[linux-2.6-block.git] / fs / btrfs / extent_io.h

/* 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_TREE_REF,
	EXTENT_BUFFER_STALE,
	EXTENT_BUFFER_WRITEBACK,
	EXTENT_BUFFER_UNMAPPED,
	/* 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 ((1U << 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_btree_wait_writeback_range(struct btrfs_fs_info *fs_info, u64 start, u64 end);
void btrfs_readahead(struct readahead_control *rac);
int set_folio_extent_mapped(struct folio *folio);
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);
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);
int read_extent_buffer_pages(struct extent_buffer *eb, int mirror_num,
			     const struct btrfs_tree_parent_check *parent_check);
int read_extent_buffer_pages_nowait(struct extent_buffer *eb, int mirror_num,
				    const struct btrfs_tree_parent_check *parent_check);

static inline void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
{
	wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
		       TASK_UNINTERRUPTIBLE);
}

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);

/* Note: this can be used in for loops without caching the value in a variable. */
static inline int __pure 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.
 *
 * Note: this can be used in for loops without caching the value in a variable.
 */
static inline int __pure num_extent_folios(const struct extent_buffer *eb)
{
	if (!eb->folios[0])
		return 0;
	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
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2
	3	#ifndef BTRFS_EXTENT_IO_H
	4	#define BTRFS_EXTENT_IO_H
	5
	6	#include <linux/rbtree.h>
	7	#include <linux/refcount.h>
	8	#include <linux/fiemap.h>
	9	#include <linux/btrfs_tree.h>
	10	#include <linux/spinlock.h>
	11	#include <linux/atomic.h>
	12	#include <linux/rwsem.h>
	13	#include <linux/list.h>
	14	#include <linux/slab.h>
	15	#include "compression.h"
	16	#include "messages.h"
	17	#include "ulist.h"
	18	#include "misc.h"
	19
	20	struct page;
	21	struct file;
	22	struct folio;
	23	struct inode;
	24	struct fiemap_extent_info;
	25	struct readahead_control;
	26	struct address_space;
	27	struct writeback_control;
	28	struct extent_io_tree;
	29	struct extent_map_tree;
	30	struct extent_state;
	31	struct btrfs_block_group;
	32	struct btrfs_fs_info;
	33	struct btrfs_inode;
	34	struct btrfs_root;
	35	struct btrfs_trans_handle;
	36	struct btrfs_tree_parent_check;
	37
	38	enum {
	39	EXTENT_BUFFER_UPTODATE,
	40	EXTENT_BUFFER_DIRTY,
	41	EXTENT_BUFFER_TREE_REF,
	42	EXTENT_BUFFER_STALE,
	43	EXTENT_BUFFER_WRITEBACK,
	44	EXTENT_BUFFER_UNMAPPED,
	45	/* write IO error */
	46	EXTENT_BUFFER_WRITE_ERR,
	47	/* Indicate the extent buffer is written zeroed out (for zoned) */
	48	EXTENT_BUFFER_ZONED_ZEROOUT,
	49	/* Indicate that extent buffer pages a being read */
	50	EXTENT_BUFFER_READING,
	51	};
	52
	53	/* these are flags for __process_pages_contig */
	54	enum {
	55	ENUM_BIT(PAGE_UNLOCK),
	56	/* Page starts writeback, clear dirty bit and set writeback bit */
	57	ENUM_BIT(PAGE_START_WRITEBACK),
	58	ENUM_BIT(PAGE_END_WRITEBACK),
	59	ENUM_BIT(PAGE_SET_ORDERED),
	60	};
	61
	62	/*
	63	* Folio private values. Every page that is controlled by the extent map has
	64	* folio private set to this value.
	65	*/
	66	#define EXTENT_FOLIO_PRIVATE 1
	67
	68	/*
	69	* The extent buffer bitmap operations are done with byte granularity instead of
	70	* word granularity for two reasons:
	71	* 1. The bitmaps must be little-endian on disk.
