2 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
4 * bitmap_create - sets up the bitmap structure
5 * bitmap_destroy - destroys the bitmap structure
7 * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
8 * - added disk storage for bitmap
9 * - changes to allow various bitmap chunk sizes
10 * - added bitmap daemon (to asynchronously clear bitmap bits from disk)
16 * flush after percent set rather than just time based. (maybe both).
17 * wait if count gets too high, wake when it drops to half.
18 * allow bitmap to be mirrored with superblock (before or after...)
19 * allow hot-add to re-instate a current device.
20 * allow hot-add of bitmap after quiessing device
23 #include <linux/module.h>
24 #include <linux/version.h>
25 #include <linux/errno.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/config.h>
29 #include <linux/timer.h>
30 #include <linux/sched.h>
31 #include <linux/list.h>
32 #include <linux/file.h>
33 #include <linux/mount.h>
34 #include <linux/buffer_head.h>
35 #include <linux/raid/md.h>
36 #include <linux/raid/bitmap.h>
43 /* these are for debugging purposes only! */
45 /* define one and only one of these */
46 #define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */
47 #define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/
48 #define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */
49 #define INJECT_FAULTS_4 0 /* undef */
50 #define INJECT_FAULTS_5 0 /* undef */
51 #define INJECT_FAULTS_6 0
53 /* if these are defined, the driver will fail! debug only */
54 #define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */
55 #define INJECT_FATAL_FAULT_2 0 /* undef */
56 #define INJECT_FATAL_FAULT_3 0 /* undef */
59 //#define DPRINTK PRINTK /* set this NULL to avoid verbose debug output */
60 #define DPRINTK(x...) do { } while(0)
64 # define PRINTK(x...) printk(KERN_DEBUG x)
70 static inline char * bmname(struct bitmap
*bitmap
)
72 return bitmap
->mddev
? mdname(bitmap
->mddev
) : "mdX";
77 * test if the bitmap is active
79 int bitmap_active(struct bitmap
*bitmap
)
86 spin_lock_irqsave(&bitmap
->lock
, flags
);
87 res
= bitmap
->flags
& BITMAP_ACTIVE
;
88 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
92 #define WRITE_POOL_SIZE 256
93 /* mempool for queueing pending writes on the bitmap file */
94 static void *write_pool_alloc(unsigned int gfp_flags
, void *data
)
96 return kmalloc(sizeof(struct page_list
), gfp_flags
);
99 static void write_pool_free(void *ptr
, void *data
)
105 * just a placeholder - calls kmalloc for bitmap pages
107 static unsigned char *bitmap_alloc_page(struct bitmap
*bitmap
)
114 page
= kmalloc(PAGE_SIZE
, GFP_NOIO
);
117 printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap
));
119 printk("%s: bitmap_alloc_page: allocated page at %p\n",
120 bmname(bitmap
), page
);
125 * for now just a placeholder -- just calls kfree for bitmap pages
127 static void bitmap_free_page(struct bitmap
*bitmap
, unsigned char *page
)
129 PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap
), page
);
134 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
136 * 1) check to see if this page is allocated, if it's not then try to alloc
137 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
138 * page pointer directly as a counter
140 * if we find our page, we increment the page's refcount so that it stays
141 * allocated while we're using it
143 static int bitmap_checkpage(struct bitmap
*bitmap
, unsigned long page
, int create
)
145 unsigned char *mappage
;
147 if (page
>= bitmap
->pages
) {
149 "%s: invalid bitmap page request: %lu (> %lu)\n",
150 bmname(bitmap
), page
, bitmap
->pages
-1);
155 if (bitmap
->bp
[page
].hijacked
) /* it's hijacked, don't try to alloc */
158 if (bitmap
->bp
[page
].map
) /* page is already allocated, just return */
164 spin_unlock_irq(&bitmap
->lock
);
166 /* this page has not been allocated yet */
168 if ((mappage
= bitmap_alloc_page(bitmap
)) == NULL
) {
169 PRINTK("%s: bitmap map page allocation failed, hijacking\n",
171 /* failed - set the hijacked flag so that we can use the
172 * pointer as a counter */
173 spin_lock_irq(&bitmap
->lock
);
174 if (!bitmap
->bp
[page
].map
)
175 bitmap
->bp
[page
].hijacked
= 1;
181 spin_lock_irq(&bitmap
->lock
);
183 /* recheck the page */
185 if (bitmap
->bp
[page
].map
|| bitmap
->bp
[page
].hijacked
) {
186 /* somebody beat us to getting the page */
187 bitmap_free_page(bitmap
, mappage
);
191 /* no page was in place and we have one, so install it */
193 memset(mappage
, 0, PAGE_SIZE
);
194 bitmap
->bp
[page
].map
= mappage
;
195 bitmap
->missing_pages
--;
201 /* if page is completely empty, put it back on the free list, or dealloc it */
202 /* if page was hijacked, unmark the flag so it might get alloced next time */
203 /* Note: lock should be held when calling this */
