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>
41 #include "xfs_mount.h"
42 #include "xfs_trace.h"
44 static kmem_zone_t
*xfs_buf_zone
;
45 STATIC
int xfsbufd(void *);
46 STATIC
void xfs_buf_delwri_queue(xfs_buf_t
*);
48 static struct workqueue_struct
*xfslogd_workqueue
;
49 struct workqueue_struct
*xfsdatad_workqueue
;
50 struct workqueue_struct
*xfsconvertd_workqueue
;
52 #ifdef XFS_BUF_LOCK_TRACKING
53 # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid)
54 # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1)
55 # define XB_GET_OWNER(bp) ((bp)->b_last_holder)
57 # define XB_SET_OWNER(bp) do { } while (0)
58 # define XB_CLEAR_OWNER(bp) do { } while (0)
59 # define XB_GET_OWNER(bp) do { } while (0)
62 #define xb_to_gfp(flags) \
63 ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \
64 ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN)
66 #define xb_to_km(flags) \
67 (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP)
69 #define xfs_buf_allocate(flags) \
70 kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags))
71 #define xfs_buf_deallocate(bp) \
72 kmem_zone_free(xfs_buf_zone, (bp));
79 * Return true if the buffer is vmapped.
81 * The XBF_MAPPED flag is set if the buffer should be mapped, but the
82 * code is clever enough to know it doesn't have to map a single page,
83 * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1.
85 return (bp
->b_flags
& XBF_MAPPED
) && bp
->b_page_count
> 1;
92 return (bp
->b_page_count
* PAGE_SIZE
) - bp
->b_offset
;
96 * xfs_buf_lru_add - add a buffer to the LRU.
98 * The LRU takes a new reference to the buffer so that it will only be freed
99 * once the shrinker takes the buffer off the LRU.
105 struct xfs_buftarg
*btp
= bp
->b_target
;
107 spin_lock(&btp
->bt_lru_lock
);
108 if (list_empty(&bp
->b_lru
)) {
109 atomic_inc(&bp
->b_hold
);
110 list_add_tail(&bp
->b_lru
, &btp
->bt_lru
);
113 spin_unlock(&btp
->bt_lru_lock
);
117 * xfs_buf_lru_del - remove a buffer from the LRU
119 * The unlocked check is safe here because it only occurs when there are not
120 * b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there
121 * to optimise the shrinker removing the buffer from the LRU and calling
122 * xfs_buf_free(). i.e. it removes an unnecessary round trip on the
129 struct xfs_buftarg
*btp
= bp
->b_target
;
131 if (list_empty(&bp
->b_lru
))
134 spin_lock(&btp
->bt_lru_lock
);
135 if (!list_empty(&bp
->b_lru
)) {
136 list_del_init(&bp
->b_lru
);
139 spin_unlock(&btp
->bt_lru_lock
);
143 * When we mark a buffer stale, we remove the buffer from the LRU and clear the
144 * b_lru_ref count so that the buffer is freed immediately when the buffer
145 * reference count falls to zero. If the buffer is already on the LRU, we need
146 * to remove the reference that LRU holds on the buffer.
148 * This prevents build-up of stale buffers on the LRU.
154 bp
->b_flags
|= XBF_STALE
;
155 atomic_set(&(bp
)->b_lru_ref
, 0);
156 if (!list_empty(&bp
->b_lru
)) {
157 struct xfs_buftarg
*btp
= bp
->b_target
;
159 spin_lock(&btp
->bt_lru_lock
);
160 if (!list_empty(&bp
->b_lru
)) {
161 list_del_init(&bp
->b_lru
);
163 atomic_dec(&bp
->b_hold
);
165 spin_unlock(&btp
->bt_lru_lock
);
167 ASSERT(atomic_read(&bp
->b_hold
) >= 1);
173 xfs_buftarg_t
*target
,
174 xfs_off_t range_base
,
176 xfs_buf_flags_t flags
)
179 * We don't want certain flags to appear in b_flags.
181 flags
&= ~(XBF_LOCK
|XBF_MAPPED
|XBF_DONT_BLOCK
|XBF_READ_AHEAD
);
183 memset(bp
, 0, sizeof(xfs_buf_t
));
184 atomic_set(&bp
->b_hold
, 1);
185 atomic_set(&bp
->b_lru_ref
, 1);
186 init_completion(&bp
->b_iowait
);
187 INIT_LIST_HEAD(&bp
->b_lru
);
188 INIT_LIST_HEAD(&bp
->b_list
);
189 RB_CLEAR_NODE(&bp
->b_rbnode
);
190 sema_init(&bp
->b_sema
, 0); /* held, no waiters */
192 bp
->b_target
= target
;
193 bp
->b_file_offset
= range_base
;
195 * Set buffer_length and count_desired to the same value initially.
196 * I/O routines should use count_desired, which will be the same in
197 * most cases but may be reset (e.g. XFS recovery).
199 bp
->b_buffer_length
= bp
->b_count_desired
= range_length
;
201 bp
->b_bn
= XFS_BUF_DADDR_NULL
;
202 atomic_set(&bp
->b_pin_count
, 0);
203 init_waitqueue_head(&bp
->b_waiters
);
205 XFS_STATS_INC(xb_create
);
207 trace_xfs_buf_init(bp
, _RET_IP_
);
211 * Allocate a page array capable of holding a specified number
212 * of pages, and point the page buf at it.
218 xfs_buf_flags_t flags
)
220 /* Make sure that we have a page list */
221 if (bp
->b_pages
== NULL
) {
222 bp
->b_offset
= xfs_buf_poff(bp
->b_file_offset
);
223 bp
->b_page_count
= page_count
;
224 if (page_count
<= XB_PAGES
) {
225 bp
->b_pages
= bp
->b_page_array
;
227 bp
->b_pages
= kmem_alloc(sizeof(struct page
*) *
228 page_count
, xb_to_km(flags
));
229 if (bp
->b_pages
== NULL
)
232 memset(bp
->b_pages
, 0, sizeof(struct page
*) * page_count
);
238 * Frees b_pages if it was allocated.
244 if (bp
->b_pages
!= bp
->b_page_array
) {
245 kmem_free(bp
->b_pages
);
251 * Releases the specified buffer.
