data,
struct bio *bio, u64 bio_offset);
struct extent_io_ops {
/*
* The following callbacks must be allways defined, the function
* pointer will be called unconditionally.
*/
extent_submit_bio_hook_t *submit_bio_hook;
int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,
struct page *page, u64 start, u64 end,
int mirror);
};
struct extent_io_tree {
struct rb_root state;
void *private_data;
u64 dirty_bytes;
int track_uptodate;
spinlock_t lock;
const struct extent_io_ops *ops;
};
struct extent_state {
u64 start;
u64 end; /* inclusive */
struct rb_node rb_node;
/* ADD NEW ELEMENTS AFTER THIS */
wait_queue_head_t wq;
refcount_t refs;
unsigned state;
struct io_failure_record *failrec;
#ifdef CONFIG_BTRFS_DEBUG
struct list_head leak_list;
#endif
};
#define INLINE_EXTENT_BUFFER_PAGES 16
#define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE)
struct extent_buffer {
u64 start;
unsigned long len;
unsigned long bflags;
struct btrfs_fs_info *fs_info;
spinlock_t refs_lock;
atomic_t refs;
atomic_t io_pages;
int read_mirror;
struct rcu_head rcu_head;
pid_t lock_owner;
/* count of read lock holders on the extent buffer */
atomic_t write_locks;
atomic_t read_locks;
atomic_t blocking_writers;
atomic_t blocking_readers;
atomic_t spinning_readers;
atomic_t spinning_writers;
short lock_nested;
/* >= 0 if eb belongs to a log tree, -1 otherwise */
short log_index;
/* protects write locks */
rwlock_t lock;
/* readers use lock_wq while they wait for the write
* lock holders to unlock
*/
wait_queue_head_t write_lock_wq;
/* writers use read_lock_wq while they wait for readers
* to unlock
*/
wait_queue_head_t read_lock_wq;
struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
#ifdef CONFIG_BTRFS_DEBUG
struct list_head leak_list;
#endif
};
/*
* Structure to record how many bytes and which ranges are set/cleared
*/
struct extent_changeset {
/* How many bytes are set/cleared in this operation */
unsigned int 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);
}
static inline void extent_set_compress_type(unsigned long *bio_flags,
int compress_type)
{
*bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT;
}
static inline int extent_compress_type(unsigned long bio_flags)
{
return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
}
struct extent_map_tree;
typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
struct page *page,
size_t pg_offset,
u64 start, u64 len,
int create);
void extent_io_tree_init(struct extent_io_tree *tree, void *private_data);
int try_release_extent_mapping(struct page *page, gfp_t mask);
int try_release_extent_buffer(struct page *page);
int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
struct extent_state **cached);
static inline int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
{
return lock_extent_bits(tree, start, end, NULL);
}
int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
get_extent_t *get_extent, int mirror_num);
int __init extent_io_init(void);
void __cold extent_io_exit(void);
u64 count_range_bits(struct extent_io_tree *tree,
u64 *start, u64 search_end,
u64 max_bytes, unsigned bits, int contig);
void free_extent_state(struct extent_state *state);
int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
unsigned bits, int filled,
struct extent_state *cached_state);
int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
unsigned bits, struct extent_changeset *changeset);
int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
unsigned bits, int wake, int delete,
struct extent_state **cached);
int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
unsigned bits, int wake, int delete,
struct extent_state **cached, gfp_t mask,
struct extent_changeset *changeset);
static inline int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end)
{
return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL);
}
static inline int unlock_extent_cached(struct extent_io_tree *tree, u64 start,
u64 end, struct extent_state **cached)
{
return __clear_extent_bit(tree, start, end
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