diff options
Diffstat (limited to 'fs/btrfs/extent_io.h')
| -rw-r--r-- | fs/btrfs/extent_io.h | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h new file mode 100644 index 0000000000..68368ba993 --- /dev/null +++ b/fs/btrfs/extent_io.h @@ -0,0 +1,313 @@ +/* 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, + EXTENT_BUFFER_NO_CHECK, + /* 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), +}; + +/* + * 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 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; + spinlock_t refs_lock; + atomic_t refs; + int read_mirror; + struct rcu_head rcu_head; + pid_t lock_owner; + /* >= 0 if eb belongs to a log tree, -1 otherwise */ + s8 log_index; + + struct rw_semaphore lock; + + struct page *pages[INLINE_EXTENT_BUFFER_PAGES]; +#ifdef CONFIG_BTRFS_DEBUG + struct list_head leak_list; +#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_page(const struct extent_buffer *eb, + unsigned long offset) +{ + /* + * For sectorsize == PAGE_SIZE case, eb->start will always be aligned + * to PAGE_SIZE, thus adding it won't cause any difference. + * + * For sectorsize < PAGE_SIZE, we must only read the data that belongs + * to the eb, thus we have to take the eb->start into consideration. + */ + return offset_in_page(offset + eb->start); +} + +static inline unsigned long get_eb_page_index(unsigned long offset) +{ + /* + * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough. + * + * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE, + * and have ensured that all tree blocks are contained in one page, + * thus we always get index == 0. + */ + return offset >> PAGE_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_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; +} + +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); + +#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 |