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perf bench futex: Cache align the worker struct
[linux/fpc-iii.git] / drivers / md / bitmap.c
blob2d826927a3bf9bd1da8c8f6850fa29e320011908
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 */
17
18 #include <linux/blkdev.h>
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/seq_file.h>
30 #include "md.h"
31 #include "bitmap.h"
32
33 static inline char *bmname(struct bitmap *bitmap)
34 {
35 return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
36 }
37
38 /*
39 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
40 *
41 * 1) check to see if this page is allocated, if it's not then try to alloc
42 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
43 * page pointer directly as a counter
44 *
45 * if we find our page, we increment the page's refcount so that it stays
46 * allocated while we're using it
47 */
48 static int bitmap_checkpage(struct bitmap_counts *bitmap,
49 unsigned long page, int create, int no_hijack)
50 __releases(bitmap->lock)
51 __acquires(bitmap->lock)
52 {
53 unsigned char *mappage;
54
55 if (page >= bitmap->pages) {
56 /* This can happen if bitmap_start_sync goes beyond
57 * End-of-device while looking for a whole page.
58 * It is harmless.
59 */
60 return -EINVAL;
61 }
62
63 if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
64 return 0;
65
66 if (bitmap->bp[page].map) /* page is already allocated, just return */
67 return 0;
68
69 if (!create)
70 return -ENOENT;
71
72 /* this page has not been allocated yet */
73
74 spin_unlock_irq(&bitmap->lock);
75 /* It is possible that this is being called inside a
76 * prepare_to_wait/finish_wait loop from raid5c:make_request().
77 * In general it is not permitted to sleep in that context as it
78 * can cause the loop to spin freely.
79 * That doesn't apply here as we can only reach this point
80 * once with any loop.
81 * When this function completes, either bp[page].map or
82 * bp[page].hijacked. In either case, this function will
83 * abort before getting to this point again. So there is
84 * no risk of a free-spin, and so it is safe to assert
85 * that sleeping here is allowed.
86 */
87 sched_annotate_sleep();
88 mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
89 spin_lock_irq(&bitmap->lock);
90
91 if (mappage == NULL) {
92 pr_debug("md/bitmap: map page allocation failed, hijacking\n");
93 /* We don't support hijack for cluster raid */
94 if (no_hijack)
95 return -ENOMEM;
96 /* failed - set the hijacked flag so that we can use the
97 * pointer as a counter */
98 if (!bitmap->bp[page].map)
99 bitmap->bp[page].hijacked = 1;
100 } else if (bitmap->bp[page].map ||
101 bitmap->bp[page].hijacked) {
102 /* somebody beat us to getting the page */
103 kfree(mappage);
104 } else {
105
106 /* no page was in place and we have one, so install it */
107
108 bitmap->bp[page].map = mappage;
109 bitmap->missing_pages--;
110 }
111 return 0;
112 }
113
114 /* if page is completely empty, put it back on the free list, or dealloc it */
115 /* if page was hijacked, unmark the flag so it might get alloced next time */
116 /* Note: lock should be held when calling this */
117 static void bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
118 {
119 char *ptr;
120
121 if (bitmap->bp[page].count) /* page is still busy */
122 return;
123
124 /* page is no longer in use, it can be released */
125
126 if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
127 bitmap->bp[page].hijacked = 0;
128 bitmap->bp[page].map = NULL;
129 } else {
130 /* normal case, free the page */
131 ptr = bitmap->bp[page].map;
132 bitmap->bp[page].map = NULL;
133 bitmap->missing_pages++;
134 kfree(ptr);
135 }
136 }
137
138 /*
139 * bitmap file handling - read and write the bitmap file and its superblock
140 */
141
142 /*
143 * basic page I/O operations
144 */
145
146 /* IO operations when bitmap is stored near all superblocks */
147 static int read_sb_page(struct mddev *mddev, loff_t offset,
148 struct page *page,
149 unsigned long index, int size)
150 {
151 /* choose a good rdev and read the page from there */
152
153 struct md_rdev *rdev;
154 sector_t target;
155
156 rdev_for_each(rdev, mddev) {
157 if (! test_bit(In_sync, &rdev->flags)
158 || test_bit(Faulty, &rdev->flags))
159 continue;
160
161 target = offset + index * (PAGE_SIZE/512);
162
163 if (sync_page_io(rdev, target,
164 roundup(size, bdev_logical_block_size(rdev->bdev)),
165 page, REQ_OP_READ, 0, true)) {
166 page->index = index;
167 return 0;
168 }
169 }
170 return -EIO;
171 }
172
173 static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
174 {
175 /* Iterate the disks of an mddev, using rcu to protect access to the
176 * linked list, and raising the refcount of devices we return to ensure
177 * they don't disappear while in use.
178 * As devices are only added or removed when raid_disk is < 0 and
179 * nr_pending is 0 and In_sync is clear, the entries we return will
180 * still be in the same position on the list when we re-enter
181 * list_for_each_entry_continue_rcu.
182 *
183 * Note that if entered with 'rdev == NULL' to start at the
184 * beginning, we temporarily assign 'rdev' to an address which
185 * isn't really an rdev, but which can be used by
186 * list_for_each_entry_continue_rcu() to find the first entry.
187 */
188 rcu_read_lock();
189 if (rdev == NULL)
190 /* start at the beginning */
191 rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
192 else {
193 /* release the previous rdev and start from there. */
194 rdev_dec_pending(rdev, mddev);
195 }
196 list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
197 if (rdev->raid_disk >= 0 &&
198 !test_bit(Faulty, &rdev->flags)) {
199 /* this is a usable devices */
200 atomic_inc(&rdev->nr_pending);
201 rcu_read_unlock();
202 return rdev;
203 }
204 }
205 rcu_read_unlock();
206 return NULL;
207 }
208
209 static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
210 {
211 struct md_rdev *rdev = NULL;
212 struct block_device *bdev;
213 struct mddev *mddev = bitmap->mddev;
214 struct bitmap_storage *store = &bitmap->storage;
215
216 while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
217 int size = PAGE_SIZE;
218 loff_t offset = mddev->bitmap_info.offset;
219
220 bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
221
222 if (page->index == store->file_pages-1) {
223 int last_page_size = store->bytes & (PAGE_SIZE-1);
224 if (last_page_size == 0)
225 last_page_size = PAGE_SIZE;
226 size = roundup(last_page_size,
227 bdev_logical_block_size(bdev));
228 }
229 /* Just make sure we aren't corrupting data or
230 * metadata
231 */
232 if (mddev->external) {
233 /* Bitmap could be anywhere. */
234 if (rdev->sb_start + offset + (page->index
235 * (PAGE_SIZE/512))
236 > rdev->data_offset
237 &&
238 rdev->sb_start + offset
239 < (rdev->data_offset + mddev->dev_sectors
240 + (PAGE_SIZE/512)))
241 goto bad_alignment;
242 } else if (offset < 0) {
243 /* DATA BITMAP METADATA */
244 if (offset
245 + (long)(page->index * (PAGE_SIZE/512))
246 + size/512 > 0)
247 /* bitmap runs in to metadata */
248 goto bad_alignment;
249 if (rdev->data_offset + mddev->dev_sectors
250 > rdev->sb_start + offset)
251 /* data runs in to bitmap */
252 goto bad_alignment;
253 } else if (rdev->sb_start < rdev->data_offset) {
254 /* METADATA BITMAP DATA */
255 if (rdev->sb_start
256 + offset
257 + page->index*(PAGE_SIZE/512) + size/512
258 > rdev->data_offset)
259 /* bitmap runs in to data */
260 goto bad_alignment;
261 } else {
262 /* DATA METADATA BITMAP - no problems */
263 }
264 md_super_write(mddev, rdev,
265 rdev->sb_start + offset
266 + page->index * (PAGE_SIZE/512),
267 size,
268 page);
269 }
270
271 if (wait)
272 md_super_wait(mddev);
273 return 0;
274
275 bad_alignment:
276 return -EINVAL;
277 }
278
279 static void bitmap_file_kick(struct bitmap *bitmap);
280 /*
281 * write out a page to a file
282 */
283 static void write_page(struct bitmap *bitmap, struct page *page, int wait)
284 {
285 struct buffer_head *bh;
286
287 if (bitmap->storage.file == NULL) {
288 switch (write_sb_page(bitmap, page, wait)) {
289 case -EINVAL:
290 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
291 }
292 } else {
293
294 bh = page_buffers(page);
295
296 while (bh && bh->b_blocknr) {
297 atomic_inc(&bitmap->pending_writes);
298 set_buffer_locked(bh);
299 set_buffer_mapped(bh);
300 submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
301 bh = bh->b_this_page;
302 }
303
304 if (wait)
305 wait_event(bitmap->write_wait,
306 atomic_read(&bitmap->pending_writes)==0);
307 }
308 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
309 bitmap_file_kick(bitmap);
310 }
311
312 static void end_bitmap_write(struct buffer_head *bh, int uptodate)
313 {
314 struct bitmap *bitmap = bh->b_private;
315
316 if (!uptodate)
317 set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
318 if (atomic_dec_and_test(&bitmap->pending_writes))
319 wake_up(&bitmap->write_wait);
320 }
321
322 /* copied from buffer.c */
323 static void
324 __clear_page_buffers(struct page *page)
325 {
326 ClearPagePrivate(page);
327 set_page_private(page, 0);
328 put_page(page);
329 }
330 static void free_buffers(struct page *page)
331 {
332 struct buffer_head *bh;
333
334 if (!PagePrivate(page))
335 return;
336
337 bh = page_buffers(page);
338 while (bh) {
339 struct buffer_head *next = bh->b_this_page;
340 free_buffer_head(bh);
341 bh = next;
342 }
343 __clear_page_buffers(page);
344 put_page(page);
345 }
346
347 /* read a page from a file.
348 * We both read the page, and attach buffers to the page to record the
349 * address of each block (using bmap). These addresses will be used
350 * to write the block later, completely bypassing the filesystem.
351 * This usage is similar to how swap files are handled, and allows us
352 * to write to a file with no concerns of memory allocation failing.
