SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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  */
  18
  19 #include <linux/module.h>
  20 #include <linux/errno.h>
  21 #include <linux/slab.h>
  22 #include <linux/init.h>
  23 #include <linux/config.h>
  24 #include <linux/timer.h>
  25 #include <linux/sched.h>
  26 #include <linux/list.h>
  27 #include <linux/file.h>
  28 #include <linux/mount.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/raid/md.h>
  31 #include <linux/raid/bitmap.h>
  32
  33 /* debug macros */
  34
  35 #define DEBUG 0
  36
  37 #if DEBUG
  38 /* these are for debugging purposes only! */
  39
  40 /* define one and only one of these */
  41 #define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */
  42 #define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/
  43 #define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */
  44 #define INJECT_FAULTS_4 0 /* undef */
  45 #define INJECT_FAULTS_5 0 /* undef */
  46 #define INJECT_FAULTS_6 0
  47
  48 /* if these are defined, the driver will fail! debug only */
  49 #define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */
  50 #define INJECT_FATAL_FAULT_2 0 /* undef */
  51 #define INJECT_FATAL_FAULT_3 0 /* undef */
  52 #endif
  53
  54 //#define DPRINTK PRINTK /* set this NULL to avoid verbose debug output */
  55 #define DPRINTK(x...) do { } while(0)
  56
  57 #ifndef PRINTK
  58 #  if DEBUG > 0
  59 #    define PRINTK(x...) printk(KERN_DEBUG x)
  60 #  else
  61 #    define PRINTK(x...)
  62 #  endif
  63 #endif
  64
  65 static inline char * bmname(struct bitmap *bitmap)
  66 {
  67         return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
  68 }
  69
  70
  71 /*
  72  * just a placeholder - calls kmalloc for bitmap pages
  73  */
  74 static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
  75 {
  76         unsigned char *page;
  77
  78 #ifdef INJECT_FAULTS_1
  79         page = NULL;
  80 #else
  81         page = kmalloc(PAGE_SIZE, GFP_NOIO);
  82 #endif
  83         if (!page)
  84                 printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
  85         else
  86                 PRINTK("%s: bitmap_alloc_page: allocated page at %p\n",
  87                         bmname(bitmap), page);
  88         return page;
  89 }
  90
  91 /*
  92  * for now just a placeholder -- just calls kfree for bitmap pages
  93  */
  94 static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page)
  95 {
  96         PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page);
  97         kfree(page);
  98 }
  99
 100 /*
 101  * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
 102  *
 103  * 1) check to see if this page is allocated, if it's not then try to alloc
 104  * 2) if the alloc fails, set the page's hijacked flag so we'll use the
 105  *    page pointer directly as a counter
 106  *
 107  * if we find our page, we increment the page's refcount so that it stays
 108  * allocated while we're using it
 109  */
 110 static int bitmap_checkpage(struct bitmap *bitmap, unsigned long page, int create)
 111 {
 112         unsigned char *mappage;
 113
 114         if (page >= bitmap->pages) {
 115                 printk(KERN_ALERT
 116                         "%s: invalid bitmap page request: %lu (> %lu)\n",
 117                         bmname(bitmap), page, bitmap->pages-1);
 118                 return -EINVAL;
 119         }
 120
 121
 122         if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
 123                 return 0;
 124
 125         if (bitmap->bp[page].map) /* page is already allocated, just return */
 126                 return 0;
 127
 128         if (!create)
 129                 return -ENOENT;
 130
 131         spin_unlock_irq(&bitmap->lock);
 132
 133         /* this page has not been allocated yet */
 134
 135         if ((mappage = bitmap_alloc_page(bitmap)) == NULL) {
 136                 PRINTK("%s: bitmap map page allocation failed, hijacking\n",
 137                         bmname(bitmap));
 138                 /* failed - set the hijacked flag so that we can use the
 139                  * pointer as a counter */
 140                 spin_lock_irq(&bitmap->lock);
 141                 if (!bitmap->bp[page].map)
 142                         bitmap->bp[page].hijacked = 1;
 143                 goto out;
 144         }
 145
 146         /* got a page */
 147
 148         spin_lock_irq(&bitmap->lock);
 149
 150         /* recheck the page */
 151
 152         if (bitmap->bp[page].map || bitmap->bp[page].hijacked) {
 153                 /* somebody beat us to getting the page */
 154                 bitmap_free_page(bitmap, mappage);
 155                 return 0;
 156         }
 157
 158         /* no page was in place and we have one, so install it */
 159
 160         memset(mappage, 0, PAGE_SIZE);
 161         bitmap->bp[page].map = mappage;
 162         bitmap->missing_pages--;
 163 out:
 164         return 0;
 165 }
 166
 167
 168 /* if page is completely empty, put it back on the free list, or dealloc it */
 169 /* if page was hijacked, unmark the flag so it might get alloced next time */
 170 /* Note: lock should be held when calling this */
 171 static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
 172 {
 173         char *ptr;
 174
 175         if (bitmap->bp[page].count) /* page is still busy */
 176                 return;
 177
 178         /* page is no longer in use, it can be released */
 179
