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>
41 #include "xfs_dmapi.h"
42 #include "xfs_mount.h"
43 #include "xfs_trace.h"
45 static kmem_zone_t *xfs_buf_zone;
46 STATIC int xfsbufd(void *);
47 STATIC int xfsbufd_wakeup(int, gfp_t);
48 STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int);
49 static struct shrinker xfs_buf_shake = {
50 .shrink = xfsbufd_wakeup,
51 .seeks = DEFAULT_SEEKS,
54 static struct workqueue_struct *xfslogd_workqueue;
55 struct workqueue_struct *xfsdatad_workqueue;
56 struct workqueue_struct *xfsconvertd_workqueue;
58 #ifdef XFS_BUF_LOCK_TRACKING
59 # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid)
60 # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1)
61 # define XB_GET_OWNER(bp) ((bp)->b_last_holder)
63 # define XB_SET_OWNER(bp) do { } while (0)
64 # define XB_CLEAR_OWNER(bp) do { } while (0)
65 # define XB_GET_OWNER(bp) do { } while (0)
68 #define xb_to_gfp(flags) \
69 ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \
70 ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN)
72 #define xb_to_km(flags) \
73 (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP)
75 #define xfs_buf_allocate(flags) \
76 kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags))
77 #define xfs_buf_deallocate(bp) \
78 kmem_zone_free(xfs_buf_zone, (bp));
85 * Return true if the buffer is vmapped.
87 * The XBF_MAPPED flag is set if the buffer should be mapped, but the
88 * code is clever enough to know it doesn't have to map a single page,
89 * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1.
91 return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1;
98 return (bp->b_page_count * PAGE_SIZE) - bp->b_offset;
102 * Page Region interfaces.
104 * For pages in filesystems where the blocksize is smaller than the
105 * pagesize, we use the page->private field (long) to hold a bitmap
106 * of uptodate regions within the page.
108 * Each such region is "bytes per page / bits per long" bytes long.
110 * NBPPR == number-of-bytes-per-page-region
111 * BTOPR == bytes-to-page-region (rounded up)
112 * BTOPRT == bytes-to-page-region-truncated (rounded down)
114 #if (BITS_PER_LONG == 32)
115 #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */
116 #elif (BITS_PER_LONG == 64)
117 #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */
119 #error BITS_PER_LONG must be 32 or 64
121 #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG)
122 #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT)
123 #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT))
133 first = BTOPR(offset);
134 final = BTOPRT(offset + length - 1);
135 first = min(first, final);
138 mask <<= BITS_PER_LONG - (final - first);
139 mask >>= BITS_PER_LONG - (final);
141 ASSERT(offset + length <= PAGE_CACHE_SIZE);
142 ASSERT((final - first) < BITS_PER_LONG && (final - first) >= 0);
153 set_page_private(page,
154 page_private(page) | page_region_mask(offset, length));
155 if (page_private(page) == ~0UL)
156 SetPageUptodate(page);
165 unsigned long mask = page_region_mask(offset, length);
167 return (mask && (page_private(page) & mask) == mask);
171 * Internal xfs_buf_t object manipulation
177 xfs_buftarg_t *target,
178 xfs_off_t range_base,
180 xfs_buf_flags_t flags)
183 * We don't want certain flags to appear in b_flags.
185 flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD);
187 memset(bp, 0, sizeof(xfs_buf_t));
188 atomic_set(&bp->b_hold, 1);
189 init_completion(&bp->b_iowait);
190 INIT_LIST_HEAD(&bp->b_list);
191 INIT_LIST_HEAD(&bp->b_hash_list);
192 init_MUTEX_LOCKED(&bp->b_sema); /* held, no waiters */
194 bp->b_target = target;
195 bp->b_file_offset = range_base;
197 * Set buffer_length and count_desired to the same value initially.
198 * I/O routines should use count_desired, which will be the same in
199 * most cases but may be reset (e.g. XFS recovery).
201 bp->b_buffer_length = bp->b_count_desired = range_length;
203 bp->b_bn = XFS_BUF_DADDR_NULL;
204 atomic_set(&bp->b_pin_count, 0);
205 init_waitqueue_head(&bp->b_waiters);
207 XFS_STATS_INC(xb_create);
209 trace_xfs_buf_init(bp, _RET_IP_);
213 * Allocate a page array capable of holding a specified number
214 * of pages, and point the page buf at it.
220 xfs_buf_flags_t flags)
222 /* Make sure that we have a page list */
223 if (bp->b_pages == NULL) {
224 bp->b_offset = xfs_buf_poff(bp->b_file_offset);
225 bp->b_page_count = page_count;
226 if (page_count <= XB_PAGES) {
227 bp->b_pages = bp->b_page_array;
229 bp->b_pages = kmem_alloc(sizeof(struct page *) *
230 page_count, xb_to_km(flags));
231 if (bp->b_pages == NULL)
234 memset(bp->b_pages, 0, sizeof(struct page *) * page_count);
240 * Frees b_pages if it was allocated.
246 if (bp->b_pages != bp->b_page_array) {
247 kmem_free(bp->b_pages);
253 * Releases the specified buffer.
255 * The modification state of any associated pages is left unchanged.
256 * The buffer most not be on any hash - use xfs_buf_rele instead for
257 * hashed and refcounted buffers
263 trace_xfs_buf_free(bp, _RET_IP_);
265 ASSERT(list_empty(&bp->b_hash_list));
267 if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) {
270 if (xfs_buf_is_vmapped(bp))
271 vm_unmap_ram(bp->b_addr - bp->b_offset,
274 for (i = 0; i < bp->b_page_count; i++) {
275 struct page *page = bp->b_pages[i];
277 if (bp->b_flags & _XBF_PAGE_CACHE)
278 ASSERT(!PagePrivate(page));
279 page_cache_release(page);
282 _xfs_buf_free_pages(bp);
283 xfs_buf_deallocate(bp);
287 * Finds all pages for buffer in question and builds it's page list.
