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/percpu.h>
55 #include <linux/blkdev.h>
56 #include <linux/hash.h>
58 #include "xfs_linux.h"
64 STATIC kmem_cache_t
*pagebuf_cache
;
65 STATIC kmem_shaker_t pagebuf_shake
;
66 STATIC
int pagebuf_daemon_wakeup(int, unsigned int);
67 STATIC
void pagebuf_delwri_queue(xfs_buf_t
*, int);
68 STATIC
struct workqueue_struct
*pagebuf_logio_workqueue
;
69 STATIC
struct workqueue_struct
*pagebuf_dataio_workqueue
;
83 ktrace_enter(pagebuf_trace_buf
,
85 (void *)(unsigned long)pb
->pb_flags
,
86 (void *)(unsigned long)pb
->pb_hold
.counter
,
87 (void *)(unsigned long)pb
->pb_sema
.count
.counter
,
90 (void *)(unsigned long)((pb
->pb_file_offset
>>32) & 0xffffffff),
91 (void *)(unsigned long)(pb
->pb_file_offset
& 0xffffffff),
92 (void *)(unsigned long)pb
->pb_buffer_length
,
93 NULL
, NULL
, NULL
, NULL
, NULL
);
95 ktrace_t
*pagebuf_trace_buf
;
96 #define PAGEBUF_TRACE_SIZE 4096
97 #define PB_TRACE(pb, id, data) \
98 pagebuf_trace(pb, id, (void *)data, (void *)__builtin_return_address(0))
100 #define PB_TRACE(pb, id, data) do { } while (0)
103 #ifdef PAGEBUF_LOCK_TRACKING
104 # define PB_SET_OWNER(pb) ((pb)->pb_last_holder = current->pid)
105 # define PB_CLEAR_OWNER(pb) ((pb)->pb_last_holder = -1)
106 # define PB_GET_OWNER(pb) ((pb)->pb_last_holder)
108 # define PB_SET_OWNER(pb) do { } while (0)
109 # define PB_CLEAR_OWNER(pb) do { } while (0)
110 # define PB_GET_OWNER(pb) do { } while (0)
114 * Pagebuf allocation / freeing.
117 #define pb_to_gfp(flags) \
118 ((((flags) & PBF_READ_AHEAD) ? __GFP_NORETRY : \
119 ((flags) & PBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN)
121 #define pb_to_km(flags) \
122 (((flags) & PBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP)
125 #define pagebuf_allocate(flags) \
126 kmem_zone_alloc(pagebuf_cache, pb_to_km(flags))
127 #define pagebuf_deallocate(pb) \
128 kmem_zone_free(pagebuf_cache, (pb));
131 * Page Region interfaces.
133 * For pages in filesystems where the blocksize is smaller than the
134 * pagesize, we use the page->private field (long) to hold a bitmap
135 * of uptodate regions within the page.
137 * Each such region is "bytes per page / bits per long" bytes long.
139 * NBPPR == number-of-bytes-per-page-region
140 * BTOPR == bytes-to-page-region (rounded up)
141 * BTOPRT == bytes-to-page-region-truncated (rounded down)
143 #if (BITS_PER_LONG == 32)
144 #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */
145 #elif (BITS_PER_LONG == 64)
146 #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */
148 #error BITS_PER_LONG must be 32 or 64
150 #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG)
151 #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT)
152 #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT))
162 first
= BTOPR(offset
);
163 final
= BTOPRT(offset
+ length
- 1);
164 first
= min(first
, final
);
167 mask
<<= BITS_PER_LONG
- (final
- first
);
168 mask
>>= BITS_PER_LONG
- (final
);
170 ASSERT(offset
+ length
<= PAGE_CACHE_SIZE
);
171 ASSERT((final
- first
) < BITS_PER_LONG
&& (final
- first
) >= 0);
182 page
->private |= page_region_mask(offset
, length
);
183 if (page
->private == ~0UL)
184 SetPageUptodate(page
);
193 unsigned long mask
= page_region_mask(offset
, length
);
195 return (mask
&& (page
->private & mask
) == mask
);
199 * Mapping of multi-page buffers into contiguous virtual space
202 typedef struct a_list
{
207 STATIC a_list_t
*as_free_head
;
208 STATIC
int as_list_len
;
209 STATIC
DEFINE_SPINLOCK(as_lock
);
212 * Try to batch vunmaps because they are costly.
220 aentry
= kmalloc(sizeof(a_list_t
), GFP_ATOMIC
& ~__GFP_HIGH
);
221 if (likely(aentry
)) {
223 aentry
->next
= as_free_head
;
224 aentry
->vm_addr
= addr
;
225 as_free_head
= aentry
;
227 spin_unlock(&as_lock
);
234 purge_addresses(void)
236 a_list_t
*aentry
, *old
;
238 if (as_free_head
== NULL
)
242 aentry
= as_free_head
;
245 spin_unlock(&as_lock
);
247 while ((old
= aentry
) != NULL
) {
248 vunmap(aentry
->vm_addr
);
249 aentry
= aentry
->next
;
255 * Internal pagebuf object manipulation
261 xfs_buftarg_t
*target
,
264 page_buf_flags_t flags
)
267 * We don't want certain flags to appear in pb->pb_flags.
269 flags
&= ~(PBF_LOCK
|PBF_MAPPED
|PBF_DONT_BLOCK
|PBF_READ_AHEAD
);
271 memset(pb
, 0, sizeof(xfs_buf_t
));
272 atomic_set(&pb
->pb_hold
, 1);
273 init_MUTEX_LOCKED(&pb
->pb_iodonesema
);
274 INIT_LIST_HEAD(&pb
->pb_list
);
275 INIT_LIST_HEAD(&pb
->pb_hash_list
);
276 init_MUTEX_LOCKED(&pb
->pb_sema
); /* held, no waiters */
278 pb
->pb_target
= target
;
279 pb
->pb_file_offset
= range_base
;
281 * Set buffer_length and count_desired to the same value initially.
282 * I/O routines should use count_desired, which will be the same in
283 * most cases but may be reset (e.g. XFS recovery).
285 pb
->pb_buffer_length
= pb
->pb_count_desired
= range_length
;
286 pb
->pb_flags
= flags
| PBF_NONE
;
287 pb
->pb_bn
= XFS_BUF_DADDR_NULL
;
288 atomic_set(&pb
->pb_pin_count
, 0);
289 init_waitqueue_head(&pb
->pb_waiters
);
291 XFS_STATS_INC(pb_create
);
292 PB_TRACE(pb
, "initialize", target
);
296 * Allocate a page array capable of holding a specified number
297 * of pages, and point the page buf at it.