 180         if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
 181                 bitmap->bp[page].hijacked = 0;
 182                 bitmap->bp[page].map = NULL;
 183                 return;
 184         }
 185
 186         /* normal case, free the page */
 187
 188 #if 0
 189 /* actually ... let's not.  We will probably need the page again exactly when
 190  * memory is tight and we are flusing to disk
 191  */
 192         return;
 193 #else
 194         ptr = bitmap->bp[page].map;
 195         bitmap->bp[page].map = NULL;
 196         bitmap->missing_pages++;
 197         bitmap_free_page(bitmap, ptr);
 198         return;
 199 #endif
 200 }
 201
 202
 203 /*
 204  * bitmap file handling - read and write the bitmap file and its superblock
 205  */
 206
 207 /* copy the pathname of a file to a buffer */
 208 char *file_path(struct file *file, char *buf, int count)
 209 {
 210         struct dentry *d;
 211         struct vfsmount *v;
 212
 213         if (!buf)
 214                 return NULL;
 215
 216         d = file->f_dentry;
 217         v = file->f_vfsmnt;
 218
 219         buf = d_path(d, v, buf, count);
 220
 221         return IS_ERR(buf) ? NULL : buf;
 222 }
 223
 224 /*
 225  * basic page I/O operations
 226  */
 227
 228 /* IO operations when bitmap is stored near all superblocks */
 229 static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long index)
 230 {
 231         /* choose a good rdev and read the page from there */
 232
 233         mdk_rdev_t *rdev;
 234         struct list_head *tmp;
 235         struct page *page = alloc_page(GFP_KERNEL);
 236         sector_t target;
 237
 238         if (!page)
 239                 return ERR_PTR(-ENOMEM);
 240
 241         ITERATE_RDEV(mddev, rdev, tmp) {
 242                 if (! test_bit(In_sync, &rdev->flags)
 243                     || test_bit(Faulty, &rdev->flags))
 244                         continue;
 245
 246                 target = (rdev->sb_offset << 1) + offset + index * (PAGE_SIZE/512);
 247
 248                 if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
 249                         page->index = index;
 250                         return page;
 251                 }
 252         }
 253         return ERR_PTR(-EIO);
 254
 255 }
 256
 257 static int write_sb_page(mddev_t *mddev, long offset, struct page *page, int wait)
 258 {
 259         mdk_rdev_t *rdev;
 260         struct list_head *tmp;
 261
 262         ITERATE_RDEV(mddev, rdev, tmp)
 263                 if (test_bit(In_sync, &rdev->flags)
 264                     && !test_bit(Faulty, &rdev->flags))
 265                         md_super_write(mddev, rdev,
 266                                        (rdev->sb_offset<<1) + offset
 267                                        + page->index * (PAGE_SIZE/512),
 268                                        PAGE_SIZE,
 269                                        page);
 270
 271         if (wait)
 272                 md_super_wait(mddev);
 273         return 0;
 274 }
 275
 276 /*
 277  * write out a page to a file
 278  */
 279 static int write_page(struct bitmap *bitmap, struct page *page, int wait)
 280 {
 281         struct buffer_head *bh;
 282
 283         if (bitmap->file == NULL)
 284                 return write_sb_page(bitmap->mddev, bitmap->offset, page, wait);
 285
 286         bh = page_buffers(page);
 287
 288         while (bh && bh->b_blocknr) {
 289                 atomic_inc(&bitmap->pending_writes);
 290                 set_buffer_locked(bh);
 291                 set_buffer_mapped(bh);
 292                 submit_bh(WRITE, bh);
 293                 bh = bh->b_this_page;
 294         }
 295
 296         if (wait) {
 297                 wait_event(bitmap->write_wait,
 298                            atomic_read(&bitmap->pending_writes)==0);
 299                 return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
 300         }
 301         return 0;
 302 }
 303
 304 static void end_bitmap_write(struct buffer_head *bh, int uptodate)
 305 {
 306         struct bitmap *bitmap = bh->b_private;
 307         unsigned long flags;
 308
 309         if (!uptodate) {
 310                 spin_lock_irqsave(&bitmap->lock, flags);
 311                 bitmap->flags |= BITMAP_WRITE_ERROR;
 312                 spin_unlock_irqrestore(&bitmap->lock, flags);
 313         }
 314         if (atomic_dec_and_test(&bitmap->pending_writes))
 315                 wake_up(&bitmap->write_wait);
 316 }
 317
 318 /* copied from buffer.c */
 319 static void
 320 __clear_page_buffers(struct page *page)
 321 {
 322         ClearPagePrivate(page);
 323         set_page_private(page, 0);
 324         page_cache_release(page);
 325 }
 326 static void free_buffers(struct page *page)
 327 {
 328         struct buffer_head *bh = page_buffers(page);
 329
 330         while (bh) {
 331                 struct buffer_head *next = bh->b_this_page;
 332                 free_buffer_head(bh);
 333                 bh = next;
 334         }
 335         __clear_page_buffers(page);
 336         put_page(page);
 337 }
 338
 339 /* read a page from a file.
 340  * We both read the page, and attach buffers to the page to record the
 341  * address of each block (using bmap).  These addresses will be used
 342  * to write the block later, completely bypassing the filesystem.
 343  * This usage is similar to how swap files are handled, and allows us
 344  * to write to a file with no concerns of memory allocation failing.
