bitmap.c 54.9 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 */
88
		kfree(mappage);
89
		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

348 349
	pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
		 (unsigned long long)index << PAGE_SHIFT);
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351 352
	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);
415
	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;
544
		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
}

811 812
static inline int test_page_attr(struct bitmap *bitmap, int pnum,
				 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
static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
					   enum bitmap_page_attr attr)
{
	return test_and_clear_bit((pnum<<2) + attr,
				  bitmap->storage.filemap_attr);
}
823 824 825 826 827 828 829 830 831 832
/*
 * 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;
833
	struct page *page;
834
	void *kaddr;
835
	unsigned long chunk = block >> bitmap->chunkshift;
836

837
	page = filemap_get_page(&bitmap->storage, chunk);
838 839
	if (!page)
		return;
840
	bit = file_page_offset(&bitmap->storage, chunk);
841

842
	/* set the bit */
843
	kaddr = kmap_atomic(page);
844
	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
845 846
		set_bit(bit, kaddr);
	else
847
		test_and_set_bit_le(bit, kaddr);
848
	kunmap_atomic(kaddr);
849
	pr_debug("set file bit %lu page %lu\n", bit, page->index);
850
	/* record page number so it gets flushed to disk when unplug occurs */
851
	set_page_attr(bitmap, page->index, BITMAP_PAGE_DIRTY);
852 853
}

854 855 856 857 858 859 860
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;

861
	page = filemap_get_page(&bitmap->storage, chunk);
862 863
	if (!page)
		return;
864
	bit = file_page_offset(&bitmap->storage, chunk);
865
	paddr = kmap_atomic(page);
866
	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
867 868
		clear_bit(bit, paddr);
	else
869
		test_and_clear_bit_le(bit, paddr);
870
	kunmap_atomic(paddr);
871 872
	if (!test_page_attr(bitmap, page->index, BITMAP_PAGE_NEEDWRITE)) {
		set_page_attr(bitmap, page->index, BITMAP_PAGE_PENDING);
873 874 875 876
		bitmap->allclean = 0;
	}
}

877 878 879
/* 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 */
880
void bitmap_unplug(struct bitmap *bitmap)
881
{
882
	unsigned long i;
883
	int dirty, need_write;
884 885
	int wait = 0;

886 887
	if (!bitmap || !bitmap->storage.filemap ||
	    test_bit(BITMAP_STALE, &bitmap->flags))
888
		return;
889 890 891

	/* look at each page to see if there are any set bits that need to be
	 * flushed out to disk */
892
	for (i = 0; i < bitmap->storage.file_pages; i++) {
893
		if (!bitmap->storage.filemap)
894
			return;
895 896 897 898
		dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
		need_write = test_and_clear_page_attr(bitmap, i,
						      BITMAP_PAGE_NEEDWRITE);
		if (dirty || need_write) {
899
			clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
900 901
			write_page(bitmap, bitmap->storage.filemap[i], 0);
		}
902
		if (dirty)
903 904 905
			wait = 1;
	}
	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
	for (i = 0; i < bitmap->storage.file_pages; i++)
1066
		set_page_attr(bitmap, i,
1067
			      BITMAP_PAGE_NEEDWRITE);
1068
	bitmap->allclean = 0;
1069 1070
}

1071 1072
static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
{
1073
	sector_t chunk = offset >> bitmap->chunkshift;
1074 1075 1076 1077
	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
	bitmap->bp[page].count += inc;
	bitmap_checkfree(bitmap, page);
}
1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088

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;
}

1089
static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
N
NeilBrown 已提交
1090
					    sector_t offset, sector_t *blocks,
1091 1092 1093 1094 1095 1096 1097
					    int create);

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

1098
void bitmap_daemon_work(struct mddev *mddev)
1099
{
1100
	struct bitmap *bitmap;
1101
	unsigned long j;
1102
	unsigned long nextpage;
N
NeilBrown 已提交
1103
	sector_t blocks;
1104

