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-rw-r--r--drivers/md/bitmap.c1586
1 files changed, 1586 insertions, 0 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
new file mode 100644
index 000000000000..95980ad6b27b
--- /dev/null
+++ b/drivers/md/bitmap.c
@@ -0,0 +1,1586 @@
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/version.h>
25#include <linux/errno.h>
26#include <linux/slab.h>
27#include <linux/init.h>
28#include <linux/config.h>
29#include <linux/timer.h>
30#include <linux/sched.h>
31#include <linux/list.h>
32#include <linux/file.h>
33#include <linux/mount.h>
34#include <linux/buffer_head.h>
35#include <linux/raid/md.h>
36#include <linux/raid/bitmap.h>
37
38/* debug macros */
39
40#define DEBUG 0
41
42#if DEBUG
43/* these are for debugging purposes only! */
44
45/* define one and only one of these */
46#define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */
47#define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/
48#define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */
49#define INJECT_FAULTS_4 0 /* undef */
50#define INJECT_FAULTS_5 0 /* undef */
51#define INJECT_FAULTS_6 0
52
53/* if these are defined, the driver will fail! debug only */
54#define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */
55#define INJECT_FATAL_FAULT_2 0 /* undef */
56#define INJECT_FATAL_FAULT_3 0 /* undef */
57#endif
58
59//#define DPRINTK PRINTK /* set this NULL to avoid verbose debug output */
60#define DPRINTK(x...) do { } while(0)
61
62#ifndef PRINTK
63# if DEBUG > 0
64# define PRINTK(x...) printk(KERN_DEBUG x)
65# else
66# define PRINTK(x...)
67# endif
68#endif
69
70static inline char * bmname(struct bitmap *bitmap)
71{
72 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
73}
74
75
76/*
77 * test if the bitmap is active
78 */
79int bitmap_active(struct bitmap *bitmap)
80{
81 unsigned long flags;
82 int res = 0;
83
84 if (!bitmap)
85 return res;
86 spin_lock_irqsave(&bitmap->lock, flags);
87 res = bitmap->flags & BITMAP_ACTIVE;
88 spin_unlock_irqrestore(&bitmap->lock, flags);
89 return res;
90}
91
92#define WRITE_POOL_SIZE 256
93/* mempool for queueing pending writes on the bitmap file */
94static void *write_pool_alloc(unsigned int gfp_flags, void *data)
95{
96 return kmalloc(sizeof(struct page_list), gfp_flags);
97}
98
99static void write_pool_free(void *ptr, void *data)
100{
101 kfree(ptr);
102}
103
104/*
105 * just a placeholder - calls kmalloc for bitmap pages
106 */
107static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
108{
109 unsigned char *page;
110
111#if INJECT_FAULTS_1
112 page = NULL;
113#else
114 page = kmalloc(PAGE_SIZE, GFP_NOIO);
115#endif
116 if (!page)
117 printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
118 else
119 PRINTK("%s: bitmap_alloc_page: allocated page at %p\n",
120 bmname(bitmap), page);
121 return page;
122}
123
124/*
125 * for now just a placeholder -- just calls kfree for bitmap pages
126 */
127static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page)
128{
129 PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page);
130 kfree(page);
131}
132
133/*
134 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
135 *
136 * 1) check to see if this page is allocated, if it's not then try to alloc
137 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
138 * page pointer directly as a counter
139 *
140 * if we find our page, we increment the page's refcount so that it stays
141 * allocated while we're using it
142 */
143static int bitmap_checkpage(struct bitmap *bitmap, unsigned long page, int create)
144{
145 unsigned char *mappage;
146
147 if (page >= bitmap->pages) {
148 printk(KERN_ALERT
149 "%s: invalid bitmap page request: %lu (> %lu)\n",
150 bmname(bitmap), page, bitmap->pages-1);
151 return -EINVAL;
152 }
153
154
155 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
156 return 0;
157
158 if (bitmap->bp[page].map) /* page is already allocated, just return */
159 return 0;
160
161 if (!create)
162 return -ENOENT;
163
164 spin_unlock_irq(&bitmap->lock);
165
166 /* this page has not been allocated yet */
167
168 if ((mappage = bitmap_alloc_page(bitmap)) == NULL) {
169 PRINTK("%s: bitmap map page allocation failed, hijacking\n",
170 bmname(bitmap));
171 /* failed - set the hijacked flag so that we can use the
172 * pointer as a counter */
173 spin_lock_irq(&bitmap->lock);
174 if (!bitmap->bp[page].map)
175 bitmap->bp[page].hijacked = 1;
176 goto out;
177 }
178
179 /* got a page */
180
181 spin_lock_irq(&bitmap->lock);
182
183 /* recheck the page */
184
185 if (bitmap->bp[page].map || bitmap->bp[page].hijacked) {
186 /* somebody beat us to getting the page */
187 bitmap_free_page(bitmap, mappage);
188 return 0;
189 }
190
191 /* no page was in place and we have one, so install it */
192
193 memset(mappage, 0, PAGE_SIZE);
194 bitmap->bp[page].map = mappage;
195 bitmap->missing_pages--;
196out:
197 return 0;
198}
199
200
201/* if page is completely empty, put it back on the free list, or dealloc it */
202/* if page was hijacked, unmark the flag so it might get alloced next time */
203/* Note: lock should be held when calling this */
204static inline void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
205{
206 char *ptr;
207
208 if (bitmap->bp[page].count) /* page is still busy */
209 return;
210
211 /* page is no longer in use, it can be released */
212
213 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
214 bitmap->bp[page].hijacked = 0;
215 bitmap->bp[page].map = NULL;
216 return;
217 }
218
219 /* normal case, free the page */
220
221#if 0
222/* actually ... let's not. We will probably need the page again exactly when
223 * memory is tight and we are flusing to disk
224 */
225 return;
226#else
227 ptr = bitmap->bp[page].map;
228 bitmap->bp[page].map = NULL;
229 bitmap->missing_pages++;
230 bitmap_free_page(bitmap, ptr);
