[PATCH] md/bitmap: cleaner separation of page attribute handlers in md/bitmap
[pandora-kernel.git] / drivers / md / bitmap.c
1 /*
2  * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
3  *
4  * bitmap_create  - sets up the bitmap structure
5  * bitmap_destroy - destroys the bitmap structure
6  *
7  * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
8  * - added disk storage for bitmap
9  * - changes to allow various bitmap chunk sizes
10  */
11
12 /*
13  * Still to do:
14  *
15  * flush after percent set rather than just time based. (maybe both).
16  * wait if count gets too high, wake when it drops to half.
17  * allow bitmap to be mirrored with superblock (before or after...)
18  * allow hot-add to re-instate a current device.
19  * allow hot-add of bitmap after quiessing device
20  */
21
22 #include <linux/module.h>
23 #include <linux/errno.h>
24 #include <linux/slab.h>
25 #include <linux/init.h>
26 #include <linux/config.h>
27 #include <linux/timer.h>
28 #include <linux/sched.h>
29 #include <linux/list.h>
30 #include <linux/file.h>
31 #include <linux/mount.h>
32 #include <linux/buffer_head.h>
33 #include <linux/raid/md.h>
34 #include <linux/raid/bitmap.h>
35
36 /* debug macros */
37
38 #define DEBUG 0
39
40 #if DEBUG
41 /* these are for debugging purposes only! */
42
43 /* define one and only one of these */
44 #define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */
45 #define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/
46 #define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */
47 #define INJECT_FAULTS_4 0 /* undef */
48 #define INJECT_FAULTS_5 0 /* undef */
49 #define INJECT_FAULTS_6 0
50
51 /* if these are defined, the driver will fail! debug only */
52 #define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */
53 #define INJECT_FATAL_FAULT_2 0 /* undef */
54 #define INJECT_FATAL_FAULT_3 0 /* undef */
55 #endif
56
57 //#define DPRINTK PRINTK /* set this NULL to avoid verbose debug output */
58 #define DPRINTK(x...) do { } while(0)
59
60 #ifndef PRINTK
61 #  if DEBUG > 0
62 #    define PRINTK(x...) printk(KERN_DEBUG x)
63 #  else
64 #    define PRINTK(x...)
65 #  endif
66 #endif
67
68 static inline char * bmname(struct bitmap *bitmap)
69 {
70         return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
71 }
72
73
74 /*
75  * test if the bitmap is active
76  */
77 int bitmap_active(struct bitmap *bitmap)
78 {
79         unsigned long flags;
80         int res = 0;
81
82         if (!bitmap)
83                 return res;
84         spin_lock_irqsave(&bitmap->lock, flags);
85         res = bitmap->flags & BITMAP_ACTIVE;
86         spin_unlock_irqrestore(&bitmap->lock, flags);
87         return res;
88 }
89
90 #define WRITE_POOL_SIZE 256
91
92 /*
93  * just a placeholder - calls kmalloc for bitmap pages
94  */
95 static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
96 {
97         unsigned char *page;
98
99 #ifdef INJECT_FAULTS_1
100         page = NULL;
101 #else
102         page = kmalloc(PAGE_SIZE, GFP_NOIO);
103 #endif
104         if (!page)
105                 printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
106         else
107                 PRINTK("%s: bitmap_alloc_page: allocated page at %p\n",
108                         bmname(bitmap), page);
109         return page;
110 }
111
112 /*
113  * for now just a placeholder -- just calls kfree for bitmap pages
114  */
115 static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page)
116 {
117         PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page);
118         kfree(page);
119 }
120
121 /*
122  * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
123  *
124  * 1) check to see if this page is allocated, if it's not then try to alloc
125  * 2) if the alloc fails, set the page's hijacked flag so we'll use the
126  *    page pointer directly as a counter
127  *
128  * if we find our page, we increment the page's refcount so that it stays
129  * allocated while we're using it
130  */
131 static int bitmap_checkpage(struct bitmap *bitmap, unsigned long page, int create)
132 {
133         unsigned char *mappage;
134
135         if (page >= bitmap->pages) {
136                 printk(KERN_ALERT
137                         "%s: invalid bitmap page request: %lu (> %lu)\n",
138                         bmname(bitmap), page, bitmap->pages-1);
139                 return -EINVAL;
140         }
141
142
143         if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
144                 return 0;
145
146         if (bitmap->bp[page].map) /* page is already allocated, just return */
147                 return 0;
148
149         if (!create)
150                 return -ENOENT;
151
152         spin_unlock_irq(&bitmap->lock);
153
154         /* this page has not been allocated yet */
155
156         if ((mappage = bitmap_alloc_page(bitmap)) == NULL) {
157                 PRINTK("%s: bitmap map page allocation failed, hijacking\n",
158                         bmname(bitmap));
159                 /* failed - set the hijacked flag so that we can use the
160                  * pointer as a counter */
161                 spin_lock_irq(&bitmap->lock);
162                 if (!bitmap->bp[page].map)
163                         bitmap->bp[page].hijacked = 1;
164                 goto out;
165         }
166
167         /* got a page */
168
169         spin_lock_irq(&bitmap->lock);
170
171         /* recheck the page */
172
173         if (bitmap->bp[page].map || bitmap->bp[page].hijacked) {
174                 /* somebody beat us to getting the page */
175                 bitmap_free_page(bitmap, mappage);
176                 return 0;
177         }
178
179         /* no page was in place and we have one, so install it */
180
181         memset(mappage, 0, PAGE_SIZE);
182         bitmap->bp[page].map = mappage;
183         bitmap->missing_pages--;
184 out:
185         return 0;
186 }
187
188
189 /* if page is completely empty, put it back on the free list, or dealloc it */
190 /* if page was hijacked, unmark the flag so it might get alloced next time */
191 /* Note: lock should be held when calling this */
192 static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
193 {
194         char *ptr;
195
196         if (bitmap->bp[page].count) /* page is still busy */
197                 return;
198
199         /* page is no longer in use, it can be released */
200
201         if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
202                 bitmap->bp[page].hijacked = 0;
203                 bitmap->bp[page].map = NULL;
204                 return;
205         }
206
207         /* normal case, free the page */
208
209 #if 0
210 /* actually ... let's not.  We will probably need the page again exactly when
211  * memory is tight and we are flusing to disk
212  */
213         return;
214 #else
215         ptr = bitmap->bp[page].map;
216         bitmap->bp[page].map = NULL;
217         bitmap->missing_pages++;
218         bitmap_free_page(bitmap, ptr);
219         return;
220 #endif
221 }
222
223
224 /*
225  * bitmap file handling - read and write the bitmap file and its superblock
226  */
227
228 /* copy the pathname of a file to a buffer */
229 char *file_path(struct file *file, char *buf, int count)
230 {
231         struct dentry *d;
232         struct vfsmount *v;
233
234         if (!buf)
235                 return NULL;
236
237         d = file->f_dentry;
238         v = file->f_vfsmnt;
239
240         buf = d_path(d, v, buf, count);
241
242         return IS_ERR(buf) ? NULL : buf;