290 _xfs_buf_lookup_pages(
294 struct address_space *mapping = bp->b_target->bt_mapping;
295 size_t blocksize = bp->b_target->bt_bsize;
296 size_t size = bp->b_count_desired;
297 size_t nbytes, offset;
298 gfp_t gfp_mask = xb_to_gfp(flags);
299 unsigned short page_count, i;
304 end = bp->b_file_offset + bp->b_buffer_length;
305 page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset);
307 error = _xfs_buf_get_pages(bp, page_count, flags);
310 bp->b_flags |= _XBF_PAGE_CACHE;
312 offset = bp->b_offset;
313 first = bp->b_file_offset >> PAGE_CACHE_SHIFT;
315 for (i = 0; i < bp->b_page_count; i++) {
320 page = find_or_create_page(mapping, first + i, gfp_mask);
321 if (unlikely(page == NULL)) {
322 if (flags & XBF_READ_AHEAD) {
323 bp->b_page_count = i;
324 for (i = 0; i < bp->b_page_count; i++)
325 unlock_page(bp->b_pages[i]);
330 * This could deadlock.
332 * But until all the XFS lowlevel code is revamped to
333 * handle buffer allocation failures we can't do much.
335 if (!(++retries % 100))
337 "XFS: possible memory allocation "
338 "deadlock in %s (mode:0x%x)\n",
341 XFS_STATS_INC(xb_page_retries);
342 xfsbufd_wakeup(0, gfp_mask);
343 congestion_wait(BLK_RW_ASYNC, HZ/50);
347 XFS_STATS_INC(xb_page_found);
349 nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset);
352 ASSERT(!PagePrivate(page));
353 if (!PageUptodate(page)) {
355 if (blocksize >= PAGE_CACHE_SIZE) {
356 if (flags & XBF_READ)
357 bp->b_flags |= _XBF_PAGE_LOCKED;
358 } else if (!PagePrivate(page)) {
359 if (test_page_region(page, offset, nbytes))
364 bp->b_pages[i] = page;
368 if (!(bp->b_flags & _XBF_PAGE_LOCKED)) {
369 for (i = 0; i < bp->b_page_count; i++)
370 unlock_page(bp->b_pages[i]);
373 if (page_count == bp->b_page_count)
374 bp->b_flags |= XBF_DONE;
380 * Map buffer into kernel address-space if nessecary.
387 /* A single page buffer is always mappable */
388 if (bp->b_page_count == 1) {
389 bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset;
390 bp->b_flags |= XBF_MAPPED;
391 } else if (flags & XBF_MAPPED) {
392 bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count,
394 if (unlikely(bp->b_addr == NULL))
396 bp->b_addr += bp->b_offset;
397 bp->b_flags |= XBF_MAPPED;
404 * Finding and Reading Buffers
408 * Look up, and creates if absent, a lockable buffer for
409 * a given range of an inode. The buffer is returned
410 * locked. If other overlapping buffers exist, they are
411 * released before the new buffer is created and locked,
412 * which may imply that this call will block until those buffers
413 * are unlocked. No I/O is implied by this call.
417 xfs_buftarg_t *btp, /* block device target */
418 xfs_off_t ioff, /* starting offset of range */
419 size_t isize, /* length of range */
420 xfs_buf_flags_t flags,
423 xfs_off_t range_base;
428 range_base = (ioff << BBSHIFT);
429 range_length = (isize << BBSHIFT);
431 /* Check for IOs smaller than the sector size / not sector aligned */
432 ASSERT(!(range_length < (1 << btp->bt_sshift)));
433 ASSERT(!(range_base & (xfs_off_t)btp->bt_smask));
435 hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)];
437 spin_lock(&hash->bh_lock);
439 list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) {
440 ASSERT(btp == bp->b_target);
441 if (bp->b_file_offset == range_base &&
442 bp->b_buffer_length == range_length) {
444 * If we look at something, bring it to the
445 * front of the list for next time.
447 atomic_inc(&bp->b_hold);
448 list_move(&bp->b_hash_list, &hash->bh_list);
455 _xfs_buf_initialize(new_bp, btp, range_base,
456 range_length, flags);
457 new_bp->b_hash = hash;
458 list_add(&new_bp->b_hash_list, &hash->bh_list);
460 XFS_STATS_INC(xb_miss_locked);
463 spin_unlock(&hash->bh_lock);
467 spin_unlock(&hash->bh_lock);
469 /* Attempt to get the semaphore without sleeping,
470 * if this does not work then we need to drop the
471 * spinlock and do a hard attempt on the semaphore.
473 if (down_trylock(&bp->b_sema)) {
474 if (!(flags & XBF_TRYLOCK)) {
475 /* wait for buffer ownership */
477 XFS_STATS_INC(xb_get_locked_waited);
479 /* We asked for a trylock and failed, no need
480 * to look at file offset and length here, we
481 * know that this buffer at least overlaps our
482 * buffer and is locked, therefore our buffer
483 * either does not exist, or is this buffer.
486 XFS_STATS_INC(xb_busy_locked);
494 if (bp->b_flags & XBF_STALE) {
495 ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0);
496 bp->b_flags &= XBF_MAPPED;
499 trace_xfs_buf_find(bp, flags, _RET_IP_);
500 XFS_STATS_INC(xb_get_locked);
505 * Assembles a buffer covering the specified range.
506 * Storage in memory for all portions of the buffer will be allocated,
507 * although backing storage may not be.