204 static inline void bitmap_checkfree(struct bitmap
*bitmap
, unsigned long page
)
208 if (bitmap
->bp
[page
].count
) /* page is still busy */
211 /* page is no longer in use, it can be released */
213 if (bitmap
->bp
[page
].hijacked
) { /* page was hijacked, undo this now */
214 bitmap
->bp
[page
].hijacked
= 0;
215 bitmap
->bp
[page
].map
= NULL
;
219 /* normal case, free the page */
222 /* actually ... let's not. We will probably need the page again exactly when
223 * memory is tight and we are flusing to disk
227 ptr
= bitmap
->bp
[page
].map
;
228 bitmap
->bp
[page
].map
= NULL
;
229 bitmap
->missing_pages
++;
230 bitmap_free_page(bitmap
, ptr
);
237 * bitmap file handling - read and write the bitmap file and its superblock
240 /* copy the pathname of a file to a buffer */
241 char *file_path(struct file
*file
, char *buf
, int count
)
252 buf
= d_path(d
, v
, buf
, count
);
254 return IS_ERR(buf
) ? NULL
: buf
;
258 * basic page I/O operations
264 static int write_page(struct bitmap
*bitmap
, struct page
*page
, int wait
)
270 ret
= page
->mapping
->a_ops
->prepare_write(NULL
, page
, 0, PAGE_SIZE
);
272 ret
= page
->mapping
->a_ops
->commit_write(NULL
, page
, 0,
279 set_page_dirty(page
); /* force it to be written out */
282 /* add to list to be waited for by daemon */
283 struct page_list
*item
= mempool_alloc(bitmap
->write_pool
, GFP_NOIO
);
285 page_cache_get(page
);
286 spin_lock(&bitmap
->write_lock
);
287 list_add(&item
->list
, &bitmap
->complete_pages
);
288 spin_unlock(&bitmap
->write_lock
);
289 md_wakeup_thread(bitmap
->writeback_daemon
);
291 return write_one_page(page
, wait
);
294 /* read a page from a file, pinning it into cache, and return bytes_read */
295 static struct page
*read_page(struct file
*file
, unsigned long index
,
296 unsigned long *bytes_read
)
298 struct inode
*inode
= file
->f_mapping
->host
;
299 struct page
*page
= NULL
;
300 loff_t isize
= i_size_read(inode
);
301 unsigned long end_index
= isize
>> PAGE_CACHE_SHIFT
;
303 PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_CACHE_SIZE
,
304 (unsigned long long)index
<< PAGE_CACHE_SHIFT
);
306 page
= read_cache_page(inode
->i_mapping
, index
,
307 (filler_t
*)inode
->i_mapping
->a_ops
->readpage
, file
);
310 wait_on_page_locked(page
);
311 if (!PageUptodate(page
) || PageError(page
)) {
312 page_cache_release(page
);
313 page
= ERR_PTR(-EIO
);
317 if (index
> end_index
) /* we have read beyond EOF */
319 else if (index
== end_index
) /* possible short read */
320 *bytes_read
= isize
& ~PAGE_CACHE_MASK
;
322 *bytes_read
= PAGE_CACHE_SIZE
; /* got a full page */
325 printk(KERN_ALERT
"md: bitmap read error: (%dB @ %Lu): %ld\n",
326 (int)PAGE_CACHE_SIZE
,
327 (unsigned long long)index
<< PAGE_CACHE_SHIFT
,
333 * bitmap file superblock operations
336 /* update the event counter and sync the superblock to disk */
337 int bitmap_update_sb(struct bitmap
*bitmap
)
342 if (!bitmap
|| !bitmap
->mddev
) /* no bitmap for this array */
344 spin_lock_irqsave(&bitmap
->lock
, flags
);
345 if (!bitmap
->sb_page
) { /* no superblock */
346 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
349 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
350 sb
= (bitmap_super_t
*)kmap(bitmap
->sb_page
);
351 sb
->events
= cpu_to_le64(bitmap
->mddev
->events
);
352 if (!bitmap
->mddev
->degraded
)
353 sb
->events_cleared
= cpu_to_le64(bitmap
->mddev
->events
);
354 kunmap(bitmap
->sb_page
);
355 return write_page(bitmap
, bitmap
->sb_page
, 0);
358 /* print out the bitmap file superblock */
359 void bitmap_print_sb(struct bitmap
*bitmap
)
363 if (!bitmap
|| !bitmap
->sb_page
)
365 sb
= (bitmap_super_t
*)kmap(bitmap
->sb_page
);
366 printk(KERN_DEBUG
"%s: bitmap file superblock:\n", bmname(bitmap
));
367 printk(KERN_DEBUG
" magic: %08x\n", le32_to_cpu(sb
->magic
));
368 printk(KERN_DEBUG
" version: %d\n", le32_to_cpu(sb
->version
));
369 printk(KERN_DEBUG
" uuid: %08x.%08x.%08x.%08x\n",
370 *(__u32
*)(sb
->uuid
+0),
371 *(__u32
*)(sb
->uuid
+4),
372 *(__u32
*)(sb
->uuid
+8),
373 *(__u32
*)(sb
->uuid
+12));
374 printk(KERN_DEBUG
" events: %llu\n",
375 (unsigned long long) le64_to_cpu(sb
->events
));
376 printk(KERN_DEBUG
"events cleared: %llu\n",
377 (unsigned long long) le64_to_cpu(sb
->events_cleared
));
378 printk(KERN_DEBUG
" state: %08x\n", le32_to_cpu(sb
->state
));
379 printk(KERN_DEBUG
" chunksize: %d B\n", le32_to_cpu(sb
->chunksize
));
380 printk(KERN_DEBUG
" daemon sleep: %ds\n", le32_to_cpu(sb
->daemon_sleep
));
381 printk(KERN_DEBUG
" sync size: %llu KB\n",
382 (unsigned long long)le64_to_cpu(sb
->sync_size
)/2);
383 kunmap(bitmap
->sb_page
);
386 /* read the superblock from the bitmap file and initialize some bitmap fields */
387 static int bitmap_read_sb(struct bitmap
*bitmap
)
391 unsigned long chunksize
, daemon_sleep