243 }
244
245 /*
246  * basic page I/O operations
247  */
248
249 /* IO operations when bitmap is stored near all superblocks */
250 static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long index)
251 {
252         /* choose a good rdev and read the page from there */
253
254         mdk_rdev_t *rdev;
255         struct list_head *tmp;
256         struct page *page = alloc_page(GFP_KERNEL);
257         sector_t target;
258
259         if (!page)
260                 return ERR_PTR(-ENOMEM);
261
262         ITERATE_RDEV(mddev, rdev, tmp) {
263                 if (! test_bit(In_sync, &rdev->flags)
264                     || test_bit(Faulty, &rdev->flags))
265                         continue;
266
267                 target = (rdev->sb_offset << 1) + offset + index * (PAGE_SIZE/512);
268
269                 if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
270                         page->index = index;
271                         return page;
272                 }
273         }
274         return ERR_PTR(-EIO);
275
276 }
277
278 static int write_sb_page(mddev_t *mddev, long offset, struct page *page, int wait)
279 {
280         mdk_rdev_t *rdev;
281         struct list_head *tmp;
282
283         ITERATE_RDEV(mddev, rdev, tmp)
284                 if (test_bit(In_sync, &rdev->flags)
285                     && !test_bit(Faulty, &rdev->flags))
286                         md_super_write(mddev, rdev,
287                                        (rdev->sb_offset<<1) + offset
288                                        + page->index * (PAGE_SIZE/512),
289                                        PAGE_SIZE,
290                                        page);
291
292         if (wait)
293                 md_super_wait(mddev);
294         return 0;
295 }
296
297 /*
298  * write out a page to a file
299  */
300 static int write_page(struct bitmap *bitmap, struct page *page, int wait)
301 {
302         int ret = -ENOMEM;
303
304         if (bitmap->file == NULL)
305                 return write_sb_page(bitmap->mddev, bitmap->offset, page, wait);
306
307         flush_dcache_page(page); /* make sure visible to anyone reading the file */
308
309         if (wait)
310                 lock_page(page);
311         else {
312                 if (TestSetPageLocked(page))
313                         return -EAGAIN; /* already locked */
314                 if (PageWriteback(page)) {
315                         unlock_page(page);
316                         return -EAGAIN;
317                 }
318         }
319
320         ret = page->mapping->a_ops->prepare_write(bitmap->file, page, 0, PAGE_SIZE);
321         if (!ret)
322                 ret = page->mapping->a_ops->commit_write(bitmap->file, page, 0,
323                         PAGE_SIZE);
324         if (ret) {
325                 unlock_page(page);
326                 return ret;
327         }
328
329         set_page_dirty(page); /* force it to be written out */
330
331         if (!wait) {
332                 /* add to list to be waited for */
333                 struct page_list *item = mempool_alloc(bitmap->write_pool, GFP_NOIO);
334                 item->page = page;
335                 get_page(page);
336                 spin_lock(&bitmap->write_lock);
337                 list_add(&item->list, &bitmap->complete_pages);
338                 spin_unlock(&bitmap->write_lock);
339         }
340         return write_one_page(page, wait);
341 }
342
343 /* read a page from a file, pinning it into cache, and return bytes_read */
344 static struct page *read_page(struct file *file, unsigned long index,
345                                         unsigned long *bytes_read)
346 {
347         struct inode *inode = file->f_mapping->host;
348         struct page *page = NULL;
349         loff_t isize = i_size_read(inode);
350         unsigned long end_index = isize >> PAGE_SHIFT;
351
352         PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_SIZE,
353                         (unsigned long long)index << PAGE_SHIFT);
354
355         page = read_cache_page(inode->i_mapping, index,
356                         (filler_t *)inode->i_mapping->a_ops->readpage, file);
357         if (IS_ERR(page))
358                 goto out;
359         wait_on_page_locked(page);
360         if (!PageUptodate(page) || PageError(page)) {
361                 put_page(page);
362                 page = ERR_PTR(-EIO);
363                 goto out;
364         }
365
366         if (index > end_index) /* we have read beyond EOF */
367                 *bytes_read = 0;
368         else if (index == end_index) /* possible short read */
369                 *bytes_read = isize & ~PAGE_MASK;
370         else
371                 *bytes_read = PAGE_SIZE; /* got a full page */
372 out:
373         if (IS_ERR(page))
374                 printk(KERN_ALERT "md: bitmap read error: (%dB @ %Lu): %ld\n",
375                         (int)PAGE_SIZE,
376                         (unsigned long long)index << PAGE_SHIFT,
377                         PTR_ERR(page));
378         return page;
379 }
380
381 /*
382  * bitmap file superblock operations
383  */
384
385 /* update the event counter and sync the superblock to disk */
386 int bitmap_update_sb(struct bitmap *bitmap)
387 {
388         bitmap_super_t *sb;
389         unsigned long flags;
390
391         if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
392                 return 0;
393         spin_lock_irqsave(&bitmap->lock, flags);
394         if (!bitmap->sb_page) { /* no superblock */
395                 spin_unlock_irqrestore(&bitmap->lock, flags);
396                 return 0;
397         }
398         spin_unlock_irqrestore(&bitmap->lock, flags);
399         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
400         sb->events = cpu_to_le64(bitmap->mddev->events);
401         if (!bitmap->mddev->degraded)
402                 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
403         kunmap_atomic(sb, KM_USER0);
404         return write_page(bitmap, bitmap->sb_page, 1);
405 }
406
407 /* print out the bitmap file superblock */
408 void bitmap_print_sb(struct bitmap *bitmap)
409 {
410         bitmap_super_t *sb;
411
412         if (!bitmap || !bitmap->sb_page)
413                 return;
414         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
415         printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
416         printk(KERN_DEBUG "         magic: %08x\n", le32_to_cpu(sb->magic));
417         printk(KERN_DEBUG "       version: %d\n", le32_to_cpu(sb->version));
418         printk(KERN_DEBUG "          uuid: %08x.%08x.%08x.%08x\n",
419                                         *(__u32 *)(sb->uuid+0),
420                                         *(__u32 *)(sb->uuid+4),
421                                         *(__u32 *)(sb->uuid+8),
422                                         *(__u32 *)(sb->uuid+12));
423         printk(KERN_DEBUG "        events: %llu\n",
424                         (unsigned long long) le64_to_cpu(sb->events));
425         printk(KERN_DEBUG "events cleared: %llu\n",
426                         (unsigned long long) le64_to_cpu(sb->events_cleared));
427         printk(KERN_DEBUG "         state: %08x\n", le32_to_cpu(sb->state));
428         printk(KERN_DEBUG "     chunksize: %d B\n", le32_to_cpu(sb->chunksize));
429         printk(KERN_DEBUG "  daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
430         printk(KERN_DEBUG "     sync size: %llu KB\n",
