bitmap.c 41.5 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.
 */

#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>
#include <linux/raid/md.h>
#include <linux/raid/bitmap.h>

/* 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)
{
	unsigned char *mappage;

	if (page >= bitmap->pages) {
		printk(KERN_ALERT
			"%s: invalid bitmap page request: %lu (> %lu)\n",
			bmname(bitmap), page, bitmap->pages-1);
		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
 */

/* copy the pathname of a file to a buffer */
char *file_path(struct file *file, char *buf, int count)
{
	if (!buf)
		return NULL;

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	buf = d_path(&file->f_path, buf, count);
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	return IS_ERR(buf) ? NULL : buf;
}

/*
 * basic page I/O operations
 */

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

	mdk_rdev_t *rdev;
	struct list_head *tmp;
	struct page *page = alloc_page(GFP_KERNEL);
	sector_t target;

	if (!page)
		return ERR_PTR(-ENOMEM);

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	rdev_for_each(rdev, tmp, mddev) {
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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_offset << 1) + offset + index * (PAGE_SIZE/512);

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		if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
			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 int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
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{
	mdk_rdev_t *rdev;
	struct list_head *tmp;
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	mddev_t *mddev = bitmap->mddev;
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	rdev_for_each(rdev, tmp, mddev)
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		if (test_bit(In_sync, &rdev->flags)
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		    && !test_bit(Faulty, &rdev->flags)) {
			int size = PAGE_SIZE;
			if (page->index == bitmap->file_pages-1)
				size = roundup(bitmap->last_page_size,
					       bdev_hardsect_size(rdev->bdev));
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			/* Just make sure we aren't corrupting data or
			 * metadata
			 */
			if (bitmap->offset < 0) {
				/* DATA  BITMAP METADATA  */
				if (bitmap->offset
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				    + (long)(page->index * (PAGE_SIZE/512))
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				    + size/512 > 0)
					/* bitmap runs in to metadata */
					return -EINVAL;
				if (rdev->data_offset + mddev->size*2
				    > rdev->sb_offset*2 + bitmap->offset)
					/* data runs in to bitmap */
					return -EINVAL;
			} else if (rdev->sb_offset*2 < rdev->data_offset) {
				/* METADATA BITMAP DATA */
				if (rdev->sb_offset*2
				    + bitmap->offset
				    + page->index*(PAGE_SIZE/512) + size/512
				    > rdev->data_offset)
					/* bitmap runs in to data */
					return -EINVAL;
			} else {
				/* DATA METADATA BITMAP - no problems */
			}
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			md_super_write(mddev, rdev,
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				       (rdev->sb_offset<<1) + bitmap->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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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 */
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		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);
	if (!bitmap->mddev->degraded)
		sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
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	kunmap_atomic(sb, KM_USER0);
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	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->offset, 0);
	}
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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);
	daemon_sleep = le32_to_cpu(sb->daemon_sleep);
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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 < PAGE_SIZE)
		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 / HZ)
		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 */
	bitmap->chunksize = chunksize;
	bitmap->daemon_sleep = daemon_sleep;
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	bitmap->daemon_lastrun = jiffies;
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	bitmap->max_write_behind = write_behind;
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	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);
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	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;
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	int old;
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	spin_lock_irqsave(&bitmap->lock, flags);
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	if (!bitmap->sb_page) { /* can't set the state */
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		spin_unlock_irqrestore(&bitmap->lock, flags);
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		return 0;
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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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	old = le32_to_cpu(sb->state) & bits;
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	switch (op) {
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		case MASK_SET: sb->state |= cpu_to_le32(bits);
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				break;
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		case MASK_UNSET: sb->state &= cpu_to_le32(~bits);
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				break;
		default: BUG();
	}
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	kunmap_atomic(sb, KM_USER0);
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	return old;
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}

