[deliverable/linux.git] / fs / btrfs / extent_io.h

#ifndef __EXTENTIO__
#define __EXTENTIO__

#include <linux/rbtree.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_DO_ACCOUNTING	(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_IOBITS		(EXTENT_LOCKED | EXTENT_WRITEBACK)
#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_TREE_LOG 2
#define EXTENT_BIO_PARENT_LOCKED 4
#define EXTENT_BIO_FLAG_SHIFT 16

/* these are bit numbers for test/set bit */
#define EXTENT_BUFFER_UPTODATE 0
#define EXTENT_BUFFER_DIRTY 2
#define EXTENT_BUFFER_CORRUPT 3
#define EXTENT_BUFFER_READAHEAD 4	/* this got triggered by readahead */
#define EXTENT_BUFFER_TREE_REF 5
#define EXTENT_BUFFER_STALE 6
#define EXTENT_BUFFER_WRITEBACK 7
#define EXTENT_BUFFER_READ_ERR 8        /* read IO error */
#define EXTENT_BUFFER_DUMMY 9
#define EXTENT_BUFFER_IN_TREE 10
#define EXTENT_BUFFER_WRITE_ERR 11    /* write IO error */

/* these are flags for extent_clear_unlock_delalloc */
#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)

/*
 * page->private values.  Every page that is controlled by the extent
 * map has page->private set to one.
 */
#define EXTENT_PAGE_PRIVATE 1

struct extent_state;
struct btrfs_root;
struct btrfs_io_bio;

typedef	int (extent_submit_bio_hook_t)(struct inode *inode, int rw,
				       struct bio *bio, int mirror_num,
				       unsigned long bio_flags, u64 bio_offset);
struct extent_io_ops {
	int (*fill_delalloc)(struct inode *inode, struct page *locked_page,
			     u64 start, u64 end, int *page_started,
			     unsigned long *nr_written);
	int (*writepage_start_hook)(struct page *page, u64 start, u64 end);
	int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
	extent_submit_bio_hook_t *submit_bio_hook;
	int (*merge_bio_hook)(int rw, struct page *page, unsigned long offset,
			      size_t size, struct bio *bio,
			      unsigned long bio_flags);
	int (*readpage_io_failed_hook)(struct page *page, int failed_mirror);
	int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,
				    struct page *page, u64 start, u64 end,
				    int mirror);
	int (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
				      struct extent_state *state, int uptodate);
	void (*set_bit_hook)(struct inode *inode, struct extent_state *state,
			     unsigned *bits);
	void (*clear_bit_hook)(struct inode *inode, struct extent_state *state,
			       unsigned *bits);
	void (*merge_extent_hook)(struct inode *inode,
				  struct extent_state *new,
				  struct extent_state *other);
	void (*split_extent_hook)(struct inode *inode,
				  struct extent_state *orig, u64 split);
};

struct extent_io_tree {
	struct rb_root state;
	struct address_space *mapping;
	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;
	atomic_t refs;
	unsigned state;

	/* for use by the FS */
	u64 private;

#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_CACHE_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
};

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 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,
			 struct address_space *mapping);
int try_release_extent_mapping(struct extent_map_tree *map,
			       struct extent_io_tree *tree, struct page *page,
			       gfp_t mask);
int try_release_extent_buffer(struct page *page);
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
		     unsigned bits, struct extent_state **cached);
int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end);
int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
			 struct extent_state **cached, gfp_t mask);
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 extent_read_full_page_nolock(struct extent_io_tree *tree, struct page *page,
				 get_extent_t *get_extent, int mirror_num);
int __init extent_io_init(void);
void 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_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
		      unsigned bits, gfp_t mask);
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);
int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
		    unsigned bits, gfp_t mask);
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
		   unsigned bits, u64 *failed_start,
		   struct extent_state **cached_state, gfp_t mask);
int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
			struct extent_state **cached_state, gfp_t mask);
int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
			  struct extent_state **cached_state, gfp_t mask);
int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
		   gfp_t mask);
int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
		     gfp_t mask);
int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
		       gfp_t mask);
int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
		       unsigned bits, unsigned clear_bits,
		       struct extent_state **cached_state, gfp_t mask);
int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
			struct extent_state **cached_state, gfp_t mask);
int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
		      struct extent_state **cached_state, gfp_t mask);
int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
			  u64 *start_ret, u64 *end_ret, unsigned bits,
			  struct extent_state **cached_state);
int extent_invalidatepage(struct extent_io_tree *tree,
			  struct page *page, unsigned long offset);
int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
			  get_extent_t *get_extent,
			  struct writeback_control *wbc);
int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
			      u64 start, u64 end, get_extent_t *get_extent,
			      int mode);
int extent_writepages(struct extent_io_tree *tree,
		      struct address_space *mapping,
		      get_extent_t *get_extent,
		      struct writeback_control *wbc);
int btree_write_cache_pages(struct address_space *mapping,
			    struct writeback_control *wbc);
int extent_readpages(struct extent_io_tree *tree,
		     struct address_space *mapping,
		     struct list_head *pages, unsigned nr_pages,
		     get_extent_t get_extent);
int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
		__u64 start, __u64 len, get_extent_t *get_extent);
int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private);
void set_page_extent_mapped(struct page *page);

struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
					  u64 start);
struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
		u64 start);
struct extent_buffer *btrfs_clone_extent_buffer(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_io_tree *tree,
			     struct extent_buffer *eb, u64 start, int wait,
			     get_extent_t *get_extent, int mirror_num);
void wait_on_extent_buffer_writeback(struct extent_buffer *eb);

static inline unsigned long num_extent_pages(u64 start, u64 len)
{
	return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
		(start >> PAGE_CACHE_SHIFT);
}

static inline void extent_buffer_get(struct extent_buffer *eb)
{
	atomic_inc(&eb->refs);
}

int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
			  unsigned long start,
			  unsigned long len);
void read_extent_buffer(struct extent_buffer *eb, void *dst,
			unsigned long start,
			unsigned long len);
int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dst,
			       unsigned long start,
			       unsigned long len);
void write_extent_buffer(struct extent_buffer *eb, const void *src,
			 unsigned long start, unsigned long len);
void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
			unsigned long dst_offset, unsigned long src_offset,
			unsigned long len);
void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
			   unsigned long src_offset, unsigned long len);
void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
			   unsigned long src_offset, unsigned long len);
void memset_extent_buffer(struct extent_buffer *eb, char c,
			  unsigned long start, unsigned long len);
int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
			   unsigned long pos);
void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
			      unsigned long pos, unsigned long len);
void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
				unsigned long pos, unsigned long len);
void clear_extent_buffer_dirty(struct extent_buffer *eb);
int set_extent_buffer_dirty(struct extent_buffer *eb);
int set_extent_buffer_uptodate(struct extent_buffer *eb);
int clear_extent_buffer_uptodate(struct extent_buffer *eb);
int extent_buffer_uptodate(struct extent_buffer *eb);
int extent_buffer_under_io(struct extent_buffer *eb);
int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset,
		      unsigned long min_len, char **map,
		      unsigned long *map_start,
		      unsigned long *map_len);
int extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
int extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
				 struct page *locked_page,
				 unsigned bits_to_clear,
				 unsigned long page_ops);
struct bio *
btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
		gfp_t gfp_flags);
struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs);
struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask);

struct btrfs_fs_info;

int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical,
		      struct page *page, unsigned int pg_offset,
		      int mirror_num);
int clean_io_failure(struct inode *inode, u64 start, struct page *page,
		     unsigned int pg_offset);
int end_extent_writepage(struct page *page, int err, u64 start, u64 end);
int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
			 int mirror_num);

/*
 * When IO fails, either with EIO or csum verification fails, we
 * try other mirrors that might have a good copy of the data.  This
 * io_failure_record is used to record state as we go through all the
 * mirrors.  If another mirror has good data, the page is set up to date
 * and things continue.  If a good mirror can't be found, the original
 * bio end_io callback is called to indicate things have failed.
 */
struct io_failure_record {
	struct page *page;
	u64 start;
	u64 len;
	u64 logical;
	unsigned long bio_flags;
	int this_mirror;
	int failed_mirror;
	int in_validation;
};