231 return;
232#endif
233}
234
235
236/*
237 * bitmap file handling - read and write the bitmap file and its superblock
238 */
239
240/* copy the pathname of a file to a buffer */
241char *file_path(struct file *file, char *buf, int count)
242{
243 struct dentry *d;
244 struct vfsmount *v;
245
246 if (!buf)
247 return NULL;
248
249 d = file->f_dentry;
250 v = file->f_vfsmnt;
251
252 buf = d_path(d, v, buf, count);
253
254 return IS_ERR(buf) ? NULL : buf;
255}
256
257/*
258 * basic page I/O operations
259 */
260
261/* IO operations when bitmap is stored near all superblocks */
262static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long index)
263{
264 /* choose a good rdev and read the page from there */
265
266 mdk_rdev_t *rdev;
267 struct list_head *tmp;
268 struct page *page = alloc_page(GFP_KERNEL);
269 sector_t target;
270
271 if (!page)
272 return ERR_PTR(-ENOMEM);
273 do {
274 ITERATE_RDEV(mddev, rdev, tmp)
275 if (rdev->in_sync && !rdev->faulty)
276 goto found;
277 return ERR_PTR(-EIO);
278
279 found:
280 target = (rdev->sb_offset << 1) + offset + index * (PAGE_SIZE/512);
281
282 } while (!sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ));
283
284 page->index = index;
285 return page;
286}
287
288static int write_sb_page(mddev_t *mddev, long offset, struct page *page, int wait)
289{
290 mdk_rdev_t *rdev;
291 struct list_head *tmp;
292
293 ITERATE_RDEV(mddev, rdev, tmp)
294 if (rdev->in_sync && !rdev->faulty)
295 md_super_write(mddev, rdev,
296 (rdev->sb_offset<<1) + offset
297 + page->index * (PAGE_SIZE/512),
298 PAGE_SIZE,
299 page);
300
301 if (wait)
302 wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0);
303 return 0;
304}
305
306/*
307 * write out a page to a file
308 */
309static int write_page(struct bitmap *bitmap, struct page *page, int wait)
310{
311 int ret = -ENOMEM;
312
313 if (bitmap->file == NULL)
314 return write_sb_page(bitmap->mddev, bitmap->offset, page, wait);
315
316 if (wait)
317 lock_page(page);
318 else {
319 if (TestSetPageLocked(page))
320 return -EAGAIN; /* already locked */
321 if (PageWriteback(page)) {
322 unlock_page(page);
323 return -EAGAIN;
324 }
325 }
326
327 ret = page->mapping->a_ops->prepare_write(NULL, page, 0, PAGE_SIZE);
328 if (!ret)
329 ret = page->mapping->a_ops->commit_write(NULL, page, 0,
330 PAGE_SIZE);
331 if (ret) {
332 unlock_page(page);
333 return ret;
334 }
335
336 set_page_dirty(page); /* force it to be written out */
337
338 if (!wait) {
339 /* add to list to be waited for by daemon */
340 struct page_list *item = mempool_alloc(bitmap->write_pool, GFP_NOIO);
341 item->page = page;
342 page_cache_get(page);
343 spin_lock(&bitmap->write_lock);
344 list_add(&item->list, &bitmap->complete_pages);
345 spin_unlock(&bitmap->write_lock);
346 md_wakeup_thread(bitmap->writeback_daemon);
347 }
348 return write_one_page(page, wait);
349}
350
351/* read a page from a file, pinning it into cache, and return bytes_read */
352static struct page *read_page(struct file *file, unsigned long index,
353 unsigned long *bytes_read)
354{
355 struct inode *inode = file->f_mapping->host;
356 struct page *page = NULL;
357 loff_t isize = i_size_read(inode);
358 unsigned long end_index = isize >> PAGE_CACHE_SHIFT;
359
360 PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_CACHE_SIZE,
361 (unsigned long long)index << PAGE_CACHE_SHIFT);
362
363 page = read_cache_page(inode->i_mapping, index,
364 (filler_t *)inode->i_mapping->a_ops->readpage, file);
365 if (IS_ERR(page))
366 goto out;
367 wait_on_page_locked(page);
368 if (!PageUptodate(page) || PageError(page)) {
369 page_cache_release(page);
370 page = ERR_PTR(-EIO);
371 goto out;
372 }
373
374 if (index > end_index) /* we have read beyond EOF */
375 *bytes_read = 0;
376 else if (index == end_index) /* possible short read */
377 *bytes_read = isize & ~PAGE_CACHE_MASK;
378 else
379 *bytes_read = PAGE_CACHE_SIZE; /* got a full page */
380out:
381 if (IS_ERR(page))
382 printk(KERN_ALERT "md: bitmap read error: (%dB @ %Lu): %ld\n",
383 (int)PAGE_CACHE_SIZE,
384 (unsigned long long)index << PAGE_CACHE_SHIFT,
385 PTR_ERR(page));
386 return page;
387}
388
389/*
390 * bitmap file superblock operations
391 */
392
393/* update the event counter and sync the superblock to disk */
394int bitmap_update_sb(struct bitmap *bitmap)
395{
396 bitmap_super_t *sb;
397 unsigned long flags;
398
399 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
400 return 0;
401 spin_lock_irqsave(&bitmap->lock, flags);
402 if (!bitmap->sb_page) { /* no superblock */
403 spin_unlock_irqrestore(&bitmap->lock, flags);
404 return 0;
405 }
406 spin_unlock_irqrestore(&bitmap->lock, flags);
407 sb = (bitmap_super_t *)kmap(bitmap->sb_page);
408 sb->events = cpu_to_le64(bitmap->mddev->events);
409 if (!bitmap->mddev->degraded)
410 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
411 kunmap(bitmap->sb_page);
412 return write_page(bitmap, bitmap->sb_page, 1);
413}
414
415/* print out the bitmap file superblock */
416void bitmap_print_sb(struct bitmap *bitmap)
417{
418 bitmap_super_t *sb;
419
420 if (!bitmap || !bitmap->sb_page)
421 return;
422 sb = (bitmap_super_t *)kmap(bitmap->sb_page);
423 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
424 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
425 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
426 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
427 *(__u32 *)(sb->uuid+0),
428 *(__u32 *)(sb->uuid+4),
429 *(__u32 *)(sb->uuid+8),
430 *(__u32 *)(sb->uuid+12));
431 printk(KERN_DEBUG " events: %llu\n",
432 (unsigned long long) le64_to_cpu(sb->events));
433 printk(KERN_DEBUG "events cleared: %llu\n",
434 (unsigned long long) le64_to_cpu(sb->events_cleared));
435 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
436 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
