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RPC: Do not block on skb allocation
[linux-2.6/verdex.git] / drivers / md / bitmap.c
blob252d55df964296c97960242a016fc7b8573c4279
1 /*
2 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
3 *
4 * bitmap_create - sets up the bitmap structure
5 * bitmap_destroy - destroys the bitmap structure
6 *
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)
11 */
12
13 /*
14 * Still to do:
15 *
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
21 */
22
23 #include <linux/module.h>
24 #include <linux/errno.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/config.h>
28 #include <linux/timer.h>
29 #include <linux/sched.h>
30 #include <linux/list.h>
31 #include <linux/file.h>
32 #include <linux/mount.h>
33 #include <linux/buffer_head.h>
34 #include <linux/raid/md.h>
35 #include <linux/raid/bitmap.h>
36
37 /* debug macros */
38
39 #define DEBUG 0
40
41 #if DEBUG
42 /* these are for debugging purposes only! */
43
44 /* define one and only one of these */
45 #define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */
46 #define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/
47 #define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */
48 #define INJECT_FAULTS_4 0 /* undef */
49 #define INJECT_FAULTS_5 0 /* undef */
50 #define INJECT_FAULTS_6 0
51
52 /* if these are defined, the driver will fail! debug only */
53 #define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */
54 #define INJECT_FATAL_FAULT_2 0 /* undef */
55 #define INJECT_FATAL_FAULT_3 0 /* undef */
56 #endif
57
58 //#define DPRINTK PRINTK /* set this NULL to avoid verbose debug output */
59 #define DPRINTK(x...) do { } while(0)
60
61 #ifndef PRINTK
62 # if DEBUG > 0
63 # define PRINTK(x...) printk(KERN_DEBUG x)
64 # else
65 # define PRINTK(x...)
66 # endif
67 #endif
68
69 static inline char * bmname(struct bitmap *bitmap)
70 {
71 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
72 }
73
74
75 /*
76 * test if the bitmap is active
77 */
78 int bitmap_active(struct bitmap *bitmap)
79 {
80 unsigned long flags;
81 int res = 0;
82
83 if (!bitmap)
84 return res;
85 spin_lock_irqsave(&bitmap->lock, flags);
86 res = bitmap->flags & BITMAP_ACTIVE;
87 spin_unlock_irqrestore(&bitmap->lock, flags);
88 return res;
89 }
90
91 #define WRITE_POOL_SIZE 256
92 /* mempool for queueing pending writes on the bitmap file */
93 static void *write_pool_alloc(gfp_t gfp_flags, void *data)
94 {
95 return kmalloc(sizeof(struct page_list), gfp_flags);
96 }
97
98 static void write_pool_free(void *ptr, void *data)
99 {
100 kfree(ptr);
101 }
102
103 /*
104 * just a placeholder - calls kmalloc for bitmap pages
105 */
106 static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
107 {
108 unsigned char *page;
109
110 #ifdef INJECT_FAULTS_1
111 page = NULL;
112 #else
113 page = kmalloc(PAGE_SIZE, GFP_NOIO);
114 #endif
115 if (!page)
116 printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
117 else
118 PRINTK("%s: bitmap_alloc_page: allocated page at %p\n",
119 bmname(bitmap), page);
120 return page;
121 }
122
123 /*
124 * for now just a placeholder -- just calls kfree for bitmap pages
125 */
126 static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page)
127 {
128 PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page);
129 kfree(page);
130 }
131
132 /*
133 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
134 *
135 * 1) check to see if this page is allocated, if it's not then try to alloc
136 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
137 * page pointer directly as a counter
138 *
139 * if we find our page, we increment the page's refcount so that it stays
140 * allocated while we're using it
141 */
142 static int bitmap_checkpage(struct bitmap *bitmap, unsigned long page, int create)
143 {
144 unsigned char *mappage;
145
146 if (page >= bitmap->pages) {
147 printk(KERN_ALERT
148 "%s: invalid bitmap page request: %lu (> %lu)\n",
149 bmname(bitmap), page, bitmap->pages-1);
150 return -EINVAL;
151 }
152
153
154 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
155 return 0;
156
157 if (bitmap->bp[page].map) /* page is already allocated, just return */
158 return 0;
159
160 if (!create)
161 return -ENOENT;
162
163 spin_unlock_irq(&bitmap->lock);
164
165 /* this page has not been allocated yet */
166
167 if ((mappage = bitmap_alloc_page(bitmap)) == NULL) {
168 PRINTK("%s: bitmap map page allocation failed, hijacking\n",
169 bmname(bitmap));
170 /* failed - set the hijacked flag so that we can use the
171 * pointer as a counter */
172 spin_lock_irq(&bitmap->lock);
173 if (!bitmap->bp[page].map)
174 bitmap->bp[page].hijacked = 1;
175 goto out;
176 }
177
178 /* got a page */
179
180 spin_lock_irq(&bitmap->lock);
181
182 /* recheck the page */
183
184 if (bitmap->bp[page].map || bitmap->bp[page].hijacked) {
185 /* somebody beat us to getting the page */
186 bitmap_free_page(bitmap, mappage);
187 return 0;
188 }
189
190 /* no page was in place and we have one, so install it */
191
192 memset(mappage, 0, PAGE_SIZE);
193 bitmap->bp[page].map = mappage;
194 bitmap->missing_pages--;
195 out:
196 return 0;
197 }
198
199
200 /* if page is completely empty, put it back on the free list, or dealloc it */
201 /* if page was hijacked, unmark the flag so it might get alloced next time */
202 /* Note: lock should be held when calling this */
203 static inline void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
204 {
205 char *ptr;
206
207 if (bitmap->bp[page].count) /* page is still busy */
208 return;
209
210 /* page is no longer in use, it can be released */
211
212 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
213 bitmap->bp[page].hijacked = 0;
214 bitmap->bp[page].map = NULL;
215 return;
216 }
217
218 /* normal case, free the page */
219
220 #if 0
221 /* actually ... let's not. We will probably need the page again exactly when
222 * memory is tight and we are flusing to disk
223 */
224 return;
225 #else
226 ptr = bitmap->bp[page].map;
227 bitmap->bp[page].map = NULL;
228 bitmap->missing_pages++;
229 bitmap_free_page(bitmap, ptr);
230 return;