 345  */
 346 static struct page *read_page(struct file *file, unsigned long index,
 347                               struct bitmap *bitmap,
 348                               unsigned long count)
 349 {
 350         struct page *page = NULL;
 351         struct inode *inode = file->f_dentry->d_inode;
 352         loff_t pos = index << PAGE_SHIFT;
 353         int ret;
 354         struct buffer_head *bh;
 355         sector_t block;
 356         mm_segment_t oldfs;
 357
 358         PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_SIZE,
 359                         (unsigned long long)index << PAGE_SHIFT);
 360
 361         page = alloc_page(GFP_KERNEL);
 362         if (!page)
 363                 page = ERR_PTR(-ENOMEM);
 364         if (IS_ERR(page))
 365                 goto out;
 366
 367         oldfs = get_fs();
 368         set_fs(KERNEL_DS);
 369         ret = vfs_read(file, (char __user*) page_address(page), count, &pos);
 370         set_fs(oldfs);
 371
 372         if (ret >= 0 && ret != count)
 373                 ret = -EIO;
 374         if (ret < 0) {
 375                 put_page(page);
 376                 page = ERR_PTR(ret);
 377                 goto out;
 378         }
 379         bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
 380         if (!bh) {
 381                 put_page(page);
 382                 page = ERR_PTR(-ENOMEM);
 383                 goto out;
 384         }
 385         attach_page_buffers(page, bh);
 386         block = index << (PAGE_SHIFT - inode->i_blkbits);
 387         while (bh) {
 388                 if (count == 0)
 389                         bh->b_blocknr = 0;
 390                 else {
 391                         bh->b_blocknr = bmap(inode, block);
 392                         if (bh->b_blocknr == 0) {
 393                                 /* Cannot use this file! */
 394                                 free_buffers(page);
 395                                 page = ERR_PTR(-EINVAL);
 396                                 goto out;
 397                         }
 398                         bh->b_bdev = inode->i_sb->s_bdev;
 399                         if (count < (1<<inode->i_blkbits))
 400                                 count = 0;
 401                         else
 402                                 count -= (1<<inode->i_blkbits);
 403
 404                         bh->b_end_io = end_bitmap_write;
 405                         bh->b_private = bitmap;
 406                 }
 407                 block++;
 408                 bh = bh->b_this_page;
 409         }
 410
 411         page->index = index;
 412 out:
 413         if (IS_ERR(page))
 414                 printk(KERN_ALERT "md: bitmap read error: (%dB @ %Lu): %ld\n",
 415                         (int)PAGE_SIZE,
 416                         (unsigned long long)index << PAGE_SHIFT,
 417                         PTR_ERR(page));
 418         return page;
 419 }
 420
 421 /*
 422  * bitmap file superblock operations
 423  */
 424
 425 /* update the event counter and sync the superblock to disk */
 426 int bitmap_update_sb(struct bitmap *bitmap)
 427 {
 428         bitmap_super_t *sb;
 429         unsigned long flags;
 430
 431         if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
 432                 return 0;
 433         spin_lock_irqsave(&bitmap->lock, flags);
 434         if (!bitmap->sb_page) { /* no superblock */
 435                 spin_unlock_irqrestore(&bitmap->lock, flags);
 436                 return 0;
 437         }
 438         spin_unlock_irqrestore(&bitmap->lock, flags);
 439         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
 440         sb->events = cpu_to_le64(bitmap->mddev->events);
 441         if (!bitmap->mddev->degraded)
 442                 sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
 443         kunmap_atomic(sb, KM_USER0);
 444         return write_page(bitmap, bitmap->sb_page, 1);
 445 }
 446
 447 /* print out the bitmap file superblock */
 448 void bitmap_print_sb(struct bitmap *bitmap)
 449 {
 450         bitmap_super_t *sb;
 451
 452         if (!bitmap || !bitmap->sb_page)
 453                 return;
 454         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
 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, KM_USER0);
 474 }
 475
 476 /* read the superblock from the bitmap file and initialize some bitmap fields */
 477 static int bitmap_read_sb(struct bitmap *bitmap)
 478 {
 479         char *reason = NULL;
 480         bitmap_super_t *sb;
 481         unsigned long chunksize, daemon_sleep, write_behind;
 482         unsigned long long events;
 483         int err = -EINVAL;
 484
 485         /* page 0 is the superblock, read it... */
 486         if (bitmap->file)
 487                 bitmap->sb_page = read_page(bitmap->file, 0, bitmap, PAGE_SIZE);
 488         else {
 489                 bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0);
 490         }
 491         if (IS_ERR(bitmap->sb_page)) {
 492                 err = PTR_ERR(bitmap->sb_page);
 493                 bitmap->sb_page = NULL;
 494                 return err;
 495         }
 496
 497         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
 498
 499         chunksize = le32_to_cpu(sb->chunksize);
 500         daemon_sleep = le32_to_cpu(sb->daemon_sleep);
 501         write_behind = le32_to_cpu(sb->write_behind);
 502
 503         /* verify that the bitmap-specific fields are valid */
 504         if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
 505                 reason = "bad magic";
 506         else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
 507                  le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
 508                 reason = "unrecognized superblock version";
 509         else if (chunksize < PAGE_SIZE)
 510                 reason = "bitmap chunksize too small";
 511         else if ((1 << ffz(~chunksize)) != chunksize)
 512                 reason = "bitmap chunksize not a power of 2";
 513         else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT / HZ)
 514                 reason = "daemon sleep period out of range";
 515         else if (write_behind > COUNTER_MAX)
 516                 reason = "write-behind limit out of range (0 - 16383)";
 517         if (reason) {
 518                 printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
 519                         bmname(bitmap), reason);
 520                 goto out;
 521         }
 522
 523         /* keep the array size field of the bitmap superblock up to date */
 524         sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
 525
 526         if (!bitmap->mddev->persistent)
 527                 goto success;
 528
 529         /*
 530          * if we have a persistent array superblock, compare the
 531          * bitmap's UUID and event counter to the mddev's
 532          */
 533         if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
 534                 printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n",
 535                         bmname(bitmap));
 536                 goto out;
 537         }
 538         events = le64_to_cpu(sb->events);
 539         if (events < bitmap->mddev->events) {
 540                 printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) "
 541                         "-- forcing full recovery\n", bmname(bitmap), events,
 542                         (unsigned long long) bitmap->mddev->events);
 543                 sb->state |= BITMAP_STALE;
 544         }
 545 success:
 546         /* assign fields using values from superblock */
 547         bitmap->chunksize = chunksize;
 548         bitmap->daemon_sleep = daemon_sleep;
 549         bitmap->daemon_lastrun = jiffies;
 550         bitmap->max_write_behind = write_behind;
 551         bitmap->flags |= sb->state;
