2 * Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like. Any license provided herein, whether implied or
15 * otherwise, applies only to this software file. Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write the Free Software Foundation, Inc., 59
21 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24 * Mountain View, CA 94043, or:
28 * For further information regarding this notice, see:
30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
34 * Written by Steve Lord, Jim Mostek, Russell Cattelan at SGI
40 #include <linux/config.h>
41 #include <linux/list.h>
42 #include <linux/types.h>
43 #include <linux/spinlock.h>
44 #include <asm/system.h>
47 #include <linux/buffer_head.h>
48 #include <linux/uio.h>
54 #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
56 #define page_buf_ctob(pp) ((pp) * PAGE_CACHE_SIZE)
57 #define page_buf_btoc(dd) (((dd) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT)
58 #define page_buf_btoct(dd) ((dd) >> PAGE_CACHE_SHIFT)
59 #define page_buf_poff(aa) ((aa) & ~PAGE_CACHE_MASK)
61 typedef enum page_buf_rw_e {
62 PBRW_READ = 1, /* transfer into target memory */
63 PBRW_WRITE = 2, /* transfer from target memory */
64 PBRW_ZERO = 3 /* Zero target memory */
68 typedef enum page_buf_flags_e { /* pb_flags values */
69 PBF_READ = (1 << 0), /* buffer intended for reading from device */
70 PBF_WRITE = (1 << 1), /* buffer intended for writing to device */
71 PBF_MAPPED = (1 << 2), /* buffer mapped (pb_addr valid) */
72 PBF_ASYNC = (1 << 4), /* initiator will not wait for completion */
73 PBF_NONE = (1 << 5), /* buffer not read at all */
74 PBF_DELWRI = (1 << 6), /* buffer has dirty pages */
75 PBF_STALE = (1 << 7), /* buffer has been staled, do not find it */
76 PBF_FS_MANAGED = (1 << 8), /* filesystem controls freeing memory */
77 PBF_ORDERED = (1 << 11), /* use ordered writes */
78 PBF_READ_AHEAD = (1 << 12), /* asynchronous read-ahead */
80 /* flags used only as arguments to access routines */
81 PBF_LOCK = (1 << 14), /* lock requested */
82 PBF_TRYLOCK = (1 << 15), /* lock requested, but do not wait */
83 PBF_DONT_BLOCK = (1 << 16), /* do not block in current thread */
85 /* flags used only internally */
86 _PBF_PAGE_CACHE = (1 << 17),/* backed by pagecache */
87 _PBF_KMEM_ALLOC = (1 << 18),/* backed by kmem_alloc() */
88 _PBF_RUN_QUEUES = (1 << 19),/* run block device task queue */
89 _PBF_DELWRI_Q = (1 << 21), /* buffer on delwri queue */
93 typedef struct xfs_bufhash {
94 struct list_head bh_list;
98 typedef struct xfs_buftarg {
100 struct block_device *pbr_bdev;
101 struct address_space *pbr_mapping;
102 unsigned int pbr_bsize;
103 unsigned int pbr_sshift;
106 /* per-device buffer hash table */
109 xfs_bufhash_t *bt_hash;
113 * xfs_buf_t: Buffer structure for page cache-based buffers
115 * This buffer structure is used by the page cache buffer management routines
116 * to refer to an assembly of pages forming a logical buffer. The actual I/O
117 * is performed with buffer_head structures, as required by drivers.
119 * The buffer structure is used on temporary basis only, and discarded when
120 * released. The real data storage is recorded in the page cache. Metadata is
121 * hashed to the block device on which the file system resides.
