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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Nathan Scott7b718762005-11-02 14:58:39 +11005 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * published by the Free Software Foundation.
8 *
Nathan Scott7b718762005-11-02 14:58:39 +11009 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Nathan Scott7b718762005-11-02 14:58:39 +110014 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#ifndef __XFS_BUF_H__
19#define __XFS_BUF_H__
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/list.h>
22#include <linux/types.h>
23#include <linux/spinlock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/mm.h>
25#include <linux/fs.h>
26#include <linux/buffer_head.h>
27#include <linux/uio.h>
28
29/*
30 * Base types
31 */
32
Nathan Scottce8e9222006-01-11 15:39:08 +110033#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Nathan Scottce8e9222006-01-11 15:39:08 +110035#define xfs_buf_ctob(pp) ((pp) * PAGE_CACHE_SIZE)
36#define xfs_buf_btoc(dd) (((dd) + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT)
37#define xfs_buf_btoct(dd) ((dd) >> PAGE_CACHE_SHIFT)
38#define xfs_buf_poff(aa) ((aa) & ~PAGE_CACHE_MASK)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Nathan Scottce8e9222006-01-11 15:39:08 +110040typedef enum {
41 XBRW_READ = 1, /* transfer into target memory */
42 XBRW_WRITE = 2, /* transfer from target memory */
43 XBRW_ZERO = 3, /* Zero target memory */
44} xfs_buf_rw_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
Christoph Hellwig807cbbd2010-06-24 11:49:12 +100046#define XBF_READ (1 << 0) /* buffer intended for reading from device */
47#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
Christoph Hellwig1d5ae5d2011-07-08 14:36:32 +020048#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
49#define XBF_MAPPED (1 << 3) /* buffer mapped (b_addr valid) */
Christoph Hellwig807cbbd2010-06-24 11:49:12 +100050#define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
51#define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
Christoph Hellwig43ff2122012-04-23 15:58:39 +100052#define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */
Christoph Hellwig1d5ae5d2011-07-08 14:36:32 +020053
54/* I/O hints for the BIO layer */
55#define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */
56#define XBF_FUA (1 << 11)/* force cache write through mode */
57#define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Christoph Hellwig807cbbd2010-06-24 11:49:12 +100059/* flags used only as arguments to access routines */
Christoph Hellwig1d5ae5d2011-07-08 14:36:32 +020060#define XBF_LOCK (1 << 15)/* lock requested */
61#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
62#define XBF_DONT_BLOCK (1 << 17)/* do not block in current thread */
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Christoph Hellwig807cbbd2010-06-24 11:49:12 +100064/* flags used only internally */
Christoph Hellwig1d5ae5d2011-07-08 14:36:32 +020065#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
66#define _XBF_KMEM (1 << 21)/* backed by heap memory */
Christoph Hellwig43ff2122012-04-23 15:58:39 +100067#define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */
Christoph Hellwig6ab455e2008-05-19 16:34:42 +100068
Christoph Hellwig807cbbd2010-06-24 11:49:12 +100069typedef unsigned int xfs_buf_flags_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000071#define XFS_BUF_FLAGS \
72 { XBF_READ, "READ" }, \
73 { XBF_WRITE, "WRITE" }, \
Christoph Hellwig1d5ae5d2011-07-08 14:36:32 +020074 { XBF_READ_AHEAD, "READ_AHEAD" }, \
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000075 { XBF_MAPPED, "MAPPED" }, \
76 { XBF_ASYNC, "ASYNC" }, \
77 { XBF_DONE, "DONE" }, \
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000078 { XBF_STALE, "STALE" }, \
Christoph Hellwig1d5ae5d2011-07-08 14:36:32 +020079 { XBF_SYNCIO, "SYNCIO" }, \
80 { XBF_FUA, "FUA" }, \
81 { XBF_FLUSH, "FLUSH" }, \
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000082 { XBF_LOCK, "LOCK" }, /* should never be set */\
83 { XBF_TRYLOCK, "TRYLOCK" }, /* ditto */\