253 * The modification state of any associated pages is left unchanged.
254 * The buffer most not be on any hash - use xfs_buf_rele instead for
255 * hashed and refcounted buffers
261 trace_xfs_buf_free(bp
, _RET_IP_
);
263 ASSERT(list_empty(&bp
->b_lru
));
265 if (bp
->b_flags
& _XBF_PAGES
) {
268 if (xfs_buf_is_vmapped(bp
))
269 vm_unmap_ram(bp
->b_addr
- bp
->b_offset
,
272 for (i
= 0; i
< bp
->b_page_count
; i
++) {
273 struct page
*page
= bp
->b_pages
[i
];
277 } else if (bp
->b_flags
& _XBF_KMEM
)
278 kmem_free(bp
->b_addr
);
279 _xfs_buf_free_pages(bp
);
280 xfs_buf_deallocate(bp
);
284 * Allocates all the pages for buffer in question and builds it's page list.
287 xfs_buf_allocate_memory(
291 size_t size
= bp
->b_count_desired
;
292 size_t nbytes
, offset
;
293 gfp_t gfp_mask
= xb_to_gfp(flags
);
294 unsigned short page_count
, i
;
299 * for buffers that are contained within a single page, just allocate
300 * the memory from the heap - there's no need for the complexity of
301 * page arrays to keep allocation down to order 0.
303 if (bp
->b_buffer_length
< PAGE_SIZE
) {
304 bp
->b_addr
= kmem_alloc(bp
->b_buffer_length
, xb_to_km(flags
));
306 /* low memory - use alloc_page loop instead */
310 if (((unsigned long)(bp
->b_addr
+ bp
->b_buffer_length
- 1) &
312 ((unsigned long)bp
->b_addr
& PAGE_MASK
)) {
313 /* b_addr spans two pages - use alloc_page instead */
314 kmem_free(bp
->b_addr
);
318 bp
->b_offset
= offset_in_page(bp
->b_addr
);
319 bp
->b_pages
= bp
->b_page_array
;
320 bp
->b_pages
[0] = virt_to_page(bp
->b_addr
);
321 bp
->b_page_count
= 1;
322 bp
->b_flags
|= XBF_MAPPED
| _XBF_KMEM
;
327 end
= bp
->b_file_offset
+ bp
->b_buffer_length
;
328 page_count
= xfs_buf_btoc(end
) - xfs_buf_btoct(bp
->b_file_offset
);
329 error
= _xfs_buf_get_pages(bp
, page_count
, flags
);
333 offset
= bp
->b_offset
;
334 bp
->b_flags
|= _XBF_PAGES
;
336 for (i
= 0; i
< bp
->b_page_count
; i
++) {
340 page
= alloc_page(gfp_mask
);
341 if (unlikely(page
== NULL
)) {
342 if (flags
& XBF_READ_AHEAD
) {
343 bp
->b_page_count
= i
;
349 * This could deadlock.
351 * But until all the XFS lowlevel code is revamped to
352 * handle buffer allocation failures we can't do much.
354 if (!(++retries
% 100))
356 "possible memory allocation deadlock in %s (mode:0x%x)",
359 XFS_STATS_INC(xb_page_retries
);
360 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
364 XFS_STATS_INC(xb_page_found
);
366 nbytes
= min_t(size_t, size
, PAGE_SIZE
- offset
);
368 bp
->b_pages
[i
] = page
;
374 for (i
= 0; i
< bp
->b_page_count
; i
++)
375 __free_page(bp
->b_pages
[i
]);
380 * Map buffer into kernel address-space if necessary.
387 ASSERT(bp
->b_flags
& _XBF_PAGES
);
388 if (bp
->b_page_count
== 1) {
389 /* A single page buffer is always mappable */
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
) {
396 bp
->b_addr
= vm_map_ram(bp
->b_pages
, bp
->b_page_count
,
401 } while (retried
++ <= 1);
405 bp
->b_addr
+= bp
->b_offset
;
406 bp
->b_flags
|= XBF_MAPPED
;
413 * Finding and Reading Buffers
417 * Look up, and creates if absent, a lockable buffer for
418 * a given range of an inode. The buffer is returned
419 * locked. If other overlapping buffers exist, they are
420 * released before the new buffer is created and locked,
421 * which may imply that this call will block until those buffers
422 * are unlocked. No I/O is implied by this call.
426 xfs_buftarg_t
*btp
, /* block device target */
427 xfs_off_t ioff
, /* starting offset of range */
428 size_t isize
, /* length of range */
429 xfs_buf_flags_t flags
,
432 xfs_off_t range_base
;
434 struct xfs_perag
*pag
;
435 struct rb_node
**rbp
;
436 struct rb_node
*parent
;
439 range_base
= (ioff
<< BBSHIFT
);
440 range_length
= (isize
<< BBSHIFT
);
442 /* Check for IOs smaller than the sector size / not sector aligned */
443 ASSERT(!(range_length
< (1 << btp
->bt_sshift
)));
444 ASSERT(!(range_base
& (xfs_off_t
)btp
->bt_smask
));
447 pag
= xfs_perag_get(btp
->bt_mount
,
448 xfs_daddr_to_agno(btp
->bt_mount
, ioff
));
451 spin_lock(&pag
->pag_buf_lock
);
452 rbp
= &pag
->pag_buf_tree
.rb_node
;
457 bp
= rb_entry(parent
, struct xfs_buf
, b_rbnode
);
459 if (range_base
< bp
->b_file_offset
)
460 rbp
= &(*rbp
)->rb_left
;
461 else if (range_base
> bp
->b_file_offset
)
462 rbp
= &(*rbp
)->rb_right
;
465 * found a block offset match. If the range doesn't
466 * match, the only way this is allowed is if the buffer
467 * in the cache is stale and the transaction that made
468 * it stale has not yet committed. i.e. we are
469 * reallocating a busy extent. Skip this buffer and
470 * continue searching to the right for an exact match.
