2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * 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.
14 * 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
21 #include <linux/list.h>
22 #include <linux/types.h>
23 #include <linux/spinlock.h>
26 #include <linux/dax.h>
27 #include <linux/buffer_head.h>
28 #include <linux/uio.h>
29 #include <linux/list_lru.h>
35 #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
38 XBRW_READ
= 1, /* transfer into target memory */
39 XBRW_WRITE
= 2, /* transfer from target memory */
40 XBRW_ZERO
= 3, /* Zero target memory */
43 #define XBF_READ (1 << 0) /* buffer intended for reading from device */
44 #define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
45 #define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
46 #define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
47 #define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
48 #define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */
49 #define XBF_WRITE_FAIL (1 << 24)/* async writes have failed on this buffer */
51 /* I/O hints for the BIO layer */
52 #define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */
53 #define XBF_FUA (1 << 11)/* force cache write through mode */
54 #define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */
56 /* flags used only as arguments to access routines */
57 #define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
58 #define XBF_UNMAPPED (1 << 17)/* do not map the buffer */
60 /* flags used only internally */
61 #define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
62 #define _XBF_KMEM (1 << 21)/* backed by heap memory */
63 #define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */
64 #define _XBF_COMPOUND (1 << 23)/* compound buffer */
66 typedef unsigned int xfs_buf_flags_t
;
68 #define XFS_BUF_FLAGS \
69 { XBF_READ, "READ" }, \
70 { XBF_WRITE, "WRITE" }, \
71 { XBF_READ_AHEAD, "READ_AHEAD" }, \
72 { XBF_ASYNC, "ASYNC" }, \
73 { XBF_DONE, "DONE" }, \
74 { XBF_STALE, "STALE" }, \
75 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \
76 { XBF_SYNCIO, "SYNCIO" }, \
78 { XBF_FLUSH, "FLUSH" }, \
79 { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\
80 { XBF_UNMAPPED, "UNMAPPED" }, /* ditto */\
81 { _XBF_PAGES, "PAGES" }, \
82 { _XBF_KMEM, "KMEM" }, \
83 { _XBF_DELWRI_Q, "DELWRI_Q" }, \
84 { _XBF_COMPOUND, "COMPOUND" }
88 * Internal state flags.
90 #define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */
93 * The xfs_buftarg contains 2 notions of "sector size" -
95 * 1) The metadata sector size, which is the minimum unit and
96 * alignment of IO which will be performed by metadata operations.
97 * 2) The device logical sector size
99 * The first is specified at mkfs time, and is stored on-disk in the
100 * superblock's sb_sectsize.
102 * The latter is derived from the underlying device, and controls direct IO
103 * alignment constraints.
105 typedef struct xfs_buftarg
{
107 struct block_device
*bt_bdev
;
108 struct backing_dev_info
*bt_bdi
;
109 struct xfs_mount
*bt_mount
;
110 unsigned int bt_meta_sectorsize
;
111 size_t bt_meta_sectormask
;
112 size_t bt_logical_sectorsize
;
113 size_t bt_logical_sectormask
;
115 /* LRU control structures */
116 struct shrinker bt_shrinker
;
117 struct list_lru bt_lru
;
121 typedef void (*xfs_buf_iodone_t
)(struct xfs_buf
*);
127 xfs_daddr_t bm_bn
; /* block number for I/O */
128 int bm_len
; /* size of I/O */
131 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
132 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
136 void (*verify_read
)(struct xfs_buf
*);
137 void (*verify_write
)(struct xfs_buf
*);
140 typedef struct xfs_buf
{
142 * first cacheline holds all the fields needed for an uncontended cache
143 * hit to be fully processed. The semaphore straddles the cacheline
144 * boundary, but the counter and lock sits on the first cacheline,
145 * which is the only bit that is touched if we hit the semaphore
146 * fast-path on locking.
