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1// SPDX-License-Identifier: GPL-2.02/*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 18extern struct kmem_cache *xfs_buf_cache;19 20/*21 * Base types22 */23struct 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/*48 * Online fsck is scanning the buffer cache for live buffers. Do not warn49 * about length mismatches during lookups and do not return stale buffers.50 */51#define XBF_LIVESCAN (1u << 28)52#define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */53#define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */54#define XBF_UNMAPPED (1u << 31)/* do not map the buffer */55 56 57typedef unsigned int xfs_buf_flags_t;58 59#define XFS_BUF_FLAGS \60 { XBF_READ, "READ" }, \61 { XBF_WRITE, "WRITE" }, \62 { XBF_READ_AHEAD, "READ_AHEAD" }, \63 { XBF_NO_IOACCT, "NO_IOACCT" }, \64 { XBF_ASYNC, "ASYNC" }, \65 { XBF_DONE, "DONE" }, \66 { XBF_STALE, "STALE" }, \67 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \68 { _XBF_INODES, "INODES" }, \69 { _XBF_DQUOTS, "DQUOTS" }, \70 { _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \71 { _XBF_PAGES, "PAGES" }, \72 { _XBF_KMEM, "KMEM" }, \73 { _XBF_DELWRI_Q, "DELWRI_Q" }, \74 /* The following interface flags should never be set */ \75 { XBF_LIVESCAN, "LIVESCAN" }, \76 { XBF_INCORE, "INCORE" }, \77 { XBF_TRYLOCK, "TRYLOCK" }, \78 { XBF_UNMAPPED, "UNMAPPED" }79 80/*81 * Internal state flags.82 */83#define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */84#define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */85 86struct xfs_buf_cache {87 spinlock_t bc_lock;88 struct rhashtable bc_hash;89};90 91int xfs_buf_cache_init(struct xfs_buf_cache *bch);92void xfs_buf_cache_destroy(struct xfs_buf_cache *bch);93 94/*95 * The xfs_buftarg contains 2 notions of "sector size" -96 *97 * 1) The metadata sector size, which is the minimum unit and98 * alignment of IO which will be performed by metadata operations.99 * 2) The device logical sector size100 *101 * The first is specified at mkfs time, and is stored on-disk in the102 * superblock's sb_sectsize.103 *104 * The latter is derived from the underlying device, and controls direct IO105 * alignment constraints.106 */107struct xfs_buftarg {108 dev_t bt_dev;109 struct file *bt_bdev_file;110 struct block_device *bt_bdev;111 struct dax_device *bt_daxdev;112 struct file *bt_file;113 u64 bt_dax_part_off;114 struct xfs_mount *bt_mount;115 unsigned int bt_meta_sectorsize;116 size_t bt_meta_sectormask;117 size_t bt_logical_sectorsize;118 size_t bt_logical_sectormask;119 120 /* LRU control structures */121 struct shrinker *bt_shrinker;122 struct list_lru bt_lru;123 124 struct percpu_counter bt_io_count;125 struct ratelimit_state bt_ioerror_rl;126 127 /* built-in cache, if we're not using the perag one */128 struct xfs_buf_cache bt_cache[];129};130 131#define XB_PAGES 2132 133struct xfs_buf_map {134 xfs_daddr_t bm_bn; /* block number for I/O */135 int bm_len; /* size of I/O */136 unsigned int bm_flags;137};138 139/*140 * Online fsck is scanning the buffer cache for live buffers. Do not warn141 * about length mismatches during lookups and do not return stale buffers.142 */143#define XBM_LIVESCAN (1U << 0)144 145#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \146 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };147 148struct xfs_buf_ops {149 char *name;150 union {151 __be32 magic[2]; /* v4 and v5 on disk magic values */152 __be16 magic16[2]; /* v4 and v5 on disk magic values */153 };154 void (*verify_read)(struct xfs_buf *);155 void (*verify_write)(struct xfs_buf *);156 xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp);157};158 159struct xfs_buf {160 /*161 * first cacheline holds all the fields needed for an uncontended cache162 * hit to be fully processed. The semaphore straddles the cacheline163 * boundary, but the counter and lock sits on the first cacheline,164 * which is the only bit that is touched if we hit the semaphore165 * fast-path on locking.166 */167 struct rhash_head