511 xfs_buftarg_t *target,/* target for buffer */
512 xfs_off_t ioff, /* starting offset of range */
513 size_t isize, /* length of range */
514 xfs_buf_flags_t flags)
516 xfs_buf_t *bp, *new_bp;
519 new_bp = xfs_buf_allocate(flags);
520 if (unlikely(!new_bp))
523 bp = _xfs_buf_find(target, ioff, isize, flags, new_bp);
525 error = _xfs_buf_lookup_pages(bp, flags);
529 xfs_buf_deallocate(new_bp);
530 if (unlikely(bp == NULL))
534 for (i = 0; i < bp->b_page_count; i++)
535 mark_page_accessed(bp->b_pages[i]);
537 if (!(bp->b_flags & XBF_MAPPED)) {
538 error = _xfs_buf_map_pages(bp, flags);
539 if (unlikely(error)) {
540 printk(KERN_WARNING "%s: failed to map pages\n",
546 XFS_STATS_INC(xb_get);
549 * Always fill in the block number now, the mapped cases can do
550 * their own overlay of this later.
553 bp->b_count_desired = bp->b_buffer_length;
555 trace_xfs_buf_get(bp, flags, _RET_IP_);
559 if (flags & (XBF_LOCK | XBF_TRYLOCK))
568 xfs_buf_flags_t flags)
572 ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE)));
573 ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL);
575 bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \
576 XBF_READ_AHEAD | _XBF_RUN_QUEUES);
577 bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | \
578 XBF_READ_AHEAD | _XBF_RUN_QUEUES);
580 status = xfs_buf_iorequest(bp);
581 if (!status && !(flags & XBF_ASYNC))
582 status = xfs_buf_iowait(bp);
588 xfs_buftarg_t *target,
591 xfs_buf_flags_t flags)
597 bp = xfs_buf_get(target, ioff, isize, flags);
599 trace_xfs_buf_read(bp, flags, _RET_IP_);
601 if (!XFS_BUF_ISDONE(bp)) {
602 XFS_STATS_INC(xb_get_read);
603 _xfs_buf_read(bp, flags);
604 } else if (flags & XBF_ASYNC) {
606 * Read ahead call which is already satisfied,
611 /* We do not want read in the flags */
612 bp->b_flags &= ~XBF_READ;
619 if (flags & (XBF_LOCK | XBF_TRYLOCK))
626 * If we are not low on memory then do the readahead in a deadlock
631 xfs_buftarg_t *target,
634 xfs_buf_flags_t flags)
636 struct backing_dev_info *bdi;
638 bdi = target->bt_mapping->backing_dev_info;
639 if (bdi_read_congested(bdi))
642 flags |= (XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD);
643 xfs_buf_read(target, ioff, isize, flags);
649 xfs_buftarg_t *target)
653 bp = xfs_buf_allocate(0);
655 _xfs_buf_initialize(bp, target, 0, len, 0);
659 static inline struct page *
663 if ((!is_vmalloc_addr(addr))) {
664 return virt_to_page(addr);
666 return vmalloc_to_page(addr);
671 xfs_buf_associate_memory(
678 unsigned long pageaddr;
679 unsigned long offset;
683 pageaddr = (unsigned long)mem & PAGE_CACHE_MASK;
684 offset = (unsigned long)mem - pageaddr;
685 buflen = PAGE_CACHE_ALIGN(len + offset);
686 page_count = buflen >> PAGE_CACHE_SHIFT;
688 /* Free any previous set of page pointers */
690 _xfs_buf_free_pages(bp);
695 rval = _xfs_buf_get_pages(bp, page_count, XBF_DONT_BLOCK);
699 bp->b_offset = offset;
701 for (i = 0; i < bp->b_page_count; i++) {
702 bp->b_pages[i] = mem_to_page((void *)pageaddr);
703 pageaddr += PAGE_CACHE_SIZE;
706 bp->b_count_desired = len;
707 bp->b_buffer_length = buflen;
708 bp->b_flags |= XBF_MAPPED;
709 bp->b_flags &= ~_XBF_PAGE_LOCKED;
717 xfs_buftarg_t *target)
719 unsigned long page_count = PAGE_ALIGN(len) >> PAGE_SHIFT;
723 bp = xfs_buf_allocate(0);
724 if (unlikely(bp == NULL))
726 _xfs_buf_initialize(bp, target, 0, len, 0);
728 error = _xfs_buf_get_pages(bp, page_count, 0);
732 for (i = 0; i < page_count; i++) {
733 bp->b_pages[i] = alloc_page(GFP_KERNEL);
737 bp->b_flags |= _XBF_PAGES;
739 error = _xfs_buf_map_pages(bp, XBF_MAPPED);
740 if (unlikely(error)) {
741 printk(KERN_WARNING "%s: failed to map pages\n",
748 trace_xfs_buf_get_noaddr(bp, _RET_IP_);
753 __free_page(bp->b_pages[i]);
754 _xfs_buf_free_pages(bp);
756 xfs_buf_deallocate(bp);
762 * Increment reference count on buffer, to hold the buffer concurrently
763 * with another thread which may release (free) the buffer asynchronously.
764 * Must hold the buffer already to call this function.
770 trace_xfs_buf_hold(bp, _RET_IP_);
771 atomic_inc(&bp->b_hold);
775 * Releases a hold on the specified buffer. If the
776 * the hold count is 1, calls xfs_buf_free.