472 if (bp
->b_buffer_length
!= range_length
) {
473 ASSERT(bp
->b_flags
& XBF_STALE
);
474 rbp
= &(*rbp
)->rb_right
;
477 atomic_inc(&bp
->b_hold
);
484 _xfs_buf_initialize(new_bp
, btp
, range_base
,
485 range_length
, flags
);
486 rb_link_node(&new_bp
->b_rbnode
, parent
, rbp
);
487 rb_insert_color(&new_bp
->b_rbnode
, &pag
->pag_buf_tree
);
488 /* the buffer keeps the perag reference until it is freed */
490 spin_unlock(&pag
->pag_buf_lock
);
492 XFS_STATS_INC(xb_miss_locked
);
493 spin_unlock(&pag
->pag_buf_lock
);
499 spin_unlock(&pag
->pag_buf_lock
);
502 if (!xfs_buf_trylock(bp
)) {
503 if (flags
& XBF_TRYLOCK
) {
505 XFS_STATS_INC(xb_busy_locked
);
509 XFS_STATS_INC(xb_get_locked_waited
);
513 * if the buffer is stale, clear all the external state associated with
514 * it. We need to keep flags such as how we allocated the buffer memory
517 if (bp
->b_flags
& XBF_STALE
) {
518 ASSERT((bp
->b_flags
& _XBF_DELWRI_Q
) == 0);
519 bp
->b_flags
&= XBF_MAPPED
| _XBF_KMEM
| _XBF_PAGES
;
522 trace_xfs_buf_find(bp
, flags
, _RET_IP_
);
523 XFS_STATS_INC(xb_get_locked
);
528 * Assembles a buffer covering the specified range.
529 * Storage in memory for all portions of the buffer will be allocated,
530 * although backing storage may not be.
534 xfs_buftarg_t
*target
,/* target for buffer */
535 xfs_off_t ioff
, /* starting offset of range */
536 size_t isize
, /* length of range */
537 xfs_buf_flags_t flags
)
539 xfs_buf_t
*bp
, *new_bp
;
542 new_bp
= xfs_buf_allocate(flags
);
543 if (unlikely(!new_bp
))
546 bp
= _xfs_buf_find(target
, ioff
, isize
, flags
, new_bp
);
548 error
= xfs_buf_allocate_memory(bp
, flags
);
552 xfs_buf_deallocate(new_bp
);
553 if (unlikely(bp
== NULL
))
557 if (!(bp
->b_flags
& XBF_MAPPED
)) {
558 error
= _xfs_buf_map_pages(bp
, flags
);
559 if (unlikely(error
)) {
560 xfs_warn(target
->bt_mount
,
561 "%s: failed to map pages\n", __func__
);
566 XFS_STATS_INC(xb_get
);
569 * Always fill in the block number now, the mapped cases can do
570 * their own overlay of this later.
573 bp
->b_count_desired
= bp
->b_buffer_length
;
575 trace_xfs_buf_get(bp
, flags
, _RET_IP_
);
579 if (flags
& (XBF_LOCK
| XBF_TRYLOCK
))
588 xfs_buf_flags_t flags
)
592 ASSERT(!(flags
& (XBF_DELWRI
|XBF_WRITE
)));
593 ASSERT(bp
->b_bn
!= XFS_BUF_DADDR_NULL
);
595 bp
->b_flags
&= ~(XBF_WRITE
| XBF_ASYNC
| XBF_DELWRI
| XBF_READ_AHEAD
);
596 bp
->b_flags
|= flags
& (XBF_READ
| XBF_ASYNC
| XBF_READ_AHEAD
);
598 status
= xfs_buf_iorequest(bp
);
599 if (status
|| bp
->b_error
|| (flags
& XBF_ASYNC
))
601 return xfs_buf_iowait(bp
);
606 xfs_buftarg_t
*target
,
609 xfs_buf_flags_t flags
)
615 bp
= xfs_buf_get(target
, ioff
, isize
, flags
);
617 trace_xfs_buf_read(bp
, flags
, _RET_IP_
);
619 if (!XFS_BUF_ISDONE(bp
)) {
620 XFS_STATS_INC(xb_get_read
);
621 _xfs_buf_read(bp
, flags
);
622 } else if (flags
& XBF_ASYNC
) {
624 * Read ahead call which is already satisfied,
629 /* We do not want read in the flags */
630 bp
->b_flags
&= ~XBF_READ
;
637 if (flags
& (XBF_LOCK
| XBF_TRYLOCK
))
644 * If we are not low on memory then do the readahead in a deadlock
649 xfs_buftarg_t
*target
,
653 if (bdi_read_congested(target
->bt_bdi
))
656 xfs_buf_read(target
, ioff
, isize
,
657 XBF_TRYLOCK
|XBF_ASYNC
|XBF_READ_AHEAD
|XBF_DONT_BLOCK
);
661 * Read an uncached buffer from disk. Allocates and returns a locked
662 * buffer containing the disk contents or nothing.
665 xfs_buf_read_uncached(
666 struct xfs_mount
*mp
,
667 struct xfs_buftarg
*target
,
675 bp
= xfs_buf_get_uncached(target
, length
, flags
);
679 /* set up the buffer for a read IO */
680 XFS_BUF_SET_ADDR(bp
, daddr
);
684 error
= xfs_buf_iowait(bp
);
685 if (error
|| bp
->b_error
) {
695 xfs_buftarg_t
*target
)
699 bp
= xfs_buf_allocate(0);
701 _xfs_buf_initialize(bp
, target
, 0, len
, 0);
706 * Return a buffer allocated as an empty buffer and associated to external
707 * memory via xfs_buf_associate_memory() back to it's empty state.