/*
 * 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)
{
653
	if (file_page_index(chunk) >= bitmap->file_pages) return NULL;
654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677
	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 */
678
			free_buffers(map[pages]);
679 680 681
	kfree(map);
	kfree(attr);

682 683
	if (sb_page)
		free_buffers(sb_page);
684 685 686 687 688 689 690 691 692 693 694 695
}

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);

696 697 698
	if (file)
		wait_event(bitmap->write_wait,
			   atomic_read(&bitmap->pending_writes)==0);
699 700
	bitmap_file_unmap(bitmap);

701
	if (file) {
J
Josef Sipek 已提交
702
		struct inode *inode = file->f_path.dentry->d_inode;
703
		invalidate_mapping_pages(inode->i_mapping, 0, -1);
704
		fput(file);
705
	}
706 707 708 709 710 711 712 713 714 715 716 717
}


/*
 * 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;

718 719
	if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) {
		bitmap_update_sb(bitmap);
720

721 722 723 724
		if (bitmap->file) {
			path = kmalloc(PAGE_SIZE, GFP_KERNEL);
			if (path)
				ptr = file_path(bitmap->file, path, PAGE_SIZE);
725

726 727 728
			printk(KERN_ALERT
			      "%s: kicking failed bitmap file %s from array!\n",
			      bmname(bitmap), ptr ? ptr : "");
729

730 731 732 733 734
			kfree(path);
		} else
			printk(KERN_ALERT
			       "%s: disabling internal bitmap due to errors\n",
			       bmname(bitmap));
735
	}
736 737 738 739 740 741 742

	bitmap_file_put(bitmap);

	return;
}

enum bitmap_page_attr {
743 744 745
	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
746 747 748 749 750
};

static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
				enum bitmap_page_attr attr)
{
751
	__set_bit((page->index<<2) + attr, bitmap->filemap_attr);
752 753 754 755 756
}

static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
				enum bitmap_page_attr attr)
{
757
	__clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
758 759
}

760 761
static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
					   enum bitmap_page_attr attr)
762
{
763
	return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779
}

/*
 * 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);

780
	if (!bitmap->filemap) {
781 782 783 784
		return;
	}

	page = filemap_get_page(bitmap, chunk);
785
	if (!page) return;
786 787 788 789
	bit = file_page_offset(chunk);

 	/* set the bit */
	kaddr = kmap_atomic(page, KM_USER0);
790 791 792 793
	if (bitmap->flags & BITMAP_HOSTENDIAN)
		set_bit(bit, kaddr);
	else
		ext2_set_bit(bit, kaddr);
794 795 796 797 798 799 800 801 802 803 804
	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 */
805
void bitmap_unplug(struct bitmap *bitmap)
806
{
807 808
	unsigned long i, flags;
	int dirty, need_write;
809 810 811 812
	struct page *page;
	int wait = 0;

	if (!bitmap)
813
		return;
814 815 816 817 818

	/* 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);
819
		if (!bitmap->filemap) {
820
			spin_unlock_irqrestore(&bitmap->lock, flags);
821
			return;
822 823
		}
		page = bitmap->filemap[i];
824 825
		dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
		need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
826 827
		clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
		clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
828
		if (dirty)
829 830 831
			wait = 1;
		spin_unlock_irqrestore(&bitmap->lock, flags);

832
		if (dirty | need_write)
833
			write_page(bitmap, page, 0);
834 835
	}
	if (wait) { /* if any writes were performed, we need to wait on them */
836
		if (bitmap->file)
837 838
			wait_event(bitmap->write_wait,
				   atomic_read(&bitmap->pending_writes)==0);
839
		else
840
			md_super_wait(bitmap->mddev);
841
	}
842 843
	if (bitmap->flags & BITMAP_WRITE_ERROR)
		bitmap_file_kick(bitmap);
844 845
}

