1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2000-2005 Silicon Graphics, Inc. 4 * All Rights Reserved. 5 */ 6 #ifndef __XFS_BUF_H__ 7 #define __XFS_BUF_H__ 8 9 #include <linux/list.h> 10 #include <linux/types.h> 11 #include <linux/spinlock.h> 12 #include <linux/mm.h> 13 #include <linux/fs.h> 14 #include <linux/dax.h> 15 #include <linux/uio.h> 16 #include <linux/list_lru.h> 17 18 extern struct kmem_cache *xfs_buf_cache; 19 20 /* 21 * Base types 22 */ 23 struct xfs_buf; 24 25 #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL)) 26 27 #define XBF_READ (1u << 0) /* buffer intended for reading from device */ 28 #define XBF_WRITE (1u << 1) /* buffer intended for writing to device */ 29 #define XBF_READ_AHEAD (1u << 2) /* asynchronous read-ahead */ 30 #define XBF_NO_IOACCT (1u << 3) /* bypass I/O accounting (non-LRU bufs) */ 31 #define XBF_ASYNC (1u << 4) /* initiator will not wait for completion */ 32 #define XBF_DONE (1u << 5) /* all pages in the buffer uptodate */ 33 #define XBF_STALE (1u << 6) /* buffer has been staled, do not find it */ 34 #define XBF_WRITE_FAIL (1u << 7) /* async writes have failed on this buffer */ 35 36 /* buffer type flags for write callbacks */ 37 #define _XBF_INODES (1u << 16)/* inode buffer */ 38 #define _XBF_DQUOTS (1u << 17)/* dquot buffer */ 39 #define _XBF_LOGRECOVERY (1u << 18)/* log recovery buffer */ 40 41 /* flags used only internally */ 42 #define _XBF_PAGES (1u << 20)/* backed by refcounted pages */ 43 #define _XBF_KMEM (1u << 21)/* backed by heap memory */ 44 #define _XBF_DELWRI_Q (1u << 22)/* buffer on a delwri queue */ 45 46 /* flags used only as arguments to access routines */ 47 /* 48 * Online fsck is scanning the buffer cache for live buffers. Do not warn 49 * about length mismatches during lookups and do not return stale buffers. 50 */ 51 #define XBF_LIVESCAN (1u << 28) 52 #define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */ 53 #define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */ 54 #define XBF_UNMAPPED (1u << 31)/* do not map the buffer */ 55 56 57 typedef unsigned int xfs_buf_flags_t; 58 59 #define XFS_BUF_FLAGS \ 60 { XBF_READ, "READ" }, \ 61 { XBF_WRITE, "WRITE" }, \ 62 { XBF_READ_AHEAD, "READ_AHEAD" }, \ 63 { XBF_NO_IOACCT, "NO_IOACCT" }, \ 64 { XBF_ASYNC, "ASYNC" }, \ 65 { XBF_DONE, "DONE" }, \ 66 { XBF_STALE, "STALE" }, \ 67 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \ 68 { _XBF_INODES, "INODES" }, \ 69 { _XBF_DQUOTS, "DQUOTS" }, \ 70 { _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \ 71 { _XBF_PAGES, "PAGES" }, \ 72 { _XBF_KMEM, "KMEM" }, \ 73 { _XBF_DELWRI_Q, "DELWRI_Q" }, \ 74 /* The following interface flags should never be set */ \ 75 { XBF_LIVESCAN, "LIVESCAN" }, \ 76 { XBF_INCORE, "INCORE" }, \ 77 { XBF_TRYLOCK, "TRYLOCK" }, \ 78 { XBF_UNMAPPED, "UNMAPPED" } 79 80 /* 81 * Internal state flags. 82 */ 83 #define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */ 84 #define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */ 85 86 struct xfs_buf_cache { 87 spinlock_t bc_lock; 88 struct rhashtable bc_hash; 89 }; 90 91 int xfs_buf_cache_init(struct xfs_buf_cache *bch); 92 void xfs_buf_cache_destroy(struct xfs_buf_cache *bch); 93 94 /* 95 * The xfs_buftarg contains 2 notions of "sector size" - 96 * 97 * 1) The metadata sector size, which is the minimum unit and 98 * alignment of IO which will be performed by metadata operations. 99 * 2) The device logical sector size 100 * 101 * The first is specified at mkfs time, and is stored on-disk in the 102 * superblock's sb_sectsize. 103 * 104 * The latter is derived from the underlying device, and controls direct IO 105 * alignment constraints. 106 */ 107 struct xfs_buftarg { 108 dev_t bt_dev; 109 struct file *bt_bdev_file; 110 struct block_device *bt_bdev; 111 struct dax_device *bt_daxdev; 112 struct file *bt_file; 113 u64 bt_dax_part_off; 114 struct xfs_mount *bt_mount; 115 unsigned int bt_meta_sectorsize; 116 size_t bt_meta_sectormask; 117 size_t bt_logical_sectorsize; 118 size_t bt_logical_sectormask; 119 120 /* LRU control structures */ 121 struct shrinker *bt_shrinker; 122 struct list_lru bt_lru; 123 124 struct percpu_counter bt_io_count; 125 struct ratelimit_state bt_ioerror_rl; 126 127 /* built-in cache, if we're not using the perag one */ 128 struct xfs_buf_cache bt_cache[]; 129 }; 130 131 #define XB_PAGES 2 132 133 struct xfs_buf_map { 134 xfs_daddr_t bm_bn; /* block number for I/O */ 135 int bm_len; /* size of I/O */ 136 unsigned int bm_flags; 137 }; 138 139 /* 140 * Online fsck is scanning the buffer cache for live buffers. Do not warn 141 * about length mismatches during lookups and do not return stale buffers. 