2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 #include <linux/stddef.h>
20 #include <linux/errno.h>
21 #include <linux/gfp.h>
22 #include <linux/pagemap.h>
23 #include <linux/init.h>
24 #include <linux/vmalloc.h>
25 #include <linux/bio.h>
26 #include <linux/sysctl.h>
27 #include <linux/proc_fs.h>
28 #include <linux/workqueue.h>
29 #include <linux/percpu.h>
30 #include <linux/blkdev.h>
31 #include <linux/hash.h>
32 #include <linux/kthread.h>
33 #include <linux/migrate.h>
34 #include <linux/backing-dev.h>
35 #include <linux/freezer.h>
36 #include <linux/list_sort.h>
42 #include "xfs_dmapi.h"
43 #include "xfs_mount.h"
44 #include "xfs_trace.h"
46 static kmem_zone_t
*xfs_buf_zone
;
47 STATIC
int xfsbufd(void *);
48 STATIC
int xfsbufd_wakeup(struct shrinker
*, int, gfp_t
);
49 STATIC
void xfs_buf_delwri_queue(xfs_buf_t
*, int);
50 static struct shrinker xfs_buf_shake
= {
51 .shrink
= xfsbufd_wakeup
,
52 .seeks
= DEFAULT_SEEKS
,
55 static struct workqueue_struct
*xfslogd_workqueue
;
56 struct workqueue_struct
*xfsdatad_workqueue
;
57 struct workqueue_struct
*xfsconvertd_workqueue
;
59 #ifdef XFS_BUF_LOCK_TRACKING
60 # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid)
61 # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1)
62 # define XB_GET_OWNER(bp) ((bp)->b_last_holder)
64 # define XB_SET_OWNER(bp) do { } while (0)
65 # define XB_CLEAR_OWNER(bp) do { } while (0)
66 # define XB_GET_OWNER(bp) do { } while (0)
69 #define xb_to_gfp(flags) \
70 ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \
71 ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN)
73 #define xb_to_km(flags) \
74 (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP)
76 #define xfs_buf_allocate(flags) \
77 kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags))
78 #define xfs_buf_deallocate(bp) \
79 kmem_zone_free(xfs_buf_zone, (bp));
86 * Return true if the buffer is vmapped.
88 * The XBF_MAPPED flag is set if the buffer should be mapped, but the
89 * code is clever enough to know it doesn't have to map a single page,
90 * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1.
92 return (bp
->b_flags
& XBF_MAPPED
) && bp
->b_page_count
> 1;
99 return (bp
->b_page_count
* PAGE_SIZE
) - bp
->b_offset
;
103 * Page Region interfaces.
105 * For pages in filesystems where the blocksize is smaller than the
106 * pagesize, we use the page->private field (long) to hold a bitmap
107 * of uptodate regions within the page.
109 * Each such region is "bytes per page / bits per long" bytes long.
111 * NBPPR == number-of-bytes-per-page-region
112 * BTOPR == bytes-to-page-region (rounded up)
113 * BTOPRT == bytes-to-page-region-truncated (rounded down)
115 #if (BITS_PER_LONG == 32)
116 #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */
117 #elif (BITS_PER_LONG == 64)
118 #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */
120 #error BITS_PER_LONG must be 32 or 64
122 #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG)
123 #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT)
124 #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT))
134 first
= BTOPR(offset
);
135 final
= BTOPRT(offset
+ length
- 1);
136 first
= min(first
, final
);
139 mask
<<= BITS_PER_LONG
- (final
- first
);
140 mask
>>= BITS_PER_LONG
- (final
);
142 ASSERT(offset
+ length
<= PAGE_CACHE_SIZE
);
143 ASSERT((final
- first
) < BITS_PER_LONG
&& (final
- first
) >= 0);
154 set_page_private(page
,
155 page_private(page
) | page_region_mask(offset
, length
));
156 if (page_private(page
) == ~0UL)
157 SetPageUptodate(page
);
166 unsigned long mask
= page_region_mask(offset
, length
);
168 return (mask
&& (page_private(page
) & mask
) == mask
);
172 * Internal xfs_buf_t object manipulation
178 xfs_buftarg_t
*target
,
179 xfs_off_t range_base
,
181 xfs_buf_flags_t flags
)
184 * We don't want certain flags to appear in b_flags.
186 flags
&= ~(XBF_LOCK
|XBF_MAPPED
|XBF_DONT_BLOCK
|XBF_READ_AHEAD
);
188 memset(bp
, 0, sizeof(xfs_buf_t
));
189 atomic_set(&bp
->b_hold
, 1);
190 init_completion(&bp
->b_iowait
);
191 INIT_LIST_HEAD(&bp
->b_list
);
192 INIT_LIST_HEAD(&bp
->b_hash_list
);
193 init_MUTEX_LOCKED(&bp
->b_sema
); /* held, no waiters */
195 bp
->b_target
= target
;
196 bp
->b_file_offset
= range_base
;
198 * Set buffer_length and count_desired to the same value initially.
199 * I/O routines should use count_desired, which will be the same in
200 * most cases but may be reset (e.g. XFS recovery).
202 bp
->b_buffer_length
= bp
->b_count_desired
= range_length
;
204 bp
->b_bn
= XFS_BUF_DADDR_NULL
;
205 atomic_set(&bp
->b_pin_count
, 0);
206 init_waitqueue_head(&bp
->b_waiters
);
208 XFS_STATS_INC(xb_create
);
210 trace_xfs_buf_init(bp
, _RET_IP_
);
214 * Allocate a page array capable of holding a specified number
215 * of pages, and point the page buf at it.
221 xfs_buf_flags_t flags
)
223 /* Make sure that we have a page list */
224 if (bp
->b_pages
== NULL
) {
225 bp
->b_offset
= xfs_buf_poff(bp
->b_file_offset
);
226 bp
->b_page_count
= page_count
;
227 if (page_count
<= XB_PAGES
) {
228 bp
->b_pages
= bp
->b_page_array
;
230 bp
->b_pages
= kmem_alloc(sizeof(struct page
*) *
231 page_count
, xb_to_km(flags
));
232 if (bp
->b_pages
== NULL
)
235 memset(bp
->b_pages
, 0, sizeof(struct page
*) * page_count
);
241 * Frees b_pages if it was allocated.
247 if (bp
->b_pages
!= bp
->b_page_array
) {
248 kmem_free(bp
->b_pages
);
254 * Releases the specified buffer.
256 * The modification state of any associated pages is left unchanged.
257 * The buffer most not be on any hash - use xfs_buf_rele instead for
258 * hashed and refcounted buffers
264 trace_xfs_buf_free(bp
, _RET_IP_
);
266 ASSERT(list_empty(&bp
->b_hash_list
));
268 if (bp
->b_flags
& (_XBF_PAGE_CACHE
|_XBF_PAGES
)) {
271 if (xfs_buf_is_vmapped(bp
))
272 vm_unmap_ram(bp
->b_addr
- bp
->b_offset
,
275 for (i
= 0; i
< bp
->b_page_count
; i
++) {
276 struct page
*page
= bp
->b_pages
[i
];
278 if (bp
->b_flags
& _XBF_PAGE_CACHE
)
279 ASSERT(!PagePrivate(page
));
280 page_cache_release(page
);
283 _xfs_buf_free_pages(bp
);
284 xfs_buf_deallocate(bp
);
288 * Finds all pages for buffer in question and builds it's page list.