;
392 unsigned long bytes_read
;
393 unsigned long long events
;
396 /* page 0 is the superblock, read it... */
397 bitmap
->sb_page
= read_page(bitmap
->file
, 0, &bytes_read
);
398 if (IS_ERR(bitmap
->sb_page
)) {
399 err
= PTR_ERR(bitmap
->sb_page
);
400 bitmap
->sb_page
= NULL
;
404 sb
= (bitmap_super_t
*)kmap(bitmap
->sb_page
);
406 if (bytes_read
< sizeof(*sb
)) { /* short read */
407 printk(KERN_INFO
"%s: bitmap file superblock truncated\n",
413 chunksize
= le32_to_cpu(sb
->chunksize
);
414 daemon_sleep
= le32_to_cpu(sb
->daemon_sleep
);
416 /* verify that the bitmap-specific fields are valid */
417 if (sb
->magic
!= cpu_to_le32(BITMAP_MAGIC
))
418 reason
= "bad magic";
419 else if (sb
->version
!= cpu_to_le32(BITMAP_MAJOR
))
420 reason
= "unrecognized superblock version";
421 else if (chunksize
< 512 || chunksize
> (1024 * 1024 * 4))
422 reason
= "bitmap chunksize out of range (512B - 4MB)";
423 else if ((1 << ffz(~chunksize
)) != chunksize
)
424 reason
= "bitmap chunksize not a power of 2";
425 else if (daemon_sleep
< 1 || daemon_sleep
> 15)
426 reason
= "daemon sleep period out of range";
428 printk(KERN_INFO
"%s: invalid bitmap file superblock: %s\n",
429 bmname(bitmap
), reason
);
433 /* keep the array size field of the bitmap superblock up to date */
434 sb
->sync_size
= cpu_to_le64(bitmap
->mddev
->resync_max_sectors
);
436 if (!bitmap
->mddev
->persistent
)
440 * if we have a persistent array superblock, compare the
441 * bitmap's UUID and event counter to the mddev's
443 if (memcmp(sb
->uuid
, bitmap
->mddev
->uuid
, 16)) {
444 printk(KERN_INFO
"%s: bitmap superblock UUID mismatch\n",
448 events
= le64_to_cpu(sb
->events
);
449 if (events
< bitmap
->mddev
->events
) {
450 printk(KERN_INFO
"%s: bitmap file is out of date (%llu < %llu) "
451 "-- forcing full recovery\n", bmname(bitmap
), events
,
452 (unsigned long long) bitmap
->mddev
->events
);
453 sb
->state
|= BITMAP_STALE
;
456 /* assign fields using values from superblock */
457 bitmap
->chunksize
= chunksize
;
458 bitmap
->daemon_sleep
= daemon_sleep
;
459 bitmap
->flags
|= sb
->state
;
460 bitmap
->events_cleared
= le64_to_cpu(sb
->events_cleared
);
463 kunmap(bitmap
->sb_page
);
465 bitmap_print_sb(bitmap
);
469 enum bitmap_mask_op
{
474 /* record the state of the bitmap in the superblock */
475 static void bitmap_mask_state(struct bitmap
*bitmap
, enum bitmap_state bits
,
476 enum bitmap_mask_op op
)
481 spin_lock_irqsave(&bitmap
->lock
, flags
);
482 if (!bitmap
|| !bitmap
->sb_page
) { /* can't set the state */
483 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
486 page_cache_get(bitmap
->sb_page
);
487 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
488 sb
= (bitmap_super_t
*)kmap(bitmap
->sb_page
);
490 case MASK_SET
: sb
->state
|= bits
;
492 case MASK_UNSET
: sb
->state
&= ~bits
;
496 kunmap(bitmap
->sb_page
);
497 page_cache_release(bitmap
->sb_page
);
501 * general bitmap file operations
504 /* calculate the index of the page that contains this bit */
505 static inline unsigned long file_page_index(unsigned long chunk
)
507 return CHUNK_BIT_OFFSET(chunk
) >> PAGE_BIT_SHIFT
;
510 /* calculate the (bit) offset of this bit within a page */
511 static inline unsigned long file_page_offset(unsigned long chunk
)
513 return CHUNK_BIT_OFFSET(chunk
) & (PAGE_BITS
- 1);
517 * return a pointer to the page in the filemap that contains the given bit
519 * this lookup is complicated by the fact that the bitmap sb might be exactly
520 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
523 static inline struct page
*filemap_get_page(struct bitmap
*bitmap
,
526 return bitmap
->filemap
[file_page_index(chunk
) - file_page_index(0)];
530 static void bitmap_file_unmap(struct bitmap
*bitmap
)
532 struct page
**map
, *sb_page
;
537 spin_lock_irqsave(&bitmap
->lock
, flags
);
538 map
= bitmap
->filemap
;
539 bitmap
->filemap
= NULL
;
540 attr
= bitmap
->filemap_attr
;
541 bitmap
->filemap_attr
= NULL
;
542 pages
= bitmap
->file_pages
;
543 bitmap
->file_pages
= 0;
544 sb_page
= bitmap
->sb_page
;
545 bitmap
->sb_page
= NULL
;
546 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
549 if (map
[pages
]->index
!= 0) /* 0 is sb_page, release it below */
550 page_cache_release(map
[pages
]);
555 page_cache_release(sb_page
);
558 static void bitmap_stop_daemons(struct bitmap
*bitmap
);
560 /* dequeue the next item in a page list -- don't call from irq context */
561 static struct page_list
*dequeue_page(struct bitmap
*bitmap
)
563 struct page_list
*item
= NULL
;
564 struct list_head
*head
= &bitmap
->complete_pages
;
566 spin_lock(&bitmap
->write_lock
);
567 if (list_empty(head
))
569 item
= list_entry(head
->prev
, struct page_list
, list
);
570 list_del(head
->prev
);
572 spin_unlock(&bitmap
->write_lock
);
576 static void drain_write_queues(struct bitmap
