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Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / drivers / md / bitmap.c
blobc14dacdacfac530c61370b14de5686d6b51c02a3
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 */
11
12 /*
13 * Still to do:
14 *
15 * flush after percent set rather than just time based. (maybe both).
16 * wait if count gets too high, wake when it drops to half.
17 */
18
19 #include <linux/module.h>
20 #include <linux/errno.h>
21 #include <linux/slab.h>
22 #include <linux/init.h>
23 #include <linux/timer.h>
24 #include <linux/sched.h>
25 #include <linux/list.h>
26 #include <linux/file.h>
27 #include <linux/mount.h>
28 #include <linux/buffer_head.h>
29 #include <linux/raid/md.h>
30 #include <linux/raid/bitmap.h>
31
32 /* debug macros */
33
34 #define DEBUG 0
35
36 #if DEBUG
37 /* these are for debugging purposes only! */
38
39 /* define one and only one of these */
40 #define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */
41 #define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/
42 #define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */
43 #define INJECT_FAULTS_4 0 /* undef */
44 #define INJECT_FAULTS_5 0 /* undef */
45 #define INJECT_FAULTS_6 0
46
47 /* if these are defined, the driver will fail! debug only */
48 #define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */
49 #define INJECT_FATAL_FAULT_2 0 /* undef */
50 #define INJECT_FATAL_FAULT_3 0 /* undef */
51 #endif
52
53 //#define DPRINTK PRINTK /* set this NULL to avoid verbose debug output */
54 #define DPRINTK(x...) do { } while(0)
55
56 #ifndef PRINTK
57 # if DEBUG > 0
58 # define PRINTK(x...) printk(KERN_DEBUG x)
59 # else
60 # define PRINTK(x...)
61 # endif
62 #endif
63
64 static inline char * bmname(struct bitmap *bitmap)
65 {
66 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
67 }
68
69
70 /*
71 * just a placeholder - calls kmalloc for bitmap pages
72 */
73 static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
74 {
75 unsigned char *page;
76
77 #ifdef INJECT_FAULTS_1
78 page = NULL;
79 #else
80 page = kmalloc(PAGE_SIZE, GFP_NOIO);
81 #endif
82 if (!page)
83 printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
84 else
85 PRINTK("%s: bitmap_alloc_page: allocated page at %p\n",
86 bmname(bitmap), page);
87 return page;
88 }
89
90 /*
91 * for now just a placeholder -- just calls kfree for bitmap pages
92 */
93 static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page)
94 {
95 PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page);
96 kfree(page);
97 }
98
99 /*
100 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
101 *
102 * 1) check to see if this page is allocated, if it's not then try to alloc
103 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
104 * page pointer directly as a counter
105 *
106 * if we find our page, we increment the page's refcount so that it stays
107 * allocated while we're using it
108 */
109 static int bitmap_checkpage(struct bitmap *bitmap, unsigned long page, int create)
110 {
111 unsigned char *mappage;
112
113 if (page >= bitmap->pages) {
114 printk(KERN_ALERT
115 "%s: invalid bitmap page request: %lu (> %lu)\n",
116 bmname(bitmap), page, bitmap->pages-1);
117 return -EINVAL;
118 }
119
120
121 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
122 return 0;
123
124 if (bitmap->bp[page].map) /* page is already allocated, just return */
125 return 0;
126
127 if (!create)
128 return -ENOENT;
129
130 spin_unlock_irq(&bitmap->lock);
131
132 /* this page has not been allocated yet */
133
134 if ((mappage = bitmap_alloc_page(bitmap)) == NULL) {
135 PRINTK("%s: bitmap map page allocation failed, hijacking\n",
136 bmname(bitmap));
137 /* failed - set the hijacked flag so that we can use the
138 * pointer as a counter */
139 spin_lock_irq(&bitmap->lock);
140 if (!bitmap->bp[page].map)
141 bitmap->bp[page].hijacked = 1;
142 goto out;
143 }
144
145 /* got a page */
146
147 spin_lock_irq(&bitmap->lock);
148
149 /* recheck the page */
150
151 if (bitmap->bp[page].map || bitmap->bp[page].hijacked) {
152 /* somebody beat us to getting the page */
153 bitmap_free_page(bitmap, mappage);
154 return 0;
155 }
156
157 /* no page was in place and we have one, so install it */
158
159 memset(mappage, 0, PAGE_SIZE);
160 bitmap->bp[page].map = mappage;
161 bitmap->missing_pages--;
162 out:
163 return 0;
164 }
165
166
167 /* if page is completely empty, put it back on the free list, or dealloc it */
168 /* if page was hijacked, unmark the flag so it might get alloced next time */
169 /* Note: lock should be held when calling this */
170 static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
171 {
172 char *ptr;
173
174 if (bitmap->bp[page].count) /* page is still busy */
175 return;
176
177 /* page is no longer in use, it can be released */
178
179 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
180 bitmap->bp[page].hijacked = 0;
181 bitmap->bp[page].map = NULL;
182 return;
183 }
184
185 /* normal case, free the page */
186
187 #if 0