b_rhash_head; /* pag buffer hash node */168 169 xfs_daddr_t b_rhash_key; /* buffer cache index */170 int b_length; /* size of buffer in BBs */171 atomic_t b_hold; /* reference count */172 atomic_t b_lru_ref; /* lru reclaim ref count */173 xfs_buf_flags_t b_flags; /* status flags */174 struct semaphore b_sema; /* semaphore for lockables */175 176 /*177 * concurrent access to b_lru and b_lru_flags are protected by178 * bt_lru_lock and not by b_sema179 */180 struct list_head b_lru; /* lru list */181 spinlock_t b_lock; /* internal state lock */182 unsigned int b_state; /* internal state flags */183 int b_io_error; /* internal IO error state */184 wait_queue_head_t b_waiters; /* unpin waiters */185 struct list_head b_list;186 struct xfs_perag *b_pag; /* contains rbtree root */187 struct xfs_mount *b_mount;188 struct xfs_buftarg *b_target; /* buffer target (device) */189 void *b_addr; /* virtual address of buffer */190 struct work_struct b_ioend_work;191 struct completion b_iowait; /* queue for I/O waiters */192 struct xfs_buf_log_item *b_log_item;193 struct list_head b_li_list; /* Log items list head */194 struct xfs_trans *b_transp;195 struct page **b_pages; /* array of page pointers */196 struct page *b_page_array[XB_PAGES]; /* inline pages */197 struct xfs_buf_map *b_maps; /* compound buffer map */198 struct xfs_buf_map __b_map; /* inline compound buffer map */199 int b_map_count;200 atomic_t b_pin_count; /* pin count */201 atomic_t b_io_remaining; /* #outstanding I/O requests */202 unsigned int b_page_count; /* size of page array */203 unsigned int b_offset; /* page offset of b_addr,204 only for _XBF_KMEM buffers */205 int b_error; /* error code on I/O */206 207 /*208 * async write failure retry count. Initialised to zero on the first209 * failure, then when it exceeds the maximum configured without a210 * success the write is considered to be failed permanently and the211 * iodone handler will take appropriate action.212 *213 * For retry timeouts, we record the jiffy of the first failure. This214 * means that we can change the retry timeout for buffers already under215 * I/O and thus avoid getting stuck in a retry loop with a long timeout.216 *217 * last_error is used to ensure that we are getting repeated errors, not218 * different errors. e.g. a block device might change ENOSPC to EIO when219 * a failure timeout occurs, so we want to re-initialise the error220 * retry behaviour appropriately when that happens.221 */222 int b_retries;223 unsigned long b_first_retry_time; /* in jiffies */224 int b_last_error;225 226 const struct xfs_buf_ops *b_ops;227 struct rcu_head b_rcu;228};229 230/* Finding and Reading Buffers */231int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map,232 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp);233int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map,234 int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp,235 const struct xfs_buf_ops *ops, xfs_failaddr_t fa);236void xfs_buf_readahead_map(struct xfs_buftarg *target,237 struct xfs_buf_map *map, int nmaps,238 const struct xfs_buf_ops *ops);239 240static inline int241xfs_buf_incore(242 struct xfs_buftarg *target,243 xfs_daddr_t blkno,244 size_t numblks,245 xfs_buf_flags_t flags,246 struct xfs_buf **bpp)247{248 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);249 250 return xfs_buf_get_map(target, &map, 1, XBF_INCORE | flags, bpp);251}252 253static inline int254xfs_buf_get(255 struct xfs_buftarg *target,256 xfs_daddr_t blkno,257 size_t numblks,258 struct xfs_buf **bpp)259{260 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);261 262 return xfs_buf_get_map(target, &map, 1, 0, bpp);263}264 265static inline int266xfs_buf_read(267 struct xfs_buftarg *target,268 xfs_daddr_t blkno,269 size_t numblks,270 xfs_buf_flags_t flags,271 struct xfs_buf **bpp,272 const struct xfs_buf_ops *ops)273{274 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);275 276 return xfs_buf_read_map(target, &map, 1, flags, bpp, ops,277 __builtin_return_address(0));278}279 280static