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 struct xfs_buf; 22 23 #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL)) 24 25 #define XBF_READ (1u << 0) /* buffer intended for reading from device */ 26 #define XBF_WRITE (1u << 1) /* buffer intended for writing to device */ 27 #define XBF_READ_AHEAD (1u << 2) /* asynchronous read-ahead */ 28 #define XBF_NO_IOACCT (1u << 3) /* bypass I/O accounting (non-LRU bufs) */ 29 #define XBF_ASYNC (1u << 4) /* initiator will not wait for completion */ 30 #define XBF_DONE (1u << 5) /* all pages in the buffer uptodate */ 31 #define XBF_STALE (1u << 6) /* buffer has been staled, do not find it */ 32 #define XBF_WRITE_FAIL (1u << 7) /* async writes have failed on this buffer */ 33 34 /* buffer type flags for write callbacks */ 35 #define _XBF_INODES (1u << 16)/* inode buffer */ 36 #define _XBF_DQUOTS (1u << 17)/* dquot buffer */ 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 #define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */ 46 #define XBF_UNMAPPED (1u << 31)/* do not map the buffer */ 47 48 typedef unsigned int xfs_buf_flags_t; 49 50 #define XFS_BUF_FLAGS \ 51 { XBF_READ, "READ" }, \ 52 { XBF_WRITE, "WRITE" }, \ 53 { XBF_READ_AHEAD, "READ_AHEAD" }, \ 54 { XBF_NO_IOACCT, "NO_IOACCT" }, \ 55 { XBF_ASYNC, "ASYNC" }, \ 56 { XBF_DONE, "DONE" }, \ 57 { XBF_STALE, "STALE" }, \ 58 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \ 59 { _XBF_INODES, "INODES" }, \ 60 { _XBF_DQUOTS, "DQUOTS" }, \ 61 { _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \ 62 { _XBF_PAGES, "PAGES" }, \ 63 { _XBF_KMEM, "KMEM" }, \ 64 { _XBF_DELWRI_Q, "DELWRI_Q" }, \ 65 /* The following interface flags should never be set */ \ 66 { XBF_TRYLOCK, "TRYLOCK" }, \ 67 { XBF_UNMAPPED, "UNMAPPED" } 68 69 /* 70 * Internal state flags. 71 */ 72 #define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */ 73 #define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */ 74 75 /* 76 * The xfs_buftarg contains 2 notions of "sector size" - 77 * 78 * 1) The metadata sector size, which is the minimum unit and 79 * alignment of IO which will be performed by metadata operations. 80 * 2) The device logical sector size 81 * 82 * The first is specified at mkfs time, and is stored on-disk in the 83 * superblock's sb_sectsize. 84 * 85 * The latter is derived from the underlying device, and controls direct IO 86 * alignment constraints. 87 */ 88 typedef struct xfs_buftarg { 89 dev_t bt_dev; 90 struct block_device *bt_bdev; 91 struct dax_device *bt_daxdev; 92 u64 bt_dax_part_off; 93 struct xfs_mount *bt_mount; 94 unsigned int bt_meta_sectorsize; 95 size_t bt_meta_sectormask; 96 size_t bt_logical_sectorsize; 97 size_t bt_logical_sectormask; 98 99 /* LRU control structures */ 100 struct shrinker bt_shrinker; 101 struct list_lru bt_lru; 102 103 struct percpu_counter bt_io_count; 104 struct ratelimit_state bt_ioerror_rl; 105 } xfs_buftarg_t; 106 107 #define XB_PAGES 2 108 109 struct xfs_buf_map { 110 xfs_daddr_t bm_bn; /* block number for I/O */ 111 int bm_len; /* size of I/O */ 112 }; 113 114 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ 115 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; 116 117 struct xfs_buf_ops { 118 char *name; 119 union { 120 __be32 magic[2]; /* v4 and v5 on disk magic values */ 121 __be16 magic16[2]; /* v4 and v5 on disk magic values */ 122 }; 123 void (*verify_read)(struct xfs_buf *); 124 void (*verify_write)(struct xfs_buf *); 125 xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); 126 }; 127 128 struct xfs_buf { 129 /* 130 * first cacheline holds all the fields needed for an uncontended cache 131 * hit to be fully processed. The semaphore straddles the cacheline 132 * boundary, but the counter and lock sits on the first cacheline, 133 * which is the only bit that is touched if we hit the semaphore 134 * fast-path on locking. 