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 * The xfs_buf.c code provides an abstract buffer cache model on top
35 * of the Linux page cache. Cached metadata blocks for a file system
36 * are hashed to the inode for the block device. xfs_buf.c assembles
37 * buffers (xfs_buf_t) on demand to aggregate such cached pages for I/O.
39 * Written by Steve Lord, Jim Mostek, Russell Cattelan
40 * and Rajagopal Ananthanarayanan ("ananth") at SGI.
44 #include <linux/stddef.h>
45 #include <linux/errno.h>
46 #include <linux/slab.h>
47 #include <linux/pagemap.h>
48 #include <linux/init.h>
49 #include <linux/vmalloc.h>
50 #include <linux/bio.h>
51 #include <linux/sysctl.h>
52 #include <linux/proc_fs.h>
53 #include <linux/workqueue.h>
54 #include <linux/suspend.h>
55 #include <linux/percpu.h>
57 #include "xfs_linux.h"
60 #define GFP_READAHEAD (__GFP_NOWARN|__GFP_NORETRY)
67 STATIC kmem_cache_t
*pagebuf_cache
;
68 STATIC kmem_shaker_t pagebuf_shake
;
69 STATIC
int pagebuf_daemon_wakeup(int, unsigned int);
70 STATIC
void pagebuf_delwri_queue(xfs_buf_t
*, int);
71 STATIC
struct workqueue_struct
*pagebuf_logio_workqueue
;
72 STATIC
struct workqueue_struct
*pagebuf_dataio_workqueue
;
86 ktrace_enter(pagebuf_trace_buf
,
88 (void *)(unsigned long)pb
->pb_flags
,
89 (void *)(unsigned long)pb
->pb_hold
.counter
,
90 (void *)(unsigned long)pb
->pb_sema
.count
.counter
,
93 (void *)(unsigned long)((pb
->pb_file_offset
>>32) & 0xffffffff),
94 (void *)(unsigned long)(pb
->pb_file_offset
& 0xffffffff),
95 (void *)(unsigned long)pb
->pb_buffer_length
,
96 NULL
, NULL
, NULL
, NULL
, NULL
);
98 ktrace_t
*pagebuf_trace_buf
;
99 #define PAGEBUF_TRACE_SIZE 4096
100 #define PB_TRACE(pb, id, data) \
101 pagebuf_trace(pb, id, (void *)data, (void *)__builtin_return_address(0))
103 #define PB_TRACE(pb, id, data) do { } while (0)
106 #ifdef PAGEBUF_LOCK_TRACKING
107 # define PB_SET_OWNER(pb) ((pb)->pb_last_holder = current->pid)
108 # define PB_CLEAR_OWNER(pb) ((pb)->pb_last_holder = -1)
109 # define PB_GET_OWNER(pb) ((pb)->pb_last_holder)
111 # define PB_SET_OWNER(pb) do { } while (0)
112 # define PB_CLEAR_OWNER(pb) do { } while (0)
113 # define PB_GET_OWNER(pb) do { } while (0)
117 * Pagebuf allocation / freeing.
120 #define pb_to_gfp(flags) \
121 (((flags) & PBF_READ_AHEAD) ? GFP_READAHEAD : \
122 ((flags) & PBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL)
124 #define pb_to_km(flags) \
125 (((flags) & PBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP)
128 #define pagebuf_allocate(flags) \
129 kmem_zone_alloc(pagebuf_cache, pb_to_km(flags))
130 #define pagebuf_deallocate(pb) \
131 kmem_zone_free(pagebuf_cache, (pb));
138 #define NHASH (1<<NBITS)
141 struct list_head pb_hash
;
142 spinlock_t pb_hash_lock
;
145 STATIC pb_hash_t pbhash
[NHASH
];
146 #define pb_hash(pb) &pbhash[pb->pb_hash_index]
150 struct block_device
*bdev
,
156 base
^= (unsigned long)bdev
/ L1_CACHE_BYTES
;
157 for (bit
= hval
= 0; base
&& bit
< sizeof(base
) * 8; bit
+= NBITS
) {
158 hval
^= (int)base
& (NHASH
-1);
165 * Mapping of multi-page buffers into contiguous virtual space
168 typedef struct a_list
{
173 STATIC a_list_t
*as_free_head
;
174 STATIC
int as_list_len
;
175 STATIC spinlock_t as_lock
= SPIN_LOCK_UNLOCKED
;
178 * Try to batch vunmaps because they are costly.
186 aentry
= kmalloc(sizeof(a_list_t
), GFP_ATOMIC
);
189 aentry
->next
= as_free_head
;
190 aentry
->vm_addr
= addr
;
191 as_free_head
= aentry
;
193 spin_unlock(&as_lock
);
200 purge_addresses(void)
202 a_list_t
*aentry
, *old
;
204 if (as_free_head
== NULL
)
208 aentry
= as_free_head
;
211 spin_unlock(&as_lock
);
213 while ((old
= aentry
) != NULL
) {
214 vunmap(aentry
->vm_addr
);
215 aentry
= aentry
->next
;
221 * Internal pagebuf object manipulation
227 xfs_buftarg_t
*target
,
230 page_buf_flags_t flags
)
233 * We don't want certain flags to appear in pb->pb_flags.
235 flags
&= ~(PBF_LOCK
|PBF_MAPPED
|PBF_DONT_BLOCK
|PBF_READ_AHEAD
);
237 memset(pb
, 0, sizeof(xfs_buf_t
));
238 atomic_set(&pb
->pb_hold
, 1);
239 init_MUTEX_LOCKED(&pb
->pb_iodonesema
);
240 INIT_LIST_HEAD(&pb
->pb_list
);
241 INIT_LIST_HEAD(&pb
->pb_hash_list
);
242 init_MUTEX_LOCKED(&pb
->pb_sema
); /* held, no waiters */
244 pb
->pb_target
= target
;
245 pb
->pb_file_offset
= range_base
;
247 * Set buffer_length and count_desired to the same value initially.
248 * I/O routines should use count_desired, which will be the same in
249 * most cases but may be reset (e.g. XFS recovery).
251 pb
->pb_buffer_length
= pb
->pb_count_desired
= range_length
;
252 pb
->pb_flags
= flags
| PBF_NONE
;
253 pb
->pb_bn
= XFS_BUF_DADDR_NULL
;
254 atomic_set(&pb
->pb_pin_count
, 0);
255 init_waitqueue_head(&pb
->pb_waiters
);
257 XFS_STATS_INC(pb_create
);
258 PB_TRACE(pb
, "initialize", target
);
262 * Allocate a page array capable of holding a specified number
263 * of pages, and point the page buf at it.