303 page_buf_flags_t flags
)
305 /* Make sure that we have a page list */
306 if (pb
->pb_pages
== NULL
) {
307 pb
->pb_offset
= page_buf_poff(pb
->pb_file_offset
);
308 pb
->pb_page_count
= page_count
;
309 if (page_count
<= PB_PAGES
) {
310 pb
->pb_pages
= pb
->pb_page_array
;
312 pb
->pb_pages
= kmem_alloc(sizeof(struct page
*) *
313 page_count
, pb_to_km(flags
));
314 if (pb
->pb_pages
== NULL
)
317 memset(pb
->pb_pages
, 0, sizeof(struct page
*) * page_count
);
323 * Frees pb_pages if it was malloced.
329 if (bp
->pb_pages
!= bp
->pb_page_array
) {
330 kmem_free(bp
->pb_pages
,
331 bp
->pb_page_count
* sizeof(struct page
*));
336 * Releases the specified buffer.
338 * The modification state of any associated pages is left unchanged.
339 * The buffer most not be on any hash - use pagebuf_rele instead for
340 * hashed and refcounted buffers
346 PB_TRACE(bp
, "free", 0);
348 ASSERT(list_empty(&bp
->pb_hash_list
));
350 if (bp
->pb_flags
& _PBF_PAGE_CACHE
) {
353 if ((bp
->pb_flags
& PBF_MAPPED
) && (bp
->pb_page_count
> 1))
354 free_address(bp
->pb_addr
- bp
->pb_offset
);
356 for (i
= 0; i
< bp
->pb_page_count
; i
++)
357 page_cache_release(bp
->pb_pages
[i
]);
358 _pagebuf_free_pages(bp
);
359 } else if (bp
->pb_flags
& _PBF_KMEM_ALLOC
) {
361 * XXX(hch): bp->pb_count_desired might be incorrect (see
362 * pagebuf_associate_memory for details), but fortunately
363 * the Linux version of kmem_free ignores the len argument..
365 kmem_free(bp
->pb_addr
, bp
->pb_count_desired
);
366 _pagebuf_free_pages(bp
);
369 pagebuf_deallocate(bp
);
373 * Finds all pages for buffer in question and builds it's page list.
376 _pagebuf_lookup_pages(
380 struct address_space
*mapping
= bp
->pb_target
->pbr_mapping
;
381 size_t blocksize
= bp
->pb_target
->pbr_bsize
;
382 size_t size
= bp
->pb_count_desired
;
383 size_t nbytes
, offset
;
384 int gfp_mask
= pb_to_gfp(flags
);
385 unsigned short page_count
, i
;
390 end
= bp
->pb_file_offset
+ bp
->pb_buffer_length
;
391 page_count
= page_buf_btoc(end
) - page_buf_btoct(bp
->pb_file_offset
);
393 error
= _pagebuf_get_pages(bp
, page_count
, flags
);
396 bp
->pb_flags
|= _PBF_PAGE_CACHE
;
398 offset
= bp
->pb_offset
;
399 first
= bp
->pb_file_offset
>> PAGE_CACHE_SHIFT
;
401 for (i
= 0; i
< bp
->pb_page_count
; i
++) {
406 page
= find_or_create_page(mapping
, first
+ i
, gfp_mask
);
407 if (unlikely(page
== NULL
)) {
408 if (flags
& PBF_READ_AHEAD
) {
409 bp
->pb_page_count
= i
;
410 for (i
= 0; i
< bp
->pb_page_count
; i
++)
411 unlock_page(bp
->pb_pages
[i
]);
416 * This could deadlock.
418 * But until all the XFS lowlevel code is revamped to
419 * handle buffer allocation failures we can't do much.
421 if (!(++retries
% 100))
423 "XFS: possible memory allocation "
424 "deadlock in %s (mode:0x%x)\n",
425 __FUNCTION__
, gfp_mask
);
427 XFS_STATS_INC(pb_page_retries
);
428 pagebuf_daemon_wakeup(0, gfp_mask
);
429 blk_congestion_wait(WRITE
, HZ
/50);
433 XFS_STATS_INC(pb_page_found
);
435 nbytes
= min_t(size_t, size
, PAGE_CACHE_SIZE
- offset
);
438 if (!PageUptodate(page
)) {
440 if (blocksize
>= PAGE_CACHE_SIZE
) {
441 if (flags
& PBF_READ
)
443 } else if (!PagePrivate(page
)) {
444 if (test_page_region(page
, offset
, nbytes
))
449 bp
->pb_pages
[i
] = page
;
453 if (!bp
->pb_locked
) {
454 for (i
= 0; i
< bp
->pb_page_count
; i
++)
455 unlock_page(bp
->pb_pages
[i
]);
459 /* if we have any uptodate pages, mark that in the buffer */
460 bp
->pb_flags
&= ~PBF_NONE
;
462 /* if some pages aren't uptodate, mark that in the buffer */
463 if (page_count
!= bp
->pb_page_count
)
464 bp
->pb_flags
|= PBF_PARTIAL
;
467 PB_TRACE(bp
, "lookup_pages", (long)page_count
);
472 * Map buffer into kernel address-space if nessecary.
479 /* A single page buffer is always mappable */
480 if (bp
->pb_page_count
== 1) {
481 bp
->pb_addr
= page_address(bp
->pb_pages
[0]) + bp
->pb_offset
;
482 bp
->pb_flags
|= PBF_MAPPED
;
483 } else if (flags
& PBF_MAPPED
) {
484 if (as_list_len
> 64)
486 bp
->pb_addr
= vmap(bp
->pb_pages
, bp
->pb_page_count
,
487 VM_MAP
, PAGE_KERNEL
);
488 if (unlikely(bp
->pb_addr
== NULL
))
490 bp
->pb_addr
+= bp
->pb_offset
;
491 bp
->pb_flags
|= PBF_MAPPED
;
498 * Finding and Reading Buffers
504 * Looks up, and creates if absent, a lockable buffer for
505 * a given range of an inode. The buffer is returned
506 * locked. If other overlapping buffers exist, they are
507 * released before the new buffer is created and locked,
508 * which may imply that this call will block until those buffers
509 * are unlocked. No I/O is implied by this call.