353 */
354 static int read_page(struct file *file, unsigned long index,
355 struct bitmap *bitmap,
356 unsigned long count,
357 struct page *page)
358 {
359 int ret = 0;
360 struct inode *inode = file_inode(file);
361 struct buffer_head *bh;
362 sector_t block;
363
364 pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
365 (unsigned long long)index << PAGE_SHIFT);
366
367 bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
368 if (!bh) {
369 ret = -ENOMEM;
370 goto out;
371 }
372 attach_page_buffers(page, bh);
373 block = index << (PAGE_SHIFT - inode->i_blkbits);
374 while (bh) {
375 if (count == 0)
376 bh->b_blocknr = 0;
377 else {
378 bh->b_blocknr = bmap(inode, block);
379 if (bh->b_blocknr == 0) {
380 /* Cannot use this file! */
381 ret = -EINVAL;
382 goto out;
383 }
384 bh->b_bdev = inode->i_sb->s_bdev;
385 if (count < (1<<inode->i_blkbits))
386 count = 0;
387 else
388 count -= (1<<inode->i_blkbits);
389
390 bh->b_end_io = end_bitmap_write;
391 bh->b_private = bitmap;
392 atomic_inc(&bitmap->pending_writes);
393 set_buffer_locked(bh);
394 set_buffer_mapped(bh);
395 submit_bh(REQ_OP_READ, 0, bh);
396 }
397 block++;
398 bh = bh->b_this_page;
399 }
400 page->index = index;
401
402 wait_event(bitmap->write_wait,
403 atomic_read(&bitmap->pending_writes)==0);
404 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
405 ret = -EIO;
406 out:
407 if (ret)
408 printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %d\n",
409 (int)PAGE_SIZE,
410 (unsigned long long)index << PAGE_SHIFT,
411 ret);
412 return ret;
413 }
414
415 /*
416 * bitmap file superblock operations
417 */
418
419 /* update the event counter and sync the superblock to disk */
420 void bitmap_update_sb(struct bitmap *bitmap)
421 {
422 bitmap_super_t *sb;
423
424 if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
425 return;
426 if (bitmap->mddev->bitmap_info.external)
427 return;
428 if (!bitmap->storage.sb_page) /* no superblock */
429 return;
430 sb = kmap_atomic(bitmap->storage.sb_page);
431 sb->events = cpu_to_le64(bitmap->mddev->events);
432 if (bitmap->mddev->events < bitmap->events_cleared)
433 /* rocking back to read-only */
434 bitmap->events_cleared = bitmap->mddev->events;
435 sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
436 sb->state = cpu_to_le32(bitmap->flags);
437 /* Just in case these have been changed via sysfs: */
438 sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
439 sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
440 /* This might have been changed by a reshape */
441 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
442 sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
443 sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
444 sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
445 bitmap_info.space);
446 kunmap_atomic(sb);
447 write_page(bitmap, bitmap->storage.sb_page, 1);
448 }
449
450 /* print out the bitmap file superblock */
451 void bitmap_print_sb(struct bitmap *bitmap)
452 {
453 bitmap_super_t *sb;
454
455 if (!bitmap || !bitmap->storage.sb_page)
456 return;
457 sb = kmap_atomic(bitmap->storage.sb_page);
458 printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
459 printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
460 printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
461 printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
462 *(__u32 *)(sb->uuid+0),
463 *(__u32 *)(sb->uuid+4),
464 *(__u32 *)(sb->uuid+8),
465 *(__u32 *)(sb->uuid+12));
466 printk(KERN_DEBUG " events: %llu\n",
467 (unsigned long long) le64_to_cpu(sb->events));
468 printk(KERN_DEBUG "events cleared: %llu\n",
469 (unsigned long long) le64_to_cpu(sb->events_cleared));
470 printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
471 printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
472 printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
473 printk(KERN_DEBUG " sync size: %llu KB\n",
474 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
475 printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
476 kunmap_atomic(sb);
477 }
478
479 /*
480 * bitmap_new_disk_sb
481 * @bitmap
482 *
483 * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
484 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
485 * This function verifies 'bitmap_info' and populates the on-disk bitmap
486 * structure, which is to be written to disk.
487 *
488 * Returns: 0 on success, -Exxx on error
489 */
490 static int bitmap_new_disk_sb(struct bitmap *bitmap)
491 {
492 bitmap_super_t *sb;
493 unsigned long chunksize, daemon_sleep, write_behind;
494
495 bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
496 if (bitmap->storage.sb_page == NULL)
497 return -ENOMEM;
498 bitmap->storage.sb_page->index = 0;
499
500 sb = kmap_atomic(bitmap->storage.sb_page);
501
502 sb->magic = cpu_to_le32(BITMAP_MAGIC);
503 sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
504
505 chunksize = bitmap->mddev->bitmap_info.chunksize;
506 BUG_ON(!chunksize);
507 if (!is_power_of_2(chunksize)) {
508 kunmap_atomic(sb);
509 printk(KERN_ERR "bitmap chunksize not a power of 2\n");
510 return -EINVAL;
511 }
512 sb->chunksize = cpu_to_le32(chunksize);
513
514 daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
515 if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
516 printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
517 daemon_sleep = 5 * HZ;
518 }
519 sb->daemon_sleep = cpu_to_le32(daemon_sleep);
520 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
521
522 /*
523 * FIXME: write_behind for RAID1. If not specified, what
524 * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
525 */
526 write_behind = bitmap->mddev->bitmap_info.max_write_behind;
527 if (write_behind > COUNTER_MAX)
528 write_behind = COUNTER_MAX / 2;
529 sb->write_behind = cpu_to_le32(write_behind);
530 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
531
532 /* keep the array size field of the bitmap superblock up to date */
533 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
534
535 memcpy(sb->uuid, bitmap->mddev->uuid, 16);
536
537 set_bit(BITMAP_STALE, &bitmap->flags);
538 sb->state = cpu_to_le32(bitmap->flags);
539 bitmap->events_cleared = bitmap->mddev->events;
540 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
541 bitmap->mddev->bitmap_info.nodes = 0;
542
543 kunmap_atomic(sb);
544
545 return 0;
546 }
547
548 /* read the superblock from the bitmap file and initialize some bitmap fields */
549 static int bitmap_read_sb(struct bitmap *bitmap)
550 {
551 char *reason = NULL;
552 bitmap_super_t *sb;
553 unsigned long chunksize, daemon_sleep, write_behind;
554 unsigned long long events;
555 int nodes = 0;
556 unsigned long sectors_reserved = 0;
557 int err = -EINVAL;
558 struct page *sb_page;
559 loff_t offset = bitmap->mddev->bitmap_info.offset;
560
561 if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
562 chunksize = 128 * 1024 * 1024;
563 daemon_sleep = 5 * HZ;
564 write_behind = 0;
565 set_bit(BITMAP_STALE, &bitmap->flags);
566 err = 0;
567 goto out_no_sb;
568 }
569 /* page 0 is the superblock, read it... */
570 sb_page = alloc_page(GFP_KERNEL);
571 if (!sb_page)
572 return -ENOMEM;
573 bitmap->storage.sb_page = sb_page;
574
575 re_read:
576 /* If cluster_slot is set, the cluster is setup */
577 if (bitmap->cluster_slot >= 0) {
578 sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
579
580 sector_div(bm_blocks,
581 bitmap->mddev->bitmap_info.chunksize >> 9);
582 /* bits to bytes */
583 bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
584 /* to 4k blocks */
585 bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
586 offset = bitmap->mddev->bitmap_info.offset + (bitmap->cluster_slot * (bm_blocks << 3));
587 pr_info("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
588 bitmap->cluster_slot, offset);
589 }
590
591 if (bitmap->storage.file) {
592 loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
593 int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
594
595 err = read_page(bitmap->storage.file, 0,
596 bitmap, bytes, sb_page);
597 } else {
598 err = read_sb_page(bitmap->mddev,
599 offset,
600 sb_page,
601 0, sizeof(bitmap_super_t));
602 }
603 if (err)
604 return err;
605
606 err = -EINVAL;
607 sb = kmap_atomic(sb_page);
608
609 chunksize = le32_to_cpu(sb->chunksize);
610 daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
611 write_behind = le32_to_cpu(sb->write_behind);
612 sectors_reserved = le32_to_cpu(sb->sectors_reserved);
613 /* Setup nodes/clustername only if bitmap version is
614 * cluster-compatible
615 */
616 if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
617 nodes = le32_to_cpu(sb->nodes);
618 strlcpy(bitmap->mddev->bitmap_info.cluster_name,
619 sb->cluster_name, 64);
620 }
621
622 /* verify that the bitmap-specific fields are valid */
623 if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
624 reason = "bad magic";
625 else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
626 le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
627 reason = "unrecognized superblock version";
628 else if (chunksize < 512)
629 reason = "bitmap chunksize too small";
630 else if (!is_power_of_2(chunksize))
631 reason = "bitmap chunksize not a power of 2";
632 else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
633 reason = "daemon sleep period out of range";
634 else if (write_behind > COUNTER_MAX)
635 reason = "write-behind limit out of range (0 - 16383)";
636 if (reason) {
637 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
638 bmname(bitmap), reason);
639 goto out;
640 }
641
642 /* keep the array size field of the bitmap superblock up to date */
643 sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
644
645 if (bitmap->mddev->persistent) {
646 /*
647 * We have a persistent array superblock, so compare the
648 * bitmap's UUID and event counter to the mddev's
649 */
650 if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
651 printk(KERN_INFO
652 "%s: bitmap superblock UUID mismatch\n",
653 bmname(bitmap));
654 goto out;
655 }
656 events = le64_to_cpu(sb->events);
657 if (!nodes && (events < bitmap->mddev->events)) {
658 printk(KERN_INFO
659 "%s: bitmap file is out of date (%llu < %llu) "
660 "-- forcing full recovery\n",
661 bmname(bitmap), events,
662 (unsigned long long) bitmap->mddev->events);
663 set_bit(BITMAP_STALE, &bitmap->flags);
664 }
665 }
666
667 /* assign fields using values from superblock */
668 bitmap->flags |= le32_to_cpu(sb->state);
669 if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
670 set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
671 bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
672 strlcpy(bitmap->mddev->bitmap_info.cluster_name, sb->cluster_name, 64);
673 err = 0;
674
675 out:
676 kunmap_atomic(sb);
677 /* Assiging chunksize is required for "re_read" */
678 bitmap->mddev->bitmap_info.chunksize = chunksize;
679 if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
680 err = md_setup_cluster(bitmap->mddev, nodes);
681 if (err) {
682 pr_err("%s: Could not setup cluster service (%d)\n",
683 bmname(bitmap), err);
684 goto out_no_sb;
685 }
686 bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
687 goto re_read;
688 }
689
690
691 out_no_sb:
692 if (test_bit(BITMAP_STALE, &bitmap->flags))
693 bitmap->events_cleared = bitmap->mddev->events;
694 bitmap->mddev->bitmap_info.chunksize = chunksize;
695 bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
696 bitmap->mddev->bitmap_info.max_write_behind = write_behind;
697 bitmap->mddev->bitmap_info.nodes = nodes;
698 if (bitmap->mddev->bitmap_info.space == 0 ||
699 bitmap->mddev->bitmap_info.space > sectors_reserved)
700 bitmap->mddev->bitmap_info.space = sectors_reserved;
701 if (err) {
702 bitmap_print_sb(bitmap);
703 if (bitmap->cluster_slot < 0)
704 md_cluster_stop(bitmap->mddev);
705 }
706 return err;
707 }
708
709 /*
710 * general bitmap file operations
711 */
712
713 /*
714 * on-disk bitmap:
715 *
716 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
717 * file a page at a time. There's a superblock at the start of the file.