846
static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
847 848 849 850 851 852 853
/* * 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.
854 855 856
 *
 * We ignore all bits for sectors that end earlier than 'start'.
 * This is used when reading an out-of-date bitmap...
857
 */
858
static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
859 860 861 862 863
{
	unsigned long i, chunks, index, oldindex, bit;
	struct page *page = NULL, *oldpage = NULL;
	unsigned long num_pages, bit_cnt = 0;
	struct file *file;
864
	unsigned long bytes, offset;
865 866
	int outofdate;
	int ret = -ENOSPC;
867
	void *paddr;
868 869 870 871

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

872
	BUG_ON(!file && !bitmap->offset);
873

874
#ifdef INJECT_FAULTS_3
875 876 877 878 879 880 881 882 883
	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;
884

885
	num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE;
886

887
	if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
888 889 890 891
		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));
892
		goto err;
893
	}
894 895 896

	ret = -ENOMEM;

897
	bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
898
	if (!bitmap->filemap)
899
		goto err;
900

901 902
	/* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
	bitmap->filemap_attr = kzalloc(
903
		roundup( DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
904
		GFP_KERNEL);
905
	if (!bitmap->filemap_attr)
906
		goto err;
907 908 909 910

	oldindex = ~0L;

	for (i = 0; i < chunks; i++) {
911
		int b;
912 913 914
		index = file_page_index(i);
		bit = file_page_offset(i);
		if (index != oldindex) { /* this is a new page, read it in */
915
			int count;
916
			/* unmap the old page, we're done with it */
917
			if (index == num_pages-1)
918 919
				count = bytes + sizeof(bitmap_super_t)
					- index * PAGE_SIZE;
920 921
			else
				count = PAGE_SIZE;
922 923 924 925 926 927 928 929
			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);
930
			} else if (file) {
931
				page = read_page(file, index, bitmap, count);
932 933 934
				offset = 0;
			} else {
				page = read_sb_page(bitmap->mddev, bitmap->offset, index);
935 936
				offset = 0;
			}
937 938
			if (IS_ERR(page)) { /* read error */
				ret = PTR_ERR(page);
939
				goto err;
940 941
			}

942 943 944 945 946 947 948 949
			oldindex = index;
			oldpage = page;

			if (outofdate) {
				/*
				 * if bitmap is out of date, dirty the
			 	 * whole page and write it out
				 */
950 951
				paddr = kmap_atomic(page, KM_USER0);
				memset(paddr + offset, 0xff,
952
				       PAGE_SIZE - offset);
953
				kunmap_atomic(paddr, KM_USER0);
954 955 956 957
				write_page(bitmap, page, 1);

				ret = -EIO;
				if (bitmap->flags & BITMAP_WRITE_ERROR) {
958
					/* release, page not in filemap yet */
959
					put_page(page);
960
					goto err;
961 962 963 964
				}
			}

			bitmap->filemap[bitmap->file_pages++] = page;
965
			bitmap->last_page_size = count;
966
		}
967
		paddr = kmap_atomic(page, KM_USER0);
968
		if (bitmap->flags & BITMAP_HOSTENDIAN)
969
			b = test_bit(bit, paddr);
970
		else
971 972
			b = ext2_test_bit(bit, paddr);
		kunmap_atomic(paddr, KM_USER0);
973
		if (b) {
974
			/* if the disk bit is set, set the memory bit */
975 976 977
			bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap),
					       ((i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) >= start)
				);
978
			bit_cnt++;
979
			set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
980 981 982 983 984 985 986 987 988 989 990 991 992
		}
	}

 	/* 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: "
993 994 995 996
		"read %lu/%lu pages, set %lu bits\n",
		bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt);

	return 0;
997

998 999 1000
 err:
	printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
	       bmname(bitmap), ret);
1001 1002 1003
	return ret;
}

1004 1005 1006 1007 1008
void bitmap_write_all(struct bitmap *bitmap)
{
	/* We don't actually write all bitmap blocks here,
	 * just flag them as needing to be written
	 */
1009
	int i;
1010