*bitmap
)
578 struct page_list
*item
;
580 while ((item
= dequeue_page(bitmap
))) {
581 /* don't bother to wait */
582 page_cache_release(item
->page
);
583 mempool_free(item
, bitmap
->write_pool
);
586 wake_up(&bitmap
->write_wait
);
589 static void bitmap_file_put(struct bitmap
*bitmap
)
595 spin_lock_irqsave(&bitmap
->lock
, flags
);
598 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
600 bitmap_stop_daemons(bitmap
);
602 drain_write_queues(bitmap
);
604 bitmap_file_unmap(bitmap
);
607 inode
= file
->f_mapping
->host
;
608 spin_lock(&inode
->i_lock
);
609 atomic_set(&inode
->i_writecount
, 1); /* allow writes again */
610 spin_unlock(&inode
->i_lock
);
617 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
618 * then it is no longer reliable, so we stop using it and we mark the file
619 * as failed in the superblock
621 static void bitmap_file_kick(struct bitmap
*bitmap
)
623 char *path
, *ptr
= NULL
;
625 bitmap_mask_state(bitmap
, BITMAP_STALE
, MASK_SET
);
626 bitmap_update_sb(bitmap
);
628 path
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
630 ptr
= file_path(bitmap
->file
, path
, PAGE_SIZE
);
632 printk(KERN_ALERT
"%s: kicking failed bitmap file %s from array!\n",
633 bmname(bitmap
), ptr
? ptr
: "");
637 bitmap_file_put(bitmap
);
642 enum bitmap_page_attr
{
643 BITMAP_PAGE_DIRTY
= 1, // there are set bits that need to be synced
644 BITMAP_PAGE_CLEAN
= 2, // there are bits that might need to be cleared
645 BITMAP_PAGE_NEEDWRITE
=4, // there are cleared bits that need to be synced
648 static inline void set_page_attr(struct bitmap
*bitmap
, struct page
*page
,
649 enum bitmap_page_attr attr
)
651 bitmap
->filemap_attr
[page
->index
] |= attr
;
654 static inline void clear_page_attr(struct bitmap
*bitmap
, struct page
*page
,
655 enum bitmap_page_attr attr
)
657 bitmap
->filemap_attr
[page
->index
] &= ~attr
;
660 static inline unsigned long get_page_attr(struct bitmap
*bitmap
, struct page
*page
)
662 return bitmap
->filemap_attr
[page
->index
];
666 * bitmap_file_set_bit -- called before performing a write to the md device
667 * to set (and eventually sync) a particular bit in the bitmap file
669 * we set the bit immediately, then we record the page number so that
670 * when an unplug occurs, we can flush the dirty pages out to disk
672 static void bitmap_file_set_bit(struct bitmap
*bitmap
, sector_t block
)
677 unsigned long chunk
= block
>> CHUNK_BLOCK_SHIFT(bitmap
);
679 if (!bitmap
->file
|| !bitmap
->filemap
) {
683 page
= filemap_get_page(bitmap
, chunk
);
684 bit
= file_page_offset(chunk
);
687 /* make sure the page stays cached until it gets written out */
688 if (! (get_page_attr(bitmap
, page
) & BITMAP_PAGE_DIRTY
))
689 page_cache_get(page
);
692 kaddr
= kmap_atomic(page
, KM_USER0
);
694 kunmap_atomic(kaddr
, KM_USER0
);
695 PRINTK("set file bit %lu page %lu\n", bit
, page
->index
);
697 /* record page number so it gets flushed to disk when unplug occurs */
698 set_page_attr(bitmap
, page
, BITMAP_PAGE_DIRTY
);
702 /* this gets called when the md device is ready to unplug its underlying
703 * (slave) device queues -- before we let any writes go down, we need to
704 * sync the dirty pages of the bitmap file to disk */
705 int bitmap_unplug(struct bitmap
*bitmap
)
707 unsigned long i
, attr
, flags
;
714 /* look at each page to see if there are any set bits that need to be
715 * flushed out to disk */
716 for (i
= 0; i
< bitmap
->file_pages
; i
++) {
717 spin_lock_irqsave(&bitmap
->lock
, flags
);
718 if (!bitmap
->file
|| !bitmap
->filemap
) {
719 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
722 page
= bitmap
->filemap
[i
];
723 attr
= get_page_attr(bitmap
, page
);
724 clear_page_attr(bitmap
, page
, BITMAP_PAGE_DIRTY
);
725 clear_page_attr(bitmap
, page
, BITMAP_PAGE_NEEDWRITE
);
726 if ((attr
& BITMAP_PAGE_DIRTY
))
728 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
730 if (attr
& (BITMAP_PAGE_DIRTY
| BITMAP_PAGE_NEEDWRITE
))
731 if (write_page(bitmap
, page
, 0))
734 if (wait
) { /* if any writes were performed, we need to wait on them */
735 spin_lock_irq(&bitmap
->write_lock
);
736 wait_event_lock_irq(bitmap
->write_wait
,
737 list_empty(&bitmap
->complete_pages
), bitmap
->write_lock
,
738 wake_up_process(bitmap
->writeback_daemon
->tsk
));
739 spin_unlock_irq(&bitmap
->write_lock
);
744 static void bitmap_set_memory_bits(struct bitmap
*bitmap
, sector_t offset
,
745 unsigned long sectors
, int in_sync
);
746 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
747 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
748 * memory mapping of the bitmap file
750 * if there's no bitmap file, or if the bitmap file had been
751 * previously kicked from the array, we mark all the bits as
752 * 1's in order to cause a full resync.