718 */
719 /* calculate the index of the page that contains this bit */
720 static inline unsigned long file_page_index(struct bitmap_storage *store,
721 unsigned long chunk)
722 {
723 if (store->sb_page)
724 chunk += sizeof(bitmap_super_t) << 3;
725 return chunk >> PAGE_BIT_SHIFT;
726 }
727
728 /* calculate the (bit) offset of this bit within a page */
729 static inline unsigned long file_page_offset(struct bitmap_storage *store,
730 unsigned long chunk)
731 {
732 if (store->sb_page)
733 chunk += sizeof(bitmap_super_t) << 3;
734 return chunk & (PAGE_BITS - 1);
735 }
736
737 /*
738 * return a pointer to the page in the filemap that contains the given bit
739 *
740 */
741 static inline struct page *filemap_get_page(struct bitmap_storage *store,
742 unsigned long chunk)
743 {
744 if (file_page_index(store, chunk) >= store->file_pages)
745 return NULL;
746 return store->filemap[file_page_index(store, chunk)];
747 }
748
749 static int bitmap_storage_alloc(struct bitmap_storage *store,
750 unsigned long chunks, int with_super,
751 int slot_number)
752 {
753 int pnum, offset = 0;
754 unsigned long num_pages;
755 unsigned long bytes;
756
757 bytes = DIV_ROUND_UP(chunks, 8);
758 if (with_super)
759 bytes += sizeof(bitmap_super_t);
760
761 num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
762 offset = slot_number * num_pages;
763
764 store->filemap = kmalloc(sizeof(struct page *)
765 * num_pages, GFP_KERNEL);
766 if (!store->filemap)
767 return -ENOMEM;
768
769 if (with_super && !store->sb_page) {
770 store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
771 if (store->sb_page == NULL)
772 return -ENOMEM;
773 }
774
775 pnum = 0;
776 if (store->sb_page) {
777 store->filemap[0] = store->sb_page;
778 pnum = 1;
779 store->sb_page->index = offset;
780 }
781
782 for ( ; pnum < num_pages; pnum++) {
783 store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
784 if (!store->filemap[pnum]) {
785 store->file_pages = pnum;
786 return -ENOMEM;
787 }
788 store->filemap[pnum]->index = pnum + offset;
789 }
790 store->file_pages = pnum;
791
792 /* We need 4 bits per page, rounded up to a multiple
793 * of sizeof(unsigned long) */
794 store->filemap_attr = kzalloc(
795 roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
796 GFP_KERNEL);
797 if (!store->filemap_attr)
798 return -ENOMEM;
799
800 store->bytes = bytes;
801
802 return 0;
803 }
804
805 static void bitmap_file_unmap(struct bitmap_storage *store)
806 {
807 struct page **map, *sb_page;
808 int pages;
809 struct file *file;
810
811 file = store->file;
812 map = store->filemap;
813 pages = store->file_pages;
814 sb_page = store->sb_page;
815
816 while (pages--)
817 if (map[pages] != sb_page) /* 0 is sb_page, release it below */
818 free_buffers(map[pages]);
819 kfree(map);
820 kfree(store->filemap_attr);
821
822 if (sb_page)
823 free_buffers(sb_page);
824
825 if (file) {
826 struct inode *inode = file_inode(file);
827 invalidate_mapping_pages(inode->i_mapping, 0, -1);
828 fput(file);
829 }
830 }
831
832 /*
833 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
834 * then it is no longer reliable, so we stop using it and we mark the file
835 * as failed in the superblock
836 */
837 static void bitmap_file_kick(struct bitmap *bitmap)
838 {
839 char *path, *ptr = NULL;
840
841 if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
842 bitmap_update_sb(bitmap);
843
844 if (bitmap->storage.file) {
845 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
846 if (path)
847 ptr = file_path(bitmap->storage.file,
848 path, PAGE_SIZE);
849
850 printk(KERN_ALERT
851 "%s: kicking failed bitmap file %s from array!\n",
852 bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
853
854 kfree(path);
855 } else
856 printk(KERN_ALERT
857 "%s: disabling internal bitmap due to errors\n",
858 bmname(bitmap));
859 }
860 }
861
862 enum bitmap_page_attr {
863 BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
864 BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
865 * i.e. counter is 1 or 2. */
866 BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
867 };
868
869 static inline void set_page_attr(struct bitmap *bitmap, int pnum,
870 enum bitmap_page_attr attr)
871 {
872 set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
873 }
874
875 static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
876 enum bitmap_page_attr attr)
877 {
878 clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
879 }
880
881 static inline int test_page_attr(struct bitmap *bitmap, int pnum,
882 enum bitmap_page_attr attr)
883 {
884 return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
885 }
886
887 static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
888 enum bitmap_page_attr attr)
889 {
890 return test_and_clear_bit((pnum<<2) + attr,
891 bitmap->storage.filemap_attr);
892 }
893 /*
894 * bitmap_file_set_bit -- called before performing a write to the md device
895 * to set (and eventually sync) a particular bit in the bitmap file
896 *
897 * we set the bit immediately, then we record the page number so that
898 * when an unplug occurs, we can flush the dirty pages out to disk
899 */
900 static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
901 {
902 unsigned long bit;
903 struct page *page;
904 void *kaddr;
905 unsigned long chunk = block >> bitmap->counts.chunkshift;
906 struct bitmap_storage *store = &bitmap->storage;
907 unsigned long node_offset = 0;
908
909 if (mddev_is_clustered(bitmap->mddev))
910 node_offset = bitmap->cluster_slot * store->file_pages;
911
912 page = filemap_get_page(&bitmap->storage, chunk);
913 if (!page)
914 return;
915 bit = file_page_offset(&bitmap->storage, chunk);
916
917 /* set the bit */
918 kaddr = kmap_atomic(page);
919 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
920 set_bit(bit, kaddr);
921 else
922 set_bit_le(bit, kaddr);
923 kunmap_atomic(kaddr);
924 pr_debug("set file bit %lu page %lu\n", bit, page->index);
925 /* record page number so it gets flushed to disk when unplug occurs */
926 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_DIRTY);
927 }
928
929 static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
930 {
931 unsigned long bit;
932 struct page *page;
933 void *paddr;
934 unsigned long chunk = block >> bitmap->counts.chunkshift;
935 struct bitmap_storage *store = &bitmap->storage;
936 unsigned long node_offset = 0;
937
938 if (mddev_is_clustered(bitmap->mddev))
939 node_offset = bitmap->cluster_slot * store->file_pages;
940
941 page = filemap_get_page(&bitmap->storage, chunk);
942 if (!page)
943 return;
944 bit = file_page_offset(&bitmap->storage, chunk);
945 paddr = kmap_atomic(page);
946 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
947 clear_bit(bit, paddr);
948 else
949 clear_bit_le(bit, paddr);
950 kunmap_atomic(paddr);
951 if (!test_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
952 set_page_attr(bitmap, page->index - node_offset, BITMAP_PAGE_PENDING);
953 bitmap->allclean = 0;
954 }
955 }
956
957 static int bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
958 {
959 unsigned long bit;
960 struct page *page;
961 void *paddr;
962 unsigned long chunk = block >> bitmap->counts.chunkshift;
963 int set = 0;
964
965 page = filemap_get_page(&bitmap->storage, chunk);
966 if (!page)
967 return -EINVAL;
968 bit = file_page_offset(&bitmap->storage, chunk);
969 paddr = kmap_atomic(page);
970 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
971 set = test_bit(bit, paddr);
972 else
973 set = test_bit_le(bit, paddr);
974 kunmap_atomic(paddr);
975 return set;
976 }
977
978
979 /* this gets called when the md device is ready to unplug its underlying
980 * (slave) device queues -- before we let any writes go down, we need to
981 * sync the dirty pages of the bitmap file to disk */
982 void bitmap_unplug(struct bitmap *bitmap)
983 {
984 unsigned long i;
985 int dirty, need_write;
986
987 if (!bitmap || !bitmap->storage.filemap ||
988 test_bit(BITMAP_STALE, &bitmap->flags))
989 return;
990
991 /* look at each page to see if there are any set bits that need to be
992 * flushed out to disk */
993 for (i = 0; i < bitmap->storage.file_pages; i++) {
994 if (!bitmap->storage.filemap)
995 return;
996 dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
997 need_write = test_and_clear_page_attr(bitmap, i,
998 BITMAP_PAGE_NEEDWRITE);
999 if (dirty || need_write) {
1000 clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
1001 write_page(bitmap, bitmap->storage.filemap[i], 0);
1002 }
1003 }
1004 if (bitmap->storage.file)
1005 wait_event(bitmap->write_wait,
1006 atomic_read(&bitmap->pending_writes)==0);
1007 else
1008 md_super_wait(bitmap->mddev);
1009
1010 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1011 bitmap_file_kick(bitmap);
1012 }
1013 EXPORT_SYMBOL(bitmap_unplug);
1014
1015 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
1016 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
1017 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
1018 * memory mapping of the bitmap file
1019 * Special cases:
1020 * if there's no bitmap file, or if the bitmap file had been
1021 * previously kicked from the array, we mark all the bits as
1022 * 1's in order to cause a full resync.