1011 1012 1013
	for (i=0; i < bitmap->file_pages; i++)
		set_page_attr(bitmap, bitmap->filemap[i],
			      BITMAP_PAGE_NEEDWRITE);
1014 1015
}

1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036

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
 */

1037
void bitmap_daemon_work(struct bitmap *bitmap)
1038
{
1039
	unsigned long j;
1040 1041 1042
	unsigned long flags;
	struct page *page = NULL, *lastpage = NULL;
	int blocks;
1043
	void *paddr;
1044 1045

	if (bitmap == NULL)
1046
		return;
1047
	if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ))
1048
		return;
1049
	bitmap->daemon_lastrun = jiffies;
1050 1051 1052 1053 1054
	if (bitmap->allclean) {
		bitmap->mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
		return;
	}
	bitmap->allclean = 1;
1055 1056 1057 1058

	for (j = 0; j < bitmap->chunks; j++) {
		bitmap_counter_t *bmc;
		spin_lock_irqsave(&bitmap->lock, flags);
1059
		if (!bitmap->filemap) {
1060 1061 1062 1063 1064 1065 1066 1067
			/* error or shutdown */
			spin_unlock_irqrestore(&bitmap->lock, flags);
			break;
		}

		page = filemap_get_page(bitmap, j);

		if (page != lastpage) {
1068
			/* skip this page unless it's marked as needing cleaning */
1069 1070 1071
			if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
				int need_write = test_page_attr(bitmap, page,
								BITMAP_PAGE_NEEDWRITE);
1072
				if (need_write)
1073
					clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
1074

1075
				spin_unlock_irqrestore(&bitmap->lock, flags);
1076
				if (need_write) {
1077
					write_page(bitmap, page, 0);
1078 1079
					bitmap->allclean = 0;
				}
1080 1081 1082
				continue;
			}

1083 1084
			/* grab the new page, sync and release the old */
			if (lastpage != NULL) {
1085
				if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1086 1087
					clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
					spin_unlock_irqrestore(&bitmap->lock, flags);
1088
					write_page(bitmap, lastpage, 0);
1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107
				} else {
					set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
					spin_unlock_irqrestore(&bitmap->lock, flags);
				}
			} else
				spin_unlock_irqrestore(&bitmap->lock, flags);
			lastpage = page;
/*
			printk("bitmap clean at page %lu\n", j);
*/
			spin_lock_irqsave(&bitmap->lock, flags);
			clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
		}
		bmc = bitmap_get_counter(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
					&blocks, 0);
		if (bmc) {
/*
  if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc);
*/
1108 1109 1110
			if (*bmc)
				bitmap->allclean = 0;

1111 1112 1113 1114 1115 1116 1117 1118 1119 1120
			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;
				bitmap_count_page(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
						  -1);

				/* clear the bit */
1121
				paddr = kmap_atomic(page, KM_USER0);
1122
				if (bitmap->flags & BITMAP_HOSTENDIAN)
1123
					clear_bit(file_page_offset(j), paddr);
1124
				else
1125 1126
					ext2_clear_bit(file_page_offset(j), paddr);
				kunmap_atomic(paddr, KM_USER0);
1127 1128 1129 1130 1131 1132 1133 1134
			}
		}
		spin_unlock_irqrestore(&bitmap->lock, flags);
	}

	/* now sync the final page */
	if (lastpage != NULL) {
		spin_lock_irqsave(&bitmap->lock, flags);
1135
		if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
1136 1137
			clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
			spin_unlock_irqrestore(&bitmap->lock, flags);
1138
			write_page(bitmap, lastpage, 0);
1139 1140 1141 1142 1143 1144
		} else {
			set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
			spin_unlock_irqrestore(&bitmap->lock, flags);
		}
	}

