bitmap.c 44.8 KB
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/*
 * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
 *
 * bitmap_create  - sets up the bitmap structure
 * bitmap_destroy - destroys the bitmap structure
 *
 * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
 * - added disk storage for bitmap
 * - changes to allow various bitmap chunk sizes
 */

/*
 * Still to do:
 *
 * flush after percent set rather than just time based. (maybe both).
 * wait if count gets too high, wake when it drops to half.
 */

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#include <linux/blkdev.h>
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#include <linux/module.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/buffer_head.h>
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#include "md.h"
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#include "bitmap.h"
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/* debug macros */

#define DEBUG 0

#if DEBUG
/* these are for debugging purposes only! */

/* define one and only one of these */
#define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */
#define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/
#define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */
#define INJECT_FAULTS_4 0 /* undef */
#define INJECT_FAULTS_5 0 /* undef */
#define INJECT_FAULTS_6 0

/* if these are defined, the driver will fail! debug only */
#define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */
#define INJECT_FATAL_FAULT_2 0 /* undef */
#define INJECT_FATAL_FAULT_3 0 /* undef */
#endif

//#define DPRINTK PRINTK /* set this NULL to avoid verbose debug output */
#define DPRINTK(x...) do { } while(0)

#ifndef PRINTK
#  if DEBUG > 0
#    define PRINTK(x...) printk(KERN_DEBUG x)
#  else
#    define PRINTK(x...)
#  endif
#endif

static inline char * bmname(struct bitmap *bitmap)
{
	return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
}


/*
 * just a placeholder - calls kmalloc for bitmap pages
 */
static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
{
	unsigned char *page;

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#ifdef INJECT_FAULTS_1
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	page = NULL;
#else
	page = kmalloc(PAGE_SIZE, GFP_NOIO);
#endif
	if (!page)
		printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
	else
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		PRINTK("%s: bitmap_alloc_page: allocated page at %p\n",
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			bmname(bitmap), page);
	return page;
}

/*
 * for now just a placeholder -- just calls kfree for bitmap pages
 */
static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page)
{
	PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page);
	kfree(page);
}

/*
 * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
 *
 * 1) check to see if this page is allocated, if it's not then try to alloc
 * 2) if the alloc fails, set the page's hijacked flag so we'll use the
 *    page pointer directly as a counter
 *
 * if we find our page, we increment the page's refcount so that it stays
 * allocated while we're using it
 */
static int bitmap_checkpage(struct bitmap *bitmap, unsigned long page, int create)
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__releases(bitmap->lock)
__acquires(bitmap->lock)
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{
	unsigned char *mappage;

	if (page >= bitmap->pages) {
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		/* This can happen if bitmap_start_sync goes beyond
		 * End-of-device while looking for a whole page.
		 * It is harmless.
		 */
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		return -EINVAL;
	}


	if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
		return 0;

	if (bitmap->bp[page].map) /* page is already allocated, just return */
		return 0;

	if (!create)
		return -ENOENT;

	spin_unlock_irq(&bitmap->lock);

	/* this page has not been allocated yet */

	if ((mappage = bitmap_alloc_page(bitmap)) == NULL) {
		PRINTK("%s: bitmap map page allocation failed, hijacking\n",
			bmname(bitmap));
		/* failed - set the hijacked flag so that we can use the
		 * pointer as a counter */
		spin_lock_irq(&bitmap->lock);
		if (!bitmap->bp[page].map)
			bitmap->bp[page].hijacked = 1;
		goto out;
	}

	/* got a page */

	spin_lock_irq(&bitmap->lock);

	/* recheck the page */

	if (bitmap->bp[page].map || bitmap->bp[page].hijacked) {
		/* somebody beat us to getting the page */
		bitmap_free_page(bitmap, mappage);
		return 0;
	}

	/* no page was in place and we have one, so install it */

	memset(mappage, 0, PAGE_SIZE);
	bitmap->bp[page].map = mappage;
	bitmap->missing_pages--;
out:
	return 0;
}


/* if page is completely empty, put it back on the free list, or dealloc it */
/* if page was hijacked, unmark the flag so it might get alloced next time */
/* Note: lock should be held when calling this */
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static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
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{
	char *ptr;

	if (bitmap->bp[page].count) /* page is still busy */
		return;

	/* page is no longer in use, it can be released */

	if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
		bitmap->bp[page].hijacked = 0;
		bitmap->bp[page].map = NULL;
		return;
	}

	/* normal case, free the page */

#if 0
/* actually ... let's not.  We will probably need the page again exactly when
 * memory is tight and we are flusing to disk
 */
	return;
#else
	ptr = bitmap->bp[page].map;
	bitmap->bp[page].map = NULL;
	bitmap->missing_pages++;
	bitmap_free_page(bitmap, ptr);
	return;
#endif
}


/*
 * bitmap file handling - read and write the bitmap file and its superblock
 */

/*
 * basic page I/O operations
 */

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/* IO operations when bitmap is stored near all superblocks */
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static struct page *read_sb_page(mddev_t *mddev, long offset,
				 struct page *page,
				 unsigned long index, int size)
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{
	/* choose a good rdev and read the page from there */

	mdk_rdev_t *rdev;
	sector_t target;

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	if (!page)
		page = alloc_page(GFP_KERNEL);
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	if (!page)
		return ERR_PTR(-ENOMEM);

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	list_for_each_entry(rdev, &mddev->disks, same_set) {
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		if (! test_bit(In_sync, &rdev->flags)
		    || test_bit(Faulty, &rdev->flags))
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			continue;

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		target = rdev->sb_start + offset + index * (PAGE_SIZE/512);
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		if (sync_page_io(rdev->bdev, target,
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				 roundup(size, bdev_logical_block_size(rdev->bdev)),
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				 page, READ)) {
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			page->index = index;
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			attach_page_buffers(page, NULL); /* so that free_buffer will
							  * quietly no-op */
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			return page;
		}
	}
	return ERR_PTR(-EIO);
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}

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static mdk_rdev_t *next_active_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
{
	/* Iterate the disks of an mddev, using rcu to protect access to the
	 * linked list, and raising the refcount of devices we return to ensure
	 * they don't disappear while in use.
	 * As devices are only added or removed when raid_disk is < 0 and
	 * nr_pending is 0 and In_sync is clear, the entries we return will
	 * still be in the same position on the list when we re-enter
	 * list_for_each_continue_rcu.
	 */
	struct list_head *pos;
	rcu_read_lock();
	if (rdev == NULL)
		/* start at the beginning */
		pos = &mddev->disks;
	else {
		/* release the previous rdev and start from there. */
		rdev_dec_pending(rdev, mddev);
		pos = &rdev->same_set;
	}
	list_for_each_continue_rcu(pos, &mddev->disks) {
		rdev = list_entry(pos, mdk_rdev_t, same_set);
		if (rdev->raid_disk >= 0 &&
		    !test_bit(Faulty, &rdev->flags)) {
			/* this is a usable devices */
			atomic_inc(&rdev->nr_pending);
			rcu_read_unlock();
			return rdev;
		}
	}
	rcu_read_unlock();
	return NULL;
}