1105 1106 1107
	/* Use a mutex to guard daemon_work against
	 * bitmap_destroy.
	 */
1108
	mutex_lock(&mddev->bitmap_info.mutex);
1109 1110
	bitmap = mddev->bitmap;
	if (bitmap == NULL) {
1111
		mutex_unlock(&mddev->bitmap_info.mutex);
1112
		return;
1113
	}
1114
	if (time_before(jiffies, bitmap->daemon_lastrun
N
NeilBrown 已提交
1115
			+ mddev->bitmap_info.daemon_sleep))
1116 1117
		goto done;

1118
	bitmap->daemon_lastrun = jiffies;
1119
	if (bitmap->allclean) {
N
NeilBrown 已提交
1120
		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1121
		goto done;
1122 1123
	}
	bitmap->allclean = 1;
1124

1125 1126 1127 1128
	/* 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.
	 */
1129
	for (j = 0; j < bitmap->storage.file_pages; j++)
1130 1131
		if (test_and_clear_page_attr(bitmap, j,
					     BITMAP_PAGE_PENDING))
1132
			set_page_attr(bitmap, j,
1133 1134 1135 1136 1137 1138 1139 1140
				      BITMAP_PAGE_NEEDWRITE);

	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;
1141 1142
		if (bitmap->storage.filemap) {
			sb = kmap_atomic(bitmap->storage.sb_page);
1143 1144 1145
			sb->events_cleared =
				cpu_to_le64(bitmap->events_cleared);
			kunmap_atomic(sb);
1146
			set_page_attr(bitmap, 0,
1147 1148
				      BITMAP_PAGE_NEEDWRITE);
		}
1149 1150 1151 1152
	}
	/* Now look at the bitmap counters and if any are '2' or '1',
	 * decrement and handle accordingly.
	 */
1153
	spin_lock_irq(&bitmap->lock);
1154
	nextpage = 0;
1155 1156
	for (j = 0; j < bitmap->chunks; j++) {
		bitmap_counter_t *bmc;
1157
		sector_t  block = (sector_t)j << bitmap->chunkshift;
1158

1159 1160 1161 1162
		if (j == nextpage) {
			nextpage += PAGE_COUNTER_RATIO;
			if (!bitmap->bp[j >> PAGE_COUNTER_SHIFT].pending) {
				j |= PAGE_COUNTER_MASK;
1163 1164
				continue;
			}
1165
			bitmap->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
1166
		}
1167
		bmc = bitmap_get_counter(bitmap,
1168
					 block,
1169
					 &blocks, 0);
1170 1171

		if (!bmc) {
1172
			j |= PAGE_COUNTER_MASK;
1173 1174 1175 1176 1177
			continue;
		}
		if (*bmc == 1 && !bitmap->need_sync) {
			/* We can clear the bit */
			*bmc = 0;
1178 1179
			bitmap_count_page(bitmap, block, -1);
			bitmap_file_clear_bit(bitmap, block);
1180 1181
		} else if (*bmc && *bmc <= 2) {
			*bmc = 1;
1182
			bitmap_set_pending(bitmap, block);
1183
			bitmap->allclean = 0;
1184
		}
1185
	}
1186
	spin_unlock_irq(&bitmap->lock);
1187

1188 1189 1190 1191 1192 1193 1194 1195
	/* 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.
	 */
1196 1197 1198 1199
	for (j = 0;
	     j < bitmap->storage.file_pages
		     && !test_bit(BITMAP_STALE, &bitmap->flags);
	     j++) {
1200

1201
		if (test_page_attr(bitmap, j,
1202 1203 1204
				   BITMAP_PAGE_DIRTY))
			/* bitmap_unplug will handle the rest */
			break;
1205 1206
		if (test_and_clear_page_attr(bitmap, j,
					     BITMAP_PAGE_NEEDWRITE)) {
1207
			write_page(bitmap, bitmap->storage.filemap[j], 0);
1208 1209 1210
		}
	}

