1/*
   2 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
   3 *
   4 * bitmap_create  - sets up the bitmap structure
   5 * bitmap_destroy - destroys the bitmap structure
   6 *
   7 * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
   8 * - added disk storage for bitmap
   9 * - changes to allow various bitmap chunk sizes
  10 */
  11
  12/*
  13 * Still to do:
  14 *
  15 * flush after percent set rather than just time based. (maybe both).
  16 */
  17
  18#include <linux/blkdev.h>
  19#include <linux/module.h>
  20#include <linux/errno.h>
  21#include <linux/slab.h>
  22#include <linux/init.h>
  23#include <linux/timer.h>
  24#include <linux/sched.h>
  25#include <linux/list.h>
  26#include <linux/file.h>
  27#include <linux/mount.h>
  28#include <linux/buffer_head.h>
 
  29#include "md.h"
  30#include "bitmap.h"
  31
  32/* debug macros */
  33
  34#define DEBUG 0
  35
  36#if DEBUG
  37/* these are for debugging purposes only! */
  38
  39/* define one and only one of these */
  40#define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */
  41#define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/
  42#define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */
  43#define INJECT_FAULTS_4 0 /* undef */
  44#define INJECT_FAULTS_5 0 /* undef */
  45#define INJECT_FAULTS_6 0
  46
  47/* if these are defined, the driver will fail! debug only */
  48#define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */
  49#define INJECT_FATAL_FAULT_2 0 /* undef */
  50#define INJECT_FATAL_FAULT_3 0 /* undef */
  51#endif
  52
  53#ifndef PRINTK
  54#  if DEBUG > 0
  55#    define PRINTK(x...) printk(KERN_DEBUG x)
  56#  else
  57#    define PRINTK(x...)
  58#  endif
  59#endif
  60
  61static inline char *bmname(struct bitmap *bitmap)
  62{
  63	return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
  64}
  65
  66/*
  67 * just a placeholder - calls kmalloc for bitmap pages
  68 */
  69static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
  70{
  71	unsigned char *page;
  72
  73#ifdef INJECT_FAULTS_1
  74	page = NULL;
  75#else
  76	page = kzalloc(PAGE_SIZE, GFP_NOIO);
  77#endif
  78	if (!page)
  79		printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
  80	else
  81		PRINTK("%s: bitmap_alloc_page: allocated page at %p\n",
  82			bmname(bitmap), page);
  83	return page;
  84}
  85
  86/*
  87 * for now just a placeholder -- just calls kfree for bitmap pages
  88 */
  89static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page)
  90{
  91	PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page);
  92	kfree(page);
  93}
  94
  95/*
  96 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
  97 *
  98 * 1) check to see if this page is allocated, if it's not then try to alloc
  99 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
 100 *    page pointer directly as a counter
 101 *
 102 * if we find our page, we increment the page's refcount so that it stays
 103 * allocated while we're using it
 104 */
 105static int bitmap_checkpage(struct bitmap *bitmap,
 106			    unsigned long page, int create)
 107__releases(bitmap->lock)
 108__acquires(bitmap->lock)
 109{
 110	unsigned char *mappage;
 111
 112	if (page >= bitmap->pages) {
 113		/* This can happen if bitmap_start_sync goes beyond
 114		 * End-of-device while looking for a whole page.
 115		 * It is harmless.
 116		 */
 117		return -EINVAL;
 118	}
 119
 120	if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
 121		return 0;
 122
 123	if (bitmap->bp[page].map) /* page is already allocated, just return */
 124		return 0;
 125
 126	if (!create)
 127		return -ENOENT;
 128
 129	/* this page has not been allocated yet */
 130
 131	spin_unlock_irq(&bitmap->lock);
 132	mappage = bitmap_alloc_page(bitmap);
 133	spin_lock_irq(&bitmap->lock);
 134
 135	if (mappage == 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		if (!bitmap->bp[page].map)
 141			bitmap->bp[page].hijacked = 1;
 142	} else if (bitmap->bp[page].map ||
 143		   bitmap->bp[page].hijacked) {
 144		/* somebody beat us to getting the page */
 145		bitmap_free_page(bitmap, mappage);
 146		return 0;
 147	} else {
 148
 149		/* no page was in place and we have one, so install it */
 150
 151		bitmap->bp[page].map = mappage;
 152		bitmap->missing_pages--;
 153	}
 154	return 0;
 155}
 156
 157/* if page is completely empty, put it back on the free list, or dealloc it */
 158/* if page was hijacked, unmark the flag so it might get alloced next time */
 159/* Note: lock should be held when calling this */
 160static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
 161{
 162	char *ptr;
 163
 164	if (bitmap->bp[page].count) /* page is still busy */
 165		return;
 166
 167	/* page is no longer in use, it can be released */
 168
 169	if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
 170		bitmap->bp[page].hijacked = 0;
 171		bitmap->bp[page].map = NULL;
 172	} else {
 173		/* normal case, free the page */
 174		ptr = bitmap->bp[page].map;
 175		bitmap->bp[page].map = NULL;
 176		bitmap->missing_pages++;
 177		bitmap_free_page(bitmap, ptr);
 178	}
 179}
 180
 181/*
 182 * bitmap file handling - read and write the bitmap file and its superblock
 183 */
 184
 185/*
 186 * basic page I/O operations
 187 */
 188
 189/* IO operations when bitmap is stored near all superblocks */
 190static struct page *read_sb_page(mddev_t *mddev, loff_t offset,
 191				 struct page *page,
 192				 unsigned long index, int size)
 193{
 194	/* choose a good rdev and read the page from there */
 195
 196	mdk_rdev_t *rdev;
 197	sector_t target;
 198	int did_alloc = 0;
 199
 200	if (!page) {
 201		page = alloc_page(GFP_KERNEL);
 202		if (!page)
 203			return ERR_PTR(-ENOMEM);
 204		did_alloc = 1;
 205	}
 206
 207	list_for_each_entry(rdev, &mddev->disks, same_set) {
 208		if (! test_bit(In_sync, &rdev->flags)
 209		    || test_bit(Faulty, &rdev->flags))
 210			continue;
 211
 212		target = offset + index * (PAGE_SIZE/512);
 213
 214		if (sync_page_io(rdev, target,
 215				 roundup(size, bdev_logical_block_size(rdev->bdev)),
 216				 page, READ, true)) {
 217			page->index = index;
 218			attach_page_buffers(page, NULL); /* so that free_buffer will
 219							  * quietly no-op */
 220			return page;
 221		}
 222	}
 223	if (did_alloc)
 224		put_page(page);
 225	return ERR_PTR(-EIO);
 226
 227}
 228
 229static mdk_rdev_t *next_active_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
 230{
 231	/* Iterate the disks of an mddev, using rcu to protect access to the
 232	 * linked list, and raising the refcount of devices we return to ensure
 233	 * they don't disappear while in use.
 234	 * As devices are only added or removed when raid_disk is < 0 and
 235	 * nr_pending is 0 and In_sync is clear, the entries we return will
 236	 * still be in the same position on the list when we re-enter
 237	 * list_for_each_continue_rcu.
 238	 */
 239	struct list_head *pos;
 240	rcu_read_lock();
 241	if (rdev == NULL)
 242		/* start at the beginning */
 243		pos = &mddev->disks;
 244	else {
 245		/* release the previous rdev and start from there. */
 246		rdev_dec_pending(rdev, mddev);
 247		pos = &rdev->same_set;
 248	}
 249	list_for_each_continue_rcu(pos, &mddev->disks) {
 250		rdev = list_entry(pos, mdk_rdev_t, same_set);
 251		if (rdev->raid_disk >= 0 &&
 252		    !test_bit(Faulty, &rdev->flags)) {
 253			/* this is a usable devices */
 254			atomic_inc(&rdev->nr_pending);
 255			rcu_read_unlock();
 256			return rdev;
 257		}
 258	}
 259	rcu_read_unlock();
 260	return NULL;
 261}
 262
 263static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
 264{
 265	mdk_rdev_t *rdev = NULL;
 266	struct block_device *bdev;
 267	mddev_t *mddev = bitmap->mddev;
 
 268
 269	while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
 270		int size = PAGE_SIZE;
 271		loff_t offset = mddev->bitmap_info.offset;
 272
 273		bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
 274
 275		if (page->index == bitmap->file_pages-1)
 276			size = roundup(bitmap->last_page_size,
 
 
 
 277				       bdev_logical_block_size(bdev));
 