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static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
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{
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	mdk_rdev_t *rdev = NULL;
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	mddev_t *mddev = bitmap->mddev;
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	while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
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			int size = PAGE_SIZE;
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			long offset = mddev->bitmap_info.offset;
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			if (page->index == bitmap->file_pages-1)
				size = roundup(bitmap->last_page_size,
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					       bdev_logical_block_size(rdev->bdev));
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			/* Just make sure we aren't corrupting data or
			 * metadata
			 */
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			if (offset < 0) {
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				/* DATA  BITMAP METADATA  */
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				if (offset
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				    + (long)(page->index * (PAGE_SIZE/512))
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				    + size/512 > 0)
					/* bitmap runs in to metadata */
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					goto bad_alignment;
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Andre Noll 已提交
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				if (rdev->data_offset + mddev->dev_sectors
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				    > rdev->sb_start + offset)
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					/* data runs in to bitmap */
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					goto bad_alignment;
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			} else if (rdev->sb_start < rdev->data_offset) {
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				/* METADATA BITMAP DATA */
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				if (rdev->sb_start
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				    + offset
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				    + page->index*(PAGE_SIZE/512) + size/512
				    > rdev->data_offset)
					/* bitmap runs in to data */
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					goto bad_alignment;
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			} else {
				/* DATA METADATA BITMAP - no problems */
			}
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			md_super_write(mddev, rdev,
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				       rdev->sb_start + offset
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				       + page->index * (PAGE_SIZE/512),
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				       size,
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				       page);
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	}
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	if (wait)
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		md_super_wait(mddev);
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	return 0;
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 bad_alignment:
	return -EINVAL;
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}

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static void bitmap_file_kick(struct bitmap *bitmap);
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/*
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 * write out a page to a file
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 */
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static void write_page(struct bitmap *bitmap, struct page *page, int wait)
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{
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	struct buffer_head *bh;
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	if (bitmap->file == NULL) {
		switch (write_sb_page(bitmap, page, wait)) {
		case -EINVAL:
			bitmap->flags |= BITMAP_WRITE_ERROR;
		}
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	} else {
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		bh = page_buffers(page);
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		while (bh && bh->b_blocknr) {
			atomic_inc(&bitmap->pending_writes);
			set_buffer_locked(bh);
			set_buffer_mapped(bh);
			submit_bh(WRITE, bh);
			bh = bh->b_this_page;
		}
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		if (wait) {
			wait_event(bitmap->write_wait,
				   atomic_read(&bitmap->pending_writes)==0);
		}
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	}
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	if (bitmap->flags & BITMAP_WRITE_ERROR)
		bitmap_file_kick(bitmap);
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}

static void end_bitmap_write(struct buffer_head *bh, int uptodate)
{
	struct bitmap *bitmap = bh->b_private;
	unsigned long flags;
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	if (!uptodate) {
		spin_lock_irqsave(&bitmap->lock, flags);
		bitmap->flags |= BITMAP_WRITE_ERROR;
		spin_unlock_irqrestore(&bitmap->lock, flags);
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	}
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	if (atomic_dec_and_test(&bitmap->pending_writes))
		wake_up(&bitmap->write_wait);
}
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/* copied from buffer.c */
static void
__clear_page_buffers(struct page *page)
{
	ClearPagePrivate(page);
	set_page_private(page, 0);
	page_cache_release(page);
}
static void free_buffers(struct page *page)
{
	struct buffer_head *bh = page_buffers(page);
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	while (bh) {
		struct buffer_head *next = bh->b_this_page;
		free_buffer_head(bh);
		bh = next;
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	}
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	__clear_page_buffers(page);
	put_page(page);
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}

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/* read a page from a file.
 * We both read the page, and attach buffers to the page to record the
 * address of each block (using bmap).  These addresses will be used
 * to write the block later, completely bypassing the filesystem.
 * This usage is similar to how swap files are handled, and allows us
 * to write to a file with no concerns of memory allocation failing.
 */
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static struct page *read_page(struct file *file, unsigned long index,
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			      struct bitmap *bitmap,
			      unsigned long count)
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{
	struct page *page = NULL;
J
Josef Sipek 已提交
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	struct inode *inode = file->f_path.dentry->d_inode;
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	struct buffer_head *bh;
	sector_t block;
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	PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_SIZE,
			(unsigned long long)index << PAGE_SHIFT);
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	page = alloc_page(GFP_KERNEL);
	if (!page)
		page = ERR_PTR(-ENOMEM);
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	if (IS_ERR(page))
		goto out;
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	bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
	if (!bh) {
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		put_page(page);
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		page = ERR_PTR(-ENOMEM);
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		goto out;
	}
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	attach_page_buffers(page, bh);
	block = index << (PAGE_SHIFT - inode->i_blkbits);
	while (bh) {
		if (count == 0)
			bh->b_blocknr = 0;
		else {
			bh->b_blocknr = bmap(inode, block);
			if (bh->b_blocknr == 0) {
				/* Cannot use this file! */
				free_buffers(page);
				page = ERR_PTR(-EINVAL);
				goto out;
			}
			bh->b_bdev = inode->i_sb->s_bdev;
			if (count < (1<<inode->i_blkbits))
				count = 0;
			else
				count -= (1<<inode->i_blkbits);

			bh->b_end_io = end_bitmap_write;
			bh->b_private = bitmap;
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			atomic_inc(&bitmap->pending_writes);
			set_buffer_locked(bh);
			set_buffer_mapped(bh);
			submit_bh(READ, bh);
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		}
		block++;
		bh = bh->b_this_page;
	}
	page->index = index;
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	wait_event(bitmap->write_wait,
		   atomic_read(&bitmap->pending_writes)==0);
	if (bitmap->flags & BITMAP_WRITE_ERROR) {
		free_buffers(page);
		page = ERR_PTR(-EIO);
	}
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out:
	if (IS_ERR(page))
		printk(KERN_ALERT "md: bitmap read error: (%dB @ %Lu): %ld\n",
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			(int)PAGE_SIZE,
			(unsigned long long)index << PAGE_SHIFT,
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			PTR_ERR(page));
	return page;
}