inline void281xfs_buf_readahead(282 struct xfs_buftarg *target,283 xfs_daddr_t blkno,284 size_t numblks,285 const struct xfs_buf_ops *ops)286{287 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);288 return xfs_buf_readahead_map(target, &map, 1, ops);289}290 291int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,292 xfs_buf_flags_t flags, struct xfs_buf **bpp);293int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr,294 size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp,295 const struct xfs_buf_ops *ops);296int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags);297void xfs_buf_hold(struct xfs_buf *bp);298 299/* Releasing Buffers */300extern void xfs_buf_rele(struct xfs_buf *);301 302/* Locking and Unlocking Buffers */303extern int xfs_buf_trylock(struct xfs_buf *);304extern void xfs_buf_lock(struct xfs_buf *);305extern void xfs_buf_unlock(struct xfs_buf *);306#define xfs_buf_islocked(bp) \307 ((bp)->b_sema.count <= 0)308 309static inline void xfs_buf_relse(struct xfs_buf *bp)310{311 xfs_buf_unlock(bp);312 xfs_buf_rele(bp);313}314 315/* Buffer Read and Write Routines */316extern int xfs_bwrite(struct xfs_buf *bp);317 318extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,319 xfs_failaddr_t failaddr);320#define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)321extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa);322void xfs_buf_ioend_fail(struct xfs_buf *);323void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize);324void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa);325#define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address)326 327/* Buffer Utility Routines */328extern void *xfs_buf_offset(struct xfs_buf *, size_t);329extern void xfs_buf_stale(struct xfs_buf *bp);330 331/* Delayed Write Buffer Routines */332extern void xfs_buf_delwri_cancel(struct list_head *);333extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *);334void xfs_buf_delwri_queue_here(struct xfs_buf *bp, struct list_head *bl);335extern int xfs_buf_delwri_submit(struct list_head *);336extern int xfs_buf_delwri_submit_nowait(struct list_head *);337extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *);338 339static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp)340{341 return bp->b_maps[0].bm_bn;342}343 344void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref);345 346/*347 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer348 * up with a reference count of 0 so it will be tossed from the cache when349 * released.350 */351static inline void xfs_buf_oneshot(struct xfs_buf *bp)352{353 if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1)354 return;355 atomic_set(&bp->b_lru_ref, 0);356}357 358static inline int xfs_buf_ispinned(struct xfs_buf *bp)359{360 return atomic_read(&bp->b_pin_count);361}362 363static inline int364xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset)365{366 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),367 cksum_offset);368}369 370static inline void371xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)372{373 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),374 cksum_offset);375}376 377/*378 * Handling of buftargs.379 */380struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp,381 struct file *bdev_file);382extern void xfs_free_buftarg(struct xfs_buftarg *);383extern void xfs_buftarg_wait(struct xfs_buftarg *);384extern void xfs_buftarg_drain(struct xfs_buftarg *);385extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int);386 387#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)388#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)389 390int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops);391bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic);392bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic);393 394/* for xfs_buf_mem.c only: */395int xfs_init_buftarg(struct xfs_buftarg *btp, size_t logical_sectorsize,396 const char *descr);397void xfs_destroy_buftarg(struct xfs_buftarg *btp);398 399#endif /* __XFS_BUF_H__ */400