 278		/* Just make sure we aren't corrupting data or
 279		 * metadata
 280		 */
 281		if (mddev->external) {
 282			/* Bitmap could be anywhere. */
 283			if (rdev->sb_start + offset + (page->index
 284						       * (PAGE_SIZE/512))
 285			    > rdev->data_offset
 286			    &&
 287			    rdev->sb_start + offset
 288			    < (rdev->data_offset + mddev->dev_sectors
 289			     + (PAGE_SIZE/512)))
 290				goto bad_alignment;
 291		} else if (offset < 0) {
 292			/* DATA  BITMAP METADATA  */
 293			if (offset
 294			    + (long)(page->index * (PAGE_SIZE/512))
 295			    + size/512 > 0)
 296				/* bitmap runs in to metadata */
 297				goto bad_alignment;
 298			if (rdev->data_offset + mddev->dev_sectors
 299			    > rdev->sb_start + offset)
 300				/* data runs in to bitmap */
 301				goto bad_alignment;
 302		} else if (rdev->sb_start < rdev->data_offset) {
 303			/* METADATA BITMAP DATA */
 304			if (rdev->sb_start
 305			    + offset
 306			    + page->index*(PAGE_SIZE/512) + size/512
 307			    > rdev->data_offset)
 308				/* bitmap runs in to data */
 309				goto bad_alignment;
 310		} else {
 311			/* DATA METADATA BITMAP - no problems */
 312		}
 313		md_super_write(mddev, rdev,
 314			       rdev->sb_start + offset
 315			       + page->index * (PAGE_SIZE/512),
 316			       size,
 317			       page);
 318	}
 319
 320	if (wait)
 321		md_super_wait(mddev);
 322	return 0;
 323
 324 bad_alignment:
 325	return -EINVAL;
 326}
 327
 328static void bitmap_file_kick(struct bitmap *bitmap);
 329/*
 330 * write out a page to a file
 331 */
 332static void write_page(struct bitmap *bitmap, struct page *page, int wait)
 333{
 334	struct buffer_head *bh;
 335
 336	if (bitmap->file == NULL) {
 337		switch (write_sb_page(bitmap, page, wait)) {
 338		case -EINVAL:
 339			bitmap->flags |= BITMAP_WRITE_ERROR;
 340		}
 341	} else {
 342
 343		bh = page_buffers(page);
 344
 345		while (bh && bh->b_blocknr) {
 346			atomic_inc(&bitmap->pending_writes);
 347			set_buffer_locked(bh);
 348			set_buffer_mapped(bh);
 349			submit_bh(WRITE | REQ_SYNC, bh);
 350			bh = bh->b_this_page;
 351		}
 352
 353		if (wait)
 354			wait_event(bitmap->write_wait,
 355				   atomic_read(&bitmap->pending_writes)==0);
 356	}
 357	if (bitmap->flags & BITMAP_WRITE_ERROR)
 358		bitmap_file_kick(bitmap);
 359}
 360
 361static void end_bitmap_write(struct buffer_head *bh, int uptodate)
 362{
 363	struct bitmap *bitmap = bh->b_private;
 364	unsigned long flags;
 365
 366	if (!uptodate) {
 367		spin_lock_irqsave(&bitmap->lock, flags);
 368		bitmap->flags |= BITMAP_WRITE_ERROR;
 369		spin_unlock_irqrestore(&bitmap->lock, flags);
 370	}
 371	if (atomic_dec_and_test(&bitmap->pending_writes))
 372		wake_up(&bitmap->write_wait);
 373}
 374
 375/* copied from buffer.c */
 376static void
 377__clear_page_buffers(struct page *page)
 378{
 379	ClearPagePrivate(page);
 380	set_page_private(page, 0);
 381	page_cache_release(page);
 382}
 383static void free_buffers(struct page *page)
 384{
 385	struct buffer_head *bh = page_buffers(page);
 
 
 
 386
 
 387	while (bh) {
 388		struct buffer_head *next = bh->b_this_page;
 389		free_buffer_head(bh);
 390		bh = next;
 391	}
 392	__clear_page_buffers(page);
 393	put_page(page);
 394}
 395
 396/* read a page from a file.
 397 * We both read the page, and attach buffers to the page to record the
 398 * address of each block (using bmap).  These addresses will be used
 399 * to write the block later, completely bypassing the filesystem.
 400 * This usage is similar to how swap files are handled, and allows us
 401 * to write to a file with no concerns of memory allocation failing.
 402 */
 403static struct page *read_page(struct file *file, unsigned long index,
 404			      struct bitmap *bitmap,
 405			      unsigned long count)
 
 406{
 407	struct page *page = NULL;
 408	struct inode *inode = file->f_path.dentry->d_inode;
 409	struct buffer_head *bh;
 410	sector_t block;
 411
 412	PRINTK("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
 413			(unsigned long long)index << PAGE_SHIFT);
 414
 415	page = alloc_page(GFP_KERNEL);
 416	if (!page)
 417		page = ERR_PTR(-ENOMEM);
 418	if (IS_ERR(page))
 419		goto out;
 420
 421	bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
 422	if (!bh) {
 423		put_page(page);
 424		page = ERR_PTR(-ENOMEM);
 425		goto out;
 426	}
 427	attach_page_buffers(page, bh);
 428	block = index << (PAGE_SHIFT - inode->i_blkbits);
 429	while (bh) {
 430		if (count == 0)
 431			bh->b_blocknr = 0;
 432		else {
 433			bh->b_blocknr = bmap(inode, block);
 434			if (bh->b_blocknr == 0) {
 435				/* Cannot use this file! */
 436				free_buffers(page);
 437				page = ERR_PTR(-EINVAL);
 438				goto out;
 439			}
 440			bh->b_bdev = inode->i_sb->s_bdev;
 441			if (count < (1<<inode->i_blkbits))
 442				count = 0;
 443			else
 444				count -= (1<<inode->i_blkbits);
 445
 446			bh->b_end_io = end_bitmap_write;
 447			bh->b_private = bitmap;
 448			atomic_inc(&bitmap->pending_writes);
 449			set_buffer_locked(bh);
 450			set_buffer_mapped(bh);
 451			submit_bh(READ, bh);
 452		}
 453		block++;
 454		bh = bh->b_this_page;
 455	}
 456	page->index = index;
 457
 458	wait_event(bitmap->write_wait,
 459		   atomic_read(&bitmap->pending_writes)==0);
 460	if (bitmap->flags & BITMAP_WRITE_ERROR) {
 461		free_buffers(page);
 462		page = ERR_PTR(-EIO);
 463	}
 464out:
 465	if (IS_ERR(page))
 466		printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %ld\n",
 467			(int)PAGE_SIZE,
 468			(unsigned long long)index << PAGE_SHIFT,
 469			PTR_ERR(page));
 470	return page;
 471}
 472
 473/*
 474 * bitmap file superblock operations
 475 */
 476
 477/* update the event counter and sync the superblock to disk */
 478void bitmap_update_sb(struct bitmap *bitmap)
 479{
 480	bitmap_super_t *sb;
 481	unsigned long flags;
 482
 483	if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
 484		return;
 485	if (bitmap->mddev->bitmap_info.external)
 486		return;
 487	spin_lock_irqsave(&bitmap->lock, flags);
 488	if (!bitmap->sb_page) { /* no superblock */
 489		spin_unlock_irqrestore(&bitmap->lock, flags);
 490		return;
 491	}
 492	spin_unlock_irqrestore(&bitmap->lock, flags);
 493	sb = kmap_atomic(bitmap->sb_page, KM_USER0);
 494	sb->events = cpu_to_le64(bitmap->mddev->events);
 495	if (bitmap->mddev->events < bitmap->events_cleared)
 496		/* rocking back to read-only */
 497		bitmap->events_cleared = bitmap->mddev->events;
 498	sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
 499	sb->state = cpu_to_le32(bitmap->flags);
 500	/* Just in case these have been changed via sysfs: */
 501	sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
 502	sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
 503	kunmap_atomic(sb, KM_USER0);
 504	write_page(bitmap, bitmap->sb_page, 1);
 
 
 
 
 