513 xfs_buftarg_t
*btp
, /* block device target */
514 loff_t ioff
, /* starting offset of range */
515 size_t isize
, /* length of range */
516 page_buf_flags_t flags
, /* PBF_TRYLOCK */
517 xfs_buf_t
*new_pb
)/* newly allocated buffer */
524 range_base
= (ioff
<< BBSHIFT
);
525 range_length
= (isize
<< BBSHIFT
);
527 /* Check for IOs smaller than the sector size / not sector aligned */
528 ASSERT(!(range_length
< (1 << btp
->pbr_sshift
)));
529 ASSERT(!(range_base
& (loff_t
)btp
->pbr_smask
));
531 hash
= &btp
->bt_hash
[hash_long((unsigned long)ioff
, btp
->bt_hashshift
)];
533 spin_lock(&hash
->bh_lock
);
535 list_for_each_entry_safe(pb
, n
, &hash
->bh_list
, pb_hash_list
) {
536 ASSERT(btp
== pb
->pb_target
);
537 if (pb
->pb_file_offset
== range_base
&&
538 pb
->pb_buffer_length
== range_length
) {
540 * If we look at something bring it to the
541 * front of the list for next time.
543 atomic_inc(&pb
->pb_hold
);
544 list_move(&pb
->pb_hash_list
, &hash
->bh_list
);
551 _pagebuf_initialize(new_pb
, btp
, range_base
,
552 range_length
, flags
);
553 new_pb
->pb_hash
= hash
;
554 list_add(&new_pb
->pb_hash_list
, &hash
->bh_list
);
556 XFS_STATS_INC(pb_miss_locked
);
559 spin_unlock(&hash
->bh_lock
);
563 spin_unlock(&hash
->bh_lock
);
565 /* Attempt to get the semaphore without sleeping,
566 * if this does not work then we need to drop the
567 * spinlock and do a hard attempt on the semaphore.
569 if (down_trylock(&pb
->pb_sema
)) {
570 if (!(flags
& PBF_TRYLOCK
)) {
571 /* wait for buffer ownership */
572 PB_TRACE(pb
, "get_lock", 0);
574 XFS_STATS_INC(pb_get_locked_waited
);
576 /* We asked for a trylock and failed, no need
577 * to look at file offset and length here, we
578 * know that this pagebuf at least overlaps our
579 * pagebuf and is locked, therefore our buffer
580 * either does not exist, or is this buffer
584 XFS_STATS_INC(pb_busy_locked
);
592 if (pb
->pb_flags
& PBF_STALE
)
593 pb
->pb_flags
&= PBF_MAPPED
;
594 PB_TRACE(pb
, "got_lock", 0);
595 XFS_STATS_INC(pb_get_locked
);
600 * xfs_buf_get_flags assembles a buffer covering the specified range.
602 * Storage in memory for all portions of the buffer will be allocated,
603 * although backing storage may not be.
606 xfs_buf_get_flags( /* allocate a buffer */
607 xfs_buftarg_t
*target
,/* target for buffer */
608 loff_t ioff
, /* starting offset of range */
609 size_t isize
, /* length of range */
610 page_buf_flags_t flags
) /* PBF_TRYLOCK */
612 xfs_buf_t
*pb
, *new_pb
;
615 new_pb
= pagebuf_allocate(flags
);
616 if (unlikely(!new_pb
))
619 pb
= _pagebuf_find(target
, ioff
, isize
, flags
, new_pb
);
621 error
= _pagebuf_lookup_pages(pb
, flags
);
625 pagebuf_deallocate(new_pb
);
626 if (unlikely(pb
== NULL
))
630 for (i
= 0; i
< pb
->pb_page_count
; i
++)
631 mark_page_accessed(pb
->pb_pages
[i
]);
633 if (!(pb
->pb_flags
& PBF_MAPPED
)) {
634 error
= _pagebuf_map_pages(pb
, flags
);
635 if (unlikely(error
)) {
636 printk(KERN_WARNING
"%s: failed to map pages\n",
642 XFS_STATS_INC(pb_get
);
645 * Always fill in the block number now, the mapped cases can do
646 * their own overlay of this later.
649 pb
->pb_count_desired
= pb
->pb_buffer_length
;
651 PB_TRACE(pb
, "get", (unsigned long)flags
);
655 if (flags
& (PBF_LOCK
| PBF_TRYLOCK
))
663 xfs_buftarg_t
*target
,
666 page_buf_flags_t flags
)
672 pb
= xfs_buf_get_flags(target
, ioff
, isize
, flags
);
674 if (PBF_NOT_DONE(pb
)) {
675 PB_TRACE(pb
, "read", (unsigned long)flags
);
676 XFS_STATS_INC(pb_get_read
);
677 pagebuf_iostart(pb
, flags
);
678 } else if (flags
& PBF_ASYNC
) {
679 PB_TRACE(pb
, "read_async", (unsigned long)flags
);
681 * Read ahead call which is already satisfied,
686 PB_TRACE(pb
, "read_done", (unsigned long)flags
);
687 /* We do not want read in the flags */
688 pb
->pb_flags
&= ~PBF_READ
;
695 if (flags
& (PBF_LOCK
| PBF_TRYLOCK
))
702 * Create a skeletal pagebuf (no pages associated with it).