291 _xfs_buf_lookup_pages(
295 struct address_space
*mapping
= bp
->b_target
->bt_mapping
;
296 size_t blocksize
= bp
->b_target
->bt_bsize
;
297 size_t size
= bp
->b_count_desired
;
298 size_t nbytes
, offset
;
299 gfp_t gfp_mask
= xb_to_gfp(flags
);
300 unsigned short page_count
, i
;
305 end
= bp
->b_file_offset
+ bp
->b_buffer_length
;
306 page_count
= xfs_buf_btoc(end
) - xfs_buf_btoct(bp
->b_file_offset
);
308 error
= _xfs_buf_get_pages(bp
, page_count
, flags
);
311 bp
->b_flags
|= _XBF_PAGE_CACHE
;
313 offset
= bp
->b_offset
;
314 first
= bp
->b_file_offset
>> PAGE_CACHE_SHIFT
;
316 for (i
= 0; i
< bp
->b_page_count
; i
++) {
321 page
= find_or_create_page(mapping
, first
+ i
, gfp_mask
);
322 if (unlikely(page
== NULL
)) {
323 if (flags
& XBF_READ_AHEAD
) {
324 bp
->b_page_count
= i
;
325 for (i
= 0; i
< bp
->b_page_count
; i
++)
326 unlock_page(bp
->b_pages
[i
]);
331 * This could deadlock.
333 * But until all the XFS lowlevel code is revamped to
334 * handle buffer allocation failures we can't do much.
336 if (!(++retries
% 100))
338 "XFS: possible memory allocation "
339 "deadlock in %s (mode:0x%x)\n",
342 XFS_STATS_INC(xb_page_retries
);
343 xfsbufd_wakeup(NULL
, 0, gfp_mask
);
344 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
348 XFS_STATS_INC(xb_page_found
);
350 nbytes
= min_t(size_t, size
, PAGE_CACHE_SIZE
- offset
);
353 ASSERT(!PagePrivate(page
));
354 if (!PageUptodate(page
)) {
356 if (blocksize
>= PAGE_CACHE_SIZE
) {
357 if (flags
& XBF_READ
)
358 bp
->b_flags
|= _XBF_PAGE_LOCKED
;
359 } else if (!PagePrivate(page
)) {
360 if (test_page_region(page
, offset
, nbytes
))
365 bp
->b_pages
[i
] = page
;
369 if (!(bp
->b_flags
& _XBF_PAGE_LOCKED
)) {
370 for (i
= 0; i
< bp
->b_page_count
; i
++)
371 unlock_page(bp
->b_pages
[i
]);
374 if (page_count
== bp
->b_page_count
)
375 bp
->b_flags
|= XBF_DONE
;
381 * Map buffer into kernel address-space if nessecary.
388 /* A single page buffer is always mappable */
389 if (bp
->b_page_count
== 1) {
390 bp
->b_addr
= page_address(bp
->b_pages
[0]) + bp
->b_offset
;
391 bp
->b_flags
|= XBF_MAPPED
;
392 } else if (flags
& XBF_MAPPED
) {
393 bp
->b_addr
= vm_map_ram(bp
->b_pages
, bp
->b_page_count
,
395 if (unlikely(bp
->b_addr
== NULL
))
397 bp
->b_addr
+= bp
->b_offset
;
398 bp
->b_flags
|= XBF_MAPPED
;
405 * Finding and Reading Buffers
409 * Look up, and creates if absent, a lockable buffer for
410 * a given range of an inode. The buffer is returned
411 * locked. If other overlapping buffers exist, they are
412 * released before the new buffer is created and locked,
413 * which may imply that this call will block until those buffers
414 * are unlocked. No I/O is implied by this call.
418 xfs_buftarg_t
*btp
, /* block device target */
419 xfs_off_t ioff
, /* starting offset of range */
420 size_t isize
, /* length of range */
421 xfs_buf_flags_t flags
,
424 xfs_off_t range_base
;
429 range_base
= (ioff
<< BBSHIFT
);
430 range_length
= (isize
<< BBSHIFT
);
432 /* Check for IOs smaller than the sector size / not sector aligned */
433 ASSERT(!(range_length
< (1 << btp
->bt_sshift
)));
434 ASSERT(!(range_base
& (xfs_off_t
)btp
->bt_smask
));
436 hash
= &btp
->bt_hash
[hash_long((unsigned long)ioff
, btp
->bt_hashshift
)];
438 spin_lock(&hash
->bh_lock
);
440 list_for_each_entry_safe(bp
, n
, &hash
->bh_list
, b_hash_list
) {
441 ASSERT(btp
== bp
->b_target
);
442 if (bp
->b_file_offset
== range_base
&&
443 bp
->b_buffer_length
== range_length
) {
445 * If we look at something, bring it to the
446 * front of the list for next time.
448 atomic_inc(&bp
->b_hold
);
449 list_move(&bp
->b_hash_list
, &hash
->bh_list
);
456 _xfs_buf_initialize(new_bp
, btp
, range_base
,
457 range_length
, flags
);
458 new_bp
->b_hash
= hash
;
459 list_add(&new_bp
->b_hash_list
, &hash
->bh_list
);
461 XFS_STATS_INC(xb_miss_locked
);
464 spin_unlock(&hash
->bh_lock
);
468 spin_unlock(&hash
->bh_lock
);
470 /* Attempt to get the semaphore without sleeping,
471 * if this does not work then we need to drop the
472 * spinlock and do a hard attempt on the semaphore.
474 if (down_trylock(&bp
->b_sema
)) {
475 if (!(flags
& XBF_TRYLOCK
)) {
476 /* wait for buffer ownership */
478 XFS_STATS_INC(xb_get_locked_waited
);
480 /* We asked for a trylock and failed, no need
481 * to look at file offset and length here, we
482 * know that this buffer at least overlaps our
483 * buffer and is locked, therefore our buffer
484 * either does not exist, or is this buffer.
487 XFS_STATS_INC(xb_busy_locked
);
495 if (bp
->b_flags
& XBF_STALE
) {
496 ASSERT((bp
->b_flags
& _XBF_DELWRI_Q
) == 0);
497 bp
->b_flags
&= XBF_MAPPED
;
500 trace_xfs_buf_find(bp
, flags
, _RET_IP_
);
501 XFS_STATS_INC(xb_get_locked
);
506 * Assembles a buffer covering the specified range.
507 * Storage in memory for all portions of the buffer will be allocated,
508 * although backing storage may not be.