142 */ 143 #define XBM_LIVESCAN (1U << 0) 144 145 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ 146 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; 147 148 struct xfs_buf_ops { 149 char *name; 150 union { 151 __be32 magic[2]; /* v4 and v5 on disk magic values */ 152 __be16 magic16[2]; /* v4 and v5 on disk magic values */ 153 }; 154 void (*verify_read)(struct xfs_buf *); 155 void (*verify_write)(struct xfs_buf *); 156 xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); 157 }; 158 159 struct xfs_buf { 160 /* 161 * first cacheline holds all the fields needed for an uncontended cache 162 * hit to be fully processed. The semaphore straddles the cacheline 163 * boundary, but the counter and lock sits on the first cacheline, 164 * which is the only bit that is touched if we hit the semaphore 165 * fast-path on locking. 166 */ 167 struct rhash_head b_rhash_head; /* pag buffer hash node */ 168 169 xfs_daddr_t b_rhash_key; /* buffer cache index */ 170 int b_length; /* size of buffer in BBs */ 171 atomic_t b_hold; /* reference count */ 172 atomic_t b_lru_ref; /* lru reclaim ref count */ 173 xfs_buf_flags_t b_flags; /* status flags */ 174 struct semaphore b_sema; /* semaphore for lockables */ 175 176 /* 177 * concurrent access to b_lru and b_lru_flags are protected by 178 * bt_lru_lock and not by b_sema 179 */ 180 struct list_head b_lru; /* lru list */ 181 spinlock_t b_lock; /* internal state lock */ 182 unsigned int b_state; /* internal state flags */ 183 int b_io_error; /* internal IO error state */ 184 wait_queue_head_t b_waiters; /* unpin waiters */ 185 struct list_head b_list; 186 struct xfs_perag *b_pag; /* contains rbtree root */ 187 struct xfs_mount *b_mount; 188 struct xfs_buftarg *b_target; /* buffer target (device) */ 189 void *b_addr; /* virtual address of buffer */ 190 struct work_struct b_ioend_work; 191 struct completion b_iowait; /* queue for I/O waiters */ 192 struct xfs_buf_log_item *b_log_item; 193 struct list_head b_li_list; /* Log items list head */ 194 struct xfs_trans *b_transp; 195 struct page **b_pages; /* array of page pointers */ 196 struct page *b_page_array[XB_PAGES]; /* inline pages */ 197 struct xfs_buf_map *b_maps; /* compound buffer map */ 198 struct xfs_buf_map __b_map; /* inline compound buffer map */ 199 int b_map_count; 200 atomic_t b_pin_count; /* pin count */ 201 atomic_t b_io_remaining; /* #outstanding I/O requests */ 202 unsigned int b_page_count; /* size of page array */ 203 unsigned int b_offset; /* page offset of b_addr, 204 only for _XBF_KMEM buffers */ 205 int b_error; /* error code on I/O */ 206 207 /* 208 * async write failure retry count. Initialised to zero on the first 209 * failure, then when it exceeds the maximum configured without a 210 * success the write is considered to be failed permanently and the 211 * iodone handler will take appropriate action. 212 * 213 * For retry timeouts, we record the jiffy of the first failure. This 214 * means that we can change the retry timeout for buffers already under 215 * I/O and thus avoid getting stuck in a retry loop with a long timeout. 216 * 217 * last_error is used to ensure that we are getting repeated errors, not 218 * different errors. e.g. a block device might change ENOSPC to EIO when 219 * a failure timeout occurs, so we want to re-initialise the error 220 * retry behaviour appropriately when that happens. 221 */ 222 int b_retries; 223 unsigned long b_first_retry_time; /* in jiffies */ 224 int b_last_error; 225 226 const struct xfs_buf_ops *b_ops; 227 struct rcu_head b_rcu; 228 }; 229 230 /* Finding and Reading Buffers */ 231 int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 232 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp); 233 int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 234 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, 235 const struct xfs_buf_ops *ops, xfs_failaddr_t fa); 236 void xfs_buf_readahead_map(struct xfs_buftarg *target, 237 struct xfs_buf_map *map, int nmaps, 238 const struct xfs_buf_ops *ops); 239 240 static inline int 241 xfs_buf_incore( 242 struct xfs_buftarg *target, 243 xfs_daddr_t blkno, 244 size_t numblks, 245 xfs_buf_flags_t flags, 246 struct xfs_buf **bpp) 247 { 248 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 249 250 return xfs_buf_get_map(target, &map, 1, XBF_INCORE | flags, bpp); 251 } 252 253 static inline int 254 xfs_buf_get( 255 struct xfs_buftarg *target, 256 xfs_daddr_t blkno, 257 size_t numblks, 258 struct xfs_buf **bpp) 259 { 260 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 261 262 return