	72	* 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
	73	* single word in a bitmap may straddle two pages in the extent buffer.
	74	*/
	75	#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
	76	#define BYTE_MASK ((1U << BITS_PER_BYTE) - 1)
	77	#define BITMAP_FIRST_BYTE_MASK(start) \
	78	((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
	79	#define BITMAP_LAST_BYTE_MASK(nbits) \
	80	(BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
	81
	82
	83	int __init extent_buffer_init_cachep(void);
	84	void __cold extent_buffer_free_cachep(void);
	85
	86	#define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
	87	struct extent_buffer {
	88	u64 start;
	89	u32 len;
	90	u32 folio_size;
	91	unsigned long bflags;
	92	struct btrfs_fs_info *fs_info;
	93
	94	/*
	95	* The address where the eb can be accessed without any cross-page handling.
	96	* This can be NULL if not possible.
	97	*/
	98	void *addr;
	99
	100	spinlock_t refs_lock;
	101	atomic_t refs;
	102	int read_mirror;
	103	/* >= 0 if eb belongs to a log tree, -1 otherwise */
	104	s8 log_index;
	105	u8 folio_shift;
	106	struct rcu_head rcu_head;
	107
	108	struct rw_semaphore lock;
	109
	110	/*
	111	* Pointers to all the folios of the extent buffer.
	112	*
	113	* For now the folio is always order 0 (aka, a single page).
	114	*/
	115	struct folio *folios[INLINE_EXTENT_BUFFER_PAGES];
	116	#ifdef CONFIG_BTRFS_DEBUG
	117	struct list_head leak_list;
	118	pid_t lock_owner;
	119	#endif
	120	};
	121
	122	struct btrfs_eb_write_context {
	123	struct writeback_control *wbc;
	124	struct extent_buffer *eb;
	125	/* Block group @eb resides in. Only used for zoned mode. */
	126	struct btrfs_block_group *zoned_bg;
	127	};
	128
	129	static inline unsigned long offset_in_eb_folio(const struct extent_buffer *eb,
	130	u64 start)
	131	{
	132	ASSERT(eb->folio_size);
	133	return start & (eb->folio_size - 1);
	134	}
	135
	136	/*
	137	* Get the correct offset inside the page of extent buffer.
	138	*
	139	* @eb: target extent buffer
	140	* @start: offset inside the extent buffer
	141	*
	142	* Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
	143	*/
	144	static inline size_t get_eb_offset_in_folio(const struct extent_buffer *eb,
	145	unsigned long offset)
	146	{
	147	/*
	148	* 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case
	149	* 1.1) One large folio covering the whole eb
	150	* The eb->start is aligned to folio size, thus adding it
	151	* won't cause any difference.
	152	* 1.2) Several page sized folios
	153	* The eb->start is aligned to folio (page) size, thus
	154	* adding it won't cause any difference.
	155	*
	156	* 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case
	157	* In this case there would only be one page sized folio, and there
	158	* may be several different extent buffers in the page/folio.
	159	* We need to add eb->start to properly access the offset inside
	160	* that eb.
	161	*/
	162	return offset_in_folio(eb->folios[0], offset + eb->start);
	163	}
	164
	165	static inline unsigned long get_eb_folio_index(const struct extent_buffer *eb,
	166	unsigned long offset)
	167	{
	168	/*
	169	* 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case
	170	* 1.1) One large folio covering the whole eb.
	171	* the folio_shift would be large enough to always make us
	172	* return 0 as index.
	173	* 1.2) Several page sized folios
	174	* The folio_shift would be PAGE_SHIFT, giving us the correct
	175	* index.
	176	*
	177	* 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case
	178	* The folio would only be page sized, and always give us 0 as index.