void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end);
int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
				struct io_failure_record **failrec_ret);
int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
			   struct io_failure_record *failrec, int fail_mirror);
struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
				    struct io_failure_record *failrec,
				    struct page *page, int pg_offset, int icsum,
				    bio_end_io_t *endio_func, void *data);
int free_io_failure(struct inode *inode, struct io_failure_record *rec);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
noinline u64 find_lock_delalloc_range(struct inode *inode,
				      struct extent_io_tree *tree,
				      struct page *locked_page, u64 *start,
				      u64 *end, u64 max_bytes);
#endif
struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
					       u64 start);
#endif
Commit	Line	Data
	1	#ifndef __EXTENTIO__
	2	#define __EXTENTIO__
	3
	4	#include <linux/rbtree.h>
	5
	6	/* bits for the extent state */
	7	#define EXTENT_DIRTY (1U << 0)
	8	#define EXTENT_WRITEBACK (1U << 1)
	9	#define EXTENT_UPTODATE (1U << 2)
	10	#define EXTENT_LOCKED (1U << 3)
	11	#define EXTENT_NEW (1U << 4)
	12	#define EXTENT_DELALLOC (1U << 5)
	13	#define EXTENT_DEFRAG (1U << 6)
	14	#define EXTENT_BOUNDARY (1U << 9)
	15	#define EXTENT_NODATASUM (1U << 10)
	16	#define EXTENT_DO_ACCOUNTING (1U << 11)
	17	#define EXTENT_FIRST_DELALLOC (1U << 12)
	18	#define EXTENT_NEED_WAIT (1U << 13)
	19	#define EXTENT_DAMAGED (1U << 14)
	20	#define EXTENT_NORESERVE (1U << 15)
	21	#define EXTENT_IOBITS (EXTENT_LOCKED \| EXTENT_WRITEBACK)
	22	#define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING \| EXTENT_FIRST_DELALLOC)
	23
	24	/*
	25	* flags for bio submission. The high bits indicate the compression
	26	* type for this bio
	27	*/
	28	#define EXTENT_BIO_COMPRESSED 1
	29	#define EXTENT_BIO_TREE_LOG 2
	30	#define EXTENT_BIO_PARENT_LOCKED 4
	31	#define EXTENT_BIO_FLAG_SHIFT 16
	32
	33	/* these are bit numbers for test/set bit */
	34	#define EXTENT_BUFFER_UPTODATE 0
	35	#define EXTENT_BUFFER_DIRTY 2
	36	#define EXTENT_BUFFER_CORRUPT 3
	37	#define EXTENT_BUFFER_READAHEAD 4 /* this got triggered by readahead */
	38	#define EXTENT_BUFFER_TREE_REF 5
	39	#define EXTENT_BUFFER_STALE 6
	40	#define EXTENT_BUFFER_WRITEBACK 7
	41	#define EXTENT_BUFFER_READ_ERR 8 /* read IO error */
	42	#define EXTENT_BUFFER_DUMMY 9
	43	#define EXTENT_BUFFER_IN_TREE 10
	44	#define EXTENT_BUFFER_WRITE_ERR 11 /* write IO error */
	45
	46	/* these are flags for extent_clear_unlock_delalloc */
	47	#define PAGE_UNLOCK (1 << 0)
	48	#define PAGE_CLEAR_DIRTY (1 << 1)
	49	#define PAGE_SET_WRITEBACK (1 << 2)
	50	#define PAGE_END_WRITEBACK (1 << 3)
	51	#define PAGE_SET_PRIVATE2 (1 << 4)
	52	#define PAGE_SET_ERROR (1 << 5)
	53
	54	/*
	55	* page->private values. Every page that is controlled by the extent
	56	* map has page->private set to one.
	57	*/
	58	#define EXTENT_PAGE_PRIVATE 1
	59
	60	struct extent_state;
	61	struct btrfs_root;
	62	struct btrfs_io_bio;
	63
	64	typedef int (extent_submit_bio_hook_t)(struct inode *inode, int rw,
	65	struct bio *bio, int mirror_num,
	66	unsigned long bio_flags, u64 bio_offset);
	67	struct extent_io_ops {
	68	int (fill_delalloc)(struct inode inode, struct page *locked_page,
	69	u64 start, u64 end, int *page_started,
	70	unsigned long *nr_written);
	71	int (writepage_start_hook)(struct page page, u64 start, u64 end);
	72	int (writepage_io_hook)(struct page page, u64 start, u64 end);
	73	extent_submit_bio_hook_t *submit_bio_hook;
	74	int (merge_bio_hook)(int rw, struct page page, unsigned long offset,
	75	size_t size, struct bio *bio,
	76	unsigned long bio_flags);
	77	int (readpage_io_failed_hook)(struct page page, int failed_mirror);
	78	int (readpage_end_io_hook)(struct btrfs_io_bio io_bio, u64 phy_offset,
	79	struct page *page, u64 start, u64 end,
	80	int mirror);
	81	int (writepage_end_io_hook)(struct page page, u64 start, u64 end,
	82	struct extent_state *state, int uptodate);
	83	void (set_bit_hook)(struct inode inode, struct extent_state *state,