431                         (unsigned long long)le64_to_cpu(sb->sync_size)/2);
432         printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
433         kunmap_atomic(sb, KM_USER0);
434 }
435
436 /* read the superblock from the bitmap file and initialize some bitmap fields */
437 static int bitmap_read_sb(struct bitmap *bitmap)
438 {
439         char *reason = NULL;
440         bitmap_super_t *sb;
441         unsigned long chunksize, daemon_sleep, write_behind;
442         unsigned long bytes_read;
443         unsigned long long events;
444         int err = -EINVAL;
445
446         /* page 0 is the superblock, read it... */
447         if (bitmap->file)
448                 bitmap->sb_page = read_page(bitmap->file, 0, &bytes_read);
449         else {
450                 bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0);
451                 bytes_read = PAGE_SIZE;
452         }
453         if (IS_ERR(bitmap->sb_page)) {
454                 err = PTR_ERR(bitmap->sb_page);
455                 bitmap->sb_page = NULL;
456                 return err;
457         }
458
459         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
460
461         if (bytes_read < sizeof(*sb)) { /* short read */
462                 printk(KERN_INFO "%s: bitmap file superblock truncated\n",
463                         bmname(bitmap));
464                 err = -ENOSPC;
465                 goto out;
466         }
467
468         chunksize = le32_to_cpu(sb->chunksize);
469         daemon_sleep = le32_to_cpu(sb->daemon_sleep);
470         write_behind = le32_to_cpu(sb->write_behind);
471
472         /* verify that the bitmap-specific fields are valid */
473         if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
474                 reason = "bad magic";
475         else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
476                  le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
477                 reason = "unrecognized superblock version";
478         else if (chunksize < PAGE_SIZE)
479                 reason = "bitmap chunksize too small";
480         else if ((1 << ffz(~chunksize)) != chunksize)
481                 reason = "bitmap chunksize not a power of 2";
482         else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT / HZ)
483                 reason = "daemon sleep period out of range";
484         else if (write_behind > COUNTER_MAX)
485                 reason = "write-behind limit out of range (0 - 16383)";
486         if (reason) {
487                 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
488                         bmname(bitmap), reason);
489                 goto out;
490         }
491
492         /* keep the array size field of the bitmap superblock up to date */
493         sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
494
495         if (!bitmap->mddev->persistent)
496                 goto success;
497
498         /*
499          * if we have a persistent array superblock, compare the
500          * bitmap's UUID and event counter to the mddev's
501          */
502         if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
503                 printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n",
504                         bmname(bitmap));
505                 goto out;
506         }
507         events = le64_to_cpu(sb->events);
508         if (events < bitmap->mddev->events) {
509                 printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) "
510                         "-- forcing full recovery\n", bmname(bitmap), events,
511                         (unsigned long long) bitmap->mddev->events);
512                 sb->state |= BITMAP_STALE;
513         }
514 success:
515         /* assign fields using values from superblock */
516         bitmap->chunksize = chunksize;
517         bitmap->daemon_sleep = daemon_sleep;
518         bitmap->daemon_lastrun = jiffies;
519         bitmap->max_write_behind = write_behind;
520         bitmap->flags |= sb->state;
521         if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
522                 bitmap->flags |= BITMAP_HOSTENDIAN;
523         bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
524         if (sb->state & BITMAP_STALE)
525                 bitmap->events_cleared = bitmap->mddev->events;
526         err = 0;
527 out:
528         kunmap_atomic(sb, KM_USER0);
529         if (err)
530                 bitmap_print_sb(bitmap);
531         return err;
532 }
533
534 enum bitmap_mask_op {
535         MASK_SET,
536         MASK_UNSET
537 };
538
539 /* record the state of the bitmap in the superblock */
540 static void bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
541                                 enum bitmap_mask_op op)
542 {
543         bitmap_super_t *sb;
544         unsigned long flags;
545
546         spin_lock_irqsave(&bitmap->lock, flags);
547         if (!bitmap->sb_page) { /* can't set the state */
548                 spin_unlock_irqrestore(&bitmap->lock, flags);
549                 return;
550         }
551         get_page(bitmap->sb_page);
552         spin_unlock_irqrestore(&bitmap->lock, flags);
553         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
554         switch (op) {
555                 case MASK_SET: sb->state |= bits;
556                                 break;
557                 case MASK_UNSET: sb->state &= ~bits;
558                                 break;
559                 default: BUG();
560         }
561         kunmap_atomic(sb, KM_USER0);
562         put_page(bitmap->sb_page);
563 }
564
565 /*
566  * general bitmap file operations
567  */
568
569 /* calculate the index of the page that contains this bit */
570 static inline unsigned long file_page_index(unsigned long chunk)
571 {
572         return CHUNK_BIT_OFFSET(chunk) >> PAGE_BIT_SHIFT;
573 }
574
575 /* calculate the (bit) offset of this bit within a page */
576 static inline unsigned long file_page_offset(unsigned long chunk)
577 {
578         return CHUNK_BIT_OFFSET(chunk) & (PAGE_BITS - 1);
579 }
580
581 /*
582  * return a pointer to the page in the filemap that contains the given bit
583  *
584  * this lookup is complicated by the fact that the bitmap sb might be exactly
585  * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
586  * 0 or page 1
587  */
588 static inline struct page *filemap_get_page(struct bitmap *bitmap,
589                                         unsigned long chunk)
590 {
591         return bitmap->filemap[file_page_index(chunk) - file_page_index(0)];
592 }
593
594
595 static void bitmap_file_unmap(struct bitmap *bitmap)
596 {
597         struct page **map, *sb_page;
598         unsigned long *attr;
599         int pages;
600         unsigned long flags;
601
602         spin_lock_irqsave(&bitmap->lock, flags);
603         map = bitmap->filemap;
604         bitmap->filemap = NULL;
605         attr = bitmap->filemap_attr;
606         bitmap->filemap_attr = NULL;
607         pages = bitmap->file_pages;
608         bitmap->file_pages = 0;
609         sb_page = bitmap->sb_page;
610         bitmap->sb_page = NULL;
611         spin_unlock_irqrestore(&bitmap->lock, flags);
612
613         while (pages--)
614                 if (map[pages]->index != 0) /* 0 is sb_page, release it below */
615                         put_page(map[pages]);
616         kfree(map);
617         kfree(attr);
618
619         safe_put_page(sb_page);
620 }
621
622 /* dequeue the next item in a page list -- don't call from irq context */