512 xfs_buftarg_t
*target
,/* target for buffer */
513 xfs_off_t ioff
, /* starting offset of range */
514 size_t isize
, /* length of range */
515 xfs_buf_flags_t flags
)
517 xfs_buf_t
*bp
, *new_bp
;
520 new_bp
= xfs_buf_allocate(flags
);
521 if (unlikely(!new_bp
))
524 bp
= _xfs_buf_find(target
, ioff
, isize
, flags
, new_bp
);
526 error
= _xfs_buf_lookup_pages(bp
, flags
);
530 xfs_buf_deallocate(new_bp
);
531 if (unlikely(bp
== NULL
))
535 for (i
= 0; i
< bp
->b_page_count
; i
++)
536 mark_page_accessed(bp
->b_pages
[i
]);
538 if (!(bp
->b_flags
& XBF_MAPPED
)) {
539 error
= _xfs_buf_map_pages(bp
, flags
);
540 if (unlikely(error
)) {
541 printk(KERN_WARNING
"%s: failed to map pages\n",
547 XFS_STATS_INC(xb_get
);
550 * Always fill in the block number now, the mapped cases can do
551 * their own overlay of this later.
554 bp
->b_count_desired
= bp
->b_buffer_length
;
556 trace_xfs_buf_get(bp
, flags
, _RET_IP_
);
560 if (flags
& (XBF_LOCK
| XBF_TRYLOCK
))
569 xfs_buf_flags_t flags
)
573 ASSERT(!(flags
& (XBF_DELWRI
|XBF_WRITE
)));
574 ASSERT(bp
->b_bn
!= XFS_BUF_DADDR_NULL
);
576 bp
->b_flags
&= ~(XBF_WRITE
| XBF_ASYNC
| XBF_DELWRI
| \
577 XBF_READ_AHEAD
| _XBF_RUN_QUEUES
);
578 bp
->b_flags
|= flags
& (XBF_READ
| XBF_ASYNC
| \
579 XBF_READ_AHEAD
| _XBF_RUN_QUEUES
);
581 status
= xfs_buf_iorequest(bp
);
582 if (!status
&& !(flags
& XBF_ASYNC
))
583 status
= xfs_buf_iowait(bp
);
589 xfs_buftarg_t
*target
,
592 xfs_buf_flags_t flags
)
598 bp
= xfs_buf_get(target
, ioff
, isize
, flags
);
600 trace_xfs_buf_read(bp
, flags
, _RET_IP_
);
602 if (!XFS_BUF_ISDONE(bp
)) {
603 XFS_STATS_INC(xb_get_read
);
604 _xfs_buf_read(bp
, flags
);
605 } else if (flags
& XBF_ASYNC
) {
607 * Read ahead call which is already satisfied,
612 /* We do not want read in the flags */
613 bp
->b_flags
&= ~XBF_READ
;
620 if (flags
& (XBF_LOCK
| XBF_TRYLOCK
))
627 * If we are not low on memory then do the readahead in a deadlock
632 xfs_buftarg_t
*target
,
635 xfs_buf_flags_t flags
)
637 struct backing_dev_info
*bdi
;
639 bdi
= target
->bt_mapping
->backing_dev_info
;
640 if (bdi_read_congested(bdi
))
643 flags
|= (XBF_TRYLOCK
|XBF_ASYNC
|XBF_READ_AHEAD
);
644 xfs_buf_read(target
, ioff
, isize
, flags
);
650 xfs_buftarg_t
*target
)
654 bp
= xfs_buf_allocate(0);
656 _xfs_buf_initialize(bp
, target
, 0, len
, 0);
660 static inline struct page
*
664 if ((!is_vmalloc_addr(addr
))) {
665 return virt_to_page(addr
);
667 return vmalloc_to_page(addr
);
672 xfs_buf_associate_memory(
679 unsigned long pageaddr
;
680 unsigned long offset
;
684 pageaddr
= (unsigned long)mem
& PAGE_CACHE_MASK
;
685 offset
= (unsigned long)mem
- pageaddr
;
686 buflen
= PAGE_CACHE_ALIGN(len
+ offset
);
687 page_count
= buflen
>> PAGE_CACHE_SHIFT
;
689 /* Free any previous set of page pointers */
691 _xfs_buf_free_pages(bp
);
696 rval
= _xfs_buf_get_pages(bp
, page_count
, XBF_DONT_BLOCK
);
700 bp
->b_offset
= offset
;
702 for (i
= 0; i
< bp
->b_page_count
; i
++) {
703 bp
->b_pages
[i
] = mem_to_page((void *)pageaddr
);
704 pageaddr
+= PAGE_CACHE_SIZE
;
707 bp
->b_count_desired
= len
;
708 bp
->b_buffer_length
= buflen
;
709 bp
->b_flags
|= XBF_MAPPED
;
710 bp
->b_flags
&= ~_XBF_PAGE_LOCKED
;
718 xfs_buftarg_t
*target
)
720 unsigned long page_count
= PAGE_ALIGN(len
) >> PAGE_SHIFT
;
724 bp
= xfs_buf_allocate(0);
725 if (unlikely(bp
== NULL
))
727 _xfs_buf_initialize(bp
, target
, 0, len
, 0);
729 error
= _xfs_buf_get_pages(bp
, page_count
, 0);
733 for (i
= 0; i
< page_count
; i
++) {
734 bp
->b_pages
[i
] = alloc_page(GFP_KERNEL
);
738 bp
->b_flags
|= _XBF_PAGES
;
740 error
= _xfs_buf_map_pages(bp
, XBF_MAPPED
);
741 if (unlikely(error
)) {
742 printk(KERN_WARNING
"%s: failed to map pages\n",
749 trace_xfs_buf_get_noaddr(bp
, _RET_IP_
);
754 __free_page(bp
->b_pages
[i
]);
755 _xfs_buf_free_pages(bp
);
757 xfs_buf_deallocate(bp
);
763 * Increment reference count on buffer, to hold the buffer concurrently
764 * with another thread which may release (free) the buffer asynchronously.
765 * Must hold the buffer already to call this function.
771 trace_xfs_buf_hold(bp
, _RET_IP_
);
772 atomic_inc(&bp
->b_hold
);
776 * Releases a hold on the specified buffer. If the
777 * the hold count is 1, calls xfs_buf_free.
783 xfs_bufhash_t
*hash
= bp
->b_hash
;
785 trace_xfs_buf_rele(bp
, _RET_IP_
);
787 if (unlikely(!hash
)) {
788 ASSERT(!bp
->b_relse
);
789 if (atomic_dec_and_test(&bp
->b_hold
))
794 ASSERT(atomic_read(&bp
->b_hold
) > 0);
795 if (atomic_dec_and_lock(&bp
->b_hold
, &hash
->bh_lock
)) {
797 atomic_inc(&bp
->b_hold
);
798 spin_unlock(&hash
->bh_lock
);
799 (*(bp
->b_relse
)) (bp
);
800 } else if (bp
->b_flags
& XBF_FS_MANAGED
) {
801 spin_unlock(&hash
->bh_lock
);
803 ASSERT(!(bp
->b_flags
& (XBF_DELWRI
|_XBF_DELWRI_Q
)));
804 list_del_init(&bp
->b_hash_list
);
805 spin_unlock(&hash
->bh_lock
);
813 * Mutual exclusion on buffers. Locking model:
815 * Buffers associated with inodes for which buffer locking
816 * is not enabled are not protected by semaphores, and are
817 * assumed to be exclusively owned by the caller. There is a
818 * spinlock in the buffer, used by the caller when concurrent
819 * access is possible.