126 /* call-back function on I/O completion */
127 typedef void (*page_buf_iodone_t)(struct xfs_buf *);
128 /* call-back function on I/O completion */
129 typedef void (*page_buf_relse_t)(struct xfs_buf *);
130 /* pre-write function */
131 typedef int (*page_buf_bdstrat_t)(struct xfs_buf *);
135 typedef struct xfs_buf {
136 struct semaphore pb_sema; /* semaphore for lockables */
137 unsigned long pb_queuetime; /* time buffer was queued */
138 atomic_t pb_pin_count; /* pin count */
139 wait_queue_head_t pb_waiters; /* unpin waiters */
140 struct list_head pb_list;
141 page_buf_flags_t pb_flags; /* status flags */
142 struct list_head pb_hash_list; /* hash table list */
143 xfs_bufhash_t *pb_hash; /* hash table list start */
144 xfs_buftarg_t *pb_target; /* buffer target (device) */
145 atomic_t pb_hold; /* reference count */
146 xfs_daddr_t pb_bn; /* block number for I/O */
147 loff_t pb_file_offset; /* offset in file */
148 size_t pb_buffer_length; /* size of buffer in bytes */
149 size_t pb_count_desired; /* desired transfer size */
150 void *pb_addr; /* virtual address of buffer */
151 struct work_struct pb_iodone_work;
152 atomic_t pb_io_remaining;/* #outstanding I/O requests */
153 page_buf_iodone_t pb_iodone; /* I/O completion function */
154 page_buf_relse_t pb_relse; /* releasing function */
155 page_buf_bdstrat_t pb_strat; /* pre-write function */
156 struct semaphore pb_iodonesema; /* Semaphore for I/O waiters */
160 unsigned short pb_error; /* error code on I/O */
161 unsigned short pb_locked; /* page array is locked */
162 unsigned int pb_page_count; /* size of page array */
163 unsigned int pb_offset; /* page offset in first page */
164 struct page **pb_pages; /* array of page pointers */
165 struct page *pb_page_array[PB_PAGES]; /* inline pages */
166 #ifdef PAGEBUF_LOCK_TRACKING
172 /* Finding and Reading Buffers */
174 extern xfs_buf_t *_pagebuf_find( /* find buffer for block if */
175 /* the block is in memory */
176 xfs_buftarg_t *, /* inode for block */
177 loff_t, /* starting offset of range */
178 size_t, /* length of range */
179 page_buf_flags_t, /* PBF_LOCK */
180 xfs_buf_t *); /* newly allocated buffer */
182 #define xfs_incore(buftarg,blkno,len,lockit) \
183 _pagebuf_find(buftarg, blkno ,len, lockit, NULL)
185 extern xfs_buf_t *xfs_buf_get_flags( /* allocate a buffer */
186 xfs_buftarg_t *, /* inode for buffer */
187 loff_t, /* starting offset of range */
188 size_t, /* length of range */
189 page_buf_flags_t); /* PBF_LOCK, PBF_READ, */
192 #define xfs_buf_get(target, blkno, len, flags) \
193 xfs_buf_get_flags((target), (blkno), (len), PBF_LOCK | PBF_MAPPED)
195 extern xfs_buf_t *xfs_buf_read_flags( /* allocate and read a buffer */
196 xfs_buftarg_t *, /* inode for buffer */
197 loff_t, /* starting offset of range */
198 size_t, /* length of range */
199 page_buf_flags_t); /* PBF_LOCK, PBF_ASYNC */