715 _xfs_buf_free_pages(bp
);
718 bp
->b_page_count
= 0;
720 bp
->b_file_offset
= 0;
721 bp
->b_buffer_length
= bp
->b_count_desired
= len
;
722 bp
->b_bn
= XFS_BUF_DADDR_NULL
;
723 bp
->b_flags
&= ~XBF_MAPPED
;
726 static inline struct page
*
730 if ((!is_vmalloc_addr(addr
))) {
731 return virt_to_page(addr
);
733 return vmalloc_to_page(addr
);
738 xfs_buf_associate_memory(
745 unsigned long pageaddr
;
746 unsigned long offset
;
750 pageaddr
= (unsigned long)mem
& PAGE_MASK
;
751 offset
= (unsigned long)mem
- pageaddr
;
752 buflen
= PAGE_ALIGN(len
+ offset
);
753 page_count
= buflen
>> PAGE_SHIFT
;
755 /* Free any previous set of page pointers */
757 _xfs_buf_free_pages(bp
);
762 rval
= _xfs_buf_get_pages(bp
, page_count
, XBF_DONT_BLOCK
);
766 bp
->b_offset
= offset
;
768 for (i
= 0; i
< bp
->b_page_count
; i
++) {
769 bp
->b_pages
[i
] = mem_to_page((void *)pageaddr
);
770 pageaddr
+= PAGE_SIZE
;
773 bp
->b_count_desired
= len
;
774 bp
->b_buffer_length
= buflen
;
775 bp
->b_flags
|= XBF_MAPPED
;
781 xfs_buf_get_uncached(
782 struct xfs_buftarg
*target
,
786 unsigned long page_count
= PAGE_ALIGN(len
) >> PAGE_SHIFT
;
790 bp
= xfs_buf_allocate(0);
791 if (unlikely(bp
== NULL
))
793 _xfs_buf_initialize(bp
, target
, 0, len
, 0);
795 error
= _xfs_buf_get_pages(bp
, page_count
, 0);
799 for (i
= 0; i
< page_count
; i
++) {
800 bp
->b_pages
[i
] = alloc_page(xb_to_gfp(flags
));
804 bp
->b_flags
|= _XBF_PAGES
;
806 error
= _xfs_buf_map_pages(bp
, XBF_MAPPED
);
807 if (unlikely(error
)) {
808 xfs_warn(target
->bt_mount
,
809 "%s: failed to map pages\n", __func__
);
813 trace_xfs_buf_get_uncached(bp
, _RET_IP_
);
818 __free_page(bp
->b_pages
[i
]);
819 _xfs_buf_free_pages(bp
);
821 xfs_buf_deallocate(bp
);
827 * Increment reference count on buffer, to hold the buffer concurrently
828 * with another thread which may release (free) the buffer asynchronously.
829 * Must hold the buffer already to call this function.
835 trace_xfs_buf_hold(bp
, _RET_IP_
);
836 atomic_inc(&bp
->b_hold
);
840 * Releases a hold on the specified buffer. If the
841 * the hold count is 1, calls xfs_buf_free.
847 struct xfs_perag
*pag
= bp
->b_pag
;
849 trace_xfs_buf_rele(bp
, _RET_IP_
);
852 ASSERT(list_empty(&bp
->b_lru
));
853 ASSERT(RB_EMPTY_NODE(&bp
->b_rbnode
));
854 if (atomic_dec_and_test(&bp
->b_hold
))
859 ASSERT(!RB_EMPTY_NODE(&bp
->b_rbnode
));
861 ASSERT(atomic_read(&bp
->b_hold
) > 0);
862 if (atomic_dec_and_lock(&bp
->b_hold
, &pag
->pag_buf_lock
)) {
863 if (!(bp
->b_flags
& XBF_STALE
) &&
864 atomic_read(&bp
->b_lru_ref
)) {
866 spin_unlock(&pag
->pag_buf_lock
);
869 ASSERT(!(bp
->b_flags
& (XBF_DELWRI
|_XBF_DELWRI_Q
)));
870 rb_erase(&bp
->b_rbnode
, &pag
->pag_buf_tree
);
871 spin_unlock(&pag
->pag_buf_lock
);
880 * Lock a buffer object, if it is not already locked.
882 * If we come across a stale, pinned, locked buffer, we know that we are
883 * being asked to lock a buffer that has been reallocated. Because it is
884 * pinned, we know that the log has not been pushed to disk and hence it
885 * will still be locked. Rather than continuing to have trylock attempts
886 * fail until someone else pushes the log, push it ourselves before
887 * returning. This means that the xfsaild will not get stuck trying
888 * to push on stale inode buffers.
896 locked
= down_trylock(&bp
->b_sema
) == 0;
899 else if (atomic_read(&bp
->b_pin_count
) && (bp
->b_flags
& XBF_STALE
))
900 xfs_log_force(bp
->b_target
->bt_mount
, 0);
902 trace_xfs_buf_trylock(bp
, _RET_IP_
);
907 * Lock a buffer object.
909 * If we come across a stale, pinned, locked buffer, we know that we
910 * are being asked to lock a buffer that has been reallocated. Because
911 * it is pinned, we know that the log has not been pushed to disk and
912 * hence it will still be locked. Rather than sleeping until someone
913 * else pushes the log, push it ourselves before trying to get the lock.
919 trace_xfs_buf_lock(bp
, _RET_IP_
);
921 if (atomic_read(&bp
->b_pin_count
) && (bp
->b_flags
& XBF_STALE
))
922 xfs_log_force(bp
->b_target
->bt_mount
, 0);
926 trace_xfs_buf_lock_done(bp
, _RET_IP_
);
930 * Releases the lock on the buffer object.
931 * If the buffer is marked delwri but is not queued, do so before we
932 * unlock the buffer as we need to set flags correctly. We also need to
933 * take a reference for the delwri queue because the unlocker is going to
934 * drop their's and they don't know we just queued it.