231 #endif
232 }
233
234
235 /*
236 * bitmap file handling - read and write the bitmap file and its superblock
237 */
238
239 /* copy the pathname of a file to a buffer */
240 char *file_path(struct file *file, char *buf, int count)
241 {
242 struct dentry *d;
243 struct vfsmount *v;
244
245 if (!buf)
246 return NULL;
247
248 d = file->f_dentry;
249 v = file->f_vfsmnt;
250
251 buf = d_path(d, v, buf, count);
252
253 return IS_ERR(buf) ? NULL : buf;
254 }
255
256 /*
257 * basic page I/O operations
258 */
259
260 /* IO operations when bitmap is stored near all superblocks */
261 static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long index)
262 {
263 /* choose a good rdev and read the page from there */
264
265 mdk_rdev_t *rdev;
266 struct list_head *tmp;
267 struct page *page = alloc_page(GFP_KERNEL);
268 sector_t target;
269
270 if (!page)
271 return ERR_PTR(-ENOMEM);
272
273 ITERATE_RDEV(mddev, rdev, tmp) {
274 if (! test_bit(In_sync, &rdev->flags)
275 || test_bit(Faulty, &rdev->flags))
276 continue;
277
278 target = (rdev->sb_offset << 1) + offset + index * (PAGE_SIZE/512);
279
280 if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
281 page->index = index;
282 return page;
283 }
284 }
285 return ERR_PTR(-EIO);
286
287 }
288
289 static int write_sb_page(mddev_t *mddev, long offset, struct page *page, int wait)
290 {
291 mdk_rdev_t *rdev;
292 struct list_head *tmp;
293
294 ITERATE_RDEV(mddev, rdev, tmp)
295 if (test_bit(In_sync, &rdev->flags)
296 && !test_bit(Faulty, &rdev->flags))
297 md_super_write(mddev, rdev,
298 (rdev->sb_offset<<1) + offset
299 + page->index * (PAGE_SIZE/512),
300 PAGE_SIZE,
301 page);
302
303 if (wait)
304 md_super_wait(mddev);
305 return 0;
306 }
307
308 /*
309 * write out a page to a file
310 */
311 static int write_page(struct bitmap *bitmap, struct page *page, int wait)
312 {
313 int ret = -ENOMEM;
314
315 if (bitmap->file == NULL)
316 return write_sb_page(bitmap->mddev, bitmap->offset, page, wait);
317
318 if (wait)
319 lock_page(page);
320 else {
321 if (TestSetPageLocked(page))
322 return -EAGAIN; /* already locked */
323 if (PageWriteback(page)) {
324 unlock_page(page);
325 return -EAGAIN;
326 }
327 }
328
329 ret = page->mapping->a_ops->prepare_write(bitmap->file, page, 0, PAGE_SIZE);
330 if (!ret)
331 ret = page->mapping->a_ops->commit_write(bitmap->file, page, 0,
332 PAGE_SIZE);
333 if (ret) {
334 unlock_page(page);
335 return ret;
336 }
337
338 set_page_dirty(page); /* force it to be written out */
339
340 if (!wait) {
341 /* add to list to be waited for by daemon */
342 struct page_list *item = mempool_alloc(bitmap->write_pool, GFP_NOIO);
343 item->page = page;
344 page_cache_get(page);
345 spin_lock(&bitmap->write_lock);
346 list_add(&item->list, &bitmap->complete_pages);
347 spin_unlock(&bitmap->write_lock);
348 md_wakeup_thread(bitmap->writeback_daemon);
349 }
350 return write_one_page(page, wait);
351 }
352
353 /* read a page from a file, pinning it into cache, and return bytes_read */
354 static struct page *read_page(struct file *file, unsigned long index,
355 unsigned long *bytes_read)
356 {
357 struct inode *inode = file->f_mapping->host;
358 struct page *page = NULL;
359 loff_t isize = i_size_read(inode);
360 unsigned long end_index = isize >> PAGE_CACHE_SHIFT;
361
362 PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_CACHE_SIZE,
363 (unsigned long long)index << PAGE_CACHE_SHIFT);
364
365 page = read_cache_page(inode->i_mapping, index,
366 (filler_t *)inode->i_mapping->a_ops->readpage, file);
367 if (IS_ERR(page))
368 goto out;
369 wait_on_page_locked(page);
370 if (!PageUptodate(page) || PageError(page)) {
371 page_cache_release(page);
372 page = ERR_PTR(-EIO);
373 goto out;
374 }
375
376 if (index > end_index) /* we have read beyond EOF */
377 *bytes_read = 0;
378 else if (index == end_index) /* possible short read */
379 *bytes_read = isize & ~PAGE_CACHE_MASK;
380 else
381 *bytes_read = PAGE_CACHE_SIZE; /* got a full page */
382 out:
383 if (IS_ERR(page))
384 printk(KERN_ALERT "md: bitmap read error: (%dB @ %Lu): %ld\n",
385 (int)PAGE_CACHE_SIZE,
386 (unsigned long long)index << PAGE_CACHE_SHIFT,
387 PTR_ERR(page));
388 return page;
389 }
390
391 /*
392 * bitmap file superblock operations
393 */
394
395 /* update the event counter and sync the superblock to disk */
396 int bitmap_update_sb(struct bitmap *bitmap)
397 {
398 bitmap_super_t *sb;
399 unsigned long flags;
400
401 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
402 return 0;
403 spin_lock_irqsave(&bitmap->lock, flags);
404 if (!bitmap->sb_page) { /* no superblock */
405 spin_unlock_irqrestore(&bitmap->lock, flags);
406 return 0;
407 }
408 spin_unlock_irqrestore(&bitmap->lock, flags);
409 sb = (bitmap_super_t *)kmap(bitmap->sb_page);
410 sb->events = cpu_to_le64(bitmap->mddev->events);
411 if (!bitmap->mddev->degraded)
412 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
413 kunmap(bitmap->sb_page);
414 return write_page(bitmap, bitmap->sb_page, 1);
415 }
416
417 /* print out the bitmap file superblock */
418 void bitmap_print_sb(struct bitmap *bitmap)
419 {
420 bitmap_super_t *sb;
421
422 if (!bitmap || !bitmap->sb_page)
423 return;
424 sb = (bitmap_super_t *)kmap(bitmap->sb_page);
425 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
426 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
427 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
428 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
429 *(__u32 *)(sb->uuid+0),
430 *(__u32 *)(sb->uuid+4),
431 *(__u32 *)(sb->uuid+8),
432 *(__u32 *)(sb->uuid+12));
433 printk(KERN_DEBUG " events: %llu\n",
434 (unsigned long long) le64_to_cpu(sb->events));
435 printk(KERN_DEBUG "events cleared: %llu\n",
436 (unsigned long long) le64_to_cpu(sb->events_cleared));
437 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
438 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
439 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
440 printk(KERN_DEBUG " sync size: %llu KB\n",
441 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
442 printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