148 struct rb_node b_rbnode
; /* rbtree node */
149 xfs_daddr_t b_bn
; /* block number of buffer */
150 int b_length
; /* size of buffer in BBs */
151 atomic_t b_hold
; /* reference count */
152 atomic_t b_lru_ref
; /* lru reclaim ref count */
153 xfs_buf_flags_t b_flags
; /* status flags */
154 struct semaphore b_sema
; /* semaphore for lockables */
157 * concurrent access to b_lru and b_lru_flags are protected by
158 * bt_lru_lock and not by b_sema
160 struct list_head b_lru
; /* lru list */
161 spinlock_t b_lock
; /* internal state lock */
162 unsigned int b_state
; /* internal state flags */
163 int b_io_error
; /* internal IO error state */
164 wait_queue_head_t b_waiters
; /* unpin waiters */
165 struct list_head b_list
;
166 struct xfs_perag
*b_pag
; /* contains rbtree root */
167 xfs_buftarg_t
*b_target
; /* buffer target (device) */
168 void *b_addr
; /* virtual address of buffer */
169 struct work_struct b_ioend_work
;
170 struct workqueue_struct
*b_ioend_wq
; /* I/O completion wq */
171 xfs_buf_iodone_t b_iodone
; /* I/O completion function */
172 struct completion b_iowait
; /* queue for I/O waiters */
174 struct xfs_trans
*b_transp
;
175 struct page
**b_pages
; /* array of page pointers */
176 struct page
*b_page_array
[XB_PAGES
]; /* inline pages */
177 struct xfs_buf_map
*b_maps
; /* compound buffer map */
178 struct xfs_buf_map __b_map
; /* inline compound buffer map */
180 int b_io_length
; /* IO size in BBs */
181 atomic_t b_pin_count
; /* pin count */
182 atomic_t b_io_remaining
; /* #outstanding I/O requests */
183 unsigned int b_page_count
; /* size of page array */
184 unsigned int b_offset
; /* page offset in first page */
185 int b_error
; /* error code on I/O */
186 const struct xfs_buf_ops
*b_ops
;
188 #ifdef XFS_BUF_LOCK_TRACKING
193 /* Finding and Reading Buffers */
194 struct xfs_buf
*_xfs_buf_find(struct xfs_buftarg
*target
,
195 struct xfs_buf_map
*map
, int nmaps
,
196 xfs_buf_flags_t flags
, struct xfs_buf
*new_bp
);
198 static inline struct xfs_buf
*
200 struct xfs_buftarg
*target
,
203 xfs_buf_flags_t flags
)
205 DEFINE_SINGLE_BUF_MAP(map
, blkno
, numblks
);
206 return _xfs_buf_find(target
, &map
, 1, flags
, NULL
);
209 struct xfs_buf
*_xfs_buf_alloc(struct xfs_buftarg
*target
,
210 struct xfs_buf_map
*map
, int nmaps
,
211 xfs_buf_flags_t flags
);
213 static inline struct xfs_buf
*
215 struct xfs_buftarg
*target
,
218 xfs_buf_flags_t flags
)
220 DEFINE_SINGLE_BUF_MAP(map
, blkno
, numblks
);
221 return _xfs_buf_alloc(target
, &map
, 1, flags
);
224 struct xfs_buf
*xfs_buf_get_map(struct xfs_buftarg
*target
,
225 struct xfs_buf_map
*map
, int nmaps
,
226 xfs_buf_flags_t flags
);
227 struct xfs_buf
*xfs_buf_read_map(struct xfs_buftarg
*target
,
228 struct xfs_buf_map
*map
, int nmaps
,
229 xfs_buf_flags_t flags
,
230 const struct xfs_buf_ops
*ops
);
231 void xfs_buf_readahead_map(struct xfs_buftarg
*target
,
232 struct xfs_buf_map
*map
, int nmaps
,
233 const struct xfs_buf_ops
*ops
);
235 static inline struct xfs_buf
*
237 struct xfs_buftarg
*target
,
240 xfs_buf_flags_t flags
)
242 DEFINE_SINGLE_BUF_MAP(map
, blkno
, numblks
);
243 return xfs_buf_get_map(target
, &map
, 1, flags
);
246 static inline struct xfs_buf
*
248 struct xfs_buftarg
*target
,
251 xfs_buf_flags_t flags
,
252 const struct xfs_buf_ops
*ops
)
254 DEFINE_SINGLE_BUF_MAP(map
, blkno
, numblks
);
255 return xfs_buf_read_map(target
, &map
, 1, flags
, ops
);
260 struct xfs_buftarg
*target
,
263 const struct xfs_buf_ops
*ops
)
265 DEFINE_SINGLE_BUF_MAP(map
, blkno
, numblks
);
266 return xfs_buf_readahead_map(target
, &map
, 1, ops
);
269 struct xfs_buf
*xfs_buf_get_empty(struct xfs_buftarg
*target
, size_t numblks
);
270 void xfs_buf_set_empty(struct xfs_buf
*bp
, size_t numblks
);
271 int xfs_buf_associate_memory(struct xfs_buf
*bp
, void *mem
, size_t length
);
273 struct xfs_buf
*xfs_buf_get_uncached(struct xfs_buftarg
*target
, size_t numblks
,
275 int xfs_buf_read_uncached(struct xfs_buftarg
*target
, xfs_daddr_t daddr
,
276 size_t numblks
, int flags
, struct xfs_buf
**bpp
,
277 const struct xfs_buf_ops