940 if ((bp
->b_flags
& (XBF_DELWRI
|_XBF_DELWRI_Q
)) == XBF_DELWRI
)
941 xfs_buf_delwri_queue(bp
);
946 trace_xfs_buf_unlock(bp
, _RET_IP_
);
953 DECLARE_WAITQUEUE (wait
, current
);
955 if (atomic_read(&bp
->b_pin_count
) == 0)
958 add_wait_queue(&bp
->b_waiters
, &wait
);
960 set_current_state(TASK_UNINTERRUPTIBLE
);
961 if (atomic_read(&bp
->b_pin_count
) == 0)
965 remove_wait_queue(&bp
->b_waiters
, &wait
);
966 set_current_state(TASK_RUNNING
);
970 * Buffer Utility Routines
975 struct work_struct
*work
)
978 container_of(work
, xfs_buf_t
, b_iodone_work
);
981 (*(bp
->b_iodone
))(bp
);
982 else if (bp
->b_flags
& XBF_ASYNC
)
991 trace_xfs_buf_iodone(bp
, _RET_IP_
);
993 bp
->b_flags
&= ~(XBF_READ
| XBF_WRITE
| XBF_READ_AHEAD
);
994 if (bp
->b_error
== 0)
995 bp
->b_flags
|= XBF_DONE
;
997 if ((bp
->b_iodone
) || (bp
->b_flags
& XBF_ASYNC
)) {
999 INIT_WORK(&bp
->b_iodone_work
, xfs_buf_iodone_work
);
1000 queue_work(xfslogd_workqueue
, &bp
->b_iodone_work
);
1002 xfs_buf_iodone_work(&bp
->b_iodone_work
);
1005 complete(&bp
->b_iowait
);
1014 ASSERT(error
>= 0 && error
<= 0xffff);
1015 bp
->b_error
= (unsigned short)error
;
1016 trace_xfs_buf_ioerror(bp
, error
, _RET_IP_
);
1021 struct xfs_mount
*mp
,
1026 bp
->b_flags
|= XBF_WRITE
;
1027 bp
->b_flags
&= ~(XBF_ASYNC
| XBF_READ
);
1029 xfs_buf_delwri_dequeue(bp
);
1032 error
= xfs_buf_iowait(bp
);
1034 xfs_force_shutdown(mp
, SHUTDOWN_META_IO_ERROR
);
1044 trace_xfs_buf_bdwrite(bp
, _RET_IP_
);
1046 xfs_buf_delwri_queue(bp
);
1051 * Called when we want to stop a buffer from getting written or read.
1052 * We attach the EIO error, muck with its flags, and call xfs_buf_ioend
1053 * so that the proper iodone callbacks get called.
1059 #ifdef XFSERRORDEBUG
1060 ASSERT(XFS_BUF_ISREAD(bp
) || bp
->b_iodone
);
1064 * No need to wait until the buffer is unpinned, we aren't flushing it.
1066 xfs_buf_ioerror(bp
, EIO
);
1069 * We're calling xfs_buf_ioend, so delete XBF_DONE flag.
1072 XFS_BUF_UNDELAYWRITE(bp
);
1076 xfs_buf_ioend(bp
, 0);
1082 * Same as xfs_bioerror, except that we are releasing the buffer
1083 * here ourselves, and avoiding the xfs_buf_ioend call.
1084 * This is meant for userdata errors; metadata bufs come with
1085 * iodone functions attached, so that we can track down errors.
1091 int64_t fl
= bp
->b_flags
;
1093 * No need to wait until the buffer is unpinned.
1094 * We aren't flushing it.
1096 * chunkhold expects B_DONE to be set, whether
1097 * we actually finish the I/O or not. We don't want to
1098 * change that interface.
1101 XFS_BUF_UNDELAYWRITE(bp
);
1104 bp
->b_iodone
= NULL
;
1105 if (!(fl
& XBF_ASYNC
)) {
1107 * Mark b_error and B_ERROR _both_.
1108 * Lot's of chunkcache code assumes that.
1109 * There's no reason to mark error for
1112 xfs_buf_ioerror(bp
, EIO
);
1113 XFS_BUF_FINISH_IOWAIT(bp
);
1123 * All xfs metadata buffers except log state machine buffers
1124 * get this attached as their b_bdstrat callback function.
1125 * This is so that we can catch a buffer
1126 * after prematurely unpinning it to forcibly shutdown the filesystem.
1132 if (XFS_FORCED_SHUTDOWN(bp
->b_target
->bt_mount
)) {
1133 trace_xfs_bdstrat_shut(bp
, _RET_IP_
);
1135 * Metadata write that didn't get logged but
1136 * written delayed anyway. These aren't associated
1137 * with a transaction, and can be ignored.
1139 if (!bp
->b_iodone
&& !XFS_BUF_ISREAD(bp
))
1140 return xfs_bioerror_relse(bp
);
1142 return xfs_bioerror(bp
);
1145 xfs_buf_iorequest(bp
);
1150 * Wrapper around bdstrat so that we can stop data from going to disk in case
1151 * we are shutting down the filesystem. Typically user data goes thru this
1152 * path; one of the exceptions is the superblock.
1156 struct xfs_mount
*mp
,
1159 if (XFS_FORCED_SHUTDOWN(mp
)) {
1160 trace_xfs_bdstrat_shut(bp
, _RET_IP_
);
1161 xfs_bioerror_relse(bp
);
1165 xfs_buf_iorequest(bp
);
1173 if (atomic_dec_and_test(&bp
->b_io_remaining
) == 1)
1174 xfs_buf_ioend(bp
, schedule
);
1182 xfs_buf_t
*bp
= (xfs_buf_t
*)bio
->bi_private
;
1184 xfs_buf_ioerror(bp
, -error
);
1186 if (!error
&& xfs_buf_is_vmapped(bp
) && (bp
->b_flags
& XBF_READ
))
1187 invalidate_kernel_vmap_range(bp
->b_addr
, xfs_buf_vmap_len(bp
));
1189 _xfs_buf_ioend(bp
, 1);
1197 int rw
, map_i
, total_nr_pages
, nr_pages
;
1199 int offset
= bp
->b_offset
;
1200 int size
= bp
->b_count_desired
;
1201 sector_t sector
= bp
->b_bn
;
1203 total_nr_pages
= bp
->b_page_count
;
1206 if (bp
->b_flags
& XBF_WRITE
) {
1207 if (bp
->b_flags
& XBF_SYNCIO
)
1211 if (bp
->b_flags
& XBF_FUA
)
1213 if (bp
->b_flags
& XBF_FLUSH
)
1215 } else if (bp
->b_flags
& XBF_READ_AHEAD
) {
1221 /* we only use the buffer cache for meta-data */
1225 atomic_inc(&bp
->b_io_remaining
);
1226 nr_pages
= BIO_MAX_SECTORS
>> (PAGE_SHIFT
- BBSHIFT
);
1227 if (nr_pages
> total_nr_pages
)
1228 nr_pages
= total_nr_pages
;
1230 bio
= bio_alloc(GFP_NOIO
, nr_pages
);
1231 bio
->bi_bdev
= bp
->b_target
->bt_bdev
;
1232 bio
->bi_sector
= sector
;
1233 bio
->bi_end_io
= xfs_buf_bio_end_io
;
1234 bio
->bi_private
= bp
;
1237 for (; size
&& nr_pages
; nr_pages
--, map_i
++) {
1238 int rbytes
, nbytes
= PAGE_SIZE
- offset
;
1243 rbytes
= bio_add_page(bio
, bp
->b_pages
[map_i
], nbytes
, offset
);
1244 if (rbytes
< nbytes
)
1248 sector
+= nbytes
>> BBSHIFT
;
1253 if (likely(bio
->bi_size
)) {
1254 if (xfs_buf_is_vmapped(bp
)) {
1255 flush_kernel_vmap_range(bp
->b_addr
,
1256 xfs_buf_vmap_len(bp
));
1258 submit_bio(rw
, bio
);
1262 xfs_buf_ioerror(bp
, EIO
);
1271 trace_xfs_buf_iorequest(bp
, _RET_IP_
);
1273 ASSERT(!(bp
->b_flags
& XBF_DELWRI
));
1275 if (bp
->b_flags
& XBF_WRITE
)
1276 xfs_buf_wait_unpin(bp
);
1279 /* Set the count to 1 initially, this will stop an I/O
1280 * completion callout which happens before we have started
1281 * all the I/O from calling xfs_buf_ioend too early.