 505}
 506
 507/* print out the bitmap file superblock */
 508void bitmap_print_sb(struct bitmap *bitmap)
 509{
 510	bitmap_super_t *sb;
 511
 512	if (!bitmap || !bitmap->sb_page)
 513		return;
 514	sb = kmap_atomic(bitmap->sb_page, KM_USER0);
 515	printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
 516	printk(KERN_DEBUG "         magic: %08x\n", le32_to_cpu(sb->magic));
 517	printk(KERN_DEBUG "       version: %d\n", le32_to_cpu(sb->version));
 518	printk(KERN_DEBUG "          uuid: %08x.%08x.%08x.%08x\n",
 519					*(__u32 *)(sb->uuid+0),
 520					*(__u32 *)(sb->uuid+4),
 521					*(__u32 *)(sb->uuid+8),
 522					*(__u32 *)(sb->uuid+12));
 523	printk(KERN_DEBUG "        events: %llu\n",
 524			(unsigned long long) le64_to_cpu(sb->events));
 525	printk(KERN_DEBUG "events cleared: %llu\n",
 526			(unsigned long long) le64_to_cpu(sb->events_cleared));
 527	printk(KERN_DEBUG "         state: %08x\n", le32_to_cpu(sb->state));
 528	printk(KERN_DEBUG "     chunksize: %d B\n", le32_to_cpu(sb->chunksize));
 529	printk(KERN_DEBUG "  daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
 530	printk(KERN_DEBUG "     sync size: %llu KB\n",
 531			(unsigned long long)le64_to_cpu(sb->sync_size)/2);
 532	printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
 533	kunmap_atomic(sb, KM_USER0);
 534}
 535
 536/*
 537 * bitmap_new_disk_sb
 538 * @bitmap
 539 *
 540 * This function is somewhat the reverse of bitmap_read_sb.  bitmap_read_sb
 541 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
 542 * This function verifies 'bitmap_info' and populates the on-disk bitmap
 543 * structure, which is to be written to disk.
 544 *
 545 * Returns: 0 on success, -Exxx on error
 546 */
 547static int bitmap_new_disk_sb(struct bitmap *bitmap)
 548{
 549	bitmap_super_t *sb;
 550	unsigned long chunksize, daemon_sleep, write_behind;
 551	int err = -EINVAL;
 552
 553	bitmap->sb_page = alloc_page(GFP_KERNEL);
 554	if (IS_ERR(bitmap->sb_page)) {
 555		err = PTR_ERR(bitmap->sb_page);
 556		bitmap->sb_page = NULL;
 557		return err;
 558	}
 559	bitmap->sb_page->index = 0;
 560
 561	sb = kmap_atomic(bitmap->sb_page, KM_USER0);
 562
 563	sb->magic = cpu_to_le32(BITMAP_MAGIC);
 564	sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
 565
 566	chunksize = bitmap->mddev->bitmap_info.chunksize;
 567	BUG_ON(!chunksize);
 568	if (!is_power_of_2(chunksize)) {
 569		kunmap_atomic(sb, KM_USER0);
 570		printk(KERN_ERR "bitmap chunksize not a power of 2\n");
 571		return -EINVAL;
 572	}
 573	sb->chunksize = cpu_to_le32(chunksize);
 574
 575	daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
 576	if (!daemon_sleep ||
 577	    (daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
 578		printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
 579		daemon_sleep = 5 * HZ;
 580	}
 581	sb->daemon_sleep = cpu_to_le32(daemon_sleep);
 582	bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
 583
 584	/*
 585	 * FIXME: write_behind for RAID1.  If not specified, what
 586	 * is a good choice?  We choose COUNTER_MAX / 2 arbitrarily.
 587	 */
 588	write_behind = bitmap->mddev->bitmap_info.max_write_behind;
 589	if (write_behind > COUNTER_MAX)
 590		write_behind = COUNTER_MAX / 2;
 591	sb->write_behind = cpu_to_le32(write_behind);
 592	bitmap->mddev->bitmap_info.max_write_behind = write_behind;
 593
 594	/* keep the array size field of the bitmap superblock up to date */
 595	sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
 596
 597	memcpy(sb->uuid, bitmap->mddev->uuid, 16);
 598
 599	bitmap->flags |= BITMAP_STALE;
 600	sb->state |= cpu_to_le32(BITMAP_STALE);
 601	bitmap->events_cleared = bitmap->mddev->events;
 602	sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
 603
 604	bitmap->flags |= BITMAP_HOSTENDIAN;
 605	sb->version = cpu_to_le32(BITMAP_MAJOR_HOSTENDIAN);
 606
 607	kunmap_atomic(sb, KM_USER0);
 608
 609	return 0;
 610}
 611
 612/* read the superblock from the bitmap file and initialize some bitmap fields */
 613static int bitmap_read_sb(struct bitmap *bitmap)
 614{
 615	char *reason = NULL;
 616	bitmap_super_t *sb;
 617	unsigned long chunksize, daemon_sleep, write_behind;
 618	unsigned long long events;
 
 619	int err = -EINVAL;
 
 620
 
 
 
 
 
 
 
 
 621	/* page 0 is the superblock, read it... */
 622	if (bitmap->file) {
 623		loff_t isize = i_size_read(bitmap->file->f_mapping->host);
 
 
 
 
 
 624		int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
 625
 626		bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
 
 627	} else {
 628		bitmap->sb_page = read_sb_page(bitmap->mddev,
 629					       bitmap->mddev->bitmap_info.offset,
 630					       NULL,
 631					       0, sizeof(bitmap_super_t));
 632	}
 633	if (IS_ERR(bitmap->sb_page)) {
 634		err = PTR_ERR(bitmap->sb_page);
 635		bitmap->sb_page = NULL;
 636		return err;
 637	}
 
 
 638
 639	sb = kmap_atomic(bitmap->sb_page, KM_USER0);
 640
 641	chunksize = le32_to_cpu(sb->chunksize);
 642	daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
 643	write_behind = le32_to_cpu(sb->write_behind);
 
 644
 645	/* verify that the bitmap-specific fields are valid */
 646	if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
 647		reason = "bad magic";
 648	else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
 649		 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
 650		reason = "unrecognized superblock version";
 651	else if (chunksize < 512)
 652		reason = "bitmap chunksize too small";
 653	else if (!is_power_of_2(chunksize))
 654		reason = "bitmap chunksize not a power of 2";
 655	else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
 656		reason = "daemon sleep period out of range";
 657	else if (write_behind > COUNTER_MAX)
 658		reason = "write-behind limit out of range (0 - 16383)";
 659	if (reason) {
 660		printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
 661			bmname(bitmap), reason);
 662		goto out;
 663	}
 664
 665	/* keep the array size field of the bitmap superblock up to date */
 666	sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
 667
 668	if (!bitmap->mddev->persistent)
 669		goto success;
 670
 671	/*
 672	 * if we have a persistent array superblock, compare the
 673	 * bitmap's UUID and event counter to the mddev's
 674	 */
 675	if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
 676		printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n",
 677			bmname(bitmap));
 678		goto out;
 679	}
 680	events = le64_to_cpu(sb->events);
 681	if (events < bitmap->mddev->events) {
 682		printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) "
 683			"-- forcing full recovery\n", bmname(bitmap), events,
 684			(unsigned long long) bitmap->mddev->events);
 685		sb->state |= cpu_to_le32(BITMAP_STALE);
 
 
 686	}
 687success:
 688	/* assign fields using values from superblock */
 689	bitmap->mddev->bitmap_info.chunksize = chunksize;
 690	bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
 691	bitmap->mddev->bitmap_info.max_write_behind = write_behind;
 692	bitmap->flags |= le32_to_cpu(sb->state);
 693	if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
 694		bitmap->flags |= BITMAP_HOSTENDIAN;
 695	bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
 696	if (bitmap->flags & BITMAP_STALE)
 697		bitmap->events_cleared = bitmap->mddev->events;
 698	err = 0;
 699out:
 700	kunmap_atomic(sb, KM_USER0);
 
 
 
 
 
 
 
 
 
 701	if (err)
 702		bitmap_print_sb(bitmap);
 703	return err;
 704}
 705
 706enum bitmap_mask_op {
 707	MASK_SET,
 708	MASK_UNSET
 709};
 710
 711/* record the state of the bitmap in the superblock.  Return the old value */
 712static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
 713			     enum bitmap_mask_op op)
 714{
 715	bitmap_super_t *sb;
 716	unsigned long flags;
 717	int old;
 718
 719	spin_lock_irqsave(&bitmap->lock, flags);
 720	if (!bitmap->sb_page) { /* can't set the state */
 721		spin_unlock_irqrestore(&bitmap->lock, flags);
 722		return 0;
 723	}
 724	spin_unlock_irqrestore(&bitmap->lock, flags);
 725	sb = kmap_atomic(bitmap->sb_page, KM_USER0);
 726	old = le32_to_cpu(sb->state) & bits;
 727	switch (op) {
 728	case MASK_SET:
 729		sb->state |= cpu_to_le32(bits);
 730		bitmap->flags |= bits;
 731		break;
 732	case MASK_UNSET:
 733		sb->state &= cpu_to_le32(~bits);
 734		bitmap->flags &= ~bits;
 735		break;
 736	default:
 737		BUG();
 738	}
 739	kunmap_atomic(sb, KM_USER0);
 740	return old;
 741}
 742
 743/*
 744 * general bitmap file operations
 745 */
 746
 747/*
 748 * on-disk bitmap:
 749 *
 750 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
 751 * file a page at a time. There's a superblock at the start of the file.
 752 */
 753/* calculate the index of the page that contains this bit */
 754static inline unsigned long file_page_index(struct bitmap *bitmap, unsigned long chunk)
 
 755{
 756	if (!bitmap->mddev->bitmap_info.external)
 757		chunk += sizeof(bitmap_super_t) << 3;
 758	return chunk >> PAGE_BIT_SHIFT;
 759}
 760
 761/* calculate the (bit) offset of this bit within a page */
 762static inline unsigned long file_page_offset(struct bitmap *bitmap, unsigned long chunk)
 