 552         if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
 553                 bitmap->flags |= BITMAP_HOSTENDIAN;
 554         bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
 555         if (sb->state & BITMAP_STALE)
 556                 bitmap->events_cleared = bitmap->mddev->events;
 557         err = 0;
 558 out:
 559         kunmap_atomic(sb, KM_USER0);
 560         if (err)
 561                 bitmap_print_sb(bitmap);
 562         return err;
 563 }
 564
 565 enum bitmap_mask_op {
 566         MASK_SET,
 567         MASK_UNSET
 568 };
 569
 570 /* record the state of the bitmap in the superblock */
 571 static void bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
 572                                 enum bitmap_mask_op op)
 573 {
 574         bitmap_super_t *sb;
 575         unsigned long flags;
 576
 577         spin_lock_irqsave(&bitmap->lock, flags);
 578         if (!bitmap->sb_page) { /* can't set the state */
 579                 spin_unlock_irqrestore(&bitmap->lock, flags);
 580                 return;
 581         }
 582         spin_unlock_irqrestore(&bitmap->lock, flags);
 583         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
 584         switch (op) {
 585                 case MASK_SET: sb->state |= bits;
 586                                 break;
 587                 case MASK_UNSET: sb->state &= ~bits;
 588                                 break;
 589                 default: BUG();
 590         }
 591         kunmap_atomic(sb, KM_USER0);
 592 }
 593
 594 /*
 595  * general bitmap file operations
 596  */
 597
 598 /* calculate the index of the page that contains this bit */
 599 static inline unsigned long file_page_index(unsigned long chunk)
 600 {
 601         return CHUNK_BIT_OFFSET(chunk) >> PAGE_BIT_SHIFT;
 602 }
 603
 604 /* calculate the (bit) offset of this bit within a page */
 605 static inline unsigned long file_page_offset(unsigned long chunk)
 606 {
 607         return CHUNK_BIT_OFFSET(chunk) & (PAGE_BITS - 1);
 608 }
 609
 610 /*
 611  * return a pointer to the page in the filemap that contains the given bit
 612  *
 613  * this lookup is complicated by the fact that the bitmap sb might be exactly
 614  * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
 615  * 0 or page 1
 616  */
 617 static inline struct page *filemap_get_page(struct bitmap *bitmap,
 618                                         unsigned long chunk)
 619 {
 620         return bitmap->filemap[file_page_index(chunk) - file_page_index(0)];
 621 }
 622
 623
 624 static void bitmap_file_unmap(struct bitmap *bitmap)
 625 {
 626         struct page **map, *sb_page;
 627         unsigned long *attr;
 628         int pages;
 629         unsigned long flags;
 630
 631         spin_lock_irqsave(&bitmap->lock, flags);
 632         map = bitmap->filemap;
 633         bitmap->filemap = NULL;
 634         attr = bitmap->filemap_attr;
 635         bitmap->filemap_attr = NULL;
 636         pages = bitmap->file_pages;
 637         bitmap->file_pages = 0;
 638         sb_page = bitmap->sb_page;
 639         bitmap->sb_page = NULL;
 640         spin_unlock_irqrestore(&bitmap->lock, flags);
 641
 642         while (pages--)
 643                 if (map[pages]->index != 0) /* 0 is sb_page, release it below */
 644                         free_buffers(map[pages]);
 645         kfree(map);
 646         kfree(attr);
 647
 648         if (sb_page)
 649                 free_buffers(sb_page);
 650 }
 651
 652 static void bitmap_file_put(struct bitmap *bitmap)
 653 {
 654         struct file *file;
 655         unsigned long flags;
 656
 657         spin_lock_irqsave(&bitmap->lock, flags);
 658         file = bitmap->file;
 659         bitmap->file = NULL;
 660         spin_unlock_irqrestore(&bitmap->lock, flags);
 661
 662         if (file)
 663                 wait_event(bitmap->write_wait,
 664                            atomic_read(&bitmap->pending_writes)==0);
 665         bitmap_file_unmap(bitmap);
 666
 667         if (file) {
 668                 struct inode *inode = file->f_dentry->d_inode;
 669                 invalidate_inode_pages(inode->i_mapping);
 670                 fput(file);
 671         }
 672 }
 673
 674
 675 /*
 676  * bitmap_file_kick - if an error occurs while manipulating the bitmap file
 677  * then it is no longer reliable, so we stop using it and we mark the file
 678  * as failed in the superblock
 679  */
 680 static void bitmap_file_kick(struct bitmap *bitmap)
 681 {
 682         char *path, *ptr = NULL;
 683
 684         bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET);
 685         bitmap_update_sb(bitmap);
 686
 687         if (bitmap->file) {
 688                 path = kmalloc(PAGE_SIZE, GFP_KERNEL);
 689                 if (path)
 690                         ptr = file_path(bitmap->file, path, PAGE_SIZE);
 691
 692                 printk(KERN_ALERT "%s: kicking failed bitmap file %s from array!\n",
 693                        bmname(bitmap), ptr ? ptr : "");
 694
 695                 kfree(path);
 696         }
 697
 698         bitmap_file_put(bitmap);
 699
 700         return;
 701 }
 702
 703 enum bitmap_page_attr {
 704         BITMAP_PAGE_DIRTY = 0, // there are set bits that need to be synced
 705         BITMAP_PAGE_CLEAN = 1, // there are bits that might need to be cleared
 706         BITMAP_PAGE_NEEDWRITE=2, // there are cleared bits that need to be synced
 707 };
 708
 709 static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
 710                                 enum bitmap_page_attr attr)
 711 {
 712         __set_bit((page->index<<2) + attr, bitmap->filemap_attr);
 713 }
 714
 715 static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
 716                                 enum bitmap_page_attr attr)
 717 {
 718         __clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
 719 }
 720
 721 static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
 722                                            enum bitmap_page_attr attr)
 723 {
 724         return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
 725 }
 726
 727 /*
 728  * bitmap_file_set_bit -- called before performing a write to the md device
 729  * to set (and eventually sync) a particular bit in the bitmap file
 730  *
 731  * we set the bit immediately, then we record the page number so that
 732  * when an unplug occurs, we can flush the dirty pages out to disk
 733  */
 734 static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
 735 {
 736         unsigned long bit;
 737         struct page *page;
 738         void *kaddr;
 739         unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
 740
 741         if (!bitmap->filemap) {
 742                 return;
 743         }
 744
 745         page = filemap_get_page(bitmap, chunk);
 746         bit = file_page_offset(chunk);
 747
 748         /* set the bit */
 749         kaddr = kmap_atomic(page, KM_USER0);
 750         if (bitmap->flags & BITMAP_HOSTENDIAN)
 751                 set_bit(bit, kaddr);
 752         else
 753                 ext2_set_bit(bit, kaddr);
 754         kunmap_atomic(kaddr, KM_USER0);
 755         PRINTK("set file bit %lu page %lu\n", bit, page->index);
 756
 757         /* record page number so it gets flushed to disk when unplug occurs */
 758         set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
 759
 760 }
 761
 762 /* this gets called when the md device is ready to unplug its underlying
 763  * (slave) device queues -- before we let any writes go down, we need to
 764  * sync the dirty pages of the bitmap file to disk */
 765 int bitmap_unplug(struct bitmap *bitmap)
 766 {
 767         unsigned long i, flags;
 768         int dirty, need_write;
 769         struct page *page;
 770         int wait = 0;
 771         int err;
 772