437 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
438 printk(KERN_DEBUG " sync size: %llu KB\n",
439 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
440 kunmap(bitmap->sb_page);
441}
442
443/* read the superblock from the bitmap file and initialize some bitmap fields */
444static int bitmap_read_sb(struct bitmap *bitmap)
445{
446 char *reason = NULL;
447 bitmap_super_t *sb;
448 unsigned long chunksize, daemon_sleep;
449 unsigned long bytes_read;
450 unsigned long long events;
451 int err = -EINVAL;
452
453 /* page 0 is the superblock, read it... */
454 if (bitmap->file)
455 bitmap->sb_page = read_page(bitmap->file, 0, &bytes_read);
456 else {
457 bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0);
458 bytes_read = PAGE_SIZE;
459 }
460 if (IS_ERR(bitmap->sb_page)) {
461 err = PTR_ERR(bitmap->sb_page);
462 bitmap->sb_page = NULL;
463 return err;
464 }
465
466 sb = (bitmap_super_t *)kmap(bitmap->sb_page);
467
468 if (bytes_read < sizeof(*sb)) { /* short read */
469 printk(KERN_INFO "%s: bitmap file superblock truncated\n",
470 bmname(bitmap));
471 err = -ENOSPC;
472 goto out;
473 }
474
475 chunksize = le32_to_cpu(sb->chunksize);
476 daemon_sleep = le32_to_cpu(sb->daemon_sleep);
477
478 /* verify that the bitmap-specific fields are valid */
479 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
480 reason = "bad magic";
481 else if (sb->version != cpu_to_le32(BITMAP_MAJOR))
482 reason = "unrecognized superblock version";
483 else if (chunksize < 512 || chunksize > (1024 * 1024 * 4))
484 reason = "bitmap chunksize out of range (512B - 4MB)";
485 else if ((1 << ffz(~chunksize)) != chunksize)
486 reason = "bitmap chunksize not a power of 2";
487 else if (daemon_sleep < 1 || daemon_sleep > 15)
488 reason = "daemon sleep period out of range";
489 if (reason) {
490 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
491 bmname(bitmap), reason);
492 goto out;
493 }
494
495 /* keep the array size field of the bitmap superblock up to date */
496 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
497
498 if (!bitmap->mddev->persistent)
499 goto success;
500
501 /*
502 * if we have a persistent array superblock, compare the
503 * bitmap's UUID and event counter to the mddev's
504 */
505 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
506 printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n",
507 bmname(bitmap));
508 goto out;
509 }
510 events = le64_to_cpu(sb->events);
511 if (events < bitmap->mddev->events) {
512 printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) "
513 "-- forcing full recovery\n", bmname(bitmap), events,
514 (unsigned long long) bitmap->mddev->events);
515 sb->state |= BITMAP_STALE;
516 }
517success:
518 /* assign fields using values from superblock */
519 bitmap->chunksize = chunksize;
520 bitmap->daemon_sleep = daemon_sleep;
521 bitmap->flags |= sb->state;
522 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
523 err = 0;
524out:
525 kunmap(bitmap->sb_page);
526 if (err)
527 bitmap_print_sb(bitmap);
528 return err;
529}
530
531enum bitmap_mask_op {
532 MASK_SET,
533 MASK_UNSET
534};
535
536/* record the state of the bitmap in the superblock */
537static void bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
538 enum bitmap_mask_op op)
539{
540 bitmap_super_t *sb;
541 unsigned long flags;
542
543 spin_lock_irqsave(&bitmap->lock, flags);
544 if (!bitmap || !bitmap->sb_page) { /* can't set the state */
545 spin_unlock_irqrestore(&bitmap->lock, flags);
546 return;
547 }
548 page_cache_get(bitmap->sb_page);
549 spin_unlock_irqrestore(&bitmap->lock, flags);
550 sb = (bitmap_super_t *)kmap(bitmap->sb_page);
551 switch (op) {
552 case MASK_SET: sb->state |= bits;
553 break;
554 case MASK_UNSET: sb->state &= ~bits;
555 break;
556 default: BUG();
557 }
558 kunmap(bitmap->sb_page);
559 page_cache_release(bitmap->sb_page);
560}
561
562/*
563 * general bitmap file operations
564 */
565
566/* calculate the index of the page that contains this bit */
567static inline unsigned long file_page_index(unsigned long chunk)
568{
569 return CHUNK_BIT_OFFSET(chunk) >> PAGE_BIT_SHIFT;
570}
571
572/* calculate the (bit) offset of this bit within a page */
573static inline unsigned long file_page_offset(unsigned long chunk)
574{
575 return CHUNK_BIT_OFFSET(chunk) & (PAGE_BITS - 1);
576}
577
578/*
579 * return a pointer to the page in the filemap that contains the given bit
580 *
581 * this lookup is complicated by the fact that the bitmap sb might be exactly
582 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
583 * 0 or page 1
584 */
585static inline struct page *filemap_get_page(struct bitmap *bitmap,
586 unsigned long chunk)
587{
588 return bitmap->filemap[file_page_index(chunk) - file_page_index(0)];
589}
590
591
592static void bitmap_file_unmap(struct bitmap *bitmap)
593{
594 struct page **map, *sb_page;
595 unsigned long *attr;
596 int pages;
597 unsigned long flags;
598
599 spin_lock_irqsave(&bitmap->lock, flags);
600 map = bitmap->filemap;
601 bitmap->filemap = NULL;
602 attr = bitmap->filemap_attr;
603 bitmap->filemap_attr = NULL;
604 pages = bitmap->file_pages;
605 bitmap->file_pages = 0;
606 sb_page = bitmap->sb_page;
607 bitmap->sb_page = NULL;
608 spin_unlock_irqrestore(&bitmap->lock, flags);
609
610 while (pages--)
611 if (map[pages]->index != 0) /* 0 is sb_page, release it below */
612 page_cache_release(map[pages]);
613 kfree(map);
614 kfree(attr);
615
616 if (sb_page)
617 page_cache_release(sb_page);
618}
619
620static void bitmap_stop_daemons(struct bitmap *bitmap);
621
622/* dequeue the next item in a page list -- don't call from irq context */
623static struct page_list *dequeue_page(struct bitmap *bitmap)
624{
625 struct page_list *item = NULL;
626 struct list_head *head = &bitmap->complete_pages;
627
628 spin_lock(&bitmap->write_lock);
629 if (list_empty(head))
