1 /*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
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.
8 *
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.
13 *
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
17 */
18 #ifndef __XFS_BUF_H__
19 #define __XFS_BUF_H__
20
21 #include <linux/list.h>
22 #include <linux/types.h>
23 #include <linux/spinlock.h>
24 #include <asm/system.h>
25 #include <linux/mm.h>
26 #include <linux/fs.h>
27 #include <linux/buffer_head.h>
28 #include <linux/uio.h>
29
30 /*
31 * Base types
32 */
33
34 #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
35
36 #define xfs_buf_ctob(pp) ((pp) * PAGE_CACHE_SIZE)
37 #define xfs_buf_btoc(dd) (((dd) + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT)
38 #define xfs_buf_btoct(dd) ((dd) >> PAGE_CACHE_SHIFT)
39 #define xfs_buf_poff(aa) ((aa) & ~PAGE_CACHE_MASK)
40
41 typedef enum {
42 XBRW_READ = 1, /* transfer into target memory */
43 XBRW_WRITE = 2, /* transfer from target memory */
44 XBRW_ZERO = 3, /* Zero target memory */
45 } xfs_buf_rw_t;
46
47 #define XBF_READ (1 << 0) /* buffer intended for reading from device */
48 #define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
49 #define XBF_MAPPED (1 << 2) /* buffer mapped (b_addr valid) */
50 #define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
51 #define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
52 #define XBF_DELWRI (1 << 6) /* buffer has dirty pages */
53 #define XBF_STALE (1 << 7) /* buffer has been staled, do not find it */
54 #define XBF_ORDERED (1 << 11)/* use ordered writes */
55 #define XBF_READ_AHEAD (1 << 12)/* asynchronous read-ahead */
56 #define XBF_LOG_BUFFER (1 << 13)/* this is a buffer used for the log */
57
58 /* flags used only as arguments to access routines */
59 #define XBF_LOCK (1 << 14)/* lock requested */
60 #define XBF_TRYLOCK (1 << 15)/* lock requested, but do not wait */
61 #define XBF_DONT_BLOCK (1 << 16)/* do not block in current thread */
62
63 /* flags used only internally */
64 #define _XBF_PAGES (1 << 18)/* backed by refcounted pages */
65 #define _XBF_RUN_QUEUES (1 << 19)/* run block device task queue */
66 #define _XBF_KMEM (1 << 20)/* backed by heap memory */
67 #define _XBF_DELWRI_Q (1 << 21)/* buffer on delwri queue */
68
69 typedef unsigned int xfs_buf_flags_t;
70
71 #define XFS_BUF_FLAGS \
72 { XBF_READ, "READ" }, \
73 { XBF_WRITE, "WRITE" }, \
74 { XBF_MAPPED, "MAPPED" }, \
75 { XBF_ASYNC, "ASYNC" }, \
76 { XBF_DONE, "DONE" }, \
77 { XBF_DELWRI, "DELWRI" }, \
78 { XBF_STALE, "STALE" }, \
79 { XBF_ORDERED, "ORDERED" }, \
80 { XBF_READ_AHEAD, "READ_AHEAD" }, \
81 { XBF_LOCK, "LOCK" }, /* should never be set */\
82 { XBF_TRYLOCK, "TRYLOCK" }, /* ditto */\
83 { XBF_DONT_BLOCK, "DONT_BLOCK" }, /* ditto */\
84 { _XBF_PAGES, "PAGES" }, \
85 { _XBF_RUN_QUEUES, "RUN_QUEUES" }, \
86 { _XBF_KMEM, "KMEM" }, \
87 { _XBF_DELWRI_Q, "DELWRI_Q" }
88
89 typedef enum {
90 XBT_FORCE_SLEEP = 0,
91 XBT_FORCE_FLUSH = 1,
92 } xfs_buftarg_flags_t;
93
94 typedef struct xfs_bufhash {
95 struct list_head bh_list;
96 spinlock_t bh_lock;
97 } xfs_bufhash_t;
98
99 typedef struct xfs_buftarg {
100 dev_t bt_dev;
101 struct block_device *bt_bdev;
102 struct backing_dev_info *bt_bdi;
103 struct xfs_mount *bt_mount;
104 unsigned int bt_bsize;
105 unsigned int bt_sshift;
106 size_t bt_smask;
107
108 /* per device delwri queue */
109 struct task_struct *bt_task;
110 struct list_head bt_delwrite_queue;
111 spinlock_t bt_delwrite_lock;
112 unsigned long bt_flags;
113
114 /* LRU control structures */
115 struct shrinker bt_shrinker;
116 struct list_head bt_lru;
117 spinlock_t bt_lru_lock;
118 unsigned int bt_lru_nr;
119 } xfs_buftarg_t;
120
121 struct xfs_buf;
122 typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
123
124 #define XB_PAGES 2
125
126 typedef struct xfs_buf {
127 /*
128 * first cacheline holds all the fields needed for an uncontended cache
129 * hit to be fully processed. The semaphore straddles the cacheline
130 * boundary, but the counter and lock sits on the first cacheline,
131 * which is the only bit that is touched if we hit the semaphore
132 * fast-path on locking.
