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authorNeilBrown <neilb@suse.de>2005-11-08 21:39:32 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-11-09 07:56:38 -0800
commitbd926c63b7a6843d3ce2728396c0891e54fce5c4 (patch)
tree38f7083a733e9b31efe69616c5fa3448c74c1320 /drivers/md/bitmap.c
parentb2d444d7ad975d555bb919601bcdc0e58975a40e (diff)
[PATCH] md: make md on-disk bitmaps not host-endian
Current bitmaps use set_bit et.al and so are host-endian, which means not-portable. Oops. Define a new version number (4) for which bitmaps are little-endian. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/md/bitmap.c')
-rw-r--r--drivers/md/bitmap.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index c5fa4c2a5af1..220273e81ed6 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -482,7 +482,8 @@ static int bitmap_read_sb(struct bitmap *bitmap)
/* verify that the bitmap-specific fields are valid */
if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
reason = "bad magic";
- else if (sb->version != cpu_to_le32(BITMAP_MAJOR))
+ else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
+ le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
reason = "unrecognized superblock version";
else if (chunksize < 512 || chunksize > (1024 * 1024 * 4))
reason = "bitmap chunksize out of range (512B - 4MB)";
@@ -527,6 +528,8 @@ success:
bitmap->daemon_lastrun = jiffies;
bitmap->max_write_behind = write_behind;
bitmap->flags |= sb->state;
+ if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
+ bitmap->flags |= BITMAP_HOSTENDIAN;
bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
if (sb->state & BITMAP_STALE)
bitmap->events_cleared = bitmap->mddev->events;
@@ -764,7 +767,10 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
/* set the bit */
kaddr = kmap_atomic(page, KM_USER0);
- set_bit(bit, kaddr);
+ if (bitmap->flags & BITMAP_HOSTENDIAN)
+ set_bit(bit, kaddr);
+ else
+ ext2_set_bit(bit, kaddr);
kunmap_atomic(kaddr, KM_USER0);
PRINTK("set file bit %lu page %lu\n", bit, page->index);
@@ -891,6 +897,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
oldindex = ~0L;
for (i = 0; i < chunks; i++) {
+ int b;
index = file_page_index(i);
bit = file_page_offset(i);
if (index != oldindex) { /* this is a new page, read it in */
@@ -939,7 +946,11 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
bitmap->filemap[bitmap->file_pages++] = page;
}
- if (test_bit(bit, page_address(page))) {
+ if (bitmap->flags & BITMAP_HOSTENDIAN)
+ b = test_bit(bit, page_address(page));
+ else
+ b = ext2_test_bit(bit, page_address(page));
+ if (b) {
/* if the disk bit is set, set the memory bit */
bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap),
((i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) >= start)
@@ -1097,7 +1108,10 @@ int bitmap_daemon_work(struct bitmap *bitmap)
-1);
/* clear the bit */
- clear_bit(file_page_offset(j), page_address(page));
+ if (bitmap->flags & BITMAP_HOSTENDIAN)
+ clear_bit(file_page_offset(j), page_address(page));
+ else
+ ext2_clear_bit(file_page_offset(j), page_address(page));
}
}
spin_unlock_irqrestore(&bitmap->lock, flags);