1211
 done:
1212
	if (bitmap->allclean == 0)
N
NeilBrown 已提交
1213 1214
		mddev->thread->timeout =
			mddev->bitmap_info.daemon_sleep;
1215
	mutex_unlock(&mddev->bitmap_info.mutex);
1216 1217 1218
}

static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
N
NeilBrown 已提交
1219
					    sector_t offset, sector_t *blocks,
1220
					    int create)
1221 1222
__releases(bitmap->lock)
__acquires(bitmap->lock)
1223 1224 1225 1226 1227
{
	/* 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.
	 */
1228
	sector_t chunk = offset >> bitmap->chunkshift;
1229 1230 1231
	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
	unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
	sector_t csize;
1232
	int err;
1233

1234 1235 1236 1237
	err = bitmap_checkpage(bitmap, page, create);

	if (bitmap->bp[page].hijacked ||
	    bitmap->bp[page].map == NULL)
1238
		csize = ((sector_t)1) << (bitmap->chunkshift +
1239 1240
					  PAGE_COUNTER_SHIFT - 1);
	else
1241
		csize = ((sector_t)1) << bitmap->chunkshift;
1242 1243 1244
	*blocks = csize - (offset & (csize - 1));

	if (err < 0)
1245
		return NULL;
1246

1247 1248 1249 1250 1251 1252 1253 1254
	/* 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];
1255
	} else /* page is allocated */
1256 1257 1258 1259
		return (bitmap_counter_t *)
			&(bitmap->bp[page].map[pageoff]);
}

1260
int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
1261
{
1262 1263
	if (!bitmap)
		return 0;
1264 1265

	if (behind) {
1266
		int bw;
1267
		atomic_inc(&bitmap->behind_writes);
1268 1269 1270 1271
		bw = atomic_read(&bitmap->behind_writes);
		if (bw > bitmap->behind_writes_used)
			bitmap->behind_writes_used = bw;

1272 1273
		pr_debug("inc write-behind count %d/%lu\n",
			 bw, bitmap->mddev->bitmap_info.max_write_behind);
1274 1275
	}

1276
	while (sectors) {
N
NeilBrown 已提交
1277
		sector_t blocks;
1278 1279 1280 1281 1282 1283 1284 1285 1286
		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;
		}

1287
		if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
1288 1289 1290 1291 1292 1293 1294 1295
			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
1296
			io_schedule();
1297 1298 1299 1300
			finish_wait(&bitmap->overflow_wait, &__wait);
			continue;
		}

1301
		switch (*bmc) {
1302 1303
		case 0:
			bitmap_file_set_bit(bitmap, offset);
1304
			bitmap_count_page(bitmap, offset, 1);
1305 1306 1307 1308
			/* fall through */
		case 1:
			*bmc = 2;
		}
1309

1310 1311 1312 1313 1314 1315 1316
		(*bmc)++;

		spin_unlock_irq(&bitmap->lock);

		offset += blocks;
		if (sectors > blocks)
			sectors -= blocks;
1317 1318
		else
			sectors = 0;
1319 1320 1321
	}
	return 0;
}
1322
EXPORT_SYMBOL(bitmap_startwrite);
1323 1324

void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
1325
		     int success, int behind)
1326
{
1327 1328
	if (!bitmap)
		return;
1329
	if (behind) {
1330 1331
		if (atomic_dec_and_test(&bitmap->behind_writes))
			wake_up(&bitmap->behind_wait);
1332 1333 1334
		pr_debug("dec write-behind count %d/%lu\n",
			 atomic_read(&bitmap->behind_writes),
			 bitmap->mddev->bitmap_info.max_write_behind);
1335 1336
	}

1337
	while (sectors) {
N
NeilBrown 已提交
1338
		sector_t blocks;
1339 1340 1341 1342 1343 1344 1345 1346 1347 1348
		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;
		}