623 static struct page_list *dequeue_page(struct bitmap *bitmap)
624 {
625         struct page_list *item = NULL;
626         struct list_head *head = &bitmap->complete_pages;
627
628         spin_lock(&bitmap->write_lock);
629         if (list_empty(head))
630                 goto out;
631         item = list_entry(head->prev, struct page_list, list);
632         list_del(head->prev);
633 out:
634         spin_unlock(&bitmap->write_lock);
635         return item;
636 }
637
638 static void drain_write_queues(struct bitmap *bitmap)
639 {
640         struct page_list *item;
641
642         while ((item = dequeue_page(bitmap))) {
643                 /* don't bother to wait */
644                 put_page(item->page);
645                 mempool_free(item, bitmap->write_pool);
646         }
647 }
648
649 static void bitmap_file_put(struct bitmap *bitmap)
650 {
651         struct file *file;
652         struct inode *inode;
653         unsigned long flags;
654
655         spin_lock_irqsave(&bitmap->lock, flags);
656         file = bitmap->file;
657         bitmap->file = NULL;
658         spin_unlock_irqrestore(&bitmap->lock, flags);
659
660         drain_write_queues(bitmap);
661
662         bitmap_file_unmap(bitmap);
663
664         if (file) {
665                 inode = file->f_mapping->host;
666                 spin_lock(&inode->i_lock);
667                 atomic_set(&inode->i_writecount, 1); /* allow writes again */
668                 spin_unlock(&inode->i_lock);
669                 fput(file);
670         }
671 }
672
673
674 /*
675  * bitmap_file_kick - if an error occurs while manipulating the bitmap file
676  * then it is no longer reliable, so we stop using it and we mark the file
677  * as failed in the superblock
678  */
679 static void bitmap_file_kick(struct bitmap *bitmap)
680 {
681         char *path, *ptr = NULL;
682
683         bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET);
684         bitmap_update_sb(bitmap);
685
686         if (bitmap->file) {
687                 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
688                 if (path)
689                         ptr = file_path(bitmap->file, path, PAGE_SIZE);
690
691                 printk(KERN_ALERT "%s: kicking failed bitmap file %s from array!\n",
692                        bmname(bitmap), ptr ? ptr : "");
693
694                 kfree(path);
695         }
696
697         bitmap_file_put(bitmap);
698
699         return;
700 }
701
702 enum bitmap_page_attr {
703         BITMAP_PAGE_DIRTY = 1, // there are set bits that need to be synced
704         BITMAP_PAGE_CLEAN = 2, // there are bits that might need to be cleared
705         BITMAP_PAGE_NEEDWRITE=4, // there are cleared bits that need to be synced
706 };
707
708 static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
709                                 enum bitmap_page_attr attr)
710 {
711         bitmap->filemap_attr[page->index] |= attr;
712 }
713
714 static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
715                                 enum bitmap_page_attr attr)
716 {
717         bitmap->filemap_attr[page->index] &= ~attr;
718 }
719
720 static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
721                                            enum bitmap_page_attr attr)
722 {
723         return bitmap->filemap_attr[page->index] & attr;
724 }
725
726 /*
727  * bitmap_file_set_bit -- called before performing a write to the md device
728  * to set (and eventually sync) a particular bit in the bitmap file
729  *
730  * we set the bit immediately, then we record the page number so that
731  * when an unplug occurs, we can flush the dirty pages out to disk
732  */
733 static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
734 {
735         unsigned long bit;
736         struct page *page;
737         void *kaddr;
738         unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
739
740         if (!bitmap->filemap) {
741                 return;
742         }
743
744         page = filemap_get_page(bitmap, chunk);
745         bit = file_page_offset(chunk);
746
747
748         /* make sure the page stays cached until it gets written out */
749         if (! test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY))
750                 get_page(page);
751
752         /* set the bit */
753         kaddr = kmap_atomic(page, KM_USER0);
754         if (bitmap->flags & BITMAP_HOSTENDIAN)
755                 set_bit(bit, kaddr);
756         else
757                 ext2_set_bit(bit, kaddr);
758         kunmap_atomic(kaddr, KM_USER0);
759         PRINTK("set file bit %lu page %lu\n", bit, page->index);
760
761         /* record page number so it gets flushed to disk when unplug occurs */
762         set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
763
764 }
765
766 static void bitmap_writeback(struct bitmap *bitmap);
767
768 /* this gets called when the md device is ready to unplug its underlying
769  * (slave) device queues -- before we let any writes go down, we need to
770  * sync the dirty pages of the bitmap file to disk */
771 int bitmap_unplug(struct bitmap *bitmap)
772 {
773         unsigned long i, flags;
774         int dirty, need_write;
775         struct page *page;
776         int wait = 0;
777         int err;
778
779         if (!bitmap)
780                 return 0;
781
782         /* look at each page to see if there are any set bits that need to be
783          * flushed out to disk */
784         for (i = 0; i < bitmap->file_pages; i++) {
785                 spin_lock_irqsave(&bitmap->lock, flags);
786                 if (!bitmap->filemap) {
787                         spin_unlock_irqrestore(&bitmap->lock, flags);
788                         return 0;
789                 }
790                 page = bitmap->filemap[i];
791                 dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
792                 need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
793                 clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
794                 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
795                 if (dirty)
796                         wait = 1;
797                 spin_unlock_irqrestore(&bitmap->lock, flags);
798
799                 if (dirty | need_write) {
800                         err = write_page(bitmap, page, 0);
801                         if (err == -EAGAIN) {
802                                 if (dirty)
803                                         err = write_page(bitmap, page, 1);
804                                 else
805                                         err = 0;
806                         }
807                         if (err)
808                                 return 1;
809                 }
810         }
811         if (wait) { /* if any writes were performed, we need to wait on them */
812                 if (bitmap->file)
813                         bitmap_writeback(bitmap);
814                 else
815                         md_super_wait(bitmap->mddev);
816         }
817         return 0;
818 }
819
820 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
821 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
822  * the in-memory bitmap from the on-disk bitmap -- also, sets up the
823  * memory mapping of the bitmap file
824  * Special cases:
825  *   if there's no bitmap file, or if the bitmap file had been
826  *   previously kicked from the array, we mark all the bits as
827  *   1's in order to cause a full resync.