1023 *
1024 * We ignore all bits for sectors that end earlier than 'start'.
1025 * This is used when reading an out-of-date bitmap...
1026 */
1027 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
1028 {
1029 unsigned long i, chunks, index, oldindex, bit, node_offset = 0;
1030 struct page *page = NULL;
1031 unsigned long bit_cnt = 0;
1032 struct file *file;
1033 unsigned long offset;
1034 int outofdate;
1035 int ret = -ENOSPC;
1036 void *paddr;
1037 struct bitmap_storage *store = &bitmap->storage;
1038
1039 chunks = bitmap->counts.chunks;
1040 file = store->file;
1041
1042 if (!file && !bitmap->mddev->bitmap_info.offset) {
1043 /* No permanent bitmap - fill with '1s'. */
1044 store->filemap = NULL;
1045 store->file_pages = 0;
1046 for (i = 0; i < chunks ; i++) {
1047 /* if the disk bit is set, set the memory bit */
1048 int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
1049 >= start);
1050 bitmap_set_memory_bits(bitmap,
1051 (sector_t)i << bitmap->counts.chunkshift,
1052 needed);
1053 }
1054 return 0;
1055 }
1056
1057 outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
1058 if (outofdate)
1059 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
1060 "recovery\n", bmname(bitmap));
1061
1062 if (file && i_size_read(file->f_mapping->host) < store->bytes) {
1063 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
1064 bmname(bitmap),
1065 (unsigned long) i_size_read(file->f_mapping->host),
1066 store->bytes);
1067 goto err;
1068 }
1069
1070 oldindex = ~0L;
1071 offset = 0;
1072 if (!bitmap->mddev->bitmap_info.external)
1073 offset = sizeof(bitmap_super_t);
1074
1075 if (mddev_is_clustered(bitmap->mddev))
1076 node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
1077
1078 for (i = 0; i < chunks; i++) {
1079 int b;
1080 index = file_page_index(&bitmap->storage, i);
1081 bit = file_page_offset(&bitmap->storage, i);
1082 if (index != oldindex) { /* this is a new page, read it in */
1083 int count;
1084 /* unmap the old page, we're done with it */
1085 if (index == store->file_pages-1)
1086 count = store->bytes - index * PAGE_SIZE;
1087 else
1088 count = PAGE_SIZE;
1089 page = store->filemap[index];
1090 if (file)
1091 ret = read_page(file, index, bitmap,
1092 count, page);
1093 else
1094 ret = read_sb_page(
1095 bitmap->mddev,
1096 bitmap->mddev->bitmap_info.offset,
1097 page,
1098 index + node_offset, count);
1099
1100 if (ret)
1101 goto err;
1102
1103 oldindex = index;
1104
1105 if (outofdate) {
1106 /*
1107 * if bitmap is out of date, dirty the
1108 * whole page and write it out
1109 */
1110 paddr = kmap_atomic(page);
1111 memset(paddr + offset, 0xff,
1112 PAGE_SIZE - offset);
1113 kunmap_atomic(paddr);
1114 write_page(bitmap, page, 1);
1115
1116 ret = -EIO;
1117 if (test_bit(BITMAP_WRITE_ERROR,
1118 &bitmap->flags))
1119 goto err;
1120 }
1121 }
1122 paddr = kmap_atomic(page);
1123 if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1124 b = test_bit(bit, paddr);
1125 else
1126 b = test_bit_le(bit, paddr);
1127 kunmap_atomic(paddr);
1128 if (b) {
1129 /* if the disk bit is set, set the memory bit */
1130 int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
1131 >= start);
1132 bitmap_set_memory_bits(bitmap,
1133 (sector_t)i << bitmap->counts.chunkshift,
1134 needed);
1135 bit_cnt++;
1136 }
1137 offset = 0;
1138 }
1139
1140 printk(KERN_INFO "%s: bitmap initialized from disk: "
1141 "read %lu pages, set %lu of %lu bits\n",
1142 bmname(bitmap), store->file_pages,
1143 bit_cnt, chunks);
1144
1145 return 0;
1146
1147 err:
1148 printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
1149 bmname(bitmap), ret);
1150 return ret;
1151 }
1152
1153 void bitmap_write_all(struct bitmap *bitmap)
1154 {
1155 /* We don't actually write all bitmap blocks here,
1156 * just flag them as needing to be written
1157 */
1158 int i;
1159
1160 if (!bitmap || !bitmap->storage.filemap)
1161 return;
1162 if (bitmap->storage.file)
1163 /* Only one copy, so nothing needed */
1164 return;
1165
1166 for (i = 0; i < bitmap->storage.file_pages; i++)
1167 set_page_attr(bitmap, i,
1168 BITMAP_PAGE_NEEDWRITE);
1169 bitmap->allclean = 0;
1170 }
1171
1172 static void bitmap_count_page(struct bitmap_counts *bitmap,
1173 sector_t offset, int inc)
1174 {
1175 sector_t chunk = offset >> bitmap->chunkshift;
1176 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1177 bitmap->bp[page].count += inc;
1178 bitmap_checkfree(bitmap, page);
1179 }
1180
1181 static void bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
1182 {
1183 sector_t chunk = offset >> bitmap->chunkshift;
1184 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1185 struct bitmap_page *bp = &bitmap->bp[page];
1186
1187 if (!bp->pending)
1188 bp->pending = 1;
1189 }
1190
1191 static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
1192 sector_t offset, sector_t *blocks,
1193 int create);
1194
1195 /*
1196 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1197 * out to disk
1198 */
1199
1200 void bitmap_daemon_work(struct mddev *mddev)
1201 {
1202 struct bitmap *bitmap;
1203 unsigned long j;
1204 unsigned long nextpage;
1205 sector_t blocks;
1206 struct bitmap_counts *counts;
1207
1208 /* Use a mutex to guard daemon_work against
1209 * bitmap_destroy.
1210 */
1211 mutex_lock(&mddev->bitmap_info.mutex);
1212 bitmap = mddev->bitmap;
1213 if (bitmap == NULL) {
1214 mutex_unlock(&mddev->bitmap_info.mutex);
1215 return;
1216 }
1217 if (time_before(jiffies, bitmap->daemon_lastrun
1218 + mddev->bitmap_info.daemon_sleep))
1219 goto done;
1220
1221 bitmap->daemon_lastrun = jiffies;
1222 if (bitmap->allclean) {
1223 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1224 goto done;
1225 }
1226 bitmap->allclean = 1;
1227
1228 /* Any file-page which is PENDING now needs to be written.
1229 * So set NEEDWRITE now, then after we make any last-minute changes
1230 * we will write it.
1231 */
1232 for (j = 0; j < bitmap->storage.file_pages; j++)
1233 if (test_and_clear_page_attr(bitmap, j,
1234 BITMAP_PAGE_PENDING))
1235 set_page_attr(bitmap, j,
1236 BITMAP_PAGE_NEEDWRITE);
1237
1238 if (bitmap->need_sync &&
1239 mddev->bitmap_info.external == 0) {
1240 /* Arrange for superblock update as well as
1241 * other changes */
1242 bitmap_super_t *sb;
1243 bitmap->need_sync = 0;
1244 if (bitmap->storage.filemap) {
1245 sb = kmap_atomic(bitmap->storage.sb_page);
1246 sb->events_cleared =
1247 cpu_to_le64(bitmap->events_cleared);
1248 kunmap_atomic(sb);
1249 set_page_attr(bitmap, 0,
1250 BITMAP_PAGE_NEEDWRITE);
1251 }
1252 }
1253 /* Now look at the bitmap counters and if any are '2' or '1',
1254 * decrement and handle accordingly.
1255 */
1256 counts = &bitmap->counts;
1257 spin_lock_irq(&counts->lock);
1258 nextpage = 0;
1259 for (j = 0; j < counts->chunks; j++) {
1260 bitmap_counter_t *bmc;
1261 sector_t block = (sector_t)j << counts->chunkshift;
1262
1263 if (j == nextpage) {
1264 nextpage += PAGE_COUNTER_RATIO;
1265 if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
1266 j |= PAGE_COUNTER_MASK;
1267 continue;
1268 }
1269 counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1270 }
1271 bmc = bitmap_get_counter(counts,
1272 block,
1273 &blocks, 0);
1274
1275 if (!bmc) {
1276 j |= PAGE_COUNTER_MASK;
1277 continue;
1278 }
1279 if (*bmc == 1 && !bitmap->need_sync) {
1280 /* We can clear the bit */
1281 *bmc = 0;
1282 bitmap_count_page(counts, block, -1);
1283 bitmap_file_clear_bit(bitmap, block);
1284 } else if (*bmc && *bmc <= 2) {
1285 *bmc = 1;
1286 bitmap_set_pending(counts, block);
1287 bitmap->allclean = 0;
1288 }
1289 }
1290 spin_unlock_irq(&counts->lock);
1291
1292 /* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
1293 * DIRTY pages need to be written by bitmap_unplug so it can wait
1294 * for them.
1295 * If we find any DIRTY page we stop there and let bitmap_unplug
1296 * handle all the rest. This is important in the case where
1297 * the first blocking holds the superblock and it has been updated.
1298 * We mustn't write any other blocks before the superblock.