	84	unsigned *bits);
	85	void (clear_bit_hook)(struct inode inode, struct extent_state *state,
	86	unsigned *bits);
	87	void (merge_extent_hook)(struct inode inode,
	88	struct extent_state *new,
	89	struct extent_state *other);
	90	void (split_extent_hook)(struct inode inode,
	91	struct extent_state *orig, u64 split);
	92	};
	93
	94	struct extent_io_tree {
	95	struct rb_root state;
	96	struct address_space *mapping;
	97	u64 dirty_bytes;
	98	int track_uptodate;
	99	spinlock_t lock;
	100	const struct extent_io_ops *ops;
	101	};
	102
	103	struct extent_state {
	104	u64 start;
	105	u64 end; /* inclusive */
	106	struct rb_node rb_node;
	107
	108	/* ADD NEW ELEMENTS AFTER THIS */
	109	wait_queue_head_t wq;
	110	atomic_t refs;
	111	unsigned state;
	112
	113	/* for use by the FS */
	114	u64 private;
	115
	116	#ifdef CONFIG_BTRFS_DEBUG
	117	struct list_head leak_list;
	118	#endif
	119	};
	120
	121	#define INLINE_EXTENT_BUFFER_PAGES 16
	122	#define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_CACHE_SIZE)
	123	struct extent_buffer {
	124	u64 start;
	125	unsigned long len;
	126	unsigned long bflags;
	127	struct btrfs_fs_info *fs_info;
	128	spinlock_t refs_lock;
	129	atomic_t refs;
	130	atomic_t io_pages;
	131	int read_mirror;
	132	struct rcu_head rcu_head;
	133	pid_t lock_owner;
	134
	135	/* count of read lock holders on the extent buffer */
	136	atomic_t write_locks;
	137	atomic_t read_locks;
	138	atomic_t blocking_writers;
	139	atomic_t blocking_readers;
	140	atomic_t spinning_readers;
	141	atomic_t spinning_writers;
	142	short lock_nested;
	143	/* >= 0 if eb belongs to a log tree, -1 otherwise */
	144	short log_index;
	145
	146	/* protects write locks */
	147	rwlock_t lock;
	148
	149	/* readers use lock_wq while they wait for the write
	150	* lock holders to unlock
	151	*/
	152	wait_queue_head_t write_lock_wq;
	153
	154	/* writers use read_lock_wq while they wait for readers
	155	* to unlock
	156	*/
	157	wait_queue_head_t read_lock_wq;
	158	struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
	159	#ifdef CONFIG_BTRFS_DEBUG
	160	struct list_head leak_list;
	161	#endif
	162	};
	163
	164	static inline void extent_set_compress_type(unsigned long *bio_flags,
	165	int compress_type)
	166	{
	167	*bio_flags \|= compress_type << EXTENT_BIO_FLAG_SHIFT;
	168	}
	169
	170	static inline int extent_compress_type(unsigned long bio_flags)
	171	{
	172	return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
	173	}
	174
	175	struct extent_map_tree;
	176
	177	typedef struct extent_map (get_extent_t)(struct inode inode,
	178	struct page *page,
	179	size_t pg_offset,
	180	u64 start, u64 len,
	181	int create);
	182
	183	void extent_io_tree_init(struct extent_io_tree *tree,
	184	struct address_space *mapping);
	185	int try_release_extent_mapping(struct extent_map_tree *map,
	186	struct extent_io_tree tree, struct page page,
	187	gfp_t mask);
	188	int try_release_extent_buffer(struct page *page);
	189	int lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
	190	int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
	191	unsigned bits, struct extent_state **cached);
	192	int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end);
	193	int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
	194	struct extent_state **cached, gfp_t mask);
	195	int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
	196	int extent_read_full_page(struct extent_io_tree tree, struct page page,
	197	get_extent_t *get_extent, int mirror_num);
	198	int extent_read_full_page_nolock(struct extent_io_tree tree, struct page page,
	199	get_extent_t *get_extent, int mirror_num);
	200	int __init extent_io_init(void);
	201	void extent_io_exit(void);
	202
	203	u64 count_range_bits(struct extent_io_tree *tree,
	204	u64 *start, u64 search_end,
	205	u64 max_bytes, unsigned bits, int contig);
	206
	207	void free_extent_state(struct extent_state *state);
	208	int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
	209	unsigned bits, int filled,
	210	struct extent_state *cached_state);
