fs/btrfs/extent_io.h

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