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 (1 << 0) /* buffer intended for reading from device */ 26 #define XBF_WRITE (1 << 1) /* buffer intended for writing to device */ 27 #define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */ 28 #define XBF_NO_IOACCT (1 << 3) /* bypass I/O accounting (non-LRU bufs) */ 29 #define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */ 30 #define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */ 31 #define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */ 32 #define XBF_WRITE_FAIL (1 << 7) /* async writes have failed on this buffer */ 33 34 /* buffer type flags for write callbacks */ 35 #define _XBF_INODES (1 << 16)/* inode buffer */ 36 #define _XBF_DQUOTS (1 << 17)/* dquot buffer */ 37 #define _XBF_LOGRECOVERY (1 << 18)/* log recovery buffer */ 38 39 /* flags used only internally */ 40 #define _XBF_PAGES (1 << 20)/* backed by refcounted pages */ 41 #define _XBF_KMEM (1 << 21)/* backed by heap memory */ 42 #define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */ 43 44 /* flags used only as arguments to access routines */ 45 #define XBF_TRYLOCK (1 << 30)/* lock requested, but do not wait */ 46 #define XBF_UNMAPPED (1 << 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 struct xfs_mount *bt_mount; 93 unsigned int bt_meta_sectorsize; 94 size_t bt_meta_sectormask; 95 size_t bt_logical_sectorsize; 96 size_t bt_logical_sectormask; 97 98 /* LRU control structures */ 99 struct shrinker bt_shrinker; 100 struct list_lru bt_lru; 101 102 struct percpu_counter bt_io_count; 103 struct ratelimit_state bt_ioerror_rl; 104 } xfs_buftarg_t; 105 106 #define XB_PAGES 2 107 108 struct xfs_buf_map { 109 xfs_daddr_t bm_bn; /* block number for I/O */ 110 int bm_len; /* size of I/O */ 111 }; 112 113 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ 114 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; 115 116 struct xfs_buf_ops { 117 char *name; 118 union { 119 __be32 magic[2]; /* v4 and v5 on disk magic values */ 120 __be16 magic16[2]; /* v4 and v5 on disk magic values */ 121 }; 122 void (*verify_read)(struct xfs_buf *); 123 void (*verify_write)(struct xfs_buf *); 124 xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); 125 }; 126 127 struct xfs_buf { 128 /* 129 * first cacheline holds all the fields needed for an uncontended cache 130 * hit to be fully processed. The semaphore straddles the cacheline 131 * boundary, but the counter and lock sits on the first cacheline, 132 * which is the only bit that is touched if we hit the semaphore 133 * fast-path on locking. 134 */ 135 struct rhash_head b_rhash_head; /* pag buffer hash node */ 136 137 xfs_daddr_t b_rhash_key; /* buffer cache index */ 138 int b_length; /* size of buffer in BBs */ 139 atomic_t b_hold; /* reference count */ 140 atomic_t b_lru_ref; /* lru reclaim ref count */ 141 xfs_buf_flags_t b_flags; /* status flags */ 142 struct semaphore b_sema; /* semaphore for lockables */ 143 144 /* 145 * concurrent access to b_lru and b_lru_flags are protected by 146 * bt_lru_lock and not by b_sema 147 */ 148 struct list_head b_lru; /* lru list */ 149 spinlock_t b_lock; /* internal state lock */ 150 unsigned int b_state; /* internal state flags */ 151 int b_io_error; /* internal IO error state */ 152 wait_queue_head_t b_waiters; /* unpin waiters */ 153 struct list_head b_list; 154 struct xfs_perag *b_pag; /* contains rbtree root */ 155 struct xfs_mount *b_mount; 156 struct xfs_buftarg *b_target; /* buffer target (device) */ 157 void *b_addr; /* virtual address of buffer */ 158 struct work_struct b_ioend_work; 159 struct completion b_iowait; /* queue for I/O waiters */ 160 struct xfs_buf_log_item *b_log_item; 161 struct list_head b_li_list; /* Log items list head */ 162 struct xfs_trans *b_transp; 163 struct page **b_pages; /* array of page pointers */ 164 struct page *b_page_array[XB_PAGES]; /* inline pages */ 165 struct xfs_buf_map *b_maps; /* compound buffer map */ 166 struct xfs_buf_map __b_map; /* inline compound buffer map */ 167 int b_map_count; 168 atomic_t b_pin_count; /* pin count */ 169 atomic_t b_io_remaining; /* #outstanding I/O requests */ 170 unsigned int b_page_count; /* size of page array */ 171 unsigned int b_offset; /* page offset of b_addr, 172 only for _XBF_KMEM buffers */ 173 int b_error; /* error code on I/O */ 174 175 /* 176 * async write failure retry count. Initialised to zero on the first 177 * failure, then when it exceeds the maximum configured without a 178 * success the write is considered to be failed permanently and the 179 * iodone handler will take appropriate action. 180 * 181 * For retry timeouts, we record the jiffie of the first failure. This 182 * means that we can change the retry timeout for buffers already under 183 * I/O and thus avoid getting stuck in a retry loop with a long timeout. 184 * 185 * last_error is used to ensure that we are getting repeated errors, not 186 * different errors. e.g. a block device might change ENOSPC to EIO when 187 * a failure timeout occurs, so we want to re-initialise the error 188 * retry behaviour appropriately when that happens. 