828  *
829  * We ignore all bits for sectors that end earlier than 'start'.
830  * This is used when reading an out-of-date bitmap...
831  */
832 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
833 {
834         unsigned long i, chunks, index, oldindex, bit;
835         struct page *page = NULL, *oldpage = NULL;
836         unsigned long num_pages, bit_cnt = 0;
837         struct file *file;
838         unsigned long bytes, offset, dummy;
839         int outofdate;
840         int ret = -ENOSPC;
841         void *paddr;
842
843         chunks = bitmap->chunks;
844         file = bitmap->file;
845
846         BUG_ON(!file && !bitmap->offset);
847
848 #ifdef INJECT_FAULTS_3
849         outofdate = 1;
850 #else
851         outofdate = bitmap->flags & BITMAP_STALE;
852 #endif
853         if (outofdate)
854                 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
855                         "recovery\n", bmname(bitmap));
856
857         bytes = (chunks + 7) / 8;
858
859         num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE;
860
861         if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
862                 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
863                         bmname(bitmap),
864                         (unsigned long) i_size_read(file->f_mapping->host),
865                         bytes + sizeof(bitmap_super_t));
866                 goto out;
867         }
868
869         ret = -ENOMEM;
870
871         bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
872         if (!bitmap->filemap)
873                 goto out;
874
875         bitmap->filemap_attr = kzalloc(sizeof(long) * num_pages, GFP_KERNEL);
876         if (!bitmap->filemap_attr)
877                 goto out;
878
879         oldindex = ~0L;
880
881         for (i = 0; i < chunks; i++) {
882                 int b;
883                 index = file_page_index(i);
884                 bit = file_page_offset(i);
885                 if (index != oldindex) { /* this is a new page, read it in */
886                         /* unmap the old page, we're done with it */
887                         if (index == 0) {
888                                 /*
889                                  * if we're here then the superblock page
890                                  * contains some bits (PAGE_SIZE != sizeof sb)
891                                  * we've already read it in, so just use it
892                                  */
893                                 page = bitmap->sb_page;
894                                 offset = sizeof(bitmap_super_t);
895                         } else if (file) {
896                                 page = read_page(file, index, &dummy);
897                                 offset = 0;
898                         } else {
899                                 page = read_sb_page(bitmap->mddev, bitmap->offset, index);
900                                 offset = 0;
901                         }
902                         if (IS_ERR(page)) { /* read error */
903                                 ret = PTR_ERR(page);
904                                 goto out;
905                         }
906
907                         oldindex = index;
908                         oldpage = page;
909
910                         if (outofdate) {
911                                 /*
912                                  * if bitmap is out of date, dirty the
913                                  * whole page and write it out
914                                  */
915                                 paddr = kmap_atomic(page, KM_USER0);
916                                 memset(paddr + offset, 0xff,
917                                        PAGE_SIZE - offset);
918                                 kunmap_atomic(paddr, KM_USER0);
919                                 ret = write_page(bitmap, page, 1);
920                                 if (ret) {
921                                         /* release, page not in filemap yet */
922                                         put_page(page);
923                                         goto out;
924                                 }
925                         }
926
927                         bitmap->filemap[bitmap->file_pages++] = page;
928                 }
929                 paddr = kmap_atomic(page, KM_USER0);
930                 if (bitmap->flags & BITMAP_HOSTENDIAN)
931                         b = test_bit(bit, paddr);
932                 else
933                         b = ext2_test_bit(bit, paddr);
934                 kunmap_atomic(paddr, KM_USER0);
935                 if (b) {
936                         /* if the disk bit is set, set the memory bit */
937                         bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap),
938                                                ((i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) >= start)
939                                 );
940                         bit_cnt++;
941                         set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
942                 }
943         }
944
945         /* everything went OK */
946         ret = 0;
947         bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
948
949         if (bit_cnt) { /* Kick recovery if any bits were set */
950                 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
951                 md_wakeup_thread(bitmap->mddev->thread);
952         }
953
954 out:
955         printk(KERN_INFO "%s: bitmap initialized from disk: "
956                 "read %lu/%lu pages, set %lu bits, status: %d\n",
957                 bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, ret);
958
959         return ret;
960 }
961
962 void bitmap_write_all(struct bitmap *bitmap)
963 {
964         /* We don't actually write all bitmap blocks here,
965          * just flag them as needing to be written
966          */
967         int i;
968
969         for (i=0; i < bitmap->file_pages; i++)
970                 set_page_attr(bitmap, bitmap->filemap[i],
971                               BITMAP_PAGE_NEEDWRITE);
972 }
973
974
975 static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
976 {
977         sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
978         unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
979         bitmap->bp[page].count += inc;
980 /*
981         if (page == 0) printk("count page 0, offset %llu: %d gives %d\n",
982                               (unsigned long long)offset, inc, bitmap->bp[page].count);
983 */
984         bitmap_checkfree(bitmap, page);
985 }
986 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
987                                             sector_t offset, int *blocks,
988                                             int create);
989
990 /*
991  * bitmap daemon -- periodically wakes up to clean bits and flush pages
992  *                      out to disk
993  */
994
995 int bitmap_daemon_work(struct bitmap *bitmap)
996 {
997         unsigned long j;
998         unsigned long flags;
999         struct page *page = NULL, *lastpage = NULL;
1000         int err = 0;
1001         int blocks;
1002         void *paddr;
1003
1004         if (bitmap == NULL)
1005                 return 0;
1006         if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ))
1007                 return 0;
1008         bitmap->daemon_lastrun = jiffies;
1009
1010         for (j = 0; j < bitmap->chunks; j++) {
1011                 bitmap_counter_t *bmc;
