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_ASYNC (1u << 4) /* initiator will not wait for completion */ 31 #define XBF_DONE (1u << 5) /* all pages in the buffer uptodate */ 32 #define XBF_STALE (1u << 6) /* buffer has been staled, do not find it */ 33 #define XBF_WRITE_FAIL (1u << 7) /* async writes have failed on this buffer */ 34 35 /* buffer type flags for write callbacks */ 36 #define _XBF_LOGRECOVERY (1u << 18)/* log recovery buffer */ 37 38 /* flags used only internally */ 39 #define _XBF_KMEM (1u << 21)/* backed by heap memory */ 40 #define _XBF_DELWRI_Q (1u << 22)/* buffer on a delwri queue */ 41 42 /* flags used only as arguments to access routines */ 43 /* 44 * Online fsck is scanning the buffer cache for live buffers. Do not warn 45 * about length mismatches during lookups and do not return stale buffers. 46 */ 47 #define XBF_LIVESCAN (1u << 28) 48 #define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */ 49 #define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */ 50 51 52 typedef unsigned int xfs_buf_flags_t; 53 54 #define XFS_BUF_FLAGS \ 55 { XBF_READ, "READ" }, \ 56 { XBF_WRITE, "WRITE" }, \ 57 { XBF_READ_AHEAD, "READ_AHEAD" }, \ 58 { XBF_ASYNC, "ASYNC" }, \ 59 { XBF_DONE, "DONE" }, \ 60 { XBF_STALE, "STALE" }, \ 61 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \ 62 { _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \ 63 { _XBF_KMEM, "KMEM" }, \ 64 { _XBF_DELWRI_Q, "DELWRI_Q" }, \ 65 /* The following interface flags should never be set */ \ 66 { XBF_LIVESCAN, "LIVESCAN" }, \ 67 { XBF_INCORE, "INCORE" }, \ 68 { XBF_TRYLOCK, "TRYLOCK" } 69 70 /* 71 * Internal state flags. 72 */ 73 #define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */ 74 75 struct xfs_buf_cache { 76 struct rhashtable bc_hash; 77 }; 78 79 int xfs_buf_cache_init(struct xfs_buf_cache *bch); 80 void xfs_buf_cache_destroy(struct xfs_buf_cache *bch); 81 82 /* 83 * The xfs_buftarg contains 2 notions of "sector size" - 84 * 85 * 1) The metadata sector size, which is the minimum unit and 86 * alignment of IO which will be performed by metadata operations. 87 * 2) The device logical sector size 88 * 89 * The first is specified at mkfs time, and is stored on-disk in the 90 * superblock's sb_sectsize. 91 * 92 * The latter is derived from the underlying device, and controls direct IO 93 * alignment constraints. 94 */ 95 struct xfs_buftarg { 96 dev_t bt_dev; 97 struct file *bt_bdev_file; 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; 107 108 /* LRU control structures */ 109 struct shrinker *bt_shrinker; 110 struct list_lru bt_lru; 111 112 struct percpu_counter bt_readahead_count; 113 struct ratelimit_state bt_ioerror_rl; 114 115 /* Atomic write unit values */ 116 unsigned int bt_bdev_awu_min; 117 unsigned int bt_bdev_awu_max; 118 119 /* built-in cache, if we're not using the perag one */ 120 struct xfs_buf_cache bt_cache[]; 121 }; 122 123 struct xfs_buf_map { 124 xfs_daddr_t bm_bn; /* block number for I/O */ 125 int bm_len; /* size of I/O */ 126 unsigned int bm_flags; 127 }; 128 129 /* 130 * Online fsck is scanning the buffer cache for live buffers. Do not warn 131 * about length mismatches during lookups and do not return stale buffers. 132 */ 133 #define XBM_LIVESCAN (1U << 0) 134 135 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ 136 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; 137 138 struct xfs_buf_ops { 139 char *name; 140 union { 141 __be32 magic[2]; /* v4 and v5 on disk magic values */ 142 __be16 magic16[2]; /* v4 and v5 on disk magic values */ 143 }; 144 void (*verify_read)(struct xfs_buf *); 145 void (*verify_write)(struct xfs_buf *); 146 xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); 147 }; 148 149 struct xfs_buf { 150 /* 151 * first cacheline holds all the fields needed for an uncontended cache 152 * hit to be fully processed. The semaphore straddles the cacheline 153 * boundary, but the counter and lock sits on the first cacheline, 154 * which is the only bit that is touched if we hit the semaphore 155 * fast-path on locking. 156 */ 157 struct rhash_head b_rhash_head; /* pag buffer hash node */ 158 159 xfs_daddr_t b_rhash_key; /* buffer cache index */ 160 int b_length; /* size of buffer in BBs */ 161 unsigned int b_hold; /* reference count */ 162 atomic_t b_lru_ref; /* lru reclaim ref count */ 163 xfs_buf_flags_t b_flags; /* status flags */ 164 struct semaphore b_sema; /* semaphore for lockables */ 165 166 /* 167 * concurrent access to b_lru and b_lru_flags are protected by 168 * bt_lru_lock and not by b_sema 169 */ 170 struct list_head b_lru; /* lru list */ 171 spinlock_t b_lock; /* internal state lock */ 172 unsigned int b_state; /* internal state flags */ 173 wait_queue_head_t b_waiters; /* unpin waiters */ 174 struct list_head b_list; 175 struct xfs_perag *b_pag; 176 struct xfs_mount *b_mount; 177 struct xfs_buftarg *b_target; /* buffer target (device) */ 178 void *b_addr; /* virtual address of buffer */ 179 struct work_struct b_ioend_work; 180 struct completion b_iowait; /* queue for I/O waiters */ 181 struct xfs_buf_log_item *b_log_item; 182 struct list_head b_li_list; /* Log items list head */ 183 struct xfs_trans *b_transp; 184 struct xfs_buf_map *b_maps; /* compound buffer map */ 185 struct xfs_buf_map __b_map; /* inline compound buffer map */ 186 int b_map_count; 187 atomic_t b_pin_count; /* pin count */ 188 int b_error; /* error code on I/O */ 189 void (*b_iodone)(struct xfs_buf *bp); 190 191 /* 192 * async write failure retry count. Initialised to zero on the first 193 * failure, then when it exceeds the maximum configured without a 194 * success the write is considered to be failed permanently and the 195 * iodone handler will take appropriate action. 