/*
 * bitmap file superblock operations
 */

/* update the event counter and sync the superblock to disk */
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void bitmap_update_sb(struct bitmap *bitmap)
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{
	bitmap_super_t *sb;
	unsigned long flags;

	if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
491
		return;
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	spin_lock_irqsave(&bitmap->lock, flags);
	if (!bitmap->sb_page) { /* no superblock */
		spin_unlock_irqrestore(&bitmap->lock, flags);
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		return;
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	}
	spin_unlock_irqrestore(&bitmap->lock, flags);
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	sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
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	sb->events = cpu_to_le64(bitmap->mddev->events);
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	if (bitmap->mddev->events < bitmap->events_cleared) {
		/* rocking back to read-only */
		bitmap->events_cleared = bitmap->mddev->events;
		sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
	}
505
	kunmap_atomic(sb, KM_USER0);
506
	write_page(bitmap, bitmap->sb_page, 1);
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}

/* print out the bitmap file superblock */
void bitmap_print_sb(struct bitmap *bitmap)
{
	bitmap_super_t *sb;

	if (!bitmap || !bitmap->sb_page)
		return;
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	sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
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	printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
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	printk(KERN_DEBUG "         magic: %08x\n", le32_to_cpu(sb->magic));
	printk(KERN_DEBUG "       version: %d\n", le32_to_cpu(sb->version));
	printk(KERN_DEBUG "          uuid: %08x.%08x.%08x.%08x\n",
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					*(__u32 *)(sb->uuid+0),
					*(__u32 *)(sb->uuid+4),
					*(__u32 *)(sb->uuid+8),
					*(__u32 *)(sb->uuid+12));
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	printk(KERN_DEBUG "        events: %llu\n",
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			(unsigned long long) le64_to_cpu(sb->events));
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	printk(KERN_DEBUG "events cleared: %llu\n",
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			(unsigned long long) le64_to_cpu(sb->events_cleared));
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	printk(KERN_DEBUG "         state: %08x\n", le32_to_cpu(sb->state));
	printk(KERN_DEBUG "     chunksize: %d B\n", le32_to_cpu(sb->chunksize));
	printk(KERN_DEBUG "  daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
	printk(KERN_DEBUG "     sync size: %llu KB\n",
			(unsigned long long)le64_to_cpu(sb->sync_size)/2);
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	printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
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	kunmap_atomic(sb, KM_USER0);
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}

/* read the superblock from the bitmap file and initialize some bitmap fields */
static int bitmap_read_sb(struct bitmap *bitmap)
{
	char *reason = NULL;
	bitmap_super_t *sb;
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	unsigned long chunksize, daemon_sleep, write_behind;
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	unsigned long long events;
	int err = -EINVAL;

	/* page 0 is the superblock, read it... */
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	if (bitmap->file) {
		loff_t isize = i_size_read(bitmap->file->f_mapping->host);
		int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;

		bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
	} else {
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		bitmap->sb_page = read_sb_page(bitmap->mddev,
					       bitmap->mddev->bitmap_info.offset,
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					       NULL,
					       0, sizeof(bitmap_super_t));
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	}
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	if (IS_ERR(bitmap->sb_page)) {
		err = PTR_ERR(bitmap->sb_page);
		bitmap->sb_page = NULL;
		return err;
	}

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	sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
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	chunksize = le32_to_cpu(sb->chunksize);
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	daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
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	write_behind = le32_to_cpu(sb->write_behind);
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	/* verify that the bitmap-specific fields are valid */
	if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
		reason = "bad magic";
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	else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
		 le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
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		reason = "unrecognized superblock version";
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	else if (chunksize < 512)
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		reason = "bitmap chunksize too small";
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	else if ((1 << ffz(~chunksize)) != chunksize)
		reason = "bitmap chunksize not a power of 2";
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	else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
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		reason = "daemon sleep period out of range";
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	else if (write_behind > COUNTER_MAX)
		reason = "write-behind limit out of range (0 - 16383)";
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	if (reason) {
		printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
			bmname(bitmap), reason);
		goto out;
	}

	/* keep the array size field of the bitmap superblock up to date */
	sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);

	if (!bitmap->mddev->persistent)
		goto success;

	/*
	 * if we have a persistent array superblock, compare the
	 * bitmap's UUID and event counter to the mddev's
	 */
	if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
		printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n",
			bmname(bitmap));
		goto out;
	}
	events = le64_to_cpu(sb->events);
	if (events < bitmap->mddev->events) {
		printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) "
			"-- forcing full recovery\n", bmname(bitmap), events,
			(unsigned long long) bitmap->mddev->events);
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		sb->state |= cpu_to_le32(BITMAP_STALE);
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	}
success:
	/* assign fields using values from superblock */
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	bitmap->mddev->bitmap_info.chunksize = chunksize;
	bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
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	bitmap->daemon_lastrun = jiffies;
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	bitmap->mddev->bitmap_info.max_write_behind = write_behind;
619
	bitmap->flags |= le32_to_cpu(sb->state);
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	if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
		bitmap->flags |= BITMAP_HOSTENDIAN;
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	bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
623
	if (sb->state & cpu_to_le32(BITMAP_STALE))
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		bitmap->events_cleared = bitmap->mddev->events;
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	err = 0;
out:
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	kunmap_atomic(sb, KM_USER0);
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	if (err)
		bitmap_print_sb(bitmap);
	return err;
}

enum bitmap_mask_op {
	MASK_SET,
	MASK_UNSET
};

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/* record the state of the bitmap in the superblock.  Return the old value */
static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
			     enum bitmap_mask_op op)
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{
	bitmap_super_t *sb;
	unsigned long flags;
644
	int old;
645 646

	spin_lock_irqsave(&bitmap->lock, flags);
647
	if (!bitmap->sb_page) { /* can't set the state */
648
		spin_unlock_irqrestore(&bitmap->lock, flags);
649
		return 0;
650 651
	}
	spin_unlock_irqrestore(&bitmap->lock, flags);
652
	sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
653
	old = le32_to_cpu(sb->state) & bits;
654
	switch (op) {
655
		case MASK_SET: sb->state |= cpu_to_le32(bits);
656
				break;
657
		case MASK_UNSET: sb->state &= cpu_to_le32(~bits);
658 659 660
				break;
		default: BUG();
	}
661
	kunmap_atomic(sb, KM_USER0);
662
	return old;
663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690
}

/*
 * general bitmap file operations
 */

/* calculate the index of the page that contains this bit */
static inline unsigned long file_page_index(unsigned long chunk)
{
	return CHUNK_BIT_OFFSET(chunk) >> PAGE_BIT_SHIFT;
}

/* calculate the (bit) offset of this bit within a page */
static inline unsigned long file_page_offset(unsigned long chunk)
{
	return CHUNK_BIT_OFFSET(chunk) & (PAGE_BITS - 1);
}