1012                 spin_lock_irqsave(&bitmap->lock, flags);
1013                 if (!bitmap->filemap) {
1014                         /* error or shutdown */
1015                         spin_unlock_irqrestore(&bitmap->lock, flags);
1016                         break;
1017                 }
1018
1019                 page = filemap_get_page(bitmap, j);
1020
1021                 if (page != lastpage) {
1022                         /* skip this page unless it's marked as needing cleaning */
1023                         if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
1024                                 int need_write = test_page_attr(bitmap, page,
1025                                                                 BITMAP_PAGE_NEEDWRITE);
1026                                 if (need_write) {
1027                                         get_page(page);
1028                                         clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1029                                 }
1030                                 spin_unlock_irqrestore(&bitmap->lock, flags);
1031                                 if (need_write) {
1032                                         switch (write_page(bitmap, page, 0)) {
1033                                         case -EAGAIN:
1034                                                 set_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1035                                                 break;
1036                                         case 0:
1037                                                 break;
1038                                         default:
1039                                                 bitmap_file_kick(bitmap);
1040                                         }
1041                                         put_page(page);
1042                                 }
1043                                 continue;
1044                         }
1045
1046                         /* grab the new page, sync and release the old */
1047                         get_page(page);
1048                         if (lastpage != NULL) {
1049                                 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1050                                         clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1051                                         spin_unlock_irqrestore(&bitmap->lock, flags);
1052                                         err = write_page(bitmap, lastpage, 0);
1053                                         if (err == -EAGAIN) {
1054                                                 err = 0;
1055                                                 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1056                                         }
1057                                 } else {
1058                                         set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1059                                         spin_unlock_irqrestore(&bitmap->lock, flags);
1060                                 }
1061                                 put_page(lastpage);
1062                                 if (err)
1063                                         bitmap_file_kick(bitmap);
1064                         } else
1065                                 spin_unlock_irqrestore(&bitmap->lock, flags);
1066                         lastpage = page;
1067 /*
1068                         printk("bitmap clean at page %lu\n", j);
1069 */
1070                         spin_lock_irqsave(&bitmap->lock, flags);
1071                         clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1072                 }
1073                 bmc = bitmap_get_counter(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1074                                         &blocks, 0);
1075                 if (bmc) {
1076 /*
1077   if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc);
1078 */
1079                         if (*bmc == 2) {
1080                                 *bmc=1; /* maybe clear the bit next time */
1081                                 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1082                         } else if (*bmc == 1) {
1083                                 /* we can clear the bit */
1084                                 *bmc = 0;
1085                                 bitmap_count_page(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1086                                                   -1);
1087
1088                                 /* clear the bit */
1089                                 paddr = kmap_atomic(page, KM_USER0);
1090                                 if (bitmap->flags & BITMAP_HOSTENDIAN)
1091                                         clear_bit(file_page_offset(j), paddr);
1092                                 else
1093                                         ext2_clear_bit(file_page_offset(j), paddr);
1094                                 kunmap_atomic(paddr, KM_USER0);
1095                         }
1096                 }
1097                 spin_unlock_irqrestore(&bitmap->lock, flags);
1098         }
1099
1100         /* now sync the final page */
1101         if (lastpage != NULL) {
1102                 spin_lock_irqsave(&bitmap->lock, flags);
1103                 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1104                         clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1105                         spin_unlock_irqrestore(&bitmap->lock, flags);
1106                         err = write_page(bitmap, lastpage, 0);
1107                         if (err == -EAGAIN) {
1108                                 set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1109                                 err = 0;
1110                         }
1111                 } else {
1112                         set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1113                         spin_unlock_irqrestore(&bitmap->lock, flags);
1114                 }
1115
1116                 put_page(lastpage);
1117         }
1118
1119         return err;
1120 }
1121
1122 static void bitmap_writeback(struct bitmap *bitmap)
1123 {
1124         struct page *page;
1125         struct page_list *item;
1126         int err = 0;
1127
1128         PRINTK("%s: bitmap writeback daemon woke up...\n", bmname(bitmap));
1129         /* wait on bitmap page writebacks */
1130         while ((item = dequeue_page(bitmap))) {
1131                 page = item->page;
1132                 mempool_free(item, bitmap->write_pool);
1133                 PRINTK("wait on page writeback: %p\n", page);
1134                 wait_on_page_writeback(page);
1135                 PRINTK("finished page writeback: %p\n", page);
1136
1137                 err = PageError(page);
1138                 put_page(page);
1139                 if (err) {
1140                         printk(KERN_WARNING "%s: bitmap file writeback "
1141                                "failed (page %lu): %d\n",
1142                                bmname(bitmap), page->index, err);
1143                         bitmap_file_kick(bitmap);
1144                         break;
1145                 }
1146         }
1147 }
1148
1149 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1150                                             sector_t offset, int *blocks,
1151                                             int create)
1152 {
1153         /* If 'create', we might release the lock and reclaim it.
1154          * The lock must have been taken with interrupts enabled.
1155          * If !create, we don't release the lock.