	179	*/
	180	return offset >> eb->folio_shift;
	181	}
	182
	183	/*
	184	* Structure to record how many bytes and which ranges are set/cleared
	185	*/
	186	struct extent_changeset {
	187	/* How many bytes are set/cleared in this operation */
	188	u64 bytes_changed;
	189
	190	/* Changed ranges */
	191	struct ulist range_changed;
	192	};
	193
	194	static inline void extent_changeset_init(struct extent_changeset *changeset)
	195	{
	196	changeset->bytes_changed = 0;
	197	ulist_init(&changeset->range_changed);
	198	}
	199
	200	static inline struct extent_changeset *extent_changeset_alloc(void)
	201	{
	202	struct extent_changeset *ret;
	203
	204	ret = kmalloc(sizeof(*ret), GFP_KERNEL);
	205	if (!ret)
	206	return NULL;
	207
	208	extent_changeset_init(ret);
	209	return ret;
	210	}
	211
	212	static inline void extent_changeset_prealloc(struct extent_changeset *changeset, gfp_t gfp_mask)
	213	{
	214	ulist_prealloc(&changeset->range_changed, gfp_mask);
	215	}
	216
	217	static inline void extent_changeset_release(struct extent_changeset *changeset)
	218	{
	219	if (!changeset)
	220	return;
	221	changeset->bytes_changed = 0;
	222	ulist_release(&changeset->range_changed);
	223	}
	224
	225	static inline void extent_changeset_free(struct extent_changeset *changeset)
	226	{
	227	if (!changeset)
	228	return;
	229	extent_changeset_release(changeset);
	230	kfree(changeset);
	231	}
	232
	233	bool try_release_extent_mapping(struct folio *folio, gfp_t mask);
	234	int try_release_extent_buffer(struct folio *folio);
	235
	236	int btrfs_read_folio(struct file file, struct folio folio);
	237	void extent_write_locked_range(struct inode inode, const struct folio locked_folio,
	238	u64 start, u64 end, struct writeback_control *wbc,
	239	bool pages_dirty);
	240	int btrfs_writepages(struct address_space mapping, struct writeback_control wbc);
	241	int btree_write_cache_pages(struct address_space *mapping,
	242	struct writeback_control *wbc);
	243	void btrfs_btree_wait_writeback_range(struct btrfs_fs_info *fs_info, u64 start, u64 end);
	244	void btrfs_readahead(struct readahead_control *rac);
	245	int set_folio_extent_mapped(struct folio *folio);
	246	void clear_folio_extent_mapped(struct folio *folio);
	247
	248	struct extent_buffer alloc_extent_buffer(struct btrfs_fs_info fs_info,
	249	u64 start, u64 owner_root, int level);
	250	struct extent_buffer alloc_dummy_extent_buffer(struct btrfs_fs_info fs_info,
	251	u64 start);
	252	struct extent_buffer btrfs_clone_extent_buffer(const struct extent_buffer src);
	253	struct extent_buffer find_extent_buffer(struct btrfs_fs_info fs_info,
	254	u64 start);
	255	void free_extent_buffer(struct extent_buffer *eb);
	256	void free_extent_buffer_stale(struct extent_buffer *eb);
	257	int read_extent_buffer_pages(struct extent_buffer *eb, int mirror_num,
	258	const struct btrfs_tree_parent_check *parent_check);
	259	int read_extent_buffer_pages_nowait(struct extent_buffer *eb, int mirror_num,
	260	const struct btrfs_tree_parent_check *parent_check);
	261
	262	static inline void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
	263	{
	264	wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
	265	TASK_UNINTERRUPTIBLE);
	266	}
	267
	268	void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
	269	u64 bytenr, u64 owner_root, u64 gen, int level);
	270	void btrfs_readahead_node_child(struct extent_buffer *node, int slot);
	271
	272	/* Note: this can be used in for loops without caching the value in a variable. */
	273	static inline int __pure num_extent_pages(const struct extent_buffer *eb)
	274	{
	275	/*
	276	* For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
	277	* sectorsize, it's just eb->len >> PAGE_SHIFT.
	278	*
	279	* For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
	280	* thus have to ensure we get at least one page.