823 * Locks a buffer object, if it is not already locked.
824 * Note that this in no way locks the underlying pages, so it is only
825 * useful for synchronizing concurrent use of buffer objects, not for
826 * synchronizing independent access to the underlying pages.
834 locked
= down_trylock(&bp
->b_sema
) == 0;
838 trace_xfs_buf_cond_lock(bp
, _RET_IP_
);
839 return locked
? 0 : -EBUSY
;
846 return bp
->b_sema
.count
;
850 * Locks a buffer object.
851 * Note that this in no way locks the underlying pages, so it is only
852 * useful for synchronizing concurrent use of buffer objects, not for
853 * synchronizing independent access to the underlying pages.
855 * If we come across a stale, pinned, locked buffer, we know that we
856 * are being asked to lock a buffer that has been reallocated. Because
857 * it is pinned, we know that the log has not been pushed to disk and
858 * hence it will still be locked. Rather than sleeping until someone
859 * else pushes the log, push it ourselves before trying to get the lock.
865 trace_xfs_buf_lock(bp
, _RET_IP_
);
867 if (atomic_read(&bp
->b_pin_count
) && (bp
->b_flags
& XBF_STALE
))
868 xfs_log_force(bp
->b_mount
, 0);
869 if (atomic_read(&bp
->b_io_remaining
))
870 blk_run_address_space(bp
->b_target
->bt_mapping
);
874 trace_xfs_buf_lock_done(bp
, _RET_IP_
);
878 * Releases the lock on the buffer object.
879 * If the buffer is marked delwri but is not queued, do so before we
880 * unlock the buffer as we need to set flags correctly. We also need to
881 * take a reference for the delwri queue because the unlocker is going to
882 * drop their's and they don't know we just queued it.
888 if ((bp
->b_flags
& (XBF_DELWRI
|_XBF_DELWRI_Q
)) == XBF_DELWRI
) {
889 atomic_inc(&bp
->b_hold
);
890 bp
->b_flags
|= XBF_ASYNC
;
891 xfs_buf_delwri_queue(bp
, 0);
897 trace_xfs_buf_unlock(bp
, _RET_IP_
);
902 * Pinning Buffer Storage in Memory
903 * Ensure that no attempt to force a buffer to disk will succeed.
909 trace_xfs_buf_pin(bp
, _RET_IP_
);
910 atomic_inc(&bp
->b_pin_count
);
917 trace_xfs_buf_unpin(bp
, _RET_IP_
);
919 if (atomic_dec_and_test(&bp
->b_pin_count
))
920 wake_up_all(&bp
->b_waiters
);
927 return atomic_read(&bp
->b_pin_count
);
934 DECLARE_WAITQUEUE (wait
, current
);
936 if (atomic_read(&bp
->b_pin_count
) == 0)
939 add_wait_queue(&bp
->b_waiters
, &wait
);
941 set_current_state(TASK_UNINTERRUPTIBLE
);
942 if (atomic_read(&bp
->b_pin_count
) == 0)
944 if (atomic_read(&bp
->b_io_remaining
))
945 blk_run_address_space(bp
->b_target
->bt_mapping
);
948 remove_wait_queue(&bp
->b_waiters
, &wait
);
949 set_current_state(TASK_RUNNING
);
953 * Buffer Utility Routines
958 struct work_struct
*work
)
961 container_of(work
, xfs_buf_t
, b_iodone_work
);
964 * We can get an EOPNOTSUPP to ordered writes. Here we clear the
965 * ordered flag and reissue them. Because we can't tell the higher
966 * layers directly that they should not issue ordered I/O anymore, they
967 * need to check if the _XFS_BARRIER_FAILED flag was set during I/O completion.
969 if ((bp
->b_error
== EOPNOTSUPP
) &&
970 (bp
->b_flags
& (XBF_ORDERED
|XBF_ASYNC
)) == (XBF_ORDERED
|XBF_ASYNC
)) {
971 trace_xfs_buf_ordered_retry(bp
, _RET_IP_
);
972 bp
->b_flags
&= ~XBF_ORDERED
;
973 bp
->b_flags
|= _XFS_BARRIER_FAILED
;
974 xfs_buf_iorequest(bp
);
975 } else if (bp
->b_iodone
)
976 (*(bp
->b_iodone
))(bp
);
977 else if (bp
->b_flags
& XBF_ASYNC
)
986 trace_xfs_buf_iodone(bp
, _RET_IP_
);
988 bp
->b_flags
&= ~(XBF_READ
| XBF_WRITE
| XBF_READ_AHEAD
);
989 if (bp
->b_error
== 0)
990 bp
->b_flags
|= XBF_DONE
;
992 if ((bp
->b_iodone
) || (bp
->b_flags
& XBF_ASYNC
)) {
994 INIT_WORK(&bp
->b_iodone_work
, xfs_buf_iodone_work
);
995 queue_work(xfslogd_workqueue
, &bp
->b_iodone_work
);
997 xfs_buf_iodone_work(&bp
->b_iodone_work
);
1000 complete(&bp
->b_iowait
);
1009 ASSERT(error
>= 0 && error
<= 0xffff);
1010 bp
->b_error
= (unsigned short)error
;
1011 trace_xfs_buf_ioerror(bp
, error
, _RET_IP_
);
1016 struct xfs_mount
*mp
,
1021 bp
->b_strat
= xfs_bdstrat_cb
;
1023 bp
->b_flags
|= XBF_WRITE
;
1024 bp
->b_flags
&= ~(XBF_ASYNC
| XBF_READ
);
1026 xfs_buf_delwri_dequeue(bp
);
1027 xfs_buf_iostrategy(bp
);
1029 error
= xfs_buf_iowait(bp
);
1031 xfs_force_shutdown(mp
, SHUTDOWN_META_IO_ERROR
);
1041 trace_xfs_buf_bdwrite(bp
, _RET_IP_
);
1043 bp
->b_strat
= xfs_bdstrat_cb
;
1046 bp
->b_flags
&= ~XBF_READ
;
1047 bp
->b_flags
|= (XBF_DELWRI
| XBF_ASYNC
);
1049 xfs_buf_delwri_queue(bp
, 1);
1053 * Called when we want to stop a buffer from getting written or read.
1054 * We attach the EIO error, muck with its flags, and call biodone
1055 * so that the proper iodone callbacks get called.
1061 #ifdef XFSERRORDEBUG
1062 ASSERT(XFS_BUF_ISREAD(bp
) || bp
->b_iodone
);
1066 * No need to wait until the buffer is unpinned, we aren't flushing it.
1068 XFS_BUF_ERROR(bp
, EIO
);
1071 * We're calling biodone, so delete XBF_DONE flag.
