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 #define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */ 48 #define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */ 49 #define XBF_UNMAPPED (1u << 31)/* do not map the buffer */ 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_NO_IOACCT, "NO_IOACCT" }, \ 59 { XBF_ASYNC, "ASYNC" }, \ 60 { XBF_DONE, "DONE" }, \ 61 { XBF_STALE, "STALE" }, \ 62 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \ 63 { _XBF_INODES, "INODES" }, \ 64 { _XBF_DQUOTS, "DQUOTS" }, \ 65 { _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \ 66 { _XBF_PAGES, "PAGES" }, \ 67 { _XBF_KMEM, "KMEM" }, \ 68 { _XBF_DELWRI_Q, "DELWRI_Q" }, \ 69 /* The following interface flags should never be set */ \ 70 { XBF_INCORE, "INCORE" }, \ 71 { XBF_TRYLOCK, "TRYLOCK" }, \ 72 { XBF_UNMAPPED, "UNMAPPED" } 73 74 /* 75 * Internal state flags. 76 */ 77 #define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */ 78 #define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */ 79 80 /* 81 * The xfs_buftarg contains 2 notions of "sector size" - 82 * 83 * 1) The metadata sector size, which is the minimum unit and 84 * alignment of IO which will be performed by metadata operations. 85 * 2) The device logical sector size 86 * 87 * The first is specified at mkfs time, and is stored on-disk in the 88 * superblock's sb_sectsize. 89 * 90 * The latter is derived from the underlying device, and controls direct IO 91 * alignment constraints. 92 */ 93 typedef struct xfs_buftarg { 94 dev_t bt_dev; 95 struct block_device *bt_bdev; 96 struct dax_device *bt_daxdev; 97 u64 bt_dax_part_off; 98 struct xfs_mount *bt_mount; 99 unsigned int bt_meta_sectorsize; 100 size_t bt_meta_sectormask; 101 size_t bt_logical_sectorsize; 102 size_t bt_logical_sectormask; 103 104 /* LRU control structures */ 105 struct shrinker bt_shrinker; 106 struct list_lru bt_lru; 107 108 struct percpu_counter bt_io_count; 109 struct ratelimit_state bt_ioerror_rl; 110 } xfs_buftarg_t; 111 112 #define XB_PAGES 2 113 114 struct xfs_buf_map { 115 xfs_daddr_t bm_bn; /* block number for I/O */ 116 int bm_len; /* size of I/O */ 117 }; 118 119 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ 120 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; 121 122 struct xfs_buf_ops { 123 char *name; 124 union { 125 __be32 magic[2]; /* v4 and v5 on disk magic values */ 126 __be16 magic16[2]; /* v4 and v5 on disk magic values */ 127 }; 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 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 */ 142 143 xfs_daddr_t b_rhash_key; /* buffer cache index */ 144 int b_length; /* size of buffer in BBs */ 145 atomic_t b_hold; /* reference count */ 146 atomic_t b_lru_ref; /* lru reclaim ref count */ 147 xfs_buf_flags_t b_flags; /* status flags */ 148 struct semaphore b_sema; /* semaphore for lockables */ 149 150 /* 151 * concurrent access to b_lru and b_lru_flags are protected by 152 * bt_lru_lock and not by b_sema 153 */ 154 struct list_head b_lru; /* lru list */ 155 spinlock_t b_lock; /* internal state lock */ 156 unsigned int b_state; /* internal state flags */ 157 int b_io_error; /* internal IO error state */ 158 wait_queue_head_t b_waiters; /* unpin waiters */ 159 struct list_head b_list; 160 struct xfs_perag *b_pag; /* contains rbtree root */ 161 struct xfs_mount *b_mount; 162 struct xfs_buftarg *b_target; /* buffer target (device) */ 163 void *b_addr; /* virtual address of buffer */ 164 struct work_struct b_ioend_work; 165 struct completion b_iowait; /* queue for I/O waiters */ 166 struct xfs_buf_log_item *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 atomic_t b_pin_count; /* pin count */ 175 atomic_t b_io_remaining; /* #outstanding I/O requests */ 176 unsigned int b_page_count; /* size of page array */ 177 unsigned int b_offset; /* page offset of b_addr, 178 only for _XBF_KMEM buffers */ 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 struct rcu_head b_rcu; 202 }; 203 204 /* Finding and Reading Buffers */ 205 int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 206 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp); 207 int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 208 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, 209 const struct xfs_buf_ops *ops, xfs_failaddr_t fa); 210 void xfs_buf_readahead_map(struct xfs_buftarg *target, 211 struct xfs_buf_map *map, int nmaps, 212 const struct xfs_buf_ops *ops); 213 214 static inline int 215 xfs_buf_incore( 216 struct xfs_buftarg *target, 217 xfs_daddr_t blkno, 218 size_t numblks, 219 xfs_buf_flags_t flags, 220 struct