 763{
 764	if (!bitmap->mddev->bitmap_info.external)
 765		chunk += sizeof(bitmap_super_t) << 3;
 766	return chunk & (PAGE_BITS - 1);
 767}
 768
 769/*
 770 * return a pointer to the page in the filemap that contains the given bit
 771 *
 772 * this lookup is complicated by the fact that the bitmap sb might be exactly
 773 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
 774 * 0 or page 1
 775 */
 776static inline struct page *filemap_get_page(struct bitmap *bitmap,
 777					    unsigned long chunk)
 778{
 779	if (file_page_index(bitmap, chunk) >= bitmap->file_pages)
 780		return NULL;
 781	return bitmap->filemap[file_page_index(bitmap, chunk)
 782			       - file_page_index(bitmap, 0)];
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 783}
 784
 785static void bitmap_file_unmap(struct bitmap *bitmap)
 786{
 787	struct page **map, *sb_page;
 788	unsigned long *attr;
 789	int pages;
 790	unsigned long flags;
 791
 792	spin_lock_irqsave(&bitmap->lock, flags);
 793	map = bitmap->filemap;
 794	bitmap->filemap = NULL;
 795	attr = bitmap->filemap_attr;
 796	bitmap->filemap_attr = NULL;
 797	pages = bitmap->file_pages;
 798	bitmap->file_pages = 0;
 799	sb_page = bitmap->sb_page;
 800	bitmap->sb_page = NULL;
 801	spin_unlock_irqrestore(&bitmap->lock, flags);
 802
 803	while (pages--)
 804		if (map[pages] != sb_page) /* 0 is sb_page, release it below */
 805			free_buffers(map[pages]);
 806	kfree(map);
 807	kfree(attr);
 808
 809	if (sb_page)
 810		free_buffers(sb_page);
 811}
 812
 813static void bitmap_file_put(struct bitmap *bitmap)
 814{
 815	struct file *file;
 816	unsigned long flags;
 817
 818	spin_lock_irqsave(&bitmap->lock, flags);
 819	file = bitmap->file;
 820	bitmap->file = NULL;
 821	spin_unlock_irqrestore(&bitmap->lock, flags);
 822
 823	if (file)
 824		wait_event(bitmap->write_wait,
 825			   atomic_read(&bitmap->pending_writes)==0);
 826	bitmap_file_unmap(bitmap);
 827
 828	if (file) {
 829		struct inode *inode = file->f_path.dentry->d_inode;
 830		invalidate_mapping_pages(inode->i_mapping, 0, -1);
 831		fput(file);
 832	}
 833}
 834
 835/*
 836 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
 837 * then it is no longer reliable, so we stop using it and we mark the file
 838 * as failed in the superblock
 839 */
 840static void bitmap_file_kick(struct bitmap *bitmap)
 841{
 842	char *path, *ptr = NULL;
 843
 844	if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) {
 845		bitmap_update_sb(bitmap);
 846
 847		if (bitmap->file) {
 848			path = kmalloc(PAGE_SIZE, GFP_KERNEL);
 849			if (path)
 850				ptr = d_path(&bitmap->file->f_path, path,
 851					     PAGE_SIZE);
 852
 853			printk(KERN_ALERT
 854			      "%s: kicking failed bitmap file %s from array!\n",
 855			      bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
 856
 857			kfree(path);
 858		} else
 859			printk(KERN_ALERT
 860			       "%s: disabling internal bitmap due to errors\n",
 861			       bmname(bitmap));
 862	}
 863
 864	bitmap_file_put(bitmap);
 865
 866	return;
 867}
 868
 869enum bitmap_page_attr {
 870	BITMAP_PAGE_DIRTY = 0,     /* there are set bits that need to be synced */
 871	BITMAP_PAGE_CLEAN = 1,     /* there are bits that might need to be cleared */
 
 872	BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
 873};
 874
 875static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
 876				enum bitmap_page_attr attr)
 877{
 878	__set_bit((page->index<<2) + attr, bitmap->filemap_attr);
 879}
 880
 881static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
 882				enum bitmap_page_attr attr)
 883{
 884	__clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
 885}
 886
 887static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
 888					   enum bitmap_page_attr attr)
 889{
 890	return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
 891}
 892
 
 
 
 
 
 
 893/*
 894 * bitmap_file_set_bit -- called before performing a write to the md device
 895 * to set (and eventually sync) a particular bit in the bitmap file
 896 *
 897 * we set the bit immediately, then we record the page number so that
 898 * when an unplug occurs, we can flush the dirty pages out to disk
 899 */
 900static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
 901{
 902	unsigned long bit;
 903	struct page *page;
 904	void *kaddr;
 905	unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
 906
 907	if (!bitmap->filemap)
 908		return;
 909
 910	page = filemap_get_page(bitmap, chunk);
 911	if (!page)
 912		return;
 913	bit = file_page_offset(bitmap, chunk);
 914
 915	/* set the bit */
 916	kaddr = kmap_atomic(page, KM_USER0);
 917	if (bitmap->flags & BITMAP_HOSTENDIAN)
 918		set_bit(bit, kaddr);
 919	else
 920		__set_bit_le(bit, kaddr);
 921	kunmap_atomic(kaddr, KM_USER0);
 922	PRINTK("set file bit %lu page %lu\n", bit, page->index);
 923	/* record page number so it gets flushed to disk when unplug occurs */
 924	set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 925}
 926
 927/* this gets called when the md device is ready to unplug its underlying
 928 * (slave) device queues -- before we let any writes go down, we need to
 929 * sync the dirty pages of the bitmap file to disk */
 930void bitmap_unplug(struct bitmap *bitmap)
 931{
 932	unsigned long i, flags;
 933	int dirty, need_write;
 934	struct page *page;
 935	int wait = 0;
 936
 937	if (!bitmap)
 
 938		return;
 939
 940	/* look at each page to see if there are any set bits that need to be
 941	 * flushed out to disk */
 942	for (i = 0; i < bitmap->file_pages; i++) {
 943		spin_lock_irqsave(&bitmap->lock, flags);
 944		if (!bitmap->filemap) {
 945			spin_unlock_irqrestore(&bitmap->lock, flags);
 946			return;
 
 
 
 
 
 
 947		}
 948		page = bitmap->filemap[i];
 949		dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
 950		need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
 951		clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
 952		clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
 953		if (dirty)
 954			wait = 1;
 955		spin_unlock_irqrestore(&bitmap->lock, flags);
 956
 957		if (dirty || need_write)
 958			write_page(bitmap, page, 0);
 959	}
 960	if (wait) { /* if any writes were performed, we need to wait on them */
 961		if (bitmap->file)
 962			wait_event(bitmap->write_wait,
 963				   atomic_read(&bitmap->pending_writes)==0);
 964		else
 965			md_super_wait(bitmap->mddev);
 966	}
 967	if (bitmap->flags & BITMAP_WRITE_ERROR)
 968		bitmap_file_kick(bitmap);
 969}
 970EXPORT_SYMBOL(bitmap_unplug);
 971
 972static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
 973/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
 974 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
 975 * memory mapping of the bitmap file
 976 * Special cases:
 977 *   if there's no bitmap file, or if the bitmap file had been
 978 *   previously kicked from the array, we mark all the bits as
 979 *   1's in order to cause a full resync.
 980 *
 981 * We ignore all bits for sectors that end earlier than 'start'.
 982 * This is used when reading an out-of-date bitmap...
 983 */
 984static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
 985{
 986	unsigned long i, chunks, index, oldindex, bit;
 987	struct page *page = NULL, *oldpage = NULL;
 988	unsigned long num_pages, bit_cnt = 0;
 989	struct file *file;
 990	unsigned long bytes, offset;
 991	int outofdate;
 992	int ret = -ENOSPC;
 993	void *paddr;
 
 994
 995	chunks = bitmap->chunks;
 996	file = bitmap->file;
 997
 998	BUG_ON(!file && !bitmap->mddev->bitmap_info.offset);
 
 
 
 
 
 
 
 
 
 
 
 
 
 999
1000#ifdef INJECT_FAULTS_3
1001	outofdate = 1;
1002#else
1003	outofdate = bitmap->flags & BITMAP_STALE;
1004#endif
1005	if (outofdate)
1006		printk(KERN_INFO "%s: bitmap file is out of date, doing full "
1007			"recovery\n", bmname(bitmap));
1008
1009	bytes = DIV_ROUND_UP(bitmap->chunks, 8);
1010	if (!bitmap->mddev->bitmap_info.external)
1011		bytes += sizeof(bitmap_super_t);
1012
1013	num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
1014
1015	if (file && i_size_read(file->f_mapping->host) < bytes) {
1016		printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
1017			bmname(bitmap),
1018			(unsigned long) i_size_read(file->f_mapping->host),
1019			bytes);
1020		goto err;
1021	}
1022
1023	ret = -ENOMEM;
1024
1025	bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
1026	if (!bitmap->filemap)
1027		goto err;
1028
1029	/* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
1030	bitmap->filemap_attr = kzalloc(
1031		roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
1032		GFP_KERNEL);
1033	if (!bitmap->filemap_attr)
1034		goto err;
1035
1036	oldindex = ~0L;
 
 
 