135 */ 136 struct rhash_head b_rhash_head; /* pag buffer hash node */ 137 138 xfs_daddr_t b_rhash_key; /* buffer cache index */ 139 int b_length; /* size of buffer in BBs */ 140 atomic_t b_hold; /* reference count */ 141 atomic_t b_lru_ref; /* lru reclaim ref count */ 142 xfs_buf_flags_t b_flags; /* status flags */ 143 struct semaphore b_sema; /* semaphore for lockables */ 144 145 /* 146 * concurrent access to b_lru and b_lru_flags are protected by 147 * bt_lru_lock and not by b_sema 148 */ 149 struct list_head b_lru; /* lru list */ 150 spinlock_t b_lock; /* internal state lock */ 151 unsigned int b_state; /* internal state flags */ 152 int b_io_error; /* internal IO error state */ 153 wait_queue_head_t b_waiters; /* unpin waiters */ 154 struct list_head b_list; 155 struct xfs_perag *b_pag; /* contains rbtree root */ 156 struct xfs_mount *b_mount; 157 struct xfs_buftarg *b_target; /* buffer target (device) */ 158 void *b_addr; /* virtual address of buffer */ 159 struct work_struct b_ioend_work; 160 struct completion b_iowait; /* queue for I/O waiters */ 161 struct xfs_buf_log_item *b_log_item; 162 struct list_head b_li_list; /* Log items list head */ 163 struct xfs_trans *b_transp; 164 struct page **b_pages; /* array of page pointers */ 165 struct page *b_page_array[XB_PAGES]; /* inline pages */ 166 struct xfs_buf_map *b_maps; /* compound buffer map */ 167 struct xfs_buf_map __b_map; /* inline compound buffer map */ 168 int b_map_count; 169 atomic_t b_pin_count; /* pin count */ 170 atomic_t b_io_remaining; /* #outstanding I/O requests */ 171 unsigned int b_page_count; /* size of page array */ 172 unsigned int b_offset; /* page offset of b_addr, 173 only for _XBF_KMEM buffers */ 174 int b_error; /* error code on I/O */ 175 176 /* 177 * async write failure retry count. Initialised to zero on the first 178 * failure, then when it exceeds the maximum configured without a 179 * success the write is considered to be failed permanently and the 180 * iodone handler will take appropriate action. 181 * 182 * For retry timeouts, we record the jiffie of the first failure. This 183 * means that we can change the retry timeout for buffers already under 184 * I/O and thus avoid getting stuck in a retry loop with a long timeout. 185 * 186 * last_error is used to ensure that we are getting repeated errors, not 187 * different errors. e.g. a block device might change ENOSPC to EIO when 188 * a failure timeout occurs, so we want to re-initialise the error 189 * retry behaviour appropriately when that happens. 190 */ 191 int b_retries; 192 unsigned long b_first_retry_time; /* in jiffies */ 193 int b_last_error; 194 195 const struct xfs_buf_ops *b_ops; 196 }; 197 198 /* Finding and Reading Buffers */ 199 struct xfs_buf *xfs_buf_incore(struct xfs_buftarg *target, 200 xfs_daddr_t blkno, size_t numblks, 201 xfs_buf_flags_t flags); 202 203 int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 204 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp); 205 int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 206 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, 207 const struct xfs_buf_ops *ops, xfs_failaddr_t fa); 208 void xfs_buf_readahead_map(struct xfs_buftarg *target, 209 struct xfs_buf_map *map, int nmaps, 210 const struct xfs_buf_ops *ops); 211 212 static inline int 213 xfs_buf_get( 214 struct xfs_buftarg *target, 215 xfs_daddr_t blkno, 216 size_t numblks, 217 struct xfs_buf **bpp) 218 { 219 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 220 221 return xfs_buf_get_map(target, &map, 1, 0, bpp); 222 } 223 224 static inline int 225 xfs_buf_read( 226 struct xfs_buftarg *target, 227 xfs_daddr_t blkno, 228 size_t numblks, 229 xfs_buf_flags_t flags, 230 struct xfs_buf **bpp, 231 const struct xfs_buf_ops *ops) 232 { 233 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 234 235 return xfs_buf_read_map(target, &map, 1, flags, bpp, ops, 236 __builtin_return_address(0)); 237 } 238 239 static inline void 240 xfs_buf_readahead( 241 struct xfs_buftarg *target, 242 xfs_daddr_t