269 page_buf_flags_t flags
)
271 /* Make sure that we have a page list */
272 if (pb
->pb_pages
== NULL
) {
273 pb
->pb_offset
= page_buf_poff(pb
->pb_file_offset
);
274 pb
->pb_page_count
= page_count
;
275 if (page_count
<= PB_PAGES
) {
276 pb
->pb_pages
= pb
->pb_page_array
;
278 pb
->pb_pages
= kmem_alloc(sizeof(struct page
*) *
279 page_count
, pb_to_km(flags
));
280 if (pb
->pb_pages
== NULL
)
283 memset(pb
->pb_pages
, 0, sizeof(struct page
*) * page_count
);
289 * Frees pb_pages if it was malloced.
295 if (bp
->pb_pages
!= bp
->pb_page_array
) {
296 kmem_free(bp
->pb_pages
,
297 bp
->pb_page_count
* sizeof(struct page
*));
302 * Releases the specified buffer.
304 * The modification state of any associated pages is left unchanged.
305 * The buffer most not be on any hash - use pagebuf_rele instead for
306 * hashed and refcounted buffers
312 PB_TRACE(bp
, "free", 0);
314 ASSERT(list_empty(&bp
->pb_hash_list
));
316 if (bp
->pb_flags
& _PBF_PAGE_CACHE
) {
319 if ((bp
->pb_flags
& PBF_MAPPED
) && (bp
->pb_page_count
> 1))
320 free_address(bp
->pb_addr
- bp
->pb_offset
);
322 for (i
= 0; i
< bp
->pb_page_count
; i
++)
323 page_cache_release(bp
->pb_pages
[i
]);
324 _pagebuf_free_pages(bp
);
325 } else if (bp
->pb_flags
& _PBF_KMEM_ALLOC
) {
327 * XXX(hch): bp->pb_count_desired might be incorrect (see
328 * pagebuf_associate_memory for details), but fortunately
329 * the Linux version of kmem_free ignores the len argument..
331 kmem_free(bp
->pb_addr
, bp
->pb_count_desired
);
332 _pagebuf_free_pages(bp
);
335 pagebuf_deallocate(bp
);
339 * Finds all pages for buffer in question and builds it's page list.
342 _pagebuf_lookup_pages(
346 struct address_space
*mapping
= bp
->pb_target
->pbr_mapping
;
347 unsigned int sectorshift
= bp
->pb_target
->pbr_sshift
;
348 size_t blocksize
= bp
->pb_target
->pbr_bsize
;
349 size_t size
= bp
->pb_count_desired
;
350 size_t nbytes
, offset
;
351 int gfp_mask
= pb_to_gfp(flags
);
352 unsigned short page_count
, i
;
357 end
= bp
->pb_file_offset
+ bp
->pb_buffer_length
;
358 page_count
= page_buf_btoc(end
) - page_buf_btoct(bp
->pb_file_offset
);
360 error
= _pagebuf_get_pages(bp
, page_count
, flags
);
363 bp
->pb_flags
|= _PBF_PAGE_CACHE
;
365 offset
= bp
->pb_offset
;
366 first
= bp
->pb_file_offset
>> PAGE_CACHE_SHIFT
;
368 for (i
= 0; i
< bp
->pb_page_count
; i
++) {
373 page
= find_or_create_page(mapping
, first
+ i
, gfp_mask
);
374 if (unlikely(page
== NULL
)) {
375 if (flags
& PBF_READ_AHEAD
) {
376 bp
->pb_page_count
= i
;
377 for (i
= 0; i
< bp
->pb_page_count
; i
++)
378 unlock_page(bp
->pb_pages
[i
]);
383 * This could deadlock.
385 * But until all the XFS lowlevel code is revamped to
386 * handle buffer allocation failures we can't do much.
388 if (!(++retries
% 100))
390 "possible deadlock in %s (mode:0x%x)\n",
391 __FUNCTION__
, gfp_mask
);
393 XFS_STATS_INC(pb_page_retries
);
394 pagebuf_daemon_wakeup(0, gfp_mask
);
395 set_current_state(TASK_UNINTERRUPTIBLE
);
396 schedule_timeout(10);
400 XFS_STATS_INC(pb_page_found
);
402 nbytes
= min_t(size_t, size
, PAGE_CACHE_SIZE
- offset
);
405 if (!PageUptodate(page
)) {
407 if (blocksize
== PAGE_CACHE_SIZE
) {
408 if (flags
& PBF_READ
)
410 } else if (!PagePrivate(page
)) {
411 unsigned long j
, range
;
414 * In this case page->private holds a bitmap
415 * of uptodate sectors within the page
417 ASSERT(blocksize
< PAGE_CACHE_SIZE
);
418 range
= (offset
+ nbytes
) >> sectorshift
;
419 for (j
= offset
>> sectorshift
; j
< range
; j
++)
420 if (!test_bit(j
, &page
->private))
427 bp
->pb_pages
[i
] = page
;
431 if (!bp
->pb_locked
) {
432 for (i
= 0; i
< bp
->pb_page_count
; i
++)
433 unlock_page(bp
->pb_pages
[i
]);
437 /* if we have any uptodate pages, mark that in the buffer */
438 bp
->pb_flags
&= ~PBF_NONE
;
440 /* if some pages aren't uptodate, mark that in the buffer */
441 if (page_count
!= bp
->pb_page_count
)
442 bp
->pb_flags
|= PBF_PARTIAL
;
445 PB_TRACE(bp
, "lookup_pages", (long)page_count
);
450 * Map buffer into kernel address-space if nessecary.
457 /* A single page buffer is always mappable */
458 if (bp
->pb_page_count
== 1) {
459 bp
->pb_addr
= page_address(bp
->pb_pages
[0]) + bp
->pb_offset
;
460 bp
->pb_flags
|= PBF_MAPPED
;
461 } else if (flags
& PBF_MAPPED
) {
462 if (as_list_len
> 64)
464 bp
->pb_addr
= vmap(bp
->pb_pages
, bp
->pb_page_count
,
465 VM_MAP
, PAGE_KERNEL
);
466 if (unlikely(bp
->pb_addr
== NULL
))
468 bp
->pb_addr
+= bp
->pb_offset
;
469 bp
->pb_flags
|= PBF_MAPPED
;
476 * Finding and Reading Buffers
482 * Looks up, and creates if absent, a lockable buffer for
483 * a given range of an inode. The buffer is returned
484 * locked. If other overlapping buffers exist, they are
485 * released before the new buffer is created and locked,
486 * which may imply that this call will block until those buffers
487 * are unlocked. No I/O is implied by this call.