1037
1038	for (i = 0; i < chunks; i++) {
1039		int b;
1040		index = file_page_index(bitmap, i);
1041		bit = file_page_offset(bitmap, i);
1042		if (index != oldindex) { /* this is a new page, read it in */
1043			int count;
1044			/* unmap the old page, we're done with it */
1045			if (index == num_pages-1)
1046				count = bytes - index * PAGE_SIZE;
1047			else
1048				count = PAGE_SIZE;
1049			if (index == 0 && bitmap->sb_page) {
1050				/*
1051				 * if we're here then the superblock page
1052				 * contains some bits (PAGE_SIZE != sizeof sb)
1053				 * we've already read it in, so just use it
1054				 */
1055				page = bitmap->sb_page;
1056				offset = sizeof(bitmap_super_t);
1057				if (!file)
1058					page = read_sb_page(
1059						bitmap->mddev,
1060						bitmap->mddev->bitmap_info.offset,
1061						page,
1062						index, count);
1063			} else if (file) {
1064				page = read_page(file, index, bitmap, count);
1065				offset = 0;
1066			} else {
1067				page = read_sb_page(bitmap->mddev,
1068						    bitmap->mddev->bitmap_info.offset,
1069						    NULL,
1070						    index, count);
1071				offset = 0;
1072			}
1073			if (IS_ERR(page)) { /* read error */
1074				ret = PTR_ERR(page);
1075				goto err;
1076			}
1077
1078			oldindex = index;
1079			oldpage = page;
1080
1081			bitmap->filemap[bitmap->file_pages++] = page;
1082			bitmap->last_page_size = count;
1083
1084			if (outofdate) {
1085				/*
1086				 * if bitmap is out of date, dirty the
1087				 * whole page and write it out
1088				 */
1089				paddr = kmap_atomic(page, KM_USER0);
1090				memset(paddr + offset, 0xff,
1091				       PAGE_SIZE - offset);
1092				kunmap_atomic(paddr, KM_USER0);
1093				write_page(bitmap, page, 1);
1094
1095				ret = -EIO;
1096				if (bitmap->flags & BITMAP_WRITE_ERROR)
 
1097					goto err;
1098			}
1099		}
1100		paddr = kmap_atomic(page, KM_USER0);
1101		if (bitmap->flags & BITMAP_HOSTENDIAN)
1102			b = test_bit(bit, paddr);
1103		else
1104			b = test_bit_le(bit, paddr);
1105		kunmap_atomic(paddr, KM_USER0);
1106		if (b) {
1107			/* if the disk bit is set, set the memory bit */
1108			int needed = ((sector_t)(i+1) << (CHUNK_BLOCK_SHIFT(bitmap))
1109				      >= start);
1110			bitmap_set_memory_bits(bitmap,
1111					       (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap),
1112					       needed);
1113			bit_cnt++;
1114			set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1115		}
1116	}
1117
1118	/* everything went OK */
1119	ret = 0;
1120	bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
1121
1122	if (bit_cnt) { /* Kick recovery if any bits were set */
1123		set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1124		md_wakeup_thread(bitmap->mddev->thread);
1125	}
1126
1127	printk(KERN_INFO "%s: bitmap initialized from disk: "
1128	       "read %lu/%lu pages, set %lu of %lu bits\n",
1129	       bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, chunks);
 
1130
1131	return 0;
1132
1133 err:
1134	printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
1135	       bmname(bitmap), ret);
1136	return ret;
1137}
1138
1139void bitmap_write_all(struct bitmap *bitmap)
1140{
1141	/* We don't actually write all bitmap blocks here,
1142	 * just flag them as needing to be written
1143	 */
1144	int i;
1145
1146	for (i = 0; i < bitmap->file_pages; i++)
1147		set_page_attr(bitmap, bitmap->filemap[i],
 
 
 
 
 
 
1148			      BITMAP_PAGE_NEEDWRITE);
 
1149}
1150
1151static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
 
1152{
1153	sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1154	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1155	bitmap->bp[page].count += inc;
1156	bitmap_checkfree(bitmap, page);
1157}
1158static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
 
 
 
 
 
 
 
 
 
 
 
1159					    sector_t offset, sector_t *blocks,
1160					    int create);
1161
1162/*
1163 * bitmap daemon -- periodically wakes up to clean bits and flush pages
1164 *			out to disk
1165 */
1166
1167void bitmap_daemon_work(mddev_t *mddev)
1168{
1169	struct bitmap *bitmap;
1170	unsigned long j;
1171	unsigned long flags;
1172	struct page *page = NULL, *lastpage = NULL;
1173	sector_t blocks;
1174	void *paddr;
1175
1176	/* Use a mutex to guard daemon_work against
1177	 * bitmap_destroy.
1178	 */
1179	mutex_lock(&mddev->bitmap_info.mutex);
1180	bitmap = mddev->bitmap;
1181	if (bitmap == NULL) {
1182		mutex_unlock(&mddev->bitmap_info.mutex);
1183		return;
1184	}
1185	if (time_before(jiffies, bitmap->daemon_lastrun
1186			+ bitmap->mddev->bitmap_info.daemon_sleep))
1187		goto done;
1188
1189	bitmap->daemon_lastrun = jiffies;
1190	if (bitmap->allclean) {
1191		bitmap->mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1192		goto done;
1193	}
1194	bitmap->allclean = 1;
1195
1196	spin_lock_irqsave(&bitmap->lock, flags);
1197	for (j = 0; j < bitmap->chunks; j++) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1198		bitmap_counter_t *bmc;
1199		if (!bitmap->filemap)
1200			/* error or shutdown */
1201			break;
1202
1203		page = filemap_get_page(bitmap, j);
1204
1205		if (page != lastpage) {
1206			/* skip this page unless it's marked as needing cleaning */
1207			if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
1208				int need_write = test_page_attr(bitmap, page,
1209								BITMAP_PAGE_NEEDWRITE);
1210				if (need_write)
1211					clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1212
1213				spin_unlock_irqrestore(&bitmap->lock, flags);
1214				if (need_write) {
1215					write_page(bitmap, page, 0);
1216					bitmap->allclean = 0;
1217				}
1218				spin_lock_irqsave(&bitmap->lock, flags);
1219				j |= (PAGE_BITS - 1);
1220				continue;
1221			}
1222
1223			/* grab the new page, sync and release the old */
1224			if (lastpage != NULL) {
1225				if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1226					clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1227					spin_unlock_irqrestore(&bitmap->lock, flags);
1228					write_page(bitmap, lastpage, 0);
1229				} else {
1230					set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1231					spin_unlock_irqrestore(&bitmap->lock, flags);
1232				}
1233			} else
1234				spin_unlock_irqrestore(&bitmap->lock, flags);
1235			lastpage = page;
1236
1237			/* We are possibly going to clear some bits, so make
1238			 * sure that events_cleared is up-to-date.
1239			 */
1240			if (bitmap->need_sync &&
1241			    bitmap->mddev->bitmap_info.external == 0) {
1242				bitmap_super_t *sb;
1243				bitmap->need_sync = 0;
1244				sb = kmap_atomic(bitmap->sb_page, KM_USER0);
1245				sb->events_cleared =
1246					cpu_to_le64(bitmap->events_cleared);
1247				kunmap_atomic(sb, KM_USER0);
1248				write_page(bitmap, bitmap->sb_page, 1);
1249			}
1250			spin_lock_irqsave(&bitmap->lock, flags);
1251			if (!bitmap->need_sync)
1252				clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1253		}
1254		bmc = bitmap_get_counter(bitmap,
1255					 (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
1256					 &blocks, 0);
1257		if (bmc) {
1258			if (*bmc)
1259				bitmap->allclean = 0;
1260
1261			if (*bmc == 2) {
1262				*bmc = 1; /* maybe clear the bit next time */
1263				set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1264			} else if (*bmc == 1 && !bitmap->need_sync) {
1265				/* we can clear the bit */
1266				*bmc = 0;
1267				bitmap_count_page(bitmap,
1268						  (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
1269						  -1);
1270
1271				/* clear the bit */
1272				paddr = kmap_atomic(page, KM_USER0);
1273				if (bitmap->flags & BITMAP_HOSTENDIAN)
1274					clear_bit(file_page_offset(bitmap, j),
1275						  paddr);
1276				else
1277					__clear_bit_le(
1278							file_page_offset(bitmap,
1279									 j),
1280							paddr);
1281				kunmap_atomic(paddr, KM_USER0);
1282			}
1283		} else
1284			j |= PAGE_COUNTER_MASK;
1285	}
1286	spin_unlock_irqrestore(&bitmap->lock, flags);
1287
1288	/* now sync the final page */
1289	if (lastpage != NULL) {
1290		spin_lock_irqsave(&bitmap->lock, flags);
1291		if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1292			clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1293			spin_unlock_irqrestore(&bitmap->lock, flags);
1294			write_page(bitmap, lastpage, 0);
1295		} else {
1296			set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
1297			spin_unlock_irqrestore(&bitmap->lock, flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1298		}
1299	}
1300
1301 done:
1302	if (bitmap->allclean == 0)
1303		bitmap->mddev->thread->timeout =
1304			bitmap->mddev->bitmap_info.daemon_sleep;
1305	mutex_unlock(&mddev->bitmap_info.mutex);
1306}
1307
1308static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
1309					    sector_t offset, sector_t *blocks,
1310					    int create)
1311__releases(bitmap->lock)
1312__acquires(bitmap->lock)
1313{
1314	/* If 'create', we might release the lock and reclaim it.
1315	 * The lock must have been taken with interrupts enabled.
1316	 * If !create, we don't release the lock.
1317	 */
1318	sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
1319	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
1320	unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
1321	sector_t csize;
1322	int err;
1323
1324	err = bitmap_checkpage(bitmap, page, create);
1325
1326	if (bitmap->bp[page].hijacked ||
1327	    bitmap->bp[page].map == NULL)
1328		csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) +
1329					  PAGE_COUNTER_SHIFT - 1);
1330	else
1331		csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
1332	*blocks = csize - (offset & (csize - 1));
1333
1334	if (err < 0)
1335		return NULL;
1336
1337	/* now locked ... */
1338
1339	if (bitmap->bp[page].hijacked) { /* hijacked pointer */
1340		/* should we use the first or second counter field
1341		 * of the hijacked pointer? */
1342		int hi = (pageoff > PAGE_COUNTER_MASK);
1343		return  &((bitmap_counter_t *)
1344			  &bitmap->bp[page].map)[hi];
1345	} else /* page is allocated */
1346		return (bitmap_counter_t *)
1347			&(bitmap->bp[page].map[pageoff]);
1348}
1349
1350int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1351{
1352	if (!bitmap)
1353		return 0;
1354
1355	if (behind) {
1356		int bw;
1357		atomic_inc(&bitmap->behind_writes);
1358		bw = atomic_read(&bitmap->behind_writes);
1359		if (bw > bitmap->behind_writes_used)
1360			bitmap->behind_writes_used = bw;
1361
1362		PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n",
1363		       bw, bitmap->max_write_behind);
1364	}
1365
1366	while (sectors) {
1367		sector_t blocks;
1368		bitmap_counter_t *bmc;
1369
1370		spin_lock_irq(&bitmap->lock);
1371		bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
1372		if (!bmc) {
1373			spin_unlock_irq(&bitmap->lock);
1374			return 0;
1375		}
1376
1377		if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1378			DEFINE_WAIT(__wait);
1379			/* note that it is safe to do the prepare_to_wait
1380			 * after the test as long as we do it before dropping
1381			 * the spinlock.
1382			 */
1383			prepare_to_wait(&bitmap->overflow_wait, &__wait,
1384					TASK_UNINTERRUPTIBLE);
1385			spin_unlock_irq(&bitmap->lock);
1386			io_schedule();
1387			finish_wait(&bitmap->overflow_wait, &__wait);
1388			continue;
1389		}
1390
1391		switch (*bmc) {
1392		case 0:
1393			bitmap_file_set_bit(bitmap, offset);
1394			bitmap_count_page(bitmap, offset, 1);
1395			/* fall through */
1396		case 1:
1397			*bmc = 2;
1398		}
1399
1400		(*bmc)++;
1401
1402		spin_unlock_irq(&bitmap->lock);
1403
1404		offset += blocks;
1405		if (sectors > blocks)
1406			sectors -= blocks;
1407		else
1408			sectors = 0;
1409	}
1410	bitmap->allclean = 0;
1411	return 0;
1412}
1413EXPORT_SYMBOL(bitmap_startwrite);
1414
1415void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1416		     int success, int behind)
1417{
1418	if (!bitmap)
1419		return;
1420	if (behind) {
1421		if (atomic_dec_and_test(&bitmap->behind_writes))
1422			wake_up(&bitmap->behind_wait);
1423		PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n",
1424		  atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
 