 773         if (!bitmap)
 774                 return 0;
 775
 776         /* look at each page to see if there are any set bits that need to be
 777          * flushed out to disk */
 778         for (i = 0; i < bitmap->file_pages; i++) {
 779                 spin_lock_irqsave(&bitmap->lock, flags);
 780                 if (!bitmap->filemap) {
 781                         spin_unlock_irqrestore(&bitmap->lock, flags);
 782                         return 0;
 783                 }
 784                 page = bitmap->filemap[i];
 785                 dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
 786                 need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
 787                 clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
 788                 clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
 789                 if (dirty)
 790                         wait = 1;
 791                 spin_unlock_irqrestore(&bitmap->lock, flags);
 792
 793                 if (dirty | need_write)
 794                         err = write_page(bitmap, page, 0);
 795         }
 796         if (wait) { /* if any writes were performed, we need to wait on them */
 797                 if (bitmap->file)
 798                         wait_event(bitmap->write_wait,
 799                                    atomic_read(&bitmap->pending_writes)==0);
 800                 else
 801                         md_super_wait(bitmap->mddev);
 802         }
 803         if (bitmap->flags & BITMAP_WRITE_ERROR)
 804                 bitmap_file_kick(bitmap);
 805         return 0;
 806 }
 807
 808 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
 809 /* * bitmap_init_from_disk -- called at bitmap_create time to initialize
 810  * the in-memory bitmap from the on-disk bitmap -- also, sets up the
 811  * memory mapping of the bitmap file
 812  * Special cases:
 813  *   if there's no bitmap file, or if the bitmap file had been
 814  *   previously kicked from the array, we mark all the bits as
 815  *   1's in order to cause a full resync.
 816  *
 817  * We ignore all bits for sectors that end earlier than 'start'.
 818  * This is used when reading an out-of-date bitmap...
 819  */
 820 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
 821 {
 822         unsigned long i, chunks, index, oldindex, bit;
 823         struct page *page = NULL, *oldpage = NULL;
 824         unsigned long num_pages, bit_cnt = 0;
 825         struct file *file;
 826         unsigned long bytes, offset;
 827         int outofdate;
 828         int ret = -ENOSPC;
 829         void *paddr;
 830
 831         chunks = bitmap->chunks;
 832         file = bitmap->file;
 833
 834         BUG_ON(!file && !bitmap->offset);
 835
 836 #ifdef INJECT_FAULTS_3
 837         outofdate = 1;
 838 #else
 839         outofdate = bitmap->flags & BITMAP_STALE;
 840 #endif
 841         if (outofdate)
 842                 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
 843                         "recovery\n", bmname(bitmap));
 844
 845         bytes = (chunks + 7) / 8;
 846
 847         num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE;
 848
 849         if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
 850                 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
 851                         bmname(bitmap),
 852                         (unsigned long) i_size_read(file->f_mapping->host),
 853                         bytes + sizeof(bitmap_super_t));
 854                 goto out;
 855         }
 856
 857         ret = -ENOMEM;
 858
 859         bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
 860         if (!bitmap->filemap)
 861                 goto out;
 862
 863         /* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
 864         bitmap->filemap_attr = kzalloc(
 865                 (((num_pages*4/8)+sizeof(unsigned long)-1)
 866                  /sizeof(unsigned long))
 867                 *sizeof(unsigned long),
 868                 GFP_KERNEL);
 869         if (!bitmap->filemap_attr)
 870                 goto out;
 871
 872         oldindex = ~0L;
 873
 874         for (i = 0; i < chunks; i++) {
 875                 int b;
 876                 index = file_page_index(i);
 877                 bit = file_page_offset(i);
 878                 if (index != oldindex) { /* this is a new page, read it in */
 879                         int count;
 880                         /* unmap the old page, we're done with it */
 881                         if (index == num_pages-1)
 882                                 count = bytes - index * PAGE_SIZE;
 883                         else
 884                                 count = PAGE_SIZE;
 885                         if (index == 0) {
 886                                 /*
 887                                  * if we're here then the superblock page
 888                                  * contains some bits (PAGE_SIZE != sizeof sb)
 889                                  * we've already read it in, so just use it
 890                                  */
 891                                 page = bitmap->sb_page;
 892                                 offset = sizeof(bitmap_super_t);
 893                         } else if (file) {
 894                                 page = read_page(file, index, bitmap, count);
 895                                 offset = 0;
 896                         } else {
 897                                 page = read_sb_page(bitmap->mddev, bitmap->offset, index);
 898                                 offset = 0;
 899                         }
 900                         if (IS_ERR(page)) { /* read error */
 901                                 ret = PTR_ERR(page);
 902                                 goto out;
 903                         }
 904
 905                         oldindex = index;
 906                         oldpage = page;
 907
 908                         if (outofdate) {
 909                                 /*
 910                                  * if bitmap is out of date, dirty the
 911                                  * whole page and write it out
 912                                  */
 913                                 paddr = kmap_atomic(page, KM_USER0);
 914                                 memset(paddr + offset, 0xff,
 915                                        PAGE_SIZE - offset);
 916                                 kunmap_atomic(paddr, KM_USER0);
 917                                 ret = write_page(bitmap, page, 1);
 918                                 if (ret) {
 919                                         /* release, page not in filemap yet */
 920                                         put_page(page);
 921                                         goto out;
 922                                 }
 923                         }
 924
 925                         bitmap->filemap[bitmap->file_pages++] = page;
 926                 }
 927                 paddr = kmap_atomic(page, KM_USER0);
 928                 if (bitmap->flags & BITMAP_HOSTENDIAN)
 929                         b = test_bit(bit, paddr);
 930                 else
 931                         b = ext2_test_bit(bit, paddr);
 932                 kunmap_atomic(paddr, KM_USER0);
 933                 if (b) {
 934                         /* if the disk bit is set, set the memory bit */
 935                         bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap),
 936                                                ((i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) >= start)
 937                                 );
 938                         bit_cnt++;
 939                         set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
 940                 }
 941         }
 942
 943         /* everything went OK */
 944         ret = 0;