133 */
134 struct rb_node b_rbnode; /* rbtree node */
135 xfs_off_t b_file_offset; /* offset in file */
136 size_t b_buffer_length;/* size of buffer in bytes */
137 atomic_t b_hold; /* reference count */
138 atomic_t b_lru_ref; /* lru reclaim ref count */
139 xfs_buf_flags_t b_flags; /* status flags */
140 struct semaphore b_sema; /* semaphore for lockables */
141
142 struct list_head b_lru; /* lru list */
143 wait_queue_head_t b_waiters; /* unpin waiters */
144 struct list_head b_list;
145 struct xfs_perag *b_pag; /* contains rbtree root */
146 xfs_buftarg_t *b_target; /* buffer target (device) */
147 xfs_daddr_t b_bn; /* block number for I/O */
148 size_t b_count_desired;/* desired transfer size */
149 void *b_addr; /* virtual address of buffer */
150 struct work_struct b_iodone_work;
151 xfs_buf_iodone_t b_iodone; /* I/O completion function */
152 struct completion b_iowait; /* queue for I/O waiters */
153 void *b_fspriv;
154 void *b_fspriv2;
155 struct page **b_pages; /* array of page pointers */
156 struct page *b_page_array[XB_PAGES]; /* inline pages */
157 unsigned long b_queuetime; /* time buffer was queued */
158 atomic_t b_pin_count; /* pin count */
159 atomic_t b_io_remaining; /* #outstanding I/O requests */
160 unsigned int b_page_count; /* size of page array */
161 unsigned int b_offset; /* page offset in first page */
162 unsigned short b_error; /* error code on I/O */
163 #ifdef XFS_BUF_LOCK_TRACKING
164 int b_last_holder;
165 #endif
166 } xfs_buf_t;
167
168
169 /* Finding and Reading Buffers */
170 extern xfs_buf_t *_xfs_buf_find(xfs_buftarg_t *, xfs_off_t, size_t,
171 xfs_buf_flags_t, xfs_buf_t *);
172 #define xfs_incore(buftarg,blkno,len,lockit) \
173 _xfs_buf_find(buftarg, blkno ,len, lockit, NULL)
174
175 extern xfs_buf_t *xfs_buf_get(xfs_buftarg_t *, xfs_off_t, size_t,
176 xfs_buf_flags_t);
177 extern xfs_buf_t *xfs_buf_read(xfs_buftarg_t *, xfs_off_t, size_t,
178 xfs_buf_flags_t);
179
180 extern xfs_buf_t *xfs_buf_get_empty(size_t, xfs_buftarg_t *);
181 extern xfs_buf_t *xfs_buf_get_uncached(struct xfs_buftarg *, size_t, int);
182 extern int xfs_buf_associate_memory(xfs_buf_t *, void *, size_t);
183 extern void xfs_buf_hold(xfs_buf_t *);
184 extern void xfs_buf_readahead(xfs_buftarg_t *, xfs_off_t, size_t);
185 struct xfs_buf *xfs_buf_read_uncached(struct xfs_mount *mp,
186 struct xfs_buftarg *target,
187 xfs_daddr_t daddr, size_t length, int flags);
188
189 /* Releasing Buffers */
190 extern void xfs_buf_free(xfs_buf_t *);
191 extern void xfs_buf_rele(xfs_buf_t *);
192
193 /* Locking and Unlocking Buffers */
194 extern int xfs_buf_cond_lock(xfs_buf_t *);
195 extern int xfs_buf_lock_value(xfs_buf_t *);
196 extern void xfs_buf_lock(xfs_buf_t *);
197 extern void xfs_buf_unlock(xfs_buf_t *);
198
199 /* Buffer Read and Write Routines */
200 extern int xfs_bwrite(struct xfs_mount *mp, struct xfs_buf *bp);
201 extern void xfs_bdwrite(void *mp, xfs_buf_t *bp);
202
203 extern void xfsbdstrat(struct xfs_mount *, struct xfs_buf *);
204 extern int xfs_bdstrat_cb(struct xfs_buf *);