754 static int bitmap_init_from_disk(struct bitmap
*bitmap
, int in_sync
)
756 unsigned long i
, chunks
, index
, oldindex
, bit
;
757 struct page
*page
= NULL
, *oldpage
= NULL
;
758 unsigned long num_pages
, bit_cnt
= 0;
760 unsigned long bytes
, offset
, dummy
;
764 chunks
= bitmap
->chunks
;
772 outofdate
= bitmap
->flags
& BITMAP_STALE
;
775 printk(KERN_INFO
"%s: bitmap file is out of date, doing full "
776 "recovery\n", bmname(bitmap
));
778 bytes
= (chunks
+ 7) / 8;
780 num_pages
= (bytes
+ sizeof(bitmap_super_t
) + PAGE_SIZE
- 1) / PAGE_SIZE
;
782 if (i_size_read(file
->f_mapping
->host
) < bytes
+ sizeof(bitmap_super_t
)) {
783 printk(KERN_INFO
"%s: bitmap file too short %lu < %lu\n",
785 (unsigned long) i_size_read(file
->f_mapping
->host
),
786 bytes
+ sizeof(bitmap_super_t
));
792 bitmap
->filemap
= kmalloc(sizeof(struct page
*) * num_pages
, GFP_KERNEL
);
793 if (!bitmap
->filemap
)
796 bitmap
->filemap_attr
= kmalloc(sizeof(long) * num_pages
, GFP_KERNEL
);
797 if (!bitmap
->filemap_attr
)
800 memset(bitmap
->filemap_attr
, 0, sizeof(long) * num_pages
);
804 for (i
= 0; i
< chunks
; i
++) {
805 index
= file_page_index(i
);
806 bit
= file_page_offset(i
);
807 if (index
!= oldindex
) { /* this is a new page, read it in */
808 /* unmap the old page, we're done with it */
813 * if we're here then the superblock page
814 * contains some bits (PAGE_SIZE != sizeof sb)
815 * we've already read it in, so just use it
817 page
= bitmap
->sb_page
;
818 offset
= sizeof(bitmap_super_t
);
820 page
= read_page(file
, index
, &dummy
);
821 if (IS_ERR(page
)) { /* read error */
833 * if bitmap is out of date, dirty the
834 * whole page and write it out
836 memset(page_address(page
) + offset
, 0xff,
838 ret
= write_page(bitmap
, page
, 1);
841 /* release, page not in filemap yet */
842 page_cache_release(page
);
847 bitmap
->filemap
[bitmap
->file_pages
++] = page
;
849 if (test_bit(bit
, page_address(page
))) {
850 /* if the disk bit is set, set the memory bit */
851 bitmap_set_memory_bits(bitmap
,
852 i
<< CHUNK_BLOCK_SHIFT(bitmap
), 1, in_sync
);
857 /* everything went OK */
859 bitmap_mask_state(bitmap
, BITMAP_STALE
, MASK_UNSET
);
861 if (page
) /* unmap the last page */
864 if (bit_cnt
) { /* Kick recovery if any bits were set */
865 set_bit(MD_RECOVERY_NEEDED
, &bitmap
->mddev
->recovery
);
866 md_wakeup_thread(bitmap
->mddev
->thread
);
870 printk(KERN_INFO
"%s: bitmap initialized from disk: "
871 "read %lu/%lu pages, set %lu bits, status: %d\n",
872 bmname(bitmap
), bitmap
->file_pages
, num_pages
, bit_cnt
, ret
);
878 static void bitmap_count_page(struct bitmap
*bitmap
, sector_t offset
, int inc
)
880 sector_t chunk
= offset
>> CHUNK_BLOCK_SHIFT(bitmap
);
881 unsigned long page
= chunk
>> PAGE_COUNTER_SHIFT
;
882 bitmap
->bp
[page
].count
+= inc
;
884 if (page == 0) printk("count page 0, offset %llu: %d gives %d\n",
885 (unsigned long long)offset, inc, bitmap->bp[page].count);
887 bitmap_checkfree(bitmap
, page
);
889 static bitmap_counter_t
*bitmap_get_counter(struct bitmap
*bitmap
,
890 sector_t offset
, int *blocks
,
894 * bitmap daemon -- periodically wakes up to clean bits and flush pages
898 int bitmap_daemon_work(struct bitmap
*bitmap
)
902 struct page
*page
= NULL
, *lastpage
= NULL
;
909 if (time_before(jiffies
, bitmap
->daemon_lastrun
+ bitmap
->daemon_sleep
*HZ
))
911 bitmap
->daemon_lastrun
= jiffies
;
913 for (j
= 0; j
< bitmap
->chunks
; j
++) {
914 bitmap_counter_t
*bmc
;
915 spin_lock_irqsave(&bitmap
->lock
, flags
);
916 if (!bitmap
->file
|| !bitmap
->filemap
) {
917 /* error or shutdown */
918 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
922 page
= filemap_get_page(bitmap
, j
);
924 if (page
!= lastpage
) {
925 /* skip this page unless it's marked as needing cleaning */
926 if (!((attr
=get_page_attr(bitmap
, page
)) & BITMAP_PAGE_CLEAN
)) {
927 if (attr
& BITMAP_PAGE_NEEDWRITE
) {
928 page_cache_get(page
);
929 clear_page_attr(bitmap
, page
, BITMAP_PAGE_NEEDWRITE
);
931 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
932 if (attr
& BITMAP_PAGE_NEEDWRITE
) {
933 if (write_page(bitmap
, page
, 0))
934 bitmap_file_kick(bitmap
);
935 page_cache_release(page
);
940 /* grab the new page, sync and release the old */
941 page_cache_get(page
);
942 if (lastpage
!= NULL
) {
943 if (get_page_attr(bitmap
, lastpage
) & BITMAP_PAGE_NEEDWRITE
) {
944 clear_page_attr(bitmap
, lastpage
, BITMAP_PAGE_NEEDWRITE
);
945 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
946 err
= write_page(bitmap
, lastpage
, 0);
948 set_page_attr(bitmap
, lastpage
, BITMAP_PAGE_NEEDWRITE
);
949 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
