md/bitmap: make bitmap bitops atomic.

This allows us to remove spinlock protection which is
more heavy-weight than simple atomics.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 2e2f53c..7c3c1c5 100644 (file)
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -844,7 +844,7 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
        if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
                set_bit(bit, kaddr);
        else
-               __set_bit_le(bit, kaddr);
+               test_and_set_bit_le(bit, kaddr);
        kunmap_atomic(kaddr);
        pr_debug("set file bit %lu page %lu\n", bit, page->index);
        /* record page number so it gets flushed to disk when unplug occurs */
@@ -866,7 +866,7 @@ static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
        if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
                clear_bit(bit, paddr);
        else
-               __clear_bit_le(bit, paddr);
+               test_and_clear_bit_le(bit, paddr);
        kunmap_atomic(paddr);
        if (!test_page_attr(bitmap, page->index, BITMAP_PAGE_NEEDWRITE)) {
                set_page_attr(bitmap, page->index, BITMAP_PAGE_PENDING);
@@ -1536,9 +1536,7 @@ void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
        for (chunk = s; chunk <= e; chunk++) {
                sector_t sec = (sector_t)chunk << bitmap->chunkshift;
                bitmap_set_memory_bits(bitmap, sec, 1);
-               spin_lock_irq(&bitmap->lock);
                bitmap_file_set_bit(bitmap, sec);
-               spin_unlock_irq(&bitmap->lock);
                if (sec < bitmap->mddev->recovery_cp)
                        /* We are asserting that the array is dirty,
                         * so move the recovery_cp address back so