1349
		if (success && !bitmap->mddev->degraded &&
1350 1351 1352
		    bitmap->events_cleared < bitmap->mddev->events) {
			bitmap->events_cleared = bitmap->mddev->events;
			bitmap->need_sync = 1;
1353
			sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
1354 1355
		}

1356
		if (!success && !NEEDED(*bmc))
1357 1358
			*bmc |= NEEDED_MASK;

1359
		if (COUNTER(*bmc) == COUNTER_MAX)
1360 1361
			wake_up(&bitmap->overflow_wait);

1362
		(*bmc)--;
1363
		if (*bmc <= 2) {
1364
			bitmap_set_pending(bitmap, offset);
1365 1366
			bitmap->allclean = 0;
		}
1367 1368 1369 1370
		spin_unlock_irqrestore(&bitmap->lock, flags);
		offset += blocks;
		if (sectors > blocks)
			sectors -= blocks;
1371 1372
		else
			sectors = 0;
1373 1374
	}
}
1375
EXPORT_SYMBOL(bitmap_endwrite);
1376

N
NeilBrown 已提交
1377
static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1378
			       int degraded)
1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394
{
	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;
1395 1396 1397 1398
			if (!degraded) { /* don't set/clear bits if degraded */
				*bmc |= RESYNC_MASK;
				*bmc &= ~NEEDED_MASK;
			}
1399 1400 1401 1402 1403 1404
		}
	}
	spin_unlock_irq(&bitmap->lock);
	return rv;
}

N
NeilBrown 已提交
1405
int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
1406 1407 1408 1409 1410 1411 1412 1413 1414 1415
		      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
1416
	sector_t blocks1;
1417 1418 1419 1420 1421 1422 1423 1424 1425 1426

	*blocks = 0;
	while (*blocks < (PAGE_SIZE>>9)) {
		rv |= __bitmap_start_sync(bitmap, offset,
					  &blocks1, degraded);
		offset += blocks1;
		*blocks += blocks1;
	}
	return rv;
}
1427
EXPORT_SYMBOL(bitmap_start_sync);
1428

N
NeilBrown 已提交
1429
void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
1430 1431 1432
{
	bitmap_counter_t *bmc;
	unsigned long flags;
1433 1434

	if (bitmap == NULL) {
1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448
		*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 {
1449
			if (*bmc <= 2) {
1450
				bitmap_set_pending(bitmap, offset);
1451 1452
				bitmap->allclean = 0;
			}
1453 1454 1455 1456 1457
		}
	}
 unlock:
	spin_unlock_irqrestore(&bitmap->lock, flags);
}
1458
EXPORT_SYMBOL(bitmap_end_sync);
1459 1460 1461 1462 1463 1464 1465 1466

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

void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
{
	sector_t s = 0;
N
NeilBrown 已提交
1480
	sector_t blocks;
N
NeilBrown 已提交
1481 1482 1483 1484 1485 1486 1487 1488

	if (!bitmap)
		return;
	if (sector == 0) {
		bitmap->last_end_sync = jiffies;
		return;
	}
	if (time_before(jiffies, (bitmap->last_end_sync
1489
				  + bitmap->mddev->bitmap_info.daemon_sleep)))
N
NeilBrown 已提交
1490 1491 1492 1493
		return;
	wait_event(bitmap->mddev->recovery_wait,
		   atomic_read(&bitmap->mddev->recovery_active) == 0);

1494
	bitmap->mddev->curr_resync_completed = sector;
1495
	set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
1496
	sector &= ~((1ULL << bitmap->chunkshift) - 1);
N
NeilBrown 已提交
1497 1498 1499 1500
	s = 0;
	while (s < sector && s < bitmap->mddev->resync_max_sectors) {
		bitmap_end_sync(bitmap, s, &blocks, 0);
		s += blocks;
1501
	}
N
NeilBrown 已提交
1502
	bitmap->last_end_sync = jiffies;
1503
	sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
1504
}
1505
EXPORT_SYMBOL(bitmap_cond_end_sync);
1506

