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