188 /* actually ... let's not. We will probably need the page again exactly when
189 * memory is tight and we are flusing to disk
190 */
191 return;
192 #else
193 ptr = bitmap->bp[page].map;
194 bitmap->bp[page].map = NULL;
195 bitmap->missing_pages++;
196 bitmap_free_page(bitmap, ptr);
197 return;
198 #endif
199 }
200
201
202 /*
203 * bitmap file handling - read and write the bitmap file and its superblock
204 */
205
206 /* copy the pathname of a file to a buffer */
207 char *file_path(struct file *file, char *buf, int count)
208 {
209 if (!buf)
210 return NULL;
211
212 buf = d_path(&file->f_path, buf, count);
213
214 return IS_ERR(buf) ? NULL : buf;
215 }
216
217 /*
218 * basic page I/O operations
219 */
220
221 /* IO operations when bitmap is stored near all superblocks */
222 static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long index)
223 {
224 /* choose a good rdev and read the page from there */
225
226 mdk_rdev_t *rdev;
227 struct list_head *tmp;
228 struct page *page = alloc_page(GFP_KERNEL);
229 sector_t target;
230
231 if (!page)
232 return ERR_PTR(-ENOMEM);
233
234 rdev_for_each(rdev, tmp, mddev) {
235 if (! test_bit(In_sync, &rdev->flags)
236 || test_bit(Faulty, &rdev->flags))
237 continue;
238
239 target = (rdev->sb_offset << 1) + offset + index * (PAGE_SIZE/512);
240
241 if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
242 page->index = index;
243 attach_page_buffers(page, NULL); /* so that free_buffer will
244 * quietly no-op */
245 return page;
246 }
247 }
248 return ERR_PTR(-EIO);
249
250 }
251
252 static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
253 {
254 mdk_rdev_t *rdev;
255 struct list_head *tmp;
256 mddev_t *mddev = bitmap->mddev;
257
258 rdev_for_each(rdev, tmp, mddev)
259 if (test_bit(In_sync, &rdev->flags)
260 && !test_bit(Faulty, &rdev->flags)) {
261 int size = PAGE_SIZE;
262 if (page->index == bitmap->file_pages-1)
263 size = roundup(bitmap->last_page_size,
264 bdev_hardsect_size(rdev->bdev));
265 /* Just make sure we aren't corrupting data or
266 * metadata
267 */
268 if (bitmap->offset < 0) {
269 /* DATA BITMAP METADATA */
270 if (bitmap->offset
271 + (long)(page->index * (PAGE_SIZE/512))
272 + size/512 > 0)
273 /* bitmap runs in to metadata */
274 return -EINVAL;
275 if (rdev->data_offset + mddev->size*2
276 > rdev->sb_offset*2 + bitmap->offset)
277 /* data runs in to bitmap */
278 return -EINVAL;
279 } else if (rdev->sb_offset*2 < rdev->data_offset) {
280 /* METADATA BITMAP DATA */
281 if (rdev->sb_offset*2
282 + bitmap->offset
283 + page->index*(PAGE_SIZE/512) + size/512
284 > rdev->data_offset)
285 /* bitmap runs in to data */
286 return -EINVAL;
287 } else {
288 /* DATA METADATA BITMAP - no problems */
289 }
290 md_super_write(mddev, rdev,
291 (rdev->sb_offset<<1) + bitmap->offset
292 + page->index * (PAGE_SIZE/512),
293 size,
294 page);
295 }
296
297 if (wait)
298 md_super_wait(mddev);
299 return 0;
300 }
301
302 static void bitmap_file_kick(struct bitmap *bitmap);
303 /*
304 * write out a page to a file
305 */
306 static void write_page(struct bitmap *bitmap, struct page *page, int wait)
307 {
308 struct buffer_head *bh;
309
310 if (bitmap->file == NULL) {
311 switch (write_sb_page(bitmap, page, wait)) {
312 case -EINVAL:
313 bitmap->flags |= BITMAP_WRITE_ERROR;
314 }
315 } else {
316
317 bh = page_buffers(page);
318
319 while (bh && bh->b_blocknr) {
320 atomic_inc(&bitmap->pending_writes);
321 set_buffer_locked(bh);
322 set_buffer_mapped(bh);
323 submit_bh(WRITE, bh);
324 bh = bh->b_this_page;
325 }
326
327 if (wait) {
328 wait_event(bitmap->write_wait,
329 atomic_read(&bitmap->pending_writes)==0);
330 }
331 }
332 if (bitmap->flags & BITMAP_WRITE_ERROR)
333 bitmap_file_kick(bitmap);
334 }
335
336 static void end_bitmap_write(struct buffer_head *bh, int uptodate)
337 {
338 struct bitmap *bitmap = bh->b_private;
339 unsigned long flags;
340
341 if (!uptodate) {
342 spin_lock_irqsave(&bitmap->lock, flags);
343 bitmap->flags |= BITMAP_WRITE_ERROR;
344 spin_unlock_irqrestore(&bitmap->lock, flags);
345 }
346 if (atomic_dec_and_test(&bitmap->pending_writes))
347 wake_up(&bitmap->write_wait);
348 }
349
350 /* copied from buffer.c */
351 static void
352 __clear_page_buffers(struct page *page)
353 {
354 ClearPagePrivate(page);
355 set_page_private(page, 0);
356 page_cache_release(page);
357 }
358 static void free_buffers(struct page *page)
359 {
360 struct buffer_head *bh = page_buffers(page);
361
362 while (bh) {
363 struct buffer_head *next = bh->b_this_page;
364 free_buffer_head(bh);
365 bh = next;
366 }
367 __clear_page_buffers(page);
368 put_page(page);
369 }
370
371 /* read a page from a file.
372 * We both read the page, and attach buffers to the page to record the
373 * address of each block (using bmap). These addresses will be used
374 * to write the block later, completely bypassing the filesystem.
375 * This usage is similar to how swap files are handled, and allows us
376 * to write to a file with no concerns of memory allocation failing.