205
206 extern void xfs_buf_ioend(xfs_buf_t *, int);
207 extern void xfs_buf_ioerror(xfs_buf_t *, int);
208 extern int xfs_buf_iorequest(xfs_buf_t *);
209 extern int xfs_buf_iowait(xfs_buf_t *);
210 extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
211 xfs_buf_rw_t);
212 #define xfs_buf_zero(bp, off, len) \
213 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
214
xfs_buf_geterror(xfs_buf_t * bp)215 static inline int xfs_buf_geterror(xfs_buf_t *bp)
216 {
217 return bp ? bp->b_error : ENOMEM;
218 }
219
220 /* Buffer Utility Routines */
221 extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t);
222
223 /* Delayed Write Buffer Routines */
224 extern void xfs_buf_delwri_dequeue(xfs_buf_t *);
225 extern void xfs_buf_delwri_promote(xfs_buf_t *);
226
227 /* Buffer Daemon Setup Routines */
228 extern int xfs_buf_init(void);
229 extern void xfs_buf_terminate(void);
230
231 #define xfs_buf_target_name(target) \
232 ({ char __b[BDEVNAME_SIZE]; bdevname((target)->bt_bdev, __b); __b; })
233
234
235 #define XFS_BUF_BFLAGS(bp) ((bp)->b_flags)
236 #define XFS_BUF_ZEROFLAGS(bp) ((bp)->b_flags &= \
237 ~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI|XBF_ORDERED))
238
239 void xfs_buf_stale(struct xfs_buf *bp);
240 #define XFS_BUF_STALE(bp) xfs_buf_stale(bp);
241 #define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XBF_STALE)
242 #define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XBF_STALE)
243 #define XFS_BUF_SUPER_STALE(bp) do { \
244 XFS_BUF_STALE(bp); \
245 xfs_buf_delwri_dequeue(bp); \
246 XFS_BUF_DONE(bp); \
247 } while (0)
248
249 #define XFS_BUF_DELAYWRITE(bp) ((bp)->b_flags |= XBF_DELWRI)
250 #define XFS_BUF_UNDELAYWRITE(bp) xfs_buf_delwri_dequeue(bp)
251 #define XFS_BUF_ISDELAYWRITE(bp) ((bp)->b_flags & XBF_DELWRI)
252
253 #define XFS_BUF_ERROR(bp,no) xfs_buf_ioerror(bp,no)
254 #define XFS_BUF_GETERROR(bp) xfs_buf_geterror(bp)
255 #define XFS_BUF_ISERROR(bp) (xfs_buf_geterror(bp) ? 1 : 0)
256
257 #define XFS_BUF_DONE(bp) ((bp)->b_flags |= XBF_DONE)
258 #define XFS_BUF_UNDONE(bp) ((bp)->b_flags &= ~XBF_DONE)
259 #define XFS_BUF_ISDONE(bp) ((bp)->b_flags & XBF_DONE)
260
261 #define XFS_BUF_BUSY(bp) do { } while (0)
262 #define XFS_BUF_UNBUSY(bp) do { } while (0)
263 #define XFS_BUF_ISBUSY(bp) (1)
264
265 #define XFS_BUF_ASYNC(bp) ((bp)->b_flags |= XBF_ASYNC)
266 #define XFS_BUF_UNASYNC(bp) ((bp)->b_flags &= ~XBF_ASYNC)
267 #define XFS_BUF_ISASYNC(bp) ((bp)->b_flags & XBF_ASYNC)
268
269 #define XFS_BUF_ORDERED(bp) ((bp)->b_flags |= XBF_ORDERED)
270 #define XFS_BUF_UNORDERED(bp) ((bp)->b_flags &= ~XBF_ORDERED)
271 #define XFS_BUF_ISORDERED(bp) ((bp)->b_flags & XBF_ORDERED)
272
273 #define XFS_BUF_HOLD(bp) xfs_buf_hold(bp)
274 #define XFS_BUF_READ(bp) ((bp)->b_flags |= XBF_READ)
275 #define XFS_BUF_UNREAD(bp) ((bp)->b_flags &= ~XBF_READ)
276 #define XFS_BUF_ISREAD(bp) ((bp)->b_flags & XBF_READ)
277
278 #define XFS_BUF_WRITE(bp) ((bp)->b_flags |= XBF_WRITE)
279 #define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE)
