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 /* 19 * Base types 20 */ 21 22 #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL)) 23 24 typedef enum { 25 XBRW_READ = 1, /* transfer into target memory */ 26 XBRW_WRITE = 2, /* transfer from target memory */ 27 XBRW_ZERO = 3, /* Zero target memory */ 28 } xfs_buf_rw_t; 29 30 #define XBF_READ (1 << 0) /* buffer intended for reading from device */ 31 #define XBF_WRITE (1 << 1) /* buffer intended for writing to device */ 32 #define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */ 33 #define XBF_NO_IOACCT (1 << 3) /* bypass I/O accounting (non-LRU bufs) */ 34 #define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */ 35 #define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */ 36 #define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */ 37 #define XBF_WRITE_FAIL (1 << 24)/* async writes have failed on this buffer */ 38 39 /* I/O hints for the BIO layer */ 40 #define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */ 41 #define XBF_FUA (1 << 11)/* force cache write through mode */ 42 #define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */ 43 44 /* flags used only as arguments to access routines */ 45 #define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */ 46 #define XBF_UNMAPPED (1 << 17)/* do not map the buffer */ 47 48 /* flags used only internally */ 49 #define _XBF_PAGES (1 << 20)/* backed by refcounted pages */ 50 #define _XBF_KMEM (1 << 21)/* backed by heap memory */ 51 #define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */ 52 #define _XBF_COMPOUND (1 << 23)/* compound buffer */ 53 54 typedef unsigned int xfs_buf_flags_t; 55 56 #define XFS_BUF_FLAGS \ 57 { XBF_READ, "READ" }, \ 58 { XBF_WRITE, "WRITE" }, \ 59 { XBF_READ_AHEAD, "READ_AHEAD" }, \ 60 { XBF_NO_IOACCT, "NO_IOACCT" }, \ 61 { XBF_ASYNC, "ASYNC" }, \ 62 { XBF_DONE, "DONE" }, \ 63 { XBF_STALE, "STALE" }, \ 64 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \ 65 { XBF_SYNCIO, "SYNCIO" }, \ 66 { XBF_FUA, "FUA" }, \ 67 { XBF_FLUSH, "FLUSH" }, \ 68 { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\ 69 { XBF_UNMAPPED, "UNMAPPED" }, /* ditto */\ 70 { _XBF_PAGES, "PAGES" }, \ 71 { _XBF_KMEM, "KMEM" }, \ 72 { _XBF_DELWRI_Q, "DELWRI_Q" }, \ 73 { _XBF_COMPOUND, "COMPOUND" } 74 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 /* 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 typedef struct xfs_buftarg { 96 dev_t bt_dev; 97 struct block_device *bt_bdev; 98 struct dax_device *bt_daxdev; 99 struct xfs_mount *bt_mount; 100 unsigned int bt_meta_sectorsize; 101 size_t bt_meta_sectormask; 102 size_t bt_logical_sectorsize; 103 size_t bt_logical_sectormask; 104 105 /* LRU control structures */ 106 struct shrinker bt_shrinker; 107 struct list_lru bt_lru; 108 109 struct percpu_counter bt_io_count; 110 } xfs_buftarg_t; 111 112 struct xfs_buf; 113 typedef void (*xfs_buf_iodone_t)(struct xfs_buf *); 114 115 116 #define XB_PAGES 2 117 118 struct xfs_buf_map { 119 xfs_daddr_t bm_bn; /* block number for I/O */ 120 int bm_len; /* size of I/O */ 121 }; 122 123 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ 124 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; 125 126 struct xfs_buf_ops { 127 char *name; 128 void (*verify_read)(struct xfs_buf *); 129 void (*verify_write)(struct xfs_buf *); 130 xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); 131 }; 132 133 typedef struct xfs_buf { 134 /* 135 * first cacheline holds all the fields needed for an uncontended cache 136 * hit to be fully processed. The semaphore straddles the cacheline 137 * boundary, but the counter and lock sits on the first cacheline, 138 * which is the only bit that is touched if we hit the semaphore 139 * fast-path on locking. 