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