	211	int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
	212	unsigned bits, gfp_t mask);
	213	int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
	214	unsigned bits, int wake, int delete,
	215	struct extent_state **cached, gfp_t mask);
	216	int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
	217	unsigned bits, gfp_t mask);
	218	int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
	219	unsigned bits, u64 *failed_start,
	220	struct extent_state **cached_state, gfp_t mask);
	221	int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
	222	struct extent_state **cached_state, gfp_t mask);
	223	int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
	224	struct extent_state **cached_state, gfp_t mask);
	225	int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
	226	gfp_t mask);
	227	int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
	228	gfp_t mask);
	229	int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
	230	gfp_t mask);
	231	int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
	232	unsigned bits, unsigned clear_bits,
	233	struct extent_state **cached_state, gfp_t mask);
	234	int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
	235	struct extent_state **cached_state, gfp_t mask);
	236	int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
	237	struct extent_state **cached_state, gfp_t mask);
	238	int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
	239	u64 start_ret, u64 end_ret, unsigned bits,
	240	struct extent_state **cached_state);
	241	int extent_invalidatepage(struct extent_io_tree *tree,
	242	struct page *page, unsigned long offset);
	243	int extent_write_full_page(struct extent_io_tree tree, struct page page,
	244	get_extent_t *get_extent,
	245	struct writeback_control *wbc);
	246	int extent_write_locked_range(struct extent_io_tree tree, struct inode inode,
	247	u64 start, u64 end, get_extent_t *get_extent,
	248	int mode);
	249	int extent_writepages(struct extent_io_tree *tree,
	250	struct address_space *mapping,
	251	get_extent_t *get_extent,
	252	struct writeback_control *wbc);
	253	int btree_write_cache_pages(struct address_space *mapping,
	254	struct writeback_control *wbc);
	255	int extent_readpages(struct extent_io_tree *tree,
	256	struct address_space *mapping,
	257	struct list_head *pages, unsigned nr_pages,
	258	get_extent_t get_extent);
	259	int extent_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
	260	__u64 start, __u64 len, get_extent_t *get_extent);
	261	int get_state_private(struct extent_io_tree tree, u64 start, u64 private);
	262	void set_page_extent_mapped(struct page *page);
	263
	264	struct extent_buffer alloc_extent_buffer(struct btrfs_fs_info fs_info,
	265	u64 start);
	266	struct extent_buffer alloc_dummy_extent_buffer(struct btrfs_fs_info fs_info,
	267	u64 start);
	268	struct extent_buffer btrfs_clone_extent_buffer(struct extent_buffer src);
	269	struct extent_buffer find_extent_buffer(struct btrfs_fs_info fs_info,
	270	u64 start);
	271	void free_extent_buffer(struct extent_buffer *eb);
	272	void free_extent_buffer_stale(struct extent_buffer *eb);
	273	#define WAIT_NONE 0
	274	#define WAIT_COMPLETE 1
	275	#define WAIT_PAGE_LOCK 2
	276	int read_extent_buffer_pages(struct extent_io_tree *tree,
	277	struct extent_buffer *eb, u64 start, int wait,
	278	get_extent_t *get_extent, int mirror_num);
	279	void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
	280
	281	static inline unsigned long num_extent_pages(u64 start, u64 len)
	282	{
	283	return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
	284	(start >> PAGE_CACHE_SHIFT);
	285	}
	286
	287	static inline void extent_buffer_get(struct extent_buffer *eb)
	288	{
	289	atomic_inc(&eb->refs);
	290	}
	291
	292	int memcmp_extent_buffer(struct extent_buffer eb, const void ptrv,
	293	unsigned long start,
	294	unsigned long len);
	295	void read_extent_buffer(struct extent_buffer eb, void dst,
	296	unsigned long start,
	297	unsigned long len);
	298	int read_extent_buffer_to_user(struct extent_buffer eb, void __user dst,
	299	unsigned long start,
	300	unsigned long len);