1425	}
1426	if (bitmap->mddev->degraded)
1427		/* Never clear bits or update events_cleared when degraded */
1428		success = 0;
1429
1430	while (sectors) {
1431		sector_t blocks;
1432		unsigned long flags;
1433		bitmap_counter_t *bmc;
1434
1435		spin_lock_irqsave(&bitmap->lock, flags);
1436		bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
1437		if (!bmc) {
1438			spin_unlock_irqrestore(&bitmap->lock, flags);
1439			return;
1440		}
1441
1442		if (success &&
1443		    bitmap->events_cleared < bitmap->mddev->events) {
1444			bitmap->events_cleared = bitmap->mddev->events;
1445			bitmap->need_sync = 1;
1446			sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1447		}
1448
1449		if (!success && !NEEDED(*bmc))
1450			*bmc |= NEEDED_MASK;
1451
1452		if (COUNTER(*bmc) == COUNTER_MAX)
1453			wake_up(&bitmap->overflow_wait);
1454
1455		(*bmc)--;
1456		if (*bmc <= 2)
1457			set_page_attr(bitmap,
1458				      filemap_get_page(
1459					      bitmap,
1460					      offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1461				      BITMAP_PAGE_CLEAN);
1462
1463		spin_unlock_irqrestore(&bitmap->lock, flags);
1464		offset += blocks;
1465		if (sectors > blocks)
1466			sectors -= blocks;
1467		else
1468			sectors = 0;
1469	}
1470}
1471EXPORT_SYMBOL(bitmap_endwrite);
1472
1473static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1474			       int degraded)
1475{
1476	bitmap_counter_t *bmc;
1477	int rv;
1478	if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
1479		*blocks = 1024;
1480		return 1; /* always resync if no bitmap */
1481	}
1482	spin_lock_irq(&bitmap->lock);
1483	bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1484	rv = 0;
1485	if (bmc) {
1486		/* locked */
1487		if (RESYNC(*bmc))
1488			rv = 1;
1489		else if (NEEDED(*bmc)) {
1490			rv = 1;
1491			if (!degraded) { /* don't set/clear bits if degraded */
1492				*bmc |= RESYNC_MASK;
1493				*bmc &= ~NEEDED_MASK;
1494			}
1495		}
1496	}
1497	spin_unlock_irq(&bitmap->lock);
1498	bitmap->allclean = 0;
1499	return rv;
1500}
1501
1502int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1503		      int degraded)
1504{
1505	/* bitmap_start_sync must always report on multiples of whole
1506	 * pages, otherwise resync (which is very PAGE_SIZE based) will
1507	 * get confused.
1508	 * So call __bitmap_start_sync repeatedly (if needed) until
1509	 * At least PAGE_SIZE>>9 blocks are covered.
1510	 * Return the 'or' of the result.
1511	 */
1512	int rv = 0;
1513	sector_t blocks1;
1514
1515	*blocks = 0;
1516	while (*blocks < (PAGE_SIZE>>9)) {
1517		rv |= __bitmap_start_sync(bitmap, offset,
1518					  &blocks1, degraded);
1519		offset += blocks1;
1520		*blocks += blocks1;
1521	}
1522	return rv;
1523}
1524EXPORT_SYMBOL(bitmap_start_sync);
1525
1526void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1527{
1528	bitmap_counter_t *bmc;
1529	unsigned long flags;
1530
1531	if (bitmap == NULL) {
1532		*blocks = 1024;
1533		return;
1534	}
1535	spin_lock_irqsave(&bitmap->lock, flags);
1536	bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
1537	if (bmc == NULL)
1538		goto unlock;
1539	/* locked */
1540	if (RESYNC(*bmc)) {
1541		*bmc &= ~RESYNC_MASK;
1542
1543		if (!NEEDED(*bmc) && aborted)
1544			*bmc |= NEEDED_MASK;
1545		else {
1546			if (*bmc <= 2)
1547				set_page_attr(bitmap,
1548					      filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
1549					      BITMAP_PAGE_CLEAN);
1550		}
1551	}
1552 unlock:
1553	spin_unlock_irqrestore(&bitmap->lock, flags);
1554	bitmap->allclean = 0;
1555}
1556EXPORT_SYMBOL(bitmap_end_sync);
1557
1558void bitmap_close_sync(struct bitmap *bitmap)
1559{
1560	/* Sync has finished, and any bitmap chunks that weren't synced
1561	 * properly have been aborted.  It remains to us to clear the
1562	 * RESYNC bit wherever it is still on
1563	 */
1564	sector_t sector = 0;
1565	sector_t blocks;
1566	if (!bitmap)
1567		return;
1568	while (sector < bitmap->mddev->resync_max_sectors) {
1569		bitmap_end_sync(bitmap, sector, &blocks, 0);
1570		sector += blocks;
1571	}
1572}
1573EXPORT_SYMBOL(bitmap_close_sync);
1574
1575void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
1576{
1577	sector_t s = 0;
1578	sector_t blocks;
1579
1580	if (!bitmap)
1581		return;
1582	if (sector == 0) {
1583		bitmap->last_end_sync = jiffies;
1584		return;
1585	}
1586	if (time_before(jiffies, (bitmap->last_end_sync
1587				  + bitmap->mddev->bitmap_info.daemon_sleep)))
1588		return;
1589	wait_event(bitmap->mddev->recovery_wait,
1590		   atomic_read(&bitmap->mddev->recovery_active) == 0);
1591
1592	bitmap->mddev->curr_resync_completed = sector;
1593	set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1594	sector &= ~((1ULL << CHUNK_BLOCK_SHIFT(bitmap)) - 1);
1595	s = 0;
1596	while (s < sector && s < bitmap->mddev->resync_max_sectors) {
1597		bitmap_end_sync(bitmap, s, &blocks, 0);
1598		s += blocks;
1599	}
1600	bitmap->last_end_sync = jiffies;
1601	sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1602}
1603EXPORT_SYMBOL(bitmap_cond_end_sync);
1604
1605static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1606{
1607	/* For each chunk covered by any of these sectors, set the
1608	 * counter to 1 and set resync_needed.  They should all
1609	 * be 0 at this point
1610	 */
1611
1612	sector_t secs;
1613	bitmap_counter_t *bmc;
1614	spin_lock_irq(&bitmap->lock);
1615	bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
1616	if (!bmc) {
1617		spin_unlock_irq(&bitmap->lock);
1618		return;
1619	}
1620	if (!*bmc) {
1621		struct page *page;
1622		*bmc = 1 | (needed ? NEEDED_MASK : 0);
1623		bitmap_count_page(bitmap, offset, 1);
1624		page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
1625		set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1626	}
1627	spin_unlock_irq(&bitmap->lock);
1628	bitmap->allclean = 0;
1629}
1630
1631/* dirty the memory and file bits for bitmap chunks "s" to "e" */
1632void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
1633{
1634	unsigned long chunk;
1635
1636	for (chunk = s; chunk <= e; chunk++) {
1637		sector_t sec = (sector_t)chunk << CHUNK_BLOCK_SHIFT(bitmap);
1638		bitmap_set_memory_bits(bitmap, sec, 1);
1639		bitmap_file_set_bit(bitmap, sec);
1640		if (sec < bitmap->mddev->recovery_cp)
1641			/* We are asserting that the array is dirty,
1642			 * so move the recovery_cp address back so
1643			 * that it is obvious that it is dirty
1644			 */
1645			bitmap->mddev->recovery_cp = sec;
1646	}
1647}
1648
1649/*
1650 * flush out any pending updates
1651 */
1652void bitmap_flush(mddev_t *mddev)
1653{
1654	struct bitmap *bitmap = mddev->bitmap;
1655	long sleep;
1656
1657	if (!bitmap) /* there was no bitmap */
1658		return;
1659
1660	/* run the daemon_work three time to ensure everything is flushed
1661	 * that can be
1662	 */
1663	sleep = mddev->bitmap_info.daemon_sleep * 2;
1664	bitmap->daemon_lastrun -= sleep;
1665	bitmap_daemon_work(mddev);
1666	bitmap->daemon_lastrun -= sleep;
1667	bitmap_daemon_work(mddev);
1668	bitmap->daemon_lastrun -= sleep;
1669	bitmap_daemon_work(mddev);
1670	bitmap_update_sb(bitmap);
1671}
1672
1673/*
1674 * free memory that was allocated
1675 */
1676static void bitmap_free(struct bitmap *bitmap)
1677{
1678	unsigned long k, pages;
1679	struct bitmap_page *bp;
1680
1681	if (!bitmap) /* there was no bitmap */
1682		return;
1683
1684	/* release the bitmap file and kill the daemon */
1685	bitmap_file_put(bitmap);
 