782 xfs_bufhash_t *hash = bp->b_hash;
784 trace_xfs_buf_rele(bp, _RET_IP_);
786 if (unlikely(!hash)) {
787 ASSERT(!bp->b_relse);
788 if (atomic_dec_and_test(&bp->b_hold))
793 ASSERT(atomic_read(&bp->b_hold) > 0);
794 if (atomic_dec_and_lock(&bp->b_hold, &hash->bh_lock)) {
796 atomic_inc(&bp->b_hold);
797 spin_unlock(&hash->bh_lock);
798 (*(bp->b_relse)) (bp);
799 } else if (bp->b_flags & XBF_FS_MANAGED) {
800 spin_unlock(&hash->bh_lock);
802 ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)));
803 list_del_init(&bp->b_hash_list);
804 spin_unlock(&hash->bh_lock);
812 * Mutual exclusion on buffers. Locking model:
814 * Buffers associated with inodes for which buffer locking
815 * is not enabled are not protected by semaphores, and are
816 * assumed to be exclusively owned by the caller. There is a
817 * spinlock in the buffer, used by the caller when concurrent
818 * access is possible.
822 * Locks a buffer object, if it is not already locked.
823 * Note that this in no way locks the underlying pages, so it is only
824 * useful for synchronizing concurrent use of buffer objects, not for
825 * synchronizing independent access to the underlying pages.
833 locked = down_trylock(&bp->b_sema) == 0;
837 trace_xfs_buf_cond_lock(bp, _RET_IP_);
838 return locked ? 0 : -EBUSY;
845 return bp->b_sema.count;
849 * Locks a buffer object.
850 * Note that this in no way locks the underlying pages, so it is only
851 * useful for synchronizing concurrent use of buffer objects, not for
852 * synchronizing independent access to the underlying pages.
858 trace_xfs_buf_lock(bp, _RET_IP_);
860 if (atomic_read(&bp->b_io_remaining))
861 blk_run_address_space(bp->b_target->bt_mapping);
865 trace_xfs_buf_lock_done(bp, _RET_IP_);
869 * Releases the lock on the buffer object.
870 * If the buffer is marked delwri but is not queued, do so before we
871 * unlock the buffer as we need to set flags correctly. We also need to
872 * take a reference for the delwri queue because the unlocker is going to
873 * drop their's and they don't know we just queued it.
879 if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) {
880 atomic_inc(&bp->b_hold);
881 bp->b_flags |= XBF_ASYNC;
882 xfs_buf_delwri_queue(bp, 0);
888 trace_xfs_buf_unlock(bp, _RET_IP_);
893 * Pinning Buffer Storage in Memory
894 * Ensure that no attempt to force a buffer to disk will succeed.
900 trace_xfs_buf_pin(bp, _RET_IP_);
901 atomic_inc(&bp->b_pin_count);
908 trace_xfs_buf_unpin(bp, _RET_IP_);
910 if (atomic_dec_and_test(&bp->b_pin_count))
911 wake_up_all(&bp->b_waiters);
918 return atomic_read(&bp->b_pin_count);
925 DECLARE_WAITQUEUE (wait, current);
927 if (atomic_read(&bp->b_pin_count) == 0)
930 add_wait_queue(&bp->b_waiters, &wait);
932 set_current_state(TASK_UNINTERRUPTIBLE);
933 if (atomic_read(&bp->b_pin_count) == 0)
935 if (atomic_read(&bp->b_io_remaining))
936 blk_run_address_space(bp->b_target->bt_mapping);
939 remove_wait_queue(&bp->b_waiters, &wait);
940 set_current_state(TASK_RUNNING);
944 * Buffer Utility Routines
949 struct work_struct *work)
952 container_of(work, xfs_buf_t, b_iodone_work);
955 * We can get an EOPNOTSUPP to ordered writes. Here we clear the
956 * ordered flag and reissue them. Because we can't tell the higher
957 * layers directly that they should not issue ordered I/O anymore, they
958 * need to check if the _XFS_BARRIER_FAILED flag was set during I/O completion.
960 if ((bp->b_error == EOPNOTSUPP) &&
961 (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) {
962 trace_xfs_buf_ordered_retry(bp, _RET_IP_);
963 bp->b_flags &= ~XBF_ORDERED;
964 bp->b_flags |= _XFS_BARRIER_FAILED;
965 xfs_buf_iorequest(bp);
966 } else if (bp->b_iodone)
967 (*(bp->b_iodone))(bp);
968 else if (bp->b_flags & XBF_ASYNC)
977 trace_xfs_buf_iodone(bp, _RET_IP_);
979 bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD);
980 if (bp->b_error == 0)
981 bp->b_flags |= XBF_DONE;
983 if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) {
985 INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work);
986 queue_work(xfslogd_workqueue, &bp->b_iodone_work);
988 xfs_buf_iodone_work(&bp->b_iodone_work);
991 complete(&bp->b_iowait);
1000 ASSERT(error >= 0 && error <= 0xffff);
1001 bp->b_error = (unsigned short)error;
1002 trace_xfs_buf_ioerror(bp, error, _RET_IP_);
1007 struct xfs_mount *mp,
1010 int iowait = (bp->b_flags & XBF_ASYNC) == 0;
1013 bp->b_strat = xfs_bdstrat_cb;
1015 bp->b_flags |= XBF_WRITE;
1017 bp->b_flags |= _XBF_RUN_QUEUES;
1019 xfs_buf_delwri_dequeue(bp);
1020 xfs_buf_iostrategy(bp);
1023 error = xfs_buf_iowait(bp);
1025 xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
1037 trace_xfs_buf_bdwrite(bp, _RET_IP_);
1039 bp->b_strat = xfs_bdstrat_cb;
1042 bp->b_flags &= ~XBF_READ;
1043 bp->b_flags |= (XBF_DELWRI | XBF_ASYNC);
1045 xfs_buf_delwri_queue(bp, 1);
1049 * Called when we want to stop a buffer from getting written or read.