630 goto out;
631 item = list_entry(head->prev, struct page_list, list);
632 list_del(head->prev);
633out:
634 spin_unlock(&bitmap->write_lock);
635 return item;
636}
637
638static void drain_write_queues(struct bitmap *bitmap)
639{
640 struct page_list *item;
641
642 while ((item = dequeue_page(bitmap))) {
643 /* don't bother to wait */
644 page_cache_release(item->page);
645 mempool_free(item, bitmap->write_pool);
646 }
647
648 wake_up(&bitmap->write_wait);
649}
650
651static void bitmap_file_put(struct bitmap *bitmap)
652{
653 struct file *file;
654 struct inode *inode;
655 unsigned long flags;
656
657 spin_lock_irqsave(&bitmap->lock, flags);
658 file = bitmap->file;
659 bitmap->file = NULL;
660 spin_unlock_irqrestore(&bitmap->lock, flags);
661
662 bitmap_stop_daemons(bitmap);
663
664 drain_write_queues(bitmap);
665
666 bitmap_file_unmap(bitmap);
667
668 if (file) {
669 inode = file->f_mapping->host;
670 spin_lock(&inode->i_lock);
671 atomic_set(&inode->i_writecount, 1); /* allow writes again */
672 spin_unlock(&inode->i_lock);
673 fput(file);
674 }
675}
676
677
678/*
679 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
680 * then it is no longer reliable, so we stop using it and we mark the file
681 * as failed in the superblock
682 */
683static void bitmap_file_kick(struct bitmap *bitmap)
684{
685 char *path, *ptr = NULL;
686
687 bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET);
688 bitmap_update_sb(bitmap);
689
690 if (bitmap->file) {
691 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
692 if (path)
693 ptr = file_path(bitmap->file, path, PAGE_SIZE);
694
695 printk(KERN_ALERT "%s: kicking failed bitmap file %s from array!\n",
696 bmname(bitmap), ptr ? ptr : "");
697
698 kfree(path);
699 }
700
701 bitmap_file_put(bitmap);
702
703 return;
704}
705
706enum bitmap_page_attr {
707 BITMAP_PAGE_DIRTY = 1, // there are set bits that need to be synced
708 BITMAP_PAGE_CLEAN = 2, // there are bits that might need to be cleared
709 BITMAP_PAGE_NEEDWRITE=4, // there are cleared bits that need to be synced
710};
711
712static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
713 enum bitmap_page_attr attr)
714{
715 bitmap->filemap_attr[page->index] |= attr;
716}
717
718static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
719 enum bitmap_page_attr attr)
720{
721 bitmap->filemap_attr[page->index] &= ~attr;
722}
723
724static inline unsigned long get_page_attr(struct bitmap *bitmap, struct page *page)
725{
726 return bitmap->filemap_attr[page->index];
727}
728
729/*
730 * bitmap_file_set_bit -- called before performing a write to the md device
731 * to set (and eventually sync) a particular bit in the bitmap file
732 *
733 * we set the bit immediately, then we record the page number so that
734 * when an unplug occurs, we can flush the dirty pages out to disk
735 */
736static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
737{
738 unsigned long bit;
739 struct page *page;
740 void *kaddr;
741 unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
742
743 if (!bitmap->filemap) {
744 return;
745 }
746
747 page = filemap_get_page(bitmap, chunk);
748 bit = file_page_offset(chunk);
749
750
751 /* make sure the page stays cached until it gets written out */
752 if (! (get_page_attr(bitmap, page) & BITMAP_PAGE_DIRTY))
753 page_cache_get(page);
754
755 /* set the bit */
756 kaddr = kmap_atomic(page, KM_USER0);
757 set_bit(bit, kaddr);
758 kunmap_atomic(kaddr, KM_USER0);
759 PRINTK("set file bit %lu page %lu\n", bit, page->index);
760
761 /* record page number so it gets flushed to disk when unplug occurs */
762 set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
763
764}
765
766/* this gets called when the md device is ready to unplug its underlying
767 * (slave) device queues -- before we let any writes go down, we need to
768 * sync the dirty pages of the bitmap file to disk */
769int bitmap_unplug(struct bitmap *bitmap)
770{
771 unsigned long i, attr, flags;
772 struct page *page;
773 int wait = 0;
774 int err;
775
776 if (!bitmap)
777 return 0;
778
779 /* look at each page to see if there are any set bits that need to be
780 * flushed out to disk */
781 for (i = 0; i < bitmap->file_pages; i++) {
782 spin_lock_irqsave(&bitmap->lock, flags);
783 if (!bitmap->filemap) {
784 spin_unlock_irqrestore(&bitmap->lock, flags);
785 return 0;
786 }
787 page = bitmap->filemap[i];
788 attr = get_page_attr(bitmap, page);
789 clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
790 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
791 if ((attr & BITMAP_PAGE_DIRTY))
792 wait = 1;
793 spin_unlock_irqrestore(&bitmap->lock, flags);
794
795 if (attr & (BITMAP_PAGE_DIRTY | BITMAP_PAGE_NEEDWRITE)) {
796 err = write_page(bitmap, page, 0);
797 if (err == -EAGAIN) {
798 if (attr & BITMAP_PAGE_DIRTY)
799 err = write_page(bitmap, page, 1);
800 else
801 err = 0;
802 }
803 if (err)
804 return 1;
805 }
806 }
807 if (wait) { /* if any writes were performed, we need to wait on them */
808 if (bitmap->file) {
809 spin_lock_irq(&bitmap->write_lock);
810 wait_event_lock_irq(bitmap->write_wait,
811 list_empty(&bitmap->complete_pages), bitmap->write_lock,
812 wake_up_process(bitmap->writeback_daemon->tsk));
813 spin_unlock_irq(&bitmap->write_lock);
814 } else
815 wait_event(bitmap->mddev->sb_wait,
816 atomic_read(&bitmap->mddev->pending_writes)==0);
817 }
818 return 0;
819}
820
821static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset,
822 unsigned long sectors, int in_sync);
823/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
824 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
825 * memory mapping of the bitmap file
826 * Special cases:
827 * if there's no bitmap file, or if the bitmap file had been
828 * previously kicked from the array, we mark all the bits as
829 * 1's in order to cause a full resync.