blkno, 243 size_t numblks, 244 const struct xfs_buf_ops *ops) 245 { 246 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 247 return xfs_buf_readahead_map(target, &map, 1, ops); 248 } 249 250 int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, 251 xfs_buf_flags_t flags, struct xfs_buf **bpp); 252 int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, 253 size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp, 254 const struct xfs_buf_ops *ops); 255 int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags); 256 void xfs_buf_hold(struct xfs_buf *bp); 257 258 /* Releasing Buffers */ 259 extern void xfs_buf_rele(struct xfs_buf *); 260 261 /* Locking and Unlocking Buffers */ 262 extern int xfs_buf_trylock(struct xfs_buf *); 263 extern void xfs_buf_lock(struct xfs_buf *); 264 extern void xfs_buf_unlock(struct xfs_buf *); 265 #define xfs_buf_islocked(bp) \ 266 ((bp)->b_sema.count <= 0) 267 268 static inline void xfs_buf_relse(struct xfs_buf *bp) 269 { 270 xfs_buf_unlock(bp); 271 xfs_buf_rele(bp); 272 } 273 274 /* Buffer Read and Write Routines */ 275 extern int xfs_bwrite(struct xfs_buf *bp); 276 277 extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, 278 xfs_failaddr_t failaddr); 279 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) 280 extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa); 281 void xfs_buf_ioend_fail(struct xfs_buf *); 282 void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize); 283 void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa); 284 #define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address) 285 286 /* Buffer Utility Routines */ 287 extern void *xfs_buf_offset(struct xfs_buf *, size_t); 288 extern void xfs_buf_stale(struct xfs_buf *bp); 289 290 /* Delayed Write Buffer Routines */ 291 extern void xfs_buf_delwri_cancel(struct list_head *); 292 extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); 293 extern int xfs_buf_delwri_submit(struct list_head *); 294 extern int xfs_buf_delwri_submit_nowait(struct list_head *); 295 extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); 296 297 /* Buffer Daemon Setup Routines */ 298 extern int xfs_buf_init(void); 299 extern void xfs_buf_terminate(void); 300 301 static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) 302 { 303 return bp->b_maps[0].bm_bn; 304 } 305 306 void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); 307 308 /* 309 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer 310 * up with a reference count of 0 so it will be tossed from the cache when 311 * released. 312 */ 313 static inline void xfs_buf_oneshot(struct xfs_buf *bp) 314 { 315 if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1) 316 return; 317 atomic_set(&bp->b_lru_ref, 0); 318 } 319 320 static inline int xfs_buf_ispinned(struct xfs_buf *bp) 321 { 322 return atomic_read(&bp->b_pin_count); 323 } 324 325 static inline int 326 xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 327 { 328 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), 329 cksum_offset); 330 } 331 332 static inline void 333 xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 334 { 335 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), 336 cksum_offset); 337 } 338 339 /* 340 * Handling of buftargs. 341 */ 342 struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp, 343 struct block_device *bdev); 344 extern void xfs_free_buftarg(struct xfs_buftarg *); 345 extern void xfs_buftarg_wait(struct xfs_buftarg *); 346 extern void xfs_buftarg_drain(struct xfs_buftarg *); 347 extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int); 348 349 #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) 350 #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) 351 352 int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); 353 bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic); 354 bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic); 355 356 #endif /* __XFS_BUF_H__ */ 357