1050 * We attach the EIO error, muck with its flags, and call biodone
1051 * so that the proper iodone callbacks get called.
1057 #ifdef XFSERRORDEBUG
1058 ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone);
1062 * No need to wait until the buffer is unpinned, we aren't flushing it.
1064 XFS_BUF_ERROR(bp, EIO);
1067 * We're calling biodone, so delete XBF_DONE flag.
1070 XFS_BUF_UNDELAYWRITE(bp);
1074 XFS_BUF_CLR_BDSTRAT_FUNC(bp);
1081 * Same as xfs_bioerror, except that we are releasing the buffer
1082 * here ourselves, and avoiding the biodone call.
1083 * This is meant for userdata errors; metadata bufs come with
1084 * iodone functions attached, so that we can track down errors.
1090 int64_t fl = XFS_BUF_BFLAGS(bp);
1092 * No need to wait until the buffer is unpinned.
1093 * We aren't flushing it.
1095 * chunkhold expects B_DONE to be set, whether
1096 * we actually finish the I/O or not. We don't want to
1097 * change that interface.
1100 XFS_BUF_UNDELAYWRITE(bp);
1103 XFS_BUF_CLR_IODONE_FUNC(bp);
1104 XFS_BUF_CLR_BDSTRAT_FUNC(bp);
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_ERROR(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_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 bp->b_flags &= ~_XBF_PAGE_LOCKED;
1175 xfs_buf_ioend(bp, schedule);
1184 xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private;
1185 unsigned int blocksize = bp->b_target->bt_bsize;
1186 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
1188 xfs_buf_ioerror(bp, -error);
1190 if (!error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ))
1191 invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp));
1194 struct page *page = bvec->bv_page;
1196 ASSERT(!PagePrivate(page));
1197 if (unlikely(bp->b_error)) {
1198 if (bp->b_flags & XBF_READ)
1199 ClearPageUptodate(page);
1200 } else if (blocksize >= PAGE_CACHE_SIZE) {
1201 SetPageUptodate(page);
1202 } else if (!PagePrivate(page) &&
1203 (bp->b_flags & _XBF_PAGE_CACHE)) {
1204 set_page_region(page, bvec->bv_offset, bvec->bv_len);
1207 if (--bvec >= bio->bi_io_vec)
1208 prefetchw(&bvec->bv_page->flags);
1210 if (bp->b_flags & _XBF_PAGE_LOCKED)
1212 } while (bvec >= bio->bi_io_vec);
1214 _xfs_buf_ioend(bp, 1);
1222 int rw, map_i, total_nr_pages, nr_pages;
1224 int offset = bp->b_offset;
1225 int size = bp->b_count_desired;
1226 sector_t sector = bp->b_bn;
1227 unsigned int blocksize = bp->b_target->bt_bsize;
1229 total_nr_pages = bp->b_page_count;
1232 if (bp->b_flags & XBF_ORDERED) {
1233 ASSERT(!(bp->b_flags & XBF_READ));
1235 } else if (bp->b_flags & XBF_LOG_BUFFER) {
1236 ASSERT(!(bp->b_flags & XBF_READ_AHEAD));
1237 bp->b_flags &= ~_XBF_RUN_QUEUES;
1238 rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC;
1239 } else if (bp->b_flags & _XBF_RUN_QUEUES) {
1240 ASSERT(!(bp->b_flags & XBF_READ_AHEAD));
1241 bp->b_flags &= ~_XBF_RUN_QUEUES;
1242 rw = (bp->b_flags & XBF_WRITE) ? WRITE_META : READ_META;
1244 rw = (bp->b_flags & XBF_WRITE) ? WRITE :
1245 (bp->b_flags & XBF_READ_AHEAD) ? READA : READ;
1248 /* Special code path for reading a sub page size buffer in --
1249 * we populate up the whole page, and hence the other metadata
1250 * in the same page. This optimization is only valid when the
1251 * filesystem block size is not smaller than the page size.
1253 if ((bp->b_buffer_length < PAGE_CACHE_SIZE) &&
1254 ((bp->b_flags & (XBF_READ|_XBF_PAGE_LOCKED)) ==
1255 (XBF_READ|_XBF_PAGE_LOCKED)) &&
1256 (blocksize >= PAGE_CACHE_SIZE)) {
1257 bio = bio_alloc(GFP_NOIO, 1);
1259 bio->bi_bdev = bp->b_target->bt_bdev;
1260 bio->bi_sector = sector - (offset >> BBSHIFT);
1261 bio->bi_end_io = xfs_buf_bio_end_io;
1262 bio->bi_private = bp;
1264 bio_add_page(bio, bp->b_pages[0], PAGE_CACHE_SIZE, 0);
1267 atomic_inc(&bp->b_io_remaining);
1273 atomic_inc(&bp->b_io_remaining);
1274 nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT);
1275 if (nr_pages > total_nr_pages)
1276 nr_pages = total_nr_pages;
1278 bio = bio_alloc(GFP_NOIO, nr_pages);
1279 bio->bi_bdev = bp->b_target->bt_bdev;
1280 bio->bi_sector = sector;
1281 bio->bi_end_io = xfs_buf_bio_end_io;
1282 bio->bi_private = bp;
1284 for (; size && nr_pages; nr_pages--, map_i++) {
1285 int rbytes, nbytes = PAGE_CACHE_SIZE - offset;
1290 rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset);
1291 if (rbytes < nbytes)
1295 sector += nbytes >> BBSHIFT;
1301 if (likely(bio->bi_size)) {
1302 if (xfs_buf_is_vmapped(bp)) {
1303 flush_kernel_vmap_range(bp->b_addr,
1304 xfs_buf_vmap_len(bp));
1306 submit_bio(rw, bio);
1311 xfs_buf_ioerror(bp, EIO);
1319 trace_xfs_buf_iorequest(bp, _RET_IP_);
1321 if (bp->b_flags & XBF_DELWRI) {
1322 xfs_buf_delwri_queue(bp, 1);
1326 if (bp->b_flags & XBF_WRITE) {
1327 xfs_buf_wait_unpin(bp);
1332 /* Set the count to 1 initially, this will stop an I/O
1333 * completion callout which happens before we have started
1334 * all the I/O from calling xfs_buf_ioend too early.