1507
static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
1508 1509
{
	/* For each chunk covered by any of these sectors, set the
1510
	 * counter to 2 and possibly set resync_needed.  They should all
1511 1512
	 * be 0 at this point
	 */
1513

N
NeilBrown 已提交
1514
	sector_t secs;
1515 1516 1517 1518
	bitmap_counter_t *bmc;
	spin_lock_irq(&bitmap->lock);
	bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
	if (!bmc) {
1519
		spin_unlock_irq(&bitmap->lock);
1520
		return;
1521
	}
1522
	if (!*bmc) {
1523
		*bmc = 2 | (needed ? NEEDED_MASK : 0);
1524
		bitmap_count_page(bitmap, offset, 1);
1525
		bitmap_set_pending(bitmap, offset);
1526
		bitmap->allclean = 0;
1527 1528
	}
	spin_unlock_irq(&bitmap->lock);
1529 1530
}

1531 1532 1533 1534 1535 1536
/* 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++) {
1537
		sector_t sec = (sector_t)chunk << bitmap->chunkshift;
1538 1539
		bitmap_set_memory_bits(bitmap, sec, 1);
		bitmap_file_set_bit(bitmap, sec);
1540 1541 1542 1543 1544 1545
		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;
1546 1547 1548
	}
}

1549 1550 1551
/*
 * flush out any pending updates
 */
1552
void bitmap_flush(struct mddev *mddev)
1553 1554
{
	struct bitmap *bitmap = mddev->bitmap;
1555
	long sleep;
1556 1557 1558 1559 1560 1561 1562

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

	/* run the daemon_work three time to ensure everything is flushed
	 * that can be
	 */
1563
	sleep = mddev->bitmap_info.daemon_sleep * 2;
1564
	bitmap->daemon_lastrun -= sleep;
1565
	bitmap_daemon_work(mddev);
1566
	bitmap->daemon_lastrun -= sleep;
1567
	bitmap_daemon_work(mddev);
1568
	bitmap->daemon_lastrun -= sleep;
1569
	bitmap_daemon_work(mddev);
1570 1571 1572
	bitmap_update_sb(bitmap);
}

1573 1574 1575
/*
 * free memory that was allocated
 */
1576
static void bitmap_free(struct bitmap *bitmap)
1577 1578 1579 1580 1581 1582 1583
{
	unsigned long k, pages;
	struct bitmap_page *bp;

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

1584 1585 1586 1587 1588 1589
	/* 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);
1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602

	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);
}
1603

1604
void bitmap_destroy(struct mddev *mddev)
1605 1606 1607 1608 1609 1610
{
	struct bitmap *bitmap = mddev->bitmap;

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

1611
	mutex_lock(&mddev->bitmap_info.mutex);
1612
	mddev->bitmap = NULL; /* disconnect from the md device */
1613
	mutex_unlock(&mddev->bitmap_info.mutex);
1614 1615
	if (mddev->thread)
		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
1616

1617 1618 1619
	if (bitmap->sysfs_can_clear)
		sysfs_put(bitmap->sysfs_can_clear);

1620 1621
	bitmap_free(bitmap);
}
1622 1623 1624 1625 1626

/*
 * initialize the bitmap structure
 * if this returns an error, bitmap_destroy must be called to do clean up
 */
1627
int bitmap_create(struct mddev *mddev)
1628 1629
{
	struct bitmap *bitmap;
1630
	sector_t blocks = mddev->resync_max_sectors;
1631 1632
	unsigned long chunks;
	unsigned long pages;
1633
	struct file *file = mddev->bitmap_info.file;
1634
	int err;
1635
	struct sysfs_dirent *bm = NULL;
1636

A
Alexey Dobriyan 已提交
1637
	BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
1638