952 page_cache_release(lastpage
);
954 bitmap_file_kick(bitmap
);
956 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
960 printk("bitmap clean at page %lu\n", j);
962 spin_lock_irqsave(&bitmap
->lock
, flags
);
963 clear_page_attr(bitmap
, page
, BITMAP_PAGE_CLEAN
);
965 bmc
= bitmap_get_counter(bitmap
, j
<< CHUNK_BLOCK_SHIFT(bitmap
),
969 if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc);
972 *bmc
=1; /* maybe clear the bit next time */
973 set_page_attr(bitmap
, page
, BITMAP_PAGE_CLEAN
);
974 } else if (*bmc
== 1) {
975 /* we can clear the bit */
977 bitmap_count_page(bitmap
, j
<< CHUNK_BLOCK_SHIFT(bitmap
),
981 clear_bit(file_page_offset(j
), page_address(page
));
984 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
987 /* now sync the final page */
988 if (lastpage
!= NULL
) {
990 spin_lock_irqsave(&bitmap
->lock
, flags
);
991 if (get_page_attr(bitmap
, lastpage
) &BITMAP_PAGE_NEEDWRITE
) {
992 clear_page_attr(bitmap
, lastpage
, BITMAP_PAGE_NEEDWRITE
);
993 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
994 err
= write_page(bitmap
, lastpage
, 0);
996 set_page_attr(bitmap
, lastpage
, BITMAP_PAGE_NEEDWRITE
);
997 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1000 page_cache_release(lastpage
);
1006 static void daemon_exit(struct bitmap
*bitmap
, mdk_thread_t
**daemon
)
1009 unsigned long flags
;
1011 /* if no one is waiting on us, we'll free the md thread struct
1012 * and exit, otherwise we let the waiter clean things up */
1013 spin_lock_irqsave(&bitmap
->lock
, flags
);
1014 if ((dmn
= *daemon
)) { /* no one is waiting, cleanup and exit */
1016 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1018 complete_and_exit(NULL
, 0); /* do_exit not exported */
1020 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1023 static void bitmap_writeback_daemon(mddev_t
*mddev
)
1025 struct bitmap
*bitmap
= mddev
->bitmap
;
1027 struct page_list
*item
;
1030 if (signal_pending(current
)) {
1032 "%s: bitmap writeback daemon got signal, exiting...\n",
1038 PRINTK("%s: bitmap writeback daemon woke up...\n", bmname(bitmap
));
1039 /* wait on bitmap page writebacks */
1040 while ((item
= dequeue_page(bitmap
))) {
1042 mempool_free(item
, bitmap
->write_pool
);
1043 PRINTK("wait on page writeback: %p\n", page
);
1044 wait_on_page_writeback(page
);
1045 PRINTK("finished page writeback: %p\n", page
);
1047 err
= PageError(page
);
1048 page_cache_release(page
);
1050 printk(KERN_WARNING
"%s: bitmap file writeback "
1051 "failed (page %lu): %d\n",
1052 bmname(bitmap
), page
->index
, err
);
1053 bitmap_file_kick(bitmap
);
1058 wake_up(&bitmap
->write_wait
);
1060 printk(KERN_INFO
"%s: bitmap writeback daemon exiting (%d)\n",
1061 bmname(bitmap
), err
);
1062 daemon_exit(bitmap
, &bitmap
->writeback_daemon
);
1066 static int bitmap_start_daemon(struct bitmap
*bitmap
, mdk_thread_t
**ptr
,
1067 void (*func
)(mddev_t
*), char *name
)
1069 mdk_thread_t
*daemon
;
1070 unsigned long flags
;
1073 spin_lock_irqsave(&bitmap
->lock
, flags
);
1075 if (!bitmap
->file
) /* no need for daemon if there's no backing file */
1078 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1080 #if INJECT_FATAL_FAULT_2
1083 sprintf(namebuf
, "%%s_%s", name
);
1084 daemon
= md_register_thread(func
, bitmap
->mddev
, namebuf
);
1087 printk(KERN_ERR
"%s: failed to start bitmap daemon\n",
1092 spin_lock_irqsave(&bitmap
->lock
, flags
);
1095 md_wakeup_thread(daemon
); /* start it running */
1097 PRINTK("%s: %s daemon (pid %d) started...\n",
1098 bmname(bitmap
), name
, daemon
->tsk
->pid
);
1100 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1104 static int bitmap_start_daemons(struct bitmap
*bitmap
)
1106 int err
= bitmap_start_daemon(bitmap
, &bitmap
->writeback_daemon
,
1107 bitmap_writeback_daemon
, "bitmap_wb");
1111 static void bitmap_stop_daemon(struct bitmap
*bitmap
, mdk_thread_t
**ptr
)
1113 mdk_thread_t
*daemon
;
1114 unsigned long flags
;
1116 spin_lock_irqsave(&bitmap
->lock
, flags
);
1119 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1121 md_unregister_thread(daemon
); /* destroy the thread */
1124 static void bitmap_stop_daemons(struct bitmap
*bitmap
)
1126 /* the daemons can't stop themselves... they'll just exit instead... */
1127 if (bitmap
->writeback_daemon
&&
1128 current
->pid
!= bitmap
->writeback_daemon
->tsk
->pid
)
1129 bitmap_stop_daemon(bitmap
, &bitmap
->writeback_daemon
);
1132 static bitmap_counter_t
*bitmap_get_counter(struct bitmap
*bitmap
,
1133 sector_t offset
, int *blocks
,
1136 /* If 'create', we might release the lock and reclaim it.
1137 * The lock must have been taken with interrupts enabled.
1138 * If !create, we don't release the lock.
