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 union { 129 __be32 magic[2]; /* v4 and v5 on disk magic values */ 130 __be16 magic16[2]; /* v4 and v5 on disk magic values */ 131 }; 132 void (*verify_read)(struct xfs_buf *); 133 void (*verify_write)(struct xfs_buf *); 134 xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); 135 }; 136 137 typedef struct xfs_buf { 138 /* 139 * first cacheline holds all the fields needed for an uncontended cache 140 * hit to be fully processed. The semaphore straddles the cacheline 141 * boundary, but the counter and lock sits on the first cacheline, 142 * which is the only bit that is touched if we hit the semaphore 143 * fast-path on locking. 144 */ 145 struct rhash_head b_rhash_head; /* pag buffer hash node */ 146 xfs_daddr_t b_bn; /* block number of buffer */ 147 int b_length; /* size of buffer in BBs */ 148 atomic_t b_hold; /* reference count */ 149 atomic_t b_lru_ref; /* lru reclaim ref count */ 150 xfs_buf_flags_t b_flags; /* status flags */ 151 struct semaphore b_sema; /* semaphore for lockables */ 152 153 /* 154 * concurrent access to b_lru and b_lru_flags are protected by 155 * bt_lru_lock and not by b_sema 156 */ 157 struct list_head b_lru; /* lru list */ 158 spinlock_t b_lock; /* internal state lock */ 159 unsigned int b_state; /* internal state flags */ 160 int b_io_error; /* internal IO error state */ 161 wait_queue_head_t b_waiters; /* unpin waiters */ 162 struct list_head b_list; 163 struct xfs_perag *b_pag; /* contains rbtree root */ 164 xfs_buftarg_t *b_target; /* buffer target (device) */ 165 void *b_addr; /* virtual address of buffer */ 166 struct work_struct b_ioend_work; 167 struct workqueue_struct *b_ioend_wq; /* I/O completion wq */ 168 xfs_buf_iodone_t b_iodone; /* I/O completion function */ 169 struct completion b_iowait; /* queue for I/O waiters */ 170 void *b_log_item; 171 struct list_head b_li_list; /* Log items list head */ 172 struct xfs_trans *b_transp; 173 struct page **b_pages; /* array of page pointers */ 174 struct page *b_page_array[XB_PAGES]; /* inline pages */ 175 struct xfs_buf_map *b_maps; /* compound buffer map */ 176 struct xfs_buf_map __b_map; /* inline compound buffer map */ 177 int b_map_count; 178 int b_io_length; /* IO size in BBs */ 179 atomic_t b_pin_count; /* pin count */ 180 atomic_t b_io_remaining; /* #outstanding I/O requests */ 181 unsigned int b_page_count; /* size of page array */ 182 unsigned int b_offset; /* page offset in first page */ 183 int b_error; /* error code on I/O */ 184 185 /* 186 * async write failure retry count. Initialised to zero on the first 187 * failure, then when it exceeds the maximum configured without a 188 * success the write is considered to be failed permanently and the 189 * iodone handler will take appropriate action. 190 * 191 * For retry timeouts, we record the jiffie of the first failure. This 192 * means that we can change the retry timeout for buffers already under 193 * I/O and thus avoid getting stuck in a retry loop with a long timeout. 194 * 195 * last_error is used to ensure that we are getting repeated errors, not 196 * different errors. e.g. a block device might change ENOSPC to EIO when 197 * a failure timeout occurs, so we want to re-initialise the error 198 * retry behaviour appropriately when that happens. 199 */ 200 int b_retries; 201 unsigned long b_first_retry_time; /* in jiffies */ 202 int b_last_error; 203 204 const struct xfs_buf_ops *b_ops; 205 } xfs_buf_t; 206 207 /* Finding and Reading Buffers */ 208 struct xfs_buf *xfs_buf_incore(struct xfs_buftarg *target, 209 xfs_daddr_t blkno, size_t numblks, 210 xfs_buf_flags_t flags); 211 212 struct xfs_buf *_xfs_buf_alloc(struct xfs_buftarg *target, 213 struct xfs_buf_map *map, int nmaps, 214 xfs_buf_flags_t flags); 215 216 static inline struct xfs_buf * 217 xfs_buf_alloc( 218 struct xfs_buftarg *target, 219 xfs_daddr_t blkno, 220 size_t numblks, 221 xfs_buf_flags_t flags) 222 { 223 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 224 return _xfs_buf_alloc(target, &map, 1, flags); 225 } 226 227 struct xfs_buf *xfs_buf_get_map(struct xfs_buftarg *target, 228 struct xfs_buf_map *map, int nmaps, 229 xfs_buf_flags_t flags); 230 struct xfs_buf *xfs_buf_read_map(struct xfs_buftarg *target, 231 struct xfs_buf_map *map, int nmaps, 232 xfs_buf_flags_t flags, 233 const struct xfs_buf_ops *ops); 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 struct xfs_buf * 239 xfs_buf_get( 240 struct xfs_buftarg *target, 241 xfs_daddr_t blkno, 242 size_t numblks, 243 xfs_buf_flags_t flags) 244 { 245 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 246 return xfs_buf_get_map(target, &map, 1, flags); 247 } 248 249 static inline struct xfs_buf * 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 const struct xfs_buf_ops *ops) 256 { 257 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 258 