/*
 * return a pointer to the page in the filemap that contains the given bit
 *
 * this lookup is complicated by the fact that the bitmap sb might be exactly
 * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
 * 0 or page 1
 */
static inline struct page *filemap_get_page(struct bitmap *bitmap,
					unsigned long chunk)
{
691
	if (file_page_index(chunk) >= bitmap->file_pages) return NULL;
692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715
	return bitmap->filemap[file_page_index(chunk) - file_page_index(0)];
}


static void bitmap_file_unmap(struct bitmap *bitmap)
{
	struct page **map, *sb_page;
	unsigned long *attr;
	int pages;
	unsigned long flags;

	spin_lock_irqsave(&bitmap->lock, flags);
	map = bitmap->filemap;
	bitmap->filemap = NULL;
	attr = bitmap->filemap_attr;
	bitmap->filemap_attr = NULL;
	pages = bitmap->file_pages;
	bitmap->file_pages = 0;
	sb_page = bitmap->sb_page;
	bitmap->sb_page = NULL;
	spin_unlock_irqrestore(&bitmap->lock, flags);

	while (pages--)
		if (map[pages]->index != 0) /* 0 is sb_page, release it below */
716
			free_buffers(map[pages]);
717 718 719
	kfree(map);
	kfree(attr);

720 721
	if (sb_page)
		free_buffers(sb_page);
722 723 724 725 726 727 728 729 730 731 732 733
}

static void bitmap_file_put(struct bitmap *bitmap)
{
	struct file *file;
	unsigned long flags;

	spin_lock_irqsave(&bitmap->lock, flags);
	file = bitmap->file;
	bitmap->file = NULL;
	spin_unlock_irqrestore(&bitmap->lock, flags);

734 735 736
	if (file)
		wait_event(bitmap->write_wait,
			   atomic_read(&bitmap->pending_writes)==0);
737 738
	bitmap_file_unmap(bitmap);

739
	if (file) {
J
Josef Sipek 已提交
740
		struct inode *inode = file->f_path.dentry->d_inode;
741
		invalidate_mapping_pages(inode->i_mapping, 0, -1);
742
		fput(file);
743
	}
744 745 746 747 748 749 750 751 752 753 754 755
}


/*
 * bitmap_file_kick - if an error occurs while manipulating the bitmap file
 * then it is no longer reliable, so we stop using it and we mark the file
 * as failed in the superblock
 */
static void bitmap_file_kick(struct bitmap *bitmap)
{
	char *path, *ptr = NULL;

756 757
	if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) {
		bitmap_update_sb(bitmap);
758

759 760 761
		if (bitmap->file) {
			path = kmalloc(PAGE_SIZE, GFP_KERNEL);
			if (path)
C
Christoph Hellwig 已提交
762 763 764
				ptr = d_path(&bitmap->file->f_path, path,
					     PAGE_SIZE);

765

766 767
			printk(KERN_ALERT
			      "%s: kicking failed bitmap file %s from array!\n",
C
Christoph Hellwig 已提交
768
			      bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
769

770 771 772 773 774
			kfree(path);
		} else
			printk(KERN_ALERT
			       "%s: disabling internal bitmap due to errors\n",
			       bmname(bitmap));
775
	}
776 777 778 779 780 781 782

	bitmap_file_put(bitmap);

	return;
}

enum bitmap_page_attr {
783 784 785
	BITMAP_PAGE_DIRTY = 0, // there are set bits that need to be synced
	BITMAP_PAGE_CLEAN = 1, // there are bits that might need to be cleared
	BITMAP_PAGE_NEEDWRITE=2, // there are cleared bits that need to be synced
786 787 788 789 790
};

static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
				enum bitmap_page_attr attr)
{
791
	__set_bit((page->index<<2) + attr, bitmap->filemap_attr);
792 793 794 795 796
}

static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
				enum bitmap_page_attr attr)
{
797
	__clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
798 799
}

800 801
static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
					   enum bitmap_page_attr attr)
802
{
803
	return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819
}

/*
 * bitmap_file_set_bit -- called before performing a write to the md device
 * to set (and eventually sync) a particular bit in the bitmap file
 *
 * we set the bit immediately, then we record the page number so that
 * when an unplug occurs, we can flush the dirty pages out to disk
 */
static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
{
	unsigned long bit;
	struct page *page;
	void *kaddr;
	unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);

820
	if (!bitmap->filemap) {
821 822 823 824
		return;
	}

	page = filemap_get_page(bitmap, chunk);
825
	if (!page) return;
826 827 828 829
	bit = file_page_offset(chunk);

 	/* set the bit */
	kaddr = kmap_atomic(page, KM_USER0);
830 831 832 833
	if (bitmap->flags & BITMAP_HOSTENDIAN)
		set_bit(bit, kaddr);
	else
		ext2_set_bit(bit, kaddr);
834 835 836 837 838 839 840 841 842 843 844
	kunmap_atomic(kaddr, KM_USER0);
	PRINTK("set file bit %lu page %lu\n", bit, page->index);

	/* record page number so it gets flushed to disk when unplug occurs */
	set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);

}

/* this gets called when the md device is ready to unplug its underlying
 * (slave) device queues -- before we let any writes go down, we need to
 * sync the dirty pages of the bitmap file to disk */
845
void bitmap_unplug(struct bitmap *bitmap)
846
{
847 848
	unsigned long i, flags;
	int dirty, need_write;
849 850 851 852
	struct page *page;
	int wait = 0;

	if (!bitmap)
853
		return;
854 855 856 857 858

	/* look at each page to see if there are any set bits that need to be
	 * flushed out to disk */
	for (i = 0; i < bitmap->file_pages; i++) {
		spin_lock_irqsave(&bitmap->lock, flags);
859
		if (!bitmap->filemap) {
860
			spin_unlock_irqrestore(&bitmap->lock, flags);
861
			return;
862 863
		}
		page = bitmap->filemap[i];
864 865
		dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
		need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
866 867
		clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
		clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
868
		if (dirty)
869 870 871
			wait = 1;
		spin_unlock_irqrestore(&bitmap->lock, flags);

872
		if (dirty | need_write)
873
			write_page(bitmap, page, 0);
874 875
	}
	if (wait) { /* if any writes were performed, we need to wait on them */
876
		if (bitmap->file)
877 878
			wait_event(bitmap->write_wait,
				   atomic_read(&bitmap->pending_writes)==0);
879
		else
880
			md_super_wait(bitmap->mddev);
881
	}
882 883
	if (bitmap->flags & BITMAP_WRITE_ERROR)
		bitmap_file_kick(bitmap);
884 885
}

886
static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
887 888 889 890 891 892 893
/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
 * the in-memory bitmap from the on-disk bitmap -- also, sets up the
 * memory mapping of the bitmap file
 * Special cases:
 *   if there's no bitmap file, or if the bitmap file had been
 *   previously kicked from the array, we mark all the bits as
 *   1's in order to cause a full resync.
894 895 896
 *
 * We ignore all bits for sectors that end earlier than 'start'.
 * This is used when reading an out-of-date bitmap...
897
 */
898
static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
899 900 901 902 903
{
	unsigned long i, chunks, index, oldindex, bit;
	struct page *page = NULL, *oldpage = NULL;
	unsigned long num_pages, bit_cnt = 0;
	struct file *file;
904
	unsigned long bytes, offset;
905 906
	int outofdate;
	int ret = -ENOSPC;
907
	void *paddr;
908 909 910 911

	chunks = bitmap->chunks;
	file = bitmap->file;