140 */ 141 struct rhash_head b_rhash_head; /* pag buffer hash node */ 142 xfs_daddr_t b_bn; /* block number of buffer */ 143 int b_length; /* size of buffer in BBs */ 144 atomic_t b_hold; /* reference count */ 145 atomic_t b_lru_ref; /* lru reclaim ref count */ 146 xfs_buf_flags_t b_flags; /* status flags */ 147 struct semaphore b_sema; /* semaphore for lockables */ 148 149 /* 150 * concurrent access to b_lru and b_lru_flags are protected by 151 * bt_lru_lock and not by b_sema 152 */ 153 struct list_head b_lru; /* lru list */ 154 spinlock_t b_lock; /* internal state lock */ 155 unsigned int b_state; /* internal state flags */ 156 int b_io_error; /* internal IO error state */ 157 wait_queue_head_t b_waiters; /* unpin waiters */ 158 struct list_head b_list; 159 struct xfs_perag *b_pag; /* contains rbtree root */ 160 xfs_buftarg_t *b_target; /* buffer target (device) */ 161 void *b_addr; /* virtual address of buffer */ 162 struct work_struct b_ioend_work; 163 struct workqueue_struct *b_ioend_wq; /* I/O completion wq */ 164 xfs_buf_iodone_t b_iodone; /* I/O completion function */ 165 struct completion b_iowait; /* queue for I/O waiters */ 166 void *b_log_item; 167 struct list_head b_li_list; /* Log items list head */ 168 struct xfs_trans *b_transp; 169 struct page **b_pages; /* array of page pointers */ 170 struct page *b_page_array[XB_PAGES]; /* inline pages */ 171 struct xfs_buf_map *b_maps; /* compound buffer map */ 172 struct xfs_buf_map __b_map; /* inline compound buffer map */ 173 int b_map_count; 174 int b_io_length; /* IO size in BBs */ 175 atomic_t b_pin_count; /* pin count */ 176 atomic_t b_io_remaining; /* #outstanding I/O requests */ 177 unsigned int b_page_count; /* size of page array */ 178 unsigned int b_offset; /* page offset in first page */ 179 int b_error; /* error code on I/O */ 180 181 /* 182 * async write failure retry count. Initialised to zero on the first 183 * failure, then when it exceeds the maximum configured without a 184 * success the write is considered to be failed permanently and the 185 * iodone handler will take appropriate action. 186 * 187 * For retry timeouts, we record the jiffie of the first failure. This 188 * means that we can change the retry timeout for buffers already under 189 * I/O and thus avoid getting stuck in a retry loop with a long timeout. 190 * 191 * last_error is used to ensure that we are getting repeated errors, not 192 * different errors. e.g. a block device might change ENOSPC to EIO when 193 * a failure timeout occurs, so we want to re-initialise the error 194 * retry behaviour appropriately when that happens. 195 */ 196 int b_retries; 197 unsigned long b_first_retry_time; /* in jiffies */ 198 int b_last_error; 199 200 const struct xfs_buf_ops *b_ops; 201 } xfs_buf_t; 202 203 /* Finding and Reading Buffers */ 204 struct xfs_buf *xfs_buf_incore(struct xfs_buftarg *target, 205 xfs_daddr_t blkno, size_t numblks, 206 xfs_buf_flags_t flags); 207 208 struct xfs_buf *_xfs_buf_alloc(struct xfs_buftarg *target, 209 struct xfs_buf_map *map, int nmaps, 210 xfs_buf_flags_t flags); 211 212 static inline struct xfs_buf * 213 xfs_buf_alloc( 214 struct xfs_buftarg *target, 215 xfs_daddr_t blkno, 216 size_t numblks, 217 xfs_buf_flags_t flags) 218 { 219 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 220 return _xfs_buf_alloc(target, &map, 1, flags); 221 } 222 223 struct xfs_buf *xfs_buf_get_map(struct xfs_buftarg *target, 224 struct xfs_buf_map *map, int nmaps, 225 xfs_buf_flags_t flags); 226 struct xfs_buf *xfs_buf_read_map(struct xfs_buftarg *target, 227 struct xfs_buf_map *map, int nmaps, 228 xfs_buf_flags_t flags, 229 const struct xfs_buf_ops *ops); 230 void xfs_buf_readahead_map(struct xfs_buftarg *target, 231 struct xfs_buf_map *map, int nmaps, 232 const struct xfs_buf_ops *ops); 233 234 static inline struct xfs_buf * 235 xfs_buf_get( 236 struct xfs_buftarg *target, 237 xfs_daddr_t blkno, 238 size_t numblks, 239 xfs_buf_flags_t flags) 240 { 241 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 242 return xfs_buf_get_map(target, &map, 1, flags); 243 } 244 245 static inline struct xfs_buf * 246 xfs_buf_read( 247 struct xfs_buftarg *target, 248 xfs_daddr_t blkno, 249 size_t numblks, 250 xfs_buf_flags_t flags, 251 const struct xfs_buf_ops *ops) 252 { 253 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 254 return xfs_buf_read_map(target, &map, 1, flags, ops); 255 } 256 257 static inline void 258 xfs_buf_readahead( 259 struct xfs_buftarg *target, 260 xfs_daddr_t blkno, 261 size_t numblks, 262 const struct xfs_buf_ops *ops) 263 { 264 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 265 return xfs_buf_readahead_map(target, &map, 1, ops); 266 } 267 268 void