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 /* Atomic write unit values */ 128 unsigned int bt_bdev_awu_min; 129 unsigned int bt_bdev_awu_max; 130 131 /* built-in cache, if we're not using the perag one */ 132 struct xfs_buf_cache bt_cache[]; 133 }; 134 135 #define XB_PAGES 2 136 137 struct xfs_buf_map { 138 xfs_daddr_t bm_bn; /* block number for I/O */ 139 int bm_len; /* size of I/O */ 140 unsigned int bm_flags; 141 }; 142 143 /* 144 * Online fsck is scanning the buffer cache for live buffers. Do not warn 145 * about length mismatches during lookups and do not return stale buffers. 146 */ 147 #define XBM_LIVESCAN (1U << 0) 148 149 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ 150 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; 151 152 struct xfs_buf_ops { 153 char *name; 154 union { 155 __be32 magic[2]; /* v4 and v5 on disk magic values */ 156 __be16 magic16[2]; /* v4 and v5 on disk magic values */ 157 }; 158 void (*verify_read)(struct xfs_buf *); 159 void (*verify_write)(struct xfs_buf *); 160 xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); 161 }; 162 163 struct xfs_buf { 164 /* 165 * first cacheline holds all the fields needed for an uncontended cache 166 * hit to be fully processed. The semaphore straddles the cacheline 167 * boundary, but the counter and lock sits on the first cacheline, 168 * which is the only bit that is touched if we hit the semaphore 169 * fast-path on locking. 170 */ 171 struct rhash_head b_rhash_head; /* pag buffer hash node */ 172 173 xfs_daddr_t b_rhash_key; /* buffer cache index */ 174 int b_length; /* size of buffer in BBs */ 175 atomic_t b_hold; /* reference count */ 176 atomic_t b_lru_ref; /* lru reclaim ref count */ 177 xfs_buf_flags_t b_flags; /* status flags */ 178 struct semaphore b_sema; /* semaphore for lockables */ 179 180 /* 181 * concurrent access to b_lru and b_lru_flags are protected by 182 * bt_lru_lock and not by b_sema 183 */ 184 struct list_head b_lru; /* lru list */ 185 spinlock_t b_lock; /* internal state lock */ 186 unsigned int b_state; /* internal state flags */ 187 int b_io_error; /* internal IO error state */ 188 wait_queue_head_t b_waiters; /* unpin waiters */ 189 struct list_head b_list; 190 struct xfs_perag *b_pag; /* contains rbtree root */ 191 struct xfs_mount *b_mount; 192 struct xfs_buftarg *b_target; /* buffer target (device) */ 193 void *b_addr; /* virtual address of buffer */ 194 struct work_struct b_ioend_work; 195 struct completion b_iowait; /* queue for I/O waiters */ 196 struct xfs_buf_log_item *b_log_item; 197 struct list_head b_li_list; /* Log items list head */ 198 struct xfs_trans *b_transp; 199 struct page **b_pages; /* array of page pointers */ 200 struct page *b_page_array[XB_PAGES]; /* inline pages */ 201 struct xfs_buf_map *b_maps; /* compound buffer map */ 202 struct xfs_buf_map __b_map; /* inline compound buffer map */ 203 int b_map_count; 204 atomic_t b_pin_count; /* pin count */ 205 atomic_t b_io_remaining; /* #outstanding I/O requests */ 206 unsigned int b_page_count; /* size of page array */ 207 unsigned int b_offset; /* page offset of b_addr, 208 only for _XBF_KMEM buffers */ 209 int b_error; /* error code on I/O */ 210 211 /* 212 * async write failure retry count. Initialised to zero on the first 213 * failure, then when it exceeds the maximum configured without a 214 * success the write is considered to be failed permanently and the 215 * iodone handler will take appropriate action. 216 * 217 * For retry timeouts, we record the jiffy of the first failure. This 218 * means that we can change the retry timeout for buffers already under 219 * I/O and thus avoid getting stuck in a retry loop with a long timeout. 220 * 221 * last_error is used to ensure that we are getting repeated errors, not 222 * different errors. e.g. a block device might change ENOSPC to EIO when 223 * a failure timeout occurs, so we want to re-initialise the error 224 * retry behaviour appropriately when that happens. 225 */ 226 int b_retries; 227 unsigned long b_first_retry_time; /* in jiffies */ 228 int b_last_error; 229 230 const struct xfs_buf_ops *b_ops; 231 struct rcu_head b_rcu; 232 }; 233 234 /* Finding and Reading Buffers */ 235 int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 236 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp); 237 int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 238 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, 239 const struct xfs_buf_ops *ops, xfs_failaddr_t fa); 240 void xfs_buf_readahead_map(struct xfs_buftarg *target, 241 struct xfs_buf_map *map, int nmaps, 242 const struct xfs_buf_ops *ops); 243 244 static inline int 245 xfs_buf_incore( 246 struct xfs_buftarg *target, 247 xfs_daddr_t blkno, 248 size_t numblks, 249 xfs_buf_flags_t flags, 250 struct xfs_buf **bpp) 251 { 252 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 253 254 return