912
	BUG_ON(!file && !bitmap->mddev->bitmap_info.offset);
913

914
#ifdef INJECT_FAULTS_3
915 916 917 918 919 920 921 922 923
	outofdate = 1;
#else
	outofdate = bitmap->flags & BITMAP_STALE;
#endif
	if (outofdate)
		printk(KERN_INFO "%s: bitmap file is out of date, doing full "
			"recovery\n", bmname(bitmap));

	bytes = (chunks + 7) / 8;
924

925
	num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE;
926

927
	if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
928 929 930 931
		printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
			bmname(bitmap),
			(unsigned long) i_size_read(file->f_mapping->host),
			bytes + sizeof(bitmap_super_t));
932
		goto err;
933
	}
934 935 936

	ret = -ENOMEM;

937
	bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
938
	if (!bitmap->filemap)
939
		goto err;
940

941 942
	/* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
	bitmap->filemap_attr = kzalloc(
943
		roundup( DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
944
		GFP_KERNEL);
945
	if (!bitmap->filemap_attr)
946
		goto err;
947 948 949 950

	oldindex = ~0L;

	for (i = 0; i < chunks; i++) {
951
		int b;
952 953 954
		index = file_page_index(i);
		bit = file_page_offset(i);
		if (index != oldindex) { /* this is a new page, read it in */
955
			int count;
956
			/* unmap the old page, we're done with it */
957
			if (index == num_pages-1)
958 959
				count = bytes + sizeof(bitmap_super_t)
					- index * PAGE_SIZE;
960 961
			else
				count = PAGE_SIZE;
962 963 964 965 966 967 968 969
			if (index == 0) {
				/*
				 * if we're here then the superblock page
				 * contains some bits (PAGE_SIZE != sizeof sb)
				 * we've already read it in, so just use it
				 */
				page = bitmap->sb_page;
				offset = sizeof(bitmap_super_t);
N
NeilBrown 已提交
970 971
				if (!file)
					read_sb_page(bitmap->mddev,
972
						     bitmap->mddev->bitmap_info.offset,
N
NeilBrown 已提交
973 974
						     page,
						     index, count);
975
			} else if (file) {
976
				page = read_page(file, index, bitmap, count);
977 978
				offset = 0;
			} else {
979 980
				page = read_sb_page(bitmap->mddev,
						    bitmap->mddev->bitmap_info.offset,
981 982
						    NULL,
						    index, count);
983 984
				offset = 0;
			}
985 986
			if (IS_ERR(page)) { /* read error */
				ret = PTR_ERR(page);
987
				goto err;
988 989
			}

990 991 992
			oldindex = index;
			oldpage = page;

993 994 995
			bitmap->filemap[bitmap->file_pages++] = page;
			bitmap->last_page_size = count;

996 997 998 999 1000
			if (outofdate) {
				/*
				 * if bitmap is out of date, dirty the
			 	 * whole page and write it out
				 */
1001 1002
				paddr = kmap_atomic(page, KM_USER0);
				memset(paddr + offset, 0xff,
1003
				       PAGE_SIZE - offset);
1004
				kunmap_atomic(paddr, KM_USER0);
1005 1006 1007
				write_page(bitmap, page, 1);

				ret = -EIO;
1008
				if (bitmap->flags & BITMAP_WRITE_ERROR)
1009
					goto err;
1010 1011
			}
		}
1012
		paddr = kmap_atomic(page, KM_USER0);
1013
		if (bitmap->flags & BITMAP_HOSTENDIAN)
1014
			b = test_bit(bit, paddr);
1015
		else
1016 1017
			b = ext2_test_bit(bit, paddr);
		kunmap_atomic(paddr, KM_USER0);
1018
		if (b) {
1019
			/* if the disk bit is set, set the memory bit */
1020 1021 1022 1023 1024
			int needed = ((sector_t)(i+1) << (CHUNK_BLOCK_SHIFT(bitmap))
				      >= start);
			bitmap_set_memory_bits(bitmap,
					       (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap),
					       needed);
1025
			bit_cnt++;
1026
			set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039
		}
	}

 	/* everything went OK */
	ret = 0;
	bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);

	if (bit_cnt) { /* Kick recovery if any bits were set */
		set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
		md_wakeup_thread(bitmap->mddev->thread);
	}

	printk(KERN_INFO "%s: bitmap initialized from disk: "
1040 1041 1042 1043
		"read %lu/%lu pages, set %lu bits\n",
		bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt);

	return 0;
1044

1045 1046 1047
 err:
	printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
	       bmname(bitmap), ret);
1048 1049 1050
	return ret;
}

1051 1052 1053 1054 1055
void bitmap_write_all(struct bitmap *bitmap)
{
	/* We don't actually write all bitmap blocks here,
	 * just flag them as needing to be written
	 */
1056
	int i;
1057

1058 1059 1060
	for (i=0; i < bitmap->file_pages; i++)
		set_page_attr(bitmap, bitmap->filemap[i],
			      BITMAP_PAGE_NEEDWRITE);
1061 1062
}

1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083

static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
{
	sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
	bitmap->bp[page].count += inc;
/*
	if (page == 0) printk("count page 0, offset %llu: %d gives %d\n",
			      (unsigned long long)offset, inc, bitmap->bp[page].count);
*/
	bitmap_checkfree(bitmap, page);
}
static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
					    sector_t offset, int *blocks,
					    int create);

/*
 * bitmap daemon -- periodically wakes up to clean bits and flush pages
 *			out to disk
 */

1084
void bitmap_daemon_work(mddev_t *mddev)
1085
{
1086
	struct bitmap *bitmap;
1087
	unsigned long j;
1088 1089 1090
	unsigned long flags;
	struct page *page = NULL, *lastpage = NULL;
	int blocks;
1091
	void *paddr;
1092

1093 1094 1095
	/* Use a mutex to guard daemon_work against
	 * bitmap_destroy.
	 */
1096
	mutex_lock(&mddev->bitmap_info.mutex);
1097 1098
	bitmap = mddev->bitmap;
	if (bitmap == NULL) {
1099
		mutex_unlock(&mddev->bitmap_info.mutex);
1100
		return;
1101
	}
1102
	if (time_before(jiffies, bitmap->daemon_lastrun
1103
			+ bitmap->mddev->bitmap_info.daemon_sleep))
1104 1105
		goto done;

1106
	bitmap->daemon_lastrun = jiffies;
1107 1108
	if (bitmap->allclean) {
		bitmap->mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1109
		goto done;
1110 1111
	}
	bitmap->allclean = 1;
1112