1145 1146
	if (bitmap->allclean == 0)
		bitmap->mddev->thread->timeout = bitmap->daemon_sleep * HZ;
1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
}

static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
					    sector_t offset, int *blocks,
					    int create)
{
	/* 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]);
	}
}

1186
int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1187 1188
{
	if (!bitmap) return 0;
1189 1190 1191 1192 1193 1194 1195

	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);
	}

1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206
	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;
		}

1207 1208 1209 1210 1211 1212 1213 1214 1215
		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);
1216
			blk_unplug(bitmap->mddev->queue);
1217 1218 1219 1220 1221
			schedule();
			finish_wait(&bitmap->overflow_wait, &__wait);
			continue;
		}

1222 1223 1224 1225 1226 1227 1228 1229 1230
		switch(*bmc) {
		case 0:
			bitmap_file_set_bit(bitmap, offset);
			bitmap_count_page(bitmap,offset, 1);
			blk_plug_device(bitmap->mddev->queue);
			/* fall through */
		case 1:
			*bmc = 2;
		}
1231

1232 1233 1234 1235 1236 1237 1238 1239 1240
		(*bmc)++;

		spin_unlock_irq(&bitmap->lock);

		offset += blocks;
		if (sectors > blocks)
			sectors -= blocks;
		else sectors = 0;
	}
1241
	bitmap->allclean = 0;
1242 1243 1244 1245
	return 0;
}

void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1246
		     int success, int behind)
1247 1248
{
	if (!bitmap) return;
1249 1250 1251 1252 1253 1254
	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);
	}

1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269
	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;
		}

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

1270 1271 1272
		if ((*bmc & COUNTER_MAX) == COUNTER_MAX)
			wake_up(&bitmap->overflow_wait);

1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286
		(*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;
	}
}

1287 1288
int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks,
			int degraded)
1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304
{
	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;
1305 1306 1307 1308
			if (!degraded) { /* don't set/clear bits if degraded */
				*bmc |= RESYNC_MASK;
				*bmc &= ~NEEDED_MASK;
			}
1309 1310 1311
		}
	}
	spin_unlock_irq(&bitmap->lock);
1312
	bitmap->allclean = 0;
1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348
	return rv;
}

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);
1349
	bitmap->allclean = 0;
1350 1351 1352 1353 1354 1355 1356 1357 1358 1359
}

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
1360 1361
	if (!bitmap)
		return;
1362 1363
	while (sector < bitmap->mddev->resync_max_sectors) {
		bitmap_end_sync(bitmap, sector, &blocks, 0);
N
NeilBrown 已提交
1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389
		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
				  + bitmap->daemon_sleep * HZ)))
		return;
	wait_event(bitmap->mddev->recovery_wait,
		   atomic_read(&bitmap->mddev->recovery_active) == 0);

	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;
1390
	}
N
NeilBrown 已提交
1391
	bitmap->last_end_sync = jiffies;
1392 1393
}

1394
static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1395 1396
{
	/* For each chunk covered by any of these sectors, set the
1397
	 * counter to 1 and set resync_needed.  They should all
1398 1399
	 * be 0 at this point
	 */
1400 1401 1402 1403 1404 1405

	int secs;
	bitmap_counter_t *bmc;
	spin_lock_irq(&bitmap->lock);
	bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
	if (!bmc) {
1406
		spin_unlock_irq(&bitmap->lock);
1407
		return;
1408
	}
1409 1410
	if (! *bmc) {
		struct page *page;
1411
		*bmc = 1 | (needed?NEEDED_MASK:0);
1412 1413 1414 1415 1416
		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);
1417
	bitmap->allclean = 0;
1418 1419
}

1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431
/* 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++) {
		sector_t sec = chunk << CHUNK_BLOCK_SHIFT(bitmap);
		bitmap_set_memory_bits(bitmap, sec, 1);
		bitmap_file_set_bit(bitmap, sec);
	}
}

