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Diffstat (limited to 'fs/xfs/xfs_buf.h')
| -rw-r--r-- | fs/xfs/xfs_buf.h | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h new file mode 100644 index 000000000..a4729253b --- /dev/null +++ b/fs/xfs/xfs_buf.h @@ -0,0 +1,374 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000-2005 Silicon Graphics, Inc. + * All Rights Reserved. + */ +#ifndef __XFS_BUF_H__ +#define __XFS_BUF_H__ + +#include <linux/list.h> +#include <linux/types.h> +#include <linux/spinlock.h> +#include <linux/mm.h> +#include <linux/fs.h> +#include <linux/dax.h> +#include <linux/uio.h> +#include <linux/list_lru.h> +#include <linux/lockref.h> + +extern struct kmem_cache *xfs_buf_cache; + +/* + * Base types + */ +struct xfs_buf; + +#define XFS_BUF_DADDR_MAX ((xfs_daddr_t) S64_MAX) +#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL)) + +#define XBF_READ (1u << 0) /* buffer intended for reading from device */ +#define XBF_WRITE (1u << 1) /* buffer intended for writing to device */ +#define XBF_READ_AHEAD (1u << 2) /* asynchronous read-ahead */ +#define XBF_ASYNC (1u << 4) /* initiator will not wait for completion */ +#define XBF_DONE (1u << 5) /* all pages in the buffer uptodate */ +#define XBF_STALE (1u << 6) /* buffer has been staled, do not find it */ +#define XBF_WRITE_FAIL (1u << 7) /* async writes have failed on this buffer */ + +/* flags used only internally */ +#define _XBF_KMEM (1u << 21)/* backed by heap memory */ +#define _XBF_DELWRI_Q (1u << 22)/* buffer on a delwri queue */ + +/* flags used only as arguments to access routines */ +/* + * Online fsck is scanning the buffer cache for live buffers. Do not warn + * about length mismatches during lookups and do not return stale buffers. + */ +#define XBF_LIVESCAN (1u << 28) +#define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */ +#define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */ + + +typedef unsigned int xfs_buf_flags_t; + +#define XFS_BUF_FLAGS \ + { XBF_READ, "READ" }, \ + { XBF_WRITE, "WRITE" }, \ + { XBF_READ_AHEAD, "READ_AHEAD" }, \ + { XBF_ASYNC, "ASYNC" }, \ + { XBF_DONE, "DONE" }, \ + { XBF_STALE, "STALE" }, \ + { XBF_WRITE_FAIL, "WRITE_FAIL" }, \ + { _XBF_KMEM, "KMEM" }, \ + { _XBF_DELWRI_Q, "DELWRI_Q" }, \ + /* The following interface flags should never be set */ \ + { XBF_LIVESCAN, "LIVESCAN" }, \ + { XBF_INCORE, "INCORE" }, \ + { XBF_TRYLOCK, "TRYLOCK" } + +/* + * The xfs_buftarg contains 2 notions of "sector size" - + * + * 1) The metadata sector size, which is the minimum unit and + * alignment of IO which will be performed by metadata operations. + * 2) The device logical sector size + * + * The first is specified at mkfs time, and is stored on-disk in the + * superblock's sb_sectsize. + * + * The latter is derived from the underlying device, and controls direct IO + * alignment constraints. + */ +struct xfs_buftarg { + dev_t bt_dev; + struct block_device *bt_bdev; + struct dax_device *bt_daxdev; + struct file *bt_file; + u64 bt_dax_part_off; + struct xfs_mount *bt_mount; + unsigned int bt_meta_sectorsize; + size_t bt_meta_sectormask; + size_t bt_logical_sectorsize; + size_t bt_logical_sectormask; + xfs_daddr_t bt_nr_sectors; + + /* LRU control structures */ + struct shrinker *bt_shrinker; + struct list_lru bt_lru; + + struct percpu_counter bt_readahead_count; + struct ratelimit_state bt_ioerror_rl; + + /* Hardware atomic write unit values, bytes */ + unsigned int bt_awu_min; + unsigned int bt_awu_max; + + struct rhashtable bt_hash; +}; + +struct xfs_buf_map { + xfs_daddr_t bm_bn; /* block number for I/O */ + int bm_len; /* size of I/O */ + unsigned int bm_flags; +}; + +/* + * Online fsck is scanning the buffer cache for live buffers. Do not warn + * about length mismatches during lookups and do not return stale buffers. + */ +#define XBM_LIVESCAN (1U << 0) + +#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ + struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; + +struct xfs_buf_ops { + char *name; + union { + __be32 magic[2]; /* v4 and v5 on disk magic values */ + __be16 magic16[2]; /* v4 and v5 on disk magic values */ + }; + void (*verify_read)(struct xfs_buf *); + void (*verify_write)(struct xfs_buf *); + xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); +}; + +struct xfs_buf { + /* + * first cacheline holds all the fields needed for an uncontended cache + * hit to be fully processed. The semaphore straddles the cacheline + * boundary, but the counter and lock sits on the first cacheline, + * which is the only bit that is touched if we hit the semaphore + * fast-path on locking. + */ + struct rhash_head b_rhash_head; /* pag buffer hash node */ + + xfs_daddr_t b_rhash_key; /* buffer cache index */ + int b_length; /* size of buffer in BBs */ + struct lockref b_lockref; /* refcount + lock */ + atomic_t b_lru_ref; /* lru reclaim ref count */ + xfs_buf_flags_t b_flags; /* status flags */ + struct semaphore b_sema; /* semaphore for lockables */ + + /* + * concurrent access to b_lru and b_lru_flags are protected by + * bt_lru_lock and not by b_sema + */ + struct list_head b_lru; /* lru list */ + wait_queue_head_t b_waiters; /* unpin waiters */ + struct list_head b_list; + struct xfs_perag *b_pag; + struct xfs_mount *b_mount; + struct xfs_buftarg *b_target; /* buffer target (device) */ + void *b_addr; /* virtual address of buffer */ + struct work_struct b_ioend_work; + struct completion b_iowait; /* queue for I/O waiters */ + struct xfs_buf_log_item *b_log_item; + struct list_head b_li_list; /* Log items list head */ + struct xfs_trans *b_transp; + struct xfs_buf_map *b_maps; /* compound buffer map */ + struct xfs_buf_map __b_map; /* inline compound buffer map */ + int b_map_count; + atomic_t b_pin_count; /* pin count */ + int b_error; /* error code on I/O */ + void (*b_iodone)(struct xfs_buf *bp); + + /* + * async write failure retry count. Initialised to zero on the first + * failure, then when it exceeds the maximum configured without a + * success the write is considered to be failed permanently and the + * iodone handler will take appropriate action. + * + * For retry timeouts, we record the jiffy of the first failure. This + * means that we can change the retry timeout for buffers already under + * I/O and thus avoid getting stuck in a retry loop with a long timeout. + * + * last_error is used to ensure that we are getting repeated errors, not + * different errors. e.g. a block device might change ENOSPC to EIO when + * a failure timeout occurs, so we want to re-initialise the error + * retry behaviour appropriately when that happens. + */ + int b_retries; + unsigned long b_first_retry_time; /* in jiffies */ + int b_last_error; + + const struct xfs_buf_ops *b_ops; + struct rcu_head b_rcu; +}; + +/* Finding and Reading Buffers */ +int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map, + int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp); +int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map, + int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, + const struct xfs_buf_ops *ops, xfs_failaddr_t fa); +void xfs_buf_readahead_map(struct xfs_buftarg *target, + struct xfs_buf_map *map, int nmaps, + const struct xfs_buf_ops *ops); + +static inline int +xfs_buf_incore( + struct xfs_buftarg *target, + xfs_daddr_t blkno, + size_t numblks, + xfs_buf_flags_t flags, + struct xfs_buf **bpp) +{ + DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); + + return xfs_buf_get_map(target, &map, 1, XBF_INCORE | flags, bpp); +} + +static inline int +xfs_buf_get( + struct xfs_buftarg *target, + xfs_daddr_t blkno, + size_t numblks, + struct xfs_buf **bpp) +{ + DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); + + return xfs_buf_get_map(target, &map, 1, 0, bpp); +} + +static inline int +xfs_buf_read( + struct xfs_buftarg *target, + xfs_daddr_t blkno, + size_t numblks, + xfs_buf_flags_t flags, + struct xfs_buf **bpp, + const struct xfs_buf_ops *ops) +{ + DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); + + return