1113
	spin_lock_irqsave(&bitmap->lock, flags);
1114 1115
	for (j = 0; j < bitmap->chunks; j++) {
		bitmap_counter_t *bmc;
1116
		if (!bitmap->filemap)
1117 1118 1119 1120 1121 1122
			/* error or shutdown */
			break;

		page = filemap_get_page(bitmap, j);

		if (page != lastpage) {
1123
			/* skip this page unless it's marked as needing cleaning */
1124 1125 1126
			if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
				int need_write = test_page_attr(bitmap, page,
								BITMAP_PAGE_NEEDWRITE);
1127
				if (need_write)
1128
					clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1129

1130
				spin_unlock_irqrestore(&bitmap->lock, flags);
1131
				if (need_write) {
1132
					write_page(bitmap, page, 0);
1133 1134
					bitmap->allclean = 0;
				}
1135 1136
				spin_lock_irqsave(&bitmap->lock, flags);
				j |= (PAGE_BITS - 1);
1137 1138 1139
				continue;
			}

1140 1141
			/* grab the new page, sync and release the old */
			if (lastpage != NULL) {
1142
				if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1143 1144
					clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
					spin_unlock_irqrestore(&bitmap->lock, flags);
1145
					write_page(bitmap, lastpage, 0);
1146 1147 1148 1149 1150 1151 1152
				} else {
					set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
					spin_unlock_irqrestore(&bitmap->lock, flags);
				}
			} else
				spin_unlock_irqrestore(&bitmap->lock, flags);
			lastpage = page;
1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165

			/* We are possibly going to clear some bits, so make
			 * sure that events_cleared is up-to-date.
			 */
			if (bitmap->need_sync) {
				bitmap_super_t *sb;
				bitmap->need_sync = 0;
				sb = kmap_atomic(bitmap->sb_page, KM_USER0);
				sb->events_cleared =
					cpu_to_le64(bitmap->events_cleared);
				kunmap_atomic(sb, KM_USER0);
				write_page(bitmap, bitmap->sb_page, 1);
			}
1166 1167 1168
			spin_lock_irqsave(&bitmap->lock, flags);
			clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
		}
1169 1170 1171
		bmc = bitmap_get_counter(bitmap,
					 (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
					 &blocks, 0);
1172 1173 1174 1175
		if (bmc) {
/*
  if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc);
*/
1176 1177 1178
			if (*bmc)
				bitmap->allclean = 0;

1179 1180 1181 1182 1183 1184
			if (*bmc == 2) {
				*bmc=1; /* maybe clear the bit next time */
				set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
			} else if (*bmc == 1) {
				/* we can clear the bit */
				*bmc = 0;
1185 1186
				bitmap_count_page(bitmap,
						  (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
1187 1188 1189
						  -1);

				/* clear the bit */
1190
				paddr = kmap_atomic(page, KM_USER0);
1191
				if (bitmap->flags & BITMAP_HOSTENDIAN)
1192
					clear_bit(file_page_offset(j), paddr);
1193
				else
1194 1195
					ext2_clear_bit(file_page_offset(j), paddr);
				kunmap_atomic(paddr, KM_USER0);
1196
			}
1197 1198
		} else
			j |= PAGE_COUNTER_MASK;
1199
	}
1200
	spin_unlock_irqrestore(&bitmap->lock, flags);
1201 1202 1203 1204

	/* now sync the final page */
	if (lastpage != NULL) {
		spin_lock_irqsave(&bitmap->lock, flags);
1205
		if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1206 1207
			clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
			spin_unlock_irqrestore(&bitmap->lock, flags);
1208
			write_page(bitmap, lastpage, 0);
1209 1210 1211 1212 1213 1214
		} else {
			set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
			spin_unlock_irqrestore(&bitmap->lock, flags);
		}
	}

1215
 done:
1216
	if (bitmap->allclean == 0)
1217
		bitmap->mddev->thread->timeout = 
1218
			bitmap->mddev->bitmap_info.daemon_sleep;
1219
	mutex_unlock(&mddev->bitmap_info.mutex);
1220 1221 1222 1223 1224
}

static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
					    sector_t offset, int *blocks,
					    int create)
1225 1226
__releases(bitmap->lock)
__acquires(bitmap->lock)
1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260
{
	/* If 'create', we might release the lock and reclaim it.
	 * The lock must have been taken with interrupts enabled.
	 * If !create, we don't release the lock.
	 */
	sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap);
	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
	unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
	sector_t csize;

	if (bitmap_checkpage(bitmap, page, create) < 0) {
		csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
		*blocks = csize - (offset & (csize- 1));
		return NULL;
	}
	/* now locked ... */

	if (bitmap->bp[page].hijacked) { /* hijacked pointer */
		/* should we use the first or second counter field
		 * of the hijacked pointer? */
		int hi = (pageoff > PAGE_COUNTER_MASK);
		csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) +
					  PAGE_COUNTER_SHIFT - 1);
		*blocks = csize - (offset & (csize- 1));
		return  &((bitmap_counter_t *)
			  &bitmap->bp[page].map)[hi];
	} else { /* page is allocated */
		csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap));
		*blocks = csize - (offset & (csize- 1));
		return (bitmap_counter_t *)
			&(bitmap->bp[page].map[pageoff]);
	}
}

1261
int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1262 1263
{
	if (!bitmap) return 0;
1264 1265 1266 1267 1268 1269 1270

	if (behind) {
		atomic_inc(&bitmap->behind_writes);
		PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n",
		  atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
	}

1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281
	while (sectors) {
		int blocks;
		bitmap_counter_t *bmc;

		spin_lock_irq(&bitmap->lock);
		bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
		if (!bmc) {
			spin_unlock_irq(&bitmap->lock);
			return 0;
		}

1282 1283 1284 1285 1286 1287 1288 1289 1290
		if (unlikely((*bmc & COUNTER_MAX) == COUNTER_MAX)) {
			DEFINE_WAIT(__wait);
			/* note that it is safe to do the prepare_to_wait
			 * after the test as long as we do it before dropping
			 * the spinlock.
			 */
			prepare_to_wait(&bitmap->overflow_wait, &__wait,
					TASK_UNINTERRUPTIBLE);
			spin_unlock_irq(&bitmap->lock);
1291
			blk_unplug(bitmap->mddev->queue);
1292 1293 1294 1295 1296
			schedule();
			finish_wait(&bitmap->overflow_wait, &__wait);
			continue;
		}

1297 1298 1299 1300
		switch(*bmc) {
		case 0:
			bitmap_file_set_bit(bitmap, offset);
			bitmap_count_page(bitmap,offset, 1);
1301
			blk_plug_device_unlocked(bitmap->mddev->queue);
1302 1303 1304 1305
			/* fall through */
		case 1:
			*bmc = 2;
		}
1306