443 kunmap(bitmap->sb_page);
444 }
445
446 /* read the superblock from the bitmap file and initialize some bitmap fields */
447 static int bitmap_read_sb(struct bitmap *bitmap)
448 {
449 char *reason = NULL;
450 bitmap_super_t *sb;
451 unsigned long chunksize, daemon_sleep, write_behind;
452 unsigned long bytes_read;
453 unsigned long long events;
454 int err = -EINVAL;
455
456 /* page 0 is the superblock, read it... */
457 if (bitmap->file)
458 bitmap->sb_page = read_page(bitmap->file, 0, &bytes_read);
459 else {
460 bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0);
461 bytes_read = PAGE_SIZE;
462 }
463 if (IS_ERR(bitmap->sb_page)) {
464 err = PTR_ERR(bitmap->sb_page);
465 bitmap->sb_page = NULL;
466 return err;
467 }
468
469 sb = (bitmap_super_t *)kmap(bitmap->sb_page);
470
471 if (bytes_read < sizeof(*sb)) { /* short read */
472 printk(KERN_INFO "%s: bitmap file superblock truncated\n",
473 bmname(bitmap));
474 err = -ENOSPC;
475 goto out;
476 }
477
478 chunksize = le32_to_cpu(sb->chunksize);
479 daemon_sleep = le32_to_cpu(sb->daemon_sleep);
480 write_behind = le32_to_cpu(sb->write_behind);
481
482 /* verify that the bitmap-specific fields are valid */
483 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
484 reason = "bad magic";
485 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
486 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
487 reason = "unrecognized superblock version";
488 else if (chunksize < 512 || chunksize > (1024 * 1024 * 4))
489 reason = "bitmap chunksize out of range (512B - 4MB)";
490 else if ((1 << ffz(~chunksize)) != chunksize)
491 reason = "bitmap chunksize not a power of 2";
492 else if (daemon_sleep < 1 || daemon_sleep > 15)
493 reason = "daemon sleep period out of range (1-15s)";
494 else if (write_behind > COUNTER_MAX)
495 reason = "write-behind limit out of range (0 - 16383)";
496 if (reason) {
497 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
498 bmname(bitmap), reason);
499 goto out;
500 }
501
502 /* keep the array size field of the bitmap superblock up to date */
503 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
504
505 if (!bitmap->mddev->persistent)
506 goto success;
507
508 /*
509 * if we have a persistent array superblock, compare the
510 * bitmap's UUID and event counter to the mddev's
511 */
512 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
513 printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n",
514 bmname(bitmap));
515 goto out;
516 }
517 events = le64_to_cpu(sb->events);
518 if (events < bitmap->mddev->events) {
519 printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) "
520 "-- forcing full recovery\n", bmname(bitmap), events,
521 (unsigned long long) bitmap->mddev->events);
522 sb->state |= BITMAP_STALE;
523 }
524 success:
525 /* assign fields using values from superblock */
526 bitmap->chunksize = chunksize;
527 bitmap->daemon_sleep = daemon_sleep;
528 bitmap->daemon_lastrun = jiffies;
529 bitmap->max_write_behind = write_behind;
530 bitmap->flags |= sb->state;
531 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
532 bitmap->flags |= BITMAP_HOSTENDIAN;
533 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
534 if (sb->state & BITMAP_STALE)
535 bitmap->events_cleared = bitmap->mddev->events;
536 err = 0;
537 out:
538 kunmap(bitmap->sb_page);
539 if (err)
540 bitmap_print_sb(bitmap);
541 return err;
542 }
543
544 enum bitmap_mask_op {
545 MASK_SET,
546 MASK_UNSET
547 };
548
549 /* record the state of the bitmap in the superblock */
550 static void bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
551 enum bitmap_mask_op op)
552 {
553 bitmap_super_t *sb;
554 unsigned long flags;
555
556 spin_lock_irqsave(&bitmap->lock, flags);
557 if (!bitmap || !bitmap->sb_page) { /* can't set the state */
558 spin_unlock_irqrestore(&bitmap->lock, flags);
559 return;
560 }
561 page_cache_get(bitmap->sb_page);
562 spin_unlock_irqrestore(&bitmap->lock, flags);
563 sb = (bitmap_super_t *)kmap(bitmap->sb_page);
564 switch (op) {
565 case MASK_SET: sb->state |= bits;
566 break;
567 case MASK_UNSET: sb->state &= ~bits;
568 break;
569 default: BUG();
570 }
571 kunmap(bitmap->sb_page);
572 page_cache_release(bitmap->sb_page);
573 }
574
575 /*
576 * general bitmap file operations
577 */
578
579 /* calculate the index of the page that contains this bit */
580 static inline unsigned long file_page_index(unsigned long chunk)
581 {
582 return CHUNK_BIT_OFFSET(chunk) >> PAGE_BIT_SHIFT;
583 }
584
585 /* calculate the (bit) offset of this bit within a page */
586 static inline unsigned long file_page_offset(unsigned long chunk)
587 {
588 return CHUNK_BIT_OFFSET(chunk) & (PAGE_BITS - 1);
589 }
590
591 /*
592 * return a pointer to the page in the filemap that contains the given bit
593 *
594 * this lookup is complicated by the fact that the bitmap sb might be exactly
595 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
596 * 0 or page 1
597 */
598 static inline struct page *filemap_get_page(struct bitmap *bitmap,
599 unsigned long chunk)
600 {
601 return bitmap->filemap[file_page_index(chunk) - file_page_index(0)];
602 }
603
604
605 static void bitmap_file_unmap(struct bitmap *bitmap)
606 {
607 struct page **map, *sb_page;
608 unsigned long *attr;
609 int pages;
610 unsigned long flags;
611
612 spin_lock_irqsave(&bitmap->lock, flags);
613 map = bitmap->filemap;
614 bitmap->filemap = NULL;
615 attr = bitmap->filemap_attr;
616 bitmap->filemap_attr = NULL;
617 pages = bitmap->file_pages;
618 bitmap->file_pages = 0;
619 sb_page = bitmap->sb_page;
620 bitmap->sb_page = NULL;
621 spin_unlock_irqrestore(&bitmap->lock, flags);
622
623 while (pages--)
624 if (map[pages]->index != 0) /* 0 is sb_page, release it below */
625 page_cache_release(map[pages]);
626 kfree(map);
627 kfree(attr);
628
629 if (sb_page)
630 page_cache_release(sb_page);
631 }
632
633 static void bitmap_stop_daemon(struct bitmap *bitmap);
634
635 /* dequeue the next item in a page list -- don't call from irq context */
636 static struct page_list *dequeue_page(struct bitmap *bitmap)
637 {
638 struct page_list *item = NULL;