1336 atomic_set(&bp->b_io_remaining, 1);
1337 _xfs_buf_ioapply(bp);
1338 _xfs_buf_ioend(bp, 0);
1345 * Waits for I/O to complete on the buffer supplied.
1346 * It returns immediately if no I/O is pending.
1347 * It returns the I/O error code, if any, or 0 if there was no error.
1353 trace_xfs_buf_iowait(bp, _RET_IP_);
1355 if (atomic_read(&bp->b_io_remaining))
1356 blk_run_address_space(bp->b_target->bt_mapping);
1357 wait_for_completion(&bp->b_iowait);
1359 trace_xfs_buf_iowait_done(bp, _RET_IP_);
1370 if (bp->b_flags & XBF_MAPPED)
1371 return XFS_BUF_PTR(bp) + offset;
1373 offset += bp->b_offset;
1374 page = bp->b_pages[offset >> PAGE_CACHE_SHIFT];
1375 return (xfs_caddr_t)page_address(page) + (offset & (PAGE_CACHE_SIZE-1));
1379 * Move data into or out of a buffer.
1383 xfs_buf_t *bp, /* buffer to process */
1384 size_t boff, /* starting buffer offset */
1385 size_t bsize, /* length to copy */
1386 void *data, /* data address */
1387 xfs_buf_rw_t mode) /* read/write/zero flag */
1389 size_t bend, cpoff, csize;
1392 bend = boff + bsize;
1393 while (boff < bend) {
1394 page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)];
1395 cpoff = xfs_buf_poff(boff + bp->b_offset);
1396 csize = min_t(size_t,
1397 PAGE_CACHE_SIZE-cpoff, bp->b_count_desired-boff);
1399 ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE));
1403 memset(page_address(page) + cpoff, 0, csize);
1406 memcpy(data, page_address(page) + cpoff, csize);
1409 memcpy(page_address(page) + cpoff, data, csize);
1418 * Handling of buffer targets (buftargs).
1422 * Wait for any bufs with callbacks that have been submitted but
1423 * have not yet returned... walk the hash list for the target.
1430 xfs_bufhash_t *hash;
1433 for (i = 0; i < (1 << btp->bt_hashshift); i++) {
1434 hash = &btp->bt_hash[i];
1436 spin_lock(&hash->bh_lock);
1437 list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) {
1438 ASSERT(btp == bp->b_target);
1439 if (!(bp->b_flags & XBF_FS_MANAGED)) {
1440 spin_unlock(&hash->bh_lock);
1442 * Catch superblock reference count leaks
1445 BUG_ON(bp->b_bn == 0);
1450 spin_unlock(&hash->bh_lock);
1455 * Allocate buffer hash table for a given target.
1456 * For devices containing metadata (i.e. not the log/realtime devices)
1457 * we need to allocate a much larger hash table.
1466 btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */
1467 btp->bt_hashmask = (1 << btp->bt_hashshift) - 1;
1468 btp->bt_hash = kmem_zalloc_large((1 << btp->bt_hashshift) *
1469 sizeof(xfs_bufhash_t));
1470 for (i = 0; i < (1 << btp->bt_hashshift); i++) {
1471 spin_lock_init(&btp->bt_hash[i].bh_lock);
1472 INIT_LIST_HEAD(&btp->bt_hash[i].bh_list);
1480 kmem_free_large(btp->bt_hash);
1481 btp->bt_hash = NULL;
1485 * buftarg list for delwrite queue processing
1487 static LIST_HEAD(xfs_buftarg_list);
1488 static DEFINE_SPINLOCK(xfs_buftarg_lock);
1491 xfs_register_buftarg(
1494 spin_lock(&xfs_buftarg_lock);
1495 list_add(&btp->bt_list, &xfs_buftarg_list);
1496 spin_unlock(&xfs_buftarg_lock);
1500 xfs_unregister_buftarg(
1503 spin_lock(&xfs_buftarg_lock);
1504 list_del(&btp->bt_list);
1505 spin_unlock(&xfs_buftarg_lock);
1510 struct xfs_mount *mp,
1511 struct xfs_buftarg *btp)
1513 xfs_flush_buftarg(btp, 1);
1514 if (mp->m_flags & XFS_MOUNT_BARRIER)
1515 xfs_blkdev_issue_flush(btp);
1516 xfs_free_bufhash(btp);
1517 iput(btp->bt_mapping->host);
1519 /* Unregister the buftarg first so that we don't get a
1520 * wakeup finding a non-existent task
1522 xfs_unregister_buftarg(btp);
1523 kthread_stop(btp->bt_task);
1529 xfs_setsize_buftarg_flags(
1531 unsigned int blocksize,
1532 unsigned int sectorsize,
1535 btp->bt_bsize = blocksize;
1536 btp->bt_sshift = ffs(sectorsize) - 1;
1537 btp->bt_smask = sectorsize - 1;
1539 if (set_blocksize(btp->bt_bdev, sectorsize)) {
1541 "XFS: Cannot set_blocksize to %u on device %s\n",
1542 sectorsize, XFS_BUFTARG_NAME(btp));
1547 (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) {
1549 "XFS: %u byte sectors in use on device %s. "
1550 "This is suboptimal; %u or greater is ideal.\n",
1551 sectorsize, XFS_BUFTARG_NAME(btp),
1552 (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG);
1559 * When allocating the initial buffer target we have not yet
1560 * read in the superblock, so don't know what sized sectors
1561 * are being used is at this early stage. Play safe.