1074 XFS_BUF_UNDELAYWRITE(bp
);
1078 XFS_BUF_CLR_BDSTRAT_FUNC(bp
);
1085 * Same as xfs_bioerror, except that we are releasing the buffer
1086 * here ourselves, and avoiding the biodone call.
1087 * This is meant for userdata errors; metadata bufs come with
1088 * iodone functions attached, so that we can track down errors.
1094 int64_t fl
= XFS_BUF_BFLAGS(bp
);
1096 * No need to wait until the buffer is unpinned.
1097 * We aren't flushing it.
1099 * chunkhold expects B_DONE to be set, whether
1100 * we actually finish the I/O or not. We don't want to
1101 * change that interface.
1104 XFS_BUF_UNDELAYWRITE(bp
);
1107 XFS_BUF_CLR_IODONE_FUNC(bp
);
1108 XFS_BUF_CLR_BDSTRAT_FUNC(bp
);
1109 if (!(fl
& XBF_ASYNC
)) {
1111 * Mark b_error and B_ERROR _both_.
1112 * Lot's of chunkcache code assumes that.
1113 * There's no reason to mark error for
1116 XFS_BUF_ERROR(bp
, EIO
);
1117 XFS_BUF_FINISH_IOWAIT(bp
);
1127 * All xfs metadata buffers except log state machine buffers
1128 * get this attached as their b_bdstrat callback function.
1129 * This is so that we can catch a buffer
1130 * after prematurely unpinning it to forcibly shutdown the filesystem.
1136 if (XFS_FORCED_SHUTDOWN(bp
->b_mount
)) {
1137 trace_xfs_bdstrat_shut(bp
, _RET_IP_
);
1139 * Metadata write that didn't get logged but
1140 * written delayed anyway. These aren't associated
1141 * with a transaction, and can be ignored.
1143 if (!bp
->b_iodone
&& !XFS_BUF_ISREAD(bp
))
1144 return xfs_bioerror_relse(bp
);
1146 return xfs_bioerror(bp
);
1149 xfs_buf_iorequest(bp
);
1154 * Wrapper around bdstrat so that we can stop data from going to disk in case
1155 * we are shutting down the filesystem. Typically user data goes thru this
1156 * path; one of the exceptions is the superblock.
1160 struct xfs_mount
*mp
,
1163 if (XFS_FORCED_SHUTDOWN(mp
)) {
1164 trace_xfs_bdstrat_shut(bp
, _RET_IP_
);
1165 xfs_bioerror_relse(bp
);
1169 xfs_buf_iorequest(bp
);
1177 if (atomic_dec_and_test(&bp
->b_io_remaining
) == 1) {
1178 bp
->b_flags
&= ~_XBF_PAGE_LOCKED
;
1179 xfs_buf_ioend(bp
, schedule
);
1188 xfs_buf_t
*bp
= (xfs_buf_t
*)bio
->bi_private
;
1189 unsigned int blocksize
= bp
->b_target
->bt_bsize
;
1190 struct bio_vec
*bvec
= bio
->bi_io_vec
+ bio
->bi_vcnt
- 1;
1192 xfs_buf_ioerror(bp
, -error
);
1194 if (!error
&& xfs_buf_is_vmapped(bp
) && (bp
->b_flags
& XBF_READ
))
1195 invalidate_kernel_vmap_range(bp
->b_addr
, xfs_buf_vmap_len(bp
));
1198 struct page
*page
= bvec
->bv_page
;
1200 ASSERT(!PagePrivate(page
));
1201 if (unlikely(bp
->b_error
)) {
1202 if (bp
->b_flags
& XBF_READ
)
1203 ClearPageUptodate(page
);
1204 } else if (blocksize
>= PAGE_CACHE_SIZE
) {
1205 SetPageUptodate(page
);
1206 } else if (!PagePrivate(page
) &&
1207 (bp
->b_flags
& _XBF_PAGE_CACHE
)) {
1208 set_page_region(page
, bvec
->bv_offset
, bvec
->bv_len
);
1211 if (--bvec
>= bio
->bi_io_vec
)
1212 prefetchw(&bvec
->bv_page
->flags
);
1214 if (bp
->b_flags
& _XBF_PAGE_LOCKED
)
1216 } while (bvec
>= bio
->bi_io_vec
);
1218 _xfs_buf_ioend(bp
, 1);
1226 int rw
, map_i
, total_nr_pages
, nr_pages
;
1228 int offset
= bp
->b_offset
;
1229 int size
= bp
->b_count_desired
;
1230 sector_t sector
= bp
->b_bn
;
1231 unsigned int blocksize
= bp
->b_target
->bt_bsize
;
1233 total_nr_pages
= bp
->b_page_count
;
1236 if (bp
->b_flags
& XBF_ORDERED
) {
1237 ASSERT(!(bp
->b_flags
& XBF_READ
));
1239 } else if (bp
->b_flags
& XBF_LOG_BUFFER
) {
1240 ASSERT(!(bp
->b_flags
& XBF_READ_AHEAD
));
1241 bp
->b_flags
&= ~_XBF_RUN_QUEUES
;
1242 rw
= (bp
->b_flags
& XBF_WRITE
) ? WRITE_SYNC
: READ_SYNC
;
1243 } else if (bp
->b_flags
& _XBF_RUN_QUEUES
) {
1244 ASSERT(!(bp
->b_flags
& XBF_READ_AHEAD
));
1245 bp
->b_flags
&= ~_XBF_RUN_QUEUES
;
1246 rw
= (bp
->b_flags
& XBF_WRITE
) ? WRITE_META
: READ_META
;
1248 rw
= (bp
->b_flags
& XBF_WRITE
) ? WRITE
:
1249 (bp
->b_flags
& XBF_READ_AHEAD
) ? READA
: READ
;
1252 /* Special code path for reading a sub page size buffer in --
1253 * we populate up the whole page, and hence the other metadata
1254 * in the same page. This optimization is only valid when the
1255 * filesystem block size is not smaller than the page size.