280 #define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE)
281
282 #define XFS_BUF_IODONE_FUNC(bp) ((bp)->b_iodone)
283 #define XFS_BUF_SET_IODONE_FUNC(bp, func) ((bp)->b_iodone = (func))
284 #define XFS_BUF_CLR_IODONE_FUNC(bp) ((bp)->b_iodone = NULL)
285
286 #define XFS_BUF_FSPRIVATE(bp, type) ((type)(bp)->b_fspriv)
287 #define XFS_BUF_SET_FSPRIVATE(bp, val) ((bp)->b_fspriv = (void*)(val))
288 #define XFS_BUF_FSPRIVATE2(bp, type) ((type)(bp)->b_fspriv2)
289 #define XFS_BUF_SET_FSPRIVATE2(bp, val) ((bp)->b_fspriv2 = (void*)(val))
290 #define XFS_BUF_SET_START(bp) do { } while (0)
291
292 #define XFS_BUF_PTR(bp) (xfs_caddr_t)((bp)->b_addr)
293 #define XFS_BUF_SET_PTR(bp, val, cnt) xfs_buf_associate_memory(bp, val, cnt)
294 #define XFS_BUF_ADDR(bp) ((bp)->b_bn)
295 #define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_bn = (xfs_daddr_t)(bno))
296 #define XFS_BUF_OFFSET(bp) ((bp)->b_file_offset)
297 #define XFS_BUF_SET_OFFSET(bp, off) ((bp)->b_file_offset = (off))
298 #define XFS_BUF_COUNT(bp) ((bp)->b_count_desired)
299 #define XFS_BUF_SET_COUNT(bp, cnt) ((bp)->b_count_desired = (cnt))
300 #define XFS_BUF_SIZE(bp) ((bp)->b_buffer_length)
301 #define XFS_BUF_SET_SIZE(bp, cnt) ((bp)->b_buffer_length = (cnt))
302
303 static inline void
xfs_buf_set_ref(struct xfs_buf * bp,int lru_ref)304 xfs_buf_set_ref(
305 struct xfs_buf *bp,
306 int lru_ref)
307 {
308 atomic_set(&bp->b_lru_ref, lru_ref);
309 }
310 #define XFS_BUF_SET_VTYPE_REF(bp, type, ref) xfs_buf_set_ref(bp, ref)
311 #define XFS_BUF_SET_VTYPE(bp, type) do { } while (0)
312
313 #define XFS_BUF_ISPINNED(bp) atomic_read(&((bp)->b_pin_count))
314
315 #define XFS_BUF_VALUSEMA(bp) xfs_buf_lock_value(bp)
316 #define XFS_BUF_CPSEMA(bp) (xfs_buf_cond_lock(bp) == 0)
317 #define XFS_BUF_VSEMA(bp) xfs_buf_unlock(bp)
318 #define XFS_BUF_PSEMA(bp,x) xfs_buf_lock(bp)
319 #define XFS_BUF_FINISH_IOWAIT(bp) complete(&bp->b_iowait);
320
321 #define XFS_BUF_SET_TARGET(bp, target) ((bp)->b_target = (target))
322 #define XFS_BUF_TARGET(bp) ((bp)->b_target)
323 #define XFS_BUFTARG_NAME(target) xfs_buf_target_name(target)
324
xfs_buf_relse(xfs_buf_t * bp)325 static inline void xfs_buf_relse(xfs_buf_t *bp)
326 {
327 xfs_buf_unlock(bp);
328 xfs_buf_rele(bp);
329 }
330
331 /*
332 * Handling of buftargs.
333 */
334 extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *,
335 struct block_device *, int, const char *);
336 extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *);
337 extern void xfs_wait_buftarg(xfs_buftarg_t *);
338 extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
339 extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
340
341 #ifdef CONFIG_KDB_MODULES
342 extern struct list_head *xfs_get_buftarg_list(void);
343 #endif
344
345 #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
346 #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
347
348 #define xfs_binval(buftarg) xfs_flush_buftarg(buftarg, 1)
349 #define XFS_bflush(buftarg) xfs_flush_buftarg(buftarg, 1)
350
351 #endif /* __XFS_BUF_H__ */
352