1283 atomic_set(&bp
->b_io_remaining
, 1);
1284 _xfs_buf_ioapply(bp
);
1285 _xfs_buf_ioend(bp
, 0);
1292 * Waits for I/O to complete on the buffer supplied.
1293 * It returns immediately if no I/O is pending.
1294 * It returns the I/O error code, if any, or 0 if there was no error.
1300 trace_xfs_buf_iowait(bp
, _RET_IP_
);
1302 wait_for_completion(&bp
->b_iowait
);
1304 trace_xfs_buf_iowait_done(bp
, _RET_IP_
);
1315 if (bp
->b_flags
& XBF_MAPPED
)
1316 return bp
->b_addr
+ offset
;
1318 offset
+= bp
->b_offset
;
1319 page
= bp
->b_pages
[offset
>> PAGE_SHIFT
];
1320 return (xfs_caddr_t
)page_address(page
) + (offset
& (PAGE_SIZE
-1));
1324 * Move data into or out of a buffer.
1328 xfs_buf_t
*bp
, /* buffer to process */
1329 size_t boff
, /* starting buffer offset */
1330 size_t bsize
, /* length to copy */
1331 void *data
, /* data address */
1332 xfs_buf_rw_t mode
) /* read/write/zero flag */
1334 size_t bend
, cpoff
, csize
;
1337 bend
= boff
+ bsize
;
1338 while (boff
< bend
) {
1339 page
= bp
->b_pages
[xfs_buf_btoct(boff
+ bp
->b_offset
)];
1340 cpoff
= xfs_buf_poff(boff
+ bp
->b_offset
);
1341 csize
= min_t(size_t,
1342 PAGE_SIZE
-cpoff
, bp
->b_count_desired
-boff
);
1344 ASSERT(((csize
+ cpoff
) <= PAGE_SIZE
));
1348 memset(page_address(page
) + cpoff
, 0, csize
);
1351 memcpy(data
, page_address(page
) + cpoff
, csize
);
1354 memcpy(page_address(page
) + cpoff
, data
, csize
);
1363 * Handling of buffer targets (buftargs).
1367 * Wait for any bufs with callbacks that have been submitted but have not yet
1368 * returned. These buffers will have an elevated hold count, so wait on those
1369 * while freeing all the buffers only held by the LRU.
1373 struct xfs_buftarg
*btp
)
1378 spin_lock(&btp
->bt_lru_lock
);
1379 while (!list_empty(&btp
->bt_lru
)) {
1380 bp
= list_first_entry(&btp
->bt_lru
, struct xfs_buf
, b_lru
);
1381 if (atomic_read(&bp
->b_hold
) > 1) {
1382 spin_unlock(&btp
->bt_lru_lock
);
1387 * clear the LRU reference count so the bufer doesn't get
1388 * ignored in xfs_buf_rele().
1390 atomic_set(&bp
->b_lru_ref
, 0);
1391 spin_unlock(&btp
->bt_lru_lock
);
1393 spin_lock(&btp
->bt_lru_lock
);
1395 spin_unlock(&btp
->bt_lru_lock
);
1400 struct shrinker
*shrink
,
1401 struct shrink_control
*sc
)
1403 struct xfs_buftarg
*btp
= container_of(shrink
,
1404 struct xfs_buftarg
, bt_shrinker
);
1406 int nr_to_scan
= sc
->nr_to_scan
;
1410 return btp
->bt_lru_nr
;
1412 spin_lock(&btp
->bt_lru_lock
);
1413 while (!list_empty(&btp
->bt_lru
)) {
1414 if (nr_to_scan
-- <= 0)
1417 bp
= list_first_entry(&btp
->bt_lru
, struct xfs_buf
, b_lru
);
1420 * Decrement the b_lru_ref count unless the value is already
1421 * zero. If the value is already zero, we need to reclaim the
1422 * buffer, otherwise it gets another trip through the LRU.
1424 if (!atomic_add_unless(&bp
->b_lru_ref
, -1, 0)) {
1425 list_move_tail(&bp
->b_lru
, &btp
->bt_lru
);
1430 * remove the buffer from the LRU now to avoid needing another
1431 * lock round trip inside xfs_buf_rele().