 945         bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
 946
 947         if (bit_cnt) { /* Kick recovery if any bits were set */
 948                 set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
 949                 md_wakeup_thread(bitmap->mddev->thread);
 950         }
 951
 952 out:
 953         printk(KERN_INFO "%s: bitmap initialized from disk: "
 954                 "read %lu/%lu pages, set %lu bits, status: %d\n",
 955                 bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, ret);
 956
 957         return ret;
 958 }
 959
 960 void bitmap_write_all(struct bitmap *bitmap)
 961 {
 962         /* We don't actually write all bitmap blocks here,
 963          * just flag them as needing to be written
 964          */
 965         int i;
 966
 967         for (i=0; i < bitmap->file_pages; i++)
 968                 set_page_attr(bitmap, bitmap->filemap[i],
 969                               BITMAP_PAGE_NEEDWRITE);
 970 }
 971
 972
 973 static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
 974 {
 975         sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
 976         unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
 977         bitmap->bp[page].count += inc;
 978 /*
 979         if (page == 0) printk("count page 0, offset %llu: %d gives %d\n",
 980                               (unsigned long long)offset, inc, bitmap->bp[page].count);
 981 */
 982         bitmap_checkfree(bitmap, page);
 983 }
 984 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
 985                                             sector_t offset, int *blocks,
 986                                             int create);
 987
 988 /*
 989  * bitmap daemon -- periodically wakes up to clean bits and flush pages
 990  *                      out to disk
 991  */
 992
 993 int bitmap_daemon_work(struct bitmap *bitmap)
 994 {
 995         unsigned long j;
 996         unsigned long flags;
 997         struct page *page = NULL, *lastpage = NULL;
 998         int err = 0;
 999         int blocks;
1000         void *paddr;
1001
1002         if (bitmap == NULL)
1003                 return 0;
1004         if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ))
1005                 return 0;
1006         bitmap->daemon_lastrun = jiffies;
1007
1008         for (j = 0; j < bitmap->chunks; j++) {
1009                 bitmap_counter_t *bmc;
1010                 spin_lock_irqsave(&bitmap->lock, flags);
1011                 if (!bitmap->filemap) {
1012                         /* error or shutdown */
1013                         spin_unlock_irqrestore(&bitmap->lock, flags);
1014                         break;
1015                 }
1016
1017                 page = filemap_get_page(bitmap, j);
1018
1019                 if (page != lastpage) {
1020                         /* skip this page unless it's marked as needing cleaning */
1021                         if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
1022                                 int need_write = test_page_attr(bitmap, page,
1023                                                                 BITMAP_PAGE_NEEDWRITE);
1024                                 if (need_write)
1025                                         clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1026
1027                                 spin_unlock_irqrestore(&bitmap->lock, flags);
1028                                 if (need_write) {
1029                                         switch (write_page(bitmap, page, 0)) {
1030                                         case 0:
1031                                                 break;
1032                                         default:
1033                                                 bitmap_file_kick(bitmap);
1034                                         }
1035                                 }
1036                                 continue;
1037                         }
1038
1039                         /* grab the new page, sync and release the old */
1040                         if (lastpage != NULL) {
1041                                 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1042                                         clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1043                                         spin_unlock_irqrestore(&bitmap->lock, flags);
1044                                         err = write_page(bitmap, lastpage, 0);
1045                                 } else {
1046                                         set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1047                                         spin_unlock_irqrestore(&bitmap->lock, flags);
1048                                 }
1049                                 if (err)
1050                                         bitmap_file_kick(bitmap);
1051                         } else
1052                                 spin_unlock_irqrestore(&bitmap->lock, flags);
1053                         lastpage = page;
1054 /*
1055                         printk("bitmap clean at page %lu\n", j);
1056 */
1057                         spin_lock_irqsave(&bitmap->lock, flags);
1058                         clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1059                 }
1060                 bmc = bitmap_get_counter(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1061                                         &blocks, 0);
1062                 if (bmc) {
1063 /*
1064   if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc);
1065 */
1066                         if (*bmc == 2) {
1067                                 *bmc=1; /* maybe clear the bit next time */
1068                                 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1069                         } else if (*bmc == 1) {
1070                                 /* we can clear the bit */
1071                                 *bmc = 0;
1072                                 bitmap_count_page(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
1073                                                   -1);
1074
1075                                 /* clear the bit */
1076                                 paddr = kmap_atomic(page, KM_USER0);
1077                                 if (bitmap->flags & BITMAP_HOSTENDIAN)
1078                                         clear_bit(file_page_offset(j), paddr);
1079                                 else
1080                                         ext2_clear_bit(file_page_offset(j), paddr);
1081                                 kunmap_atomic(paddr, KM_USER0);
1082                         }
1083                 }
1084                 spin_unlock_irqrestore(&bitmap->lock, flags);
1085         }
1086
1087         /* now sync the final page */
1088         if (lastpage != NULL) {
1089                 spin_lock_irqsave(&bitmap->lock, flags);
1090                 if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1091                         clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1092                         spin_unlock_irqrestore(&bitmap->lock, flags);
1093                         err = write_page(bitmap, lastpage, 0);
1094                 } else {
1095                         set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1096                         spin_unlock_irqrestore(&bitmap->lock, flags);
1097                 }
1098         }
1099
1100         return err;
1101 }
1102
1103 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1104                                             sector_t offset, int *blocks,
1105                                             int create)
1106 {
1107         /* If 'create', we might release the lock and reclaim it.
1108          * The lock must have been taken with interrupts enabled.
1109          * If !create, we don't release the lock.