201 #define xfs_buf_read(target, blkno, len, flags) \
202 xfs_buf_read_flags((target), (blkno), (len), PBF_LOCK | PBF_MAPPED)
204 extern xfs_buf_t *pagebuf_get_empty( /* allocate pagebuf struct with */
205 /* no memory or disk address */
207 xfs_buftarg_t *); /* mount point "fake" inode */
209 extern xfs_buf_t *pagebuf_get_no_daddr(/* allocate pagebuf struct */
210 /* without disk address */
212 xfs_buftarg_t *); /* mount point "fake" inode */
214 extern int pagebuf_associate_memory(
219 extern void pagebuf_hold( /* increment reference count */
220 xfs_buf_t *); /* buffer to hold */
222 extern void pagebuf_readahead( /* read ahead into cache */
223 xfs_buftarg_t *, /* target for buffer (or NULL) */
224 loff_t, /* starting offset of range */
225 size_t, /* length of range */
226 page_buf_flags_t); /* additional read flags */
228 /* Releasing Buffers */
230 extern void pagebuf_free( /* deallocate a buffer */
231 xfs_buf_t *); /* buffer to deallocate */
233 extern void pagebuf_rele( /* release hold on a buffer */
234 xfs_buf_t *); /* buffer to release */
236 /* Locking and Unlocking Buffers */
238 extern int pagebuf_cond_lock( /* lock buffer, if not locked */
239 /* (returns -EBUSY if locked) */
240 xfs_buf_t *); /* buffer to lock */
242 extern int pagebuf_lock_value( /* return count on lock */
243 xfs_buf_t *); /* buffer to check */
245 extern int pagebuf_lock( /* lock buffer */
246 xfs_buf_t *); /* buffer to lock */
248 extern void pagebuf_unlock( /* unlock buffer */
249 xfs_buf_t *); /* buffer to unlock */
251 /* Buffer Read and Write Routines */
253 extern void pagebuf_iodone( /* mark buffer I/O complete */
254 xfs_buf_t *, /* buffer to mark */
255 int); /* run completion locally, or in
256 * a helper thread. */
258 extern void pagebuf_ioerror( /* mark buffer in error (or not) */
259 xfs_buf_t *, /* buffer to mark */
260 int); /* error to store (0 if none) */
262 extern int pagebuf_iostart( /* start I/O on a buffer */
263 xfs_buf_t *, /* buffer to start */
264 page_buf_flags_t); /* PBF_LOCK, PBF_ASYNC, */
265 /* PBF_READ, PBF_WRITE, */
268 extern int pagebuf_iorequest( /* start real I/O */
269 xfs_buf_t *); /* buffer to convey to device */
271 extern int pagebuf_iowait( /* wait for buffer I/O done */
272 xfs_buf_t *); /* buffer to wait on */
274 extern void pagebuf_iomove( /* move data in/out of pagebuf */
275 xfs_buf_t *, /* buffer to manipulate */
276 size_t, /* starting buffer offset */
277 size_t, /* length in buffer */
278 caddr_t, /* data pointer */
279 page_buf_rw_t); /* direction */
281 static inline int pagebuf_iostrategy(xfs_buf_t *pb)
283 return pb->pb_strat ? pb->pb_strat(pb) : pagebuf_iorequest(pb);
286 static inline int pagebuf_geterror(xfs_buf_t *pb)
288 return pb ? pb->pb_error : ENOMEM;
291 /* Buffer Utility Routines */
293 extern caddr_t pagebuf_offset( /* pointer at offset in buffer */
294 xfs_buf_t *, /* buffer to offset into */
