bitmap.c 55.2 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).
 */

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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 <linux/seq_file.h>
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#include "md.h"
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#include "bitmap.h"
32

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

/*
 * 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
 */
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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;

	/* this page has not been allocated yet */

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	spin_unlock_irq(&bitmap->lock);
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	mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
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	spin_lock_irq(&bitmap->lock);

	if (mappage == NULL) {
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		pr_debug("%s: bitmap map page allocation failed, hijacking\n",
			 bmname(bitmap));
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		/* failed - set the hijacked flag so that we can use the
		 * pointer as a counter */
		if (!bitmap->bp[page].map)
			bitmap->bp[page].hijacked = 1;
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	} else if (bitmap->bp[page].map ||
		   bitmap->bp[page].hijacked) {
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		/* somebody beat us to getting the page */
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		kfree(mappage);
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		return 0;
90
	} else {
91

92
		/* no page was in place and we have one, so install it */
93

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		bitmap->bp[page].map = mappage;
		bitmap->missing_pages--;
	}
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	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;
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	} else {
		/* normal case, free the page */
		ptr = bitmap->bp[page].map;
		bitmap->bp[page].map = NULL;
		bitmap->missing_pages++;
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		kfree(ptr);
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	}
}

/*
 * 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 int read_sb_page(struct mddev *mddev, loff_t offset,
			struct page *page,
			unsigned long index, int size)
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{
	/* choose a good rdev and read the page from there */

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	struct md_rdev *rdev;
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	sector_t target;

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NeilBrown 已提交
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	rdev_for_each(rdev, 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 = offset + index * (PAGE_SIZE/512);
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		if (sync_page_io(rdev, target,
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				 roundup(size, bdev_logical_block_size(rdev->bdev)),
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				 page, READ, true)) {
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			page->index = index;
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			return 0;
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		}
	}
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	return -EIO;
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}

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static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
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{
	/* 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) {
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		rdev = list_entry(pos, struct md_rdev, same_set);
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		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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	struct md_rdev *rdev = NULL;
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	struct block_device *bdev;
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	struct mddev *mddev = bitmap->mddev;
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	struct bitmap_storage *store = &bitmap->storage;
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	while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
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		int size = PAGE_SIZE;
		loff_t offset = mddev->bitmap_info.offset;
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		bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;

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		if (page->index == store->file_pages-1) {
			int last_page_size = store->bytes & (PAGE_SIZE-1);
			if (last_page_size == 0)
				last_page_size = PAGE_SIZE;
			size = roundup(last_page_size,
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				       bdev_logical_block_size(bdev));
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		}
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		/* Just make sure we aren't corrupting data or
		 * metadata
		 */
		if (mddev->external) {
			/* Bitmap could be anywhere. */
			if (rdev->sb_start + offset + (page->index
						       * (PAGE_SIZE/512))
			    > rdev->data_offset
			    &&
			    rdev->sb_start + offset
			    < (rdev->data_offset + mddev->dev_sectors
			     + (PAGE_SIZE/512)))
				goto bad_alignment;
		} else if (offset < 0) {
			/* DATA  BITMAP METADATA  */
			if (offset
			    + (long)(page->index * (PAGE_SIZE/512))
			    + size/512 > 0)
				/* bitmap runs in to metadata */
				goto bad_alignment;
			if (rdev->data_offset + mddev->dev_sectors
			    > rdev->sb_start + offset)
				/* data runs in to bitmap */
				goto bad_alignment;
		} else if (rdev->sb_start < rdev->data_offset) {
			/* METADATA BITMAP DATA */
			if (rdev->sb_start
			    + offset
			    + page->index*(PAGE_SIZE/512) + size/512
			    > rdev->data_offset)
				/* bitmap runs in to data */
				goto bad_alignment;
		} else {
			/* DATA METADATA BITMAP - no problems */
		}
		md_super_write(mddev, rdev,
			       rdev->sb_start + offset
			       + page->index * (PAGE_SIZE/512),
			       size,
			       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->storage.file == NULL) {
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		switch (write_sb_page(bitmap, page, wait)) {
		case -EINVAL:
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			set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
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		}
276
	} 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);
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			submit_bh(WRITE | REQ_SYNC, bh);
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			bh = bh->b_this_page;
		}
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		if (wait)
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			wait_event(bitmap->write_wait,
				   atomic_read(&bitmap->pending_writes)==0);
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	}
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	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
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		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;
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	if (!uptodate)
		set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
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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)
{
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	struct buffer_head *bh;
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	if (!PagePrivate(page))
		return;

	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 int read_page(struct file *file, unsigned long index,
		     struct bitmap *bitmap,
		     unsigned long count,
		     struct page *page)
342
{
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	int ret = 0;
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	struct inode *inode = file->f_path.dentry->d_inode;
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	struct buffer_head *bh;
	sector_t block;
347

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	pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
		 (unsigned long long)index << PAGE_SHIFT);
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	bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
	if (!bh) {
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		ret = -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! */
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				ret = -EINVAL;
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				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);
388
	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
389
		ret = -EIO;
390
out:
391 392
	if (ret)
		printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %d\n",
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			(int)PAGE_SIZE,
			(unsigned long long)index << PAGE_SHIFT,
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			ret);
	return ret;
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}

/*
 * bitmap file superblock operations
 */

/* update the event counter and sync the superblock to disk */
404
void bitmap_update_sb(struct bitmap *bitmap)
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{
	bitmap_super_t *sb;

	if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
409
		return;
410 411
	if (bitmap->mddev->bitmap_info.external)
		return;
412
	if (!bitmap->storage.sb_page) /* no superblock */
413
		return;
414
	sb = kmap_atomic(bitmap->storage.sb_page);
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	sb->events = cpu_to_le64(bitmap->mddev->events);
416
	if (bitmap->mddev->events < bitmap->events_cleared)
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		/* rocking back to read-only */
		bitmap->events_cleared = bitmap->mddev->events;
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	sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
	sb->state = cpu_to_le32(bitmap->flags);
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	/* Just in case these have been changed via sysfs: */
	sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
	sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
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	kunmap_atomic(sb);
425
	write_page(bitmap, bitmap->storage.sb_page, 1);
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}

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

433
	if (!bitmap || !bitmap->storage.sb_page)
434
		return;
435
	sb = kmap_atomic(bitmap->storage.sb_page);
436
	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",
445
			(unsigned long long) le64_to_cpu(sb->events));
446
	printk(KERN_DEBUG "events cleared: %llu\n",
447
			(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);
453
	printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
454
	kunmap_atomic(sb);
455 456
}

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/*
 * bitmap_new_disk_sb
 * @bitmap
 *
 * This function is somewhat the reverse of bitmap_read_sb.  bitmap_read_sb
 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
 * This function verifies 'bitmap_info' and populates the on-disk bitmap
 * structure, which is to be written to disk.
 *
 * Returns: 0 on success, -Exxx on error
 */
static int bitmap_new_disk_sb(struct bitmap *bitmap)
{
	bitmap_super_t *sb;
	unsigned long chunksize, daemon_sleep, write_behind;
	int err = -EINVAL;

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	bitmap->storage.sb_page = alloc_page(GFP_KERNEL);
	if (IS_ERR(bitmap->storage.sb_page)) {
		err = PTR_ERR(bitmap->storage.sb_page);
		bitmap->storage.sb_page = NULL;
478 479
		return err;
	}
480
	bitmap->storage.sb_page->index = 0;
481