1299 */
1300 for (j = 0;
1301 j < bitmap->storage.file_pages
1302 && !test_bit(BITMAP_STALE, &bitmap->flags);
1303 j++) {
1304 if (test_page_attr(bitmap, j,
1305 BITMAP_PAGE_DIRTY))
1306 /* bitmap_unplug will handle the rest */
1307 break;
1308 if (test_and_clear_page_attr(bitmap, j,
1309 BITMAP_PAGE_NEEDWRITE)) {
1310 write_page(bitmap, bitmap->storage.filemap[j], 0);
1311 }
1312 }
1313
1314 done:
1315 if (bitmap->allclean == 0)
1316 mddev->thread->timeout =
1317 mddev->bitmap_info.daemon_sleep;
1318 mutex_unlock(&mddev->bitmap_info.mutex);
1319 }
1320
1321 static bitmap_counter_t *bitmap_get_counter(struct bitmap_counts *bitmap,
1322 sector_t offset, sector_t *blocks,
1323 int create)
1324 __releases(bitmap->lock)
1325 __acquires(bitmap->lock)
1326 {
1327 /* If 'create', we might release the lock and reclaim it.
1328 * The lock must have been taken with interrupts enabled.
1329 * If !create, we don't release the lock.
1330 */
1331 sector_t chunk = offset >> bitmap->chunkshift;
1332 unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1333 unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1334 sector_t csize;
1335 int err;
1336
1337 err = bitmap_checkpage(bitmap, page, create, 0);
1338
1339 if (bitmap->bp[page].hijacked ||
1340 bitmap->bp[page].map == NULL)
1341 csize = ((sector_t)1) << (bitmap->chunkshift +
1342 PAGE_COUNTER_SHIFT - 1);
1343 else
1344 csize = ((sector_t)1) << bitmap->chunkshift;
1345 *blocks = csize - (offset & (csize - 1));
1346
1347 if (err < 0)
1348 return NULL;
1349
1350 /* now locked ... */
1351
1352 if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1353 /* should we use the first or second counter field
1354 * of the hijacked pointer? */
1355 int hi = (pageoff > PAGE_COUNTER_MASK);
1356 return &((bitmap_counter_t *)
1357 &bitmap->bp[page].map)[hi];
1358 } else /* page is allocated */
1359 return (bitmap_counter_t *)
1360 &(bitmap->bp[page].map[pageoff]);
1361 }
1362
1363 int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1364 {
1365 if (!bitmap)
1366 return 0;
1367
1368 if (behind) {
1369 int bw;
1370 atomic_inc(&bitmap->behind_writes);
1371 bw = atomic_read(&bitmap->behind_writes);
1372 if (bw > bitmap->behind_writes_used)
1373 bitmap->behind_writes_used = bw;
1374
1375 pr_debug("inc write-behind count %d/%lu\n",
1376 bw, bitmap->mddev->bitmap_info.max_write_behind);
1377 }
1378
1379 while (sectors) {
1380 sector_t blocks;
1381 bitmap_counter_t *bmc;
1382
1383 spin_lock_irq(&bitmap->counts.lock);
1384 bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
1385 if (!bmc) {
1386 spin_unlock_irq(&bitmap->counts.lock);
1387 return 0;
1388 }
1389
1390 if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1391 DEFINE_WAIT(__wait);
1392 /* note that it is safe to do the prepare_to_wait
1393 * after the test as long as we do it before dropping
1394 * the spinlock.
1395 */
1396 prepare_to_wait(&bitmap->overflow_wait, &__wait,
1397 TASK_UNINTERRUPTIBLE);
1398 spin_unlock_irq(&bitmap->counts.lock);
1399 schedule();
1400 finish_wait(&bitmap->overflow_wait, &__wait);
1401 continue;
1402 }
1403
1404 switch (*bmc) {
1405 case 0:
1406 bitmap_file_set_bit(bitmap, offset);
1407 bitmap_count_page(&bitmap->counts, offset, 1);
1408 /* fall through */
1409 case 1:
1410 *bmc = 2;
1411 }
1412
1413 (*bmc)++;
1414
1415 spin_unlock_irq(&bitmap->counts.lock);
1416
1417 offset += blocks;
1418 if (sectors > blocks)
1419 sectors -= blocks;
1420 else
1421 sectors = 0;
1422 }
1423 return 0;
1424 }
1425 EXPORT_SYMBOL(bitmap_startwrite);
1426
1427 void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1428 int success, int behind)
1429 {
1430 if (!bitmap)
1431 return;
1432 if (behind) {
1433 if (atomic_dec_and_test(&bitmap->behind_writes))
1434 wake_up(&bitmap->behind_wait);
1435 pr_debug("dec write-behind count %d/%lu\n",
1436 atomic_read(&bitmap->behind_writes),
1437 bitmap->mddev->bitmap_info.max_write_behind);
1438 }
1439
1440 while (sectors) {
1441 sector_t blocks;
1442 unsigned long flags;
1443 bitmap_counter_t *bmc;
1444
1445 spin_lock_irqsave(&bitmap->counts.lock, flags);
1446 bmc = bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
1447 if (!bmc) {
1448 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1449 return;
1450 }
1451
1452 if (success && !bitmap->mddev->degraded &&
1453 bitmap->events_cleared < bitmap->mddev->events) {
1454 bitmap->events_cleared = bitmap->mddev->events;
1455 bitmap->need_sync = 1;
1456 sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1457 }
1458
1459 if (!success && !NEEDED(*bmc))
1460 *bmc |= NEEDED_MASK;
1461
1462 if (COUNTER(*bmc) == COUNTER_MAX)
1463 wake_up(&bitmap->overflow_wait);
1464
1465 (*bmc)--;
1466 if (*bmc <= 2) {
1467 bitmap_set_pending(&bitmap->counts, offset);
1468 bitmap->allclean = 0;
1469 }
1470 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1471 offset += blocks;
1472 if (sectors > blocks)
1473 sectors -= blocks;
1474 else
1475 sectors = 0;
1476 }
1477 }
1478 EXPORT_SYMBOL(bitmap_endwrite);
1479
1480 static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1481 int degraded)
1482 {
1483 bitmap_counter_t *bmc;
1484 int rv;
1485 if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1486 *blocks = 1024;
1487 return 1; /* always resync if no bitmap */
1488 }
1489 spin_lock_irq(&bitmap->counts.lock);
1490 bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1491 rv = 0;
1492 if (bmc) {
1493 /* locked */
1494 if (RESYNC(*bmc))
1495 rv = 1;
1496 else if (NEEDED(*bmc)) {
1497 rv = 1;
1498 if (!degraded) { /* don't set/clear bits if degraded */
1499 *bmc |= RESYNC_MASK;
1500 *bmc &= ~NEEDED_MASK;
1501 }
1502 }
1503 }
1504 spin_unlock_irq(&bitmap->counts.lock);
1505 return rv;
1506 }
1507
1508 int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1509 int degraded)
1510 {
1511 /* bitmap_start_sync must always report on multiples of whole
1512 * pages, otherwise resync (which is very PAGE_SIZE based) will
1513 * get confused.
1514 * So call __bitmap_start_sync repeatedly (if needed) until
1515 * At least PAGE_SIZE>>9 blocks are covered.
1516 * Return the 'or' of the result.
