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_MAX ((xfs_daddr_t) S64_MAX) 26 #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL)) 27 28 #define XBF_READ (1u << 0) /* buffer intended for reading from device */ 29 #define XBF_WRITE (1u << 1) /* buffer intended for writing to device */ 30 #define XBF_READ_AHEAD (1u << 2) /* asynchronous read-ahead */ 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_LOGRECOVERY (1u << 18)/* log recovery buffer */ 38 39 /* flags used only internally */ 40 #define _XBF_KMEM (1u << 21)/* backed by heap memory */ 41 #define _XBF_DELWRI_Q (1u << 22)/* buffer on a delwri queue */ 42 43 /* flags used only as arguments to access routines */ 44 /* 45 * Online fsck is scanning the buffer cache for live buffers. Do not warn 46 * about length mismatches during lookups and do not return stale buffers. 47 */ 48 #define XBF_LIVESCAN (1u << 28) 49 #define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */ 50 #define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */ 51 52 53 typedef unsigned int xfs_buf_flags_t; 54 55 #define XFS_BUF_FLAGS \ 56 { XBF_READ, "READ" }, \ 57 { XBF_WRITE, "WRITE" }, \ 58 { XBF_READ_AHEAD, "READ_AHEAD" }, \ 59 { XBF_ASYNC, "ASYNC" }, \ 60 { XBF_DONE, "DONE" }, \ 61 { XBF_STALE, "STALE" }, \ 62 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \ 63 { _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \ 64 { _XBF_KMEM, "KMEM" }, \ 65 { _XBF_DELWRI_Q, "DELWRI_Q" }, \ 66 /* The following interface flags should never be set */ \ 67 { XBF_LIVESCAN, "LIVESCAN" }, \ 68 { XBF_INCORE, "INCORE" }, \ 69 { XBF_TRYLOCK, "TRYLOCK" } 70 71 /* 72 * Internal state flags. 73 */ 74 #define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */ 75 76 struct xfs_buf_cache { 77 struct rhashtable bc_hash; 78 }; 79 80 int xfs_buf_cache_init(struct xfs_buf_cache *bch); 81 void xfs_buf_cache_destroy(struct xfs_buf_cache *bch); 82 83 /* 84 * The xfs_buftarg contains 2 notions of "sector size" - 85 * 86 * 1) The metadata sector size, which is the minimum unit and 87 * alignment of IO which will be performed by metadata operations. 88 * 2) The device logical sector size 89 * 90 * The first is specified at mkfs time, and is stored on-disk in the 91 * superblock's sb_sectsize. 92 * 93 * The latter is derived from the underlying device, and controls direct IO 94 * alignment constraints. 95 */ 96 struct xfs_buftarg { 97 dev_t bt_dev; 98 struct block_device *bt_bdev; 99 struct dax_device *bt_daxdev; 100 struct file *bt_file; 101 u64 bt_dax_part_off; 102 struct xfs_mount *bt_mount; 103 unsigned int bt_meta_sectorsize; 104 size_t bt_meta_sectormask; 105 size_t bt_logical_sectorsize; 106 size_t bt_logical_sectormask; 107 xfs_daddr_t bt_nr_sectors; 108 109 /* LRU control structures */ 110 struct shrinker *bt_shrinker; 111 struct list_lru bt_lru; 112 113 struct percpu_counter bt_readahead_count; 114 struct ratelimit_state bt_ioerror_rl; 115 116 /* Hardware atomic write unit values, bytes */ 117 unsigned int bt_awu_min; 118 unsigned int bt_awu_max; 119 120 /* built-in cache, if we're not using the perag one */ 121 struct xfs_buf_cache bt_cache[]; 122 }; 123 124 struct xfs_buf_map { 125 xfs_daddr_t bm_bn; /* block number for I/O */ 126 int bm_len; /* size of I/O */ 127 unsigned int bm_flags; 128 }; 129 130 /* 131 * Online fsck is scanning the buffer cache for live buffers. Do not warn 132 * about length mismatches during lookups and do not return stale buffers. 133 */ 134 #define XBM_LIVESCAN (1U << 0) 135 136 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ 137 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; 138 139 struct xfs_buf_ops { 140 char *name; 141 union { 142 __be32 magic[2]; /* v4 and v5 on disk magic values */ 143 __be16 magic16[2]; /* v4 and v5 on disk magic values */ 144 }; 145 void (*verify_read)(struct xfs_buf *); 146 void (*verify_write)(struct xfs_buf *); 147 xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); 148 }; 149 150 struct xfs_buf { 151 /* 152 * first cacheline holds all the fields needed for an uncontended cache 153 * hit to be fully processed. The semaphore straddles the cacheline 154 * boundary, but the counter and lock sits on the first cacheline, 155 * which is the only bit that is touched if we hit the semaphore 156 * fast-path on locking. 