639 struct list_head *head = &bitmap->complete_pages;
640
641 spin_lock(&bitmap->write_lock);
642 if (list_empty(head))
643 goto out;
644 item = list_entry(head->prev, struct page_list, list);
645 list_del(head->prev);
646 out:
647 spin_unlock(&bitmap->write_lock);
648 return item;
649 }
650
651 static void drain_write_queues(struct bitmap *bitmap)
652 {
653 struct page_list *item;
654
655 while ((item = dequeue_page(bitmap))) {
656 /* don't bother to wait */
657 page_cache_release(item->page);
658 mempool_free(item, bitmap->write_pool);
659 }
660
661 wake_up(&bitmap->write_wait);
662 }
663
664 static void bitmap_file_put(struct bitmap *bitmap)
665 {
666 struct file *file;
667 struct inode *inode;
668 unsigned long flags;
669
670 spin_lock_irqsave(&bitmap->lock, flags);
671 file = bitmap->file;
672 bitmap->file = NULL;
673 spin_unlock_irqrestore(&bitmap->lock, flags);
674
675 bitmap_stop_daemon(bitmap);
676
677 drain_write_queues(bitmap);
678
679 bitmap_file_unmap(bitmap);
680
681 if (file) {
682 inode = file->f_mapping->host;
683 spin_lock(&inode->i_lock);
684 atomic_set(&inode->i_writecount, 1); /* allow writes again */
685 spin_unlock(&inode->i_lock);
686 fput(file);
687 }
688 }
689
690
691 /*
692 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
693 * then it is no longer reliable, so we stop using it and we mark the file
694 * as failed in the superblock
695 */
696 static void bitmap_file_kick(struct bitmap *bitmap)
697 {
698 char *path, *ptr = NULL;
699
700 bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET);
701 bitmap_update_sb(bitmap);
702
703 if (bitmap->file) {
704 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
705 if (path)
706 ptr = file_path(bitmap->file, path, PAGE_SIZE);
707
708 printk(KERN_ALERT "%s: kicking failed bitmap file %s from array!\n",
709 bmname(bitmap), ptr ? ptr : "");
710
711 kfree(path);
712 }
713
714 bitmap_file_put(bitmap);
715
716 return;
717 }
718
719 enum bitmap_page_attr {
720 BITMAP_PAGE_DIRTY = 1, // there are set bits that need to be synced
721 BITMAP_PAGE_CLEAN = 2, // there are bits that might need to be cleared
722 BITMAP_PAGE_NEEDWRITE=4, // there are cleared bits that need to be synced
723 };
724
725 static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
726 enum bitmap_page_attr attr)
727 {
728 bitmap->filemap_attr[page->index] |= attr;
729 }
730
731 static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
732 enum bitmap_page_attr attr)
733 {
734 bitmap->filemap_attr[page->index] &= ~attr;
735 }
736
737 static inline unsigned long get_page_attr(struct bitmap *bitmap, struct page *page)
738 {
739 return bitmap->filemap_attr[page->index];
740 }
741
742 /*
743 * bitmap_file_set_bit -- called before performing a write to the md device
744 * to set (and eventually sync) a particular bit in the bitmap file
745 *
746 * we set the bit immediately, then we record the page number so that
747 * when an unplug occurs, we can flush the dirty pages out to disk
748 */
749 static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
750 {
751 unsigned long bit;
752 struct page *page;
753 void *kaddr;
754 unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
755
756 if (!bitmap->filemap) {
757 return;
758 }
759
760 page = filemap_get_page(bitmap, chunk);
761 bit = file_page_offset(chunk);
762
763
764 /* make sure the page stays cached until it gets written out */
765 if (! (get_page_attr(bitmap, page) & BITMAP_PAGE_DIRTY))
766 page_cache_get(page);
767
768 /* set the bit */
769 kaddr = kmap_atomic(page, KM_USER0);
770 if (bitmap->flags & BITMAP_HOSTENDIAN)
771 set_bit(bit, kaddr);
772 else
773 ext2_set_bit(bit, kaddr);
774 kunmap_atomic(kaddr, KM_USER0);
775 PRINTK("set file bit %lu page %lu\n", bit, page->index);
776
777 /* record page number so it gets flushed to disk when unplug occurs */
778 set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
779
780 }
781
782 /* this gets called when the md device is ready to unplug its underlying
783 * (slave) device queues -- before we let any writes go down, we need to
784 * sync the dirty pages of the bitmap file to disk */
785 int bitmap_unplug(struct bitmap *bitmap)
786 {
787 unsigned long i, attr, flags;
788 struct page *page;
789 int wait = 0;
790 int err;
791
792 if (!bitmap)
793 return 0;
794
795 /* look at each page to see if there are any set bits that need to be
796 * flushed out to disk */
797 for (i = 0; i < bitmap->file_pages; i++) {
798 spin_lock_irqsave(&bitmap->lock, flags);
799 if (!bitmap->filemap) {
800 spin_unlock_irqrestore(&bitmap->lock, flags);
801 return 0;
802 }
803 page = bitmap->filemap[i];
804 attr = get_page_attr(bitmap, page);
805 clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
806 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
807 if ((attr & BITMAP_PAGE_DIRTY))
808 wait = 1;
809 spin_unlock_irqrestore(&bitmap->lock, flags);
810
811 if (attr & (BITMAP_PAGE_DIRTY | BITMAP_PAGE_NEEDWRITE)) {
812 err = write_page(bitmap, page, 0);
813 if (err == -EAGAIN) {
814 if (attr & BITMAP_PAGE_DIRTY)
815 err = write_page(bitmap, page, 1);
816 else
817 err = 0;
818 }
819 if (err)
820 return 1;
821 }
822 }
823 if (wait) { /* if any writes were performed, we need to wait on them */
824 if (bitmap->file) {
825 spin_lock_irq(&bitmap->write_lock);
826 wait_event_lock_irq(bitmap->write_wait,
827 list_empty(&bitmap->complete_pages), bitmap->write_lock,
828 wake_up_process(bitmap->writeback_daemon->tsk));
829 spin_unlock_irq(&bitmap->write_lock);
830 } else
831 md_super_wait(bitmap->mddev);
832 }
833 return 0;
834 }
835
836 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
837 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
838 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
839 * memory mapping of the bitmap file
840 * Special cases:
841 * if there's no bitmap file, or if the bitmap file had been
842 * previously kicked from the array, we mark all the bits as
843 * 1's in order to cause a full resync.
844 *
845 * We ignore all bits for sectors that end earlier than 'start'.
846 * This is used when reading an out-of-date bitmap...