706 xfs_buftarg_t
*target
,
709 page_buf_flags_t flags
)
713 pb
= pagebuf_allocate(flags
);
715 _pagebuf_initialize(pb
, target
, ioff
, isize
, flags
);
721 * If we are not low on memory then do the readahead in a deadlock
726 xfs_buftarg_t
*target
,
729 page_buf_flags_t flags
)
731 struct backing_dev_info
*bdi
;
733 bdi
= target
->pbr_mapping
->backing_dev_info
;
734 if (bdi_read_congested(bdi
))
737 flags
|= (PBF_TRYLOCK
|PBF_ASYNC
|PBF_READ_AHEAD
);
738 xfs_buf_read_flags(target
, ioff
, isize
, flags
);
744 xfs_buftarg_t
*target
)
748 pb
= pagebuf_allocate(0);
750 _pagebuf_initialize(pb
, target
, 0, len
, 0);
754 static inline struct page
*
758 if (((unsigned long)addr
< VMALLOC_START
) ||
759 ((unsigned long)addr
>= VMALLOC_END
)) {
760 return virt_to_page(addr
);
762 return vmalloc_to_page(addr
);
767 pagebuf_associate_memory(
779 page_count
= PAGE_CACHE_ALIGN(len
) >> PAGE_CACHE_SHIFT
;
780 offset
= (off_t
) mem
- ((off_t
)mem
& PAGE_CACHE_MASK
);
781 if (offset
&& (len
> PAGE_CACHE_SIZE
))
784 /* Free any previous set of page pointers */
786 _pagebuf_free_pages(pb
);
791 rval
= _pagebuf_get_pages(pb
, page_count
, 0);
795 pb
->pb_offset
= offset
;
796 ptr
= (size_t) mem
& PAGE_CACHE_MASK
;
797 end
= PAGE_CACHE_ALIGN((size_t) mem
+ len
);
799 /* set up first page */
800 pb
->pb_pages
[0] = mem_to_page(mem
);
802 ptr
+= PAGE_CACHE_SIZE
;
803 pb
->pb_page_count
= ++i
;
805 pb
->pb_pages
[i
] = mem_to_page((void *)ptr
);
806 pb
->pb_page_count
= ++i
;
807 ptr
+= PAGE_CACHE_SIZE
;
811 pb
->pb_count_desired
= pb
->pb_buffer_length
= len
;
812 pb
->pb_flags
|= PBF_MAPPED
;
818 pagebuf_get_no_daddr(
820 xfs_buftarg_t
*target
)
822 size_t malloc_len
= len
;
827 bp
= pagebuf_allocate(0);
828 if (unlikely(bp
== NULL
))
830 _pagebuf_initialize(bp
, target
, 0, len
, PBF_FORCEIO
);
833 data
= kmem_alloc(malloc_len
, KM_SLEEP
| KM_MAYFAIL
);
834 if (unlikely(data
== NULL
))
837 /* check whether alignment matches.. */
838 if ((__psunsigned_t
)data
!=
839 ((__psunsigned_t
)data
& ~target
->pbr_smask
)) {
840 /* .. else double the size and try again */
841 kmem_free(data
, malloc_len
);
846 error
= pagebuf_associate_memory(bp
, data
, len
);
849 bp
->pb_flags
|= _PBF_KMEM_ALLOC
;
853 PB_TRACE(bp
, "no_daddr", data
);
856 kmem_free(data
, malloc_len
);
866 * Increment reference count on buffer, to hold the buffer concurrently
867 * with another thread which may release (free) the buffer asynchronously.
869 * Must hold the buffer already to call this function.
875 atomic_inc(&pb
->pb_hold
);
876 PB_TRACE(pb
, "hold", 0);
882 * pagebuf_rele releases a hold on the specified buffer. If the
883 * the hold count is 1, pagebuf_rele calls pagebuf_free.
889 xfs_bufhash_t
*hash
= pb
->pb_hash
;
891 PB_TRACE(pb
, "rele", pb
->pb_relse
);
894 * pagebuf_lookup buffers are not hashed, not delayed write,
895 * and don't have their own release routines. Special case.
897 if (unlikely(!hash
)) {
898 ASSERT(!pb
->pb_relse
);
899 if (atomic_dec_and_test(&pb
->pb_hold
))
904 if (atomic_dec_and_lock(&pb
->pb_hold
, &hash
->bh_lock
)) {
908 atomic_inc(&pb
->pb_hold
);
909 spin_unlock(&hash
->bh_lock
);
910 (*(pb
->pb_relse
)) (pb
);
911 spin_lock(&hash
->bh_lock
);
915 if (pb
->pb_flags
& PBF_DELWRI
) {
916 pb
->pb_flags
|= PBF_ASYNC
;
917 atomic_inc(&pb
->pb_hold
);
918 pagebuf_delwri_queue(pb
, 0);
920 } else if (pb
->pb_flags
& PBF_FS_MANAGED
) {
925 list_del_init(&pb
->pb_hash_list
);
926 spin_unlock(&hash
->bh_lock
);
929 spin_unlock(&hash
->bh_lock
);
936 * Mutual exclusion on buffers. Locking model:
938 * Buffers associated with inodes for which buffer locking
939 * is not enabled are not protected by semaphores, and are
940 * assumed to be exclusively owned by the caller. There is a
941 * spinlock in the buffer, used by the caller when concurrent
942 * access is possible.
948 * pagebuf_cond_lock locks a buffer object, if it is not already locked.
949 * Note that this in no way
950 * locks the underlying pages, so it is only useful for synchronizing
951 * concurrent use of page buffer objects, not for synchronizing independent
952 * access to the underlying pages.
955 pagebuf_cond_lock( /* lock buffer, if not locked */
956 /* returns -EBUSY if locked) */
961 locked
= down_trylock(&pb
->pb_sema
) == 0;
965 PB_TRACE(pb
, "cond_lock", (long)locked
);
966 return(locked
? 0 : -EBUSY
);
969 #if defined(DEBUG) || defined(XFS_BLI_TRACE)
973 * Return lock value for a pagebuf
979 return(atomic_read(&pb
->pb_sema
.count
));
986 * pagebuf_lock locks a buffer object. Note that this in no way
987 * locks the underlying pages, so it is only useful for synchronizing
988 * concurrent use of page buffer objects, not for synchronizing independent
989 * access to the underlying pages.
995 PB_TRACE(pb
, "lock", 0);
996 if (atomic_read(&pb
->pb_io_remaining
))
997 blk_run_address_space(pb
->pb_target
->pbr_mapping
);
1000 PB_TRACE(pb
, "locked", 0);
1007 * pagebuf_unlock releases the lock on the buffer object created by
1008 * pagebuf_lock or pagebuf_cond_lock (not any
1009 * pinning of underlying pages created by pagebuf_pin).
1012 pagebuf_unlock( /* unlock buffer */
1013 xfs_buf_t
*pb
) /* buffer to unlock */
1017 PB_TRACE(pb
, "unlock", 0);
1022 * Pinning Buffer Storage in Memory
1028 * pagebuf_pin locks all of the memory represented by a buffer in
1029 * memory. Multiple calls to pagebuf_pin and pagebuf_unpin, for
1030 * the same or different buffers affecting a given page, will
1031 * properly count the number of outstanding "pin" requests. The
1032 * buffer may be released after the pagebuf_pin and a different
1033 * buffer used when calling pagebuf_unpin, if desired.
1034 * pagebuf_pin should be used by the file system when it wants be
1035 * assured that no attempt will be made to force the affected
1036 * memory to disk. It does not assure that a given logical page
1037 * will not be moved to a different physical page.
1043 atomic_inc(&pb
->pb_pin_count
);
1044 PB_TRACE(pb
, "pin", (long)pb
->pb_pin_count
.counter
);
1050 * pagebuf_unpin reverses the locking of memory performed by
1051 * pagebuf_pin. Note that both functions affected the logical
1052 * pages associated with the buffer, not the buffer itself.
1058 if (atomic_dec_and_test(&pb
->pb_pin_count
)) {
1059 wake_up_all(&pb
->pb_waiters
);
1061 PB_TRACE(pb
, "unpin", (long)pb
->pb_pin_count
.counter
);
1068 return atomic_read(&pb
->pb_pin_count
);
1072 * pagebuf_wait_unpin
1074 * pagebuf_wait_unpin waits until all of the memory associated
1075 * with the buffer is not longer locked in memory. It returns
1076 * immediately if none of the affected pages are locked.