*ops
);
278 void xfs_buf_hold(struct xfs_buf
*bp
);
280 /* Releasing Buffers */
281 extern void xfs_buf_free(xfs_buf_t
*);
282 extern void xfs_buf_rele(xfs_buf_t
*);
284 /* Locking and Unlocking Buffers */
285 extern int xfs_buf_trylock(xfs_buf_t
*);
286 extern void xfs_buf_lock(xfs_buf_t
*);
287 extern void xfs_buf_unlock(xfs_buf_t
*);
288 #define xfs_buf_islocked(bp) \
289 ((bp)->b_sema.count <= 0)
291 /* Buffer Read and Write Routines */
292 extern int xfs_bwrite(struct xfs_buf
*bp
);
293 extern void xfs_buf_ioend(struct xfs_buf
*bp
);
294 extern void xfs_buf_ioerror(xfs_buf_t
*, int);
295 extern void xfs_buf_ioerror_alert(struct xfs_buf
*, const char *func
);
296 extern void xfs_buf_submit(struct xfs_buf
*bp
);
297 extern int xfs_buf_submit_wait(struct xfs_buf
*bp
);
298 extern void xfs_buf_iomove(xfs_buf_t
*, size_t, size_t, void *,
300 #define xfs_buf_zero(bp, off, len) \
301 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
303 /* Buffer Utility Routines */
304 extern void *xfs_buf_offset(struct xfs_buf
*, size_t);
306 /* Delayed Write Buffer Routines */
307 extern bool xfs_buf_delwri_queue(struct xfs_buf
*, struct list_head
*);
308 extern int xfs_buf_delwri_submit(struct list_head
*);
309 extern int xfs_buf_delwri_submit_nowait(struct list_head
*);
311 /* Buffer Daemon Setup Routines */
312 extern int xfs_buf_init(void);
313 extern void xfs_buf_terminate(void);
315 #define XFS_BUF_ZEROFLAGS(bp) \
316 ((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC| \
317 XBF_SYNCIO|XBF_FUA|XBF_FLUSH| \
320 void xfs_buf_stale(struct xfs_buf
*bp
);
321 #define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XBF_STALE)
322 #define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XBF_STALE)
324 #define XFS_BUF_DONE(bp) ((bp)->b_flags |= XBF_DONE)
325 #define XFS_BUF_UNDONE(bp) ((bp)->b_flags &= ~XBF_DONE)
326 #define XFS_BUF_ISDONE(bp) ((bp)->b_flags & XBF_DONE)
328 #define XFS_BUF_ASYNC(bp) ((bp)->b_flags |= XBF_ASYNC)
329 #define XFS_BUF_UNASYNC(bp) ((bp)->b_flags &= ~XBF_ASYNC)
330 #define XFS_BUF_ISASYNC(bp) ((bp)->b_flags & XBF_ASYNC)
332 #define XFS_BUF_READ(bp) ((bp)->b_flags |= XBF_READ)
333 #define XFS_BUF_UNREAD(bp) ((bp)->b_flags &= ~XBF_READ)
334 #define XFS_BUF_ISREAD(bp) ((bp)->b_flags & XBF_READ)
336 #define XFS_BUF_WRITE(bp) ((bp)->b_flags |= XBF_WRITE)
337 #define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE)
338 #define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE)
341 * These macros use the IO block map rather than b_bn. b_bn is now really
342 * just for the buffer cache index for cached buffers. As IO does not use b_bn
343 * anymore, uncached buffers do not use b_bn at all and hence must modify the IO
344 * map directly. Uncached buffers are not allowed to be discontiguous, so this
347 * In future, uncached buffers will pass the block number directly to the io
348 * request function and hence these macros will go away at that point.
350 #define XFS_BUF_ADDR(bp) ((bp)->b_maps[0].bm_bn)
351 #define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno))
353 static inline void xfs_buf_set_ref(struct xfs_buf
*bp
, int lru_ref
)
355 atomic_set(&bp
->b_lru_ref
, lru_ref
);
358 static inline int xfs_buf_ispinned(struct xfs_buf
*bp
)
360 return atomic_read(&bp
->b_pin_count
);
363 static inline void xfs_buf_relse(xfs_buf_t
*bp
)
370 xfs_buf_verify_cksum(struct xfs_buf
*bp
, unsigned long cksum_offset
)
372 return xfs_verify_cksum(bp
->b_addr
, BBTOB(bp
->b_length
),
377 xfs_buf_update_cksum(struct xfs_buf
*bp
, unsigned long cksum_offset
)
379 xfs_update_cksum(bp
->b_addr
, BBTOB(bp
->b_length
),
384 * Handling of buftargs.
386 extern xfs_buftarg_t
*xfs_alloc_buftarg(struct xfs_mount
*,
387 struct block_device
*);
388 extern void xfs_free_buftarg(struct xfs_mount
*, struct xfs_buftarg
*);
389 extern void xfs_wait_buftarg(xfs_buftarg_t
*);
390 extern int xfs_setsize_buftarg(xfs_buftarg_t
*, unsigned int);
392 #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
393 #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
395 #endif /* __XFS_BUF_H__ */