377 */
378 static struct page *read_page(struct file *file, unsigned long index,
379 struct bitmap *bitmap,
380 unsigned long count)
381 {
382 struct page *page = NULL;
383 struct inode *inode = file->f_path.dentry->d_inode;
384 struct buffer_head *bh;
385 sector_t block;
386
387 PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_SIZE,
388 (unsigned long long)index << PAGE_SHIFT);
389
390 page = alloc_page(GFP_KERNEL);
391 if (!page)
392 page = ERR_PTR(-ENOMEM);
393 if (IS_ERR(page))
394 goto out;
395
396 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
397 if (!bh) {
398 put_page(page);
399 page = ERR_PTR(-ENOMEM);
400 goto out;
401 }
402 attach_page_buffers(page, bh);
403 block = index << (PAGE_SHIFT - inode->i_blkbits);
404 while (bh) {
405 if (count == 0)
406 bh->b_blocknr = 0;
407 else {
408 bh->b_blocknr = bmap(inode, block);
409 if (bh->b_blocknr == 0) {
410 /* Cannot use this file! */
411 free_buffers(page);
412 page = ERR_PTR(-EINVAL);
413 goto out;
414 }
415 bh->b_bdev = inode->i_sb->s_bdev;
416 if (count < (1<<inode->i_blkbits))
417 count = 0;
418 else
419 count -= (1<<inode->i_blkbits);
420
421 bh->b_end_io = end_bitmap_write;
422 bh->b_private = bitmap;
423 atomic_inc(&bitmap->pending_writes);
424 set_buffer_locked(bh);
425 set_buffer_mapped(bh);
426 submit_bh(READ, bh);
427 }
428 block++;
429 bh = bh->b_this_page;
430 }
431 page->index = index;
432
433 wait_event(bitmap->write_wait,
434 atomic_read(&bitmap->pending_writes)==0);
435 if (bitmap->flags & BITMAP_WRITE_ERROR) {
436 free_buffers(page);
437 page = ERR_PTR(-EIO);
438 }
439 out:
440 if (IS_ERR(page))
441 printk(KERN_ALERT "md: bitmap read error: (%dB @ %Lu): %ld\n",
442 (int)PAGE_SIZE,
443 (unsigned long long)index << PAGE_SHIFT,
444 PTR_ERR(page));
445 return page;
446 }
447
448 /*
449 * bitmap file superblock operations
450 */
451
452 /* update the event counter and sync the superblock to disk */
453 void bitmap_update_sb(struct bitmap *bitmap)
454 {
455 bitmap_super_t *sb;
456 unsigned long flags;
457
458 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
459 return;
460 spin_lock_irqsave(&bitmap->lock, flags);
461 if (!bitmap->sb_page) { /* no superblock */
462 spin_unlock_irqrestore(&bitmap->lock, flags);
463 return;
464 }
465 spin_unlock_irqrestore(&bitmap->lock, flags);
466 sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
467 sb->events = cpu_to_le64(bitmap->mddev->events);
468 if (!bitmap->mddev->degraded)
469 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
470 kunmap_atomic(sb, KM_USER0);
471 write_page(bitmap, bitmap->sb_page, 1);
472 }
473
474 /* print out the bitmap file superblock */
475 void bitmap_print_sb(struct bitmap *bitmap)
476 {
477 bitmap_super_t *sb;
478
479 if (!bitmap || !bitmap->sb_page)
480 return;
481 sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
482 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
483 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
484 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
485 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
486 *(__u32 *)(sb->uuid+0),
487 *(__u32 *)(sb->uuid+4),
488 *(__u32 *)(sb->uuid+8),
489 *(__u32 *)(sb->uuid+12));
490 printk(KERN_DEBUG " events: %llu\n",
491 (unsigned long long) le64_to_cpu(sb->events));
492 printk(KERN_DEBUG "events cleared: %llu\n",
493 (unsigned long long) le64_to_cpu(sb->events_cleared));
494 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
495 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
496 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
497 printk(KERN_DEBUG " sync size: %llu KB\n",
498 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
499 printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
500 kunmap_atomic(sb, KM_USER0);
501 }
502
503 /* read the superblock from the bitmap file and initialize some bitmap fields */
504 static int bitmap_read_sb(struct bitmap *bitmap)
505 {
506 char *reason = NULL;
507 bitmap_super_t *sb;
508 unsigned long chunksize, daemon_sleep, write_behind;
509 unsigned long long events;
510 int err = -EINVAL;
511
512 /* page 0 is the superblock, read it... */
513 if (bitmap->file) {
514 loff_t isize = i_size_read(bitmap->file->f_mapping->host);
515 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
516
517 bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
518 } else {
519 bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0);
520 }
521 if (IS_ERR(bitmap->sb_page)) {
522 err = PTR_ERR(bitmap->sb_page);
523 bitmap->sb_page = NULL;
524 return err;
525 }
526
527 sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
528
529 chunksize = le32_to_cpu(sb->chunksize);
530 daemon_sleep = le32_to_cpu(sb->daemon_sleep);
531 write_behind = le32_to_cpu(sb->write_behind);
532
533 /* verify that the bitmap-specific fields are valid */
534 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
535 reason = "bad magic";
536 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
537 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
538 reason = "unrecognized superblock version";
539 else if (chunksize < PAGE_SIZE)
540 reason = "bitmap chunksize too small";
541 else if ((1 << ffz(~chunksize)) != chunksize)
542 reason = "bitmap chunksize not a power of 2";
543 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT / HZ)
544 reason = "daemon sleep period out of range";
545 else if (write_behind > COUNTER_MAX)
546 reason = "write-behind limit out of range (0 - 16383)";
547 if (reason) {
548 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
549 bmname(bitmap), reason);
550 goto out;
551 }
552
553 /* keep the array size field of the bitmap superblock up to date */
554 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
555
556 if (!bitmap->mddev->persistent)
557 goto success;
558
559 /*
560 * if we have a persistent array superblock, compare the
561 * bitmap's UUID and event counter to the mddev's
562 */
563 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
564 printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n",
565 bmname(bitmap));
566 goto out;
567 }
568 events = le64_to_cpu(sb->events);
569 if (events < bitmap->mddev->events) {
570 printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) "
571 "-- forcing full recovery\n", bmname(bitmap), events,
572 (unsigned long long) bitmap->mddev->events);
573 sb->state |= cpu_to_le32(BITMAP_STALE);
574 }
575 success:
576 /* assign fields using values from superblock */
577 bitmap->chunksize = chunksize;
578 bitmap->daemon_sleep = daemon_sleep;
579 bitmap->daemon_lastrun = jiffies;
580 bitmap->max_write_behind = write_behind;
581 bitmap->flags |= le32_to_cpu(sb->state);
582 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
583 bitmap->flags |= BITMAP_HOSTENDIAN;
584 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
585 if (sb->state & cpu_to_le32(BITMAP_STALE))
586 bitmap->events_cleared = bitmap->mddev->events;
587 err = 0;
588 out:
589 kunmap_atomic(sb, KM_USER0);
590 if (err)
591 bitmap_print_sb(bitmap);
592 return err;
593 }
594
595 enum bitmap_mask_op {
596 MASK_SET,
597 MASK_UNSET
598 };
599
600 /* record the state of the bitmap in the superblock. Return the old value */
601 static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
602 enum bitmap_mask_op op)
603 {
604 bitmap_super_t *sb;
605 unsigned long flags;
606 int old;
607