 
 
 
1686
1687	bp = bitmap->bp;
1688	pages = bitmap->pages;
1689
1690	/* free all allocated memory */
1691
1692	if (bp) /* deallocate the page memory */
1693		for (k = 0; k < pages; k++)
1694			if (bp[k].map && !bp[k].hijacked)
1695				kfree(bp[k].map);
1696	kfree(bp);
1697	kfree(bitmap);
1698}
1699
1700void bitmap_destroy(mddev_t *mddev)
1701{
1702	struct bitmap *bitmap = mddev->bitmap;
1703
1704	if (!bitmap) /* there was no bitmap */
1705		return;
1706
1707	mutex_lock(&mddev->bitmap_info.mutex);
1708	mddev->bitmap = NULL; /* disconnect from the md device */
1709	mutex_unlock(&mddev->bitmap_info.mutex);
1710	if (mddev->thread)
1711		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1712
1713	if (bitmap->sysfs_can_clear)
1714		sysfs_put(bitmap->sysfs_can_clear);
1715
1716	bitmap_free(bitmap);
1717}
1718
1719/*
1720 * initialize the bitmap structure
1721 * if this returns an error, bitmap_destroy must be called to do clean up
1722 */
1723int bitmap_create(mddev_t *mddev)
1724{
1725	struct bitmap *bitmap;
1726	sector_t blocks = mddev->resync_max_sectors;
1727	unsigned long chunks;
1728	unsigned long pages;
1729	struct file *file = mddev->bitmap_info.file;
1730	int err;
1731	struct sysfs_dirent *bm = NULL;
1732
1733	BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1734
1735	if (!file
1736	    && !mddev->bitmap_info.offset) /* bitmap disabled, nothing to do */
1737		return 0;
1738
1739	BUG_ON(file && mddev->bitmap_info.offset);
1740
1741	bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1742	if (!bitmap)
1743		return -ENOMEM;
1744
1745	spin_lock_init(&bitmap->lock);
1746	atomic_set(&bitmap->pending_writes, 0);
1747	init_waitqueue_head(&bitmap->write_wait);
1748	init_waitqueue_head(&bitmap->overflow_wait);
1749	init_waitqueue_head(&bitmap->behind_wait);
1750
1751	bitmap->mddev = mddev;
1752
1753	if (mddev->kobj.sd)
1754		bm = sysfs_get_dirent(mddev->kobj.sd, NULL, "bitmap");
1755	if (bm) {
1756		bitmap->sysfs_can_clear = sysfs_get_dirent(bm, NULL, "can_clear");
1757		sysfs_put(bm);
1758	} else
1759		bitmap->sysfs_can_clear = NULL;
1760
1761	bitmap->file = file;
1762	if (file) {
1763		get_file(file);
1764		/* As future accesses to this file will use bmap,
1765		 * and bypass the page cache, we must sync the file
1766		 * first.
1767		 */
1768		vfs_fsync(file, 1);
1769	}
1770	/* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1771	if (!mddev->bitmap_info.external) {
1772		/*
1773		 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
1774		 * instructing us to create a new on-disk bitmap instance.
1775		 */
1776		if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
1777			err = bitmap_new_disk_sb(bitmap);
1778		else
1779			err = bitmap_read_sb(bitmap);
1780	} else {
1781		err = 0;
1782		if (mddev->bitmap_info.chunksize == 0 ||
1783		    mddev->bitmap_info.daemon_sleep == 0)
1784			/* chunksize and time_base need to be
1785			 * set first. */
1786			err = -EINVAL;
1787	}
1788	if (err)
1789		goto error;
1790
1791	bitmap->daemon_lastrun = jiffies;
1792	bitmap->chunkshift = ffz(~mddev->bitmap_info.chunksize);
1793
1794	/* now that chunksize and chunkshift are set, we can use these macros */
1795	chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) >>
1796			CHUNK_BLOCK_SHIFT(bitmap);
1797	pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1798
1799	BUG_ON(!pages);
1800
1801	bitmap->chunks = chunks;
1802	bitmap->pages = pages;
1803	bitmap->missing_pages = pages;
1804
1805#ifdef INJECT_FATAL_FAULT_1
1806	bitmap->bp = NULL;
1807#else
1808	bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1809#endif
1810	err = -ENOMEM;
1811	if (!bitmap->bp)
1812		goto error;
1813
1814	printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
1815		pages, bmname(bitmap));
1816
1817	mddev->bitmap = bitmap;
1818
1819
1820	return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
1821
1822 error:
1823	bitmap_free(bitmap);
1824	return err;
1825}
1826
1827int bitmap_load(mddev_t *mddev)
1828{
1829	int err = 0;
1830	sector_t start = 0;
1831	sector_t sector = 0;
1832	struct bitmap *bitmap = mddev->bitmap;
1833
1834	if (!bitmap)
1835		goto out;
1836
1837	/* Clear out old bitmap info first:  Either there is none, or we
1838	 * are resuming after someone else has possibly changed things,
1839	 * so we should forget old cached info.
1840	 * All chunks should be clean, but some might need_sync.
1841	 */
1842	while (sector < mddev->resync_max_sectors) {
1843		sector_t blocks;
1844		bitmap_start_sync(bitmap, sector, &blocks, 0);
1845		sector += blocks;
1846	}
1847	bitmap_close_sync(bitmap);
1848
1849	if (mddev->degraded == 0
1850	    || bitmap->events_cleared == mddev->events)
1851		/* no need to keep dirty bits to optimise a
1852		 * re-add of a missing device */
1853		start = mddev->recovery_cp;
1854
 
1855	err = bitmap_init_from_disk(bitmap, start);
 
1856
1857	if (err)
1858		goto out;
 
 
 