490 _pagebuf_find( /* find buffer for block */
491 xfs_buftarg_t
*target
,/* target for block */
492 loff_t ioff
, /* starting offset of range */
493 size_t isize
, /* length of range */
494 page_buf_flags_t flags
, /* PBF_TRYLOCK */
495 xfs_buf_t
*new_pb
)/* newly allocated buffer */
504 range_base
= (ioff
<< BBSHIFT
);
505 range_length
= (isize
<< BBSHIFT
);
507 /* Ensure we never do IOs smaller than the sector size */
508 BUG_ON(range_length
< (1 << target
->pbr_sshift
));
510 /* Ensure we never do IOs that are not sector aligned */
511 BUG_ON(range_base
& (loff_t
)target
->pbr_smask
);
513 hval
= _bhash(target
->pbr_bdev
, range_base
);
516 spin_lock(&h
->pb_hash_lock
);
517 list_for_each_entry_safe(pb
, n
, &h
->pb_hash
, pb_hash_list
) {
518 if (pb
->pb_target
== target
&&
519 pb
->pb_file_offset
== range_base
&&
520 pb
->pb_buffer_length
== range_length
) {
521 /* If we look at something bring it to the
522 * front of the list for next time
524 atomic_inc(&pb
->pb_hold
);
525 list_move(&pb
->pb_hash_list
, &h
->pb_hash
);
532 _pagebuf_initialize(new_pb
, target
, range_base
,
533 range_length
, flags
);
534 new_pb
->pb_hash_index
= hval
;
535 list_add(&new_pb
->pb_hash_list
, &h
->pb_hash
);
537 XFS_STATS_INC(pb_miss_locked
);
540 spin_unlock(&h
->pb_hash_lock
);
544 spin_unlock(&h
->pb_hash_lock
);
546 /* Attempt to get the semaphore without sleeping,
547 * if this does not work then we need to drop the
548 * spinlock and do a hard attempt on the semaphore.
550 not_locked
= down_trylock(&pb
->pb_sema
);
552 if (!(flags
& PBF_TRYLOCK
)) {
553 /* wait for buffer ownership */
554 PB_TRACE(pb
, "get_lock", 0);
556 XFS_STATS_INC(pb_get_locked_waited
);
558 /* We asked for a trylock and failed, no need
559 * to look at file offset and length here, we
560 * know that this pagebuf at least overlaps our
561 * pagebuf and is locked, therefore our buffer
562 * either does not exist, or is this buffer
566 XFS_STATS_INC(pb_busy_locked
);
574 if (pb
->pb_flags
& PBF_STALE
)
575 pb
->pb_flags
&= PBF_MAPPED
;
576 PB_TRACE(pb
, "got_lock", 0);
577 XFS_STATS_INC(pb_get_locked
);
585 * pagebuf_find returns a buffer matching the specified range of
586 * data for the specified target, if any of the relevant blocks
587 * are in memory. The buffer may have unallocated holes, if
588 * some, but not all, of the blocks are in memory. Even where
589 * pages are present in the buffer, not all of every page may be
593 pagebuf_find( /* find buffer for block */
594 /* if the block is in memory */
595 xfs_buftarg_t
*target
,/* target for block */
596 loff_t ioff
, /* starting offset of range */
597 size_t isize
, /* length of range */
598 page_buf_flags_t flags
) /* PBF_TRYLOCK */
600 return _pagebuf_find(target
, ioff
, isize
, flags
, NULL
);
606 * pagebuf_get assembles a buffer covering the specified range.
607 * Some or all of the blocks in the range may be valid. Storage
608 * in memory for all portions of the buffer will be allocated,
609 * although backing storage may not be. If PBF_READ is set in
610 * flags, pagebuf_iostart is called also.
613 pagebuf_get( /* allocate a buffer */
614 xfs_buftarg_t
*target
,/* target for buffer */
615 loff_t ioff
, /* starting offset of range */
616 size_t isize
, /* length of range */
617 page_buf_flags_t flags
) /* PBF_TRYLOCK */
619 xfs_buf_t
*pb
, *new_pb
;
622 new_pb
= pagebuf_allocate(flags
);
623 if (unlikely(!new_pb
))
626 pb
= _pagebuf_find(target
, ioff
, isize
, flags
, new_pb
);
628 error
= _pagebuf_lookup_pages(pb
, flags
);
632 pagebuf_deallocate(new_pb
);
633 if (unlikely(pb
== NULL
))
637 for (i
= 0; i
< pb
->pb_page_count
; i
++)
638 mark_page_accessed(pb
->pb_pages
[i
]);
640 if (!(pb
->pb_flags
& PBF_MAPPED
)) {
641 error
= _pagebuf_map_pages(pb
, flags
);
642 if (unlikely(error
)) {
644 "pagebuf_get: failed to map pages\n");
649 XFS_STATS_INC(pb_get
);
652 * Always fill in the block number now, the mapped cases can do
653 * their own overlay of this later.
656 pb
->pb_count_desired
= pb
->pb_buffer_length
;
658 if (flags
& PBF_READ
) {
659 if (PBF_NOT_DONE(pb
)) {
660 PB_TRACE(pb
, "get_read", (unsigned long)flags
);
661 XFS_STATS_INC(pb_get_read
);
662 pagebuf_iostart(pb
, flags
);
663 } else if (flags
& PBF_ASYNC
) {
664 PB_TRACE(pb
, "get_read_async", (unsigned long)flags
);
666 * Read ahead call which is already satisfied,
671 PB_TRACE(pb
, "get_read_done", (unsigned long)flags
);
672 /* We do not want read in the flags */
673 pb
->pb_flags
&= ~PBF_READ
;
676 PB_TRACE(pb
, "get_write", (unsigned long)flags
);
682 if (flags
& (PBF_LOCK
| PBF_TRYLOCK
))
689 * Create a skeletal pagebuf (no pages associated with it).