1079 _pagebuf_wait_unpin(
1082 DECLARE_WAITQUEUE (wait
, current
);
1084 if (atomic_read(&pb
->pb_pin_count
) == 0)
1087 add_wait_queue(&pb
->pb_waiters
, &wait
);
1089 set_current_state(TASK_UNINTERRUPTIBLE
);
1090 if (atomic_read(&pb
->pb_pin_count
) == 0)
1092 if (atomic_read(&pb
->pb_io_remaining
))
1093 blk_run_address_space(pb
->pb_target
->pbr_mapping
);
1096 remove_wait_queue(&pb
->pb_waiters
, &wait
);
1097 set_current_state(TASK_RUNNING
);
1101 * Buffer Utility Routines
1107 * pagebuf_iodone marks a buffer for which I/O is in progress
1108 * done with respect to that I/O. The pb_iodone routine, if
1109 * present, will be called as a side-effect.
1112 pagebuf_iodone_work(
1115 xfs_buf_t
*bp
= (xfs_buf_t
*)v
;
1118 (*(bp
->pb_iodone
))(bp
);
1119 else if (bp
->pb_flags
& PBF_ASYNC
)
1129 pb
->pb_flags
&= ~(PBF_READ
| PBF_WRITE
);
1130 if (pb
->pb_error
== 0) {
1131 pb
->pb_flags
&= ~(PBF_PARTIAL
| PBF_NONE
);
1134 PB_TRACE(pb
, "iodone", pb
->pb_iodone
);
1136 if ((pb
->pb_iodone
) || (pb
->pb_flags
& PBF_ASYNC
)) {
1138 INIT_WORK(&pb
->pb_iodone_work
, pagebuf_iodone_work
, pb
);
1139 queue_work(dataio
? pagebuf_dataio_workqueue
:
1140 pagebuf_logio_workqueue
, &pb
->pb_iodone_work
);
1142 pagebuf_iodone_work(pb
);
1145 up(&pb
->pb_iodonesema
);
1152 * pagebuf_ioerror sets the error code for a buffer.
1155 pagebuf_ioerror( /* mark/clear buffer error flag */
1156 xfs_buf_t
*pb
, /* buffer to mark */
1157 int error
) /* error to store (0 if none) */
1159 ASSERT(error
>= 0 && error
<= 0xffff);
1160 pb
->pb_error
= (unsigned short)error
;
1161 PB_TRACE(pb
, "ioerror", (unsigned long)error
);
1167 * pagebuf_iostart initiates I/O on a buffer, based on the flags supplied.
1168 * If necessary, it will arrange for any disk space allocation required,
1169 * and it will break up the request if the block mappings require it.
1170 * The pb_iodone routine in the buffer supplied will only be called
1171 * when all of the subsidiary I/O requests, if any, have been completed.
1172 * pagebuf_iostart calls the pagebuf_ioinitiate routine or
1173 * pagebuf_iorequest, if the former routine is not defined, to start
1174 * the I/O on a given low-level request.
1177 pagebuf_iostart( /* start I/O on a buffer */
1178 xfs_buf_t
*pb
, /* buffer to start */
1179 page_buf_flags_t flags
) /* PBF_LOCK, PBF_ASYNC, PBF_READ, */
1180 /* PBF_WRITE, PBF_DELWRI, */
1181 /* PBF_DONT_BLOCK */
1185 PB_TRACE(pb
, "iostart", (unsigned long)flags
);
1187 if (flags
& PBF_DELWRI
) {
1188 pb
->pb_flags
&= ~(PBF_READ
| PBF_WRITE
| PBF_ASYNC
);
1189 pb
->pb_flags
|= flags
& (PBF_DELWRI
| PBF_ASYNC
);
1190 pagebuf_delwri_queue(pb
, 1);
1194 pb
->pb_flags
&= ~(PBF_READ
| PBF_WRITE
| PBF_ASYNC
| PBF_DELWRI
| \
1195 PBF_READ_AHEAD
| _PBF_RUN_QUEUES
);
1196 pb
->pb_flags
|= flags
& (PBF_READ
| PBF_WRITE
| PBF_ASYNC
| \
1197 PBF_READ_AHEAD
| _PBF_RUN_QUEUES
);
1199 BUG_ON(pb
->pb_bn
== XFS_BUF_DADDR_NULL
);
1201 /* For writes allow an alternate strategy routine to precede
1202 * the actual I/O request (which may not be issued at all in
1203 * a shutdown situation, for example).
1205 status
= (flags
& PBF_WRITE
) ?
1206 pagebuf_iostrategy(pb
) : pagebuf_iorequest(pb
);
1208 /* Wait for I/O if we are not an async request.
1209 * Note: async I/O request completion will release the buffer,
1210 * and that can already be done by this point. So using the
1211 * buffer pointer from here on, after async I/O, is invalid.
1213 if (!status
&& !(flags
& PBF_ASYNC
))
1214 status
= pagebuf_iowait(pb
);
1220 * Helper routine for pagebuf_iorequest
1223 STATIC __inline__
int
1227 ASSERT(pb
->pb_flags
& (PBF_READ
|PBF_WRITE
));
1228 if (pb
->pb_flags
& PBF_READ
)
1229 return pb
->pb_locked
;
1233 STATIC __inline__
void
1238 if (atomic_dec_and_test(&pb
->pb_io_remaining
) == 1) {
1240 pagebuf_iodone(pb
, (pb
->pb_flags
& PBF_FS_DATAIOD
), schedule
);
1247 unsigned int bytes_done
,
1250 xfs_buf_t
*pb
= (xfs_buf_t
*)bio
->bi_private
;
1251 unsigned int i
, blocksize
= pb
->pb_target
->pbr_bsize
;
1252 struct bio_vec
*bvec
= bio
->bi_io_vec
;
1257 if (!test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1260 for (i
= 0; i
< bio
->bi_vcnt
; i
++, bvec
++) {
1261 struct page
*page
= bvec
->bv_page
;
1265 } else if (blocksize
== PAGE_CACHE_SIZE
) {
1266 SetPageUptodate(page
);
1267 } else if (!PagePrivate(page
) &&
1268 (pb
->pb_flags
& _PBF_PAGE_CACHE
)) {
1269 set_page_region(page
, bvec
->bv_offset
, bvec
->bv_len
);
1272 if (_pagebuf_iolocked(pb
)) {
1277 _pagebuf_iodone(pb
, 1);
1286 int i
, rw
, map_i
, total_nr_pages
, nr_pages
;
1288 int offset
= pb
->pb_offset
;
1289 int size
= pb
->pb_count_desired
;
1290 sector_t sector
= pb
->pb_bn
;
1291 unsigned int blocksize
= pb
->pb_target
->pbr_bsize
;
1292 int locking
= _pagebuf_iolocked(pb
);
1294 total_nr_pages
= pb
->pb_page_count
;
1297 if (pb
->pb_flags
& _PBF_RUN_QUEUES
) {
1298 pb
->pb_flags
&= ~_PBF_RUN_QUEUES
;
1299 rw
= (pb
->pb_flags
& PBF_READ
) ? READ_SYNC
: WRITE_SYNC
;
1301 rw
= (pb
->pb_flags
& PBF_READ
) ? READ
: WRITE
;
1304 /* Special code path for reading a sub page size pagebuf in --
1305 * we populate up the whole page, and hence the other metadata
1306 * in the same page. This optimization is only valid when the
1307 * filesystem block size and the page size are equal.