1110          */
1111         sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1112         unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1113         unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1114         sector_t csize;
1115
1116         if (bitmap_checkpage(bitmap, page, create) < 0) {
1117                 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1118                 *blocks = csize - (offset & (csize- 1));
1119                 return NULL;
1120         }
1121         /* now locked ... */
1122
1123         if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1124                 /* should we use the first or second counter field
1125                  * of the hijacked pointer? */
1126                 int hi = (pageoff > PAGE_COUNTER_MASK);
1127                 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) +
1128                                           PAGE_COUNTER_SHIFT - 1);
1129                 *blocks = csize - (offset & (csize- 1));
1130                 return  &((bitmap_counter_t *)
1131                           &bitmap->bp[page].map)[hi];
1132         } else { /* page is allocated */
1133                 csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1134                 *blocks = csize - (offset & (csize- 1));
1135                 return (bitmap_counter_t *)
1136                         &(bitmap->bp[page].map[pageoff]);
1137         }
1138 }
1139
1140 int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1141 {
1142         if (!bitmap) return 0;
1143
1144         if (behind) {
1145                 atomic_inc(&bitmap->behind_writes);
1146                 PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n",
1147                   atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
1148         }
1149
1150         while (sectors) {
1151                 int blocks;
1152                 bitmap_counter_t *bmc;
1153
1154                 spin_lock_irq(&bitmap->lock);
1155                 bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
1156                 if (!bmc) {
1157                         spin_unlock_irq(&bitmap->lock);
1158                         return 0;
1159                 }
1160
1161                 switch(*bmc) {
1162                 case 0:
1163                         bitmap_file_set_bit(bitmap, offset);
1164                         bitmap_count_page(bitmap,offset, 1);
1165                         blk_plug_device(bitmap->mddev->queue);
1166                         /* fall through */
1167                 case 1:
1168                         *bmc = 2;
1169                 }
1170                 BUG_ON((*bmc & COUNTER_MAX) == COUNTER_MAX);
1171                 (*bmc)++;
1172
1173                 spin_unlock_irq(&bitmap->lock);
1174
1175                 offset += blocks;
1176                 if (sectors > blocks)
1177                         sectors -= blocks;
1178                 else sectors = 0;
1179         }
1180         return 0;
1181 }
1182
1183 void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1184                      int success, int behind)
1185 {
1186         if (!bitmap) return;
1187         if (behind) {
1188                 atomic_dec(&bitmap->behind_writes);
1189                 PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n",
1190                   atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
1191         }
1192
1193         while (sectors) {
1194                 int blocks;
1195                 unsigned long flags;
1196                 bitmap_counter_t *bmc;
1197
1198                 spin_lock_irqsave(&bitmap->lock, flags);
1199                 bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
1200                 if (!bmc) {
1201                         spin_unlock_irqrestore(&bitmap->lock, flags);
1202                         return;
1203                 }
1204
1205                 if (!success && ! (*bmc & NEEDED_MASK))
1206                         *bmc |= NEEDED_MASK;
1207
1208                 (*bmc)--;
1209                 if (*bmc <= 2) {
1210                         set_page_attr(bitmap,
1211                                       filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1212                                       BITMAP_PAGE_CLEAN);
1213                 }
1214                 spin_unlock_irqrestore(&bitmap->lock, flags);
1215                 offset += blocks;
1216                 if (sectors > blocks)
1217                         sectors -= blocks;
1218                 else sectors = 0;
1219         }
1220 }
1221
1222 int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks,
1223                         int degraded)
1224 {
1225         bitmap_counter_t *bmc;
1226         int rv;
1227         if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1228                 *blocks = 1024;
1229                 return 1; /* always resync if no bitmap */
1230         }
1231         spin_lock_irq(&bitmap->lock);
1232         bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1233         rv = 0;
1234         if (bmc) {
1235                 /* locked */
1236                 if (RESYNC(*bmc))
1237                         rv = 1;
1238                 else if (NEEDED(*bmc)) {
1239                         rv = 1;
1240                         if (!degraded) { /* don't set/clear bits if degraded */
1241                                 *bmc |= RESYNC_MASK;
1242                                 *bmc &= ~NEEDED_MASK;
1243                         }
1244                 }
1245         }
1246         spin_unlock_irq(&bitmap->lock);
1247         return rv;
1248 }
1249
1250 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted)
1251 {
1252         bitmap_counter_t *bmc;
1253         unsigned long flags;
1254 /*
1255         if (offset == 0) printk("bitmap_end_sync 0 (%d)\n", aborted);
1256 */      if (bitmap == NULL) {
1257                 *blocks = 1024;
1258                 return;
1259         }
1260         spin_lock_irqsave(&bitmap->lock, flags);
1261         bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1262         if (bmc == NULL)
1263                 goto unlock;
1264         /* locked */
1265 /*
1266         if (offset == 0) printk("bitmap_end sync found 0x%x, blocks %d\n", *bmc, *blocks);
1267 */
1268         if (RESYNC(*bmc)) {
1269                 *bmc &= ~RESYNC_MASK;
1270
1271                 if (!NEEDED(*bmc) && aborted)
1272                         *bmc |= NEEDED_MASK;
1273                 else {
1274                         if (*bmc <= 2) {
1275                                 set_page_attr(bitmap,
1276                                               filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1277                                               BITMAP_PAGE_CLEAN);
1278                         }
1279                 }
1280         }
1281  unlock:
1282         spin_unlock_irqrestore(&bitmap->lock, flags);
1283 }
1284
1285 void bitmap_close_sync(struct bitmap *bitmap)
1286 {
1287         /* Sync has finished, and any bitmap chunks that weren't synced