693 xfs_buftarg_t
*target
,
696 page_buf_flags_t flags
)
700 pb
= pagebuf_allocate(flags
);
702 _pagebuf_initialize(pb
, target
, ioff
, isize
, flags
);
708 * If we are not low on memory then do the readahead in a deadlock
713 xfs_buftarg_t
*target
,
716 page_buf_flags_t flags
)
718 struct backing_dev_info
*bdi
;
720 bdi
= target
->pbr_mapping
->backing_dev_info
;
721 if (bdi_read_congested(bdi
))
723 if (bdi_write_congested(bdi
))
726 flags
|= (PBF_TRYLOCK
|PBF_READ
|PBF_ASYNC
|PBF_READ_AHEAD
);
727 pagebuf_get(target
, ioff
, isize
, flags
);
733 xfs_buftarg_t
*target
)
737 pb
= pagebuf_allocate(0);
739 _pagebuf_initialize(pb
, target
, 0, len
, 0);
743 static inline struct page
*
747 if (((unsigned long)addr
< VMALLOC_START
) ||
748 ((unsigned long)addr
>= VMALLOC_END
)) {
749 return virt_to_page(addr
);
751 return vmalloc_to_page(addr
);
756 pagebuf_associate_memory(
768 page_count
= PAGE_CACHE_ALIGN(len
) >> PAGE_CACHE_SHIFT
;
769 offset
= (off_t
) mem
- ((off_t
)mem
& PAGE_CACHE_MASK
);
770 if (offset
&& (len
> PAGE_CACHE_SIZE
))
773 /* Free any previous set of page pointers */
775 _pagebuf_free_pages(pb
);
780 rval
= _pagebuf_get_pages(pb
, page_count
, 0);
784 pb
->pb_offset
= offset
;
785 ptr
= (size_t) mem
& PAGE_CACHE_MASK
;
786 end
= PAGE_CACHE_ALIGN((size_t) mem
+ len
);
788 /* set up first page */
789 pb
->pb_pages
[0] = mem_to_page(mem
);
791 ptr
+= PAGE_CACHE_SIZE
;
792 pb
->pb_page_count
= ++i
;
794 pb
->pb_pages
[i
] = mem_to_page((void *)ptr
);
795 pb
->pb_page_count
= ++i
;
796 ptr
+= PAGE_CACHE_SIZE
;
800 pb
->pb_count_desired
= pb
->pb_buffer_length
= len
;
801 pb
->pb_flags
|= PBF_MAPPED
;
807 pagebuf_get_no_daddr(
809 xfs_buftarg_t
*target
)
811 size_t malloc_len
= len
;
816 bp
= pagebuf_allocate(0);
817 if (unlikely(bp
== NULL
))
819 _pagebuf_initialize(bp
, target
, 0, len
, PBF_FORCEIO
);
822 data
= kmem_alloc(malloc_len
, KM_SLEEP
| KM_MAYFAIL
);
823 if (unlikely(data
== NULL
))
826 /* check whether alignment matches.. */
827 if ((__psunsigned_t
)data
!=
828 ((__psunsigned_t
)data
& ~target
->pbr_smask
)) {
829 /* .. else double the size and try again */
830 kmem_free(data
, malloc_len
);
835 error
= pagebuf_associate_memory(bp
, data
, len
);
838 bp
->pb_flags
|= _PBF_KMEM_ALLOC
;
842 PB_TRACE(bp
, "no_daddr", data
);
845 kmem_free(data
, malloc_len
);
855 * Increment reference count on buffer, to hold the buffer concurrently
856 * with another thread which may release (free) the buffer asynchronously.
858 * Must hold the buffer already to call this function.
864 atomic_inc(&pb
->pb_hold
);
865 PB_TRACE(pb
, "hold", 0);
871 * pagebuf_rele releases a hold on the specified buffer. If the
872 * the hold count is 1, pagebuf_rele calls pagebuf_free.
878 pb_hash_t
*hash
= pb_hash(pb
);
880 PB_TRACE(pb
, "rele", pb
->pb_relse
);
882 if (atomic_dec_and_lock(&pb
->pb_hold
, &hash
->pb_hash_lock
)) {
886 atomic_inc(&pb
->pb_hold
);
887 spin_unlock(&hash
->pb_hash_lock
);
888 (*(pb
->pb_relse
)) (pb
);
889 spin_lock(&hash
->pb_hash_lock
);
893 if (pb
->pb_flags
& PBF_DELWRI
) {
894 pb
->pb_flags
|= PBF_ASYNC
;
895 atomic_inc(&pb
->pb_hold
);
896 pagebuf_delwri_queue(pb
, 0);
898 } else if (pb
->pb_flags
& PBF_FS_MANAGED
) {
903 list_del_init(&pb
->pb_hash_list
);
904 spin_unlock(&hash
->pb_hash_lock
);
907 spin_unlock(&hash
->pb_hash_lock
);
914 * Mutual exclusion on buffers. Locking model:
916 * Buffers associated with inodes for which buffer locking
917 * is not enabled are not protected by semaphores, and are
918 * assumed to be exclusively owned by the caller. There is a
919 * spinlock in the buffer, used by the caller when concurrent
920 * access is possible.
926 * pagebuf_cond_lock locks a buffer object, if it is not already locked.
927 * Note that this in no way
928 * locks the underlying pages, so it is only useful for synchronizing
929 * concurrent use of page buffer objects, not for synchronizing independent
930 * access to the underlying pages.
933 pagebuf_cond_lock( /* lock buffer, if not locked */
934 /* returns -EBUSY if locked) */
939 locked
= down_trylock(&pb
->pb_sema
) == 0;
943 PB_TRACE(pb
, "cond_lock", (long)locked
);
944 return(locked
? 0 : -EBUSY
);
950 * Return lock value for a pagebuf
956 return(atomic_read(&pb
->pb_sema
.count
));
962 * pagebuf_lock locks a buffer object. Note that this in no way
963 * locks the underlying pages, so it is only useful for synchronizing
964 * concurrent use of page buffer objects, not for synchronizing independent
965 * access to the underlying pages.
971 PB_TRACE(pb
, "lock", 0);
972 if (atomic_read(&pb
->pb_io_remaining
))
973 blk_run_address_space(pb
->pb_target
->pbr_mapping
);
976 PB_TRACE(pb
, "locked", 0);
983 * pagebuf_unlock releases the lock on the buffer object created by
984 * pagebuf_lock or pagebuf_cond_lock (not any
985 * pinning of underlying pages created by pagebuf_pin).