830 */
831static int bitmap_init_from_disk(struct bitmap *bitmap, int in_sync)
832{
833 unsigned long i, chunks, index, oldindex, bit;
834 struct page *page = NULL, *oldpage = NULL;
835 unsigned long num_pages, bit_cnt = 0;
836 struct file *file;
837 unsigned long bytes, offset, dummy;
838 int outofdate;
839 int ret = -ENOSPC;
840
841 chunks = bitmap->chunks;
842 file = bitmap->file;
843
844 BUG_ON(!file && !bitmap->offset);
845
846#if INJECT_FAULTS_3
847 outofdate = 1;
848#else
849 outofdate = bitmap->flags & BITMAP_STALE;
850#endif
851 if (outofdate)
852 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
853 "recovery\n", bmname(bitmap));
854
855 bytes = (chunks + 7) / 8;
856
857 num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE;
858
859 if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
860 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
861 bmname(bitmap),
862 (unsigned long) i_size_read(file->f_mapping->host),
863 bytes + sizeof(bitmap_super_t));
864 goto out;
865 }
866
867 ret = -ENOMEM;
868
869 bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
870 if (!bitmap->filemap)
871 goto out;
872
873 bitmap->filemap_attr = kmalloc(sizeof(long) * num_pages, GFP_KERNEL);
874 if (!bitmap->filemap_attr)
875 goto out;
876
877 memset(bitmap->filemap_attr, 0, sizeof(long) * num_pages);
878
879 oldindex = ~0L;
880
881 for (i = 0; i < chunks; i++) {
882 index = file_page_index(i);
883 bit = file_page_offset(i);
884 if (index != oldindex) { /* this is a new page, read it in */
885 /* unmap the old page, we're done with it */
886 if (oldpage != NULL)
887 kunmap(oldpage);
888 if (index == 0) {
889 /*
890 * if we're here then the superblock page
891 * contains some bits (PAGE_SIZE != sizeof sb)
892 * we've already read it in, so just use it
893 */
894 page = bitmap->sb_page;
895 offset = sizeof(bitmap_super_t);
896 } else if (file) {
897 page = read_page(file, index, &dummy);
898 offset = 0;
899 } else {
900 page = read_sb_page(bitmap->mddev, bitmap->offset, index);
901 offset = 0;
902 }
903 if (IS_ERR(page)) { /* read error */
904 ret = PTR_ERR(page);
905 goto out;
906 }
907
908 oldindex = index;
909 oldpage = page;
910 kmap(page);
911
912 if (outofdate) {
913 /*
914 * if bitmap is out of date, dirty the
915 * whole page and write it out
916 */
917 memset(page_address(page) + offset, 0xff,
918 PAGE_SIZE - offset);
919 ret = write_page(bitmap, page, 1);
920 if (ret) {
921 kunmap(page);
922 /* release, page not in filemap yet */
923 page_cache_release(page);
924 goto out;
925 }
926 }
927
928 bitmap->filemap[bitmap->file_pages++] = page;
929 }
930 if (test_bit(bit, page_address(page))) {
931 /* if the disk bit is set, set the memory bit */
932 bitmap_set_memory_bits(bitmap,
933 i << CHUNK_BLOCK_SHIFT(bitmap), 1, in_sync);
934 bit_cnt++;
935 }
936 }
937
938 /* everything went OK */
939 ret = 0;
940 bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
941
942 if (page) /* unmap the last page */
943 kunmap(page);
944
945 if (bit_cnt) { /* Kick recovery if any bits were set */
946 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
947 md_wakeup_thread(bitmap->mddev->thread);
948 }
949
950out:
951 printk(KERN_INFO "%s: bitmap initialized from disk: "
952 "read %lu/%lu pages, set %lu bits, status: %d\n",
953 bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, ret);
954
955 return ret;
956}
957
958void bitmap_write_all(struct bitmap *bitmap)
959{
960 /* We don't actually write all bitmap blocks here,
961 * just flag them as needing to be written
962 */
963
964 unsigned long chunks = bitmap->chunks;
965 unsigned long bytes = (chunks+7)/8 + sizeof(bitmap_super_t);
966 unsigned long num_pages = (bytes + PAGE_SIZE-1) / PAGE_SIZE;
967 while (num_pages--)
968 bitmap->filemap_attr[num_pages] |= BITMAP_PAGE_NEEDWRITE;
969}
970
971
972static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
973{
974 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
975 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
976 bitmap->bp[page].count += inc;
977/*
978 if (page == 0) printk("count page 0, offset %llu: %d gives %d\n",
979 (unsigned long long)offset, inc, bitmap->bp[page].count);
980*/
981 bitmap_checkfree(bitmap, page);
982}
983static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
984 sector_t offset, int *blocks,
985 int create);
986
987/*
988 * bitmap daemon -- periodically wakes up to clean bits and flush pages
989 * out to disk
990 */
991
992int bitmap_daemon_work(struct bitmap *bitmap)
993{
994 unsigned long j;
995 unsigned long flags;
996 struct page *page = NULL, *lastpage = NULL;
997 int err = 0;
998 int blocks;
999 int attr;
1000
1001 if (bitmap == NULL)
1002 return 0;
1003 if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ))
1004 return 0;
1005 bitmap->daemon_lastrun = jiffies;
1006
1007 for (j = 0; j < bitmap->chunks; j++) {
1008 bitmap_counter_t *bmc;
1009 spin_lock_irqsave(&bitmap->lock, flags);
1010 if (!bitmap->filemap) {
1011 /* error or shutdown */
1012 spin_unlock_irqrestore(&bitmap->lock, flags);
1013 break;
1014 }
1015
1016 page = filemap_get_page(bitmap, j);
1017
1018 if (page != lastpage) {
1019 /* skip this page unless it's marked as needing cleaning */
1020 if (!((attr=get_page_attr(bitmap, page)) & BITMAP_PAGE_CLEAN)) {
1021 if (attr & BITMAP_PAGE_NEEDWRITE) {
1022 page_cache_get(page);
1023 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1024 }
1025 spin_unlock_irqrestore(&bitmap->lock, flags);
1026 if (attr & BITMAP_PAGE_NEEDWRITE) {
1027 switch (write_page(bitmap, page, 0)) {
1028 case -EAGAIN:
1029 set_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1030 break;
1031 case 0:
1032 break;
1033 default:
1034 bitmap_file_kick(bitmap);
1035 }
1036 page_cache_release(page);
1037 }
1038 continue;
1039 }
1040
1041 /* grab the new page, sync and release the old */
1042 page_cache_get(page);
1043 if (lastpage != NULL) {
1044 if (get_page_attr(bitmap, lastpage) & BITMAP_PAGE_NEEDWRITE) {