xfs_buf_get_map(target, &map, 1, 0, bpp); 263 } 264 265 static inline int 266 xfs_buf_read( 267 struct xfs_buftarg *target, 268 xfs_daddr_t blkno, 269 size_t numblks, 270 xfs_buf_flags_t flags, 271 struct xfs_buf **bpp, 272 const struct xfs_buf_ops *ops) 273 { 274 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 275 276 return xfs_buf_read_map(target, &map, 1, flags, bpp, ops, 277 __builtin_return_address(0)); 278 } 279 280 static inline void 281 xfs_buf_readahead( 282 struct xfs_buftarg *target, 283 xfs_daddr_t blkno, 284 size_t numblks, 285 const struct xfs_buf_ops *ops) 286 { 287 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 288 return xfs_buf_readahead_map(target, &map, 1, ops); 289 } 290 291 int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, 292 xfs_buf_flags_t flags, struct xfs_buf **bpp); 293 int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, 294 size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp, 295 const struct xfs_buf_ops *ops); 296 int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags); 297 void xfs_buf_hold(struct xfs_buf *bp); 298 299 /* Releasing Buffers */ 300 extern void xfs_buf_rele(struct xfs_buf *); 301 302 /* Locking and Unlocking Buffers */ 303 extern int xfs_buf_trylock(struct xfs_buf *); 304 extern void xfs_buf_lock(struct xfs_buf *); 305 extern void xfs_buf_unlock(struct xfs_buf *); 306 #define xfs_buf_islocked(bp) \ 307 ((bp)->b_sema.count <= 0) 308 309 static inline void xfs_buf_relse(struct xfs_buf *bp) 310 { 311 xfs_buf_unlock(bp); 312 xfs_buf_rele(bp); 313 } 314 315 /* Buffer Read and Write Routines */ 316 extern int xfs_bwrite(struct xfs_buf *bp); 317 318 extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, 319 xfs_failaddr_t failaddr); 320 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) 321 extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa); 322 void xfs_buf_ioend_fail(struct xfs_buf *); 323 void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize); 324 void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa); 325 #define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address) 326 327 /* Buffer Utility Routines */ 328 extern void *xfs_buf_offset(struct xfs_buf *, size_t); 329 extern void xfs_buf_stale(struct xfs_buf *bp); 330 331 /* Delayed Write Buffer Routines */ 332 extern void xfs_buf_delwri_cancel(struct list_head *); 333 extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); 334 void xfs_buf_delwri_queue_here(struct xfs_buf *bp, struct list_head *bl); 335 extern int xfs_buf_delwri_submit(struct list_head *); 336 extern int xfs_buf_delwri_submit_nowait(struct list_head *); 337 extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); 338 339 static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) 340 { 341 return bp->b_maps[0].bm_bn; 342 } 343 344 void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); 345 346 /* 347 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer 348 * up with a reference count of 0 so it will be tossed from the cache when 349 * released. 350 */ 351 static inline void xfs_buf_oneshot(struct xfs_buf *bp) 352 { 353 if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1) 354 return; 355 atomic_set(&bp->b_lru_ref, 0); 356 } 357 358 static inline int xfs_buf_ispinned(struct xfs_buf *bp) 359 { 360 return atomic_read(&bp->b_pin_count); 361 } 362 363 static inline int 364 xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 365 { 366 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), 367 cksum_offset); 368 } 369 370 static inline void 371 xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 372 { 373 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), 374 cksum_offset); 375 } 376 377 /* 378 * Handling of buftargs. 379 */ 380 struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp, 381 struct file *bdev_file); 382 extern void xfs_free_buftarg(struct xfs_buftarg *); 383 extern void xfs_buftarg_wait(struct xfs_buftarg *); 384 extern void xfs_buftarg_drain(struct xfs_buftarg *); 385 extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int); 386 387 #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) 388 #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) 389 390 int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); 391 bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic); 392 bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic); 393 394 /* for xfs_buf_mem.c only: */ 395 int xfs_init_buftarg(struct xfs_buftarg *btp, size_t logical_sectorsize, 396 const char *descr); 397 void xfs_destroy_buftarg(struct xfs_buftarg *btp); 398 399 #endif /* __XFS_BUF_H__ */ 400