847 */
848 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
849 {
850 unsigned long i, chunks, index, oldindex, bit;
851 struct page *page = NULL, *oldpage = NULL;
852 unsigned long num_pages, bit_cnt = 0;
853 struct file *file;
854 unsigned long bytes, offset, dummy;
855 int outofdate;
856 int ret = -ENOSPC;
857
858 chunks = bitmap->chunks;
859 file = bitmap->file;
860
861 BUG_ON(!file && !bitmap->offset);
862
863 #ifdef INJECT_FAULTS_3
864 outofdate = 1;
865 #else
866 outofdate = bitmap->flags & BITMAP_STALE;
867 #endif
868 if (outofdate)
869 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
870 "recovery\n", bmname(bitmap));
871
872 bytes = (chunks + 7) / 8;
873
874 num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE;
875
876 if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
877 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
878 bmname(bitmap),
879 (unsigned long) i_size_read(file->f_mapping->host),
880 bytes + sizeof(bitmap_super_t));
881 goto out;
882 }
883
884 ret = -ENOMEM;
885
886 bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
887 if (!bitmap->filemap)
888 goto out;
889
890 bitmap->filemap_attr = kmalloc(sizeof(long) * num_pages, GFP_KERNEL);
891 if (!bitmap->filemap_attr)
892 goto out;
893
894 memset(bitmap->filemap_attr, 0, sizeof(long) * num_pages);
895
896 oldindex = ~0L;
897
898 for (i = 0; i < chunks; i++) {
899 int b;
900 index = file_page_index(i);
901 bit = file_page_offset(i);
902 if (index != oldindex) { /* this is a new page, read it in */
903 /* unmap the old page, we're done with it */
904 if (oldpage != NULL)
905 kunmap(oldpage);
906 if (index == 0) {
907 /*
908 * if we're here then the superblock page
909 * contains some bits (PAGE_SIZE != sizeof sb)
910 * we've already read it in, so just use it
911 */
912 page = bitmap->sb_page;
913 offset = sizeof(bitmap_super_t);
914 } else if (file) {
915 page = read_page(file, index, &dummy);
916 offset = 0;
917 } else {
918 page = read_sb_page(bitmap->mddev, bitmap->offset, index);
919 offset = 0;
920 }
921 if (IS_ERR(page)) { /* read error */
922 ret = PTR_ERR(page);
923 goto out;
924 }
925
926 oldindex = index;
927 oldpage = page;
928 kmap(page);
929
930 if (outofdate) {
931 /*
932 * if bitmap is out of date, dirty the
933 * whole page and write it out
934 */
935 memset(page_address(page) + offset, 0xff,
936 PAGE_SIZE - offset);
937 ret = write_page(bitmap, page, 1);
938 if (ret) {
939 kunmap(page);
940 /* release, page not in filemap yet */
941 page_cache_release(page);
942 goto out;
943 }
944 }
945
946 bitmap->filemap[bitmap->file_pages++] = page;
947 }
948 if (bitmap->flags & BITMAP_HOSTENDIAN)
949 b = test_bit(bit, page_address(page));
950 else
951 b = ext2_test_bit(bit, page_address(page));
952 if (b) {
953 /* if the disk bit is set, set the memory bit */
954 bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap),
955 ((i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) >= start)
956 );
957 bit_cnt++;
958 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
959 }
960 }
961
962 /* everything went OK */
963 ret = 0;
964 bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
965
966 if (page) /* unmap the last page */
967 kunmap(page);
968
969 if (bit_cnt) { /* Kick recovery if any bits were set */
970 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
971 md_wakeup_thread(bitmap->mddev->thread);
972 }
973
974 out:
975 printk(KERN_INFO "%s: bitmap initialized from disk: "
976 "read %lu/%lu pages, set %lu bits, status: %d\n",
977 bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, ret);
978
979 return ret;
980 }
981
982 void bitmap_write_all(struct bitmap *bitmap)
983 {
984 /* We don't actually write all bitmap blocks here,
985 * just flag them as needing to be written
986 */
987
988 unsigned long chunks = bitmap->chunks;
989 unsigned long bytes = (chunks+7)/8 + sizeof(bitmap_super_t);
990 unsigned long num_pages = (bytes + PAGE_SIZE-1) / PAGE_SIZE;
991 while (num_pages--)
992 bitmap->filemap_attr[num_pages] |= BITMAP_PAGE_NEEDWRITE;
993 }
994
995
996 static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
997 {
998 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
999 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1000 bitmap->bp[page].count += inc;
1001 /*
1002 if (page == 0) printk("count page 0, offset %llu: %d gives %d\n",
1003 (unsigned long long)offset, inc, bitmap->bp[page].count);
1004 */
1005 bitmap_checkfree(bitmap, page);
1006 }
1007 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1008 sector_t offset, int *blocks,
1009 int create);
1010
1011 /*
1012 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1013 * out to disk
1014 */
1015
1016 int bitmap_daemon_work(struct bitmap *bitmap)
1017 {
1018 unsigned long j;
1019 unsigned long flags;
1020 struct page *page = NULL, *lastpage = NULL;
1021 int err = 0;
1022 int blocks;
1023 int attr;
1024
1025 if (bitmap == NULL)
1026 return 0;
1027 if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ))
1028 return 0;
1029 bitmap->daemon_lastrun = jiffies;
1030
1031 for (j = 0; j < bitmap->chunks; j++) {
1032 bitmap_counter_t *bmc;
1033 spin_lock_irqsave(&bitmap->lock, flags);
1034 if (!bitmap->filemap) {
1035 /* error or shutdown */
1036 spin_unlock_irqrestore(&bitmap->lock, flags);
1037 break;
1038 }
1039
1040 page = filemap_get_page(bitmap, j);
1041
1042 if (page != lastpage) {
1043 /* skip this page unless it's marked as needing cleaning */
1044 if (!((attr=get_page_attr(bitmap, page)) & BITMAP_PAGE_CLEAN)) {
1045 if (attr & BITMAP_PAGE_NEEDWRITE) {
1046 page_cache_get(page);
1047 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1048 }
1049 spin_unlock_irqrestore(&bitmap->lock, flags);
1050 if (attr & BITMAP_PAGE_NEEDWRITE) {
1051 switch (write_page(bitmap, page, 0)) {
1052 case -EAGAIN:
1053 set_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1054 break;
1055 case 0:
1056 break;