 
1859
1860	mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1861	md_wakeup_thread(mddev->thread);
1862
1863	bitmap_update_sb(bitmap);
1864
1865	if (bitmap->flags & BITMAP_WRITE_ERROR)
1866		err = -EIO;
1867out:
1868	return err;
1869}
1870EXPORT_SYMBOL_GPL(bitmap_load);
1871
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1872static ssize_t
1873location_show(mddev_t *mddev, char *page)
1874{
1875	ssize_t len;
1876	if (mddev->bitmap_info.file)
1877		len = sprintf(page, "file");
1878	else if (mddev->bitmap_info.offset)
1879		len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
1880	else
1881		len = sprintf(page, "none");
1882	len += sprintf(page+len, "\n");
1883	return len;
1884}
1885
1886static ssize_t
1887location_store(mddev_t *mddev, const char *buf, size_t len)
1888{
1889
1890	if (mddev->pers) {
1891		if (!mddev->pers->quiesce)
1892			return -EBUSY;
1893		if (mddev->recovery || mddev->sync_thread)
1894			return -EBUSY;
1895	}
1896
1897	if (mddev->bitmap || mddev->bitmap_info.file ||
1898	    mddev->bitmap_info.offset) {
1899		/* bitmap already configured.  Only option is to clear it */
1900		if (strncmp(buf, "none", 4) != 0)
1901			return -EBUSY;
1902		if (mddev->pers) {
1903			mddev->pers->quiesce(mddev, 1);
1904			bitmap_destroy(mddev);
1905			mddev->pers->quiesce(mddev, 0);
1906		}
1907		mddev->bitmap_info.offset = 0;
1908		if (mddev->bitmap_info.file) {
1909			struct file *f = mddev->bitmap_info.file;
1910			mddev->bitmap_info.file = NULL;
1911			restore_bitmap_write_access(f);
1912			fput(f);
1913		}
1914	} else {
1915		/* No bitmap, OK to set a location */
1916		long long offset;
1917		if (strncmp(buf, "none", 4) == 0)
1918			/* nothing to be done */;
1919		else if (strncmp(buf, "file:", 5) == 0) {
1920			/* Not supported yet */
1921			return -EINVAL;
1922		} else {
1923			int rv;
1924			if (buf[0] == '+')
1925				rv = strict_strtoll(buf+1, 10, &offset);
1926			else
1927				rv = strict_strtoll(buf, 10, &offset);
1928			if (rv)
1929				return rv;
1930			if (offset == 0)
1931				return -EINVAL;
1932			if (mddev->bitmap_info.external == 0 &&
1933			    mddev->major_version == 0 &&
1934			    offset != mddev->bitmap_info.default_offset)
1935				return -EINVAL;
1936			mddev->bitmap_info.offset = offset;
1937			if (mddev->pers) {
1938				mddev->pers->quiesce(mddev, 1);
1939				rv = bitmap_create(mddev);
 
 
1940				if (rv) {
1941					bitmap_destroy(mddev);
1942					mddev->bitmap_info.offset = 0;
1943				}
1944				mddev->pers->quiesce(mddev, 0);
1945				if (rv)
1946					return rv;
1947			}
1948		}
1949	}
1950	if (!mddev->external) {
1951		/* Ensure new bitmap info is stored in
1952		 * metadata promptly.
1953		 */
1954		set_bit(MD_CHANGE_DEVS, &mddev->flags);
1955		md_wakeup_thread(mddev->thread);
1956	}
1957	return len;
1958}
1959
1960static struct md_sysfs_entry bitmap_location =
1961__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
1962
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1963static ssize_t
1964timeout_show(mddev_t *mddev, char *page)
1965{
1966	ssize_t len;
1967	unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
1968	unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
1969
1970	len = sprintf(page, "%lu", secs);
1971	if (jifs)
1972		len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
1973	len += sprintf(page+len, "\n");
1974	return len;
1975}
1976
1977static ssize_t
1978timeout_store(mddev_t *mddev, const char *buf, size_t len)
1979{
1980	/* timeout can be set at any time */
1981	unsigned long timeout;
1982	int rv = strict_strtoul_scaled(buf, &timeout, 4);
1983	if (rv)
1984		return rv;
1985
1986	/* just to make sure we don't overflow... */
1987	if (timeout >= LONG_MAX / HZ)
1988		return -EINVAL;
1989
1990	timeout = timeout * HZ / 10000;
1991
1992	if (timeout >= MAX_SCHEDULE_TIMEOUT)
1993		timeout = MAX_SCHEDULE_TIMEOUT-1;
1994	if (timeout < 1)
1995		timeout = 1;
1996	mddev->bitmap_info.daemon_sleep = timeout;
1997	if (mddev->thread) {
1998		/* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
1999		 * the bitmap is all clean and we don't need to
2000		 * adjust the timeout right now
2001		 */
2002		if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
2003			mddev->thread->timeout = timeout;
2004			md_wakeup_thread(mddev->thread);
2005		}
2006	}
2007	return len;
2008}
2009
2010static struct md_sysfs_entry bitmap_timeout =
2011__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
2012
2013static ssize_t
2014backlog_show(mddev_t *mddev, char *page)
2015{
2016	return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
2017}
2018
2019static ssize_t
2020backlog_store(mddev_t *mddev, const char *buf, size_t len)
2021{
2022	unsigned long backlog;
2023	int rv = strict_strtoul(buf, 10, &backlog);
2024	if (rv)
2025		return rv;
2026	if (backlog > COUNTER_MAX)
2027		return -EINVAL;
2028	mddev->bitmap_info.max_write_behind = backlog;
2029	return len;
2030}
2031
2032static struct md_sysfs_entry bitmap_backlog =
2033__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
2034
2035static ssize_t
2036chunksize_show(mddev_t *mddev, char *page)
2037{
2038	return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
2039}
2040
2041static ssize_t
2042chunksize_store(mddev_t *mddev, const char *buf, size_t len)
2043{
2044	/* Can only be changed when no bitmap is active */
2045	int rv;
2046	unsigned long csize;
2047	if (mddev->bitmap)
2048		return -EBUSY;
2049	rv = strict_strtoul(buf, 10, &csize);
2050	if (rv)
2051		return rv;
2052	if (csize < 512 ||
2053	    !is_power_of_2(csize))
2054		return -EINVAL;
2055	mddev->bitmap_info.chunksize = csize;
2056	return len;
2057}
2058
2059static struct md_sysfs_entry bitmap_chunksize =
2060__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
2061
2062static ssize_t metadata_show(mddev_t *mddev, char *page)
2063{
2064	return sprintf(page, "%s\n", (mddev->bitmap_info.external
2065				      ? "external" : "internal"));
2066}
2067
2068static ssize_t metadata_store(mddev_t *mddev, const char *buf, size_t len)
2069{
2070	if (mddev->bitmap ||
2071	    mddev->bitmap_info.file ||
2072	    mddev->bitmap_info.offset)
2073		return -EBUSY;
2074	if (strncmp(buf, "external", 8) == 0)
2075		mddev->bitmap_info.external = 1;
2076	else if (strncmp(buf, "internal", 8) == 0)
2077		mddev->bitmap_info.external = 0;
2078	else
2079		return -EINVAL;
2080	return len;
2081}
2082
2083static struct md_sysfs_entry bitmap_metadata =
2084__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
2085
2086static ssize_t can_clear_show(mddev_t *mddev, char *page)
2087{
2088	int len;
2089	if (mddev->bitmap)
2090		len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
2091					     "false" : "true"));
2092	else
2093		len = sprintf(page, "\n");
2094	return len;
2095}
2096
2097static ssize_t can_clear_store(mddev_t *mddev, const char *buf, size_t len)
2098{
2099	if (mddev->bitmap == NULL)
2100		return -ENOENT;
2101	if (strncmp(buf, "false", 5) == 0)
2102		mddev->bitmap->need_sync = 1;
2103	else if (strncmp(buf, "true", 4) == 0) {
2104		if (mddev->degraded)
2105			return -EBUSY;
2106		mddev->bitmap->need_sync = 0;
2107	} else
2108		return -EINVAL;
2109	return len;
2110}
2111
2112static struct md_sysfs_entry bitmap_can_clear =
2113__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
2114
2115static ssize_t
2116behind_writes_used_show(mddev_t *mddev, char *page)
2117{
2118	if (mddev->bitmap == NULL)
2119		return sprintf(page, "0\n");
2120	return sprintf(page, "%lu\n",
2121		       mddev->bitmap->behind_writes_used);
2122}
2123
2124static ssize_t
2125behind_writes_used_reset(mddev_t *mddev, const char *buf, size_t len)
2126{
2127	if (mddev->bitmap)
2128		mddev->bitmap->behind_writes_used = 0;
2129	return len;
2130}
2131
2132static struct md_sysfs_entry max_backlog_used =
2133__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
2134       behind_writes_used_show, behind_writes_used_reset);
2135
2136static struct attribute *md_bitmap_attrs[] = {
2137	&bitmap_location.attr,
 
2138	&bitmap_timeout.attr,
2139	&bitmap_backlog.attr,
2140	&bitmap_chunksize.attr,
2141	&bitmap_metadata.attr,
2142	&bitmap_can_clear.attr,
2143	&max_backlog_used.attr,
2144	NULL
2145};
2146struct attribute_group md_bitmap_group = {
2147	.name = "bitmap",
2148	.attrs = md_bitmap_attrs,
2149};
2150