295 size_t); /* offset */
297 /* Pinning Buffer Storage in Memory */
299 extern void pagebuf_pin( /* pin buffer in memory */
300 xfs_buf_t *); /* buffer to pin */
302 extern void pagebuf_unpin( /* unpin buffered data */
303 xfs_buf_t *); /* buffer to unpin */
305 extern int pagebuf_ispin( /* check if buffer is pinned */
306 xfs_buf_t *); /* buffer to check */
308 /* Delayed Write Buffer Routines */
310 extern void pagebuf_delwri_dequeue(xfs_buf_t *);
312 /* Buffer Daemon Setup Routines */
314 extern int pagebuf_init(void);
315 extern void pagebuf_terminate(void);
319 extern ktrace_t *pagebuf_trace_buf;
320 extern void pagebuf_trace(
321 xfs_buf_t *, /* buffer being traced */
322 char *, /* description of operation */
323 void *, /* arbitrary diagnostic value */
324 void *); /* return address */
326 # define pagebuf_trace(pb, id, ptr, ra) do { } while (0)
329 #define pagebuf_target_name(target) \
330 ({ char __b[BDEVNAME_SIZE]; bdevname((target)->pbr_bdev, __b); __b; })
334 /* These are just for xfs_syncsub... it sets an internal variable
335 * then passes it to VOP_FLUSH_PAGES or adds the flags to a newly gotten buf_t
337 #define XFS_B_ASYNC PBF_ASYNC
338 #define XFS_B_DELWRI PBF_DELWRI
339 #define XFS_B_READ PBF_READ
340 #define XFS_B_WRITE PBF_WRITE
341 #define XFS_B_STALE PBF_STALE
343 #define XFS_BUF_TRYLOCK PBF_TRYLOCK
344 #define XFS_INCORE_TRYLOCK PBF_TRYLOCK
345 #define XFS_BUF_LOCK PBF_LOCK
346 #define XFS_BUF_MAPPED PBF_MAPPED
348 #define BUF_BUSY PBF_DONT_BLOCK
350 #define XFS_BUF_BFLAGS(x) ((x)->pb_flags)
351 #define XFS_BUF_ZEROFLAGS(x) \
352 ((x)->pb_flags &= ~(PBF_READ|PBF_WRITE|PBF_ASYNC|PBF_DELWRI))
354 #define XFS_BUF_STALE(x) ((x)->pb_flags |= XFS_B_STALE)
355 #define XFS_BUF_UNSTALE(x) ((x)->pb_flags &= ~XFS_B_STALE)
356 #define XFS_BUF_ISSTALE(x) ((x)->pb_flags & XFS_B_STALE)
357 #define XFS_BUF_SUPER_STALE(x) do { \
359 pagebuf_delwri_dequeue(x); \
363 #define XFS_BUF_MANAGE PBF_FS_MANAGED
364 #define XFS_BUF_UNMANAGE(x) ((x)->pb_flags &= ~PBF_FS_MANAGED)
366 #define XFS_BUF_DELAYWRITE(x) ((x)->pb_flags |= PBF_DELWRI)
367 #define XFS_BUF_UNDELAYWRITE(x) pagebuf_delwri_dequeue(x)
368 #define XFS_BUF_ISDELAYWRITE(x) ((x)->pb_flags & PBF_DELWRI)
370 #define XFS_BUF_ERROR(x,no) pagebuf_ioerror(x,no)
371 #define XFS_BUF_GETERROR(x) pagebuf_geterror(x)
372 #define XFS_BUF_ISERROR(x) (pagebuf_geterror(x)?1:0)
374 #define XFS_BUF_DONE(x) ((x)->pb_flags &= ~PBF_NONE)
375 #define XFS_BUF_UNDONE(x) ((x)->pb_flags |= PBF_NONE)
376 #define XFS_BUF_ISDONE(x) (((x)->pb_flags & PBF_NONE) == 0)
378 #define XFS_BUF_BUSY(x) do { } while (0)
379 #define XFS_BUF_UNBUSY(x) do { } while (0)
380 #define XFS_BUF_ISBUSY(x) (1)
382 #define XFS_BUF_ASYNC(x) ((x)->pb_flags |= PBF_ASYNC)
383 #define XFS_BUF_UNASYNC(x) ((x)->pb_flags &= ~PBF_ASYNC)
384 #define XFS_BUF_ISASYNC(x) ((x)->pb_flags & PBF_ASYNC)
386 #define XFS_BUF_ORDERED(x) ((x)->pb_flags |= PBF_ORDERED)