157 */ 158 struct rhash_head b_rhash_head; /* pag buffer hash node */ 159 160 xfs_daddr_t b_rhash_key; /* buffer cache index */ 161 int b_length; /* size of buffer in BBs */ 162 unsigned int b_hold; /* reference count */ 163 atomic_t b_lru_ref; /* lru reclaim ref count */ 164 xfs_buf_flags_t b_flags; /* status flags */ 165 struct semaphore b_sema; /* semaphore for lockables */ 166 167 /* 168 * concurrent access to b_lru and b_lru_flags are protected by 169 * bt_lru_lock and not by b_sema 170 */ 171 struct list_head b_lru; /* lru list */ 172 spinlock_t b_lock; /* internal state lock */ 173 unsigned int b_state; /* internal state flags */ 174 wait_queue_head_t b_waiters; /* unpin waiters */ 175 struct list_head b_list; 176 struct xfs_perag *b_pag; 177 struct xfs_mount *b_mount; 178 struct xfs_buftarg *b_target; /* buffer target (device) */ 179 void *b_addr; /* virtual address of buffer */ 180 struct work_struct b_ioend_work; 181 struct completion b_iowait; /* queue for I/O waiters */ 182 struct xfs_buf_log_item *b_log_item; 183 struct list_head b_li_list; /* Log items list head */ 184 struct xfs_trans *b_transp; 185 struct xfs_buf_map *b_maps; /* compound buffer map */ 186 struct xfs_buf_map __b_map; /* inline compound buffer map */ 187 int b_map_count; 188 atomic_t b_pin_count; /* pin count */ 189 int b_error; /* error code on I/O */ 190 void (*b_iodone)(struct xfs_buf *bp); 191 192 /* 193 * async write failure retry count. Initialised to zero on the first 194 * failure, then when it exceeds the maximum configured without a 195 * success the write is considered to be failed permanently and the 196 * iodone handler will take appropriate action. 197 * 198 * For retry timeouts, we record the jiffy of the first failure. This 199 * means that we can change the retry timeout for buffers already under 200 * I/O and thus avoid getting stuck in a retry loop with a long timeout. 201 * 202 * last_error is used to ensure that we are getting repeated errors, not 203 * different errors. e.g. a block device might change ENOSPC to EIO when 204 * a failure timeout occurs, so we want to re-initialise the error 205 * retry behaviour appropriately when that happens. 206 */ 207 int b_retries; 208 unsigned long b_first_retry_time; /* in jiffies */ 209 int b_last_error; 210 211 const struct xfs_buf_ops *b_ops; 212 struct rcu_head b_rcu; 213 }; 214 215 /* Finding and Reading Buffers */ 216 int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 217 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp); 218 int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 219 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, 220 const struct xfs_buf_ops *ops, xfs_failaddr_t fa); 221 void xfs_buf_readahead_map(struct xfs_buftarg *target, 222 struct xfs_buf_map *map, int nmaps, 223 const struct xfs_buf_ops *ops); 224 225 static inline int 226 xfs_buf_incore( 227 struct xfs_buftarg *target, 228 xfs_daddr_t blkno, 229 size_t numblks, 230 xfs_buf_flags_t flags, 231 struct xfs_buf **bpp) 232 { 233 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 234 235 return xfs_buf_get_map(target, &map, 1, XBF_INCORE | flags, bpp); 236 } 237 238 static inline int 239 xfs_buf_get( 240 struct xfs_buftarg *target, 241 xfs_daddr_t blkno, 242 size_t numblks, 243 struct xfs_buf **bpp) 244 { 245 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 246 247 return xfs_buf_get_map(target, &map, 1, 0, bpp); 248 } 249 250 static inline int 251 xfs_buf_read( 252 struct xfs_buftarg *target, 253 xfs_daddr_t blkno, 254 size_t numblks, 255 xfs_buf_flags_t flags, 256 struct xfs_buf **bpp, 257 const struct xfs_buf_ops *ops) 258 { 259 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 260 261 return xfs_buf_read_map(target, &map, 1, flags, bpp, ops, 262 __builtin_return_address(0)); 263 } 264 265 static inline void 266 xfs_buf_readahead( 267 struct xfs_buftarg *target, 268 