1057 default:
1058 bitmap_file_kick(bitmap);
1059 }
1060 page_cache_release(page);
1061 }
1062 continue;
1063 }
1064
1065 /* grab the new page, sync and release the old */
1066 page_cache_get(page);
1067 if (lastpage != NULL) {
1068 if (get_page_attr(bitmap, lastpage) & BITMAP_PAGE_NEEDWRITE) {
1069 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1070 spin_unlock_irqrestore(&bitmap->lock, flags);
1071 err = write_page(bitmap, lastpage, 0);
1072 if (err == -EAGAIN) {
1073 err = 0;
1074 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1075 }
1076 } else {
1077 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1078 spin_unlock_irqrestore(&bitmap->lock, flags);
1079 }
1080 kunmap(lastpage);
1081 page_cache_release(lastpage);
1082 if (err)
1083 bitmap_file_kick(bitmap);
1084 } else
1085 spin_unlock_irqrestore(&bitmap->lock, flags);
1086 lastpage = page;
1087 kmap(page);
1088 /*
1089 printk("bitmap clean at page %lu\n", j);
1090 */
1091 spin_lock_irqsave(&bitmap->lock, flags);
1092 clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1093 }
1094 bmc = bitmap_get_counter(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1095 &blocks, 0);
1096 if (bmc) {
1097 /*
1098 if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc);
1099 */
1100 if (*bmc == 2) {
1101 *bmc=1; /* maybe clear the bit next time */
1102 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1103 } else if (*bmc == 1) {
1104 /* we can clear the bit */
1105 *bmc = 0;
1106 bitmap_count_page(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1107 -1);
1108
1109 /* clear the bit */
1110 if (bitmap->flags & BITMAP_HOSTENDIAN)
1111 clear_bit(file_page_offset(j), page_address(page));
1112 else
1113 ext2_clear_bit(file_page_offset(j), page_address(page));
1114 }
1115 }
1116 spin_unlock_irqrestore(&bitmap->lock, flags);
1117 }
1118
1119 /* now sync the final page */
1120 if (lastpage != NULL) {
1121 kunmap(lastpage);
1122 spin_lock_irqsave(&bitmap->lock, flags);
1123 if (get_page_attr(bitmap, lastpage) &BITMAP_PAGE_NEEDWRITE) {
1124 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1125 spin_unlock_irqrestore(&bitmap->lock, flags);
1126 err = write_page(bitmap, lastpage, 0);
1127 if (err == -EAGAIN) {
1128 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1129 err = 0;
1130 }
1131 } else {
1132 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1133 spin_unlock_irqrestore(&bitmap->lock, flags);
1134 }
1135
1136 page_cache_release(lastpage);
1137 }
1138
1139 return err;
1140 }
1141
1142 static void daemon_exit(struct bitmap *bitmap, mdk_thread_t **daemon)
1143 {
1144 mdk_thread_t *dmn;
1145 unsigned long flags;
1146
1147 /* if no one is waiting on us, we'll free the md thread struct
1148 * and exit, otherwise we let the waiter clean things up */
1149 spin_lock_irqsave(&bitmap->lock, flags);
1150 if ((dmn = *daemon)) { /* no one is waiting, cleanup and exit */
1151 *daemon = NULL;
1152 spin_unlock_irqrestore(&bitmap->lock, flags);
1153 kfree(dmn);
1154 complete_and_exit(NULL, 0); /* do_exit not exported */
1155 }
1156 spin_unlock_irqrestore(&bitmap->lock, flags);
1157 }
1158
1159 static void bitmap_writeback_daemon(mddev_t *mddev)
1160 {
1161 struct bitmap *bitmap = mddev->bitmap;
1162 struct page *page;
1163 struct page_list *item;
1164 int err = 0;
1165
1166 if (signal_pending(current)) {
1167 printk(KERN_INFO
1168 "%s: bitmap writeback daemon got signal, exiting...\n",
1169 bmname(bitmap));
1170 err = -EINTR;
1171 goto out;
1172 }
1173 if (bitmap == NULL)
1174 /* about to be stopped. */
1175 return;
1176
1177 PRINTK("%s: bitmap writeback daemon woke up...\n", bmname(bitmap));
1178 /* wait on bitmap page writebacks */
1179 while ((item = dequeue_page(bitmap))) {
1180 page = item->page;
1181 mempool_free(item, bitmap->write_pool);
1182 PRINTK("wait on page writeback: %p\n", page);
1183 wait_on_page_writeback(page);
1184 PRINTK("finished page writeback: %p\n", page);
1185
1186 err = PageError(page);
1187 page_cache_release(page);
1188 if (err) {
1189 printk(KERN_WARNING "%s: bitmap file writeback "
1190 "failed (page %lu): %d\n",
1191 bmname(bitmap), page->index, err);
1192 bitmap_file_kick(bitmap);
1193 goto out;
1194 }
1195 }
1196 out:
1197 wake_up(&bitmap->write_wait);
1198 if (err) {
1199 printk(KERN_INFO "%s: bitmap writeback daemon exiting (%d)\n",
1200 bmname(bitmap), err);
1201 daemon_exit(bitmap, &bitmap->writeback_daemon);
1202 }
1203 }
1204
1205 static mdk_thread_t *bitmap_start_daemon(struct bitmap *bitmap,
1206 void (*func)(mddev_t *), char *name)
1207 {
1208 mdk_thread_t *daemon;
1209 char namebuf[32];
1210
1211 #ifdef INJECT_FATAL_FAULT_2
1212 daemon = NULL;
1213 #else
1214 sprintf(namebuf, "%%s_%s", name);
1215 daemon = md_register_thread(func, bitmap->mddev, namebuf);
1216 #endif
1217 if (!daemon) {
1218 printk(KERN_ERR "%s: failed to start bitmap daemon\n",
1219 bmname(bitmap));
1220 return ERR_PTR(-ECHILD);
1221 }
1222
1223 md_wakeup_thread(daemon); /* start it running */
1224
1225 PRINTK("%s: %s daemon (pid %d) started...\n",
1226 bmname(bitmap), name, daemon->tsk->pid);
1227
1228 return daemon;
1229 }
1230
1231 static void bitmap_stop_daemon(struct bitmap *bitmap)
1232 {
1233 /* the daemon can't stop itself... it'll just exit instead... */
1234 if (bitmap->writeback_daemon && ! IS_ERR(bitmap->writeback_daemon) &&
1235 current->pid != bitmap->writeback_daemon->tsk->pid) {
1236 mdk_thread_t *daemon;
1237 unsigned long flags;
1238
1239 spin_lock_irqsave(&bitmap->lock, flags);
1240 daemon = bitmap->writeback_daemon;
1241 bitmap->writeback_daemon = NULL;
1242 spin_unlock_irqrestore(&bitmap->lock, flags);
1243 if (daemon && ! IS_ERR(daemon))
1244 md_unregister_thread(daemon); /* destroy the thread */
1245 }
1246 }
1247
1248 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1249 sector_t offset, int *blocks,
1250 int create)
1251 {
1252 /* If 'create', we might release the lock and reclaim it.