84 { XBF_DONT_BLOCK, "DONT_BLOCK" }, /* ditto */\
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000085 { _XBF_PAGES, "PAGES" }, \
Dave Chinner0e6e8472011-03-26 09:16:45 +110086 { _XBF_KMEM, "KMEM" }, \
87 { _XBF_DELWRI_Q, "DELWRI_Q" }
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000088
Linus Torvalds1da177e2005-04-16 15:20:36 -070089typedef struct xfs_buftarg {
Nathan Scottce8e9222006-01-11 15:39:08 +110090 dev_t bt_dev;
91 struct block_device *bt_bdev;
Dave Chinner0e6e8472011-03-26 09:16:45 +110092 struct backing_dev_info *bt_bdi;
Dave Chinnerebad8612010-09-22 10:47:20 +100093 struct xfs_mount *bt_mount;
Nathan Scottce8e9222006-01-11 15:39:08 +110094 unsigned int bt_bsize;
95 unsigned int bt_sshift;
96 size_t bt_smask;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Dave Chinnerff57ab22010-11-30 17:27:57 +110098 /* LRU control structures */
99 struct shrinker bt_shrinker;
Dave Chinner430cbeb2010-12-02 16:30:55 +1100100 struct list_head bt_lru;
101 spinlock_t bt_lru_lock;
102 unsigned int bt_lru_nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103} xfs_buftarg_t;
104
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105struct xfs_buf;
Nathan Scottce8e9222006-01-11 15:39:08 +1100106typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
Nathan Scottce8e9222006-01-11 15:39:08 +1100108#define XB_PAGES 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
110typedef struct xfs_buf {
Dave Chinner50f59e82010-09-24 19:59:15 +1000111 /*
112 * first cacheline holds all the fields needed for an uncontended cache
113 * hit to be fully processed. The semaphore straddles the cacheline
114 * boundary, but the counter and lock sits on the first cacheline,
115 * which is the only bit that is touched if we hit the semaphore
116 * fast-path on locking.
117 */
Dave Chinner74f75a02010-09-24 19:59:04 +1000118 struct rb_node b_rbnode; /* rbtree node */
Nathan Scottce8e9222006-01-11 15:39:08 +1100119 xfs_off_t b_file_offset; /* offset in file */
120 size_t b_buffer_length;/* size of buffer in bytes */
Dave Chinner50f59e82010-09-24 19:59:15 +1000121 atomic_t b_hold; /* reference count */
Dave Chinner430cbeb2010-12-02 16:30:55 +1100122 atomic_t b_lru_ref; /* lru reclaim ref count */
Dave Chinner50f59e82010-09-24 19:59:15 +1000123 xfs_buf_flags_t b_flags; /* status flags */
124 struct semaphore b_sema; /* semaphore for lockables */
125
Dave Chinner430cbeb2010-12-02 16:30:55 +1100126 struct list_head b_lru; /* lru list */
Dave Chinner50f59e82010-09-24 19:59:15 +1000127 wait_queue_head_t b_waiters; /* unpin waiters */
128 struct list_head b_list;
129 struct xfs_perag *b_pag; /* contains rbtree root */
130 xfs_buftarg_t *b_target; /* buffer target (device) */
131 xfs_daddr_t b_bn; /* block number for I/O */
Nathan Scottce8e9222006-01-11 15:39:08 +1100132 size_t b_count_desired;/* desired transfer size */
133 void *b_addr; /* virtual address of buffer */
134 struct work_struct b_iodone_work;
Nathan Scottce8e9222006-01-11 15:39:08 +1100135 xfs_buf_iodone_t b_iodone; /* I/O completion function */
David Chinnerb4dd3302008-08-13 16:36:11 +1000136 struct completion b_iowait; /* queue for I/O waiters */
Nathan Scottce8e9222006-01-11 15:39:08 +1100137 void *b_fspriv;
Christoph Hellwigbf9d9012011-07-13 13:43:49 +0200138 struct xfs_trans *b_transp;
Nathan Scottce8e9222006-01-11 15:39:08 +1100139 struct page **b_pages; /* array of page pointers */
140 struct page *b_page_array[XB_PAGES]; /* inline pages */
Dave Chinner50f59e82010-09-24 19:59:15 +1000141 atomic_t b_pin_count; /* pin count */
142 atomic_t b_io_remaining; /* #outstanding I/O requests */
143 unsigned int b_page_count; /* size of page array */
144 unsigned int b_offset; /* page offset in first page */
145 unsigned short b_error; /* error code on I/O */
Nathan Scottce8e9222006-01-11 15:39:08 +1100146#ifdef XFS_BUF_LOCK_TRACKING
147 int b_last_holder;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148#endif
149} xfs_buf_t;
150
151
152/* Finding and Reading Buffers */