xfs_buf_get_map(target, &map, 1, XBF_INCORE | flags, bpp); 255 } 256 257 static inline int 258 xfs_buf_get( 259 struct xfs_buftarg *target, 260 xfs_daddr_t blkno, 261 size_t numblks, 262 struct xfs_buf **bpp) 263 { 264 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 265 266 return xfs_buf_get_map(target, &map, 1, 0, bpp); 267 } 268 269 static inline int 270 xfs_buf_read( 271 struct xfs_buftarg *target, 272 xfs_daddr_t blkno, 273 size_t numblks, 274 xfs_buf_flags_t flags, 275 struct xfs_buf **bpp, 276 const struct xfs_buf_ops *ops) 277 { 278 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 279 280 return xfs_buf_read_map(target, &map, 1, flags, bpp, ops, 281 __builtin_return_address(0)); 282 } 283 284 static inline void 285 xfs_buf_readahead( 286 struct xfs_buftarg *target, 287 xfs_daddr_t blkno, 288 size_t numblks, 289 const struct xfs_buf_ops *ops) 290 { 291 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 292 return xfs_buf_readahead_map(target, &map, 1, ops); 293 } 294 295 int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, 296 xfs_buf_flags_t flags, struct xfs_buf **bpp); 297 int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, 298 size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp, 299 const struct xfs_buf_ops *ops); 300 int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags); 301 void xfs_buf_hold(struct xfs_buf *bp); 302 303 /* Releasing Buffers */ 304 extern void xfs_buf_rele(struct xfs_buf *); 305 306 /* Locking and Unlocking Buffers */ 307 extern int xfs_buf_trylock(struct xfs_buf *); 308 extern void xfs_buf_lock(struct xfs_buf *); 309 extern void xfs_buf_unlock(struct xfs_buf *); 310 #define xfs_buf_islocked(bp) \ 311 ((bp)->b_sema.count <= 0) 312 313 static inline void xfs_buf_relse(struct xfs_buf *bp) 314 { 315 xfs_buf_unlock(bp); 316 xfs_buf_rele(bp); 317 } 318 319 /* Buffer Read and Write Routines */ 320 extern int xfs_bwrite(struct xfs_buf *bp); 321 322 extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, 323 xfs_failaddr_t failaddr); 324 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) 325 extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa); 326 void xfs_buf_ioend_fail(struct xfs_buf *); 327 void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize); 328 void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa); 329 #define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address) 330 331 /* Buffer Utility Routines */ 332 extern void *xfs_buf_offset(struct xfs_buf *, size_t); 333 extern void xfs_buf_stale(struct xfs_buf *bp); 334 335 /* Delayed Write Buffer Routines */ 336 extern void xfs_buf_delwri_cancel(struct list_head *); 337 extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); 338 void xfs_buf_delwri_queue_here(struct xfs_buf *bp, struct list_head *bl); 339 extern int xfs_buf_delwri_submit(struct list_head *); 340 extern int xfs_buf_delwri_submit_nowait(struct list_head *); 341 extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); 342 343 static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) 344 { 345 return bp->b_maps[0].bm_bn; 346 } 347 348 void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); 349 350 /* 351 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer 352 * up with a reference count of 0 so it will be tossed from the cache when 353 * released. 354 */ 355 static inline void xfs_buf_oneshot(struct xfs_buf *bp) 356 { 357 if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1) 358 return; 359 atomic_set(&bp->b_lru_ref, 0); 360 } 361 362 static inline int xfs_buf_ispinned(struct xfs_buf *bp) 363 { 364 return atomic_read(&bp->b_pin_count); 365 } 366 367 static inline int 368 xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 369 { 370 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), 371 cksum_offset); 372 } 373 374 static inline void 375 xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 376 { 377 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), 378 cksum_offset); 379 } 380 381 /* 382 * Handling of buftargs. 383 */ 384 struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp, 385 struct file *bdev_file); 386 extern void xfs_free_buftarg(struct xfs_buftarg *); 387 extern void xfs_buftarg_wait(struct xfs_buftarg *); 388 extern void xfs_buftarg_drain(struct xfs_buftarg *); 389 extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int); 390 391 #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) 392 #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) 393 394 int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); 395 bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic); 396 bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic); 397 398 /* for xfs_buf_mem.c only: */ 399 int xfs_init_buftarg(struct xfs_buftarg *btp, size_t logical_sectorsize, 400 const char *descr); 401 void xfs_destroy_buftarg(struct xfs_buftarg *btp); 402 403 #endif /* __XFS_BUF_H__ */ 404