1253 * The lock must have been taken with interrupts enabled.
1254 * If !create, we don't release the lock.
1255 */
1256 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1257 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1258 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1259 sector_t csize;
1260
1261 if (bitmap_checkpage(bitmap, page, create) < 0) {
1262 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1263 *blocks = csize - (offset & (csize- 1));
1264 return NULL;
1265 }
1266 /* now locked ... */
1267
1268 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1269 /* should we use the first or second counter field
1270 * of the hijacked pointer? */
1271 int hi = (pageoff > PAGE_COUNTER_MASK);
1272 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) +
1273 PAGE_COUNTER_SHIFT - 1);
1274 *blocks = csize - (offset & (csize- 1));
1275 return &((bitmap_counter_t *)
1276 &bitmap->bp[page].map)[hi];
1277 } else { /* page is allocated */
1278 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1279 *blocks = csize - (offset & (csize- 1));
1280 return (bitmap_counter_t *)
1281 &(bitmap->bp[page].map[pageoff]);
1282 }
1283 }
1284
1285 int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1286 {
1287 if (!bitmap) return 0;
1288
1289 if (behind) {
1290 atomic_inc(&bitmap->behind_writes);
1291 PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n",
1292 atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
1293 }
1294
1295 while (sectors) {
1296 int blocks;
1297 bitmap_counter_t *bmc;
1298
1299 spin_lock_irq(&bitmap->lock);
1300 bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
1301 if (!bmc) {
1302 spin_unlock_irq(&bitmap->lock);
1303 return 0;
1304 }
1305
1306 switch(*bmc) {
1307 case 0:
1308 bitmap_file_set_bit(bitmap, offset);
1309 bitmap_count_page(bitmap,offset, 1);
1310 blk_plug_device(bitmap->mddev->queue);
1311 /* fall through */
1312 case 1:
1313 *bmc = 2;
1314 }
1315 if ((*bmc & COUNTER_MAX) == COUNTER_MAX) BUG();
1316 (*bmc)++;
1317
1318 spin_unlock_irq(&bitmap->lock);
1319
1320 offset += blocks;
1321 if (sectors > blocks)
1322 sectors -= blocks;
1323 else sectors = 0;
1324 }
1325 return 0;
1326 }
1327
1328 void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1329 int success, int behind)
1330 {
1331 if (!bitmap) return;
1332 if (behind) {
1333 atomic_dec(&bitmap->behind_writes);
1334 PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n",
1335 atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
1336 }
1337
1338 while (sectors) {
1339 int blocks;
1340 unsigned long flags;
1341 bitmap_counter_t *bmc;
1342
1343 spin_lock_irqsave(&bitmap->lock, flags);
1344 bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
1345 if (!bmc) {
1346 spin_unlock_irqrestore(&bitmap->lock, flags);
1347 return;
1348 }
1349
1350 if (!success && ! (*bmc & NEEDED_MASK))
1351 *bmc |= NEEDED_MASK;
1352
1353 (*bmc)--;
1354 if (*bmc <= 2) {
1355 set_page_attr(bitmap,
1356 filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1357 BITMAP_PAGE_CLEAN);
1358 }
1359 spin_unlock_irqrestore(&bitmap->lock, flags);
1360 offset += blocks;
1361 if (sectors > blocks)
1362 sectors -= blocks;
1363 else sectors = 0;
1364 }
1365 }
1366
1367 int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks,
1368 int degraded)
1369 {
1370 bitmap_counter_t *bmc;
1371 int rv;
1372 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1373 *blocks = 1024;
1374 return 1; /* always resync if no bitmap */
1375 }
1376 spin_lock_irq(&bitmap->lock);
1377 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1378 rv = 0;
1379 if (bmc) {
1380 /* locked */
1381 if (RESYNC(*bmc))
1382 rv = 1;
1383 else if (NEEDED(*bmc)) {
1384 rv = 1;
1385 if (!degraded) { /* don't set/clear bits if degraded */
1386 *bmc |= RESYNC_MASK;
1387 *bmc &= ~NEEDED_MASK;
1388 }
1389 }
1390 }
1391 spin_unlock_irq(&bitmap->lock);
1392 return rv;
1393 }
1394
1395 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted)
1396 {
1397 bitmap_counter_t *bmc;
1398 unsigned long flags;
1399 /*
1400 if (offset == 0) printk("bitmap_end_sync 0 (%d)\n", aborted);
1401 */ if (bitmap == NULL) {
1402 *blocks = 1024;
1403 return;
1404 }
1405 spin_lock_irqsave(&bitmap->lock, flags);
1406 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1407 if (bmc == NULL)
1408 goto unlock;
1409 /* locked */
1410 /*
1411 if (offset == 0) printk("bitmap_end sync found 0x%x, blocks %d\n", *bmc, *blocks);
1412 */
1413 if (RESYNC(*bmc)) {
1414 *bmc &= ~RESYNC_MASK;
1415
1416 if (!NEEDED(*bmc) && aborted)
1417 *bmc |= NEEDED_MASK;
1418 else {
1419 if (*bmc <= 2) {
1420 set_page_attr(bitmap,
1421 filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1422 BITMAP_PAGE_CLEAN);
1423 }
1424 }
1425 }
1426 unlock:
1427 spin_unlock_irqrestore(&bitmap->lock, flags);
1428 }
1429
1430 void bitmap_close_sync(struct bitmap *bitmap)
1431 {
1432 /* Sync has finished, and any bitmap chunks that weren't synced
1433 * properly have been aborted. It remains to us to clear the
1434 * RESYNC bit wherever it is still on
1435 */
1436 sector_t sector = 0;
1437 int blocks;
1438 if (!bitmap) return;
1439 while (sector < bitmap->mddev->resync_max_sectors) {
1440 bitmap_end_sync(bitmap, sector, &blocks, 0);
1441 /*
1442 if (sector < 500) printk("bitmap_close_sync: sec %llu blks %d\n",
1443 (unsigned long long)sector, blocks);
1444 */ sector += blocks;
1445 }
1446 }
1447
1448 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1449 {
1450 /* For each chunk covered by any of these sectors, set the
1451 * counter to 1 and set resync_needed. They should all