608 spin_lock_irqsave(&bitmap->lock, flags);
609 if (!bitmap->sb_page) { /* can't set the state */
610 spin_unlock_irqrestore(&bitmap->lock, flags);
611 return 0;
612 }
613 spin_unlock_irqrestore(&bitmap->lock, flags);
614 sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
615 old = le32_to_cpu(sb->state) & bits;
616 switch (op) {
617 case MASK_SET: sb->state |= cpu_to_le32(bits);
618 break;
619 case MASK_UNSET: sb->state &= cpu_to_le32(~bits);
620 break;
621 default: BUG();
622 }
623 kunmap_atomic(sb, KM_USER0);
624 return old;
625 }
626
627 /*
628 * general bitmap file operations
629 */
630
631 /* calculate the index of the page that contains this bit */
632 static inline unsigned long file_page_index(unsigned long chunk)
633 {
634 return CHUNK_BIT_OFFSET(chunk) >> PAGE_BIT_SHIFT;
635 }
636
637 /* calculate the (bit) offset of this bit within a page */
638 static inline unsigned long file_page_offset(unsigned long chunk)
639 {
640 return CHUNK_BIT_OFFSET(chunk) & (PAGE_BITS - 1);
641 }
642
643 /*
644 * return a pointer to the page in the filemap that contains the given bit
645 *
646 * this lookup is complicated by the fact that the bitmap sb might be exactly
647 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
648 * 0 or page 1
649 */
650 static inline struct page *filemap_get_page(struct bitmap *bitmap,
651 unsigned long chunk)
652 {
653 if (file_page_index(chunk) >= bitmap->file_pages) return NULL;
654 return bitmap->filemap[file_page_index(chunk) - file_page_index(0)];
655 }
656
657
658 static void bitmap_file_unmap(struct bitmap *bitmap)
659 {
660 struct page **map, *sb_page;
661 unsigned long *attr;
662 int pages;
663 unsigned long flags;
664
665 spin_lock_irqsave(&bitmap->lock, flags);
666 map = bitmap->filemap;
667 bitmap->filemap = NULL;
668 attr = bitmap->filemap_attr;
669 bitmap->filemap_attr = NULL;
670 pages = bitmap->file_pages;
671 bitmap->file_pages = 0;
672 sb_page = bitmap->sb_page;
673 bitmap->sb_page = NULL;
674 spin_unlock_irqrestore(&bitmap->lock, flags);
675
676 while (pages--)
677 if (map[pages]->index != 0) /* 0 is sb_page, release it below */
678 free_buffers(map[pages]);
679 kfree(map);
680 kfree(attr);
681
682 if (sb_page)
683 free_buffers(sb_page);
684 }
685
686 static void bitmap_file_put(struct bitmap *bitmap)
687 {
688 struct file *file;
689 unsigned long flags;
690
691 spin_lock_irqsave(&bitmap->lock, flags);
692 file = bitmap->file;
693 bitmap->file = NULL;
694 spin_unlock_irqrestore(&bitmap->lock, flags);
695
696 if (file)
697 wait_event(bitmap->write_wait,
698 atomic_read(&bitmap->pending_writes)==0);
699 bitmap_file_unmap(bitmap);
700
701 if (file) {
702 struct inode *inode = file->f_path.dentry->d_inode;
703 invalidate_mapping_pages(inode->i_mapping, 0, -1);
704 fput(file);
705 }
706 }
707
708
709 /*
710 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
711 * then it is no longer reliable, so we stop using it and we mark the file
712 * as failed in the superblock
713 */
714 static void bitmap_file_kick(struct bitmap *bitmap)
715 {
716 char *path, *ptr = NULL;
717
718 if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) {
719 bitmap_update_sb(bitmap);
720
721 if (bitmap->file) {
722 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
723 if (path)
724 ptr = file_path(bitmap->file, path, PAGE_SIZE);
725
726 printk(KERN_ALERT
727 "%s: kicking failed bitmap file %s from array!\n",
728 bmname(bitmap), ptr ? ptr : "");
729
730 kfree(path);
731 } else
732 printk(KERN_ALERT
733 "%s: disabling internal bitmap due to errors\n",
734 bmname(bitmap));
735 }
736
737 bitmap_file_put(bitmap);
738
739 return;
740 }
741
742 enum bitmap_page_attr {
743 BITMAP_PAGE_DIRTY = 0, // there are set bits that need to be synced
744 BITMAP_PAGE_CLEAN = 1, // there are bits that might need to be cleared
745 BITMAP_PAGE_NEEDWRITE=2, // there are cleared bits that need to be synced
746 };
747
748 static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
749 enum bitmap_page_attr attr)
750 {
751 __set_bit((page->index<<2) + attr, bitmap->filemap_attr);
752 }
753
754 static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
755 enum bitmap_page_attr attr)
756 {
757 __clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
758 }
759
760 static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
761 enum bitmap_page_attr attr)
762 {
763 return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
764 }
765
766 /*
767 * bitmap_file_set_bit -- called before performing a write to the md device
768 * to set (and eventually sync) a particular bit in the bitmap file
769 *
770 * we set the bit immediately, then we record the page number so that
771 * when an unplug occurs, we can flush the dirty pages out to disk
772 */
773 static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
774 {
775 unsigned long bit;
776 struct page *page;
777 void *kaddr;
778 unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
779
780 if (!bitmap->filemap) {
781 return;
782 }
783
784 page = filemap_get_page(bitmap, chunk);
785 if (!page) return;
786 bit = file_page_offset(chunk);
787
788 /* set the bit */
789 kaddr = kmap_atomic(page, KM_USER0);
790 if (bitmap->flags & BITMAP_HOSTENDIAN)
791 set_bit(bit, kaddr);
792 else
793 ext2_set_bit(bit, kaddr);
794 kunmap_atomic(kaddr, KM_USER0);
795 PRINTK("set file bit %lu page %lu\n", bit, page->index);
796
797 /* record page number so it gets flushed to disk when unplug occurs */
798 set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
799
800 }
801
802 /* this gets called when the md device is ready to unplug its underlying
803 * (slave) device queues -- before we let any writes go down, we need to
804 * sync the dirty pages of the bitmap file to disk */
805 void bitmap_unplug(struct bitmap *bitmap)
806 {
807 unsigned long i, flags;
808 int dirty, need_write;
809 struct page *page;
810 int wait = 0;
811
812 if (!bitmap)
813 return;
814
815 /* look at each page to see if there are any set bits that need to be
816 * flushed out to disk */
817 for (i = 0; i < bitmap->file_pages; i++) {
818 spin_lock_irqsave(&bitmap->lock, flags);
819 if (!bitmap->filemap) {
820 spin_unlock_irqrestore(&bitmap->lock, flags);
821 return;
822 }
823 page = bitmap->filemap[i];
824 dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
825 need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
826 clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
827 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
828 if (dirty)
829 wait = 1;
830 spin_unlock_irqrestore(&bitmap->lock, flags);
831
832 if (dirty | need_write)
833 write_page(bitmap, page, 0);
834 }
835 if (wait) { /* if any writes were performed, we need to wait on them */
836 if (bitmap->file)
837 wait_event(bitmap->write_wait,
838 atomic_read(&bitmap->pending_writes)==0);
839 else
840 md_super_wait(bitmap->mddev);
841 }
842 if (bitmap->flags & BITMAP_WRITE_ERROR)
843 bitmap_file_kick(bitmap);
844 }
845
846 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
847 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
848 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
849 * memory mapping of the bitmap file
850 * Special cases:
851 * if there's no bitmap file, or if the bitmap file had been
852 * previously kicked from the array, we mark all the bits as
853 * 1's in order to cause a full resync.