988 pagebuf_unlock( /* unlock buffer */
989 xfs_buf_t
*pb
) /* buffer to unlock */
993 PB_TRACE(pb
, "unlock", 0);
998 * Pinning Buffer Storage in Memory
1004 * pagebuf_pin locks all of the memory represented by a buffer in
1005 * memory. Multiple calls to pagebuf_pin and pagebuf_unpin, for
1006 * the same or different buffers affecting a given page, will
1007 * properly count the number of outstanding "pin" requests. The
1008 * buffer may be released after the pagebuf_pin and a different
1009 * buffer used when calling pagebuf_unpin, if desired.
1010 * pagebuf_pin should be used by the file system when it wants be
1011 * assured that no attempt will be made to force the affected
1012 * memory to disk. It does not assure that a given logical page
1013 * will not be moved to a different physical page.
1019 atomic_inc(&pb
->pb_pin_count
);
1020 PB_TRACE(pb
, "pin", (long)pb
->pb_pin_count
.counter
);
1026 * pagebuf_unpin reverses the locking of memory performed by
1027 * pagebuf_pin. Note that both functions affected the logical
1028 * pages associated with the buffer, not the buffer itself.
1034 if (atomic_dec_and_test(&pb
->pb_pin_count
)) {
1035 wake_up_all(&pb
->pb_waiters
);
1037 PB_TRACE(pb
, "unpin", (long)pb
->pb_pin_count
.counter
);
1044 return atomic_read(&pb
->pb_pin_count
);
1048 * pagebuf_wait_unpin
1050 * pagebuf_wait_unpin waits until all of the memory associated
1051 * with the buffer is not longer locked in memory. It returns
1052 * immediately if none of the affected pages are locked.
1055 _pagebuf_wait_unpin(
1058 DECLARE_WAITQUEUE (wait
, current
);
1060 if (atomic_read(&pb
->pb_pin_count
) == 0)
1063 add_wait_queue(&pb
->pb_waiters
, &wait
);
1065 set_current_state(TASK_UNINTERRUPTIBLE
);
1066 if (atomic_read(&pb
->pb_pin_count
) == 0)
1068 if (atomic_read(&pb
->pb_io_remaining
))
1069 blk_run_address_space(pb
->pb_target
->pbr_mapping
);
1072 remove_wait_queue(&pb
->pb_waiters
, &wait
);
1073 set_current_state(TASK_RUNNING
);
1077 * Buffer Utility Routines
1083 * pagebuf_iodone marks a buffer for which I/O is in progress
1084 * done with respect to that I/O. The pb_iodone routine, if
1085 * present, will be called as a side-effect.
1088 pagebuf_iodone_work(
1091 xfs_buf_t
*bp
= (xfs_buf_t
*)v
;
1094 (*(bp
->pb_iodone
))(bp
);
1095 else if (bp
->pb_flags
& PBF_ASYNC
)
1105 pb
->pb_flags
&= ~(PBF_READ
| PBF_WRITE
);
1106 if (pb
->pb_error
== 0) {
1107 pb
->pb_flags
&= ~(PBF_PARTIAL
| PBF_NONE
);
1110 PB_TRACE(pb
, "iodone", pb
->pb_iodone
);
1112 if ((pb
->pb_iodone
) || (pb
->pb_flags
& PBF_ASYNC
)) {
1114 INIT_WORK(&pb
->pb_iodone_work
, pagebuf_iodone_work
, pb
);
1115 queue_work(dataio
? pagebuf_dataio_workqueue
:
1116 pagebuf_logio_workqueue
, &pb
->pb_iodone_work
);
1118 pagebuf_iodone_work(pb
);
1121 up(&pb
->pb_iodonesema
);
1128 * pagebuf_ioerror sets the error code for a buffer.
1131 pagebuf_ioerror( /* mark/clear buffer error flag */
1132 xfs_buf_t
*pb
, /* buffer to mark */
1133 int error
) /* error to store (0 if none) */
1135 ASSERT(error
>= 0 && error
<= 0xffff);
1136 pb
->pb_error
= (unsigned short)error
;
1137 PB_TRACE(pb
, "ioerror", (unsigned long)error
);
1143 * pagebuf_iostart initiates I/O on a buffer, based on the flags supplied.
1144 * If necessary, it will arrange for any disk space allocation required,
1145 * and it will break up the request if the block mappings require it.
1146 * The pb_iodone routine in the buffer supplied will only be called
1147 * when all of the subsidiary I/O requests, if any, have been completed.
1148 * pagebuf_iostart calls the pagebuf_ioinitiate routine or
1149 * pagebuf_iorequest, if the former routine is not defined, to start
1150 * the I/O on a given low-level request.
1153 pagebuf_iostart( /* start I/O on a buffer */
1154 xfs_buf_t
*pb
, /* buffer to start */
1155 page_buf_flags_t flags
) /* PBF_LOCK, PBF_ASYNC, PBF_READ, */
1156 /* PBF_WRITE, PBF_DELWRI, */
1157 /* PBF_DONT_BLOCK */
1161 PB_TRACE(pb
, "iostart", (unsigned long)flags
);
1163 if (flags
& PBF_DELWRI
) {
1164 pb
->pb_flags
&= ~(PBF_READ
| PBF_WRITE
| PBF_ASYNC
);
1165 pb
->pb_flags
|= flags
& (PBF_DELWRI
| PBF_ASYNC
);
1166 pagebuf_delwri_queue(pb
, 1);
1170 pb
->pb_flags
&= ~(PBF_READ
| PBF_WRITE
| PBF_ASYNC
| PBF_DELWRI
| \
1171 PBF_READ_AHEAD
| _PBF_RUN_QUEUES
);
1172 pb
->pb_flags
|= flags
& (PBF_READ
| PBF_WRITE
| PBF_ASYNC
| \
1173 PBF_READ_AHEAD
| _PBF_RUN_QUEUES
);
1175 BUG_ON(pb
->pb_bn
== XFS_BUF_DADDR_NULL
);
1177 /* For writes allow an alternate strategy routine to precede
1178 * the actual I/O request (which may not be issued at all in
1179 * a shutdown situation, for example).
1181 status
= (flags
& PBF_WRITE
) ?
1182 pagebuf_iostrategy(pb
) : pagebuf_iorequest(pb
);
1184 /* Wait for I/O if we are not an async request.
1185 * Note: async I/O request completion will release the buffer,
1186 * and that can already be done by this point. So using the
1187 * buffer pointer from here on, after async I/O, is invalid.