1517 */
1518 int rv = 0;
1519 sector_t blocks1;
1520
1521 *blocks = 0;
1522 while (*blocks < (PAGE_SIZE>>9)) {
1523 rv |= __bitmap_start_sync(bitmap, offset,
1524 &blocks1, degraded);
1525 offset += blocks1;
1526 *blocks += blocks1;
1527 }
1528 return rv;
1529 }
1530 EXPORT_SYMBOL(bitmap_start_sync);
1531
1532 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1533 {
1534 bitmap_counter_t *bmc;
1535 unsigned long flags;
1536
1537 if (bitmap == NULL) {
1538 *blocks = 1024;
1539 return;
1540 }
1541 spin_lock_irqsave(&bitmap->counts.lock, flags);
1542 bmc = bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
1543 if (bmc == NULL)
1544 goto unlock;
1545 /* locked */
1546 if (RESYNC(*bmc)) {
1547 *bmc &= ~RESYNC_MASK;
1548
1549 if (!NEEDED(*bmc) && aborted)
1550 *bmc |= NEEDED_MASK;
1551 else {
1552 if (*bmc <= 2) {
1553 bitmap_set_pending(&bitmap->counts, offset);
1554 bitmap->allclean = 0;
1555 }
1556 }
1557 }
1558 unlock:
1559 spin_unlock_irqrestore(&bitmap->counts.lock, flags);
1560 }
1561 EXPORT_SYMBOL(bitmap_end_sync);
1562
1563 void bitmap_close_sync(struct bitmap *bitmap)
1564 {
1565 /* Sync has finished, and any bitmap chunks that weren't synced
1566 * properly have been aborted. It remains to us to clear the
1567 * RESYNC bit wherever it is still on
1568 */
1569 sector_t sector = 0;
1570 sector_t blocks;
1571 if (!bitmap)
1572 return;
1573 while (sector < bitmap->mddev->resync_max_sectors) {
1574 bitmap_end_sync(bitmap, sector, &blocks, 0);
1575 sector += blocks;
1576 }
1577 }
1578 EXPORT_SYMBOL(bitmap_close_sync);
1579
1580 void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
1581 {
1582 sector_t s = 0;
1583 sector_t blocks;
1584
1585 if (!bitmap)
1586 return;
1587 if (sector == 0) {
1588 bitmap->last_end_sync = jiffies;
1589 return;
1590 }
1591 if (!force && time_before(jiffies, (bitmap->last_end_sync
1592 + bitmap->mddev->bitmap_info.daemon_sleep)))
1593 return;
1594 wait_event(bitmap->mddev->recovery_wait,
1595 atomic_read(&bitmap->mddev->recovery_active) == 0);
1596
1597 bitmap->mddev->curr_resync_completed = sector;
1598 set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1599 sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
1600 s = 0;
1601 while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1602 bitmap_end_sync(bitmap, s, &blocks, 0);
1603 s += blocks;
1604 }
1605 bitmap->last_end_sync = jiffies;
1606 sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1607 }
1608 EXPORT_SYMBOL(bitmap_cond_end_sync);
1609
1610 void bitmap_sync_with_cluster(struct mddev *mddev,
1611 sector_t old_lo, sector_t old_hi,
1612 sector_t new_lo, sector_t new_hi)
1613 {
1614 struct bitmap *bitmap = mddev->bitmap;
1615 sector_t sector, blocks = 0;
1616
1617 for (sector = old_lo; sector < new_lo; ) {
1618 bitmap_end_sync(bitmap, sector, &blocks, 0);
1619 sector += blocks;
1620 }
1621 WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
1622
1623 for (sector = old_hi; sector < new_hi; ) {
1624 bitmap_start_sync(bitmap, sector, &blocks, 0);
1625 sector += blocks;
1626 }
1627 WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
1628 }
1629 EXPORT_SYMBOL(bitmap_sync_with_cluster);
1630
1631 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1632 {
1633 /* For each chunk covered by any of these sectors, set the
1634 * counter to 2 and possibly set resync_needed. They should all
1635 * be 0 at this point
1636 */
1637
1638 sector_t secs;
1639 bitmap_counter_t *bmc;
1640 spin_lock_irq(&bitmap->counts.lock);
1641 bmc = bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
1642 if (!bmc) {
1643 spin_unlock_irq(&bitmap->counts.lock);
1644 return;
1645 }
1646 if (!*bmc) {
1647 *bmc = 2;
1648 bitmap_count_page(&bitmap->counts, offset, 1);
1649 bitmap_set_pending(&bitmap->counts, offset);
1650 bitmap->allclean = 0;
1651 }
1652 if (needed)
1653 *bmc |= NEEDED_MASK;
1654 spin_unlock_irq(&bitmap->counts.lock);
1655 }
1656
1657 /* dirty the memory and file bits for bitmap chunks "s" to "e" */
1658 void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1659 {
1660 unsigned long chunk;
1661
1662 for (chunk = s; chunk <= e; chunk++) {
1663 sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
1664 bitmap_set_memory_bits(bitmap, sec, 1);
1665 bitmap_file_set_bit(bitmap, sec);
1666 if (sec < bitmap->mddev->recovery_cp)
1667 /* We are asserting that the array is dirty,
1668 * so move the recovery_cp address back so
1669 * that it is obvious that it is dirty
1670 */
1671 bitmap->mddev->recovery_cp = sec;
1672 }
1673 }
1674
1675 /*
1676 * flush out any pending updates
1677 */
1678 void bitmap_flush(struct mddev *mddev)
1679 {
1680 struct bitmap *bitmap = mddev->bitmap;
1681 long sleep;
1682
1683 if (!bitmap) /* there was no bitmap */
1684 return;
1685
1686 /* run the daemon_work three time to ensure everything is flushed
1687 * that can be
1688 */
1689 sleep = mddev->bitmap_info.daemon_sleep * 2;
1690 bitmap->daemon_lastrun -= sleep;
1691 bitmap_daemon_work(mddev);
1692 bitmap->daemon_lastrun -= sleep;
1693 bitmap_daemon_work(mddev);
1694 bitmap->daemon_lastrun -= sleep;
1695 bitmap_daemon_work(mddev);
1696 bitmap_update_sb(bitmap);
1697 }
1698
1699 /*
1700 * free memory that was allocated
1701 */
1702 static void bitmap_free(struct bitmap *bitmap)
1703 {
1704 unsigned long k, pages;
1705 struct bitmap_page *bp;
1706
1707 if (!bitmap) /* there was no bitmap */
1708 return;
1709
1710 if (bitmap->sysfs_can_clear)
1711 sysfs_put(bitmap->sysfs_can_clear);
1712
1713 if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
1714 bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
1715 md_cluster_stop(bitmap->mddev);
1716
1717 /* Shouldn't be needed - but just in case.... */
1718 wait_event(bitmap->write_wait,
1719 atomic_read(&bitmap->pending_writes) == 0);
1720
1721 /* release the bitmap file */
1722 bitmap_file_unmap(&bitmap->storage);
1723
1724 bp = bitmap->counts.bp;
1725 pages = bitmap->counts.pages;
1726
1727 /* free all allocated memory */
1728
1729 if (bp) /* deallocate the page memory */
1730 for (k = 0; k < pages; k++)
1731 if (bp[k].map && !bp[k].hijacked)
1732 kfree(bp[k].map);
1733 kfree(bp);
1734 kfree(bitmap);
1735 }
1736
1737 void bitmap_destroy(struct mddev *mddev)
1738 {
1739 struct bitmap *bitmap = mddev->bitmap;
1740
1741 if (!bitmap) /* there was no bitmap */
1742 return;
1743
1744 mutex_lock(&mddev->bitmap_info.mutex);
1745 spin_lock(&mddev->lock);
1746 mddev->bitmap = NULL; /* disconnect from the md device */
1747 spin_unlock(&mddev->lock);
1748 mutex_unlock(&mddev->bitmap_info.mutex);
1749 if (mddev->thread)
1750 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1751
1752 bitmap_free(bitmap);
1753 }
1754
1755 /*
1756 * initialize the bitmap structure
1757 * if this returns an error, bitmap_destroy must be called to do clean up
1758 * once mddev->bitmap is set
1759 */
1760 struct bitmap *bitmap_create(struct mddev *mddev, int slot)
1761 {
1762 struct bitmap *bitmap;
1763 sector_t blocks = mddev->resync_max_sectors;
1764 struct file *file = mddev->bitmap_info.file;
1765 int err;
1766 struct kernfs_node *bm = NULL;
1767
1768 BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1769
1770 BUG_ON(file && mddev->bitmap_info.offset);
1771
1772 bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1773 if (!bitmap)
1774 return ERR_PTR(-ENOMEM);
1775
1776 spin_lock_init(&bitmap->counts.lock);
1777 atomic_set(&bitmap->pending_writes, 0);
1778 init_waitqueue_head(&bitmap->write_wait);
1779 init_waitqueue_head(&bitmap->overflow_wait);
1780 init_waitqueue_head(&bitmap->behind_wait);
1781
1782 bitmap->mddev = mddev;
1783 bitmap->cluster_slot = slot;
1784
1785 if (mddev->kobj.sd)
1786 bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
1787 if (bm) {
1788 bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
1789 sysfs_put(bm);
1790 } else
1791 bitmap->sysfs_can_clear = NULL;
1792
1793 bitmap->storage.file = file;
1794 if (file) {
1795 get_file(file);
1796 /* As future accesses to this file will use bmap,
1797 * and bypass the page cache, we must sync the file
1798 * first.
1799 */
1800 vfs_fsync(file, 1);
1801 }
1802 /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1803 if (!mddev->bitmap_info.external) {
1804 /*
1805 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1806 * instructing us to create a new on-disk bitmap instance.
1807 */
1808 if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1809 err = bitmap_new_disk_sb(bitmap);
1810 else
1811 err = bitmap_read_sb(bitmap);
1812 } else {
1813 err = 0;
1814 if (mddev->bitmap_info.chunksize == 0 ||
1815 mddev->bitmap_info.daemon_sleep == 0)
1816 /* chunksize and time_base need to be
1817 * set first. */
1818 err = -EINVAL;
1819 }
1820 if (err)
1821 goto error;
1822
1823 bitmap->daemon_lastrun = jiffies;
1824 err = bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
1825 if (err)
1826 goto error;
1827
1828 printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1829 bitmap->counts.pages, bmname(bitmap));
1830
1831 err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1832 if (err)
1833 goto error;
1834
1835 return bitmap;
1836 error:
1837 bitmap_free(bitmap);
1838 return ERR_PTR(err);
1839 }
1840
1841 int bitmap_load(struct mddev *mddev)
1842 {
1843 int err = 0;
1844 sector_t start = 0;
1845 sector_t sector = 0;
1846 struct bitmap *bitmap = mddev->bitmap;
1847
1848 if (!bitmap)
1849 goto out;
1850
1851 if (mddev_is_clustered(mddev))
1852 md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
1853
1854 /* Clear out old bitmap info first: Either there is none, or we
1855 * are resuming after someone else has possibly changed things,
1856 * so we should forget old cached info.
1857 * All chunks should be clean, but some might need_sync.