1156          */
1157         sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1158         unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1159         unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1160         sector_t csize;
1161
1162         if (bitmap_checkpage(bitmap, page, create) < 0) {
1163                 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1164                 *blocks = csize - (offset & (csize- 1));
1165                 return NULL;
1166         }
1167         /* now locked ... */
1168
1169         if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1170                 /* should we use the first or second counter field
1171                  * of the hijacked pointer? */
1172                 int hi = (pageoff > PAGE_COUNTER_MASK);
1173                 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) +
1174                                           PAGE_COUNTER_SHIFT - 1);
1175                 *blocks = csize - (offset & (csize- 1));
1176                 return  &((bitmap_counter_t *)
1177                           &bitmap->bp[page].map)[hi];
1178         } else { /* page is allocated */
1179                 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1180                 *blocks = csize - (offset & (csize- 1));
1181                 return (bitmap_counter_t *)
1182                         &(bitmap->bp[page].map[pageoff]);
1183         }
1184 }
1185
1186 int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1187 {
1188         if (!bitmap) return 0;
1189
1190         if (behind) {
1191                 atomic_inc(&bitmap->behind_writes);
1192                 PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n",
1193                   atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
1194         }
1195
1196         while (sectors) {
1197                 int blocks;
1198                 bitmap_counter_t *bmc;
1199
1200                 spin_lock_irq(&bitmap->lock);
1201                 bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
1202                 if (!bmc) {
1203                         spin_unlock_irq(&bitmap->lock);
1204                         return 0;
1205                 }
1206
1207                 switch(*bmc) {
1208                 case 0:
1209                         bitmap_file_set_bit(bitmap, offset);
1210                         bitmap_count_page(bitmap,offset, 1);
1211                         blk_plug_device(bitmap->mddev->queue);
1212                         /* fall through */
1213                 case 1:
1214                         *bmc = 2;
1215                 }
1216                 BUG_ON((*bmc & COUNTER_MAX) == COUNTER_MAX);
1217                 (*bmc)++;
1218
1219                 spin_unlock_irq(&bitmap->lock);
1220
1221                 offset += blocks;
1222                 if (sectors > blocks)
1223                         sectors -= blocks;
1224                 else sectors = 0;
1225         }
1226         return 0;
1227 }
1228
1229 void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1230                      int success, int behind)
1231 {
1232         if (!bitmap) return;
1233         if (behind) {
1234                 atomic_dec(&bitmap->behind_writes);
1235                 PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n",
1236                   atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
1237         }
1238
1239         while (sectors) {
1240                 int blocks;
1241                 unsigned long flags;
1242                 bitmap_counter_t *bmc;
1243
1244                 spin_lock_irqsave(&bitmap->lock, flags);
1245                 bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
1246                 if (!bmc) {
1247                         spin_unlock_irqrestore(&bitmap->lock, flags);
1248                         return;
1249                 }
1250
1251                 if (!success && ! (*bmc & NEEDED_MASK))
1252                         *bmc |= NEEDED_MASK;
1253
1254                 (*bmc)--;
1255                 if (*bmc <= 2) {
1256                         set_page_attr(bitmap,
1257                                       filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1258                                       BITMAP_PAGE_CLEAN);
1259                 }
1260                 spin_unlock_irqrestore(&bitmap->lock, flags);
1261                 offset += blocks;
1262                 if (sectors > blocks)
1263                         sectors -= blocks;
1264                 else sectors = 0;
1265         }
1266 }
1267
1268 int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks,
1269                         int degraded)
1270 {
1271         bitmap_counter_t *bmc;
1272         int rv;
1273         if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1274                 *blocks = 1024;
1275                 return 1; /* always resync if no bitmap */
1276         }
1277         spin_lock_irq(&bitmap->lock);
1278         bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1279         rv = 0;
1280         if (bmc) {
1281                 /* locked */
1282                 if (RESYNC(*bmc))
1283                         rv = 1;
1284                 else if (NEEDED(*bmc)) {
1285                         rv = 1;
1286                         if (!degraded) { /* don't set/clear bits if degraded */
1287                                 *bmc |= RESYNC_MASK;
1288                                 *bmc &= ~NEEDED_MASK;
1289                         }
1290                 }
1291         }
1292         spin_unlock_irq(&bitmap->lock);
1293         return rv;
1294 }
1295
1296 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted)
1297 {
1298         bitmap_counter_t *bmc;
1299         unsigned long flags;
1300 /*
1301         if (offset == 0) printk("bitmap_end_sync 0 (%d)\n", aborted);
1302 */      if (bitmap == NULL) {
1303                 *blocks = 1024;
1304                 return;
1305         }
1306         spin_lock_irqsave(&bitmap->lock, flags);
1307         bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1308         if (bmc == NULL)
1309                 goto unlock;
1310         /* locked */
1311 /*
1312         if (offset == 0) printk("bitmap_end sync found 0x%x, blocks %d\n", *bmc, *blocks);
1313 */
1314         if (RESYNC(*bmc)) {
1315                 *bmc &= ~RESYNC_MASK;
1316
1317                 if (!NEEDED(*bmc) && aborted)
1318                         *bmc |= NEEDED_MASK;
1319                 else {
1320                         if (*bmc <= 2) {
1321                                 set_page_attr(bitmap,
1322                                               filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1323                                               BITMAP_PAGE_CLEAN);
1324                         }
1325                 }
1326         }
1327  unlock:
1328         spin_unlock_irqrestore(&bitmap->lock, flags);
1329 }
1330
1331 void bitmap_close_sync(struct bitmap *bitmap)
1332 {
1333         /* Sync has finished, and any bitmap chunks that weren't synced
1334          * properly have been aborted.  It remains to us to clear the
1335          * RESYNC bit wherever it is still on