854 *
855 * We ignore all bits for sectors that end earlier than 'start'.
856 * This is used when reading an out-of-date bitmap...
857 */
858 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
859 {
860 unsigned long i, chunks, index, oldindex, bit;
861 struct page *page = NULL, *oldpage = NULL;
862 unsigned long num_pages, bit_cnt = 0;
863 struct file *file;
864 unsigned long bytes, offset;
865 int outofdate;
866 int ret = -ENOSPC;
867 void *paddr;
868
869 chunks = bitmap->chunks;
870 file = bitmap->file;
871
872 BUG_ON(!file && !bitmap->offset);
873
874 #ifdef INJECT_FAULTS_3
875 outofdate = 1;
876 #else
877 outofdate = bitmap->flags & BITMAP_STALE;
878 #endif
879 if (outofdate)
880 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
881 "recovery\n", bmname(bitmap));
882
883 bytes = (chunks + 7) / 8;
884
885 num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE;
886
887 if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
888 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
889 bmname(bitmap),
890 (unsigned long) i_size_read(file->f_mapping->host),
891 bytes + sizeof(bitmap_super_t));
892 goto err;
893 }
894
895 ret = -ENOMEM;
896
897 bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
898 if (!bitmap->filemap)
899 goto err;
900
901 /* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
902 bitmap->filemap_attr = kzalloc(
903 roundup( DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
904 GFP_KERNEL);
905 if (!bitmap->filemap_attr)
906 goto err;
907
908 oldindex = ~0L;
909
910 for (i = 0; i < chunks; i++) {
911 int b;
912 index = file_page_index(i);
913 bit = file_page_offset(i);
914 if (index != oldindex) { /* this is a new page, read it in */
915 int count;
916 /* unmap the old page, we're done with it */
917 if (index == num_pages-1)
918 count = bytes + sizeof(bitmap_super_t)
919 - index * PAGE_SIZE;
920 else
921 count = PAGE_SIZE;
922 if (index == 0) {
923 /*
924 * if we're here then the superblock page
925 * contains some bits (PAGE_SIZE != sizeof sb)
926 * we've already read it in, so just use it
927 */
928 page = bitmap->sb_page;
929 offset = sizeof(bitmap_super_t);
930 } else if (file) {
931 page = read_page(file, index, bitmap, count);
932 offset = 0;
933 } else {
934 page = read_sb_page(bitmap->mddev, bitmap->offset, index);
935 offset = 0;
936 }
937 if (IS_ERR(page)) { /* read error */
938 ret = PTR_ERR(page);
939 goto err;
940 }
941
942 oldindex = index;
943 oldpage = page;
944
945 if (outofdate) {
946 /*
947 * if bitmap is out of date, dirty the
948 * whole page and write it out
949 */
950 paddr = kmap_atomic(page, KM_USER0);
951 memset(paddr + offset, 0xff,
952 PAGE_SIZE - offset);
953 kunmap_atomic(paddr, KM_USER0);
954 write_page(bitmap, page, 1);
955
956 ret = -EIO;
957 if (bitmap->flags & BITMAP_WRITE_ERROR) {
958 /* release, page not in filemap yet */
959 put_page(page);
960 goto err;
961 }
962 }
963
964 bitmap->filemap[bitmap->file_pages++] = page;
965 bitmap->last_page_size = count;
966 }
967 paddr = kmap_atomic(page, KM_USER0);
968 if (bitmap->flags & BITMAP_HOSTENDIAN)
969 b = test_bit(bit, paddr);
970 else
971 b = ext2_test_bit(bit, paddr);
972 kunmap_atomic(paddr, KM_USER0);
973 if (b) {
974 /* if the disk bit is set, set the memory bit */
975 bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap),
976 ((i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) >= start)
977 );
978 bit_cnt++;
979 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
980 }
981 }
982
983 /* everything went OK */
984 ret = 0;
985 bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
986
987 if (bit_cnt) { /* Kick recovery if any bits were set */
988 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
989 md_wakeup_thread(bitmap->mddev->thread);
990 }
991
992 printk(KERN_INFO "%s: bitmap initialized from disk: "
993 "read %lu/%lu pages, set %lu bits\n",
994 bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt);
995
996 return 0;
997
998 err:
999 printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
1000 bmname(bitmap), ret);
1001 return ret;
1002 }
1003
1004 void bitmap_write_all(struct bitmap *bitmap)
1005 {
1006 /* We don't actually write all bitmap blocks here,
1007 * just flag them as needing to be written
1008 */
1009 int i;
1010
1011 for (i=0; i < bitmap->file_pages; i++)
1012 set_page_attr(bitmap, bitmap->filemap[i],
1013 BITMAP_PAGE_NEEDWRITE);
1014 }
1015
1016
1017 static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
1018 {
1019 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1020 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1021 bitmap->bp[page].count += inc;
1022 /*
1023 if (page == 0) printk("count page 0, offset %llu: %d gives %d\n",
1024 (unsigned long long)offset, inc, bitmap->bp[page].count);
1025 */
1026 bitmap_checkfree(bitmap, page);
1027 }
1028 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1029 sector_t offset, int *blocks,
1030 int create);
1031
1032 /*
1033 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1034 * out to disk
1035 */
1036
1037 void bitmap_daemon_work(struct bitmap *bitmap)
1038 {
1039 unsigned long j;
1040 unsigned long flags;
1041 struct page *page = NULL, *lastpage = NULL;
1042 int blocks;
1043 void *paddr;
1044
1045 if (bitmap == NULL)
1046 return;