482
	sb = kmap_atomic(bitmap->storage.sb_page);
483 484 485 486 487 488 489

	sb->magic = cpu_to_le32(BITMAP_MAGIC);
	sb->version = cpu_to_le32(BITMAP_MAJOR_HI);

	chunksize = bitmap->mddev->bitmap_info.chunksize;
	BUG_ON(!chunksize);
	if (!is_power_of_2(chunksize)) {
490
		kunmap_atomic(sb);
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		printk(KERN_ERR "bitmap chunksize not a power of 2\n");
		return -EINVAL;
	}
	sb->chunksize = cpu_to_le32(chunksize);

	daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
	if (!daemon_sleep ||
	    (daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
		printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
		daemon_sleep = 5 * HZ;
	}
	sb->daemon_sleep = cpu_to_le32(daemon_sleep);
	bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;

	/*
	 * FIXME: write_behind for RAID1.  If not specified, what
	 * is a good choice?  We choose COUNTER_MAX / 2 arbitrarily.
	 */
	write_behind = bitmap->mddev->bitmap_info.max_write_behind;
	if (write_behind > COUNTER_MAX)
		write_behind = COUNTER_MAX / 2;
	sb->write_behind = cpu_to_le32(write_behind);
	bitmap->mddev->bitmap_info.max_write_behind = write_behind;

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

	memcpy(sb->uuid, bitmap->mddev->uuid, 16);

520
	set_bit(BITMAP_STALE, &bitmap->flags);
521
	sb->state = cpu_to_le32(bitmap->flags);
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	bitmap->events_cleared = bitmap->mddev->events;
	sb->events_cleared = cpu_to_le64(bitmap->mddev->events);

525
	kunmap_atomic(sb);
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	return 0;
}

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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;
535
	unsigned long chunksize, daemon_sleep, write_behind;
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	unsigned long long events;
	int err = -EINVAL;
538
	struct page *sb_page;
539

540
	if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
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		chunksize = 128 * 1024 * 1024;
		daemon_sleep = 5 * HZ;
		write_behind = 0;
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		set_bit(BITMAP_STALE, &bitmap->flags);
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		err = 0;
		goto out_no_sb;
	}
548
	/* page 0 is the superblock, read it... */
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	sb_page = alloc_page(GFP_KERNEL);
	if (!sb_page)
		return -ENOMEM;
552
	bitmap->storage.sb_page = sb_page;
553

554 555
	if (bitmap->storage.file) {
		loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
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		int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;

558
		err = read_page(bitmap->storage.file, 0,
559
				bitmap, bytes, sb_page);
560
	} else {
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		err = read_sb_page(bitmap->mddev,
				   bitmap->mddev->bitmap_info.offset,
				   sb_page,
				   0, sizeof(bitmap_super_t));
565
	}
566
	if (err)
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		return err;

569
	sb = kmap_atomic(sb_page);
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	chunksize = le32_to_cpu(sb->chunksize);
572
	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)
580
		reason = "unrecognized superblock version";
581
	else if (chunksize < 512)
582
		reason = "bitmap chunksize too small";
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Jonathan Brassow 已提交
583
	else if (!is_power_of_2(chunksize))
584
		reason = "bitmap chunksize not a power of 2";
585
	else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
586
		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);

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	if (bitmap->mddev->persistent) {
		/*
		 * We have a persistent array superblock, so 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);
616
			set_bit(BITMAP_STALE, &bitmap->flags);
617
		}
618
	}
619

620
	/* assign fields using values from superblock */
621
	bitmap->flags |= le32_to_cpu(sb->state);
622
	if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
623
		set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
624 625 626
	bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
	err = 0;
out:
627
	kunmap_atomic(sb);
628
out_no_sb:
629
	if (test_bit(BITMAP_STALE, &bitmap->flags))
630 631 632 633
		bitmap->events_cleared = bitmap->mddev->events;
	bitmap->mddev->bitmap_info.chunksize = chunksize;
	bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
	bitmap->mddev->bitmap_info.max_write_behind = write_behind;
634 635 636 637 638 639 640 641 642
	if (err)
		bitmap_print_sb(bitmap);
	return err;
}

/*
 * general bitmap file operations
 */

643 644 645 646 647 648
/*
 * on-disk bitmap:
 *
 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
 * file a page at a time. There's a superblock at the start of the file.
 */
649
/* calculate the index of the page that contains this bit */
650 651
static inline unsigned long file_page_index(struct bitmap_storage *store,
					    unsigned long chunk)
652
{
653
	if (store->sb_page)
654 655
		chunk += sizeof(bitmap_super_t) << 3;
	return chunk >> PAGE_BIT_SHIFT;
656 657 658
}

/* calculate the (bit) offset of this bit within a page */
659 660
static inline unsigned long file_page_offset(struct bitmap_storage *store,
					     unsigned long chunk)
661
{
662
	if (store->sb_page)
663 664
		chunk += sizeof(bitmap_super_t) << 3;
	return chunk & (PAGE_BITS - 1);
665 666 667 668 669 670 671 672 673
}

/*
 * 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
 */
674
static inline struct page *filemap_get_page(struct bitmap_storage *store,
675
					    unsigned long chunk)
676
{
677
	if (file_page_index(store, chunk) >= store->file_pages)
678
		return NULL;
679 680
	return store->filemap[file_page_index(store, chunk)
			      - file_page_index(store, 0)];
681 682
}

683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
static int bitmap_storage_alloc(struct bitmap_storage *store,
				unsigned long chunks, int with_super)
{
	int pnum;
	unsigned long num_pages;
	unsigned long bytes;

	bytes = DIV_ROUND_UP(chunks, 8);
	if (with_super)
		bytes += sizeof(bitmap_super_t);

	num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);

	store->filemap = kmalloc(sizeof(struct page *)
				 * num_pages, GFP_KERNEL);
	if (!store->filemap)
		return -ENOMEM;

	if (with_super && !store->sb_page) {
		store->sb_page = alloc_page(GFP_KERNEL);
		if (store->sb_page == NULL)
			return -ENOMEM;
		store->sb_page->index = 0;
	}
	pnum = 0;
	if (store->sb_page) {
		store->filemap[0] = store->sb_page;
		pnum = 1;
	}
	for ( ; pnum < num_pages; pnum++) {
		store->filemap[pnum] = alloc_page(GFP_KERNEL);
		if (!store->filemap[pnum]) {
			store->file_pages = pnum;
			return -ENOMEM;
		}
		store->filemap[pnum]->index = pnum;
	}
	store->file_pages = pnum;

	/* We need 4 bits per page, rounded up to a multiple
	 * of sizeof(unsigned long) */
	store->filemap_attr = kzalloc(
		roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
		GFP_KERNEL);
	if (!store->filemap_attr)
		return -ENOMEM;

	store->bytes = bytes;

	return 0;
}

735
static void bitmap_file_unmap(struct bitmap_storage *store)
736 737 738
{
	struct page **map, *sb_page;
	int pages;
739
	struct file *file;
740

741
	file = store->file;
742 743 744
	map = store->filemap;
	pages = store->file_pages;
	sb_page = store->sb_page;
745 746

	while (pages--)
747
		if (map[pages] != sb_page) /* 0 is sb_page, release it below */
748
			free_buffers(map[pages]);
749
	kfree(map);
750
	kfree(store->filemap_attr);
751