1189 if (!status
&& !(flags
& PBF_ASYNC
))
1190 status
= pagebuf_iowait(pb
);
1196 * Helper routine for pagebuf_iorequest
1199 STATIC __inline__
int
1203 ASSERT(pb
->pb_flags
& (PBF_READ
|PBF_WRITE
));
1204 if (pb
->pb_flags
& PBF_READ
)
1205 return pb
->pb_locked
;
1209 STATIC __inline__
void
1214 if (atomic_dec_and_test(&pb
->pb_io_remaining
) == 1) {
1216 pagebuf_iodone(pb
, (pb
->pb_flags
& PBF_FS_DATAIOD
), schedule
);
1223 unsigned int bytes_done
,
1226 xfs_buf_t
*pb
= (xfs_buf_t
*)bio
->bi_private
;
1227 unsigned int i
, blocksize
= pb
->pb_target
->pbr_bsize
;
1228 unsigned int sectorshift
= pb
->pb_target
->pbr_sshift
;
1229 struct bio_vec
*bvec
= bio
->bi_io_vec
;
1234 if (!test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1237 for (i
= 0; i
< bio
->bi_vcnt
; i
++, bvec
++) {
1238 struct page
*page
= bvec
->bv_page
;
1242 } else if (blocksize
== PAGE_CACHE_SIZE
) {
1243 SetPageUptodate(page
);
1244 } else if (!PagePrivate(page
) &&
1245 (pb
->pb_flags
& _PBF_PAGE_CACHE
)) {
1246 unsigned long j
, range
;
1248 ASSERT(blocksize
< PAGE_CACHE_SIZE
);
1249 range
= (bvec
->bv_offset
+ bvec
->bv_len
) >> sectorshift
;
1250 for (j
= bvec
->bv_offset
>> sectorshift
; j
< range
; j
++)
1251 set_bit(j
, &page
->private);
1252 if (page
->private == (unsigned long)(PAGE_CACHE_SIZE
-1))
1253 SetPageUptodate(page
);
1256 if (_pagebuf_iolocked(pb
)) {
1261 _pagebuf_iodone(pb
, 1);
1270 int i
, map_i
, total_nr_pages
, nr_pages
;
1272 int offset
= pb
->pb_offset
;
1273 int size
= pb
->pb_count_desired
;
1274 sector_t sector
= pb
->pb_bn
;
1275 unsigned int blocksize
= pb
->pb_target
->pbr_bsize
;
1276 int locking
= _pagebuf_iolocked(pb
);
1278 total_nr_pages
= pb
->pb_page_count
;
1281 /* Special code path for reading a sub page size pagebuf in --
1282 * we populate up the whole page, and hence the other metadata
1283 * in the same page. This optimization is only valid when the
1284 * filesystem block size and the page size are equal.
1286 if ((pb
->pb_buffer_length
< PAGE_CACHE_SIZE
) &&
1287 (pb
->pb_flags
& PBF_READ
) && locking
&&
1288 (blocksize
== PAGE_CACHE_SIZE
)) {
1289 bio
= bio_alloc(GFP_NOIO
, 1);
1291 bio
->bi_bdev
= pb
->pb_target
->pbr_bdev
;
1292 bio
->bi_sector
= sector
- (offset
>> BBSHIFT
);
1293 bio
->bi_end_io
= bio_end_io_pagebuf
;
1294 bio
->bi_private
= pb
;
1296 bio_add_page(bio
, pb
->pb_pages
[0], PAGE_CACHE_SIZE
, 0);
1299 atomic_inc(&pb
->pb_io_remaining
);
1304 /* Lock down the pages which we need to for the request */
1305 if (locking
&& (pb
->pb_flags
& PBF_WRITE
) && (pb
->pb_locked
== 0)) {
1306 for (i
= 0; size
; i
++) {
1307 int nbytes
= PAGE_CACHE_SIZE
- offset
;
1308 struct page
*page
= pb
->pb_pages
[i
];
1318 offset
= pb
->pb_offset
;
1319 size
= pb
->pb_count_desired
;
1323 atomic_inc(&pb
->pb_io_remaining
);
1324 nr_pages
= BIO_MAX_SECTORS
>> (PAGE_SHIFT
- BBSHIFT
);
1325 if (nr_pages
> total_nr_pages
)
1326 nr_pages
= total_nr_pages
;
1328 bio
= bio_alloc(GFP_NOIO
, nr_pages
);
1329 bio
->bi_bdev
= pb
->pb_target
->pbr_bdev
;
1330 bio
->bi_sector
= sector
;
1331 bio
->bi_end_io
= bio_end_io_pagebuf
;
1332 bio
->bi_private
= pb
;
1334 for (; size
&& nr_pages
; nr_pages
--, map_i
++) {
1335 int nbytes
= PAGE_CACHE_SIZE
- offset
;
1340 if (bio_add_page(bio
, pb
->pb_pages
[map_i
],
1341 nbytes
, offset
) < nbytes
)
1345 sector
+= nbytes
>> BBSHIFT
;
1351 if (likely(bio
->bi_size
)) {
1352 submit_bio((pb
->pb_flags
& PBF_READ
) ? READ
: WRITE
, bio
);
1357 pagebuf_ioerror(pb
, EIO
);
1360 if (pb
->pb_flags
& _PBF_RUN_QUEUES
) {
1361 pb
->pb_flags
&= ~_PBF_RUN_QUEUES
;
1362 if (atomic_read(&pb
->pb_io_remaining
) > 1)
1363 blk_run_address_space(pb
->pb_target
->pbr_mapping
);
1368 * pagebuf_iorequest -- the core I/O request routine.
1371 pagebuf_iorequest( /* start real I/O */
1372 xfs_buf_t
*pb
) /* buffer to convey to device */
1374 PB_TRACE(pb
, "iorequest", 0);
1376 if (pb
->pb_flags
& PBF_DELWRI
) {
1377 pagebuf_delwri_queue(pb
, 1);
1381 if (pb
->pb_flags
& PBF_WRITE
) {
1382 _pagebuf_wait_unpin(pb
);
1387 /* Set the count to 1 initially, this will stop an I/O
1388 * completion callout which happens before we have started
1389 * all the I/O from calling pagebuf_iodone too early.
1391 atomic_set(&pb
->pb_io_remaining
, 1);
1392 _pagebuf_ioapply(pb
);
1393 _pagebuf_iodone(pb
, 0);
1402 * pagebuf_iowait waits for I/O to complete on the buffer supplied.
