Commit b405fe91 authored by NeilBrown's avatar NeilBrown
Browse files

md/bitmap: use set_bit, test_bit, etc for operation on bitmap->flags. 



We currently use '&' and '|' which isn't the norm in the kernel
and doesn't allow easy atomicity.
So change to bit numbers and {set,clear,test}_bit.
This allows us to remove a spinlock/unlock (which was dubious anyway)
and some other simplifications.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 84e92345

drivers/md/bitmap.c

+21 −25
Original line number Diff line number Diff line
@@ -271,7 +271,7 @@ static void write_page(struct bitmap *bitmap, struct page *page, int wait) 
	if (bitmap->storage.file == NULL) {

		switch (write_sb_page(bitmap, page, wait)) {

		case -EINVAL:

			bitmap->flags |= BITMAP_WRITE_ERROR;

			set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);

		}

	} else {
@@ -289,20 +289,16 @@ static void write_page(struct bitmap *bitmap, struct page *page, int wait) 
			wait_event(bitmap->write_wait,

				   atomic_read(&bitmap->pending_writes)==0);

	}

	if (bitmap->flags & BITMAP_WRITE_ERROR)

	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))

		bitmap_file_kick(bitmap);

}



static void end_bitmap_write(struct buffer_head *bh, int uptodate)

{

	struct bitmap *bitmap = bh->b_private;

	unsigned long flags;



	if (!uptodate) {

		spin_lock_irqsave(&bitmap->lock, flags);

		bitmap->flags |= BITMAP_WRITE_ERROR;

		spin_unlock_irqrestore(&bitmap->lock, flags);

	}

	if (!uptodate)

		set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);

	if (atomic_dec_and_test(&bitmap->pending_writes))

		wake_up(&bitmap->write_wait);

}
@@ -389,7 +385,7 @@ static int read_page(struct file *file, unsigned long index, 


	wait_event(bitmap->write_wait,

		   atomic_read(&bitmap->pending_writes)==0);

	if (bitmap->flags & BITMAP_WRITE_ERROR)

	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))

		ret = -EIO;

out:

	if (ret)
@@ -521,7 +517,7 @@ static int bitmap_new_disk_sb(struct bitmap *bitmap) 


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



	bitmap->flags |= BITMAP_STALE;

	set_bit(BITMAP_STALE, &bitmap->flags);

	sb->state = cpu_to_le32(bitmap->flags);

	bitmap->events_cleared = bitmap->mddev->events;

	sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
@@ -545,7 +541,7 @@ static int bitmap_read_sb(struct bitmap *bitmap) 
		chunksize = 128 * 1024 * 1024;

		daemon_sleep = 5 * HZ;

		write_behind = 0;

		bitmap->flags = BITMAP_STALE;

		set_bit(BITMAP_STALE, &bitmap->flags);

		err = 0;

		goto out_no_sb;

	}
@@ -617,20 +613,20 @@ static int bitmap_read_sb(struct bitmap *bitmap) 
			       "-- forcing full recovery\n",

			       bmname(bitmap), events,

			       (unsigned long long) bitmap->mddev->events);

			bitmap->flags |= BITMAP_STALE;

			set_bit(BITMAP_STALE, &bitmap->flags);

		}

	}



	/* assign fields using values from superblock */

	bitmap->flags |= le32_to_cpu(sb->state);

	if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)

		bitmap->flags |= BITMAP_HOSTENDIAN;

		set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);

	bitmap->events_cleared = le64_to_cpu(sb->events_cleared);

	err = 0;

out:

	kunmap_atomic(sb);

out_no_sb:

	if (bitmap->flags & BITMAP_STALE)

	if (test_bit(BITMAP_STALE, &bitmap->flags))

		bitmap->events_cleared = bitmap->mddev->events;

	bitmap->mddev->bitmap_info.chunksize = chunksize;

	bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
@@ -796,8 +792,7 @@ static void bitmap_file_kick(struct bitmap *bitmap) 
{

	char *path, *ptr = NULL;



	if (!(bitmap->flags & BITMAP_STALE)) {

		bitmap->flags |= BITMAP_STALE;

	if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {

		bitmap_update_sb(bitmap);



		if (bitmap->storage.file) {
@@ -868,7 +863,7 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block) 


	/* set the bit */

	kaddr = kmap_atomic(page);

	if (bitmap->flags & BITMAP_HOSTENDIAN)

	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))

		set_bit(bit, kaddr);

	else

		__set_bit_le(bit, kaddr);
@@ -890,7 +885,7 @@ static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block) 
		return;

	bit = file_page_offset(&bitmap->storage, chunk);

	paddr = kmap_atomic(page);

	if (bitmap->flags & BITMAP_HOSTENDIAN)

	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))

		clear_bit(bit, paddr);

	else

		__clear_bit_le(bit, paddr);
@@ -941,7 +936,7 @@ void bitmap_unplug(struct bitmap *bitmap) 
		else

			md_super_wait(bitmap->mddev);

	}

	if (bitmap->flags & BITMAP_WRITE_ERROR)

	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))

		bitmap_file_kick(bitmap);

}

EXPORT_SYMBOL(bitmap_unplug);
@@ -988,7 +983,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) 
		return 0;

	}



	outofdate = bitmap->flags & BITMAP_STALE;

	outofdate = test_bit(BITMAP_STALE, &bitmap->flags);

	if (outofdate)

		printk(KERN_INFO "%s: bitmap file is out of date, doing full "

			"recovery\n", bmname(bitmap));
@@ -1045,12 +1040,13 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) 
				write_page(bitmap, page, 1);



				ret = -EIO;

				if (bitmap->flags & BITMAP_WRITE_ERROR)

				if (test_bit(BITMAP_WRITE_ERROR,

					     &bitmap->flags))

					goto err;

			}

		}

		paddr = kmap_atomic(page);

		if (bitmap->flags & BITMAP_HOSTENDIAN)

		if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))

			b = test_bit(bit, paddr);

		else

			b = test_bit_le(bit, paddr);
@@ -1758,7 +1754,7 @@ int bitmap_create(struct mddev *mddev) 
	mddev->bitmap = bitmap;





	return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;

	return test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;



 error:

	bitmap_free(bitmap);
@@ -1799,7 +1795,7 @@ int bitmap_load(struct mddev *mddev) 


	if (err)

		goto out;

	bitmap->flags &= ~BITMAP_STALE;

	clear_bit(BITMAP_STALE, &bitmap->flags);



	/* Kick recovery in case any bits were set */

	set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
@@ -1809,7 +1805,7 @@ int bitmap_load(struct mddev *mddev) 


	bitmap_update_sb(bitmap);



	if (bitmap->flags & BITMAP_WRITE_ERROR)

	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))

		err = -EIO;

out:

	return err;

drivers/md/bitmap.h

+3 −3
Original line number Diff line number Diff line
@@ -111,9 +111,9 @@ typedef __u16 bitmap_counter_t; 


/* use these for bitmap->flags and bitmap->sb->state bit-fields */

enum bitmap_state {

	BITMAP_STALE  = 0x002,  /* the bitmap file is out of date or had -EIO */

	BITMAP_WRITE_ERROR = 0x004, /* A write error has occurred */

	BITMAP_HOSTENDIAN = 0x8000,

	BITMAP_STALE	   = 1,  /* the bitmap file is out of date or had -EIO */

	BITMAP_WRITE_ERROR = 2, /* A write error has occurred */

	BITMAP_HOSTENDIAN  =15,

};



/* the superblock at the front of the bitmap file -- little endian */