752 753
	if (sb_page)
		free_buffers(sb_page);
754

755
	if (file) {
J
Josef Sipek 已提交
756
		struct inode *inode = file->f_path.dentry->d_inode;
757
		invalidate_mapping_pages(inode->i_mapping, 0, -1);
758
		fput(file);
759
	}
760 761 762 763 764 765 766 767 768 769 770
}

/*
 * 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;

771
	if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
772
		bitmap_update_sb(bitmap);
773

774
		if (bitmap->storage.file) {
775 776
			path = kmalloc(PAGE_SIZE, GFP_KERNEL);
			if (path)
777 778
				ptr = d_path(&bitmap->storage.file->f_path,
					     path, PAGE_SIZE);
C
Christoph Hellwig 已提交
779

780 781
			printk(KERN_ALERT
			      "%s: kicking failed bitmap file %s from array!\n",
C
Christoph Hellwig 已提交
782
			      bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
783

784 785 786 787 788
			kfree(path);
		} else
			printk(KERN_ALERT
			       "%s: disabling internal bitmap due to errors\n",
			       bmname(bitmap));
789
	}
790 791 792
}

enum bitmap_page_attr {
793
	BITMAP_PAGE_DIRTY = 0,     /* there are set bits that need to be synced */
794 795
	BITMAP_PAGE_PENDING = 1,   /* there are bits that are being cleaned.
				    * i.e. counter is 1 or 2. */
796
	BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
797 798
};

799 800
static inline void set_page_attr(struct bitmap *bitmap, int pnum,
				 enum bitmap_page_attr attr)
801
{
802
	__set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
803 804
}

805 806
static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
				   enum bitmap_page_attr attr)
807
{
808
	__clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
809 810
}

811
static inline unsigned long test_page_attr(struct bitmap *bitmap, int pnum,
812
					   enum bitmap_page_attr attr)
813
{
814
	return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
815 816 817 818 819 820 821 822 823 824 825 826
}

/*
 * 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;
827
	struct page *page;
828
	void *kaddr;
829
	unsigned long chunk = block >> bitmap->chunkshift;
830

831
	page = filemap_get_page(&bitmap->storage, chunk);
832 833
	if (!page)
		return;
834
	bit = file_page_offset(&bitmap->storage, chunk);
835

836
	/* set the bit */
837
	kaddr = kmap_atomic(page);
838
	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
839 840 841
		set_bit(bit, kaddr);
	else
		__set_bit_le(bit, kaddr);
842
	kunmap_atomic(kaddr);
843
	pr_debug("set file bit %lu page %lu\n", bit, page->index);
844
	/* record page number so it gets flushed to disk when unplug occurs */
845
	set_page_attr(bitmap, page->index, BITMAP_PAGE_DIRTY);
846 847
}

848 849 850 851 852 853 854
static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
{
	unsigned long bit;
	struct page *page;
	void *paddr;
	unsigned long chunk = block >> bitmap->chunkshift;

855
	page = filemap_get_page(&bitmap->storage, chunk);
856 857
	if (!page)
		return;
858
	bit = file_page_offset(&bitmap->storage, chunk);
859
	paddr = kmap_atomic(page);
860
	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
861 862 863 864
		clear_bit(bit, paddr);
	else
		__clear_bit_le(bit, paddr);
	kunmap_atomic(paddr);
865 866
	if (!test_page_attr(bitmap, page->index, BITMAP_PAGE_NEEDWRITE)) {
		set_page_attr(bitmap, page->index, BITMAP_PAGE_PENDING);
867 868 869 870
		bitmap->allclean = 0;
	}
}

871 872 873
/* 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 */
874
void bitmap_unplug(struct bitmap *bitmap)
875
{
876
	unsigned long i;
877
	int dirty, need_write;
878 879
	int wait = 0;

880 881
	if (!bitmap || !bitmap->storage.filemap ||
	    test_bit(BITMAP_STALE, &bitmap->flags))
882
		return;
883 884 885

	/* look at each page to see if there are any set bits that need to be
	 * flushed out to disk */
886
	for (i = 0; i < bitmap->storage.file_pages; i++) {
887
		spin_lock_irq(&bitmap->lock);
888
		if (!bitmap->storage.filemap) {
889
			spin_unlock_irq(&bitmap->lock);
890
			return;
891
		}
892 893 894 895
		dirty = test_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
		need_write = test_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
		clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
		clear_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
896
		if (dirty || need_write)
897
			clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
898
		if (dirty)
899
			wait = 1;
900
		spin_unlock_irq(&bitmap->lock);
901

902
		if (dirty || need_write)
903
			write_page(bitmap, bitmap->storage.filemap[i], 0);
904 905
	}
	if (wait) { /* if any writes were performed, we need to wait on them */
906
		if (bitmap->storage.file)
907 908
			wait_event(bitmap->write_wait,
				   atomic_read(&bitmap->pending_writes)==0);
909
		else
910
			md_super_wait(bitmap->mddev);
911
	}
912
	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
913
		bitmap_file_kick(bitmap);
914
}
915
EXPORT_SYMBOL(bitmap_unplug);
916

917
static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
918 919 920 921 922 923 924
/* * 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.
925 926 927
 *
 * We ignore all bits for sectors that end earlier than 'start'.
 * This is used when reading an out-of-date bitmap...
928
 */
929
static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
930 931
{
	unsigned long i, chunks, index, oldindex, bit;
932
	struct page *page = NULL;
933
	unsigned long bit_cnt = 0;
934
	struct file *file;
935
	unsigned long offset;
936 937
	int outofdate;
	int ret = -ENOSPC;
938
	void *paddr;
939
	struct bitmap_storage *store = &bitmap->storage;
940 941

	chunks = bitmap->chunks;
942
	file = store->file;
943

944 945
	if (!file && !bitmap->mddev->bitmap_info.offset) {
		/* No permanent bitmap - fill with '1s'. */
946 947
		store->filemap = NULL;
		store->file_pages = 0;
948 949 950 951 952 953 954 955 956 957
		for (i = 0; i < chunks ; i++) {
			/* if the disk bit is set, set the memory bit */
			int needed = ((sector_t)(i+1) << (bitmap->chunkshift)
				      >= start);
			bitmap_set_memory_bits(bitmap,
					       (sector_t)i << bitmap->chunkshift,
					       needed);
		}
		return 0;
	}
958

959
	outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
960 961 962 963
	if (outofdate)
		printk(KERN_INFO "%s: bitmap file is out of date, doing full "
			"recovery\n", bmname(bitmap));

964
	if (file && i_size_read(file->f_mapping->host) < store->bytes) {
965
		printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
966 967 968
		       bmname(bitmap),
		       (unsigned long) i_size_read(file->f_mapping->host),
		       store->bytes);
969
		goto err;
970
	}
971