1309 if ((pb
->pb_buffer_length
< PAGE_CACHE_SIZE
) &&
1310 (pb
->pb_flags
& PBF_READ
) && locking
&&
1311 (blocksize
== PAGE_CACHE_SIZE
)) {
1312 bio
= bio_alloc(GFP_NOIO
, 1);
1314 bio
->bi_bdev
= pb
->pb_target
->pbr_bdev
;
1315 bio
->bi_sector
= sector
- (offset
>> BBSHIFT
);
1316 bio
->bi_end_io
= bio_end_io_pagebuf
;
1317 bio
->bi_private
= pb
;
1319 bio_add_page(bio
, pb
->pb_pages
[0], PAGE_CACHE_SIZE
, 0);
1322 atomic_inc(&pb
->pb_io_remaining
);
1327 /* Lock down the pages which we need to for the request */
1328 if (locking
&& (pb
->pb_flags
& PBF_WRITE
) && (pb
->pb_locked
== 0)) {
1329 for (i
= 0; size
; i
++) {
1330 int nbytes
= PAGE_CACHE_SIZE
- offset
;
1331 struct page
*page
= pb
->pb_pages
[i
];
1341 offset
= pb
->pb_offset
;
1342 size
= pb
->pb_count_desired
;
1346 atomic_inc(&pb
->pb_io_remaining
);
1347 nr_pages
= BIO_MAX_SECTORS
>> (PAGE_SHIFT
- BBSHIFT
);
1348 if (nr_pages
> total_nr_pages
)
1349 nr_pages
= total_nr_pages
;
1351 bio
= bio_alloc(GFP_NOIO
, nr_pages
);
1352 bio
->bi_bdev
= pb
->pb_target
->pbr_bdev
;
1353 bio
->bi_sector
= sector
;
1354 bio
->bi_end_io
= bio_end_io_pagebuf
;
1355 bio
->bi_private
= pb
;
1357 for (; size
&& nr_pages
; nr_pages
--, map_i
++) {
1358 int nbytes
= PAGE_CACHE_SIZE
- offset
;
1363 if (bio_add_page(bio
, pb
->pb_pages
[map_i
],
1364 nbytes
, offset
) < nbytes
)
1368 sector
+= nbytes
>> BBSHIFT
;
1374 if (likely(bio
->bi_size
)) {
1375 submit_bio(rw
, bio
);
1380 pagebuf_ioerror(pb
, EIO
);
1385 * pagebuf_iorequest -- the core I/O request routine.
1388 pagebuf_iorequest( /* start real I/O */
1389 xfs_buf_t
*pb
) /* buffer to convey to device */
1391 PB_TRACE(pb
, "iorequest", 0);
1393 if (pb
->pb_flags
& PBF_DELWRI
) {
1394 pagebuf_delwri_queue(pb
, 1);
1398 if (pb
->pb_flags
& PBF_WRITE
) {
1399 _pagebuf_wait_unpin(pb
);
1404 /* Set the count to 1 initially, this will stop an I/O
1405 * completion callout which happens before we have started
1406 * all the I/O from calling pagebuf_iodone too early.
1408 atomic_set(&pb
->pb_io_remaining
, 1);
1409 _pagebuf_ioapply(pb
);
1410 _pagebuf_iodone(pb
, 0);
1419 * pagebuf_iowait waits for I/O to complete on the buffer supplied.
1420 * It returns immediately if no I/O is pending. In any case, it returns
1421 * the error code, if any, or 0 if there is no error.
1427 PB_TRACE(pb
, "iowait", 0);
1428 if (atomic_read(&pb
->pb_io_remaining
))
1429 blk_run_address_space(pb
->pb_target
->pbr_mapping
);
1430 down(&pb
->pb_iodonesema
);
1431 PB_TRACE(pb
, "iowaited", (long)pb
->pb_error
);
1432 return pb
->pb_error
;
1442 offset
+= pb
->pb_offset
;
1444 page
= pb
->pb_pages
[offset
>> PAGE_CACHE_SHIFT
];
1445 return (caddr_t
) page_address(page
) + (offset
& (PAGE_CACHE_SIZE
- 1));
1451 * Move data into or out of a buffer.
1455 xfs_buf_t
*pb
, /* buffer to process */
1456 size_t boff
, /* starting buffer offset */
1457 size_t bsize
, /* length to copy */
1458 caddr_t data
, /* data address */
1459 page_buf_rw_t mode
) /* read/write flag */
1461 size_t bend
, cpoff
, csize
;
1464 bend
= boff
+ bsize
;
1465 while (boff
< bend
) {
1466 page
= pb
->pb_pages
[page_buf_btoct(boff
+ pb
->pb_offset
)];
1467 cpoff
= page_buf_poff(boff
+ pb
->pb_offset
);
1468 csize
= min_t(size_t,
1469 PAGE_CACHE_SIZE
-cpoff
, pb
->pb_count_desired
-boff
);
1471 ASSERT(((csize
+ cpoff
) <= PAGE_CACHE_SIZE
));
1475 memset(page_address(page
) + cpoff
, 0, csize
);
1478 memcpy(data
, page_address(page
) + cpoff
, csize
);
1481 memcpy(page_address(page
) + cpoff
, data
, csize
);
1490 * Handling of buftargs.
1494 * Wait for any bufs with callbacks that have been submitted but
1495 * have not yet returned... walk the hash list for the target.