xfs_buf_read_map(target, &map, 1, flags, bpp, ops, + __builtin_return_address(0)); +} + +static inline void +xfs_buf_readahead( + struct xfs_buftarg *target, + xfs_daddr_t blkno, + size_t numblks, + const struct xfs_buf_ops *ops) +{ + DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); + return xfs_buf_readahead_map(target, &map, 1, ops); +} + +int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, + struct xfs_buf **bpp); +int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, + size_t numblks, struct xfs_buf **bpp, + const struct xfs_buf_ops *ops); +int _xfs_buf_read(struct xfs_buf *bp); +void xfs_buf_hold(struct xfs_buf *bp); + +/* Releasing Buffers */ +extern void xfs_buf_rele(struct xfs_buf *); + +/* Locking and Unlocking Buffers */ +extern int xfs_buf_trylock(struct xfs_buf *); +extern void xfs_buf_lock(struct xfs_buf *); +extern void xfs_buf_unlock(struct xfs_buf *); +#define xfs_buf_islocked(bp) \ + ((bp)->b_sema.count <= 0) + +static inline void xfs_buf_relse(struct xfs_buf *bp) +{ + xfs_buf_unlock(bp); + xfs_buf_rele(bp); +} + +/* Buffer Read and Write Routines */ +extern int xfs_bwrite(struct xfs_buf *bp); + +extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, + xfs_failaddr_t failaddr); +#define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) +extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa); +void xfs_buf_fail(struct xfs_buf *bp); +void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa); +#define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address) + +/* Buffer Utility Routines */ +static inline void *xfs_buf_offset(struct xfs_buf *bp, size_t offset) +{ + return bp->b_addr + offset; +} + +static inline void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize) +{ + memset(bp->b_addr + boff, 0, bsize); +} + +void xfs_buf_set_uptodate(struct xfs_buf *bp); +void xfs_buf_stale(struct xfs_buf *bp); +void xfs_buf_clear_stale(struct xfs_buf *bp); + +/* Delayed Write Buffer Routines */ +extern void xfs_buf_delwri_cancel(struct list_head *); +extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); +void xfs_buf_delwri_queue_here(struct xfs_buf *bp, struct list_head *bl); +extern int xfs_buf_delwri_submit(struct list_head *); +extern int xfs_buf_delwri_submit_nowait(struct list_head *); + +static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) +{ + return bp->b_maps[0].bm_bn; +} + +void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); + +/* + * If the buffer is already on the LRU, do nothing. Otherwise set the buffer + * up with a reference count of 0 so it will be tossed from the cache when + * released. + */ +static inline void xfs_buf_oneshot(struct xfs_buf *bp) +{ + if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1) + return; + atomic_set(&bp->b_lru_ref, 0); +} + +static inline int xfs_buf_ispinned(struct xfs_buf *bp) +{ + return atomic_read(&bp->b_pin_count); +} + +static inline int +xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) +{ + return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), + cksum_offset); +} + +static inline void +xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) +{ + xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), + cksum_offset); +} + +/* + * Handling of buftargs. + */ +struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp, + struct file *bdev_file); +extern void xfs_free_buftarg(struct xfs_buftarg *); +extern void xfs_buftarg_wait(struct xfs_buftarg *); +extern void xfs_buftarg_drain(struct xfs_buftarg *); +int xfs_configure_buftarg(struct xfs_buftarg *btp, unsigned int sectorsize, + xfs_fsblock_t nr_blocks); + +#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) + +bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic); +bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic); + +/* for xfs_buf_mem.c only: */ +int xfs_init_buftarg(struct xfs_buftarg *btp, size_t logical_sectorsize, + const char *descr); +void xfs_destroy_buftarg(struct xfs_buftarg *btp); + +#endif /* __XFS_BUF_H__ */ |