972
	oldindex = ~0L;
973
	offset = 0;
974
	if (!bitmap->mddev->bitmap_info.external)
975
		offset = sizeof(bitmap_super_t);
976 977

	for (i = 0; i < chunks; i++) {
978
		int b;
979 980
		index = file_page_index(&bitmap->storage, i);
		bit = file_page_offset(&bitmap->storage, i);
981
		if (index != oldindex) { /* this is a new page, read it in */
982
			int count;
983
			/* unmap the old page, we're done with it */
984 985
			if (index == store->file_pages-1)
				count = store->bytes - index * PAGE_SIZE;
986 987
			else
				count = PAGE_SIZE;
988
			page = store->filemap[index];
989 990 991 992 993 994 995 996 997 998 999
			if (file)
				ret = read_page(file, index, bitmap,
						count, page);
			else
				ret = read_sb_page(
					bitmap->mddev,
					bitmap->mddev->bitmap_info.offset,
					page,
					index, count);

			if (ret)
1000
				goto err;
1001

1002 1003 1004 1005 1006
			oldindex = index;

			if (outofdate) {
				/*
				 * if bitmap is out of date, dirty the
1007
				 * whole page and write it out
1008
				 */
1009
				paddr = kmap_atomic(page);
1010
				memset(paddr + offset, 0xff,
1011
				       PAGE_SIZE - offset);
1012
				kunmap_atomic(paddr);
1013 1014 1015
				write_page(bitmap, page, 1);

				ret = -EIO;
1016 1017
				if (test_bit(BITMAP_WRITE_ERROR,
					     &bitmap->flags))
1018
					goto err;
1019 1020
			}
		}
1021
		paddr = kmap_atomic(page);
1022
		if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
1023
			b = test_bit(bit, paddr);
1024
		else
A
Akinobu Mita 已提交
1025
			b = test_bit_le(bit, paddr);
1026
		kunmap_atomic(paddr);
1027
		if (b) {
1028
			/* if the disk bit is set, set the memory bit */
1029
			int needed = ((sector_t)(i+1) << bitmap->chunkshift
1030 1031
				      >= start);
			bitmap_set_memory_bits(bitmap,
1032
					       (sector_t)i << bitmap->chunkshift,
1033
					       needed);
1034 1035
			bit_cnt++;
		}
1036
		offset = 0;
1037 1038 1039
	}

	printk(KERN_INFO "%s: bitmap initialized from disk: "
1040
	       "read %lu pages, set %lu of %lu bits\n",
1041
	       bmname(bitmap), store->file_pages,
1042
	       bit_cnt, chunks);
1043 1044

	return 0;
1045

1046 1047 1048
 err:
	printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
	       bmname(bitmap), ret);
1049 1050 1051
	return ret;
}

1052 1053 1054 1055 1056
void bitmap_write_all(struct bitmap *bitmap)
{
	/* We don't actually write all bitmap blocks here,
	 * just flag them as needing to be written
	 */
1057
	int i;
1058

1059
	if (!bitmap || !bitmap->storage.filemap)
1060
		return;
1061
	if (bitmap->storage.file)
1062 1063 1064
		/* Only one copy, so nothing needed */
		return;

1065
	spin_lock_irq(&bitmap->lock);
1066
	for (i = 0; i < bitmap->storage.file_pages; i++)
1067
		set_page_attr(bitmap, i,
1068
			      BITMAP_PAGE_NEEDWRITE);
1069
	bitmap->allclean = 0;
1070
	spin_unlock_irq(&bitmap->lock);
1071 1072
}

1073 1074
static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
{
1075
	sector_t chunk = offset >> bitmap->chunkshift;
1076 1077 1078 1079
	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
	bitmap->bp[page].count += inc;
	bitmap_checkfree(bitmap, page);
}
1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090

static void bitmap_set_pending(struct bitmap *bitmap, sector_t offset)
{
	sector_t chunk = offset >> bitmap->chunkshift;
	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
	struct bitmap_page *bp = &bitmap->bp[page];

	if (!bp->pending)
		bp->pending = 1;
}

1091
static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
N
NeilBrown 已提交
1092
					    sector_t offset, sector_t *blocks,
1093 1094 1095 1096 1097 1098 1099
					    int create);

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

1100
void bitmap_daemon_work(struct mddev *mddev)
1101
{
1102
	struct bitmap *bitmap;
1103
	unsigned long j;
1104
	unsigned long nextpage;
N
NeilBrown 已提交
1105
	sector_t blocks;
1106

1107 1108 1109
	/* Use a mutex to guard daemon_work against
	 * bitmap_destroy.
	 */
1110
	mutex_lock(&mddev->bitmap_info.mutex);
1111 1112
	bitmap = mddev->bitmap;
	if (bitmap == NULL) {
1113
		mutex_unlock(&mddev->bitmap_info.mutex);
1114
		return;
1115
	}
1116
	if (time_before(jiffies, bitmap->daemon_lastrun
N
NeilBrown 已提交
1117
			+ mddev->bitmap_info.daemon_sleep))
1118 1119
		goto done;

1120
	bitmap->daemon_lastrun = jiffies;
1121
	if (bitmap->allclean) {
N
NeilBrown 已提交
1122
		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1123
		goto done;
1124 1125
	}
	bitmap->allclean = 1;
1126

1127 1128 1129 1130
	/* Any file-page which is PENDING now needs to be written.
	 * So set NEEDWRITE now, then after we make any last-minute changes
	 * we will write it.
	 */
1131
	spin_lock_irq(&bitmap->lock);
1132
	for (j = 0; j < bitmap->storage.file_pages; j++)
1133
		if (test_page_attr(bitmap, j,
1134
				   BITMAP_PAGE_PENDING)) {
1135
			set_page_attr(bitmap, j,
1136
				      BITMAP_PAGE_NEEDWRITE);
1137
			clear_page_attr(bitmap, j,
1138 1139 1140 1141 1142 1143 1144 1145 1146
					BITMAP_PAGE_PENDING);
		}

	if (bitmap->need_sync &&
	    mddev->bitmap_info.external == 0) {
		/* Arrange for superblock update as well as
		 * other changes */
		bitmap_super_t *sb;
		bitmap->need_sync = 0;
1147 1148
		if (bitmap->storage.filemap) {
			sb = kmap_atomic(bitmap->storage.sb_page);
1149 1150 1151
			sb->events_cleared =
				cpu_to_le64(bitmap->events_cleared);
			kunmap_atomic(sb);
1152
			set_page_attr(bitmap, 0,
1153 1154
				      BITMAP_PAGE_NEEDWRITE);
		}
1155 1156 1157 1158 1159
	}
	/* Now look at the bitmap counters and if any are '2' or '1',
	 * decrement and handle accordingly.
	 */
	nextpage = 0;
1160 1161
	for (j = 0; j < bitmap->chunks; j++) {
		bitmap_counter_t *bmc;
1162
		sector_t  block = (sector_t)j << bitmap->chunkshift;
1163

1164 1165 1166 1167
		if (j == nextpage) {
			nextpage += PAGE_COUNTER_RATIO;
			if (!bitmap->bp[j >> PAGE_COUNTER_SHIFT].pending) {
				j |= PAGE_COUNTER_MASK;
1168 1169
				continue;
			}
1170
			bitmap->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1171
		}
1172
		bmc = bitmap_get_counter(bitmap,
1173
					 block,
1174
					 &blocks, 0);
1175 1176

		if (!bmc) {
1177
			j |= PAGE_COUNTER_MASK;
1178 1179 1180 1181 1182
			continue;
		}
		if (*bmc == 1 && !bitmap->need_sync) {
			/* We can clear the bit */
			*bmc = 0;
1183 1184
			bitmap_count_page(bitmap, block, -1);
			bitmap_file_clear_bit(bitmap, block);
1185 1186
		} else if (*bmc && *bmc <= 2) {
			*bmc = 1;
1187
			bitmap_set_pending(bitmap, block);
1188
			bitmap->allclean = 0;
1189
		}
1190 1191
	}