1858 */
1859 while (sector < mddev->resync_max_sectors) {
1860 sector_t blocks;
1861 bitmap_start_sync(bitmap, sector, &blocks, 0);
1862 sector += blocks;
1863 }
1864 bitmap_close_sync(bitmap);
1865
1866 if (mddev->degraded == 0
1867 || bitmap->events_cleared == mddev->events)
1868 /* no need to keep dirty bits to optimise a
1869 * re-add of a missing device */
1870 start = mddev->recovery_cp;
1871
1872 mutex_lock(&mddev->bitmap_info.mutex);
1873 err = bitmap_init_from_disk(bitmap, start);
1874 mutex_unlock(&mddev->bitmap_info.mutex);
1875
1876 if (err)
1877 goto out;
1878 clear_bit(BITMAP_STALE, &bitmap->flags);
1879
1880 /* Kick recovery in case any bits were set */
1881 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1882
1883 mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1884 md_wakeup_thread(mddev->thread);
1885
1886 bitmap_update_sb(bitmap);
1887
1888 if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1889 err = -EIO;
1890 out:
1891 return err;
1892 }
1893 EXPORT_SYMBOL_GPL(bitmap_load);
1894
1895 /* Loads the bitmap associated with slot and copies the resync information
1896 * to our bitmap
1897 */
1898 int bitmap_copy_from_slot(struct mddev *mddev, int slot,
1899 sector_t *low, sector_t *high, bool clear_bits)
1900 {
1901 int rv = 0, i, j;
1902 sector_t block, lo = 0, hi = 0;
1903 struct bitmap_counts *counts;
1904 struct bitmap *bitmap = bitmap_create(mddev, slot);
1905
1906 if (IS_ERR(bitmap))
1907 return PTR_ERR(bitmap);
1908
1909 rv = bitmap_init_from_disk(bitmap, 0);
1910 if (rv)
1911 goto err;
1912
1913 counts = &bitmap->counts;
1914 for (j = 0; j < counts->chunks; j++) {
1915 block = (sector_t)j << counts->chunkshift;
1916 if (bitmap_file_test_bit(bitmap, block)) {
1917 if (!lo)
1918 lo = block;
1919 hi = block;
1920 bitmap_file_clear_bit(bitmap, block);
1921 bitmap_set_memory_bits(mddev->bitmap, block, 1);
1922 bitmap_file_set_bit(mddev->bitmap, block);
1923 }
1924 }
1925
1926 if (clear_bits) {
1927 bitmap_update_sb(bitmap);
1928 /* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
1929 * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
1930 for (i = 0; i < bitmap->storage.file_pages; i++)
1931 if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
1932 set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
1933 bitmap_unplug(bitmap);
1934 }
1935 bitmap_unplug(mddev->bitmap);
1936 *low = lo;
1937 *high = hi;
1938 err:
1939 bitmap_free(bitmap);
1940 return rv;
1941 }
1942 EXPORT_SYMBOL_GPL(bitmap_copy_from_slot);
1943
1944
1945 void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
1946 {
1947 unsigned long chunk_kb;
1948 struct bitmap_counts *counts;
1949
1950 if (!bitmap)
1951 return;
1952
1953 counts = &bitmap->counts;
1954
1955 chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
1956 seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
1957 "%lu%s chunk",
1958 counts->pages - counts->missing_pages,
1959 counts->pages,
1960 (counts->pages - counts->missing_pages)
1961 << (PAGE_SHIFT - 10),
1962 chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
1963 chunk_kb ? "KB" : "B");
1964 if (bitmap->storage.file) {
1965 seq_printf(seq, ", file: ");
1966 seq_file_path(seq, bitmap->storage.file, " \t\n");
1967 }
1968
1969 seq_printf(seq, "\n");
1970 }
1971
1972 int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
1973 int chunksize, int init)
1974 {
1975 /* If chunk_size is 0, choose an appropriate chunk size.
1976 * Then possibly allocate new storage space.
1977 * Then quiesce, copy bits, replace bitmap, and re-start
1978 *
1979 * This function is called both to set up the initial bitmap
1980 * and to resize the bitmap while the array is active.
1981 * If this happens as a result of the array being resized,
1982 * chunksize will be zero, and we need to choose a suitable
1983 * chunksize, otherwise we use what we are given.
1984 */
1985 struct bitmap_storage store;
1986 struct bitmap_counts old_counts;
1987 unsigned long chunks;
1988 sector_t block;
1989 sector_t old_blocks, new_blocks;
1990 int chunkshift;
1991 int ret = 0;
1992 long pages;
1993 struct bitmap_page *new_bp;
1994
1995 if (chunksize == 0) {
1996 /* If there is enough space, leave the chunk size unchanged,
1997 * else increase by factor of two until there is enough space.
1998 */
1999 long bytes;
2000 long space = bitmap->mddev->bitmap_info.space;
2001
2002 if (space == 0) {
2003 /* We don't know how much space there is, so limit
2004 * to current size - in sectors.
2005 */
2006 bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
2007 if (!bitmap->mddev->bitmap_info.external)
2008 bytes += sizeof(bitmap_super_t);
2009 space = DIV_ROUND_UP(bytes, 512);
2010 bitmap->mddev->bitmap_info.space = space;
2011 }
2012 chunkshift = bitmap->counts.chunkshift;
2013 chunkshift--;
2014 do {
2015 /* 'chunkshift' is shift from block size to chunk size */
2016 chunkshift++;
2017 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2018 bytes = DIV_ROUND_UP(chunks, 8);
2019 if (!bitmap->mddev->bitmap_info.external)
2020 bytes += sizeof(bitmap_super_t);
2021 } while (bytes > (space << 9));
2022 } else
2023 chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
2024
2025 chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
2026 memset(&store, 0, sizeof(store));
2027 if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
2028 ret = bitmap_storage_alloc(&store, chunks,
2029 !bitmap->mddev->bitmap_info.external,
2030 mddev_is_clustered(bitmap->mddev)
2031 ? bitmap->cluster_slot : 0);
2032 if (ret)
2033 goto err;
2034
2035 pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
2036
2037 new_bp = kzalloc(pages * sizeof(*new_bp), GFP_KERNEL);
2038 ret = -ENOMEM;
2039 if (!new_bp) {
2040 bitmap_file_unmap(&store);
2041 goto err;
2042 }
2043
2044 if (!init)
2045 bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
2046
2047 store.file = bitmap->storage.file;
2048 bitmap->storage.file = NULL;
2049
2050 if (store.sb_page && bitmap->storage.sb_page)
2051 memcpy(page_address(store.sb_page),
2052 page_address(bitmap->storage.sb_page),
2053 sizeof(bitmap_super_t));
2054 bitmap_file_unmap(&bitmap->storage);
2055 bitmap->storage = store;
2056
2057 old_counts = bitmap->counts;
2058 bitmap->counts.bp = new_bp;
2059 bitmap->counts.pages = pages;
2060 bitmap->counts.missing_pages = pages;
2061 bitmap->counts.chunkshift = chunkshift;
2062 bitmap->counts.chunks = chunks;
2063 bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift +
2064 BITMAP_BLOCK_SHIFT);
2065
2066 blocks = min(old_counts.chunks << old_counts.chunkshift,
2067 chunks << chunkshift);
2068
2069 spin_lock_irq(&bitmap->counts.lock);
2070 /* For cluster raid, need to pre-allocate bitmap */
2071 if (mddev_is_clustered(bitmap->mddev)) {
2072 unsigned long page;
2073 for (page = 0; page < pages; page++) {
2074 ret = bitmap_checkpage(&bitmap->counts, page, 1, 1);
2075 if (ret) {
2076 unsigned long k;
2077
2078 /* deallocate the page memory */
2079 for (k = 0; k < page; k++) {
2080 kfree(new_bp[k].map);
2081 }
2082
2083 /* restore some fields from old_counts */
2084 bitmap->counts.bp = old_counts.bp;
2085 bitmap->counts.pages = old_counts.pages;
2086 bitmap->counts.missing_pages = old_counts.pages;
2087 bitmap->counts.chunkshift = old_counts.chunkshift;
2088 bitmap->counts.chunks = old_counts.chunks;
2089 bitmap->mddev->bitmap_info.chunksize = 1 << (old_counts.chunkshift +
2090 BITMAP_BLOCK_SHIFT);
2091 blocks = old_counts.chunks << old_counts.chunkshift;
2092 pr_err("Could not pre-allocate in-memory bitmap for cluster raid\n");
2093 break;
2094 } else
2095 bitmap->counts.bp[page].count += 1;
2096 }
2097 }
2098
2099 for (block = 0; block < blocks; ) {
2100 bitmap_counter_t *bmc_old, *bmc_new;
2101 int set;
2102
2103 bmc_old = bitmap_get_counter(&old_counts, block,
2104 &old_blocks, 0);
2105 set = bmc_old && NEEDED(*bmc_old);
2106
2107 if (set) {
2108 bmc_new = bitmap_get_counter(&bitmap->counts, block,
2109 &new_blocks, 1);
2110 if (*bmc_new == 0) {
2111 /* need to set on-disk bits too. */
2112 sector_t end = block + new_blocks;
2113 sector_t start = block >> chunkshift;
2114 start <<= chunkshift;
2115 while (start < end) {
2116 bitmap_file_set_bit(bitmap, block);
2117 start += 1 << chunkshift;
2118 }
2119 *bmc_new = 2;
2120 bitmap_count_page(&bitmap->counts,
2121 block, 1);
2122 bitmap_set_pending(&bitmap->counts,
2123 block);
2124 }
2125 *bmc_new |= NEEDED_MASK;
2126 if (new_blocks < old_blocks)
2127 old_blocks = new_blocks;
2128 }
2129 block += old_blocks;
2130 }
2131
2132 if (!init) {
2133 int i;
2134 while (block < (chunks << chunkshift)) {
2135 bitmap_counter_t *bmc;
2136 bmc = bitmap_get_counter(&bitmap->counts, block,
2137 &new_blocks, 1);
2138 if (bmc) {
2139 /* new space. It needs to be resynced, so
2140 * we set NEEDED_MASK.