xfs_buf **bpp) 221 { 222 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 223 224 return xfs_buf_get_map(target, &map, 1, XBF_INCORE | flags, bpp); 225 } 226 227 static inline int 228 xfs_buf_get( 229 struct xfs_buftarg *target, 230 xfs_daddr_t blkno, 231 size_t numblks, 232 struct xfs_buf **bpp) 233 { 234 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 235 236 return xfs_buf_get_map(target, &map, 1, 0, bpp); 237 } 238 239 static inline int 240 xfs_buf_read( 241 struct xfs_buftarg *target, 242 xfs_daddr_t blkno, 243 size_t numblks, 244 xfs_buf_flags_t flags, 245 struct xfs_buf **bpp, 246 const struct xfs_buf_ops *ops) 247 { 248 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 249 250 return xfs_buf_read_map(target, &map, 1, flags, bpp, ops, 251 __builtin_return_address(0)); 252 } 253 254 static inline void 255 xfs_buf_readahead( 256 struct xfs_buftarg *target, 257 xfs_daddr_t blkno, 258 size_t numblks, 259 const struct xfs_buf_ops *ops) 260 { 261 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 262 return xfs_buf_readahead_map(target, &map, 1, ops); 263 } 264 265 int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, 266 xfs_buf_flags_t flags, struct xfs_buf **bpp); 267 int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, 268 size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp, 269 const struct xfs_buf_ops *ops); 270 int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags); 271 void xfs_buf_hold(struct xfs_buf *bp); 272 273 /* Releasing Buffers */ 274 extern void xfs_buf_rele(struct xfs_buf *); 275 276 /* Locking and Unlocking Buffers */ 277 extern int xfs_buf_trylock(struct xfs_buf *); 278 extern void xfs_buf_lock(struct xfs_buf *); 279 extern void xfs_buf_unlock(struct xfs_buf *); 280 #define xfs_buf_islocked(bp) \ 281 ((bp)->b_sema.count <= 0) 282 283 static inline void xfs_buf_relse(struct xfs_buf *bp) 284 { 285 xfs_buf_unlock(bp); 286 xfs_buf_rele(bp); 287 } 288 289 /* Buffer Read and Write Routines */ 290 extern int xfs_bwrite(struct xfs_buf *bp); 291 292 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 *bp, xfs_failaddr_t fa); 296 void xfs_buf_ioend_fail(struct xfs_buf *); 297 void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize); 298 void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa); 299 #define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address) 300 301 /* Buffer Utility Routines */ 302 extern void *xfs_buf_offset(struct xfs_buf *, size_t); 303 extern void xfs_buf_stale(struct xfs_buf *bp); 304 305 /* Delayed Write Buffer Routines */ 306 extern void xfs_buf_delwri_cancel(struct list_head *); 307 extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); 308 extern int xfs_buf_delwri_submit(struct list_head *); 309 extern int xfs_buf_delwri_submit_nowait(struct list_head *); 310 extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); 311 312 static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) 313 { 314 return bp->b_maps[0].bm_bn; 315 } 316 317 void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); 318 319 /* 320 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer 321 * up with a reference count of 0 so it will be tossed from the cache when 322 * released. 323 */ 324 static inline void xfs_buf_oneshot(struct xfs_buf *bp) 325 { 326 if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1) 327 return; 328 atomic_set(&bp->b_lru_ref, 0); 329 } 330 331 static inline int xfs_buf_ispinned(struct xfs_buf *bp) 332 { 333 return atomic_read(&bp->b_pin_count); 334 } 335 336 static inline int 337 xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 338 { 339 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), 340 cksum_offset); 341 } 342 343 static inline void 344 xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 345 { 346 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), 347 cksum_offset); 348 } 349 350 /* 351 * Handling of buftargs. 352 */ 353 struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp, 354 struct block_device *bdev); 355 extern void xfs_free_buftarg(struct xfs_buftarg *); 356 extern void xfs_buftarg_wait(struct xfs_buftarg *); 357 extern void xfs_buftarg_drain(struct xfs_buftarg *); 358 extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int); 359 360 #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) 361 #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) 362 363 int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); 364 bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic); 365 bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic); 366 367 #endif /* __XFS_BUF_H__ */ 368