1192 1193 1194 1195 1196 1197 1198 1199
	/* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
	 * DIRTY pages need to be written by bitmap_unplug so it can wait
	 * for them.
	 * If we find any DIRTY page we stop there and let bitmap_unplug
	 * handle all the rest.  This is important in the case where
	 * the first blocking holds the superblock and it has been updated.
	 * We mustn't write any other blocks before the superblock.
	 */
1200 1201 1202 1203
	for (j = 0;
	     j < bitmap->storage.file_pages
		     && !test_bit(BITMAP_STALE, &bitmap->flags);
	     j++) {
1204

1205
		if (test_page_attr(bitmap, j,
1206 1207 1208
				   BITMAP_PAGE_DIRTY))
			/* bitmap_unplug will handle the rest */
			break;
1209
		if (test_page_attr(bitmap, j,
1210
				   BITMAP_PAGE_NEEDWRITE)) {
1211
			clear_page_attr(bitmap, j,
1212
					BITMAP_PAGE_NEEDWRITE);
1213
			spin_unlock_irq(&bitmap->lock);
1214
			write_page(bitmap, bitmap->storage.filemap[j], 0);
1215
			spin_lock_irq(&bitmap->lock);
1216 1217
		}
	}
1218
	spin_unlock_irq(&bitmap->lock);
1219

1220
 done:
1221
	if (bitmap->allclean == 0)
N
NeilBrown 已提交
1222 1223
		mddev->thread->timeout =
			mddev->bitmap_info.daemon_sleep;
1224
	mutex_unlock(&mddev->bitmap_info.mutex);
1225 1226 1227
}

static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
N
NeilBrown 已提交
1228
					    sector_t offset, sector_t *blocks,
1229
					    int create)
1230 1231
__releases(bitmap->lock)
__acquires(bitmap->lock)
1232 1233 1234 1235 1236
{
	/* 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.
	 */
1237
	sector_t chunk = offset >> bitmap->chunkshift;
1238 1239 1240
	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
	unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
	sector_t csize;
1241
	int err;
1242

1243 1244 1245 1246
	err = bitmap_checkpage(bitmap, page, create);

	if (bitmap->bp[page].hijacked ||
	    bitmap->bp[page].map == NULL)
1247
		csize = ((sector_t)1) << (bitmap->chunkshift +
1248 1249
					  PAGE_COUNTER_SHIFT - 1);
	else
1250
		csize = ((sector_t)1) << bitmap->chunkshift;
1251 1252 1253
	*blocks = csize - (offset & (csize - 1));

	if (err < 0)
1254
		return NULL;
1255

1256 1257 1258 1259 1260 1261 1262 1263
	/* 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);
		return  &((bitmap_counter_t *)
			  &bitmap->bp[page].map)[hi];
1264
	} else /* page is allocated */
1265 1266 1267 1268
		return (bitmap_counter_t *)
			&(bitmap->bp[page].map[pageoff]);
}

1269
int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1270
{
1271 1272
	if (!bitmap)
		return 0;
1273 1274

	if (behind) {
1275
		int bw;
1276
		atomic_inc(&bitmap->behind_writes);
1277 1278 1279 1280
		bw = atomic_read(&bitmap->behind_writes);
		if (bw > bitmap->behind_writes_used)
			bitmap->behind_writes_used = bw;

1281 1282
		pr_debug("inc write-behind count %d/%lu\n",
			 bw, bitmap->mddev->bitmap_info.max_write_behind);
1283 1284
	}

1285
	while (sectors) {
N
NeilBrown 已提交
1286
		sector_t blocks;
1287 1288 1289 1290 1291 1292 1293 1294 1295
		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;
		}

1296
		if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1297 1298 1299 1300 1301 1302 1303 1304
			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);
J
Jens Axboe 已提交
1305
			io_schedule();
1306 1307 1308 1309
			finish_wait(&bitmap->overflow_wait, &__wait);
			continue;
		}

1310
		switch (*bmc) {
1311 1312
		case 0:
			bitmap_file_set_bit(bitmap, offset);
1313
			bitmap_count_page(bitmap, offset, 1);
1314 1315 1316 1317
			/* fall through */
		case 1:
			*bmc = 2;
		}
1318

1319 1320 1321 1322 1323 1324 1325
		(*bmc)++;

		spin_unlock_irq(&bitmap->lock);

		offset += blocks;
		if (sectors > blocks)
			sectors -= blocks;
1326 1327
		else
			sectors = 0;
1328 1329 1330
	}
	return 0;
}
1331
EXPORT_SYMBOL(bitmap_startwrite);
1332 1333

void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1334
		     int success, int behind)
1335
{
1336 1337
	if (!bitmap)
		return;
1338
	if (behind) {
1339 1340
		if (atomic_dec_and_test(&bitmap->behind_writes))
			wake_up(&bitmap->behind_wait);
1341 1342 1343
		pr_debug("dec write-behind count %d/%lu\n",
			 atomic_read(&bitmap->behind_writes),
			 bitmap->mddev->bitmap_info.max_write_behind);
1344 1345
	}

1346
	while (sectors) {
N
NeilBrown 已提交
1347
		sector_t blocks;
1348 1349 1350 1351 1352 1353 1354 1355 1356 1357
		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;
		}

1358
		if (success && !bitmap->mddev->degraded &&
1359 1360 1361
		    bitmap->events_cleared < bitmap->mddev->events) {
			bitmap->events_cleared = bitmap->mddev->events;
			bitmap->need_sync = 1;
1362
			sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1363 1364
		}

1365
		if (!success && !NEEDED(*bmc))
1366 1367
			*bmc |= NEEDED_MASK;

1368
		if (COUNTER(*bmc) == COUNTER_MAX)
1369 1370
			wake_up(&bitmap->overflow_wait);

1371
		(*bmc)--;
1372
		if (*bmc <= 2) {
1373
			bitmap_set_pending(bitmap, offset);
1374 1375
			bitmap->allclean = 0;
		}
1376 1377 1378 1379
		spin_unlock_irqrestore(&bitmap->lock, flags);
		offset += blocks;
		if (sectors > blocks)
			sectors -= blocks;
1380 1381
		else
			sectors = 0;
1382 1383
	}
}
1384
EXPORT_SYMBOL(bitmap_endwrite);
1385

N
NeilBrown 已提交
1386
static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1387
			       int degraded)
1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403
{
	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;
1404 1405 1406 1407
			if (!degraded) { /* don't set/clear bits if degraded */
				*bmc |= RESYNC_MASK;
				*bmc &= ~NEEDED_MASK;
			}
1408 1409 1410 1411 1412 1413
		}
	}
	spin_unlock_irq(&bitmap->lock);
	return rv;
}

N
NeilBrown 已提交
1414
int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1415 1416 1417 1418 1419 1420 1421 1422 1423 1424
		      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;
N
NeilBrown 已提交
1425
	sector_t blocks1;
1426 1427 1428 1429 1430 1431 1432 1433 1434 1435