1288          * properly have been aborted.  It remains to us to clear the
1289          * RESYNC bit wherever it is still on
1290          */
1291         sector_t sector = 0;
1292         int blocks;
1293         if (!bitmap) return;
1294         while (sector < bitmap->mddev->resync_max_sectors) {
1295                 bitmap_end_sync(bitmap, sector, &blocks, 0);
1296 /*
1297                 if (sector < 500) printk("bitmap_close_sync: sec %llu blks %d\n",
1298                                          (unsigned long long)sector, blocks);
1299 */              sector += blocks;
1300         }
1301 }
1302
1303 static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1304 {
1305         /* For each chunk covered by any of these sectors, set the
1306          * counter to 1 and set resync_needed.  They should all
1307          * be 0 at this point
1308          */
1309
1310         int secs;
1311         bitmap_counter_t *bmc;
1312         spin_lock_irq(&bitmap->lock);
1313         bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
1314         if (!bmc) {
1315                 spin_unlock_irq(&bitmap->lock);
1316                 return;
1317         }
1318         if (! *bmc) {
1319                 struct page *page;
1320                 *bmc = 1 | (needed?NEEDED_MASK:0);
1321                 bitmap_count_page(bitmap, offset, 1);
1322                 page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
1323                 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1324         }
1325         spin_unlock_irq(&bitmap->lock);
1326
1327 }
1328
1329 /*
1330  * flush out any pending updates
1331  */
1332 void bitmap_flush(mddev_t *mddev)
1333 {
1334         struct bitmap *bitmap = mddev->bitmap;
1335         int sleep;
1336
1337         if (!bitmap) /* there was no bitmap */
1338                 return;
1339
1340         /* run the daemon_work three time to ensure everything is flushed
1341          * that can be
1342          */
1343         sleep = bitmap->daemon_sleep;
1344         bitmap->daemon_sleep = 0;
1345         bitmap_daemon_work(bitmap);
1346         bitmap_daemon_work(bitmap);
1347         bitmap_daemon_work(bitmap);
1348         bitmap->daemon_sleep = sleep;
1349         bitmap_update_sb(bitmap);
1350 }
1351
1352 /*
1353  * free memory that was allocated
1354  */
1355 static void bitmap_free(struct bitmap *bitmap)
1356 {
1357         unsigned long k, pages;
1358         struct bitmap_page *bp;
1359
1360         if (!bitmap) /* there was no bitmap */
1361                 return;
1362
1363         /* release the bitmap file and kill the daemon */
1364         bitmap_file_put(bitmap);
1365
1366         bp = bitmap->bp;
1367         pages = bitmap->pages;
1368
1369         /* free all allocated memory */
1370
1371         if (bp) /* deallocate the page memory */
1372                 for (k = 0; k < pages; k++)
1373                         if (bp[k].map && !bp[k].hijacked)
1374                                 kfree(bp[k].map);
1375         kfree(bp);
1376         kfree(bitmap);
1377 }
1378 void bitmap_destroy(mddev_t *mddev)
1379 {
1380         struct bitmap *bitmap = mddev->bitmap;
1381
1382         if (!bitmap) /* there was no bitmap */
1383                 return;
1384
1385         mddev->bitmap = NULL; /* disconnect from the md device */
1386         if (mddev->thread)
1387                 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1388
1389         bitmap_free(bitmap);
1390 }
1391
1392 /*
1393  * initialize the bitmap structure
1394  * if this returns an error, bitmap_destroy must be called to do clean up
1395  */
1396 int bitmap_create(mddev_t *mddev)
1397 {
1398         struct bitmap *bitmap;
1399         unsigned long blocks = mddev->resync_max_sectors;
1400         unsigned long chunks;
1401         unsigned long pages;
1402         struct file *file = mddev->bitmap_file;
1403         int err;
1404         sector_t start;
1405
1406         BUG_ON(sizeof(bitmap_super_t) != 256);
1407
1408         if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */
1409                 return 0;
1410
1411         BUG_ON(file && mddev->bitmap_offset);
1412
1413         bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1414         if (!bitmap)
1415                 return -ENOMEM;
1416
1417         spin_lock_init(&bitmap->lock);
1418         bitmap->mddev = mddev;
1419
1420         bitmap->file = file;
1421         bitmap->offset = mddev->bitmap_offset;
1422         if (file) get_file(file);
1423
1424         /* Ensure we read fresh data */
1425         invalidate_inode_pages(file->f_dentry->d_inode->i_mapping);
1426
1427         /* read superblock from bitmap file (this sets bitmap->chunksize) */
1428         err = bitmap_read_sb(bitmap);
1429         if (err)
1430                 goto error;
1431
1432         bitmap->chunkshift = find_first_bit(&bitmap->chunksize,
1433                                         sizeof(bitmap->chunksize));
1434
1435         /* now that chunksize and chunkshift are set, we can use these macros */
1436         chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) /
1437                         CHUNK_BLOCK_RATIO(bitmap);
1438         pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1439
1440         BUG_ON(!pages);
1441
1442         bitmap->chunks = chunks;
1443         bitmap->pages = pages;
1444         bitmap->missing_pages = pages;
1445         bitmap->counter_bits = COUNTER_BITS;
1446
1447         bitmap->syncchunk = ~0UL;
1448
1449         atomic_set(&bitmap->pending_writes, 0);
1450         init_waitqueue_head(&bitmap->write_wait);
1451
1452 #ifdef INJECT_FATAL_FAULT_1
1453         bitmap->bp = NULL;
1454 #else
1455         bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1456 #endif
1457         err = -ENOMEM;
1458         if (!bitmap->bp)
1459                 goto error;
1460
1461         /* now that we have some pages available, initialize the in-memory
1462          * bitmap from the on-disk bitmap */
1463         start = 0;
1464         if (mddev->degraded == 0
1465             || bitmap->events_cleared == mddev->events)
1466                 /* no need to keep dirty bits to optimise a re-add of a missing device */
1467                 start = mddev->recovery_cp;
1468         err = bitmap_init_from_disk(bitmap, start);
1469
1470         if (err)
1471                 goto error;
1472
1473         printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1474                 pages, bmname(bitmap));
1475
1476         mddev->bitmap = bitmap;
1477
1478         mddev->thread->timeout = bitmap->daemon_sleep * HZ;
1479
1480         return bitmap_update_sb(bitmap);
1481
1482  error:
1483         bitmap_free(bitmap);
1484         return err;
1485 }
1486
1487 /* the bitmap API -- for raid personalities */
1488 EXPORT_SYMBOL(bitmap_startwrite);
1489 EXPORT_SYMBOL(bitmap_endwrite);
1490 EXPORT_SYMBOL(bitmap_start_sync);
1491 EXPORT_SYMBOL(bitmap_end_sync);
1492 EXPORT_SYMBOL(bitmap_unplug);
1493 EXPORT_SYMBOL(bitmap_close_sync);