	301	void write_extent_buffer(struct extent_buffer eb, const void src,
	302	unsigned long start, unsigned long len);
	303	void copy_extent_buffer(struct extent_buffer dst, struct extent_buffer src,
	304	unsigned long dst_offset, unsigned long src_offset,
	305	unsigned long len);
	306	void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
	307	unsigned long src_offset, unsigned long len);
	308	void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
	309	unsigned long src_offset, unsigned long len);
	310	void memset_extent_buffer(struct extent_buffer *eb, char c,
	311	unsigned long start, unsigned long len);
	312	int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
	313	unsigned long pos);
	314	void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
	315	unsigned long pos, unsigned long len);
	316	void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
	317	unsigned long pos, unsigned long len);
	318	void clear_extent_buffer_dirty(struct extent_buffer *eb);
	319	int set_extent_buffer_dirty(struct extent_buffer *eb);
	320	int set_extent_buffer_uptodate(struct extent_buffer *eb);
	321	int clear_extent_buffer_uptodate(struct extent_buffer *eb);
	322	int extent_buffer_uptodate(struct extent_buffer *eb);
	323	int extent_buffer_under_io(struct extent_buffer *eb);
	324	int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset,
	325	unsigned long min_len, char **map,
	326	unsigned long *map_start,
	327	unsigned long *map_len);
	328	int extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
	329	int extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
	330	int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
	331	struct page *locked_page,
	332	unsigned bits_to_clear,
	333	unsigned long page_ops);
	334	struct bio *
	335	btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
	336	gfp_t gfp_flags);
	337	struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs);
	338	struct bio btrfs_bio_clone(struct bio bio, gfp_t gfp_mask);
	339
	340	struct btrfs_fs_info;
	341
	342	int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical,
	343	struct page *page, unsigned int pg_offset,
	344	int mirror_num);
	345	int clean_io_failure(struct inode inode, u64 start, struct page page,
	346	unsigned int pg_offset);
	347	int end_extent_writepage(struct page *page, int err, u64 start, u64 end);
	348	int repair_eb_io_failure(struct btrfs_root root, struct extent_buffer eb,
	349	int mirror_num);
	350
	351	/*
	352	* When IO fails, either with EIO or csum verification fails, we
	353	* try other mirrors that might have a good copy of the data. This
	354	* io_failure_record is used to record state as we go through all the
	355	* mirrors. If another mirror has good data, the page is set up to date
	356	* and things continue. If a good mirror can't be found, the original
	357	* bio end_io callback is called to indicate things have failed.
	358	*/
	359	struct io_failure_record {
	360	struct page *page;
	361	u64 start;
	362	u64 len;
	363	u64 logical;
	364	unsigned long bio_flags;
	365	int this_mirror;
	366	int failed_mirror;
	367	int in_validation;
	368	};
	369
	370	void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end);
	371	int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
	372	struct io_failure_record **failrec_ret);
	373	int btrfs_check_repairable(struct inode inode, struct bio failed_bio,
	374	struct io_failure_record *failrec, int fail_mirror);
	375	struct bio btrfs_create_repair_bio(struct inode inode, struct bio *failed_bio,
	376	struct io_failure_record *failrec,
	377	struct page *page, int pg_offset, int icsum,
	378	bio_end_io_t endio_func, void data);
	379	int free_io_failure(struct inode inode, struct io_failure_record rec);
	380	#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
	381	noinline u64 find_lock_delalloc_range(struct inode *inode,
	382	struct extent_io_tree *tree,
	383	struct page locked_page, u64 start,
	384	u64 *end, u64 max_bytes);
	385	#endif
	386	struct extent_buffer alloc_test_extent_buffer(struct btrfs_fs_info fs_info,
	387	u64 start);
	388	#endif