1564 xfs_setsize_buftarg_early(
1566 struct block_device *bdev)
1568 return xfs_setsize_buftarg_flags(btp,
1569 PAGE_CACHE_SIZE, bdev_logical_block_size(bdev), 0);
1573 xfs_setsize_buftarg(
1575 unsigned int blocksize,
1576 unsigned int sectorsize)
1578 return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1);
1582 xfs_mapping_buftarg(
1584 struct block_device *bdev)
1586 struct backing_dev_info *bdi;
1587 struct inode *inode;
1588 struct address_space *mapping;
1589 static const struct address_space_operations mapping_aops = {
1590 .sync_page = block_sync_page,
1591 .migratepage = fail_migrate_page,
1594 inode = new_inode(bdev->bd_inode->i_sb);
1597 "XFS: Cannot allocate mapping inode for device %s\n",
1598 XFS_BUFTARG_NAME(btp));
1601 inode->i_mode = S_IFBLK;
1602 inode->i_bdev = bdev;
1603 inode->i_rdev = bdev->bd_dev;
1604 bdi = blk_get_backing_dev_info(bdev);
1606 bdi = &default_backing_dev_info;
1607 mapping = &inode->i_data;
1608 mapping->a_ops = &mapping_aops;
1609 mapping->backing_dev_info = bdi;
1610 mapping_set_gfp_mask(mapping, GFP_NOFS);
1611 btp->bt_mapping = mapping;
1616 xfs_alloc_delwrite_queue(
1621 INIT_LIST_HEAD(&btp->bt_list);
1622 INIT_LIST_HEAD(&btp->bt_delwrite_queue);
1623 spin_lock_init(&btp->bt_delwrite_lock);
1625 btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd");
1626 if (IS_ERR(btp->bt_task)) {
1627 error = PTR_ERR(btp->bt_task);
1630 xfs_register_buftarg(btp);
1637 struct block_device *bdev,
1642 btp = kmem_zalloc(sizeof(*btp), KM_SLEEP);
1644 btp->bt_dev = bdev->bd_dev;
1645 btp->bt_bdev = bdev;
1646 if (xfs_setsize_buftarg_early(btp, bdev))
1648 if (xfs_mapping_buftarg(btp, bdev))
1650 if (xfs_alloc_delwrite_queue(btp))
1652 xfs_alloc_bufhash(btp, external);
1662 * Delayed write buffer handling
1665 xfs_buf_delwri_queue(
1669 struct list_head *dwq = &bp->b_target->bt_delwrite_queue;
1670 spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock;
1672 trace_xfs_buf_delwri_queue(bp, _RET_IP_);
1674 ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC));
1677 /* If already in the queue, dequeue and place at tail */
1678 if (!list_empty(&bp->b_list)) {
1679 ASSERT(bp->b_flags & _XBF_DELWRI_Q);
1681 atomic_dec(&bp->b_hold);
1682 list_del(&bp->b_list);
1685 if (list_empty(dwq)) {
1686 /* start xfsbufd as it is about to have something to do */
1687 wake_up_process(bp->b_target->bt_task);
1690 bp->b_flags |= _XBF_DELWRI_Q;
1691 list_add_tail(&bp->b_list, dwq);
1692 bp->b_queuetime = jiffies;
1700 xfs_buf_delwri_dequeue(
1703 spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock;
1707 if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) {
1708 ASSERT(bp->b_flags & _XBF_DELWRI_Q);
1709 list_del_init(&bp->b_list);
1712 bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q);
1718 trace_xfs_buf_delwri_dequeue(bp, _RET_IP_);
1722 * If a delwri buffer needs to be pushed before it has aged out, then promote
1723 * it to the head of the delwri queue so that it will be flushed on the next
1724 * xfsbufd run. We do this by resetting the queuetime of the buffer to be older
1725 * than the age currently needed to flush the buffer. Hence the next time the
1726 * xfsbufd sees it is guaranteed to be considered old enough to flush.
1729 xfs_buf_delwri_promote(
1732 struct xfs_buftarg *btp = bp->b_target;
1733 long age = xfs_buf_age_centisecs * msecs_to_jiffies(10) + 1;
1735 ASSERT(bp->b_flags & XBF_DELWRI);
1736 ASSERT(bp->b_flags & _XBF_DELWRI_Q);
1739 * Check the buffer age before locking the delayed write queue as we
1740 * don't need to promote buffers that are already past the flush age.
1742 if (bp->b_queuetime < jiffies - age)
1744 bp->b_queuetime = jiffies - age;
1745 spin_lock(&btp->bt_delwrite_lock);
1746 list_move(&bp->b_list, &btp->bt_delwrite_queue);
1747 spin_unlock(&btp->bt_delwrite_lock);
1751 xfs_buf_runall_queues(
1752 struct workqueue_struct *queue)
1754 flush_workqueue(queue);
1764 spin_lock(&xfs_buftarg_lock);
1765 list_for_each_entry(btp, &xfs_buftarg_list, bt_list) {
1766 if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags))
1768 if (list_empty(&btp->bt_delwrite_queue))
1770 set_bit(XBT_FORCE_FLUSH, &btp->bt_flags);
1771 wake_up_process(btp->bt_task);
1773 spin_unlock(&xfs_buftarg_lock);
1778 * Move as many buffers as specified to the supplied list
1779 * idicating if we skipped any buffers to prevent deadlocks.