387 #define XFS_BUF_UNORDERED(x) ((x)->pb_flags &= ~PBF_ORDERED)
388 #define XFS_BUF_ISORDERED(x) ((x)->pb_flags & PBF_ORDERED)
390 #define XFS_BUF_SHUT(x) printk("XFS_BUF_SHUT not implemented yet\n")
391 #define XFS_BUF_UNSHUT(x) printk("XFS_BUF_UNSHUT not implemented yet\n")
392 #define XFS_BUF_ISSHUT(x) (0)
394 #define XFS_BUF_HOLD(x) pagebuf_hold(x)
395 #define XFS_BUF_READ(x) ((x)->pb_flags |= PBF_READ)
396 #define XFS_BUF_UNREAD(x) ((x)->pb_flags &= ~PBF_READ)
397 #define XFS_BUF_ISREAD(x) ((x)->pb_flags & PBF_READ)
399 #define XFS_BUF_WRITE(x) ((x)->pb_flags |= PBF_WRITE)
400 #define XFS_BUF_UNWRITE(x) ((x)->pb_flags &= ~PBF_WRITE)
401 #define XFS_BUF_ISWRITE(x) ((x)->pb_flags & PBF_WRITE)
403 #define XFS_BUF_ISUNINITIAL(x) (0)
404 #define XFS_BUF_UNUNINITIAL(x) (0)
406 #define XFS_BUF_BP_ISMAPPED(bp) 1
408 #define XFS_BUF_IODONE_FUNC(buf) (buf)->pb_iodone
409 #define XFS_BUF_SET_IODONE_FUNC(buf, func) \
410 (buf)->pb_iodone = (func)
411 #define XFS_BUF_CLR_IODONE_FUNC(buf) \
412 (buf)->pb_iodone = NULL
413 #define XFS_BUF_SET_BDSTRAT_FUNC(buf, func) \
414 (buf)->pb_strat = (func)
415 #define XFS_BUF_CLR_BDSTRAT_FUNC(buf) \
416 (buf)->pb_strat = NULL
418 #define XFS_BUF_FSPRIVATE(buf, type) \
419 ((type)(buf)->pb_fspriv)
420 #define XFS_BUF_SET_FSPRIVATE(buf, value) \
421 (buf)->pb_fspriv = (void *)(value)
422 #define XFS_BUF_FSPRIVATE2(buf, type) \
423 ((type)(buf)->pb_fspriv2)
424 #define XFS_BUF_SET_FSPRIVATE2(buf, value) \
425 (buf)->pb_fspriv2 = (void *)(value)
426 #define XFS_BUF_FSPRIVATE3(buf, type) \
427 ((type)(buf)->pb_fspriv3)
428 #define XFS_BUF_SET_FSPRIVATE3(buf, value) \
429 (buf)->pb_fspriv3 = (void *)(value)
430 #define XFS_BUF_SET_START(buf)
432 #define XFS_BUF_SET_BRELSE_FUNC(buf, value) \
433 (buf)->pb_relse = (value)
435 #define XFS_BUF_PTR(bp) (xfs_caddr_t)((bp)->pb_addr)
437 static inline xfs_caddr_t xfs_buf_offset(xfs_buf_t *bp, size_t offset)
439 if (bp->pb_flags & PBF_MAPPED)
440 return XFS_BUF_PTR(bp) + offset;
441 return (xfs_caddr_t) pagebuf_offset(bp, offset);
444 #define XFS_BUF_SET_PTR(bp, val, count) \
445 pagebuf_associate_memory(bp, val, count)
446 #define XFS_BUF_ADDR(bp) ((bp)->pb_bn)
447 #define XFS_BUF_SET_ADDR(bp, blk) \
448 ((bp)->pb_bn = (xfs_daddr_t)(blk))
449 #define XFS_BUF_OFFSET(bp) ((bp)->pb_file_offset)
450 #define XFS_BUF_SET_OFFSET(bp, off) \
451 ((bp)->pb_file_offset = (off))
452 #define XFS_BUF_COUNT(bp) ((bp)->pb_count_desired)
453 #define XFS_BUF_SET_COUNT(bp, cnt) \
454 ((bp)->pb_count_desired = (cnt))
455 #define XFS_BUF_SIZE(bp) ((bp)->pb_buffer_length)
456 #define XFS_BUF_SET_SIZE(bp, cnt) \
457 ((bp)->pb_buffer_length = (cnt))
458 #define XFS_BUF_SET_VTYPE_REF(bp, type, ref)
459 #define XFS_BUF_SET_VTYPE(bp, type)
460 #define XFS_BUF_SET_REF(bp, ref)
462 #define XFS_BUF_ISPINNED(bp) pagebuf_ispin(bp)
464 #define XFS_BUF_VALUSEMA(bp) pagebuf_lock_value(bp)