return xfs_buf_read_map(target, &map, 1, flags, ops); 259 } 260 261 static inline void 262 xfs_buf_readahead( 263 struct xfs_buftarg *target, 264 xfs_daddr_t blkno, 265 size_t numblks, 266 const struct xfs_buf_ops *ops) 267 { 268 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 269 return xfs_buf_readahead_map(target, &map, 1, ops); 270 } 271 272 void xfs_buf_set_empty(struct xfs_buf *bp, size_t numblks); 273 int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length); 274 275 struct xfs_buf *xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, 276 int flags); 277 int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, 278 size_t numblks, int flags, struct xfs_buf **bpp, 279 const struct xfs_buf_ops *ops); 280 void xfs_buf_hold(struct xfs_buf *bp); 281 282 /* Releasing Buffers */ 283 extern void xfs_buf_free(xfs_buf_t *); 284 extern void xfs_buf_rele(xfs_buf_t *); 285 286 /* Locking and Unlocking Buffers */ 287 extern int xfs_buf_trylock(xfs_buf_t *); 288 extern void xfs_buf_lock(xfs_buf_t *); 289 extern void xfs_buf_unlock(xfs_buf_t *); 290 #define xfs_buf_islocked(bp) \ 291 ((bp)->b_sema.count <= 0) 292 293 /* Buffer Read and Write Routines */ 294 extern int xfs_bwrite(struct xfs_buf *bp); 295 extern void xfs_buf_ioend(struct xfs_buf *bp); 296 extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, 297 xfs_failaddr_t failaddr); 298 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) 299 extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func); 300 301 extern int __xfs_buf_submit(struct xfs_buf *bp, bool); 302 static inline int xfs_buf_submit(struct xfs_buf *bp) 303 { 304 bool wait = bp->b_flags & XBF_ASYNC ? false : true; 305 return __xfs_buf_submit(bp, wait); 306 } 307 308 extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *, 309 xfs_buf_rw_t); 310 #define xfs_buf_zero(bp, off, len) \ 311 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO) 312 313 /* Buffer Utility Routines */ 314 extern void *xfs_buf_offset(struct xfs_buf *, size_t); 315 extern void xfs_buf_stale(struct xfs_buf *bp); 316 317 /* Delayed Write Buffer Routines */ 318 extern void xfs_buf_delwri_cancel(struct list_head *); 319 extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); 320 extern int xfs_buf_delwri_submit(struct list_head *); 321 extern int xfs_buf_delwri_submit_nowait(struct list_head *); 322 extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); 323 324 /* Buffer Daemon Setup Routines */ 325 extern int xfs_buf_init(void); 326 extern void xfs_buf_terminate(void); 327 328 /* 329 * These macros use the IO block map rather than b_bn. b_bn is now really 330 * just for the buffer cache index for cached buffers. As IO does not use b_bn 331 * anymore, uncached buffers do not use b_bn at all and hence must modify the IO 332 * map directly. Uncached buffers are not allowed to be discontiguous, so this 333 * is safe to do. 334 * 335 * In future, uncached buffers will pass the block number directly to the io 336 * request function and hence these macros will go away at that point. 337 */ 338 #define XFS_BUF_ADDR(bp) ((bp)->b_maps[0].bm_bn) 339 #define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno)) 340 341 void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); 342 343 /* 344 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer 345 * up with a reference count of 0 so it will be tossed from the cache when 346 * released. 347 */ 348 static inline void xfs_buf_oneshot(struct xfs_buf *bp) 349 { 350 if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1) 351 return; 352 atomic_set(&bp->b_lru_ref, 0); 353 } 354 355 static inline int xfs_buf_ispinned(struct xfs_buf *bp) 356 { 357 return atomic_read(&bp->b_pin_count); 358 } 359 360 static inline void xfs_buf_relse(xfs_buf_t *bp) 361 { 362 xfs_buf_unlock(bp); 363 xfs_buf_rele(bp); 364 } 365 366 static inline int 367 xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 368 { 369 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), 370 cksum_offset); 371 } 372 373 static inline void 374 xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 375 { 376 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), 377 cksum_offset); 378 } 379 380 /* 381 * Handling of buftargs. 382 */ 383 extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *, 384 struct block_device *, struct dax_device *); 385 extern void xfs_free_buftarg(struct xfs_buftarg *); 386 extern void xfs_wait_buftarg(xfs_buftarg_t *); 387 extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int); 388 389 #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) 390 #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) 391 392 int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); 393 bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic); 394 bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic); 395 396 #endif /* __XFS_BUF_H__ */ 397