1307 1308 1309 1310 1311 1312 1313 1314 1315
		(*bmc)++;

		spin_unlock_irq(&bitmap->lock);

		offset += blocks;
		if (sectors > blocks)
			sectors -= blocks;
		else sectors = 0;
	}
1316
	bitmap->allclean = 0;
1317 1318 1319 1320
	return 0;
}

void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1321
		     int success, int behind)
1322 1323
{
	if (!bitmap) return;
1324 1325 1326 1327 1328
	if (behind) {
		atomic_dec(&bitmap->behind_writes);
		PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n",
		  atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
	}
1329 1330 1331
	if (bitmap->mddev->degraded)
		/* Never clear bits or update events_cleared when degraded */
		success = 0;
1332

1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344
	while (sectors) {
		int blocks;
		unsigned long flags;
		bitmap_counter_t *bmc;

		spin_lock_irqsave(&bitmap->lock, flags);
		bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
		if (!bmc) {
			spin_unlock_irqrestore(&bitmap->lock, flags);
			return;
		}

1345 1346 1347 1348 1349 1350
		if (success &&
		    bitmap->events_cleared < bitmap->mddev->events) {
			bitmap->events_cleared = bitmap->mddev->events;
			bitmap->need_sync = 1;
		}

1351 1352 1353
		if (!success && ! (*bmc & NEEDED_MASK))
			*bmc |= NEEDED_MASK;

1354 1355 1356
		if ((*bmc & COUNTER_MAX) == COUNTER_MAX)
			wake_up(&bitmap->overflow_wait);

1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370
		(*bmc)--;
		if (*bmc <= 2) {
			set_page_attr(bitmap,
				      filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
				      BITMAP_PAGE_CLEAN);
		}
		spin_unlock_irqrestore(&bitmap->lock, flags);
		offset += blocks;
		if (sectors > blocks)
			sectors -= blocks;
		else sectors = 0;
	}
}

1371 1372
static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks,
			       int degraded)
1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388
{
	bitmap_counter_t *bmc;
	int rv;
	if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
		*blocks = 1024;
		return 1; /* always resync if no bitmap */
	}
	spin_lock_irq(&bitmap->lock);
	bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
	rv = 0;
	if (bmc) {
		/* locked */
		if (RESYNC(*bmc))
			rv = 1;
		else if (NEEDED(*bmc)) {
			rv = 1;
1389 1390 1391 1392
			if (!degraded) { /* don't set/clear bits if degraded */
				*bmc |= RESYNC_MASK;
				*bmc &= ~NEEDED_MASK;
			}
1393 1394 1395
		}
	}
	spin_unlock_irq(&bitmap->lock);
1396
	bitmap->allclean = 0;
1397 1398 1399
	return rv;
}

1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422
int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks,
		      int degraded)
{
	/* bitmap_start_sync must always report on multiples of whole
	 * pages, otherwise resync (which is very PAGE_SIZE based) will
	 * get confused.
	 * So call __bitmap_start_sync repeatedly (if needed) until
	 * At least PAGE_SIZE>>9 blocks are covered.
	 * Return the 'or' of the result.
	 */
	int rv = 0;
	int blocks1;

	*blocks = 0;
	while (*blocks < (PAGE_SIZE>>9)) {
		rv |= __bitmap_start_sync(bitmap, offset,
					  &blocks1, degraded);
		offset += blocks1;
		*blocks += blocks1;
	}
	return rv;
}

1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455
void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted)
{
	bitmap_counter_t *bmc;
	unsigned long flags;
/*
	if (offset == 0) printk("bitmap_end_sync 0 (%d)\n", aborted);
*/	if (bitmap == NULL) {
		*blocks = 1024;
		return;
	}
	spin_lock_irqsave(&bitmap->lock, flags);
	bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
	if (bmc == NULL)
		goto unlock;
	/* locked */
/*
	if (offset == 0) printk("bitmap_end sync found 0x%x, blocks %d\n", *bmc, *blocks);
*/
	if (RESYNC(*bmc)) {
		*bmc &= ~RESYNC_MASK;

		if (!NEEDED(*bmc) && aborted)
			*bmc |= NEEDED_MASK;
		else {
			if (*bmc <= 2) {
				set_page_attr(bitmap,
					      filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
					      BITMAP_PAGE_CLEAN);
			}
		}
	}
 unlock:
	spin_unlock_irqrestore(&bitmap->lock, flags);
1456
	bitmap->allclean = 0;
1457 1458 1459 1460 1461 1462 1463 1464 1465 1466
}

void bitmap_close_sync(struct bitmap *bitmap)
{
	/* Sync has finished, and any bitmap chunks that weren't synced
	 * properly have been aborted.  It remains to us to clear the
	 * RESYNC bit wherever it is still on
	 */
	sector_t sector = 0;
	int blocks;
N
NeilBrown 已提交
1467 1468
	if (!bitmap)
		return;
1469 1470
	while (sector < bitmap->mddev->resync_max_sectors) {
		bitmap_end_sync(bitmap, sector, &blocks, 0);
N
NeilBrown 已提交
1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486
		sector += blocks;
	}
}

void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
{
	sector_t s = 0;
	int blocks;

	if (!bitmap)
		return;
	if (sector == 0) {
		bitmap->last_end_sync = jiffies;
		return;
	}
	if (time_before(jiffies, (bitmap->last_end_sync
1487
				  + bitmap->mddev->bitmap_info.daemon_sleep)))
N
NeilBrown 已提交
1488 1489 1490 1491
		return;
	wait_event(bitmap->mddev->recovery_wait,
		   atomic_read(&bitmap->mddev->recovery_active) == 0);

1492 1493
	bitmap->mddev->curr_resync_completed = bitmap->mddev->curr_resync;
	set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
N
NeilBrown 已提交
1494 1495 1496 1497 1498
	sector &= ~((1ULL << CHUNK_BLOCK_SHIFT(bitmap)) - 1);
	s = 0;
	while (s < sector && s < bitmap->mddev->resync_max_sectors) {
		bitmap_end_sync(bitmap, s, &blocks, 0);
		s += blocks;
1499
	}
N
NeilBrown 已提交
1500
	bitmap->last_end_sync = jiffies;
1501
	sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1502 1503
}

1504
static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1505 1506
{
	/* For each chunk covered by any of these sectors, set the
1507
	 * counter to 1 and set resync_needed.  They should all
1508 1509
	 * be 0 at this point
	 */
1510 1511 1512 1513 1514 1515

	int secs;
	bitmap_counter_t *bmc;
	spin_lock_irq(&bitmap->lock);
	bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
	if (!bmc) {
1516
		spin_unlock_irq(&bitmap->lock);
1517
		return;
1518
	}
1519 1520
	if (! *bmc) {
		struct page *page;
1521
		*bmc = 1 | (needed?NEEDED_MASK:0);
1522 1523 1524 1525 1526
		bitmap_count_page(bitmap, offset, 1);
		page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
		set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
	}
	spin_unlock_irq(&bitmap->lock);
1527
	bitmap->allclean = 0;
1528 1529
}