1403 * It returns immediately if no I/O is pending. In any case, it returns
1404 * the error code, if any, or 0 if there is no error.
1410 PB_TRACE(pb
, "iowait", 0);
1411 if (atomic_read(&pb
->pb_io_remaining
))
1412 blk_run_address_space(pb
->pb_target
->pbr_mapping
);
1413 down(&pb
->pb_iodonesema
);
1414 PB_TRACE(pb
, "iowaited", (long)pb
->pb_error
);
1415 return pb
->pb_error
;
1425 offset
+= pb
->pb_offset
;
1427 page
= pb
->pb_pages
[offset
>> PAGE_CACHE_SHIFT
];
1428 return (caddr_t
) page_address(page
) + (offset
& (PAGE_CACHE_SIZE
- 1));
1434 * Move data into or out of a buffer.
1438 xfs_buf_t
*pb
, /* buffer to process */
1439 size_t boff
, /* starting buffer offset */
1440 size_t bsize
, /* length to copy */
1441 caddr_t data
, /* data address */
1442 page_buf_rw_t mode
) /* read/write flag */
1444 size_t bend
, cpoff
, csize
;
1447 bend
= boff
+ bsize
;
1448 while (boff
< bend
) {
1449 page
= pb
->pb_pages
[page_buf_btoct(boff
+ pb
->pb_offset
)];
1450 cpoff
= page_buf_poff(boff
+ pb
->pb_offset
);
1451 csize
= min_t(size_t,
1452 PAGE_CACHE_SIZE
-cpoff
, pb
->pb_count_desired
-boff
);
1454 ASSERT(((csize
+ cpoff
) <= PAGE_CACHE_SIZE
));
1458 memset(page_address(page
) + cpoff
, 0, csize
);
1461 memcpy(data
, page_address(page
) + cpoff
, csize
);
1464 memcpy(page_address(page
) + cpoff
, data
, csize
);
1473 * Handling of buftargs.
1481 xfs_flush_buftarg(btp
, 1);
1483 xfs_blkdev_put(btp
->pbr_bdev
);
1484 iput(btp
->pbr_mapping
->host
);
1485 kmem_free(btp
, sizeof(*btp
));
1494 invalidate_bdev(btp
->pbr_bdev
, 1);
1495 truncate_inode_pages(btp
->pbr_mapping
, 0LL);
1499 xfs_setsize_buftarg(
1501 unsigned int blocksize
,
1502 unsigned int sectorsize
)
1504 btp
->pbr_bsize
= blocksize
;
1505 btp
->pbr_sshift
= ffs(sectorsize
) - 1;
1506 btp
->pbr_smask
= sectorsize
- 1;
1508 if (set_blocksize(btp
->pbr_bdev
, sectorsize
)) {
1510 "XFS: Cannot set_blocksize to %u on device %s\n",
1511 sectorsize
, XFS_BUFTARG_NAME(btp
));
1518 xfs_mapping_buftarg(
1520 struct block_device
*bdev
)
1522 struct backing_dev_info
*bdi
;
1523 struct inode
*inode
;
1524 struct address_space
*mapping
;
1525 static struct address_space_operations mapping_aops
= {
1526 .sync_page
= block_sync_page
,
1529 inode
= new_inode(bdev
->bd_inode
->i_sb
);
1532 "XFS: Cannot allocate mapping inode for device %s\n",
1533 XFS_BUFTARG_NAME(btp
));
1536 inode
->i_mode
= S_IFBLK
;
1537 inode
->i_bdev
= bdev
;
1538 inode
->i_rdev
= bdev
->bd_dev
;
1539 bdi
= blk_get_backing_dev_info(bdev
);
1541 bdi
= &default_backing_dev_info
;
1542 mapping
= &inode
->i_data
;
1543 mapping
->a_ops
= &mapping_aops
;
1544 mapping
->backing_dev_info
= bdi
;
1545 mapping_set_gfp_mask(mapping
, GFP_KERNEL
);
1546 btp
->pbr_mapping
= mapping
;
1552 struct block_device
*bdev
)
1556 btp
= kmem_zalloc(sizeof(*btp
), KM_SLEEP
);
1558 btp
->pbr_dev
= bdev
->bd_dev
;
1559 btp
->pbr_bdev
= bdev
;
1560 if (xfs_setsize_buftarg(btp
, PAGE_CACHE_SIZE
, bdev_hardsect_size(bdev
)))
1562 if (xfs_mapping_buftarg(btp
, bdev
))
1567 kmem_free(btp
, sizeof(*btp
));
1573 * Pagebuf delayed write buffer handling
1576 STATIC
LIST_HEAD(pbd_delwrite_queue
);
1577 STATIC spinlock_t pbd_delwrite_lock
= SPIN_LOCK_UNLOCKED
;
1580 pagebuf_delwri_queue(
1584 PB_TRACE(pb
, "delwri_q", (long)unlock
);
1585 ASSERT(pb
->pb_flags
& PBF_DELWRI
);
1587 spin_lock(&pbd_delwrite_lock
);
1588 /* If already in the queue, dequeue and place at tail */
1589 if (!list_empty(&pb
->pb_list
)) {
1591 atomic_dec(&pb
->pb_hold
);
1593 list_del(&pb
->pb_list
);
1596 list_add_tail(&pb
->pb_list
, &pbd_delwrite_queue
);
1597 pb
->pb_queuetime
= jiffies
;
1598 spin_unlock(&pbd_delwrite_lock
);
1605 pagebuf_delwri_dequeue(
1610 spin_lock(&pbd_delwrite_lock
);
1611 if ((pb
->pb_flags
& PBF_DELWRI
) && !list_empty(&pb
->pb_list
)) {
1612 list_del_init(&pb
->pb_list
);
1615 pb
->pb_flags
&= ~PBF_DELWRI
;
1616 spin_unlock(&pbd_delwrite_lock
);
1621 PB_TRACE(pb
, "delwri_dq", (long)dequeued
);
1625 pagebuf_runall_queues(
1626 struct workqueue_struct
*queue
)
1628 flush_workqueue(queue
);
1631 /* Defines for pagebuf daemon */
1632 STATIC
DECLARE_COMPLETION(pagebuf_daemon_done
);
1633 STATIC
struct task_struct
*pagebuf_daemon_task
;
1634 STATIC
int pagebuf_daemon_active
;
1635 STATIC
int force_flush
;
1639 pagebuf_daemon_wakeup(
1645 wake_up_process(pagebuf_daemon_task