1336          */
1337         sector_t sector = 0;
1338         int blocks;
1339         if (!bitmap) return;
1340         while (sector < bitmap->mddev->resync_max_sectors) {
1341                 bitmap_end_sync(bitmap, sector, &blocks, 0);
1342 /*
1343                 if (sector < 500) printk("bitmap_close_sync: sec %llu blks %d\n",
1344                                          (unsigned long long)sector, blocks);
1345 */              sector += blocks;
1346         }
1347 }
1348
1349 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1350 {
1351         /* For each chunk covered by any of these sectors, set the
1352          * counter to 1 and set resync_needed.  They should all
1353          * be 0 at this point
1354          */
1355
1356         int secs;
1357         bitmap_counter_t *bmc;
1358         spin_lock_irq(&bitmap->lock);
1359         bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
1360         if (!bmc) {
1361                 spin_unlock_irq(&bitmap->lock);
1362                 return;
1363         }
1364         if (! *bmc) {
1365                 struct page *page;
1366                 *bmc = 1 | (needed?NEEDED_MASK:0);
1367                 bitmap_count_page(bitmap, offset, 1);
1368                 page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
1369                 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1370         }
1371         spin_unlock_irq(&bitmap->lock);
1372
1373 }
1374
1375 /*
1376  * flush out any pending updates
1377  */
1378 void bitmap_flush(mddev_t *mddev)
1379 {
1380         struct bitmap *bitmap = mddev->bitmap;
1381         int sleep;
1382
1383         if (!bitmap) /* there was no bitmap */
1384                 return;
1385
1386         /* run the daemon_work three time to ensure everything is flushed
1387          * that can be
1388          */
1389         sleep = bitmap->daemon_sleep;
1390         bitmap->daemon_sleep = 0;
1391         bitmap_daemon_work(bitmap);
1392         bitmap_daemon_work(bitmap);
1393         bitmap_daemon_work(bitmap);
1394         bitmap->daemon_sleep = sleep;
1395         bitmap_update_sb(bitmap);
1396 }
1397
1398 /*
1399  * free memory that was allocated
1400  */
1401 static void bitmap_free(struct bitmap *bitmap)
1402 {
1403         unsigned long k, pages;
1404         struct bitmap_page *bp;
1405
1406         if (!bitmap) /* there was no bitmap */
1407                 return;
1408
1409         /* release the bitmap file and kill the daemon */
1410         bitmap_file_put(bitmap);
1411
1412         bp = bitmap->bp;
1413         pages = bitmap->pages;
1414
1415         /* free all allocated memory */
1416
1417         mempool_destroy(bitmap->write_pool);
1418
1419         if (bp) /* deallocate the page memory */
1420                 for (k = 0; k < pages; k++)
1421                         if (bp[k].map && !bp[k].hijacked)
1422                                 kfree(bp[k].map);
1423         kfree(bp);
1424         kfree(bitmap);
1425 }
1426 void bitmap_destroy(mddev_t *mddev)
1427 {
1428         struct bitmap *bitmap = mddev->bitmap;
1429
1430         if (!bitmap) /* there was no bitmap */
1431                 return;
1432
1433         mddev->bitmap = NULL; /* disconnect from the md device */
1434         if (mddev->thread)
1435                 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1436
1437         bitmap_free(bitmap);
1438 }
1439
1440 /*
1441  * initialize the bitmap structure
1442  * if this returns an error, bitmap_destroy must be called to do clean up
1443  */
1444 int bitmap_create(mddev_t *mddev)
1445 {
1446         struct bitmap *bitmap;
1447         unsigned long blocks = mddev->resync_max_sectors;
1448         unsigned long chunks;
1449         unsigned long pages;
1450         struct file *file = mddev->bitmap_file;
1451         int err;
1452         sector_t start;
1453
1454         BUG_ON(sizeof(bitmap_super_t) != 256);
1455
1456         if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */
1457                 return 0;
1458
1459         BUG_ON(file && mddev->bitmap_offset);
1460
1461         bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1462         if (!bitmap)
1463                 return -ENOMEM;
1464
1465         spin_lock_init(&bitmap->lock);
1466         bitmap->mddev = mddev;
1467
1468         spin_lock_init(&bitmap->write_lock);
1469         INIT_LIST_HEAD(&bitmap->complete_pages);
1470         bitmap->write_pool = mempool_create_kmalloc_pool(WRITE_POOL_SIZE,
1471                                                 sizeof(struct page_list));
1472         err = -ENOMEM;
1473         if (!bitmap->write_pool)
1474                 goto error;
1475
1476         bitmap->file = file;
1477         bitmap->offset = mddev->bitmap_offset;
1478         if (file) get_file(file);
1479         /* read superblock from bitmap file (this sets bitmap->chunksize) */
1480         err = bitmap_read_sb(bitmap);
1481         if (err)
1482                 goto error;
1483
1484         bitmap->chunkshift = find_first_bit(&bitmap->chunksize,
1485                                         sizeof(bitmap->chunksize));
1486
1487         /* now that chunksize and chunkshift are set, we can use these macros */
1488         chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) /
1489                         CHUNK_BLOCK_RATIO(bitmap);
1490         pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1491
1492         BUG_ON(!pages);
1493
1494         bitmap->chunks = chunks;
1495         bitmap->pages = pages;
1496         bitmap->missing_pages = pages;
1497         bitmap->counter_bits = COUNTER_BITS;
1498
1499         bitmap->syncchunk = ~0UL;
1500
1501 #ifdef INJECT_FATAL_FAULT_1
1502         bitmap->bp = NULL;
1503 #else
1504         bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1505 #endif
1506         err = -ENOMEM;
1507         if (!bitmap->bp)
1508                 goto error;
1509
1510         bitmap->flags |= BITMAP_ACTIVE;
1511
1512         /* now that we have some pages available, initialize the in-memory
1513          * bitmap from the on-disk bitmap */
1514         start = 0;
1515         if (mddev->degraded == 0
1516             || bitmap->events_cleared == mddev->events)
1517                 /* no need to keep dirty bits to optimise a re-add of a missing device */
1518                 start = mddev->recovery_cp;
1519         err = bitmap_init_from_disk(bitmap, start);
1520
1521         if (err)
1522                 goto error;
1523
1524         printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1525                 pages, bmname(bitmap));
1526
1527         mddev->bitmap = bitmap;
1528
1529         mddev->thread->timeout = bitmap->daemon_sleep * HZ;
1530
1531         return bitmap_update_sb(bitmap);
1532
1533  error:
1534         bitmap_free(bitmap);
1535         return err;
1536 }
1537
1538 /* the bitmap API -- for raid personalities */
1539 EXPORT_SYMBOL(bitmap_startwrite);
1540 EXPORT_SYMBOL(bitmap_endwrite);
1541 EXPORT_SYMBOL(bitmap_start_sync);
1542 EXPORT_SYMBOL(bitmap_end_sync);
1543 EXPORT_SYMBOL(bitmap_unplug);
1544 EXPORT_SYMBOL(bitmap_close_sync);
1545 EXPORT_SYMBOL(bitmap_daemon_work);