1530 1531 1532 1533 1534 1535
/* dirty the memory and file bits for bitmap chunks "s" to "e" */
void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
{
	unsigned long chunk;

	for (chunk = s; chunk <= e; chunk++) {
1536
		sector_t sec = (sector_t)chunk << CHUNK_BLOCK_SHIFT(bitmap);
1537 1538 1539 1540 1541
		bitmap_set_memory_bits(bitmap, sec, 1);
		bitmap_file_set_bit(bitmap, sec);
	}
}

1542 1543 1544 1545 1546 1547
/*
 * flush out any pending updates
 */
void bitmap_flush(mddev_t *mddev)
{
	struct bitmap *bitmap = mddev->bitmap;
1548
	long sleep;
1549 1550 1551 1552 1553 1554 1555

	if (!bitmap) /* there was no bitmap */
		return;

	/* run the daemon_work three time to ensure everything is flushed
	 * that can be
	 */
1556
	sleep = mddev->bitmap_info.daemon_sleep * 2;
1557
	bitmap->daemon_lastrun -= sleep;
1558
	bitmap_daemon_work(mddev);
1559
	bitmap->daemon_lastrun -= sleep;
1560
	bitmap_daemon_work(mddev);
1561
	bitmap->daemon_lastrun -= sleep;
1562
	bitmap_daemon_work(mddev);
1563 1564 1565
	bitmap_update_sb(bitmap);
}

1566 1567 1568
/*
 * free memory that was allocated
 */
1569
static void bitmap_free(struct bitmap *bitmap)
1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591
{
	unsigned long k, pages;
	struct bitmap_page *bp;

	if (!bitmap) /* there was no bitmap */
		return;

	/* release the bitmap file and kill the daemon */
	bitmap_file_put(bitmap);

	bp = bitmap->bp;
	pages = bitmap->pages;

	/* free all allocated memory */

	if (bp) /* deallocate the page memory */
		for (k = 0; k < pages; k++)
			if (bp[k].map && !bp[k].hijacked)
				kfree(bp[k].map);
	kfree(bp);
	kfree(bitmap);
}
1592

1593 1594 1595 1596 1597 1598 1599
void bitmap_destroy(mddev_t *mddev)
{
	struct bitmap *bitmap = mddev->bitmap;

	if (!bitmap) /* there was no bitmap */
		return;

1600
	mutex_lock(&mddev->bitmap_info.mutex);
1601
	mddev->bitmap = NULL; /* disconnect from the md device */
1602
	mutex_unlock(&mddev->bitmap_info.mutex);
1603 1604
	if (mddev->thread)
		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1605 1606 1607

	bitmap_free(bitmap);
}
1608 1609 1610 1611 1612 1613 1614 1615

/*
 * initialize the bitmap structure
 * if this returns an error, bitmap_destroy must be called to do clean up
 */
int bitmap_create(mddev_t *mddev)
{
	struct bitmap *bitmap;
1616
	sector_t blocks = mddev->resync_max_sectors;
1617 1618
	unsigned long chunks;
	unsigned long pages;
1619
	struct file *file = mddev->bitmap_info.file;
1620
	int err;
1621
	sector_t start;
1622

A
Alexey Dobriyan 已提交
1623
	BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1624

1625
	if (!file && !mddev->bitmap_info.offset) /* bitmap disabled, nothing to do */
1626 1627
		return 0;

1628
	BUG_ON(file && mddev->bitmap_info.offset);
1629

1630
	bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1631 1632 1633 1634
	if (!bitmap)
		return -ENOMEM;

	spin_lock_init(&bitmap->lock);
1635 1636
	atomic_set(&bitmap->pending_writes, 0);
	init_waitqueue_head(&bitmap->write_wait);
1637
	init_waitqueue_head(&bitmap->overflow_wait);
1638

1639 1640 1641
	bitmap->mddev = mddev;

	bitmap->file = file;
1642 1643
	if (file) {
		get_file(file);
1644 1645 1646 1647 1648
		/* As future accesses to this file will use bmap,
		 * and bypass the page cache, we must sync the file
		 * first.
		 */
		vfs_fsync(file, file->f_dentry, 1);
1649
	}
1650
	/* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1651 1652
	err = bitmap_read_sb(bitmap);
	if (err)
1653
		goto error;
1654

1655
	bitmap->chunkshift = ffz(~mddev->bitmap_info.chunksize);
1656 1657

	/* now that chunksize and chunkshift are set, we can use these macros */
1658 1659
 	chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) >>
			CHUNK_BLOCK_SHIFT(bitmap);
1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670
 	pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;

	BUG_ON(!pages);

	bitmap->chunks = chunks;
	bitmap->pages = pages;
	bitmap->missing_pages = pages;
	bitmap->counter_bits = COUNTER_BITS;

	bitmap->syncchunk = ~0UL;

1671
#ifdef INJECT_FATAL_FAULT_1
1672 1673
	bitmap->bp = NULL;
#else
1674
	bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1675
#endif
1676
	err = -ENOMEM;
1677
	if (!bitmap->bp)
1678
		goto error;
1679 1680 1681

	/* now that we have some pages available, initialize the in-memory
	 * bitmap from the on-disk bitmap */
1682 1683 1684 1685 1686 1687
	start = 0;
	if (mddev->degraded == 0
	    || bitmap->events_cleared == mddev->events)
		/* no need to keep dirty bits to optimise a re-add of a missing device */
		start = mddev->recovery_cp;
	err = bitmap_init_from_disk(bitmap, start);
1688

1689
	if (err)
1690
		goto error;
1691 1692 1693 1694

	printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
		pages, bmname(bitmap));

1695 1696
	mddev->bitmap = bitmap;

1697
	mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1698
	md_wakeup_thread(mddev->thread);
1699

1700 1701 1702
	bitmap_update_sb(bitmap);

	return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
1703 1704 1705 1706

 error:
	bitmap_free(bitmap);
	return err;
1707 1708 1709 1710 1711 1712 1713 1714 1715
}

/* the bitmap API -- for raid personalities */
EXPORT_SYMBOL(bitmap_startwrite);
EXPORT_SYMBOL(bitmap_endwrite);
EXPORT_SYMBOL(bitmap_start_sync);
EXPORT_SYMBOL(bitmap_end_sync);
EXPORT_SYMBOL(bitmap_unplug);
EXPORT_SYMBOL(bitmap_close_sync);
N
NeilBrown 已提交
1716
EXPORT_SYMBOL(bitmap_cond_end_sync);