Nathan Scottce8e9222006-01-11 15:39:08 +1100153extern xfs_buf_t *_xfs_buf_find(xfs_buftarg_t *, xfs_off_t, size_t,
154 xfs_buf_flags_t, xfs_buf_t *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155#define xfs_incore(buftarg,blkno,len,lockit) \
Nathan Scottce8e9222006-01-11 15:39:08 +1100156 _xfs_buf_find(buftarg, blkno ,len, lockit, NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Christoph Hellwig6ad112b2009-11-24 18:02:23 +0000158extern xfs_buf_t *xfs_buf_get(xfs_buftarg_t *, xfs_off_t, size_t,
Nathan Scottce8e9222006-01-11 15:39:08 +1100159 xfs_buf_flags_t);
Christoph Hellwig6ad112b2009-11-24 18:02:23 +0000160extern xfs_buf_t *xfs_buf_read(xfs_buftarg_t *, xfs_off_t, size_t,
Nathan Scottce8e9222006-01-11 15:39:08 +1100161 xfs_buf_flags_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
Christoph Hellwig4347b9d2011-10-10 16:52:48 +0000163struct xfs_buf *xfs_buf_alloc(struct xfs_buftarg *, xfs_off_t, size_t,
164 xfs_buf_flags_t);
Dave Chinner44396472011-04-21 09:34:27 +0000165extern void xfs_buf_set_empty(struct xfs_buf *bp, size_t len);
Dave Chinner686865f2010-09-24 20:07:47 +1000166extern xfs_buf_t *xfs_buf_get_uncached(struct xfs_buftarg *, size_t, int);
Nathan Scottce8e9222006-01-11 15:39:08 +1100167extern int xfs_buf_associate_memory(xfs_buf_t *, void *, size_t);
168extern void xfs_buf_hold(xfs_buf_t *);
Christoph Hellwig1a1a3e92010-10-06 18:41:18 +0000169extern void xfs_buf_readahead(xfs_buftarg_t *, xfs_off_t, size_t);
Dave Chinner5adc94c2010-09-24 21:58:31 +1000170struct xfs_buf *xfs_buf_read_uncached(struct xfs_mount *mp,
171 struct xfs_buftarg *target,
172 xfs_daddr_t daddr, size_t length, int flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
174/* Releasing Buffers */
Nathan Scottce8e9222006-01-11 15:39:08 +1100175extern void xfs_buf_free(xfs_buf_t *);
176extern void xfs_buf_rele(xfs_buf_t *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
178/* Locking and Unlocking Buffers */
Christoph Hellwig0c842ad2011-07-08 14:36:19 +0200179extern int xfs_buf_trylock(xfs_buf_t *);
Nathan Scottce8e9222006-01-11 15:39:08 +1100180extern void xfs_buf_lock(xfs_buf_t *);
181extern void xfs_buf_unlock(xfs_buf_t *);
Christoph Hellwig0c842ad2011-07-08 14:36:19 +0200182#define xfs_buf_islocked(bp) \
183 ((bp)->b_sema.count <= 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184
185/* Buffer Read and Write Routines */
Christoph Hellwigc2b006c2011-08-23 08:28:07 +0000186extern int xfs_bwrite(struct xfs_buf *bp);
Christoph Hellwig4e234712010-01-13 22:17:56 +0000187
188extern void xfsbdstrat(struct xfs_mount *, struct xfs_buf *);
189extern int xfs_bdstrat_cb(struct xfs_buf *);
190
Nathan Scottce8e9222006-01-11 15:39:08 +1100191extern void xfs_buf_ioend(xfs_buf_t *, int);
192extern void xfs_buf_ioerror(xfs_buf_t *, int);
Christoph Hellwig901796a2011-10-10 16:52:49 +0000193extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func);
Dave Chinner0e95f192012-04-23 15:58:46 +1000194extern void xfs_buf_iorequest(xfs_buf_t *);
Nathan Scottce8e9222006-01-11 15:39:08 +1100195extern int xfs_buf_iowait(xfs_buf_t *);
Dave Chinnerb9c48642010-01-20 10:47:39 +1100196extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
Nathan Scottce8e9222006-01-11 15:39:08 +1100197 xfs_buf_rw_t);
Christoph Hellwig1a1a3e92010-10-06 18:41:18 +0000198#define xfs_buf_zero(bp, off, len) \
199 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
Nathan Scottce8e9222006-01-11 15:39:08 +1100201static inline int xfs_buf_geterror(xfs_buf_t *bp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202{
Nathan Scottce8e9222006-01-11 15:39:08 +1100203 return bp ? bp->b_error : ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204}
205
206/* Buffer Utility Routines */
Nathan Scottce8e9222006-01-11 15:39:08 +1100207extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209/* Delayed Write Buffer Routines */
Christoph Hellwig43ff2122012-04-23 15:58:39 +1000210extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *);
211extern int xfs_buf_delwri_submit(struct list_head *);
212extern int xfs_buf_delwri_submit_nowait(struct list_head *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214/* Buffer Daemon Setup Routines */