196 * 197 * For retry timeouts, we record the jiffy of the first failure. This 198 * means that we can change the retry timeout for buffers already under 199 * I/O and thus avoid getting stuck in a retry loop with a long timeout. 200 * 201 * last_error is used to ensure that we are getting repeated errors, not 202 * different errors. e.g. a block device might change ENOSPC to EIO when 203 * a failure timeout occurs, so we want to re-initialise the error 204 * retry behaviour appropriately when that happens. 205 */ 206 int b_retries; 207 unsigned long b_first_retry_time; /* in jiffies */ 208 int b_last_error; 209 210 const struct xfs_buf_ops *b_ops; 211 struct rcu_head b_rcu; 212 }; 213 214 /* Finding and Reading Buffers */ 215 int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 216 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp); 217 int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 218 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, 219 const struct xfs_buf_ops *ops, xfs_failaddr_t fa); 220 void xfs_buf_readahead_map(struct xfs_buftarg *target, 221 struct xfs_buf_map *map, int nmaps, 222 const struct xfs_buf_ops *ops); 223 224 static inline int 225 xfs_buf_incore( 226 struct xfs_buftarg *target, 227 xfs_daddr_t blkno, 228 size_t numblks, 229 xfs_buf_flags_t flags, 230 struct xfs_buf **bpp) 231 { 232 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 233 234 return xfs_buf_get_map(target, &map, 1, XBF_INCORE | flags, bpp); 235 } 236 237 static inline int 238 xfs_buf_get( 239 struct xfs_buftarg *target, 240 xfs_daddr_t blkno, 241 size_t numblks, 242 struct xfs_buf **bpp) 243 { 244 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 245 246 return xfs_buf_get_map(target, &map, 1, 0, bpp); 247 } 248 249 static inline int 250 xfs_buf_read( 251 struct xfs_buftarg *target, 252 xfs_daddr_t blkno, 253 size_t numblks, 254 xfs_buf_flags_t flags, 255 struct xfs_buf **bpp, 256 const struct xfs_buf_ops *ops) 257 { 258 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 259 260 return xfs_buf_read_map(target, &map, 1, flags, bpp, ops, 261 __builtin_return_address(0)); 262 } 263 264 static inline void 265 xfs_buf_readahead( 266 struct xfs_buftarg *target, 267 xfs_daddr_t blkno, 268 size_t numblks, 269 const struct xfs_buf_ops *ops) 270 { 271 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 272 return xfs_buf_readahead_map(target, &map, 1, ops); 273 } 274 275 int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, 276 struct xfs_buf **bpp); 277 int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, 278 size_t numblks, struct xfs_buf **bpp, 279 const struct xfs_buf_ops *ops); 280 int _xfs_buf_read(struct xfs_buf *bp); 281 void xfs_buf_hold(struct xfs_buf *bp); 282 283 /* Releasing Buffers */ 284 extern void xfs_buf_rele(struct xfs_buf *); 285 286 /* Locking and Unlocking Buffers */ 287 extern int xfs_buf_trylock(struct xfs_buf *); 288 extern void xfs_buf_lock(struct xfs_buf *); 289 extern void xfs_buf_unlock(struct xfs_buf *); 290 #define xfs_buf_islocked(bp) \ 291 ((bp)->b_sema.count <= 0) 292 293 static inline void xfs_buf_relse(struct xfs_buf *bp) 294 { 295 xfs_buf_unlock(bp); 296 xfs_buf_rele(bp); 297 } 298 299 /* Buffer Read and Write Routines */ 300 extern int xfs_bwrite(struct xfs_buf *bp); 301 302 extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, 303 xfs_failaddr_t failaddr); 304 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) 305 extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa); 306 void xfs_buf_ioend_fail(struct xfs_buf *); 307 void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa); 308 #define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address) 309 310 /* Buffer Utility Routines */ 311 static inline void *xfs_buf_offset(struct xfs_buf *bp, size_t offset) 312 { 313 return bp->b_addr + offset; 314 } 315 316 static inline void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize) 317 { 318 memset(bp->b_addr + boff, 0, bsize); 319 } 320 321 extern void xfs_buf_stale(struct xfs_buf *bp); 322 323 /* Delayed Write Buffer Routines */ 324 extern void xfs_buf_delwri_cancel(struct list_head *); 325 extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); 326 void xfs_buf_delwri_queue_here(struct xfs_buf *bp, struct list_head *bl); 327 extern int xfs_buf_delwri_submit(struct list_head *); 328 extern int xfs_buf_delwri_submit_nowait(struct list_head *); 329 extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, 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 extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int); 378 379 #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) 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