1047 if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ))
1048 goto done;
1049
1050 bitmap->daemon_lastrun = jiffies;
1051 if (bitmap->allclean) {
1052 bitmap->mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1053 return;
1054 }
1055 bitmap->allclean = 1;
1056
1057 for (j = 0; j < bitmap->chunks; j++) {
1058 bitmap_counter_t *bmc;
1059 spin_lock_irqsave(&bitmap->lock, flags);
1060 if (!bitmap->filemap) {
1061 /* error or shutdown */
1062 spin_unlock_irqrestore(&bitmap->lock, flags);
1063 break;
1064 }
1065
1066 page = filemap_get_page(bitmap, j);
1067
1068 if (page != lastpage) {
1069 /* skip this page unless it's marked as needing cleaning */
1070 if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
1071 int need_write = test_page_attr(bitmap, page,
1072 BITMAP_PAGE_NEEDWRITE);
1073 if (need_write)
1074 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1075
1076 spin_unlock_irqrestore(&bitmap->lock, flags);
1077 if (need_write) {
1078 write_page(bitmap, page, 0);
1079 bitmap->allclean = 0;
1080 }
1081 continue;
1082 }
1083
1084 /* grab the new page, sync and release the old */
1085 if (lastpage != NULL) {
1086 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1087 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1088 spin_unlock_irqrestore(&bitmap->lock, flags);
1089 write_page(bitmap, lastpage, 0);
1090 } else {
1091 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1092 spin_unlock_irqrestore(&bitmap->lock, flags);
1093 }
1094 } else
1095 spin_unlock_irqrestore(&bitmap->lock, flags);
1096 lastpage = page;
1097 /*
1098 printk("bitmap clean at page %lu\n", j);
1099 */
1100 spin_lock_irqsave(&bitmap->lock, flags);
1101 clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1102 }
1103 bmc = bitmap_get_counter(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1104 &blocks, 0);
1105 if (bmc) {
1106 /*
1107 if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc);
1108 */
1109 if (*bmc)
1110 bitmap->allclean = 0;
1111
1112 if (*bmc == 2) {
1113 *bmc=1; /* maybe clear the bit next time */
1114 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1115 } else if (*bmc == 1) {
1116 /* we can clear the bit */
1117 *bmc = 0;
1118 bitmap_count_page(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1119 -1);
1120
1121 /* clear the bit */
1122 paddr = kmap_atomic(page, KM_USER0);
1123 if (bitmap->flags & BITMAP_HOSTENDIAN)
1124 clear_bit(file_page_offset(j), paddr);
1125 else
1126 ext2_clear_bit(file_page_offset(j), paddr);
1127 kunmap_atomic(paddr, KM_USER0);
1128 }
1129 }
1130 spin_unlock_irqrestore(&bitmap->lock, flags);
1131 }
1132
1133 /* now sync the final page */
1134 if (lastpage != NULL) {
1135 spin_lock_irqsave(&bitmap->lock, flags);
1136 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1137 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1138 spin_unlock_irqrestore(&bitmap->lock, flags);
1139 write_page(bitmap, lastpage, 0);
1140 } else {
1141 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1142 spin_unlock_irqrestore(&bitmap->lock, flags);
1143 }
1144 }
1145
1146 done:
1147 if (bitmap->allclean == 0)
1148 bitmap->mddev->thread->timeout = bitmap->daemon_sleep * HZ;
1149 }
1150
1151 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1152 sector_t offset, int *blocks,
1153 int create)
1154 {
1155 /* If 'create', we might release the lock and reclaim it.
1156 * The lock must have been taken with interrupts enabled.
1157 * If !create, we don't release the lock.
1158 */
1159 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1160 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1161 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1162 sector_t csize;
1163
1164 if (bitmap_checkpage(bitmap, page, create) < 0) {
1165 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1166 *blocks = csize - (offset & (csize- 1));
1167 return NULL;
1168 }
1169 /* now locked ... */
1170
1171 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1172 /* should we use the first or second counter field
1173 * of the hijacked pointer? */
1174 int hi = (pageoff > PAGE_COUNTER_MASK);
1175 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) +
1176 PAGE_COUNTER_SHIFT - 1);
1177 *blocks = csize - (offset & (csize- 1));
1178 return &((bitmap_counter_t *)
1179 &bitmap->bp[page].map)[hi];
1180 } else { /* page is allocated */
1181 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1182 *blocks = csize - (offset & (csize- 1));
1183 return (bitmap_counter_t *)
1184 &(bitmap->bp[page].map[pageoff]);
1185 }
1186 }
1187
1188 int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1189 {
1190 if (!bitmap) return 0;
1191
1192 if (behind) {
1193 atomic_inc(&bitmap->behind_writes);
1194 PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n",
1195 atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
1196 }
1197
1198 while (sectors) {
1199 int blocks;
1200 bitmap_counter_t *bmc;
1201
1202 spin_lock_irq(&bitmap->lock);
1203 bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
1204 if (!bmc) {
1205 spin_unlock_irq(&bitmap->lock);
1206 return 0;
1207 }
1208
1209 if (unlikely((*bmc & COUNTER_MAX) == COUNTER_MAX)) {
1210 DEFINE_WAIT(__wait);
1211 /* note that it is safe to do the prepare_to_wait
1212 * after the test as long as we do it before dropping
1213 * the spinlock.