);
1653 struct list_head tmp
;
1655 xfs_buftarg_t
*target
;
1658 /* Set up the thread */
1659 daemonize("xfsbufd");
1660 current
->flags
|= PF_MEMALLOC
;
1662 pagebuf_daemon_task
= current
;
1663 pagebuf_daemon_active
= 1;
1666 INIT_LIST_HEAD(&tmp
);
1669 if (current
->flags
& PF_FREEZE
)
1670 refrigerator(PF_FREEZE
);
1672 set_current_state(TASK_INTERRUPTIBLE
);
1673 schedule_timeout((xfs_buf_timer_centisecs
* HZ
) / 100);
1675 age
= (xfs_buf_age_centisecs
* HZ
) / 100;
1676 spin_lock(&pbd_delwrite_lock
);
1677 list_for_each_entry_safe(pb
, n
, &pbd_delwrite_queue
, pb_list
) {
1678 PB_TRACE(pb
, "walkq1", (long)pagebuf_ispin(pb
));
1679 ASSERT(pb
->pb_flags
& PBF_DELWRI
);
1681 if (!pagebuf_ispin(pb
) && !pagebuf_cond_lock(pb
)) {
1683 time_before(jiffies
,
1684 pb
->pb_queuetime
+ age
)) {
1689 pb
->pb_flags
&= ~PBF_DELWRI
;
1690 pb
->pb_flags
|= PBF_WRITE
;
1691 list_move(&pb
->pb_list
, &tmp
);
1694 spin_unlock(&pbd_delwrite_lock
);
1696 while (!list_empty(&tmp
)) {
1697 pb
= list_entry(tmp
.next
, xfs_buf_t
, pb_list
);
1698 target
= pb
->pb_target
;
1700 list_del_init(&pb
->pb_list
);
1701 pagebuf_iostrategy(pb
);
1703 blk_run_address_space(target
->pbr_mapping
);
1706 if (as_list_len
> 0)
1710 } while (pagebuf_daemon_active
);
1712 complete_and_exit(&pagebuf_daemon_done
, 0);
1716 * Go through all incore buffers, and release buffers if they belong to
1717 * the given device. This is used in filesystem error handling to
1718 * preserve the consistency of its metadata.
1722 xfs_buftarg_t
*target
,
1725 struct list_head tmp
;
1729 pagebuf_runall_queues(pagebuf_dataio_workqueue
);
1730 pagebuf_runall_queues(pagebuf_logio_workqueue
);
1732 INIT_LIST_HEAD(&tmp
);
1733 spin_lock(&pbd_delwrite_lock
);
1734 list_for_each_entry_safe(pb
, n
, &pbd_delwrite_queue
, pb_list
) {
1736 if (pb
->pb_target
!= target
)
1739 ASSERT(pb
->pb_flags
& PBF_DELWRI
);
1740 PB_TRACE(pb
, "walkq2", (long)pagebuf_ispin(pb
));
1741 if (pagebuf_ispin(pb
)) {
1746 pb
->pb_flags
&= ~PBF_DELWRI
;
1747 pb
->pb_flags
|= PBF_WRITE
;
1748 list_move(&pb
->pb_list
, &tmp
);
1750 spin_unlock(&pbd_delwrite_lock
);
1753 * Dropped the delayed write list lock, now walk the temporary list
1755 list_for_each_entry_safe(pb
, n
, &tmp
, pb_list
) {
1757 pb
->pb_flags
&= ~PBF_ASYNC
;
1759 list_del_init(&pb
->pb_list
);
1762 pagebuf_iostrategy(pb
);
1766 * Remaining list items must be flushed before returning
1768 while (!list_empty(&tmp
)) {
1769 pb
= list_entry(tmp
.next
, xfs_buf_t
, pb_list
);
1771 list_del_init(&pb
->pb_list
);
1777 blk_run_address_space(target
->pbr_mapping
);
1783 pagebuf_daemon_start(void)
1787 pagebuf_logio_workqueue
= create_workqueue("xfslogd");
1788 if (!pagebuf_logio_workqueue
)
1791 pagebuf_dataio_workqueue
= create_workqueue("xfsdatad");
1792 if (!pagebuf_dataio_workqueue
) {
1793 destroy_workqueue(pagebuf_logio_workqueue
);
1797 rval
= kernel_thread(pagebuf_daemon
, NULL
, CLONE_FS
|CLONE_FILES
);
1799 destroy_workqueue(pagebuf_logio_workqueue
);
1800 destroy_workqueue(pagebuf_dataio_workqueue
);
1807 * pagebuf_daemon_stop
1809 * Note: do not mark as __exit, it is called from pagebuf_terminate.
1812 pagebuf_daemon_stop(void)
1814 pagebuf_daemon_active
= 0;
1816 wait_for_completion(&pagebuf_daemon_done
);
1818 destroy_workqueue(pagebuf_logio_workqueue
);
1819 destroy_workqueue(pagebuf_dataio_workqueue
);
1823 * Initialization and Termination
1831 pagebuf_cache
= kmem_cache_create("xfs_buf_t", sizeof(xfs_buf_t
), 0,
1832 SLAB_HWCACHE_ALIGN
, NULL
, NULL
);
1833 if (pagebuf_cache
== NULL
) {
1834 printk("XFS: couldn't init xfs_buf_t cache\n");
1835 pagebuf_terminate();
1839 #ifdef PAGEBUF_TRACE
1840 pagebuf_trace_buf
= ktrace_alloc(PAGEBUF_TRACE_SIZE
, KM_SLEEP
);
1843 pagebuf_daemon_start();
1845 pagebuf_shake
= kmem_shake_register(pagebuf_daemon_wakeup
);
1846 if (pagebuf_shake
== NULL
) {
1847 pagebuf_terminate();
1851 for (i
= 0; i
< NHASH
; i
++) {
1852 spin_lock_init(&pbhash
[i
].pb_hash_lock
);
1853 INIT_LIST_HEAD(&pbhash
[i
].pb_hash
);
1861 * pagebuf_terminate.
1863 * Note: do not mark as __exit, this is also called from the __init code.
1866 pagebuf_terminate(void)
1868 pagebuf_daemon_stop();
1870 #ifdef PAGEBUF_TRACE
1871 ktrace_free(pagebuf_trace_buf
);
1874 kmem_zone_destroy(pagebuf_cache
);
1875 kmem_shake_deregister(pagebuf_shake
);