189 */ 190 int b_retries; 191 unsigned long b_first_retry_time; /* in jiffies */ 192 int b_last_error; 193 194 const struct xfs_buf_ops *b_ops; 195 }; 196 197 /* Finding and Reading Buffers */ 198 struct xfs_buf *xfs_buf_incore(struct xfs_buftarg *target, 199 xfs_daddr_t blkno, size_t numblks, 200 xfs_buf_flags_t flags); 201 202 int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 203 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp); 204 int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map, 205 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, 206 const struct xfs_buf_ops *ops, xfs_failaddr_t fa); 207 void xfs_buf_readahead_map(struct xfs_buftarg *target, 208 struct xfs_buf_map *map, int nmaps, 209 const struct xfs_buf_ops *ops); 210 211 static inline int 212 xfs_buf_get( 213 struct xfs_buftarg *target, 214 xfs_daddr_t blkno, 215 size_t numblks, 216 struct xfs_buf **bpp) 217 { 218 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 219 220 return xfs_buf_get_map(target, &map, 1, 0, bpp); 221 } 222 223 static inline int 224 xfs_buf_read( 225 struct xfs_buftarg *target, 226 xfs_daddr_t blkno, 227 size_t numblks, 228 xfs_buf_flags_t flags, 229 struct xfs_buf **bpp, 230 const struct xfs_buf_ops *ops) 231 { 232 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 233 234 return xfs_buf_read_map(target, &map, 1, flags, bpp, ops, 235 __builtin_return_address(0)); 236 } 237 238 static inline void 239 xfs_buf_readahead( 240 struct xfs_buftarg *target, 241 xfs_daddr_t blkno, 242 size_t numblks, 243 const struct xfs_buf_ops *ops) 244 { 245 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); 246 return xfs_buf_readahead_map(target, &map, 1, ops); 247 } 248 249 int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, int flags, 250 struct xfs_buf **bpp); 251 int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, 252 size_t numblks, int flags, struct xfs_buf **bpp, 253 const struct xfs_buf_ops *ops); 254 int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags); 255 void xfs_buf_hold(struct xfs_buf *bp); 256 257 /* Releasing Buffers */ 258 extern void xfs_buf_rele(struct xfs_buf *); 259 260 /* Locking and Unlocking Buffers */ 261 extern int xfs_buf_trylock(struct xfs_buf *); 262 extern void xfs_buf_lock(struct xfs_buf *); 263 extern void xfs_buf_unlock(struct xfs_buf *); 264 #define xfs_buf_islocked(bp) \ 265 ((bp)->b_sema.count <= 0) 266 267 static inline void xfs_buf_relse(struct xfs_buf *bp) 268 { 269 xfs_buf_unlock(bp); 270 xfs_buf_rele(bp); 271 } 272 273 /* Buffer Read and Write Routines */ 274 extern int xfs_bwrite(struct xfs_buf *bp); 275 276 extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, 277 xfs_failaddr_t failaddr); 278 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) 279 extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa); 280 void xfs_buf_ioend_fail(struct xfs_buf *); 281 void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize); 282 void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa); 283 #define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address) 284 285 /* Buffer Utility Routines */ 286 extern void *xfs_buf_offset(struct xfs_buf *, size_t); 287 extern void xfs_buf_stale(struct xfs_buf *bp); 288 289 /* Delayed Write Buffer Routines */ 290 extern void xfs_buf_delwri_cancel(struct list_head *); 291 extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); 292 extern int xfs_buf_delwri_submit(struct list_head *); 293 extern int xfs_buf_delwri_submit_nowait(struct list_head *); 294 extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); 295 296 /* Buffer Daemon Setup Routines */ 297 extern int xfs_buf_init(void); 298 extern void xfs_buf_terminate(void); 299 300 static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) 301 { 302 return bp->b_maps[0].bm_bn; 303 } 304 305 void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); 306 307 /* 308 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer 309 * up with a reference count of 0 so it will be tossed from the cache when 310 * released. 311 */ 312 static inline void xfs_buf_oneshot(struct xfs_buf *bp) 313 { 314 if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1) 315 return; 316 atomic_set(&bp->b_lru_ref, 0); 317 } 318 319 static inline int xfs_buf_ispinned(struct xfs_buf *bp) 320 { 321 return atomic_read(&bp->b_pin_count); 322 } 323 324 static inline int 325 xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 326 { 327 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), 328 cksum_offset); 329 } 330 331 static inline void 332 xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) 333 { 334 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), 335 cksum_offset); 336 } 337 338 /* 339 * Handling of buftargs. 340 */ 341 extern struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *, 342 struct block_device *, struct dax_device *); 343 extern void xfs_free_buftarg(struct xfs_buftarg *); 344 extern void xfs_buftarg_wait(struct xfs_buftarg *); 345 extern void xfs_buftarg_drain(struct xfs_buftarg *); 346 extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int); 347 348 #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) 349 #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) 350 351 int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); 352 bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic); 353 bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic); 354 355 #endif /* __XFS_BUF_H__ */ 356