xfs_buf_set_empty(struct xfs_buf *bp, size_t numblks); 269 int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length); 270 271 struct xfs_buf *xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, 272 int flags); 273 int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, 274 size_t numblks, int flags, struct xfs_buf **bpp, 275 const struct xfs_buf_ops *ops); 276 void xfs_buf_hold(struct xfs_buf *bp); 277 278 /* Releasing Buffers */ 279 extern void xfs_buf_free(xfs_buf_t *); 280 extern void xfs_buf_rele(xfs_buf_t *); 281 282 /* Locking and Unlocking Buffers */ 283 extern int xfs_buf_trylock(xfs_buf_t *); 284 extern void xfs_buf_lock(xfs_buf_t *); 285 extern void xfs_buf_unlock(xfs_buf_t *); 286 #define xfs_buf_islocked(bp) \ 287 ((bp)->b_sema.count <= 0) 288 289 /* Buffer Read and Write Routines */ 290 extern int xfs_bwrite(struct xfs_buf *bp); 291 extern void xfs_buf_ioend(struct xfs_buf *bp); 292 extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, 293 xfs_failaddr_t failaddr); 294 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) 295 extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func); 296 297 extern int __xfs_buf_submit(struct xfs_buf *bp, bool); 298 static inline int xfs_buf_submit(struct xfs_buf *bp) 299 { 300 bool wait = bp->b_flags & XBF_ASYNC ? false : true; 301 return __xfs_buf_submit(bp, wait); 302 } 303 304 extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *, 305 xfs_buf_rw_t); 306 #define xfs_buf_zero(bp, off, len) \ 307 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO) 308 309 /* Buffer Utility Routines */ 310 extern void *xfs_buf_offset(struct xfs_buf *, size_t); 311 extern void xfs_buf_stale(struct xfs_buf *bp); 312 313 /* Delayed Write Buffer Routines */ 314 extern void xfs_buf_delwri_cancel(struct list_head *); 315 extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); 316 extern int xfs_buf_delwri_submit(struct list_head *); 317 extern int xfs_buf_delwri_submit_nowait(struct list_head *); 318 extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); 319 320 /* Buffer Daemon Setup Routines */ 321 extern int xfs_buf_init(void); 322 extern void xfs_buf_terminate(void); 323 324 /* 325 * These macros use the IO block map rather than b_bn. b_bn is now really 326 * just for the buffer cache index for cached buffers. As IO does not use b_bn 327 * anymore, uncached buffers do not use b_bn at all and hence must modify the IO 328 * map directly. Uncached buffers are not allowed to be discontiguous, so this 329 * is safe to do. 330 * 331 * In future, uncached buffers will pass the block number directly to the io 332 * request function and hence these macros will go away at that point. 333 */ 334 #define XFS_BUF_ADDR(bp) ((bp)->b_maps[0].bm_bn) 335 #define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno)) 336 337 void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); 338 339 /* 340 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer 341 * up with a reference count of 0 so it will be tossed from the cache when 342 * released. 343 */ 344 static inline void xfs_buf_oneshot(struct xfs_buf *bp) 345 { 346 if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1) 347 return; 348 atomic_set(&bp->b_lru_ref, 0); 349 } 350 351 static inline int xfs_buf_ispinned(struct xfs_buf *bp) 352 { 353 return atomic_read(&bp->b_pin_count); 354 } 355 356 static inline void xfs_buf_relse(xfs_buf_t *bp) 357 { 358 xfs_buf_unlock(bp); 359 xfs_buf_rele(bp); 360 } 361 362 static inline int 363 xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 364 { 365 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), 366 cksum_offset); 367 } 368 369 static inline void 370 xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 371 { 372 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), 373 cksum_offset); 374 } 375 376 /* 377 * Handling of buftargs. 378 */ 379 extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *, 380 struct block_device *, struct dax_device *); 381 extern void xfs_free_buftarg(struct xfs_buftarg *); 382 extern void xfs_wait_buftarg(xfs_buftarg_t *); 383 extern int xfs_setsize_buftarg(xfs_buftarg_t *, 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 #endif /* __XFS_BUF_H__ */ 389