	*blocks = 0;
	while (*blocks < (PAGE_SIZE>>9)) {
		rv |= __bitmap_start_sync(bitmap, offset,
					  &blocks1, degraded);
		offset += blocks1;
		*blocks += blocks1;
	}
	return rv;
}
1436
EXPORT_SYMBOL(bitmap_start_sync);
1437

N
NeilBrown 已提交
1438
void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1439 1440 1441
{
	bitmap_counter_t *bmc;
	unsigned long flags;
1442 1443

	if (bitmap == NULL) {
1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457
		*blocks = 1024;
		return;
	}
	spin_lock_irqsave(&bitmap->lock, flags);
	bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
	if (bmc == NULL)
		goto unlock;
	/* locked */
	if (RESYNC(*bmc)) {
		*bmc &= ~RESYNC_MASK;

		if (!NEEDED(*bmc) && aborted)
			*bmc |= NEEDED_MASK;
		else {
1458
			if (*bmc <= 2) {
1459
				bitmap_set_pending(bitmap, offset);
1460 1461
				bitmap->allclean = 0;
			}
1462 1463 1464 1465 1466
		}
	}
 unlock:
	spin_unlock_irqrestore(&bitmap->lock, flags);
}
1467
EXPORT_SYMBOL(bitmap_end_sync);
1468 1469 1470 1471 1472 1473 1474 1475

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;
N
NeilBrown 已提交
1476
	sector_t blocks;
N
NeilBrown 已提交
1477 1478
	if (!bitmap)
		return;
1479 1480
	while (sector < bitmap->mddev->resync_max_sectors) {
		bitmap_end_sync(bitmap, sector, &blocks, 0);
N
NeilBrown 已提交
1481 1482 1483
		sector += blocks;
	}
}
1484
EXPORT_SYMBOL(bitmap_close_sync);
N
NeilBrown 已提交
1485 1486 1487 1488

void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
{
	sector_t s = 0;
N
NeilBrown 已提交
1489
	sector_t blocks;
N
NeilBrown 已提交
1490 1491 1492 1493 1494 1495 1496 1497

	if (!bitmap)
		return;
	if (sector == 0) {
		bitmap->last_end_sync = jiffies;
		return;
	}
	if (time_before(jiffies, (bitmap->last_end_sync
1498
				  + bitmap->mddev->bitmap_info.daemon_sleep)))
N
NeilBrown 已提交
1499 1500 1501 1502
		return;
	wait_event(bitmap->mddev->recovery_wait,
		   atomic_read(&bitmap->mddev->recovery_active) == 0);

1503
	bitmap->mddev->curr_resync_completed = sector;
1504
	set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1505
	sector &= ~((1ULL << bitmap->chunkshift) - 1);
N
NeilBrown 已提交
1506 1507 1508 1509
	s = 0;
	while (s < sector && s < bitmap->mddev->resync_max_sectors) {
		bitmap_end_sync(bitmap, s, &blocks, 0);
		s += blocks;
1510
	}
N
NeilBrown 已提交
1511
	bitmap->last_end_sync = jiffies;
1512
	sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1513
}
1514
EXPORT_SYMBOL(bitmap_cond_end_sync);
1515

1516
static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1517 1518
{
	/* For each chunk covered by any of these sectors, set the
1519
	 * counter to 2 and possibly set resync_needed.  They should all
1520 1521
	 * be 0 at this point
	 */
1522

N
NeilBrown 已提交
1523
	sector_t secs;
1524 1525 1526 1527
	bitmap_counter_t *bmc;
	spin_lock_irq(&bitmap->lock);
	bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
	if (!bmc) {
1528
		spin_unlock_irq(&bitmap->lock);
1529
		return;
1530
	}
1531
	if (!*bmc) {
1532
		*bmc = 2 | (needed ? NEEDED_MASK : 0);
1533
		bitmap_count_page(bitmap, offset, 1);
1534
		bitmap_set_pending(bitmap, offset);
1535
		bitmap->allclean = 0;
1536 1537
	}
	spin_unlock_irq(&bitmap->lock);
1538 1539
}

1540 1541 1542 1543 1544 1545
/* 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++) {
1546
		sector_t sec = (sector_t)chunk << bitmap->chunkshift;
1547
		bitmap_set_memory_bits(bitmap, sec, 1);
1548
		spin_lock_irq(&bitmap->lock);
1549
		bitmap_file_set_bit(bitmap, sec);
1550
		spin_unlock_irq(&bitmap->lock);
1551 1552 1553 1554 1555 1556
		if (sec < bitmap->mddev->recovery_cp)
			/* We are asserting that the array is dirty,
			 * so move the recovery_cp address back so
			 * that it is obvious that it is dirty
			 */
			bitmap->mddev->recovery_cp = sec;
1557 1558 1559
	}
}

1560 1561 1562
/*
 * flush out any pending updates
 */
1563
void bitmap_flush(struct mddev *mddev)
1564 1565
{
	struct bitmap *bitmap = mddev->bitmap;
1566
	long sleep;
1567 1568 1569 1570 1571 1572 1573

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

	/* run the daemon_work three time to ensure everything is flushed
	 * that can be
	 */
1574
	sleep = mddev->bitmap_info.daemon_sleep * 2;
1575
	bitmap->daemon_lastrun -= sleep;
1576
	bitmap_daemon_work(mddev);
1577
	bitmap->daemon_lastrun -= sleep;
1578
	bitmap_daemon_work(mddev);
1579
	bitmap->daemon_lastrun -= sleep;
1580
	bitmap_daemon_work(mddev);
1581 1582 1583
	bitmap_update_sb(bitmap);
}

1584 1585 1586
/*
 * free memory that was allocated
 */
1587
static void bitmap_free(struct bitmap *bitmap)
1588 1589 1590 1591 1592 1593 1594
{
	unsigned long k, pages;
	struct bitmap_page *bp;

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

1595 1596 1597 1598 1599 1600
	/* Shouldn't be needed - but just in case.... */
	wait_event(bitmap->write_wait,
		   atomic_read(&bitmap->pending_writes) == 0);

	/* release the bitmap file  */
	bitmap_file_unmap(&bitmap->storage);
1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613

	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);
}
1614

1615
void bitmap_destroy(struct mddev *mddev)
1616 1617 1618 1619 1620 1621
{
	struct bitmap *bitmap = mddev->bitmap;

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

1622
	mutex_lock(&mddev->bitmap_info.mutex);
1623
	mddev->bitmap = NULL; /* disconnect from the md device */
1624
	mutex_unlock(&mddev->bitmap_info.mutex);
1625 1626
	if (mddev->thread)
		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1627

1628 1629 1630
	if (bitmap->sysfs_can_clear)
		sysfs_put(bitmap->sysfs_can_clear);

1631 1632
	bitmap_free(bitmap);
}
1633 1634 1635 1636 1637

/*
 * initialize the bitmap structure
 * if this returns an error, bitmap_destroy must be called to do clean up
 */
1638
int bitmap_create(struct mddev *mddev)
1639 1640
{
	struct bitmap *bitmap;
1641
	sector_t blocks = mddev->resync_max_sectors;
1642 1643
	unsigned long chunks;
	unsigned long pages;
1644
	struct file *file = mddev->bitmap_info.file;
1645
	int err;
1646
	struct sysfs_dirent *bm = NULL;
1647

A
Alexey Dobriyan 已提交
1648
	BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1649