1452 * be 0 at this point
1453 */
1454
1455 int secs;
1456 bitmap_counter_t *bmc;
1457 spin_lock_irq(&bitmap->lock);
1458 bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
1459 if (!bmc) {
1460 spin_unlock_irq(&bitmap->lock);
1461 return;
1462 }
1463 if (! *bmc) {
1464 struct page *page;
1465 *bmc = 1 | (needed?NEEDED_MASK:0);
1466 bitmap_count_page(bitmap, offset, 1);
1467 page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
1468 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1469 }
1470 spin_unlock_irq(&bitmap->lock);
1471
1472 }
1473
1474 /*
1475 * flush out any pending updates
1476 */
1477 void bitmap_flush(mddev_t *mddev)
1478 {
1479 struct bitmap *bitmap = mddev->bitmap;
1480 int sleep;
1481
1482 if (!bitmap) /* there was no bitmap */
1483 return;
1484
1485 /* run the daemon_work three time to ensure everything is flushed
1486 * that can be
1487 */
1488 sleep = bitmap->daemon_sleep;
1489 bitmap->daemon_sleep = 0;
1490 bitmap_daemon_work(bitmap);
1491 bitmap_daemon_work(bitmap);
1492 bitmap_daemon_work(bitmap);
1493 bitmap->daemon_sleep = sleep;
1494 bitmap_update_sb(bitmap);
1495 }
1496
1497 /*
1498 * free memory that was allocated
1499 */
1500 static void bitmap_free(struct bitmap *bitmap)
1501 {
1502 unsigned long k, pages;
1503 struct bitmap_page *bp;
1504
1505 if (!bitmap) /* there was no bitmap */
1506 return;
1507
1508 /* release the bitmap file and kill the daemon */
1509 bitmap_file_put(bitmap);
1510
1511 bp = bitmap->bp;
1512 pages = bitmap->pages;
1513
1514 /* free all allocated memory */
1515
1516 mempool_destroy(bitmap->write_pool);
1517
1518 if (bp) /* deallocate the page memory */
1519 for (k = 0; k < pages; k++)
1520 if (bp[k].map && !bp[k].hijacked)
1521 kfree(bp[k].map);
1522 kfree(bp);
1523 kfree(bitmap);
1524 }
1525 void bitmap_destroy(mddev_t *mddev)
1526 {
1527 struct bitmap *bitmap = mddev->bitmap;
1528
1529 if (!bitmap) /* there was no bitmap */
1530 return;
1531
1532 mddev->bitmap = NULL; /* disconnect from the md device */
1533
1534 bitmap_free(bitmap);
1535 }
1536
1537 /*
1538 * initialize the bitmap structure
1539 * if this returns an error, bitmap_destroy must be called to do clean up
1540 */
1541 int bitmap_create(mddev_t *mddev)
1542 {
1543 struct bitmap *bitmap;
1544 unsigned long blocks = mddev->resync_max_sectors;
1545 unsigned long chunks;
1546 unsigned long pages;
1547 struct file *file = mddev->bitmap_file;
1548 int err;
1549 sector_t start;
1550
1551 BUG_ON(sizeof(bitmap_super_t) != 256);
1552
1553 if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */
1554 return 0;
1555
1556 BUG_ON(file && mddev->bitmap_offset);
1557
1558 bitmap = kmalloc(sizeof(*bitmap), GFP_KERNEL);
1559 if (!bitmap)
1560 return -ENOMEM;
1561
1562 memset(bitmap, 0, sizeof(*bitmap));
1563
1564 spin_lock_init(&bitmap->lock);
1565 bitmap->mddev = mddev;
1566
1567 spin_lock_init(&bitmap->write_lock);
1568 INIT_LIST_HEAD(&bitmap->complete_pages);
1569 init_waitqueue_head(&bitmap->write_wait);
1570 bitmap->write_pool = mempool_create(WRITE_POOL_SIZE, write_pool_alloc,
1571 write_pool_free, NULL);
1572 err = -ENOMEM;
1573 if (!bitmap->write_pool)
1574 goto error;
1575
1576 bitmap->file = file;
1577 bitmap->offset = mddev->bitmap_offset;
1578 if (file) get_file(file);
1579 /* read superblock from bitmap file (this sets bitmap->chunksize) */
1580 err = bitmap_read_sb(bitmap);
1581 if (err)
1582 goto error;
1583
1584 bitmap->chunkshift = find_first_bit(&bitmap->chunksize,
1585 sizeof(bitmap->chunksize));
1586
1587 /* now that chunksize and chunkshift are set, we can use these macros */
1588 chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) /
1589 CHUNK_BLOCK_RATIO(bitmap);
1590 pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1591
1592 BUG_ON(!pages);
1593
1594 bitmap->chunks = chunks;
1595 bitmap->pages = pages;
1596 bitmap->missing_pages = pages;
1597 bitmap->counter_bits = COUNTER_BITS;
1598
1599 bitmap->syncchunk = ~0UL;
1600
1601 #ifdef INJECT_FATAL_FAULT_1
1602 bitmap->bp = NULL;
1603 #else
1604 bitmap->bp = kmalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1605 #endif
1606 err = -ENOMEM;
1607 if (!bitmap->bp)
1608 goto error;
1609 memset(bitmap->bp, 0, pages * sizeof(*bitmap->bp));
1610
1611 bitmap->flags |= BITMAP_ACTIVE;
1612
1613 /* now that we have some pages available, initialize the in-memory
1614 * bitmap from the on-disk bitmap */
1615 start = 0;
1616 if (mddev->degraded == 0
1617 || bitmap->events_cleared == mddev->events)
1618 /* no need to keep dirty bits to optimise a re-add of a missing device */
1619 start = mddev->recovery_cp;
1620 err = bitmap_init_from_disk(bitmap, start);
1621
1622 if (err)
1623 goto error;
1624
1625 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1626 pages, bmname(bitmap));
1627
1628 mddev->bitmap = bitmap;
1629
1630 if (file)
1631 /* kick off the bitmap writeback daemon */
1632 bitmap->writeback_daemon =
1633 bitmap_start_daemon(bitmap,
1634 bitmap_writeback_daemon,
1635 "bitmap_wb");
1636
1637 if (IS_ERR(bitmap->writeback_daemon))
1638 return PTR_ERR(bitmap->writeback_daemon);
1639 return bitmap_update_sb(bitmap);
1640
1641 error:
1642 bitmap_free(bitmap);
1643 return err;
1644 }
1645
1646 /* the bitmap API -- for raid personalities */
1647 EXPORT_SYMBOL(bitmap_startwrite);
1648 EXPORT_SYMBOL(bitmap_endwrite);
1649 EXPORT_SYMBOL(bitmap_start_sync);
1650 EXPORT_SYMBOL(bitmap_end_sync);
1651 EXPORT_SYMBOL(bitmap_unplug);
1652 EXPORT_SYMBOL(bitmap_close_sync);
1653 EXPORT_SYMBOL(bitmap_daemon_work);
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