	281	*/
	282	return (eb->len >> PAGE_SHIFT) ?: 1;
	283	}
	284
	285	/*
	286	* This can only be determined at runtime by checking eb::folios[0].
	287	*
	288	* As we can have either one large folio covering the whole eb
	289	* (either nodesize <= PAGE_SIZE, or high order folio), or multiple
	290	* single-paged folios.
	291	*
	292	* Note: this can be used in for loops without caching the value in a variable.
	293	*/
	294	static inline int __pure num_extent_folios(const struct extent_buffer *eb)
	295	{
	296	if (!eb->folios[0])
	297	return 0;
	298	if (folio_order(eb->folios[0]))
	299	return 1;
	300	return num_extent_pages(eb);
	301	}
	302
	303	static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
	304	{
	305	return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
	306	}
	307
	308	int memcmp_extent_buffer(const struct extent_buffer eb, const void ptrv,
	309	unsigned long start, unsigned long len);
	310	void read_extent_buffer(const struct extent_buffer eb, void dst,
	311	unsigned long start,
	312	unsigned long len);
	313	int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
	314	void __user *dst, unsigned long start,
	315	unsigned long len);
	316	void write_extent_buffer(const struct extent_buffer eb, const void src,
	317	unsigned long start, unsigned long len);
	318
	319	static inline void write_extent_buffer_chunk_tree_uuid(
	320	const struct extent_buffer eb, const void chunk_tree_uuid)
	321	{
	322	write_extent_buffer(eb, chunk_tree_uuid,
	323	offsetof(struct btrfs_header, chunk_tree_uuid),
	324	BTRFS_FSID_SIZE);
	325	}
	326
	327	static inline void write_extent_buffer_fsid(const struct extent_buffer *eb,
	328	const void *fsid)
	329	{
	330	write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
	331	BTRFS_FSID_SIZE);
	332	}
	333
	334	void copy_extent_buffer_full(const struct extent_buffer *dst,
	335	const struct extent_buffer *src);
	336	void copy_extent_buffer(const struct extent_buffer *dst,
	337	const struct extent_buffer *src,
	338	unsigned long dst_offset, unsigned long src_offset,
	339	unsigned long len);
	340	void memcpy_extent_buffer(const struct extent_buffer *dst,
	341	unsigned long dst_offset, unsigned long src_offset,
	342	unsigned long len);
	343	void memmove_extent_buffer(const struct extent_buffer *dst,
	344	unsigned long dst_offset, unsigned long src_offset,
	345	unsigned long len);
	346	void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
	347	unsigned long len);
	348	int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
	349	unsigned long pos);
	350	void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
	351	unsigned long pos, unsigned long len);
	352	void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
	353	unsigned long start, unsigned long pos,
	354	unsigned long len);
	355	void set_extent_buffer_dirty(struct extent_buffer *eb);
	356	void set_extent_buffer_uptodate(struct extent_buffer *eb);
	357	void clear_extent_buffer_uptodate(struct extent_buffer *eb);
	358	void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
	359	const struct folio *locked_folio,
	360	struct extent_state **cached,
	361	u32 bits_to_clear, unsigned long page_ops);
	362	int extent_invalidate_folio(struct extent_io_tree *tree,
	363	struct folio *folio, size_t offset);
	364	void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
	365	struct extent_buffer *buf);
	366
	367	int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array,
	368	bool nofail);
	369	int btrfs_alloc_folio_array(unsigned int nr_folios, struct folio **folio_array);
	370
	371	#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
	372	bool find_lock_delalloc_range(struct inode *inode,
	373	struct folio locked_folio, u64 start,
	374	u64 *end);
	375	#endif
	376	struct extent_buffer alloc_test_extent_buffer(struct btrfs_fs_info fs_info,
	377	u64 start);
	378
	379	#ifdef CONFIG_BTRFS_DEBUG
	380	void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
	381	#else
	382	#define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0)
	383	#endif
	384
	385	#endif