1257 if ((bp
->b_buffer_length
< PAGE_CACHE_SIZE
) &&
1258 ((bp
->b_flags
& (XBF_READ
|_XBF_PAGE_LOCKED
)) ==
1259 (XBF_READ
|_XBF_PAGE_LOCKED
)) &&
1260 (blocksize
>= PAGE_CACHE_SIZE
)) {
1261 bio
= bio_alloc(GFP_NOIO
, 1);
1263 bio
->bi_bdev
= bp
->b_target
->bt_bdev
;
1264 bio
->bi_sector
= sector
- (offset
>> BBSHIFT
);
1265 bio
->bi_end_io
= xfs_buf_bio_end_io
;
1266 bio
->bi_private
= bp
;
1268 bio_add_page(bio
, bp
->b_pages
[0], PAGE_CACHE_SIZE
, 0);
1271 atomic_inc(&bp
->b_io_remaining
);
1277 atomic_inc(&bp
->b_io_remaining
);
1278 nr_pages
= BIO_MAX_SECTORS
>> (PAGE_SHIFT
- BBSHIFT
);
1279 if (nr_pages
> total_nr_pages
)
1280 nr_pages
= total_nr_pages
;
1282 bio
= bio_alloc(GFP_NOIO
, nr_pages
);
1283 bio
->bi_bdev
= bp
->b_target
->bt_bdev
;
1284 bio
->bi_sector
= sector
;
1285 bio
->bi_end_io
= xfs_buf_bio_end_io
;
1286 bio
->bi_private
= bp
;
1288 for (; size
&& nr_pages
; nr_pages
--, map_i
++) {
1289 int rbytes
, nbytes
= PAGE_CACHE_SIZE
- offset
;
1294 rbytes
= bio_add_page(bio
, bp
->b_pages
[map_i
], nbytes
, offset
);
1295 if (rbytes
< nbytes
)
1299 sector
+= nbytes
>> BBSHIFT
;
1305 if (likely(bio
->bi_size
)) {
1306 if (xfs_buf_is_vmapped(bp
)) {
1307 flush_kernel_vmap_range(bp
->b_addr
,
1308 xfs_buf_vmap_len(bp
));
1310 submit_bio(rw
, bio
);
1315 xfs_buf_ioerror(bp
, EIO
);
1323 trace_xfs_buf_iorequest(bp
, _RET_IP_
);
1325 if (bp
->b_flags
& XBF_DELWRI
) {
1326 xfs_buf_delwri_queue(bp
, 1);
1330 if (bp
->b_flags
& XBF_WRITE
) {
1331 xfs_buf_wait_unpin(bp
);
1336 /* Set the count to 1 initially, this will stop an I/O
1337 * completion callout which happens before we have started
1338 * all the I/O from calling xfs_buf_ioend too early.
1340 atomic_set(&bp
->b_io_remaining
, 1);
1341 _xfs_buf_ioapply(bp
);
1342 _xfs_buf_ioend(bp
, 0);
1349 * Waits for I/O to complete on the buffer supplied.
1350 * It returns immediately if no I/O is pending.
1351 * It returns the I/O error code, if any, or 0 if there was no error.
1357 trace_xfs_buf_iowait(bp
, _RET_IP_
);
1359 if (atomic_read(&bp
->b_io_remaining
))
1360 blk_run_address_space(bp
->b_target
->bt_mapping
);
1361 wait_for_completion(&bp
->b_iowait
);
1363 trace_xfs_buf_iowait_done(bp
, _RET_IP_
);
1374 if (bp
->b_flags
& XBF_MAPPED
)
1375 return XFS_BUF_PTR(bp
) + offset
;
1377 offset
+= bp
->b_offset
;
1378 page
= bp
->b_pages
[offset
>> PAGE_CACHE_SHIFT
];
1379 return (xfs_caddr_t
)page_address(page
) + (offset
& (PAGE_CACHE_SIZE
-1));
1383 * Move data into or out of a buffer.
1387 xfs_buf_t
*bp
, /* buffer to process */
1388 size_t boff
, /* starting buffer offset */
1389 size_t bsize
, /* length to copy */
1390 void *data
, /* data address */
1391 xfs_buf_rw_t mode
) /* read/write/zero flag */
1393 size_t bend
, cpoff
, csize
;
1396 bend
= boff
+ bsize
;
1397 while (boff
< bend
) {
1398 page
= bp
->b_pages
[xfs_buf_btoct(boff
+ bp
->b_offset
)];
1399 cpoff
= xfs_buf_poff(boff
+ bp
->b_offset
);
1400 csize
= min_t(size_t,
1401 PAGE_CACHE_SIZE
-cpoff
, bp
->b_count_desired
-boff
);
1403 ASSERT(((csize
+ cpoff
) <= PAGE_CACHE_SIZE
));
1407 memset(page_address(page
) + cpoff
, 0, csize
);
1410 memcpy(data
, page_address(page
) + cpoff
, csize
);
1413 memcpy(page_address(page
) + cpoff
, data
, csize
);
1422 * Handling of buffer targets (buftargs).
1426 * Wait for any bufs with callbacks that have been submitted but
1427 * have not yet returned... walk the hash list for the target.
1434 xfs_bufhash_t
*hash
;
1437 for (i
= 0; i
< (1 << btp
->bt_hashshift
); i
++) {
1438 hash
= &btp
->bt_hash
[i
];
1440 spin_lock(&hash
->bh_lock
);
1441 list_for_each_entry_safe(bp
, n
, &hash
->bh_list
, b_hash_list
) {
1442 ASSERT(btp
== bp
->b_target
);
1443 if (!(bp
->b_flags
& XBF_FS_MANAGED
)) {
1444 spin_unlock(&hash
->bh_lock
);
1446 * Catch superblock reference count leaks
1449 BUG_ON(bp
->b_bn
== 0);
1454 spin_unlock(&hash
->bh_lock
);
1459 * Allocate buffer hash table for a given target.
1460 * For devices containing metadata (i.e. not the log/realtime devices)
1461 * we need to allocate a much larger hash table.
1470 btp
->bt_hashshift
= external
? 3 : 8; /* 8 or 256 buckets */
1471 btp
->bt_hashmask
= (1 << btp
->bt_hashshift
) - 1;
1472 btp
->bt_hash
= kmem_zalloc_large((1 << btp
->bt_hashshift
) *
1473 sizeof(xfs_bufhash_t
));
1474 for (i
= 0; i
< (1 << btp
->bt_hashshift
); i
++) {
1475 spin_lock_init(&btp
->bt_hash
[i
].bh_lock
);
1476 INIT_LIST_HEAD(&btp
->bt_hash
[i
].bh_list
);
1484 kmem_free_large(btp
->bt_hash
);
1485 btp
->bt_hash
= NULL
;
1489 * buftarg list for delwrite queue processing
1491 static LIST_HEAD(xfs_buftarg_list
);
1492 static DEFINE_SPINLOCK(xfs_buftarg_lock
);
1495 xfs_register_buftarg(
1498 spin_lock(&xfs_buftarg_lock
);
1499 list_add(&btp
->bt_list
, &xfs_buftarg_list
);
1500 spin_unlock(&xfs_buftarg_lock
);
1504 xfs_unregister_buftarg(
1507 spin_lock(&xfs_buftarg_lock
);
1508 list_del(&btp
->bt_list
);
1509 spin_unlock(&xfs_buftarg_lock
);
1514 struct xfs_mount
*mp
,
1515 struct xfs_buftarg
*btp
)
1517 xfs_flush_buftarg(btp
, 1);
1518 if (mp
->m_flags
& XFS_MOUNT_BARRIER
)
1519 xfs_blkdev_issue_flush(btp
);
1520 xfs_free_bufhash(btp
);
1521 iput(btp
->bt_mapping
->host
);
1523 /* Unregister the buftarg first so that we don't get a
1524 * wakeup finding a non-existent task
1526 xfs_unregister_buftarg(btp
);
1527 kthread_stop(btp
->bt_task
);
1533 xfs_setsize_buftarg_flags(
1535 unsigned int blocksize
,
1536 unsigned int sectorsize
,
1539 btp
->bt_bsize
= blocksize
;
1540 btp
->bt_sshift
= ffs(sectorsize
) - 1;
1541 btp
->bt_smask
= sectorsize
- 1;
1543 if (set_blocksize(btp
->bt_bdev
, sectorsize
)) {
1545 "XFS: Cannot set_blocksize to %u on device %s\n",
1546 sectorsize
, XFS_BUFTARG_NAME(btp
));
1551 (PAGE_CACHE_SIZE
/ BITS_PER_LONG
) > sectorsize
) {
1553 "XFS: %u byte sectors in use on device %s. "
1554 "This is suboptimal; %u or greater is ideal.\n",
1555 sectorsize
, XFS_BUFTARG_NAME(btp
),
1556 (unsigned int)PAGE_CACHE_SIZE
/ BITS_PER_LONG
);
1563 * When allocating the initial buffer target we have not yet
1564 * read in the superblock, so don't know what sized sectors
1565 * are being used is at this early stage. Play safe.
