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[PATCH] md: make md on-disk bitmaps not host-endian

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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>
This commit is contained in:
NeilBrown
2005-11-08 21:39:32 -08:00
committed by Linus Torvalds
parent b2d444d7ad
commit bd926c63b7
4 changed files with 31 additions and 8 deletions
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22
drivers/md/bitmap.c
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@@ -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);