2141 */
2142 if (*bmc == 0) {
2143 *bmc = NEEDED_MASK | 2;
2144 bitmap_count_page(&bitmap->counts,
2145 block, 1);
2146 bitmap_set_pending(&bitmap->counts,
2147 block);
2148 }
2149 }
2150 block += new_blocks;
2151 }
2152 for (i = 0; i < bitmap->storage.file_pages; i++)
2153 set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
2154 }
2155 spin_unlock_irq(&bitmap->counts.lock);
2156
2157 if (!init) {
2158 bitmap_unplug(bitmap);
2159 bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
2160 }
2161 ret = 0;
2162 err:
2163 return ret;
2164 }
2165 EXPORT_SYMBOL_GPL(bitmap_resize);
2166
2167 static ssize_t
2168 location_show(struct mddev *mddev, char *page)
2169 {
2170 ssize_t len;
2171 if (mddev->bitmap_info.file)
2172 len = sprintf(page, "file");
2173 else if (mddev->bitmap_info.offset)
2174 len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
2175 else
2176 len = sprintf(page, "none");
2177 len += sprintf(page+len, "\n");
2178 return len;
2179 }
2180
2181 static ssize_t
2182 location_store(struct mddev *mddev, const char *buf, size_t len)
2183 {
2184 int rv;
2185
2186 rv = mddev_lock(mddev);
2187 if (rv)
2188 return rv;
2189 if (mddev->pers) {
2190 if (!mddev->pers->quiesce) {
2191 rv = -EBUSY;
2192 goto out;
2193 }
2194 if (mddev->recovery || mddev->sync_thread) {
2195 rv = -EBUSY;
2196 goto out;
2197 }
2198 }
2199
2200 if (mddev->bitmap || mddev->bitmap_info.file ||
2201 mddev->bitmap_info.offset) {
2202 /* bitmap already configured. Only option is to clear it */
2203 if (strncmp(buf, "none", 4) != 0) {
2204 rv = -EBUSY;
2205 goto out;
2206 }
2207 if (mddev->pers) {
2208 mddev->pers->quiesce(mddev, 1);
2209 bitmap_destroy(mddev);
2210 mddev->pers->quiesce(mddev, 0);
2211 }
2212 mddev->bitmap_info.offset = 0;
2213 if (mddev->bitmap_info.file) {
2214 struct file *f = mddev->bitmap_info.file;
2215 mddev->bitmap_info.file = NULL;
2216 fput(f);
2217 }
2218 } else {
2219 /* No bitmap, OK to set a location */
2220 long long offset;
2221 if (strncmp(buf, "none", 4) == 0)
2222 /* nothing to be done */;
2223 else if (strncmp(buf, "file:", 5) == 0) {
2224 /* Not supported yet */
2225 rv = -EINVAL;
2226 goto out;
2227 } else {
2228 if (buf[0] == '+')
2229 rv = kstrtoll(buf+1, 10, &offset);
2230 else
2231 rv = kstrtoll(buf, 10, &offset);
2232 if (rv)
2233 goto out;
2234 if (offset == 0) {
2235 rv = -EINVAL;
2236 goto out;
2237 }
2238 if (mddev->bitmap_info.external == 0 &&
2239 mddev->major_version == 0 &&
2240 offset != mddev->bitmap_info.default_offset) {
2241 rv = -EINVAL;
2242 goto out;
2243 }
2244 mddev->bitmap_info.offset = offset;
2245 if (mddev->pers) {
2246 struct bitmap *bitmap;
2247 mddev->pers->quiesce(mddev, 1);
2248 bitmap = bitmap_create(mddev, -1);
2249 if (IS_ERR(bitmap))
2250 rv = PTR_ERR(bitmap);
2251 else {
2252 mddev->bitmap = bitmap;
2253 rv = bitmap_load(mddev);
2254 if (rv)
2255 mddev->bitmap_info.offset = 0;
2256 }
2257 mddev->pers->quiesce(mddev, 0);
2258 if (rv) {
2259 bitmap_destroy(mddev);
2260 goto out;
2261 }
2262 }
2263 }
2264 }
2265 if (!mddev->external) {
2266 /* Ensure new bitmap info is stored in
2267 * metadata promptly.
2268 */
2269 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2270 md_wakeup_thread(mddev->thread);
2271 }
2272 rv = 0;
2273 out:
2274 mddev_unlock(mddev);
2275 if (rv)
2276 return rv;
2277 return len;
2278 }
2279
2280 static struct md_sysfs_entry bitmap_location =
2281 __ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
2282
2283 /* 'bitmap/space' is the space available at 'location' for the
2284 * bitmap. This allows the kernel to know when it is safe to
2285 * resize the bitmap to match a resized array.
2286 */
2287 static ssize_t
2288 space_show(struct mddev *mddev, char *page)
2289 {
2290 return sprintf(page, "%lu\n", mddev->bitmap_info.space);
2291 }
2292
2293 static ssize_t
2294 space_store(struct mddev *mddev, const char *buf, size_t len)
2295 {
2296 unsigned long sectors;
2297 int rv;
2298
2299 rv = kstrtoul(buf, 10, &sectors);
2300 if (rv)
2301 return rv;
2302
2303 if (sectors == 0)
2304 return -EINVAL;
2305
2306 if (mddev->bitmap &&
2307 sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
2308 return -EFBIG; /* Bitmap is too big for this small space */
2309
2310 /* could make sure it isn't too big, but that isn't really
2311 * needed - user-space should be careful.
2312 */
2313 mddev->bitmap_info.space = sectors;
2314 return len;
2315 }
2316
2317 static struct md_sysfs_entry bitmap_space =
2318 __ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
2319
2320 static ssize_t
2321 timeout_show(struct mddev *mddev, char *page)
2322 {
2323 ssize_t len;
2324 unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
2325 unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
2326
2327 len = sprintf(page, "%lu", secs);
2328 if (jifs)
2329 len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
2330 len += sprintf(page+len, "\n");
2331 return len;
2332 }
2333
2334 static ssize_t
2335 timeout_store(struct mddev *mddev, const char *buf, size_t len)
2336 {
2337 /* timeout can be set at any time */
2338 unsigned long timeout;
2339 int rv = strict_strtoul_scaled(buf, &timeout, 4);
2340 if (rv)
2341 return rv;
2342
2343 /* just to make sure we don't overflow... */
2344 if (timeout >= LONG_MAX / HZ)
2345 return -EINVAL;
2346
2347 timeout = timeout * HZ / 10000;
2348
2349 if (timeout >= MAX_SCHEDULE_TIMEOUT)
2350 timeout = MAX_SCHEDULE_TIMEOUT-1;
2351 if (timeout < 1)
2352 timeout = 1;
2353 mddev->bitmap_info.daemon_sleep = timeout;
2354 if (mddev->thread) {
2355 /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
2356 * the bitmap is all clean and we don't need to
2357 * adjust the timeout right now
2358 */
2359 if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
2360 mddev->thread->timeout = timeout;
2361 md_wakeup_thread(mddev->thread);
2362 }
2363 }
2364 return len;
2365 }
2366
2367 static struct md_sysfs_entry bitmap_timeout =
2368 __ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2369
2370 static ssize_t
2371 backlog_show(struct mddev *mddev, char *page)
2372 {
2373 return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2374 }
2375
2376 static ssize_t
2377 backlog_store(struct mddev *mddev, const char *buf, size_t len)
2378 {
2379 unsigned long backlog;
2380 int rv = kstrtoul(buf, 10, &backlog);
2381 if (rv)
2382 return rv;
2383 if (backlog > COUNTER_MAX)
2384 return -EINVAL;
2385 mddev->bitmap_info.max_write_behind = backlog;
2386 return len;
2387 }
2388
2389 static struct md_sysfs_entry bitmap_backlog =
2390 __ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2391
2392 static ssize_t
2393 chunksize_show(struct mddev *mddev, char *page)
2394 {
2395 return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2396 }
2397
2398 static ssize_t
2399 chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2400 {
2401 /* Can only be changed when no bitmap is active */
2402 int rv;
2403 unsigned long csize;
2404 if (mddev->bitmap)
2405 return -EBUSY;
2406 rv = kstrtoul(buf, 10, &csize);
2407 if (rv)
2408 return rv;
2409 if (csize < 512 ||
2410 !is_power_of_2(csize))
2411 return -EINVAL;
2412 mddev->bitmap_info.chunksize = csize;
2413 return len;
2414 }
2415
2416 static struct md_sysfs_entry bitmap_chunksize =
2417 __ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2418
2419 static ssize_t metadata_show(struct mddev *mddev, char *page)
2420 {
2421 if (mddev_is_clustered(mddev))
2422 return sprintf(page, "clustered\n");
2423 return sprintf(page, "%s\n", (mddev->bitmap_info.external
2424 ? "external" : "internal"));
2425 }
2426
2427 static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2428 {
2429 if (mddev->bitmap ||
2430 mddev->bitmap_info.file ||
2431 mddev->bitmap_info.offset)
2432 return -EBUSY;
2433 if (strncmp(buf, "external", 8) == 0)
2434 mddev->bitmap_info.external = 1;
2435 else if ((strncmp(buf, "internal", 8) == 0) ||
2436 (strncmp(buf, "clustered", 9) == 0))
2437 mddev->bitmap_info.external = 0;
2438 else
2439 return -EINVAL;
2440 return len;
2441 }
2442
2443 static struct md_sysfs_entry bitmap_metadata =
2444 __ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2445
2446 static ssize_t can_clear_show(struct mddev *mddev, char *page)
2447 {
2448 int len;
2449 spin_lock(&mddev->lock);
2450 if (mddev->bitmap)
2451 len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2452 "false" : "true"));
2453 else
2454 len = sprintf(page, "\n");
2455 spin_unlock(&mddev->lock);
2456 return len;
2457 }
2458
2459 static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2460 {
2461 if (mddev->bitmap == NULL)
2462 return -ENOENT;
2463 if (strncmp(buf, "false", 5) == 0)
2464 mddev->bitmap->need_sync = 1;
2465 else if (strncmp(buf, "true", 4) == 0) {
2466 if (mddev->degraded)
2467 return -EBUSY;
2468 mddev->bitmap->need_sync = 0;
2469 } else
2470 return -EINVAL;
2471 return len;
2472 }
2473
2474 static struct md_sysfs_entry bitmap_can_clear =
2475 __ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2476
2477 static ssize_t
2478 behind_writes_used_show(struct mddev *mddev, char *page)
2479 {
2480 ssize_t ret;
2481 spin_lock(&mddev->lock);
2482 if (mddev->bitmap == NULL)
2483 ret = sprintf(page, "0\n");
2484 else
2485 ret = sprintf(page, "%lu\n",
2486 mddev->bitmap->behind_writes_used);
2487 spin_unlock(&mddev->lock);
2488 return ret;
2489 }
2490
2491 static ssize_t
2492 behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2493 {
2494 if (mddev->bitmap)
2495 mddev->bitmap->behind_writes_used = 0;
2496 return len;
2497 }
2498
2499 static struct md_sysfs_entry max_backlog_used =
2500 __ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2501 behind_writes_used_show, behind_writes_used_reset);
2502
2503 static struct attribute *md_bitmap_attrs[] = {
2504 &bitmap_location.attr,
2505 &bitmap_space.attr,
2506 &bitmap_timeout.attr,
2507 &bitmap_backlog.attr,
2508 &bitmap_chunksize.attr,
2509 &bitmap_metadata.attr,
2510 &bitmap_can_clear.attr,
2511 &max_backlog_used.attr,
2512 NULL
2513 };
2514 struct attribute_group md_bitmap_group = {
2515 .name = "bitmap",
2516 .attrs = md_bitmap_attrs,
2517 };
2518
Linux with added FPC-III support