1214 */
1215 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1216 TASK_UNINTERRUPTIBLE);
1217 spin_unlock_irq(&bitmap->lock);
1218 blk_unplug(bitmap->mddev->queue);
1219 schedule();
1220 finish_wait(&bitmap->overflow_wait, &__wait);
1221 continue;
1222 }
1223
1224 switch(*bmc) {
1225 case 0:
1226 bitmap_file_set_bit(bitmap, offset);
1227 bitmap_count_page(bitmap,offset, 1);
1228 blk_plug_device(bitmap->mddev->queue);
1229 /* fall through */
1230 case 1:
1231 *bmc = 2;
1232 }
1233
1234 (*bmc)++;
1235
1236 spin_unlock_irq(&bitmap->lock);
1237
1238 offset += blocks;
1239 if (sectors > blocks)
1240 sectors -= blocks;
1241 else sectors = 0;
1242 }
1243 bitmap->allclean = 0;
1244 return 0;
1245 }
1246
1247 void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1248 int success, int behind)
1249 {
1250 if (!bitmap) return;
1251 if (behind) {
1252 atomic_dec(&bitmap->behind_writes);
1253 PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n",
1254 atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
1255 }
1256
1257 while (sectors) {
1258 int blocks;
1259 unsigned long flags;
1260 bitmap_counter_t *bmc;
1261
1262 spin_lock_irqsave(&bitmap->lock, flags);
1263 bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
1264 if (!bmc) {
1265 spin_unlock_irqrestore(&bitmap->lock, flags);
1266 return;
1267 }
1268
1269 if (!success && ! (*bmc & NEEDED_MASK))
1270 *bmc |= NEEDED_MASK;
1271
1272 if ((*bmc & COUNTER_MAX) == COUNTER_MAX)
1273 wake_up(&bitmap->overflow_wait);
1274
1275 (*bmc)--;
1276 if (*bmc <= 2) {
1277 set_page_attr(bitmap,
1278 filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1279 BITMAP_PAGE_CLEAN);
1280 }
1281 spin_unlock_irqrestore(&bitmap->lock, flags);
1282 offset += blocks;
1283 if (sectors > blocks)
1284 sectors -= blocks;
1285 else sectors = 0;
1286 }
1287 }
1288
1289 int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks,
1290 int degraded)
1291 {
1292 bitmap_counter_t *bmc;
1293 int rv;
1294 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1295 *blocks = 1024;
1296 return 1; /* always resync if no bitmap */
1297 }
1298 spin_lock_irq(&bitmap->lock);
1299 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1300 rv = 0;
1301 if (bmc) {
1302 /* locked */
1303 if (RESYNC(*bmc))
1304 rv = 1;
1305 else if (NEEDED(*bmc)) {
1306 rv = 1;
1307 if (!degraded) { /* don't set/clear bits if degraded */
1308 *bmc |= RESYNC_MASK;
1309 *bmc &= ~NEEDED_MASK;
1310 }
1311 }
1312 }
1313 spin_unlock_irq(&bitmap->lock);
1314 bitmap->allclean = 0;
1315 return rv;
1316 }
1317
1318 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted)
1319 {
1320 bitmap_counter_t *bmc;
1321 unsigned long flags;
1322 /*
1323 if (offset == 0) printk("bitmap_end_sync 0 (%d)\n", aborted);
1324 */ if (bitmap == NULL) {
1325 *blocks = 1024;
1326 return;
1327 }
1328 spin_lock_irqsave(&bitmap->lock, flags);
1329 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1330 if (bmc == NULL)
1331 goto unlock;
1332 /* locked */
1333 /*
1334 if (offset == 0) printk("bitmap_end sync found 0x%x, blocks %d\n", *bmc, *blocks);
1335 */
1336 if (RESYNC(*bmc)) {
1337 *bmc &= ~RESYNC_MASK;
1338
1339 if (!NEEDED(*bmc) && aborted)
1340 *bmc |= NEEDED_MASK;
1341 else {
1342 if (*bmc <= 2) {
1343 set_page_attr(bitmap,
1344 filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1345 BITMAP_PAGE_CLEAN);
1346 }
1347 }
1348 }
1349 unlock:
1350 spin_unlock_irqrestore(&bitmap->lock, flags);
1351 bitmap->allclean = 0;
1352 }
1353
1354 void bitmap_close_sync(struct bitmap *bitmap)
1355 {
1356 /* Sync has finished, and any bitmap chunks that weren't synced
1357 * properly have been aborted. It remains to us to clear the
1358 * RESYNC bit wherever it is still on
1359 */
1360 sector_t sector = 0;
1361 int blocks;
1362 if (!bitmap)
1363 return;
1364 while (sector < bitmap->mddev->resync_max_sectors) {
1365 bitmap_end_sync(bitmap, sector, &blocks, 0);
1366 sector += blocks;
1367 }
1368 }
1369
1370 void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
1371 {
1372 sector_t s = 0;
1373 int blocks;
1374
1375 if (!bitmap)
1376 return;
1377 if (sector == 0) {
1378 bitmap->last_end_sync = jiffies;
1379 return;
1380 }
1381 if (time_before(jiffies, (bitmap->last_end_sync
1382 + bitmap->daemon_sleep * HZ)))
1383 return;
1384 wait_event(bitmap->mddev->recovery_wait,
1385 atomic_read(&bitmap->mddev->recovery_active) == 0);
1386
1387 sector &= ~((1ULL << CHUNK_BLOCK_SHIFT(bitmap)) - 1);
1388 s = 0;
1389 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1390 bitmap_end_sync(bitmap, s, &blocks, 0);
1391 s += blocks;
1392 }
1393 bitmap->last_end_sync = jiffies;
1394 }
1395
1396 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1397 {
1398 /* For each chunk covered by any of these sectors, set the
1399 * counter to 1 and set resync_needed. They should all
1400 * be 0 at this point
1401 */
1402
1403 int secs;
1404 bitmap_counter_t *bmc;
1405 spin_lock_irq(&bitmap->lock);
1406 bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
1407 if (!bmc) {
1408 spin_unlock_irq(&bitmap->lock);
1409 return;
1410 }
1411 if (! *bmc) {
1412 struct page *page;
1413 *bmc = 1 | (needed?NEEDED_MASK:0);
1414 bitmap_count_page(bitmap, offset, 1);
1415 page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