Nathan Scottce8e9222006-01-11 15:39:08 +1100215extern int xfs_buf_init(void);
216extern void xfs_buf_terminate(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
Christoph Hellwig1d5ae5d2011-07-08 14:36:32 +0200218#define XFS_BUF_ZEROFLAGS(bp) \
Christoph Hellwig43ff2122012-04-23 15:58:39 +1000219 ((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC| \
Christoph Hellwig1d5ae5d2011-07-08 14:36:32 +0200220 XBF_SYNCIO|XBF_FUA|XBF_FLUSH))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
Dave Chinner430cbeb2010-12-02 16:30:55 +1100222void xfs_buf_stale(struct xfs_buf *bp);
Christoph Hellwig0cadda12010-01-19 09:56:44 +0000223#define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XBF_STALE)
224#define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XBF_STALE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
Nathan Scottce8e9222006-01-11 15:39:08 +1100226#define XFS_BUF_DONE(bp) ((bp)->b_flags |= XBF_DONE)
227#define XFS_BUF_UNDONE(bp) ((bp)->b_flags &= ~XBF_DONE)
228#define XFS_BUF_ISDONE(bp) ((bp)->b_flags & XBF_DONE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Nathan Scottce8e9222006-01-11 15:39:08 +1100230#define XFS_BUF_ASYNC(bp) ((bp)->b_flags |= XBF_ASYNC)
231#define XFS_BUF_UNASYNC(bp) ((bp)->b_flags &= ~XBF_ASYNC)
232#define XFS_BUF_ISASYNC(bp) ((bp)->b_flags & XBF_ASYNC)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
Nathan Scottce8e9222006-01-11 15:39:08 +1100234#define XFS_BUF_READ(bp) ((bp)->b_flags |= XBF_READ)
235#define XFS_BUF_UNREAD(bp) ((bp)->b_flags &= ~XBF_READ)
236#define XFS_BUF_ISREAD(bp) ((bp)->b_flags & XBF_READ)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
Nathan Scottce8e9222006-01-11 15:39:08 +1100238#define XFS_BUF_WRITE(bp) ((bp)->b_flags |= XBF_WRITE)
239#define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE)
240#define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
Nathan Scottce8e9222006-01-11 15:39:08 +1100242#define XFS_BUF_ADDR(bp) ((bp)->b_bn)
243#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_bn = (xfs_daddr_t)(bno))
244#define XFS_BUF_OFFSET(bp) ((bp)->b_file_offset)
245#define XFS_BUF_SET_OFFSET(bp, off) ((bp)->b_file_offset = (off))
246#define XFS_BUF_COUNT(bp) ((bp)->b_count_desired)
247#define XFS_BUF_SET_COUNT(bp, cnt) ((bp)->b_count_desired = (cnt))
248#define XFS_BUF_SIZE(bp) ((bp)->b_buffer_length)
249#define XFS_BUF_SET_SIZE(bp, cnt) ((bp)->b_buffer_length = (cnt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
Christoph Hellwig38f23232011-10-10 16:52:45 +0000251static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
Dave Chinner821eb212010-12-02 16:31:13 +1100252{
253 atomic_set(&bp->b_lru_ref, lru_ref);
254}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
Chandra Seetharaman811e64c2011-07-22 23:40:27 +0000256static inline int xfs_buf_ispinned(struct xfs_buf *bp)
257{
258 return atomic_read(&bp->b_pin_count);
259}
Nathan Scottce8e9222006-01-11 15:39:08 +1100260
Nathan Scottce8e9222006-01-11 15:39:08 +1100261static inline void xfs_buf_relse(xfs_buf_t *bp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262{
Christoph Hellwigbfc60172011-01-07 13:02:23 +0000263 xfs_buf_unlock(bp);
Nathan Scottce8e9222006-01-11 15:39:08 +1100264 xfs_buf_rele(bp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267/*
268 * Handling of buftargs.
269 */
Dave Chinnerebad8612010-09-22 10:47:20 +1000270extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *,
271 struct block_device *, int, const char *);
Christoph Hellwigc141b292009-03-03 14:48:37 -0500272extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273extern void xfs_wait_buftarg(xfs_buftarg_t *);
274extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
Dave Chinnerd808f612010-02-02 10:13:42 +1100275
Nathan Scottce8e9222006-01-11 15:39:08 +1100276#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
277#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
278
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279#endif /* __XFS_BUF_H__ */