1568 xfs_setsize_buftarg_early(
1570 struct block_device
*bdev
)
1572 return xfs_setsize_buftarg_flags(btp
,
1573 PAGE_CACHE_SIZE
, bdev_logical_block_size(bdev
), 0);
1577 xfs_setsize_buftarg(
1579 unsigned int blocksize
,
1580 unsigned int sectorsize
)
1582 return xfs_setsize_buftarg_flags(btp
, blocksize
, sectorsize
, 1);
1586 xfs_mapping_buftarg(
1588 struct block_device
*bdev
)
1590 struct backing_dev_info
*bdi
;
1591 struct inode
*inode
;
1592 struct address_space
*mapping
;
1593 static const struct address_space_operations mapping_aops
= {
1594 .sync_page
= block_sync_page
,
1595 .migratepage
= fail_migrate_page
,
1598 inode
= new_inode(bdev
->bd_inode
->i_sb
);
1601 "XFS: Cannot allocate mapping inode for device %s\n",
1602 XFS_BUFTARG_NAME(btp
));
1605 inode
->i_mode
= S_IFBLK
;
1606 inode
->i_bdev
= bdev
;
1607 inode
->i_rdev
= bdev
->bd_dev
;
1608 bdi
= blk_get_backing_dev_info(bdev
);
1610 bdi
= &default_backing_dev_info
;
1611 mapping
= &inode
->i_data
;
1612 mapping
->a_ops
= &mapping_aops
;
1613 mapping
->backing_dev_info
= bdi
;
1614 mapping_set_gfp_mask(mapping
, GFP_NOFS
);
1615 btp
->bt_mapping
= mapping
;
1620 xfs_alloc_delwrite_queue(
1626 INIT_LIST_HEAD(&btp
->bt_list
);
1627 INIT_LIST_HEAD(&btp
->bt_delwrite_queue
);
1628 spin_lock_init(&btp
->bt_delwrite_lock
);
1630 btp
->bt_task
= kthread_run(xfsbufd
, btp
, "xfsbufd/%s", fsname
);
1631 if (IS_ERR(btp
->bt_task
)) {
1632 error
= PTR_ERR(btp
->bt_task
);
1635 xfs_register_buftarg(btp
);
1642 struct block_device
*bdev
,
1648 btp
= kmem_zalloc(sizeof(*btp
), KM_SLEEP
);
1650 btp
->bt_dev
= bdev
->bd_dev
;
1651 btp
->bt_bdev
= bdev
;
1652 if (xfs_setsize_buftarg_early(btp
, bdev
))
1654 if (xfs_mapping_buftarg(btp
, bdev
))
1656 if (xfs_alloc_delwrite_queue(btp
, fsname
))
1658 xfs_alloc_bufhash(btp
, external
);
1668 * Delayed write buffer handling
1671 xfs_buf_delwri_queue(
1675 struct list_head
*dwq
= &bp
->b_target
->bt_delwrite_queue
;
1676 spinlock_t
*dwlk
= &bp
->b_target
->bt_delwrite_lock
;
1678 trace_xfs_buf_delwri_queue(bp
, _RET_IP_
);
1680 ASSERT((bp
->b_flags
&(XBF_DELWRI
|XBF_ASYNC
)) == (XBF_DELWRI
|XBF_ASYNC
));
1683 /* If already in the queue, dequeue and place at tail */
1684 if (!list_empty(&bp
->b_list
)) {
1685 ASSERT(bp
->b_flags
& _XBF_DELWRI_Q
);
1687 atomic_dec(&bp
->b_hold
);
1688 list_del(&bp
->b_list
);
1691 if (list_empty(dwq
)) {
1692 /* start xfsbufd as it is about to have something to do */
1693 wake_up_process(bp
->b_target
->bt_task
);
1696 bp
->b_flags
|= _XBF_DELWRI_Q
;
1697 list_add_tail(&bp
->b_list
, dwq
);
1698 bp
->b_queuetime
= jiffies
;
1706 xfs_buf_delwri_dequeue(
1709 spinlock_t
*dwlk
= &bp
->b_target
->bt_delwrite_lock
;
1713 if ((bp
->b_flags
& XBF_DELWRI
) && !list_empty(&bp
->b_list
)) {
1714 ASSERT(bp
->b_flags
& _XBF_DELWRI_Q
);
1715 list_del_init(&bp
->b_list
);
1718 bp
->b_flags
&= ~(XBF_DELWRI
|_XBF_DELWRI_Q
);
1724 trace_xfs_buf_delwri_dequeue(bp
, _RET_IP_
);
1728 * If a delwri buffer needs to be pushed before it has aged out, then promote
1729 * it to the head of the delwri queue so that it will be flushed on the next
1730 * xfsbufd run. We do this by resetting the queuetime of the buffer to be older
1731 * than the age currently needed to flush the buffer. Hence the next time the
1732 * xfsbufd sees it is guaranteed to be considered old enough to flush.
1735 xfs_buf_delwri_promote(
1738 struct xfs_buftarg
*btp
= bp
->b_target
;
1739 long age
= xfs_buf_age_centisecs
* msecs_to_jiffies(10) + 1;
1741 ASSERT(bp
->b_flags
& XBF_DELWRI
);
1742 ASSERT(bp
->b_flags
& _XBF_DELWRI_Q
);
1745 * Check the buffer age before locking the delayed write queue as we
1746 * don't need to promote buffers that are already past the flush age.