1433 list_move(&bp
->b_lru
, &dispose
);
1436 spin_unlock(&btp
->bt_lru_lock
);
1438 while (!list_empty(&dispose
)) {
1439 bp
= list_first_entry(&dispose
, struct xfs_buf
, b_lru
);
1440 list_del_init(&bp
->b_lru
);
1444 return btp
->bt_lru_nr
;
1449 struct xfs_mount
*mp
,
1450 struct xfs_buftarg
*btp
)
1452 unregister_shrinker(&btp
->bt_shrinker
);
1454 xfs_flush_buftarg(btp
, 1);
1455 if (mp
->m_flags
& XFS_MOUNT_BARRIER
)
1456 xfs_blkdev_issue_flush(btp
);
1458 kthread_stop(btp
->bt_task
);
1463 xfs_setsize_buftarg_flags(
1465 unsigned int blocksize
,
1466 unsigned int sectorsize
,
1469 btp
->bt_bsize
= blocksize
;
1470 btp
->bt_sshift
= ffs(sectorsize
) - 1;
1471 btp
->bt_smask
= sectorsize
- 1;
1473 if (set_blocksize(btp
->bt_bdev
, sectorsize
)) {
1474 xfs_warn(btp
->bt_mount
,
1475 "Cannot set_blocksize to %u on device %s\n",
1476 sectorsize
, xfs_buf_target_name(btp
));
1484 * When allocating the initial buffer target we have not yet
1485 * read in the superblock, so don't know what sized sectors
1486 * are being used is at this early stage. Play safe.
1489 xfs_setsize_buftarg_early(
1491 struct block_device
*bdev
)
1493 return xfs_setsize_buftarg_flags(btp
,
1494 PAGE_SIZE
, bdev_logical_block_size(bdev
), 0);
1498 xfs_setsize_buftarg(
1500 unsigned int blocksize
,
1501 unsigned int sectorsize
)
1503 return xfs_setsize_buftarg_flags(btp
, blocksize
, sectorsize
, 1);
1507 xfs_alloc_delwrite_queue(
1511 INIT_LIST_HEAD(&btp
->bt_delwrite_queue
);
1512 spin_lock_init(&btp
->bt_delwrite_lock
);
1514 btp
->bt_task
= kthread_run(xfsbufd
, btp
, "xfsbufd/%s", fsname
);
1515 if (IS_ERR(btp
->bt_task
))
1516 return PTR_ERR(btp
->bt_task
);
1522 struct xfs_mount
*mp
,
1523 struct block_device
*bdev
,
1529 btp
= kmem_zalloc(sizeof(*btp
), KM_SLEEP
);
1532 btp
->bt_dev
= bdev
->bd_dev
;
1533 btp
->bt_bdev
= bdev
;
1534 btp
->bt_bdi
= blk_get_backing_dev_info(bdev
);
1538 INIT_LIST_HEAD(&btp
->bt_lru
);
1539 spin_lock_init(&btp
->bt_lru_lock
);
1540 if (xfs_setsize_buftarg_early(btp
, bdev
))
1542 if (xfs_alloc_delwrite_queue(btp
, fsname
))
1544 btp
->bt_shrinker
.shrink
= xfs_buftarg_shrink
;
1545 btp
->bt_shrinker
.seeks
= DEFAULT_SEEKS
;
1546 register_shrinker(&btp
->bt_shrinker
);
1556 * Delayed write buffer handling
1559 xfs_buf_delwri_queue(
1562 struct list_head
*dwq
= &bp
->b_target
->bt_delwrite_queue
;
1563 spinlock_t
*dwlk
= &bp
->b_target
->bt_delwrite_lock
;
1565 trace_xfs_buf_delwri_queue(bp
, _RET_IP_
);
1567 ASSERT(!(bp
->b_flags
& XBF_READ
));
1570 if (!list_empty(&bp
->b_list
)) {
1571 /* if already in the queue, move it to the tail */
1572 ASSERT(bp
->b_flags
& _XBF_DELWRI_Q
);
1573 list_move_tail(&bp
->b_list
, dwq
);
1575 /* start xfsbufd as it is about to have something to do */
1576 if (list_empty(dwq
))
1577 wake_up_process(bp
->b_target
->bt_task
);
1579 atomic_inc(&bp
->b_hold
);
1580 bp
->b_flags
|= XBF_DELWRI
| _XBF_DELWRI_Q
| XBF_ASYNC
;
1581 list_add_tail(&bp
->b_list
, dwq
);
1583 bp
->b_queuetime
= jiffies
;
1588 xfs_buf_delwri_dequeue(
1591 spinlock_t
*dwlk
= &bp
->b_target
->bt_delwrite_lock
;
1595 if ((bp
->b_flags
& XBF_DELWRI
) && !list_empty(&bp
->b_list
)) {
1596 ASSERT(bp
->b_flags
& _XBF_DELWRI_Q
);
1597 list_del_init(&bp
->b_list
);
1600 bp
->b_flags
&= ~(XBF_DELWRI
|_XBF_DELWRI_Q
);
1606 trace_xfs_buf_delwri_dequeue(bp
, _RET_IP_
);
1610 * If a delwri buffer needs to be pushed before it has aged out, then promote
1611 * it to the head of the delwri queue so that it will be flushed on the next
1612 * xfsbufd run. We do this by resetting the queuetime of the buffer to be older
1613 * than the age currently needed to flush the buffer. Hence the next time the
1614 * xfsbufd sees it is guaranteed to be considered old enough to flush.
1617 xfs_buf_delwri_promote(
1620 struct xfs_buftarg
*btp
= bp
->b_target
;
1621 long age
= xfs_buf_age_centisecs
* msecs_to_jiffies(10) + 1;
1623 ASSERT(bp
->b_flags
& XBF_DELWRI
);
1624 ASSERT(bp
->b_flags
& _XBF_DELWRI_Q
);
1627 * Check the buffer age before locking the delayed write queue as we
1628 * don't need to promote buffers that are already past the flush age.
1630 if (bp
->b_queuetime
< jiffies
- age
)
1632 bp
->b_queuetime
= jiffies
- age
;
1633 spin_lock(&btp
->bt_delwrite_lock
);
1634 list_move(&bp
->b_list
, &btp
->bt_delwrite_queue
);
1635 spin_unlock(&btp
->bt_delwrite_lock
);
1639 xfs_buf_runall_queues(
1640 struct workqueue_struct
*queue
)
1642 flush_workqueue(queue
);
1646 * Move as many buffers as specified to the supplied list
1647 * idicating if we skipped any buffers to prevent deadlocks.