1639
	BUG_ON(file && mddev->bitmap_info.offset);
1640

1641
	bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
1642 1643 1644 1645
	if (!bitmap)
		return -ENOMEM;

	spin_lock_init(&bitmap->lock);
1646 1647
	atomic_set(&bitmap->pending_writes, 0);
	init_waitqueue_head(&bitmap->write_wait);
1648
	init_waitqueue_head(&bitmap->overflow_wait);
1649
	init_waitqueue_head(&bitmap->behind_wait);
1650

1651 1652
	bitmap->mddev = mddev;

1653 1654
	if (mddev->kobj.sd)
		bm = sysfs_get_dirent(mddev->kobj.sd, NULL, "bitmap");
1655
	if (bm) {
1656
		bitmap->sysfs_can_clear = sysfs_get_dirent(bm, NULL, "can_clear");
1657 1658 1659 1660
		sysfs_put(bm);
	} else
		bitmap->sysfs_can_clear = NULL;

1661
	bitmap->storage.file = file;
1662 1663
	if (file) {
		get_file(file);
1664 1665 1666 1667
		/* As future accesses to this file will use bmap,
		 * and bypass the page cache, we must sync the file
		 * first.
		 */
1668
		vfs_fsync(file, 1);
1669
	}
1670
	/* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
1671 1672 1673 1674 1675 1676 1677 1678 1679 1680
	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 {
1681 1682 1683 1684 1685 1686 1687
		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;
	}
1688
	if (err)
1689
		goto error;
1690

1691
	bitmap->daemon_lastrun = jiffies;
1692 1693
	bitmap->chunkshift = (ffz(~mddev->bitmap_info.chunksize)
			      - BITMAP_BLOCK_SHIFT);
1694

1695
	chunks = (blocks + (1 << bitmap->chunkshift) - 1) >>
1696
			bitmap->chunkshift;
1697
	pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
1698 1699 1700 1701 1702 1703 1704

	BUG_ON(!pages);

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

1705
	bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
1706

1707
	err = -ENOMEM;
1708
	if (!bitmap->bp)
1709
		goto error;
1710

1711 1712 1713 1714 1715 1716
	if (file || mddev->bitmap_info.offset) {
		err = bitmap_storage_alloc(&bitmap->storage, bitmap->chunks,
					   !mddev->bitmap_info.external);
		if (err)
			goto error;
	}
1717 1718 1719 1720 1721 1722
	printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
		pages, bmname(bitmap));

	mddev->bitmap = bitmap;


1723
	return test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
1724 1725 1726 1727 1728 1729

 error:
	bitmap_free(bitmap);
	return err;
}

1730
int bitmap_load(struct mddev *mddev)
1731 1732
{
	int err = 0;
1733
	sector_t start = 0;
1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745
	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
1746
		sector_t blocks;
1747 1748 1749 1750 1751
		bitmap_start_sync(bitmap, sector, &blocks, 0);
		sector += blocks;
	}
	bitmap_close_sync(bitmap);

1752 1753 1754 1755 1756 1757
	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;

1758
	mutex_lock(&mddev->bitmap_info.mutex);
1759
	err = bitmap_init_from_disk(bitmap, start);
1760
	mutex_unlock(&mddev->bitmap_info.mutex);
1761

1762
	if (err)
1763
		goto out;
1764
	clear_bit(BITMAP_STALE, &bitmap->flags);
1765 1766 1767

	/* Kick recovery in case any bits were set */
	set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
1768

1769
	mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
1770
	md_wakeup_thread(mddev->thread);
1771

1772 1773
	bitmap_update_sb(bitmap);

1774
	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
1775 1776
		err = -EIO;
out:
1777
	return err;
1778
}
1779
EXPORT_SYMBOL_GPL(bitmap_load);
1780

1781 1782 1783 1784 1785 1786 1787
void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
{
	unsigned long chunk_kb;

	if (!bitmap)
		return;