1748 if (bp
->b_queuetime
< jiffies
- age
)
1750 bp
->b_queuetime
= jiffies
- age
;
1751 spin_lock(&btp
->bt_delwrite_lock
);
1752 list_move(&bp
->b_list
, &btp
->bt_delwrite_queue
);
1753 spin_unlock(&btp
->bt_delwrite_lock
);
1757 xfs_buf_runall_queues(
1758 struct workqueue_struct
*queue
)
1760 flush_workqueue(queue
);
1765 struct shrinker
*shrink
,
1771 spin_lock(&xfs_buftarg_lock
);
1772 list_for_each_entry(btp
, &xfs_buftarg_list
, bt_list
) {
1773 if (test_bit(XBT_FORCE_SLEEP
, &btp
->bt_flags
))
1775 if (list_empty(&btp
->bt_delwrite_queue
))
1777 set_bit(XBT_FORCE_FLUSH
, &btp
->bt_flags
);
1778 wake_up_process(btp
->bt_task
);
1780 spin_unlock(&xfs_buftarg_lock
);
1785 * Move as many buffers as specified to the supplied list
1786 * idicating if we skipped any buffers to prevent deadlocks.
1789 xfs_buf_delwri_split(
1790 xfs_buftarg_t
*target
,
1791 struct list_head
*list
,
1795 struct list_head
*dwq
= &target
->bt_delwrite_queue
;
1796 spinlock_t
*dwlk
= &target
->bt_delwrite_lock
;
1800 force
= test_and_clear_bit(XBT_FORCE_FLUSH
, &target
->bt_flags
);
1801 INIT_LIST_HEAD(list
);
1803 list_for_each_entry_safe(bp
, n
, dwq
, b_list
) {
1804 trace_xfs_buf_delwri_split(bp
, _RET_IP_
);
1805 ASSERT(bp
->b_flags
& XBF_DELWRI
);
1807 if (!xfs_buf_ispin(bp
) && !xfs_buf_cond_lock(bp
)) {
1809 time_before(jiffies
, bp
->b_queuetime
+ age
)) {
1814 bp
->b_flags
&= ~(XBF_DELWRI
|_XBF_DELWRI_Q
|
1816 bp
->b_flags
|= XBF_WRITE
;
1817 list_move_tail(&bp
->b_list
, list
);
1828 * Compare function is more complex than it needs to be because
1829 * the return value is only 32 bits and we are doing comparisons
1835 struct list_head
*a
,
1836 struct list_head
*b
)
1838 struct xfs_buf
*ap
= container_of(a
, struct xfs_buf
, b_list
);
1839 struct xfs_buf
*bp
= container_of(b
, struct xfs_buf
, b_list
);
1842 diff
= ap
->b_bn
- bp
->b_bn
;
1851 xfs_buf_delwri_sort(
1852 xfs_buftarg_t
*target
,
1853 struct list_head
*list
)
1855 list_sort(NULL
, list
, xfs_buf_cmp
);
1862 xfs_buftarg_t
*target
= (xfs_buftarg_t
*)data
;
1864 current
->flags
|= PF_MEMALLOC
;
1869 long age
= xfs_buf_age_centisecs
* msecs_to_jiffies(10);
1870 long tout
= xfs_buf_timer_centisecs
* msecs_to_jiffies(10);
1872 struct list_head tmp
;
1874 if (unlikely(freezing(current
))) {
1875 set_bit(XBT_FORCE_SLEEP
, &target
->bt_flags
);
1878 clear_bit(XBT_FORCE_SLEEP
, &target
->bt_flags
);
1881 /* sleep for a long time if there is nothing to do. */
1882 if (list_empty(&target
->bt_delwrite_queue
))
1883 tout
= MAX_SCHEDULE_TIMEOUT
;
1884 schedule_timeout_interruptible(tout
);
1886 xfs_buf_delwri_split(target
, &tmp
, age
);
1887 list_sort(NULL
, &tmp
, xfs_buf_cmp
);
1888 while (!list_empty(&tmp
)) {
1890 bp
= list_first_entry(&tmp
, struct xfs_buf
, b_list
);
1891 list_del_init(&bp
->b_list
);
1892 xfs_buf_iostrategy(bp
);
1896 blk_run_address_space(target
->bt_mapping
);
1898 } while (!kthread_should_stop());
1904 * Go through all incore buffers, and release buffers if they belong to
1905 * the given device. This is used in filesystem error handling to
1906 * preserve the consistency of its metadata.
1910 xfs_buftarg_t
*target
,
1915 LIST_HEAD(tmp_list
);
1916 LIST_HEAD(wait_list
);
1918 xfs_buf_runall_queues(xfsconvertd_workqueue
);
1919 xfs_buf_runall_queues(xfsdatad_workqueue
);
1920 xfs_buf_runall_queues(xfslogd_workqueue
);
1922 set_bit(XBT_FORCE_FLUSH
, &target
->bt_flags
);
1923 pincount
= xfs_buf_delwri_split(target
, &tmp_list
, 0);
1926 * Dropped the delayed write list lock, now walk the temporary list.
1927 * All I/O is issued async and then if we need to wait for completion
1928 * we do that after issuing all the IO.
1930 list_sort(NULL
, &tmp_list
, xfs_buf_cmp
);
1931 while (!list_empty(&tmp_list
)) {
1932 bp
= list_first_entry(&tmp_list
, struct xfs_buf
, b_list
);
1933 ASSERT(target
== bp
->b_target
);
1934 list_del_init(&bp
->b_list
);
1936 bp
->b_flags
&= ~XBF_ASYNC
;
1937 list_add(&bp
->b_list
, &wait_list
);
1939 xfs_buf_iostrategy(bp
);
1943 /* Expedite and wait for IO to complete. */
1944 blk_run_address_space(target
->bt_mapping
);
1945 while (!list_empty(&wait_list
)) {
1946 bp
= list_first_entry(&wait_list
, struct xfs_buf
, b_list
);
1948 list_del_init(&bp
->b_list
);
1960 xfs_buf_zone
= kmem_zone_init_flags(sizeof(xfs_buf_t
), "xfs_buf",
1961 KM_ZONE_HWALIGN
, NULL
);
1965 xfslogd_workqueue
= create_workqueue("xfslogd");
1966 if (!xfslogd_workqueue
)
1967 goto out_free_buf_zone
;
1969 xfsdatad_workqueue
= create_workqueue("xfsdatad");
1970 if (!xfsdatad_workqueue
)
1971 goto out_destroy_xfslogd_workqueue
;
1973 xfsconvertd_workqueue
= create_workqueue("xfsconvertd");
1974 if (!xfsconvertd_workqueue
)
1975 goto out_destroy_xfsdatad_workqueue
;
1977 register_shrinker(&xfs_buf_shake
);
1980 out_destroy_xfsdatad_workqueue
:
1981 destroy_workqueue(xfsdatad_workqueue
);
1982 out_destroy_xfslogd_workqueue
:
1983 destroy_workqueue(xfslogd_workqueue
);
1985 kmem_zone_destroy(xfs_buf_zone
);
1991 xfs_buf_terminate(void)
1993 unregister_shrinker(&xfs_buf_shake
);
1994 destroy_workqueue(xfsconvertd_workqueue
);
1995 destroy_workqueue(xfsdatad_workqueue
);
1996 destroy_workqueue(xfslogd_workqueue
);
1997 kmem_zone_destroy(xfs_buf_zone
);
2000 #ifdef CONFIG_KDB_MODULES
2002 xfs_get_buftarg_list(void)
2004 return &xfs_buftarg_list
;