xfs_daddr_t blkno, 269 size_t numblks, 270 const struct xfs_buf_ops *ops) 271 { 272 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 273 return xfs_buf_readahead_map(target, &map, 1, ops); 274 } 275 276 int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, 277 struct xfs_buf **bpp); 278 int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, 279 size_t numblks, struct xfs_buf **bpp, 280 const struct xfs_buf_ops *ops); 281 int _xfs_buf_read(struct xfs_buf *bp); 282 void xfs_buf_hold(struct xfs_buf *bp); 283 284 /* Releasing Buffers */ 285 extern void xfs_buf_rele(struct xfs_buf *); 286 287 /* Locking and Unlocking Buffers */ 288 extern int xfs_buf_trylock(struct xfs_buf *); 289 extern void xfs_buf_lock(struct xfs_buf *); 290 extern void xfs_buf_unlock(struct xfs_buf *); 291 #define xfs_buf_islocked(bp) \ 292 ((bp)->b_sema.count <= 0) 293 294 static inline void xfs_buf_relse(struct xfs_buf *bp) 295 { 296 xfs_buf_unlock(bp); 297 xfs_buf_rele(bp); 298 } 299 300 /* Buffer Read and Write Routines */ 301 extern int xfs_bwrite(struct xfs_buf *bp); 302 303 extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, 304 xfs_failaddr_t failaddr); 305 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) 306 extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa); 307 void xfs_buf_ioend_fail(struct xfs_buf *); 308 void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa); 309 #define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address) 310 311 /* Buffer Utility Routines */ 312 static inline void *xfs_buf_offset(struct xfs_buf *bp, size_t offset) 313 { 314 return bp->b_addr + offset; 315 } 316 317 static inline void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize) 318 { 319 memset(bp->b_addr + boff, 0, bsize); 320 } 321 322 extern void xfs_buf_stale(struct xfs_buf *bp); 323 324 /* Delayed Write Buffer Routines */ 325 extern void xfs_buf_delwri_cancel(struct list_head *); 326 extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); 327 void xfs_buf_delwri_queue_here(struct xfs_buf *bp, struct list_head *bl); 328 extern int xfs_buf_delwri_submit(struct list_head *); 329 extern int xfs_buf_delwri_submit_nowait(struct list_head *); 330 331 static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) 332 { 333 return bp->b_maps[0].bm_bn; 334 } 335 336 void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); 337 338 /* 339 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer 340 * up with a reference count of 0 so it will be tossed from the cache when 341 * released. 342 */ 343 static inline void xfs_buf_oneshot(struct xfs_buf *bp) 344 { 345 if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1) 346 return; 347 atomic_set(&bp->b_lru_ref, 0); 348 } 349 350 static inline int xfs_buf_ispinned(struct xfs_buf *bp) 351 { 352 return atomic_read(&bp->b_pin_count); 353 } 354 355 static inline int 356 xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 357 { 358 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), 359 cksum_offset); 360 } 361 362 static inline void 363 xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 364 { 365 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), 366 cksum_offset); 367 } 368 369 /* 370 * Handling of buftargs. 371 */ 372 struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp, 373 struct file *bdev_file); 374 extern void xfs_free_buftarg(struct xfs_buftarg *); 375 extern void xfs_buftarg_wait(struct xfs_buftarg *); 376 extern void xfs_buftarg_drain(struct xfs_buftarg *); 377 int xfs_configure_buftarg(struct xfs_buftarg *btp, unsigned int sectorsize, 378 xfs_fsblock_t nr_blocks); 379 380 #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) 381 382 int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); 383 bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic); 384 bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic); 385 386 /* for xfs_buf_mem.c only: */ 387 int xfs_init_buftarg(struct xfs_buftarg *btp, size_t logical_sectorsize, 388 const char *descr); 389 void xfs_destroy_buftarg(struct xfs_buftarg *btp); 390 391 #endif /* __XFS_BUF_H__ */ 392