1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454
/*
 * flush out any pending updates
 */
void bitmap_flush(mddev_t *mddev)
{
	struct bitmap *bitmap = mddev->bitmap;
	int sleep;

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

	/* run the daemon_work three time to ensure everything is flushed
	 * that can be
	 */
	sleep = bitmap->daemon_sleep;
	bitmap->daemon_sleep = 0;
	bitmap_daemon_work(bitmap);
	bitmap_daemon_work(bitmap);
	bitmap_daemon_work(bitmap);
	bitmap->daemon_sleep = sleep;
	bitmap_update_sb(bitmap);
}

1455 1456 1457
/*
 * free memory that was allocated
 */
1458
static void bitmap_free(struct bitmap *bitmap)
1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480
{
	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);
}
1481 1482 1483 1484 1485 1486 1487 1488
void bitmap_destroy(mddev_t *mddev)
{
	struct bitmap *bitmap = mddev->bitmap;

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

	mddev->bitmap = NULL; /* disconnect from the md device */
1489 1490
	if (mddev->thread)
		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1491 1492 1493

	bitmap_free(bitmap);
}
1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506

/*
 * 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;
	unsigned long blocks = mddev->resync_max_sectors;
	unsigned long chunks;
	unsigned long pages;
	struct file *file = mddev->bitmap_file;
	int err;
1507
	sector_t start;
1508

A
Alexey Dobriyan 已提交
1509
	BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1510

1511
	if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */
1512 1513
		return 0;

1514 1515
	BUG_ON(file && mddev->bitmap_offset);

1516
	bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1517 1518 1519 1520
	if (!bitmap)
		return -ENOMEM;

	spin_lock_init(&bitmap->lock);
1521 1522
	atomic_set(&bitmap->pending_writes, 0);
	init_waitqueue_head(&bitmap->write_wait);
1523
	init_waitqueue_head(&bitmap->overflow_wait);
1524

1525 1526 1527
	bitmap->mddev = mddev;

	bitmap->file = file;
1528
	bitmap->offset = mddev->bitmap_offset;
1529 1530
	if (file) {
		get_file(file);
M
Mark Fasheh 已提交
1531 1532 1533 1534
		do_sync_mapping_range(file->f_mapping, 0, LLONG_MAX,
				      SYNC_FILE_RANGE_WAIT_BEFORE |
				      SYNC_FILE_RANGE_WRITE |
				      SYNC_FILE_RANGE_WAIT_AFTER);
1535
	}
1536 1537 1538
	/* read superblock from bitmap file (this sets bitmap->chunksize) */
	err = bitmap_read_sb(bitmap);
	if (err)
1539
		goto error;
1540

1541
	bitmap->chunkshift = ffz(~bitmap->chunksize);
1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556

	/* now that chunksize and chunkshift are set, we can use these macros */
 	chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) /
			CHUNK_BLOCK_RATIO(bitmap);
 	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;

1557
#ifdef INJECT_FATAL_FAULT_1
1558 1559
	bitmap->bp = NULL;
#else
1560
	bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1561
#endif
1562
	err = -ENOMEM;
1563
	if (!bitmap->bp)
1564
		goto error;
1565 1566 1567

	/* now that we have some pages available, initialize the in-memory
	 * bitmap from the on-disk bitmap */
1568 1569 1570 1571 1572 1573
	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);
1574

1575
	if (err)
1576
		goto error;
1577 1578 1579 1580

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

1581 1582
	mddev->bitmap = bitmap;

1583 1584
	mddev->thread->timeout = bitmap->daemon_sleep * HZ;

1585 1586 1587
	bitmap_update_sb(bitmap);

	return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
1588 1589 1590 1591

 error:
	bitmap_free(bitmap);
	return err;
1592 1593 1594 1595 1596 1597 1598 1599 1600
}

/* 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
1601
EXPORT_SYMBOL(bitmap_cond_end_sync);