1502 xfs_bufhash_t
*hash
;
1505 for (i
= 0; i
< (1 << btp
->bt_hashshift
); i
++) {
1506 hash
= &btp
->bt_hash
[i
];
1508 spin_lock(&hash
->bh_lock
);
1509 list_for_each_entry_safe(bp
, n
, &hash
->bh_list
, pb_hash_list
) {
1510 ASSERT(btp
== bp
->pb_target
);
1511 if (!(bp
->pb_flags
& PBF_FS_MANAGED
)) {
1512 spin_unlock(&hash
->bh_lock
);
1517 spin_unlock(&hash
->bh_lock
);
1522 * Allocate buffer hash table for a given target.
1523 * For devices containing metadata (i.e. not the log/realtime devices)
1524 * we need to allocate a much larger hash table.
1533 btp
->bt_hashshift
= external
? 3 : 8; /* 8 or 256 buckets */
1534 btp
->bt_hashmask
= (1 << btp
->bt_hashshift
) - 1;
1535 btp
->bt_hash
= kmem_zalloc((1 << btp
->bt_hashshift
) *
1536 sizeof(xfs_bufhash_t
), KM_SLEEP
);
1537 for (i
= 0; i
< (1 << btp
->bt_hashshift
); i
++) {
1538 spin_lock_init(&btp
->bt_hash
[i
].bh_lock
);
1539 INIT_LIST_HEAD(&btp
->bt_hash
[i
].bh_list
);
1547 kmem_free(btp
->bt_hash
,
1548 (1 << btp
->bt_hashshift
) * sizeof(xfs_bufhash_t
));
1549 btp
->bt_hash
= NULL
;
1557 xfs_flush_buftarg(btp
, 1);
1559 xfs_blkdev_put(btp
->pbr_bdev
);
1560 xfs_free_bufhash(btp
);
1561 iput(btp
->pbr_mapping
->host
);
1562 kmem_free(btp
, sizeof(*btp
));
1571 invalidate_bdev(btp
->pbr_bdev
, 1);
1572 truncate_inode_pages(btp
->pbr_mapping
, 0LL);
1576 xfs_setsize_buftarg_flags(
1578 unsigned int blocksize
,
1579 unsigned int sectorsize
,
1582 btp
->pbr_bsize
= blocksize
;
1583 btp
->pbr_sshift
= ffs(sectorsize
) - 1;
1584 btp
->pbr_smask
= sectorsize
- 1;
1586 if (set_blocksize(btp
->pbr_bdev
, sectorsize
)) {
1588 "XFS: Cannot set_blocksize to %u on device %s\n",
1589 sectorsize
, XFS_BUFTARG_NAME(btp
));
1594 (PAGE_CACHE_SIZE
/ BITS_PER_LONG
) > sectorsize
) {
1596 "XFS: %u byte sectors in use on device %s. "
1597 "This is suboptimal; %u or greater is ideal.\n",
1598 sectorsize
, XFS_BUFTARG_NAME(btp
),
1599 (unsigned int)PAGE_CACHE_SIZE
/ BITS_PER_LONG
);
1606 * When allocating the initial buffer target we have not yet
1607 * read in the superblock, so don't know what sized sectors
1608 * are being used is at this early stage. Play safe.
1611 xfs_setsize_buftarg_early(
1613 struct block_device
*bdev
)
1615 return xfs_setsize_buftarg_flags(btp
,
1616 PAGE_CACHE_SIZE
, bdev_hardsect_size(bdev
), 0);
1620 xfs_setsize_buftarg(
1622 unsigned int blocksize
,
1623 unsigned int sectorsize
)
1625 return xfs_setsize_buftarg_flags(btp
, blocksize
, sectorsize
, 1);
1629 xfs_mapping_buftarg(
1631 struct block_device
*bdev
)
1633 struct backing_dev_info
*bdi
;
1634 struct inode
*inode
;
1635 struct address_space
*mapping
;
1636 static struct address_space_operations mapping_aops
= {
1637 .sync_page
= block_sync_page
,
1640 inode
= new_inode(bdev
->bd_inode
->i_sb
);
1643 "XFS: Cannot allocate mapping inode for device %s\n",
1644 XFS_BUFTARG_NAME(btp
));
1647 inode
->i_mode
= S_IFBLK
;
1648 inode
->i_bdev
= bdev
;
1649 inode
->i_rdev
= bdev
->bd_dev
;
1650 bdi
= blk_get_backing_dev_info(bdev
);
1652 bdi
= &default_backing_dev_info
;
1653 mapping
= &inode
->i_data
;
1654 mapping
->a_ops
= &mapping_aops
;
1655 mapping
->backing_dev_info
= bdi
;
1656 mapping_set_gfp_mask(mapping
, GFP_NOFS
);
1657 btp
->pbr_mapping
= mapping
;
1663 struct block_device
*bdev
,
1668 btp
= kmem_zalloc(sizeof(*btp
), KM_SLEEP
);
1670 btp
->pbr_dev
= bdev
->bd_dev
;
1671 btp
->pbr_bdev
= bdev
;
1672 if (xfs_setsize_buftarg_early(btp
, bdev
))
1674 if (xfs_mapping_buftarg(btp
, bdev
))
1676 xfs_alloc_bufhash(btp
, external
);
1680 kmem_free(btp
, sizeof(*btp
));
1686 * Pagebuf delayed write buffer handling
1689 STATIC
LIST_HEAD(pbd_delwrite_queue
);
1690 STATIC
DEFINE_SPINLOCK(pbd_delwrite_lock
);
1693 pagebuf_delwri_queue(
1697 PB_TRACE(pb
, "delwri_q", (long)unlock
);
1698 ASSERT(pb
->pb_flags
& PBF_DELWRI
);
1700 spin_lock(&pbd_delwrite_lock
);
1701 /* If already in the queue, dequeue and place at tail */
1702 if (!list_empty(&pb
->pb_list
)) {
1704 atomic_dec(&pb
->pb_hold
);
1706 list_del(&pb
->pb_list
);
1709 list_add_tail(&pb
->pb_list
, &pbd_delwrite_queue
);
1710 pb
->pb_queuetime
= jiffies
;
1711 spin_unlock(&pbd_delwrite_lock
);
1718 pagebuf_delwri_dequeue(
1723 spin_lock(&pbd_delwrite_lock
);
1724 if ((pb
->pb_flags
& PBF_DELWRI
) && !list_empty(&pb
->pb_list
)) {
1725 list_del_init(&pb
->pb_list
);
1728 pb
->pb_flags
&= ~PBF_DELWRI
;
1729 spin_unlock(&pbd_delwrite_lock
);
1734 PB_TRACE(pb
, "delwri_dq", (long)dequeued
);
1738 pagebuf_runall_queues(