1416 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1417 }
1418 spin_unlock_irq(&bitmap->lock);
1419 bitmap->allclean = 0;
1420 }
1421
1422 /* dirty the memory and file bits for bitmap chunks "s" to "e" */
1423 void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1424 {
1425 unsigned long chunk;
1426
1427 for (chunk = s; chunk <= e; chunk++) {
1428 sector_t sec = chunk << CHUNK_BLOCK_SHIFT(bitmap);
1429 bitmap_set_memory_bits(bitmap, sec, 1);
1430 bitmap_file_set_bit(bitmap, sec);
1431 }
1432 }
1433
1434 /*
1435 * flush out any pending updates
1436 */
1437 void bitmap_flush(mddev_t *mddev)
1438 {
1439 struct bitmap *bitmap = mddev->bitmap;
1440 int sleep;
1441
1442 if (!bitmap) /* there was no bitmap */
1443 return;
1444
1445 /* run the daemon_work three time to ensure everything is flushed
1446 * that can be
1447 */
1448 sleep = bitmap->daemon_sleep;
1449 bitmap->daemon_sleep = 0;
1450 bitmap_daemon_work(bitmap);
1451 bitmap_daemon_work(bitmap);
1452 bitmap_daemon_work(bitmap);
1453 bitmap->daemon_sleep = sleep;
1454 bitmap_update_sb(bitmap);
1455 }
1456
1457 /*
1458 * free memory that was allocated
1459 */
1460 static void bitmap_free(struct bitmap *bitmap)
1461 {
1462 unsigned long k, pages;
1463 struct bitmap_page *bp;
1464
1465 if (!bitmap) /* there was no bitmap */
1466 return;
1467
1468 /* release the bitmap file and kill the daemon */
1469 bitmap_file_put(bitmap);
1470
1471 bp = bitmap->bp;
1472 pages = bitmap->pages;
1473
1474 /* free all allocated memory */
1475
1476 if (bp) /* deallocate the page memory */
1477 for (k = 0; k < pages; k++)
1478 if (bp[k].map && !bp[k].hijacked)
1479 kfree(bp[k].map);
1480 kfree(bp);
1481 kfree(bitmap);
1482 }
1483 void bitmap_destroy(mddev_t *mddev)
1484 {
1485 struct bitmap *bitmap = mddev->bitmap;
1486
1487 if (!bitmap) /* there was no bitmap */
1488 return;
1489
1490 mddev->bitmap = NULL; /* disconnect from the md device */
1491 if (mddev->thread)
1492 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1493
1494 bitmap_free(bitmap);
1495 }
1496
1497 /*
1498 * initialize the bitmap structure
1499 * if this returns an error, bitmap_destroy must be called to do clean up
1500 */
1501 int bitmap_create(mddev_t *mddev)
1502 {
1503 struct bitmap *bitmap;
1504 unsigned long blocks = mddev->resync_max_sectors;
1505 unsigned long chunks;
1506 unsigned long pages;
1507 struct file *file = mddev->bitmap_file;
1508 int err;
1509 sector_t start;
1510
1511 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1512
1513 if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */
1514 return 0;
1515
1516 BUG_ON(file && mddev->bitmap_offset);
1517
1518 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1519 if (!bitmap)
1520 return -ENOMEM;
1521
1522 spin_lock_init(&bitmap->lock);
1523 atomic_set(&bitmap->pending_writes, 0);
1524 init_waitqueue_head(&bitmap->write_wait);
1525 init_waitqueue_head(&bitmap->overflow_wait);
1526
1527 bitmap->mddev = mddev;
1528
1529 bitmap->file = file;
1530 bitmap->offset = mddev->bitmap_offset;
1531 if (file) {
1532 get_file(file);
1533 do_sync_mapping_range(file->f_mapping, 0, LLONG_MAX,
1534 SYNC_FILE_RANGE_WAIT_BEFORE |
1535 SYNC_FILE_RANGE_WRITE |
1536 SYNC_FILE_RANGE_WAIT_AFTER);
1537 }
1538 /* read superblock from bitmap file (this sets bitmap->chunksize) */
1539 err = bitmap_read_sb(bitmap);
1540 if (err)
1541 goto error;
1542
1543 bitmap->chunkshift = ffz(~bitmap->chunksize);
1544
1545 /* now that chunksize and chunkshift are set, we can use these macros */
1546 chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) /
1547 CHUNK_BLOCK_RATIO(bitmap);
1548 pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1549
1550 BUG_ON(!pages);
1551
1552 bitmap->chunks = chunks;
1553 bitmap->pages = pages;
1554 bitmap->missing_pages = pages;
1555 bitmap->counter_bits = COUNTER_BITS;
1556
1557 bitmap->syncchunk = ~0UL;
1558
1559 #ifdef INJECT_FATAL_FAULT_1
1560 bitmap->bp = NULL;
1561 #else
1562 bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1563 #endif
1564 err = -ENOMEM;
1565 if (!bitmap->bp)
1566 goto error;
1567
1568 /* now that we have some pages available, initialize the in-memory
1569 * bitmap from the on-disk bitmap */
1570 start = 0;
1571 if (mddev->degraded == 0
1572 || bitmap->events_cleared == mddev->events)
1573 /* no need to keep dirty bits to optimise a re-add of a missing device */
1574 start = mddev->recovery_cp;
1575 err = bitmap_init_from_disk(bitmap, start);
1576
1577 if (err)
1578 goto error;
1579
1580 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1581 pages, bmname(bitmap));
1582
1583 mddev->bitmap = bitmap;
1584
1585 mddev->thread->timeout = bitmap->daemon_sleep * HZ;
1586
1587 bitmap_update_sb(bitmap);
1588
1589 return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
1590
1591 error:
1592 bitmap_free(bitmap);
1593 return err;
1594 }
1595
1596 /* the bitmap API -- for raid personalities */
1597 EXPORT_SYMBOL(bitmap_startwrite);
1598 EXPORT_SYMBOL(bitmap_endwrite);
1599 EXPORT_SYMBOL(bitmap_start_sync);
1600 EXPORT_SYMBOL(bitmap_end_sync);
1601 EXPORT_SYMBOL(bitmap_unplug);
1602 EXPORT_SYMBOL(bitmap_close_sync);
1603 EXPORT_SYMBOL(bitmap_cond_end_sync);
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