1650
	BUG_ON(file && mddev->bitmap_info.offset);
1651

1652
	bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1653 1654 1655 1656
	if (!bitmap)
		return -ENOMEM;

	spin_lock_init(&bitmap->lock);
1657 1658
	atomic_set(&bitmap->pending_writes, 0);
	init_waitqueue_head(&bitmap->write_wait);
1659
	init_waitqueue_head(&bitmap->overflow_wait);
1660
	init_waitqueue_head(&bitmap->behind_wait);
1661

1662 1663
	bitmap->mddev = mddev;

1664 1665
	if (mddev->kobj.sd)
		bm = sysfs_get_dirent(mddev->kobj.sd, NULL, "bitmap");
1666
	if (bm) {
1667
		bitmap->sysfs_can_clear = sysfs_get_dirent(bm, NULL, "can_clear");
1668 1669 1670 1671
		sysfs_put(bm);
	} else
		bitmap->sysfs_can_clear = NULL;

1672
	bitmap->storage.file = file;
1673 1674
	if (file) {
		get_file(file);
1675 1676 1677 1678
		/* As future accesses to this file will use bmap,
		 * and bypass the page cache, we must sync the file
		 * first.
		 */
1679
		vfs_fsync(file, 1);
1680
	}
1681
	/* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1682 1683 1684 1685 1686 1687 1688 1689 1690 1691
	if (!mddev->bitmap_info.external) {
		/*
		 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
		 * instructing us to create a new on-disk bitmap instance.
		 */
		if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
			err = bitmap_new_disk_sb(bitmap);
		else
			err = bitmap_read_sb(bitmap);
	} else {
1692 1693 1694 1695 1696 1697 1698
		err = 0;
		if (mddev->bitmap_info.chunksize == 0 ||
		    mddev->bitmap_info.daemon_sleep == 0)
			/* chunksize and time_base need to be
			 * set first. */
			err = -EINVAL;
	}
1699
	if (err)
1700
		goto error;
1701

1702
	bitmap->daemon_lastrun = jiffies;
1703 1704
	bitmap->chunkshift = (ffz(~mddev->bitmap_info.chunksize)
			      - BITMAP_BLOCK_SHIFT);
1705

1706
	chunks = (blocks + (1 << bitmap->chunkshift) - 1) >>
1707
			bitmap->chunkshift;
1708
	pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1709 1710 1711 1712 1713 1714 1715

	BUG_ON(!pages);

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

1716
	bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1717

1718
	err = -ENOMEM;
1719
	if (!bitmap->bp)
1720
		goto error;
1721

1722 1723 1724 1725 1726 1727
	if (file || mddev->bitmap_info.offset) {
		err = bitmap_storage_alloc(&bitmap->storage, bitmap->chunks,
					   !mddev->bitmap_info.external);
		if (err)
			goto error;
	}
1728 1729 1730 1731 1732 1733
	printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
		pages, bmname(bitmap));

	mddev->bitmap = bitmap;


1734
	return test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1735 1736 1737 1738 1739 1740

 error:
	bitmap_free(bitmap);
	return err;
}

1741
int bitmap_load(struct mddev *mddev)
1742 1743
{
	int err = 0;
1744
	sector_t start = 0;
1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756
	sector_t sector = 0;
	struct bitmap *bitmap = mddev->bitmap;

	if (!bitmap)
		goto out;

	/* Clear out old bitmap info first:  Either there is none, or we
	 * are resuming after someone else has possibly changed things,
	 * so we should forget old cached info.
	 * All chunks should be clean, but some might need_sync.
	 */
	while (sector < mddev->resync_max_sectors) {
N
NeilBrown 已提交
1757
		sector_t blocks;
1758 1759 1760 1761 1762
		bitmap_start_sync(bitmap, sector, &blocks, 0);
		sector += blocks;
	}
	bitmap_close_sync(bitmap);

1763 1764 1765 1766 1767 1768
	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;

1769
	mutex_lock(&mddev->bitmap_info.mutex);
1770
	err = bitmap_init_from_disk(bitmap, start);
1771
	mutex_unlock(&mddev->bitmap_info.mutex);
1772

1773
	if (err)
1774
		goto out;
1775
	clear_bit(BITMAP_STALE, &bitmap->flags);
1776 1777 1778

	/* Kick recovery in case any bits were set */
	set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1779

1780
	mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1781
	md_wakeup_thread(mddev->thread);
1782

1783 1784
	bitmap_update_sb(bitmap);

1785
	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1786 1787
		err = -EIO;
out:
1788
	return err;
1789
}
1790
EXPORT_SYMBOL_GPL(bitmap_load);
1791

1792 1793 1794 1795 1796 1797 1798
void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
{
	unsigned long chunk_kb;

	if (!bitmap)
		return;

1799
	spin_lock_irq(&bitmap->lock);
1800 1801 1802 1803 1804 1805 1806 1807 1808
	chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
	seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
		   "%lu%s chunk",
		   bitmap->pages - bitmap->missing_pages,
		   bitmap->pages,
		   (bitmap->pages - bitmap->missing_pages)
		   << (PAGE_SHIFT - 10),
		   chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
		   chunk_kb ? "KB" : "B");
1809
	if (bitmap->storage.file) {
1810
		seq_printf(seq, ", file: ");
1811
		seq_path(seq, &bitmap->storage.file->f_path, " \t\n");
1812 1813 1814
	}

	seq_printf(seq, "\n");
1815
	spin_unlock_irq(&bitmap->lock);
1816 1817
}

1818
static ssize_t
1819
location_show(struct mddev *mddev, char *page)
1820 1821
{
	ssize_t len;
1822
	if (mddev->bitmap_info.file)
1823
		len = sprintf(page, "file");
1824
	else if (mddev->bitmap_info.offset)
1825
		len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
1826
	else
1827 1828 1829 1830 1831 1832
		len = sprintf(page, "none");
	len += sprintf(page+len, "\n");
	return len;
}

static ssize_t
1833
location_store(struct mddev *mddev, const char *buf, size_t len)
1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877
{

	if (mddev->pers) {
		if (!mddev->pers->quiesce)
			return -EBUSY;
		if (mddev->recovery || mddev->sync_thread)
			return -EBUSY;
	}

	if (mddev->bitmap || mddev->bitmap_info.file ||
	    mddev->bitmap_info.offset) {
		/* bitmap already configured.  Only option is to clear it */
		if (strncmp(buf, "none", 4) != 0)
			return -EBUSY;
		if (mddev->pers) {
			mddev->pers->quiesce(mddev, 1);
			bitmap_destroy(mddev);
			mddev->pers->quiesce(mddev, 0);
		}
		mddev->bitmap_info.offset = 0;
		if (mddev->bitmap_info.file) {
			struct file *f = mddev->bitmap_info.file;
			mddev->bitmap_info.file = NULL;
			restore_bitmap_write_access(f);
			fput(f);
		}
	} else {
		/* No bitmap, OK to set a location */
		long long offset;
		if (strncmp(buf, "none", 4) == 0)
			/* nothing to be done */;
		else if (strncmp(buf, "file:", 5) == 0) {
			/* Not supported yet */
			return -EINVAL;
		} else {
			int rv;
			if (buf[0] == '+')
				rv = strict_strtoll(buf+1, 10, &offset);
			else
				rv = strict_strtoll(buf, 10, &offset);
			if (rv)
				return rv;
			if (offset == 0)
				return -EINVAL;
1878 1879
			if (mddev->bitmap_info.external == 0 &&
			    mddev->major_version == 0 &&
1880 1881 1882 1883 1884 1885
			    offset != mddev->bitmap_info.default_offset)
				return -EINVAL;
			mddev->bitmap_info.offset = offset;
			if (mddev->pers) {
				mddev->pers->quiesce(mddev, 1);
				rv = bitmap_create(mddev);
1886 1887
				if (!rv)
					rv = bitmap_load(mddev);
1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910
				if (rv) {
					bitmap_destroy(mddev);
					mddev->bitmap_info.offset = 0;
				}
				mddev->pers->quiesce(mddev, 0);
				if (rv)
					return rv;
			}
		}
	}
	if (!mddev->external) {
		/* Ensure new bitmap info is stored in
		 * metadata promptly.
		 */
		set_bit(MD_CHANGE_DEVS, &mddev->flags);
		md_wakeup_thread(mddev->thread);
	}
	return len;
}

static struct md_sysfs_entry bitmap_location =
__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);