1140 sector_t chunk
= offset
>> CHUNK_BLOCK_SHIFT(bitmap
);
1141 unsigned long page
= chunk
>> PAGE_COUNTER_SHIFT
;
1142 unsigned long pageoff
= (chunk
& PAGE_COUNTER_MASK
) << COUNTER_BYTE_SHIFT
;
1145 if (bitmap_checkpage(bitmap
, page
, create
) < 0) {
1146 csize
= ((sector_t
)1) << (CHUNK_BLOCK_SHIFT(bitmap
));
1147 *blocks
= csize
- (offset
& (csize
- 1));
1150 /* now locked ... */
1152 if (bitmap
->bp
[page
].hijacked
) { /* hijacked pointer */
1153 /* should we use the first or second counter field
1154 * of the hijacked pointer? */
1155 int hi
= (pageoff
> PAGE_COUNTER_MASK
);
1156 csize
= ((sector_t
)1) << (CHUNK_BLOCK_SHIFT(bitmap
) +
1157 PAGE_COUNTER_SHIFT
- 1);
1158 *blocks
= csize
- (offset
& (csize
- 1));
1159 return &((bitmap_counter_t
*)
1160 &bitmap
->bp
[page
].map
)[hi
];
1161 } else { /* page is allocated */
1162 csize
= ((sector_t
)1) << (CHUNK_BLOCK_SHIFT(bitmap
));
1163 *blocks
= csize
- (offset
& (csize
- 1));
1164 return (bitmap_counter_t
*)
1165 &(bitmap
->bp
[page
].map
[pageoff
]);
1169 int bitmap_startwrite(struct bitmap
*bitmap
, sector_t offset
, unsigned long sectors
)
1171 if (!bitmap
) return 0;
1174 bitmap_counter_t
*bmc
;
1176 spin_lock_irq(&bitmap
->lock
);
1177 bmc
= bitmap_get_counter(bitmap
, offset
, &blocks
, 1);
1179 spin_unlock_irq(&bitmap
->lock
);
1185 bitmap_file_set_bit(bitmap
, offset
);
1186 bitmap_count_page(bitmap
,offset
, 1);
1187 blk_plug_device(bitmap
->mddev
->queue
);
1192 if ((*bmc
& COUNTER_MAX
) == COUNTER_MAX
) BUG();
1195 spin_unlock_irq(&bitmap
->lock
);
1198 if (sectors
> blocks
)
1205 void bitmap_endwrite(struct bitmap
*bitmap
, sector_t offset
, unsigned long sectors
,
1208 if (!bitmap
) return;
1211 unsigned long flags
;
1212 bitmap_counter_t
*bmc
;
1214 spin_lock_irqsave(&bitmap
->lock
, flags
);
1215 bmc
= bitmap_get_counter(bitmap
, offset
, &blocks
, 0);
1217 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1221 if (!success
&& ! (*bmc
& NEEDED_MASK
))
1222 *bmc
|= NEEDED_MASK
;
1226 set_page_attr(bitmap
,
1227 filemap_get_page(bitmap
, offset
>> CHUNK_BLOCK_SHIFT(bitmap
)),
1230 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1232 if (sectors
> blocks
)
1238 int bitmap_start_sync(struct bitmap
*bitmap
, sector_t offset
, int *blocks
)
1240 bitmap_counter_t
*bmc
;
1242 if (bitmap
== NULL
) {/* FIXME or bitmap set as 'failed' */
1244 return 1; /* always resync if no bitmap */
1246 spin_lock_irq(&bitmap
->lock
);
1247 bmc
= bitmap_get_counter(bitmap
, offset
, blocks
, 0);
1253 else if (NEEDED(*bmc
)) {
1255 *bmc
|= RESYNC_MASK
;
1256 *bmc
&= ~NEEDED_MASK
;
1259 spin_unlock_irq(&bitmap
->lock
);
1263 void bitmap_end_sync(struct bitmap
*bitmap
, sector_t offset
, int *blocks
, int aborted
)
1265 bitmap_counter_t
*bmc
;
1266 unsigned long flags
;
1268 if (offset == 0) printk("bitmap_end_sync 0 (%d)\n", aborted);
1269 */ if (bitmap
== NULL
) {
1273 spin_lock_irqsave(&bitmap
->lock
, flags
);
1274 bmc
= bitmap_get_counter(bitmap
, offset
, blocks
, 0);
1279 if (offset == 0) printk("bitmap_end sync found 0x%x, blocks %d\n", *bmc, *blocks);
1282 *bmc
&= ~RESYNC_MASK
;
1284 if (!NEEDED(*bmc
) && aborted
)
1285 *bmc
|= NEEDED_MASK
;
1288 set_page_attr(bitmap
,
1289 filemap_get_page(bitmap
, offset
>> CHUNK_BLOCK_SHIFT(bitmap
)),
1295 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1298 void bitmap_close_sync(struct bitmap
*bitmap
)
1300 /* Sync has finished, and any bitmap chunks that weren't synced
1301 * properly have been aborted. It remains to us to clear the
1302 * RESYNC bit wherever it is still on
1304 sector_t sector
= 0;
1306 if (!bitmap
) return;
1307 while (sector
< bitmap
->mddev
->resync_max_sectors
) {
1308 bitmap_end_sync(bitmap
, sector
, &blocks
, 0);
1310 if (sector < 500) printk("bitmap_close_sync: sec %llu blks %d\n",
1311 (unsigned long long)sector, blocks);
1312 */ sector
+= blocks
;
1316 static void bitmap_set_memory_bits(struct bitmap
*bitmap
, sector_t offset
,
1317 unsigned long sectors
, int in_sync
)
1319 /* For each chunk covered by any of these sectors, set the
1320 * counter to 1 and set resync_needed unless in_sync. They should all
1321 * be 0 at this point
1325 bitmap_counter_t
*bmc
;