1782 xfs_buf_delwri_split(
1783 xfs_buftarg_t *target,
1784 struct list_head *list,
1788 struct list_head *dwq = &target->bt_delwrite_queue;
1789 spinlock_t *dwlk = &target->bt_delwrite_lock;
1793 force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags);
1794 INIT_LIST_HEAD(list);
1796 list_for_each_entry_safe(bp, n, dwq, b_list) {
1797 trace_xfs_buf_delwri_split(bp, _RET_IP_);
1798 ASSERT(bp->b_flags & XBF_DELWRI);
1800 if (!xfs_buf_ispin(bp) && !xfs_buf_cond_lock(bp)) {
1802 time_before(jiffies, bp->b_queuetime + age)) {
1807 bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q|
1809 bp->b_flags |= XBF_WRITE;
1810 list_move_tail(&bp->b_list, list);
1821 * Compare function is more complex than it needs to be because
1822 * the return value is only 32 bits and we are doing comparisons
1828 struct list_head *a,
1829 struct list_head *b)
1831 struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list);
1832 struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list);
1835 diff = ap->b_bn - bp->b_bn;
1844 xfs_buf_delwri_sort(
1845 xfs_buftarg_t *target,
1846 struct list_head *list)
1848 list_sort(NULL, list, xfs_buf_cmp);
1855 xfs_buftarg_t *target = (xfs_buftarg_t *)data;
1857 current->flags |= PF_MEMALLOC;
1862 long age = xfs_buf_age_centisecs * msecs_to_jiffies(10);
1863 long tout = xfs_buf_timer_centisecs * msecs_to_jiffies(10);
1865 struct list_head tmp;
1867 if (unlikely(freezing(current))) {
1868 set_bit(XBT_FORCE_SLEEP, &target->bt_flags);
1871 clear_bit(XBT_FORCE_SLEEP, &target->bt_flags);
1874 /* sleep for a long time if there is nothing to do. */
1875 if (list_empty(&target->bt_delwrite_queue))
1876 tout = MAX_SCHEDULE_TIMEOUT;
1877 schedule_timeout_interruptible(tout);
1879 xfs_buf_delwri_split(target, &tmp, age);
1880 list_sort(NULL, &tmp, xfs_buf_cmp);
1881 while (!list_empty(&tmp)) {
1883 bp = list_first_entry(&tmp, struct xfs_buf, b_list);
1884 list_del_init(&bp->b_list);
1885 xfs_buf_iostrategy(bp);
1889 blk_run_address_space(target->bt_mapping);
1891 } while (!kthread_should_stop());
1897 * Go through all incore buffers, and release buffers if they belong to
1898 * the given device. This is used in filesystem error handling to
1899 * preserve the consistency of its metadata.
1903 xfs_buftarg_t *target,
1908 LIST_HEAD(tmp_list);
1909 LIST_HEAD(wait_list);
1911 xfs_buf_runall_queues(xfsconvertd_workqueue);
1912 xfs_buf_runall_queues(xfsdatad_workqueue);
1913 xfs_buf_runall_queues(xfslogd_workqueue);
1915 set_bit(XBT_FORCE_FLUSH, &target->bt_flags);
1916 pincount = xfs_buf_delwri_split(target, &tmp_list, 0);
1919 * Dropped the delayed write list lock, now walk the temporary list.
1920 * All I/O is issued async and then if we need to wait for completion
1921 * we do that after issuing all the IO.
1923 list_sort(NULL, &tmp_list, xfs_buf_cmp);
1924 while (!list_empty(&tmp_list)) {
1925 bp = list_first_entry(&tmp_list, struct xfs_buf, b_list);
1926 ASSERT(target == bp->b_target);
1927 list_del_init(&bp->b_list);
1929 bp->b_flags &= ~XBF_ASYNC;
1930 list_add(&bp->b_list, &wait_list);
1932 xfs_buf_iostrategy(bp);
1936 /* Expedite and wait for IO to complete. */
1937 blk_run_address_space(target->bt_mapping);
1938 while (!list_empty(&wait_list)) {
1939 bp = list_first_entry(&wait_list, struct xfs_buf, b_list);
1941 list_del_init(&bp->b_list);
1953 xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf",
1954 KM_ZONE_HWALIGN, NULL);
1958 xfslogd_workqueue = create_workqueue("xfslogd");
1959 if (!xfslogd_workqueue)
1960 goto out_free_buf_zone;
1962 xfsdatad_workqueue = create_workqueue("xfsdatad");
1963 if (!xfsdatad_workqueue)
1964 goto out_destroy_xfslogd_workqueue;
1966 xfsconvertd_workqueue = create_workqueue("xfsconvertd");
1967 if (!xfsconvertd_workqueue)
1968 goto out_destroy_xfsdatad_workqueue;
1970 register_shrinker(&xfs_buf_shake);
1973 out_destroy_xfsdatad_workqueue:
1974 destroy_workqueue(xfsdatad_workqueue);
1975 out_destroy_xfslogd_workqueue:
1976 destroy_workqueue(xfslogd_workqueue);
1978 kmem_zone_destroy(xfs_buf_zone);
1984 xfs_buf_terminate(void)
1986 unregister_shrinker(&xfs_buf_shake);
1987 destroy_workqueue(xfsconvertd_workqueue);
1988 destroy_workqueue(xfsdatad_workqueue);
1989 destroy_workqueue(xfslogd_workqueue);
1990 kmem_zone_destroy(xfs_buf_zone);
1993 #ifdef CONFIG_KDB_MODULES
1995 xfs_get_buftarg_list(void)
1997 return &xfs_buftarg_list;