1650 xfs_buf_delwri_split(
1651 xfs_buftarg_t
*target
,
1652 struct list_head
*list
,
1656 struct list_head
*dwq
= &target
->bt_delwrite_queue
;
1657 spinlock_t
*dwlk
= &target
->bt_delwrite_lock
;
1661 force
= test_and_clear_bit(XBT_FORCE_FLUSH
, &target
->bt_flags
);
1662 INIT_LIST_HEAD(list
);
1664 list_for_each_entry_safe(bp
, n
, dwq
, b_list
) {
1665 ASSERT(bp
->b_flags
& XBF_DELWRI
);
1667 if (!xfs_buf_ispinned(bp
) && xfs_buf_trylock(bp
)) {
1669 time_before(jiffies
, bp
->b_queuetime
+ age
)) {
1674 bp
->b_flags
&= ~(XBF_DELWRI
| _XBF_DELWRI_Q
);
1675 bp
->b_flags
|= XBF_WRITE
;
1676 list_move_tail(&bp
->b_list
, list
);
1677 trace_xfs_buf_delwri_split(bp
, _RET_IP_
);
1688 * Compare function is more complex than it needs to be because
1689 * the return value is only 32 bits and we are doing comparisons
1695 struct list_head
*a
,
1696 struct list_head
*b
)
1698 struct xfs_buf
*ap
= container_of(a
, struct xfs_buf
, b_list
);
1699 struct xfs_buf
*bp
= container_of(b
, struct xfs_buf
, b_list
);
1702 diff
= ap
->b_bn
- bp
->b_bn
;
1714 xfs_buftarg_t
*target
= (xfs_buftarg_t
*)data
;
1716 current
->flags
|= PF_MEMALLOC
;
1721 long age
= xfs_buf_age_centisecs
* msecs_to_jiffies(10);
1722 long tout
= xfs_buf_timer_centisecs
* msecs_to_jiffies(10);
1723 struct list_head tmp
;
1724 struct blk_plug plug
;
1726 if (unlikely(freezing(current
))) {
1727 set_bit(XBT_FORCE_SLEEP
, &target
->bt_flags
);
1730 clear_bit(XBT_FORCE_SLEEP
, &target
->bt_flags
);
1733 /* sleep for a long time if there is nothing to do. */
1734 if (list_empty(&target
->bt_delwrite_queue
))
1735 tout
= MAX_SCHEDULE_TIMEOUT
;
1736 schedule_timeout_interruptible(tout
);
1738 xfs_buf_delwri_split(target
, &tmp
, age
);
1739 list_sort(NULL
, &tmp
, xfs_buf_cmp
);
1741 blk_start_plug(&plug
);
1742 while (!list_empty(&tmp
)) {
1744 bp
= list_first_entry(&tmp
, struct xfs_buf
, b_list
);
1745 list_del_init(&bp
->b_list
);
1748 blk_finish_plug(&plug
);
1749 } while (!kthread_should_stop());
1755 * Go through all incore buffers, and release buffers if they belong to
1756 * the given device. This is used in filesystem error handling to
1757 * preserve the consistency of its metadata.
1761 xfs_buftarg_t
*target
,
1766 LIST_HEAD(tmp_list
);
1767 LIST_HEAD(wait_list
);
1768 struct blk_plug plug
;
1770 xfs_buf_runall_queues(xfsconvertd_workqueue
);
1771 xfs_buf_runall_queues(xfsdatad_workqueue
);
1772 xfs_buf_runall_queues(xfslogd_workqueue
);
1774 set_bit(XBT_FORCE_FLUSH
, &target
->bt_flags
);
1775 pincount
= xfs_buf_delwri_split(target
, &tmp_list
, 0);
1778 * Dropped the delayed write list lock, now walk the temporary list.
1779 * All I/O is issued async and then if we need to wait for completion
1780 * we do that after issuing all the IO.
1782 list_sort(NULL
, &tmp_list
, xfs_buf_cmp
);
1784 blk_start_plug(&plug
);
1785 while (!list_empty(&tmp_list
)) {
1786 bp
= list_first_entry(&tmp_list
, struct xfs_buf
, b_list
);
1787 ASSERT(target
== bp
->b_target
);
1788 list_del_init(&bp
->b_list
);
1790 bp
->b_flags
&= ~XBF_ASYNC
;
1791 list_add(&bp
->b_list
, &wait_list
);
1795 blk_finish_plug(&plug
);
1798 /* Wait for IO to complete. */
1799 while (!list_empty(&wait_list
)) {
1800 bp
= list_first_entry(&wait_list
, struct xfs_buf
, b_list
);
1802 list_del_init(&bp
->b_list
);
1814 xfs_buf_zone
= kmem_zone_init_flags(sizeof(xfs_buf_t
), "xfs_buf",
1815 KM_ZONE_HWALIGN
, NULL
);
1819 xfslogd_workqueue
= alloc_workqueue("xfslogd",
1820 WQ_MEM_RECLAIM
| WQ_HIGHPRI
, 1);
1821 if (!xfslogd_workqueue
)
1822 goto out_free_buf_zone
;
1824 xfsdatad_workqueue
= alloc_workqueue("xfsdatad", WQ_MEM_RECLAIM
, 1);
1825 if (!xfsdatad_workqueue
)
1826 goto out_destroy_xfslogd_workqueue
;
1828 xfsconvertd_workqueue
= alloc_workqueue("xfsconvertd",
1830 if (!xfsconvertd_workqueue
)
1831 goto out_destroy_xfsdatad_workqueue
;
1835 out_destroy_xfsdatad_workqueue
:
1836 destroy_workqueue(xfsdatad_workqueue
);
1837 out_destroy_xfslogd_workqueue
:
1838 destroy_workqueue(xfslogd_workqueue
);
1840 kmem_zone_destroy(xfs_buf_zone
);
1846 xfs_buf_terminate(void)
1848 destroy_workqueue(xfsconvertd_workqueue
);
1849 destroy_workqueue(xfsdatad_workqueue
);
1850 destroy_workqueue(xfslogd_workqueue
);
1851 kmem_zone_destroy(xfs_buf_zone
);
1854 #ifdef CONFIG_KDB_MODULES
1856 xfs_get_buftarg_list(void)
1858 return &xfs_buftarg_list
;