1045 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1046 spin_unlock_irqrestore(&bitmap->lock, flags);
1047 err = write_page(bitmap, lastpage, 0);
1048 if (err == -EAGAIN) {
1049 err = 0;
1050 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1051 }
1052 } else {
1053 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1054 spin_unlock_irqrestore(&bitmap->lock, flags);
1055 }
1056 kunmap(lastpage);
1057 page_cache_release(lastpage);
1058 if (err)
1059 bitmap_file_kick(bitmap);
1060 } else
1061 spin_unlock_irqrestore(&bitmap->lock, flags);
1062 lastpage = page;
1063 kmap(page);
1064/*
1065 printk("bitmap clean at page %lu\n", j);
1066*/
1067 spin_lock_irqsave(&bitmap->lock, flags);
1068 clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1069 }
1070 bmc = bitmap_get_counter(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1071 &blocks, 0);
1072 if (bmc) {
1073/*
1074 if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc);
1075*/
1076 if (*bmc == 2) {
1077 *bmc=1; /* maybe clear the bit next time */
1078 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1079 } else if (*bmc == 1) {
1080 /* we can clear the bit */
1081 *bmc = 0;
1082 bitmap_count_page(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1083 -1);
1084
1085 /* clear the bit */
1086 clear_bit(file_page_offset(j), page_address(page));
1087 }
1088 }
1089 spin_unlock_irqrestore(&bitmap->lock, flags);
1090 }
1091
1092 /* now sync the final page */
1093 if (lastpage != NULL) {
1094 kunmap(lastpage);
1095 spin_lock_irqsave(&bitmap->lock, flags);
1096 if (get_page_attr(bitmap, lastpage) &BITMAP_PAGE_NEEDWRITE) {
1097 clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1098 spin_unlock_irqrestore(&bitmap->lock, flags);
1099 err = write_page(bitmap, lastpage, 0);
1100 if (err == -EAGAIN) {
1101 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1102 err = 0;
1103 }
1104 } else {
1105 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1106 spin_unlock_irqrestore(&bitmap->lock, flags);
1107 }
1108
1109 page_cache_release(lastpage);
1110 }
1111
1112 return err;
1113}
1114
1115static void daemon_exit(struct bitmap *bitmap, mdk_thread_t **daemon)
1116{
1117 mdk_thread_t *dmn;
1118 unsigned long flags;
1119
1120 /* if no one is waiting on us, we'll free the md thread struct
1121 * and exit, otherwise we let the waiter clean things up */
1122 spin_lock_irqsave(&bitmap->lock, flags);
1123 if ((dmn = *daemon)) { /* no one is waiting, cleanup and exit */
1124 *daemon = NULL;
1125 spin_unlock_irqrestore(&bitmap->lock, flags);
1126 kfree(dmn);
1127 complete_and_exit(NULL, 0); /* do_exit not exported */
1128 }
1129 spin_unlock_irqrestore(&bitmap->lock, flags);
1130}
1131
1132static void bitmap_writeback_daemon(mddev_t *mddev)
1133{
1134 struct bitmap *bitmap = mddev->bitmap;
1135 struct page *page;
1136 struct page_list *item;
1137 int err = 0;
1138
1139 if (signal_pending(current)) {
1140 printk(KERN_INFO
1141 "%s: bitmap writeback daemon got signal, exiting...\n",
1142 bmname(bitmap));
1143 err = -EINTR;
1144 goto out;
1145 }
1146
1147 PRINTK("%s: bitmap writeback daemon woke up...\n", bmname(bitmap));
1148 /* wait on bitmap page writebacks */
1149 while ((item = dequeue_page(bitmap))) {
1150 page = item->page;
1151 mempool_free(item, bitmap->write_pool);
1152 PRINTK("wait on page writeback: %p\n", page);
1153 wait_on_page_writeback(page);
1154 PRINTK("finished page writeback: %p\n", page);
1155
1156 err = PageError(page);
1157 page_cache_release(page);
1158 if (err) {
1159 printk(KERN_WARNING "%s: bitmap file writeback "
1160 "failed (page %lu): %d\n",
1161 bmname(bitmap), page->index, err);
1162 bitmap_file_kick(bitmap);
1163 goto out;
1164 }
1165 }
1166 out:
1167 wake_up(&bitmap->write_wait);
1168 if (err) {
1169 printk(KERN_INFO "%s: bitmap writeback daemon exiting (%d)\n",
1170 bmname(bitmap), err);
1171 daemon_exit(bitmap, &bitmap->writeback_daemon);
1172 }
1173}
1174
1175static int bitmap_start_daemon(struct bitmap *bitmap, mdk_thread_t **ptr,
1176 void (*func)(mddev_t *), char *name)
1177{
1178 mdk_thread_t *daemon;
1179 unsigned long flags;
1180 char namebuf[32];
1181
1182 spin_lock_irqsave(&bitmap->lock, flags);
1183 *ptr = NULL;
1184
1185 if (!bitmap->file) /* no need for daemon if there's no backing file */
1186 goto out_unlock;
1187
1188 spin_unlock_irqrestore(&bitmap->lock, flags);
1189
1190#if INJECT_FATAL_FAULT_2
1191 daemon = NULL;
1192#else
1193 sprintf(namebuf, "%%s_%s", name);
1194 daemon = md_register_thread(func, bitmap->mddev, namebuf);
1195#endif
1196 if (!daemon) {
1197 printk(KERN_ERR "%s: failed to start bitmap daemon\n",
1198 bmname(bitmap));
1199 return -ECHILD;
1200 }
1201
1202 spin_lock_irqsave(&bitmap->lock, flags);
1203 *ptr = daemon;
1204
1205 md_wakeup_thread(daemon); /* start it running */
1206
1207 PRINTK("%s: %s daemon (pid %d) started...\n",
1208 bmname(bitmap), name, daemon->tsk->pid);
1209out_unlock:
1210 spin_unlock_irqrestore(&bitmap->lock, flags);
1211 return 0;
1212}
1213
1214static int bitmap_start_daemons(struct bitmap *bitmap)
1215{
1216 int err = bitmap_start_daemon(bitmap, &bitmap->writeback_daemon,
1217 bitmap_writeback_daemon, "bitmap_wb");
1218 return err;
1219}
1220
1221static void bitmap_stop_daemon(struct bitmap *bitmap, mdk_thread_t **ptr)
1222{
1223 mdk_thread_t *daemon;
1224 unsigned long flags;
1225
1226 spin_lock_irqsave(&bitmap->lock, flags);
1227 daemon = *ptr;
1228 *ptr = NULL;
1229 spin_unlock_irqrestore(&bitmap->lock, flags);
1230 if (daemon)
1231 md_unregister_thread(daemon); /* destroy the thread */
1232}
1233
1234static void bitmap_stop_daemons(struct bitmap *bitmap)
1235{
1236 /* the daemons can't stop themselves... they'll just exit instead... */
1237 if (bitmap->writeback_daemon &&
1238 current->pid != bitmap->writeback_daemon->tsk->pid)
1239 bitmap_stop_daemon(bitmap, &bitmap->writeback_daemon);
1240}
1241
1242static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1243 sector_t offset, int *blocks,
1244 int create)
1245{
1246 /* If 'create', we might release the lock and reclaim it.