1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934
/* 'bitmap/space' is the space available at 'location' for the
 * bitmap.  This allows the kernel to know when it is safe to
 * resize the bitmap to match a resized array.
 */
static ssize_t
space_show(struct mddev *mddev, char *page)
{
	return sprintf(page, "%lu\n", mddev->bitmap_info.space);
}

static ssize_t
space_store(struct mddev *mddev, const char *buf, size_t len)
{
	unsigned long sectors;
	int rv;

	rv = kstrtoul(buf, 10, &sectors);
	if (rv)
		return rv;

	if (sectors == 0)
		return -EINVAL;

	if (mddev->bitmap &&
1935
	    sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947
		return -EFBIG; /* Bitmap is too big for this small space */

	/* could make sure it isn't too big, but that isn't really
	 * needed - user-space should be careful.
	 */
	mddev->bitmap_info.space = sectors;
	return len;
}

static struct md_sysfs_entry bitmap_space =
__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);

1948
static ssize_t
1949
timeout_show(struct mddev *mddev, char *page)
1950 1951 1952 1953
{
	ssize_t len;
	unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
	unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
1954

1955 1956 1957 1958 1959 1960 1961 1962
	len = sprintf(page, "%lu", secs);
	if (jifs)
		len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
	len += sprintf(page+len, "\n");
	return len;
}

static ssize_t
1963
timeout_store(struct mddev *mddev, const char *buf, size_t len)
1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
{
	/* timeout can be set at any time */
	unsigned long timeout;
	int rv = strict_strtoul_scaled(buf, &timeout, 4);
	if (rv)
		return rv;

	/* just to make sure we don't overflow... */
	if (timeout >= LONG_MAX / HZ)
		return -EINVAL;

	timeout = timeout * HZ / 10000;

	if (timeout >= MAX_SCHEDULE_TIMEOUT)
		timeout = MAX_SCHEDULE_TIMEOUT-1;
	if (timeout < 1)
		timeout = 1;
	mddev->bitmap_info.daemon_sleep = timeout;
	if (mddev->thread) {
		/* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
		 * the bitmap is all clean and we don't need to
		 * adjust the timeout right now
		 */
		if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
			mddev->thread->timeout = timeout;
			md_wakeup_thread(mddev->thread);
		}
	}
	return len;
}

static struct md_sysfs_entry bitmap_timeout =
__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);

static ssize_t
1999
backlog_show(struct mddev *mddev, char *page)
2000 2001 2002 2003 2004
{
	return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
}

static ssize_t
2005
backlog_store(struct mddev *mddev, const char *buf, size_t len)
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
{
	unsigned long backlog;
	int rv = strict_strtoul(buf, 10, &backlog);
	if (rv)
		return rv;
	if (backlog > COUNTER_MAX)
		return -EINVAL;
	mddev->bitmap_info.max_write_behind = backlog;
	return len;
}

static struct md_sysfs_entry bitmap_backlog =
__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);

static ssize_t
2021
chunksize_show(struct mddev *mddev, char *page)
2022 2023 2024 2025 2026
{
	return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
}

static ssize_t
2027
chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046
{
	/* Can only be changed when no bitmap is active */
	int rv;
	unsigned long csize;
	if (mddev->bitmap)
		return -EBUSY;
	rv = strict_strtoul(buf, 10, &csize);
	if (rv)
		return rv;
	if (csize < 512 ||
	    !is_power_of_2(csize))
		return -EINVAL;
	mddev->bitmap_info.chunksize = csize;
	return len;
}

static struct md_sysfs_entry bitmap_chunksize =
__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);

2047
static ssize_t metadata_show(struct mddev *mddev, char *page)
2048 2049 2050 2051 2052
{
	return sprintf(page, "%s\n", (mddev->bitmap_info.external
				      ? "external" : "internal"));
}

2053
static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070
{
	if (mddev->bitmap ||
	    mddev->bitmap_info.file ||
	    mddev->bitmap_info.offset)
		return -EBUSY;
	if (strncmp(buf, "external", 8) == 0)
		mddev->bitmap_info.external = 1;
	else if (strncmp(buf, "internal", 8) == 0)
		mddev->bitmap_info.external = 0;
	else
		return -EINVAL;
	return len;
}

static struct md_sysfs_entry bitmap_metadata =
__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);

2071
static ssize_t can_clear_show(struct mddev *mddev, char *page)
2072 2073 2074 2075 2076 2077 2078 2079 2080 2081
{
	int len;
	if (mddev->bitmap)
		len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
					     "false" : "true"));
	else
		len = sprintf(page, "\n");
	return len;
}

2082
static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099
{
	if (mddev->bitmap == NULL)
		return -ENOENT;
	if (strncmp(buf, "false", 5) == 0)
		mddev->bitmap->need_sync = 1;
	else if (strncmp(buf, "true", 4) == 0) {
		if (mddev->degraded)
			return -EBUSY;
		mddev->bitmap->need_sync = 0;
	} else
		return -EINVAL;
	return len;
}

static struct md_sysfs_entry bitmap_can_clear =
__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);

2100
static ssize_t
2101
behind_writes_used_show(struct mddev *mddev, char *page)
2102 2103 2104 2105 2106 2107 2108 2109
{
	if (mddev->bitmap == NULL)
		return sprintf(page, "0\n");
	return sprintf(page, "%lu\n",
		       mddev->bitmap->behind_writes_used);
}

static ssize_t
2110
behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2111 2112 2113 2114 2115 2116 2117 2118 2119 2120
{
	if (mddev->bitmap)
		mddev->bitmap->behind_writes_used = 0;
	return len;
}

static struct md_sysfs_entry max_backlog_used =
__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
       behind_writes_used_show, behind_writes_used_reset);

2121 2122
static struct attribute *md_bitmap_attrs[] = {
	&bitmap_location.attr,
2123
	&bitmap_space.attr,
2124 2125 2126
	&bitmap_timeout.attr,
	&bitmap_backlog.attr,
	&bitmap_chunksize.attr,
2127 2128
	&bitmap_metadata.attr,
	&bitmap_can_clear.attr,
2129
	&max_backlog_used.attr,
2130 2131 2132 2133 2134 2135 2136
	NULL
};
struct attribute_group md_bitmap_group = {
	.name = "bitmap",
	.attrs = md_bitmap_attrs,
};