1788
	spin_lock_irq(&bitmap->lock);
1789 1790 1791 1792 1793 1794 1795 1796 1797
	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");
1798
	if (bitmap->storage.file) {
1799
		seq_printf(seq, ", file: ");
1800
		seq_path(seq, &bitmap->storage.file->f_path, " \t\n");
1801 1802 1803
	}

	seq_printf(seq, "\n");
1804
	spin_unlock_irq(&bitmap->lock);
1805 1806
}

1807
static ssize_t
1808
location_show(struct mddev *mddev, char *page)
1809 1810
{
	ssize_t len;
1811
	if (mddev->bitmap_info.file)
1812
		len = sprintf(page, "file");
1813
	else if (mddev->bitmap_info.offset)
1814
		len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
1815
	else
1816 1817 1818 1819 1820 1821
		len = sprintf(page, "none");
	len += sprintf(page+len, "\n");
	return len;
}

static ssize_t
1822
location_store(struct mddev *mddev, const char *buf, size_t len)
1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 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
{

	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;
1867 1868
			if (mddev->bitmap_info.external == 0 &&
			    mddev->major_version == 0 &&
1869 1870 1871 1872 1873 1874
			    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);
1875 1876
				if (!rv)
					rv = bitmap_load(mddev);
1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899
				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);

1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923
/* '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 &&
1924
	    sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936
		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);

1937
static ssize_t
1938
timeout_show(struct mddev *mddev, char *page)
1939 1940 1941 1942
{
	ssize_t len;
	unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
	unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
1943

1944 1945 1946 1947 1948 1949 1950 1951
	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
1952
timeout_store(struct mddev *mddev, const char *buf, size_t len)
1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987
{
	/* 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
1988
backlog_show(struct mddev *mddev, char *page)
1989 1990 1991 1992 1993
{
	return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
}

static ssize_t
1994
backlog_store(struct mddev *mddev, const char *buf, size_t len)
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
{
	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
2010
chunksize_show(struct mddev *mddev, char *page)
2011 2012 2013 2014 2015
{
	return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
}

static ssize_t
2016
chunksize_store(struct mddev *mddev, const char *buf, size_t len)
2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
{
	/* 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);

2036
static ssize_t metadata_show(struct mddev *mddev, char *page)
2037 2038 2039 2040 2041
{
	return sprintf(page, "%s\n", (mddev->bitmap_info.external
				      ? "external" : "internal"));
}

2042
static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059
{
	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);

2060
static ssize_t can_clear_show(struct mddev *mddev, char *page)
2061 2062 2063 2064 2065 2066 2067 2068 2069 2070
{
	int len;
	if (mddev->bitmap)
		len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
					     "false" : "true"));
	else
		len = sprintf(page, "\n");
	return len;
}

2071
static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088
{
	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);

2089
static ssize_t
2090
behind_writes_used_show(struct mddev *mddev, char *page)
2091 2092 2093 2094 2095 2096 2097 2098
{
	if (mddev->bitmap == NULL)
		return sprintf(page, "0\n");
	return sprintf(page, "%lu\n",
		       mddev->bitmap->behind_writes_used);
}

static ssize_t
2099
behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
2100 2101 2102 2103 2104 2105 2106 2107 2108 2109
{
	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);

2110 2111
static struct attribute *md_bitmap_attrs[] = {
	&bitmap_location.attr,
2112
	&bitmap_space.attr,
2113 2114 2115
	&bitmap_timeout.attr,
	&bitmap_backlog.attr,
	&bitmap_chunksize.attr,
2116 2117
	&bitmap_metadata.attr,
	&bitmap_can_clear.attr,
2118
	&max_backlog_used.attr,
2119 2120 2121 2122 2123 2124 2125
	NULL
};
struct attribute_group md_bitmap_group = {
	.name = "bitmap",
	.attrs = md_bitmap_attrs,
};