1247 * The lock must have been taken with interrupts enabled.
1248 * If !create, we don't release the lock.
1249 */
1250 sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1251 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1252 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1253 sector_t csize;
1254
1255 if (bitmap_checkpage(bitmap, page, create) < 0) {
1256 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1257 *blocks = csize - (offset & (csize- 1));
1258 return NULL;
1259 }
1260 /* now locked ... */
1261
1262 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1263 /* should we use the first or second counter field
1264 * of the hijacked pointer? */
1265 int hi = (pageoff > PAGE_COUNTER_MASK);
1266 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) +
1267 PAGE_COUNTER_SHIFT - 1);
1268 *blocks = csize - (offset & (csize- 1));
1269 return &((bitmap_counter_t *)
1270 &bitmap->bp[page].map)[hi];
1271 } else { /* page is allocated */
1272 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1273 *blocks = csize - (offset & (csize- 1));
1274 return (bitmap_counter_t *)
1275 &(bitmap->bp[page].map[pageoff]);
1276 }
1277}
1278
1279int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors)
1280{
1281 if (!bitmap) return 0;
1282 while (sectors) {
1283 int blocks;
1284 bitmap_counter_t *bmc;
1285
1286 spin_lock_irq(&bitmap->lock);
1287 bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
1288 if (!bmc) {
1289 spin_unlock_irq(&bitmap->lock);
1290 return 0;
1291 }
1292
1293 switch(*bmc) {
1294 case 0:
1295 bitmap_file_set_bit(bitmap, offset);
1296 bitmap_count_page(bitmap,offset, 1);
1297 blk_plug_device(bitmap->mddev->queue);
1298 /* fall through */
1299 case 1:
1300 *bmc = 2;
1301 }
1302 if ((*bmc & COUNTER_MAX) == COUNTER_MAX) BUG();
1303 (*bmc)++;
1304
1305 spin_unlock_irq(&bitmap->lock);
1306
1307 offset += blocks;
1308 if (sectors > blocks)
1309 sectors -= blocks;
1310 else sectors = 0;
1311 }
1312 return 0;
1313}
1314
1315void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1316 int success)
1317{
1318 if (!bitmap) return;
1319 while (sectors) {
1320 int blocks;
1321 unsigned long flags;
1322 bitmap_counter_t *bmc;
1323
1324 spin_lock_irqsave(&bitmap->lock, flags);
1325 bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
1326 if (!bmc) {
1327 spin_unlock_irqrestore(&bitmap->lock, flags);
1328 return;
1329 }
1330
1331 if (!success && ! (*bmc & NEEDED_MASK))
1332 *bmc |= NEEDED_MASK;
1333
1334 (*bmc)--;
1335 if (*bmc <= 2) {
1336 set_page_attr(bitmap,
1337 filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1338 BITMAP_PAGE_CLEAN);
1339 }
1340 spin_unlock_irqrestore(&bitmap->lock, flags);
1341 offset += blocks;
1342 if (sectors > blocks)
1343 sectors -= blocks;
1344 else sectors = 0;
1345 }
1346}
1347
1348int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks)
1349{
1350 bitmap_counter_t *bmc;
1351 int rv;
1352 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1353 *blocks = 1024;
1354 return 1; /* always resync if no bitmap */
1355 }
1356 spin_lock_irq(&bitmap->lock);
1357 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1358 rv = 0;
1359 if (bmc) {
1360 /* locked */
1361 if (RESYNC(*bmc))
1362 rv = 1;
1363 else if (NEEDED(*bmc)) {
1364 rv = 1;
1365 *bmc |= RESYNC_MASK;
1366 *bmc &= ~NEEDED_MASK;
1367 }
1368 }
1369 spin_unlock_irq(&bitmap->lock);
1370 return rv;
1371}
1372
1373void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted)
1374{
1375 bitmap_counter_t *bmc;
1376 unsigned long flags;
1377/*
1378 if (offset == 0) printk("bitmap_end_sync 0 (%d)\n", aborted);
1379*/ if (bitmap == NULL) {
1380 *blocks = 1024;
1381 return;
1382 }
1383 spin_lock_irqsave(&bitmap->lock, flags);
1384 bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1385 if (bmc == NULL)
1386 goto unlock;
1387 /* locked */
1388/*
1389 if (offset == 0) printk("bitmap_end sync found 0x%x, blocks %d\n", *bmc, *blocks);
1390*/
1391 if (RESYNC(*bmc)) {
1392 *bmc &= ~RESYNC_MASK;
1393
1394 if (!NEEDED(*bmc) && aborted)
1395 *bmc |= NEEDED_MASK;
1396 else {
1397 if (*bmc <= 2) {
1398 set_page_attr(bitmap,
1399 filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1400 BITMAP_PAGE_CLEAN);
1401 }
1402 }
1403 }
1404 unlock:
1405 spin_unlock_irqrestore(&bitmap->lock, flags);
1406}
1407
1408void bitmap_close_sync(struct bitmap *bitmap)
1409{
1410 /* Sync has finished, and any bitmap chunks that weren't synced
1411 * properly have been aborted. It remains to us to clear the
1412 * RESYNC bit wherever it is still on
1413 */
1414 sector_t sector = 0;
1415 int blocks;
1416 if (!bitmap) return;
1417 while (sector < bitmap->mddev->resync_max_sectors) {
1418 bitmap_end_sync(bitmap, sector, &blocks, 0);
1419/*
1420 if (sector < 500) printk("bitmap_close_sync: sec %llu blks %d\n",