1739 struct workqueue_struct
*queue
)
1741 flush_workqueue(queue
);
1744 /* Defines for pagebuf daemon */
1745 STATIC
DECLARE_COMPLETION(pagebuf_daemon_done
);
1746 STATIC
struct task_struct
*pagebuf_daemon_task
;
1747 STATIC
int pagebuf_daemon_active
;
1748 STATIC
int force_flush
;
1752 pagebuf_daemon_wakeup(
1758 wake_up_process(pagebuf_daemon_task
);
1766 struct list_head tmp
;
1768 xfs_buftarg_t
*target
;
1771 /* Set up the thread */
1772 daemonize("xfsbufd");
1773 current
->flags
|= PF_MEMALLOC
;
1775 pagebuf_daemon_task
= current
;
1776 pagebuf_daemon_active
= 1;
1779 INIT_LIST_HEAD(&tmp
);
1781 try_to_freeze(PF_FREEZE
);
1783 set_current_state(TASK_INTERRUPTIBLE
);
1784 schedule_timeout((xfs_buf_timer_centisecs
* HZ
) / 100);
1786 age
= (xfs_buf_age_centisecs
* HZ
) / 100;
1787 spin_lock(&pbd_delwrite_lock
);
1788 list_for_each_entry_safe(pb
, n
, &pbd_delwrite_queue
, pb_list
) {
1789 PB_TRACE(pb
, "walkq1", (long)pagebuf_ispin(pb
));
1790 ASSERT(pb
->pb_flags
& PBF_DELWRI
);
1792 if (!pagebuf_ispin(pb
) && !pagebuf_cond_lock(pb
)) {
1794 time_before(jiffies
,
1795 pb
->pb_queuetime
+ age
)) {
1800 pb
->pb_flags
&= ~PBF_DELWRI
;
1801 pb
->pb_flags
|= PBF_WRITE
;
1802 list_move(&pb
->pb_list
, &tmp
);
1805 spin_unlock(&pbd_delwrite_lock
);
1807 while (!list_empty(&tmp
)) {
1808 pb
= list_entry(tmp
.next
, xfs_buf_t
, pb_list
);
1809 target
= pb
->pb_target
;
1811 list_del_init(&pb
->pb_list
);
1812 pagebuf_iostrategy(pb
);
1814 blk_run_address_space(target
->pbr_mapping
);
1817 if (as_list_len
> 0)
1821 } while (pagebuf_daemon_active
);
1823 complete_and_exit(&pagebuf_daemon_done
, 0);
1827 * Go through all incore buffers, and release buffers if they belong to
1828 * the given device. This is used in filesystem error handling to
1829 * preserve the consistency of its metadata.
1833 xfs_buftarg_t
*target
,
1836 struct list_head tmp
;
1840 pagebuf_runall_queues(pagebuf_dataio_workqueue
);
1841 pagebuf_runall_queues(pagebuf_logio_workqueue
);
1843 INIT_LIST_HEAD(&tmp
);
1844 spin_lock(&pbd_delwrite_lock
);
1845 list_for_each_entry_safe(pb
, n
, &pbd_delwrite_queue
, pb_list
) {
1847 if (pb
->pb_target
!= target
)
1850 ASSERT(pb
->pb_flags
& PBF_DELWRI
);
1851 PB_TRACE(pb
, "walkq2", (long)pagebuf_ispin(pb
));
1852 if (pagebuf_ispin(pb
)) {
1857 pb
->pb_flags
&= ~PBF_DELWRI
;
1858 pb
->pb_flags
|= PBF_WRITE
;
1859 list_move(&pb
->pb_list
, &tmp
);
1861 spin_unlock(&pbd_delwrite_lock
);
1864 * Dropped the delayed write list lock, now walk the temporary list
1866 list_for_each_entry_safe(pb
, n
, &tmp
, pb_list
) {
1868 pb
->pb_flags
&= ~PBF_ASYNC
;
1870 list_del_init(&pb
->pb_list
);
1873 pagebuf_iostrategy(pb
);
1877 * Remaining list items must be flushed before returning
1879 while (!list_empty(&tmp
)) {
1880 pb
= list_entry(tmp
.next
, xfs_buf_t
, pb_list
);
1882 list_del_init(&pb
->pb_list
);
1888 blk_run_address_space(target
->pbr_mapping
);
1894 pagebuf_daemon_start(void)
1898 pagebuf_logio_workqueue
= create_workqueue("xfslogd");
1899 if (!pagebuf_logio_workqueue
)
1902 pagebuf_dataio_workqueue
= create_workqueue("xfsdatad");
1903 if (!pagebuf_dataio_workqueue
) {
1904 destroy_workqueue(pagebuf_logio_workqueue
);
1908 rval
= kernel_thread(pagebuf_daemon
, NULL
, CLONE_FS
|CLONE_FILES
);
1910 destroy_workqueue(pagebuf_logio_workqueue
);
1911 destroy_workqueue(pagebuf_dataio_workqueue
);
1918 * pagebuf_daemon_stop
1920 * Note: do not mark as __exit, it is called from pagebuf_terminate.
1923 pagebuf_daemon_stop(void)
1925 pagebuf_daemon_active
= 0;
1927 wait_for_completion(&pagebuf_daemon_done
);
1929 destroy_workqueue(pagebuf_logio_workqueue
);
1930 destroy_workqueue(pagebuf_dataio_workqueue
);
1934 * Initialization and Termination
1940 pagebuf_cache
= kmem_cache_create("xfs_buf_t", sizeof(xfs_buf_t
), 0,
1941 SLAB_HWCACHE_ALIGN
, NULL
, NULL
);
1942 if (pagebuf_cache
== NULL
) {
1943 printk("XFS: couldn't init xfs_buf_t cache\n");
1944 pagebuf_terminate();
1948 #ifdef PAGEBUF_TRACE
1949 pagebuf_trace_buf
= ktrace_alloc(PAGEBUF_TRACE_SIZE
, KM_SLEEP
);
1952 pagebuf_daemon_start();
1954 pagebuf_shake
= kmem_shake_register(pagebuf_daemon_wakeup
);
1955 if (pagebuf_shake
== NULL
) {
1956 pagebuf_terminate();
1965 * pagebuf_terminate.
1967 * Note: do not mark as __exit, this is also called from the __init code.
1970 pagebuf_terminate(void)
1972 pagebuf_daemon_stop();
1974 #ifdef PAGEBUF_TRACE
1975 ktrace_free(pagebuf_trace_buf
);
1978 kmem_zone_destroy(pagebuf_cache
);
1979 kmem_shake_deregister(pagebuf_shake
);