1326 spin_lock_irq(&bitmap
->lock
);
1327 bmc
= bitmap_get_counter(bitmap
, offset
, &secs
, 1);
1329 spin_unlock_irq(&bitmap
->lock
);
1334 *bmc
= 1 | (in_sync
? 0 : NEEDED_MASK
);
1335 bitmap_count_page(bitmap
, offset
, 1);
1336 page
= filemap_get_page(bitmap
, offset
>> CHUNK_BLOCK_SHIFT(bitmap
));
1337 set_page_attr(bitmap
, page
, BITMAP_PAGE_CLEAN
);
1339 spin_unlock_irq(&bitmap
->lock
);
1347 /* dirty the entire bitmap */
1348 int bitmap_setallbits(struct bitmap
*bitmap
)
1350 unsigned long flags
;
1353 /* dirty the in-memory bitmap */
1354 bitmap_set_memory_bits(bitmap
, 0, bitmap
->chunks
<< CHUNK_BLOCK_SHIFT(bitmap
), 1);
1356 /* dirty the bitmap file */
1357 for (j
= 0; j
< bitmap
->file_pages
; j
++) {
1358 struct page
*page
= bitmap
->filemap
[j
];
1360 spin_lock_irqsave(&bitmap
->lock
, flags
);
1361 page_cache_get(page
);
1362 spin_unlock_irqrestore(&bitmap
->lock
, flags
);
1363 memset(kmap(page
), 0xff, PAGE_SIZE
);
1365 if (write_page(bitmap
, page
, 0))
1373 * free memory that was allocated
1375 void bitmap_destroy(mddev_t
*mddev
)
1377 unsigned long k
, pages
;
1378 struct bitmap_page
*bp
;
1379 struct bitmap
*bitmap
= mddev
->bitmap
;
1381 if (!bitmap
) /* there was no bitmap */
1384 mddev
->bitmap
= NULL
; /* disconnect from the md device */
1386 /* release the bitmap file and kill the daemon */
1387 bitmap_file_put(bitmap
);
1390 pages
= bitmap
->pages
;
1392 /* free all allocated memory */
1394 mempool_destroy(bitmap
->write_pool
);
1396 if (bp
) /* deallocate the page memory */
1397 for (k
= 0; k
< pages
; k
++)
1398 if (bp
[k
].map
&& !bp
[k
].hijacked
)
1405 * initialize the bitmap structure
1406 * if this returns an error, bitmap_destroy must be called to do clean up
1408 int bitmap_create(mddev_t
*mddev
)
1410 struct bitmap
*bitmap
;
1411 unsigned long blocks
= mddev
->resync_max_sectors
;
1412 unsigned long chunks
;
1413 unsigned long pages
;
1414 struct file
*file
= mddev
->bitmap_file
;
1417 BUG_ON(sizeof(bitmap_super_t
) != 256);
1419 if (!file
) /* bitmap disabled, nothing to do */
1422 bitmap
= kmalloc(sizeof(*bitmap
), GFP_KERNEL
);
1426 memset(bitmap
, 0, sizeof(*bitmap
));
1428 spin_lock_init(&bitmap
->lock
);
1429 bitmap
->mddev
= mddev
;
1430 mddev
->bitmap
= bitmap
;
1432 spin_lock_init(&bitmap
->write_lock
);
1433 INIT_LIST_HEAD(&bitmap
->complete_pages
);
1434 init_waitqueue_head(&bitmap
->write_wait
);
1435 bitmap
->write_pool
= mempool_create(WRITE_POOL_SIZE
, write_pool_alloc
,
1436 write_pool_free
, NULL
);
1437 if (!bitmap
->write_pool
)
1440 bitmap
->file
= file
;
1442 /* read superblock from bitmap file (this sets bitmap->chunksize) */
1443 err
= bitmap_read_sb(bitmap
);
1447 bitmap
->chunkshift
= find_first_bit(&bitmap
->chunksize
,
1448 sizeof(bitmap
->chunksize
));
1450 /* now that chunksize and chunkshift are set, we can use these macros */
1451 chunks
= (blocks
+ CHUNK_BLOCK_RATIO(bitmap
) - 1) /
1452 CHUNK_BLOCK_RATIO(bitmap
);
1453 pages
= (chunks
+ PAGE_COUNTER_RATIO
- 1) / PAGE_COUNTER_RATIO
;
1457 bitmap
->chunks
= chunks
;
1458 bitmap
->pages
= pages
;
1459 bitmap
->missing_pages
= pages
;
1460 bitmap
->counter_bits
= COUNTER_BITS
;
1462 bitmap
->syncchunk
= ~0UL;
1464 #if INJECT_FATAL_FAULT_1
1467 bitmap
->bp
= kmalloc(pages
* sizeof(*bitmap
->bp
), GFP_KERNEL
);
1471 memset(bitmap
->bp
, 0, pages
* sizeof(*bitmap
->bp
));
1473 bitmap
->flags
|= BITMAP_ACTIVE
;
1475 /* now that we have some pages available, initialize the in-memory
1476 * bitmap from the on-disk bitmap */
1477 err
= bitmap_init_from_disk(bitmap
, mddev
->recovery_cp
== MaxSector
);
1481 printk(KERN_INFO
"created bitmap (%lu pages) for device %s\n",
1482 pages
, bmname(bitmap
));
1484 /* kick off the bitmap daemons */
1485 err
= bitmap_start_daemons(bitmap
);
1488 return bitmap_update_sb(bitmap
);
1491 /* the bitmap API -- for raid personalities */
1492 EXPORT_SYMBOL(bitmap_startwrite
);
1493 EXPORT_SYMBOL(bitmap_endwrite
);
1494 EXPORT_SYMBOL(bitmap_start_sync
);
1495 EXPORT_SYMBOL(bitmap_end_sync
);
1496 EXPORT_SYMBOL(bitmap_unplug
);
1497 EXPORT_SYMBOL(bitmap_close_sync
);
1498 EXPORT_SYMBOL(bitmap_daemon_work
);
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