1421 (unsigned long long)sector, blocks);
1422*/ sector += blocks;
1423 }
1424}
1425
1426static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset,
1427 unsigned long sectors, int in_sync)
1428{
1429 /* For each chunk covered by any of these sectors, set the
1430 * counter to 1 and set resync_needed unless in_sync. They should all
1431 * be 0 at this point
1432 */
1433 while (sectors) {
1434 int secs;
1435 bitmap_counter_t *bmc;
1436 spin_lock_irq(&bitmap->lock);
1437 bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
1438 if (!bmc) {
1439 spin_unlock_irq(&bitmap->lock);
1440 return;
1441 }
1442 if (! *bmc) {
1443 struct page *page;
1444 *bmc = 1 | (in_sync? 0 : NEEDED_MASK);
1445 bitmap_count_page(bitmap, offset, 1);
1446 page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
1447 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1448 }
1449 spin_unlock_irq(&bitmap->lock);
1450 if (sectors > secs)
1451 sectors -= secs;
1452 else
1453 sectors = 0;
1454 }
1455}
1456
1457/*
1458 * free memory that was allocated
1459 */
1460void bitmap_destroy(mddev_t *mddev)
1461{
1462 unsigned long k, pages;
1463 struct bitmap_page *bp;
1464 struct bitmap *bitmap = mddev->bitmap;
1465
1466 if (!bitmap) /* there was no bitmap */
1467 return;
1468
1469 mddev->bitmap = NULL; /* disconnect from the md device */
1470
1471 /* release the bitmap file and kill the daemon */
1472 bitmap_file_put(bitmap);
1473
1474 bp = bitmap->bp;
1475 pages = bitmap->pages;
1476
1477 /* free all allocated memory */
1478
1479 mempool_destroy(bitmap->write_pool);
1480
1481 if (bp) /* deallocate the page memory */
1482 for (k = 0; k < pages; k++)
1483 if (bp[k].map && !bp[k].hijacked)
1484 kfree(bp[k].map);
1485 kfree(bp);
1486 kfree(bitmap);
1487}
1488
1489/*
1490 * initialize the bitmap structure
1491 * if this returns an error, bitmap_destroy must be called to do clean up
1492 */
1493int bitmap_create(mddev_t *mddev)
1494{
1495 struct bitmap *bitmap;
1496 unsigned long blocks = mddev->resync_max_sectors;
1497 unsigned long chunks;
1498 unsigned long pages;
1499 struct file *file = mddev->bitmap_file;
1500 int err;
1501
1502 BUG_ON(sizeof(bitmap_super_t) != 256);
1503
1504 if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */
1505 return 0;
1506
1507 BUG_ON(file && mddev->bitmap_offset);
1508
1509 bitmap = kmalloc(sizeof(*bitmap), GFP_KERNEL);
1510 if (!bitmap)
1511 return -ENOMEM;
1512
1513 memset(bitmap, 0, sizeof(*bitmap));
1514
1515 spin_lock_init(&bitmap->lock);
1516 bitmap->mddev = mddev;
1517 mddev->bitmap = bitmap;
1518
1519 spin_lock_init(&bitmap->write_lock);
1520 INIT_LIST_HEAD(&bitmap->complete_pages);
1521 init_waitqueue_head(&bitmap->write_wait);
1522 bitmap->write_pool = mempool_create(WRITE_POOL_SIZE, write_pool_alloc,
1523 write_pool_free, NULL);
1524 if (!bitmap->write_pool)
1525 return -ENOMEM;
1526
1527 bitmap->file = file;
1528 bitmap->offset = mddev->bitmap_offset;
1529 if (file) get_file(file);
1530 /* read superblock from bitmap file (this sets bitmap->chunksize) */
1531 err = bitmap_read_sb(bitmap);
1532 if (err)
1533 return err;
1534
1535 bitmap->chunkshift = find_first_bit(&bitmap->chunksize,
1536 sizeof(bitmap->chunksize));
1537
1538 /* now that chunksize and chunkshift are set, we can use these macros */
1539 chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) /
1540 CHUNK_BLOCK_RATIO(bitmap);
1541 pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1542
1543 BUG_ON(!pages);
1544
1545 bitmap->chunks = chunks;
1546 bitmap->pages = pages;
1547 bitmap->missing_pages = pages;
1548 bitmap->counter_bits = COUNTER_BITS;
1549
1550 bitmap->syncchunk = ~0UL;
1551
1552#if INJECT_FATAL_FAULT_1
1553 bitmap->bp = NULL;
1554#else
1555 bitmap->bp = kmalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1556#endif
1557 if (!bitmap->bp)
1558 return -ENOMEM;
1559 memset(bitmap->bp, 0, pages * sizeof(*bitmap->bp));
1560
1561 bitmap->flags |= BITMAP_ACTIVE;
1562
1563 /* now that we have some pages available, initialize the in-memory
1564 * bitmap from the on-disk bitmap */
1565 err = bitmap_init_from_disk(bitmap, mddev->recovery_cp == MaxSector);
1566 if (err)
1567 return err;
1568
1569 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1570 pages, bmname(bitmap));
1571
1572 /* kick off the bitmap daemons */
1573 err = bitmap_start_daemons(bitmap);
1574 if (err)
1575 return err;
1576 return bitmap_update_sb(bitmap);
1577}
1578
1579/* the bitmap API -- for raid personalities */
1580EXPORT_SYMBOL(bitmap_startwrite);
1581EXPORT_SYMBOL(bitmap_endwrite);
1582EXPORT_SYMBOL(bitmap_start_sync);
1583EXPORT_SYMBOL(bitmap_end_sync);
1584EXPORT_SYMBOL(bitmap_unplug);
1585EXPORT_SYMBOL(bitmap_close_sync);
1586EXPORT_SYMBOL(bitmap_daemon_work);
generated by cgit v1.2.2 (git 2.25.0) at 2025-11-03 22:29:23 -0500