465 #define XFS_BUF_CPSEMA(bp) (pagebuf_cond_lock(bp) == 0)
466 #define XFS_BUF_VSEMA(bp) pagebuf_unlock(bp)
467 #define XFS_BUF_PSEMA(bp,x) pagebuf_lock(bp)
468 #define XFS_BUF_V_IODONESEMA(bp) up(&bp->pb_iodonesema);
470 /* setup the buffer target from a buftarg structure */
471 #define XFS_BUF_SET_TARGET(bp, target) \
472 (bp)->pb_target = (target)
473 #define XFS_BUF_TARGET(bp) ((bp)->pb_target)
474 #define XFS_BUFTARG_NAME(target) \
475 pagebuf_target_name(target)
477 #define XFS_BUF_SET_VTYPE_REF(bp, type, ref)
478 #define XFS_BUF_SET_VTYPE(bp, type)
479 #define XFS_BUF_SET_REF(bp, ref)
481 static inline int xfs_bawrite(void *mp, xfs_buf_t *bp)
484 bp->pb_strat = xfs_bdstrat_cb;
485 pagebuf_delwri_dequeue(bp);
486 return pagebuf_iostart(bp, PBF_WRITE | PBF_ASYNC | _PBF_RUN_QUEUES);
489 static inline void xfs_buf_relse(xfs_buf_t *bp)
496 #define xfs_bpin(bp) pagebuf_pin(bp)
497 #define xfs_bunpin(bp) pagebuf_unpin(bp)
499 #define xfs_buftrace(id, bp) \
500 pagebuf_trace(bp, id, NULL, (void *)__builtin_return_address(0))
502 #define xfs_biodone(pb) \
503 pagebuf_iodone(pb, 0)
505 #define xfs_biomove(pb, off, len, data, rw) \
506 pagebuf_iomove((pb), (off), (len), (data), \
507 ((rw) == XFS_B_WRITE) ? PBRW_WRITE : PBRW_READ)
509 #define xfs_biozero(pb, off, len) \
510 pagebuf_iomove((pb), (off), (len), NULL, PBRW_ZERO)
513 static inline int XFS_bwrite(xfs_buf_t *pb)
515 int iowait = (pb->pb_flags & PBF_ASYNC) == 0;
519 pb->pb_flags |= _PBF_RUN_QUEUES;
521 pagebuf_delwri_dequeue(pb);
522 pagebuf_iostrategy(pb);
524 error = pagebuf_iowait(pb);
530 #define XFS_bdwrite(pb) \
531 pagebuf_iostart(pb, PBF_DELWRI | PBF_ASYNC)
533 static inline int xfs_bdwrite(void *mp, xfs_buf_t *bp)
535 bp->pb_strat = xfs_bdstrat_cb;
538 return pagebuf_iostart(bp, PBF_DELWRI | PBF_ASYNC);
541 #define XFS_bdstrat(bp) pagebuf_iorequest(bp)
543 #define xfs_iowait(pb) pagebuf_iowait(pb)
545 #define xfs_baread(target, rablkno, ralen) \
546 pagebuf_readahead((target), (rablkno), (ralen), PBF_DONT_BLOCK)
548 #define xfs_buf_get_empty(len, target) pagebuf_get_empty((len), (target))
549 #define xfs_buf_get_noaddr(len, target) pagebuf_get_no_daddr((len), (target))
550 #define xfs_buf_free(bp) pagebuf_free(bp)
554 * Handling of buftargs.
557 extern xfs_buftarg_t *xfs_alloc_buftarg(struct block_device *, int);
558 extern void xfs_free_buftarg(xfs_buftarg_t *, int);
559 extern void xfs_wait_buftarg(xfs_buftarg_t *);
560 extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
561 extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
563 #define xfs_getsize_buftarg(buftarg) \
564 block_size((buftarg)->pbr_bdev)
565 #define xfs_readonly_buftarg(buftarg) \
566 bdev_read_only((buftarg)->pbr_bdev)
567 #define xfs_binval(buftarg) \
568 xfs_flush_buftarg(buftarg, 1)
569 #define XFS_bflush(buftarg) \
570 xfs_flush_buftarg(buftarg, 1)
572 #endif /* __XFS_BUF_H__ */