[PATCH] md: allow md intent bitmap to be stored near the superblock.
This provides an alternate to storing the bitmap in a separate file. The
bitmap can be stored at a given offset from the superblock. Obviously the
creator of the array must make sure this doesn't intersect with data....
After is good for version-0.90 superblocks.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 7075beb..fde8acf 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -337,7 +337,7 @@
return 0;
}
-static int sync_page_io(struct block_device *bdev, sector_t sector, int size,
+int sync_page_io(struct block_device *bdev, sector_t sector, int size,
struct page *page, int rw)
{
struct bio *bio = bio_alloc(GFP_NOIO, 1);
@@ -609,6 +609,17 @@
memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
mddev->max_disks = MD_SB_DISKS;
+
+ if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
+ mddev->bitmap_file == NULL) {
+ if (mddev->level != 1) {
+ /* FIXME use a better test */
+ printk(KERN_WARNING "md: bitmaps only support for raid1\n");
+ return -EINVAL;
+ }
+ mddev->bitmap_offset = (MD_SB_BYTES >> 9);
+ }
+
} else if (mddev->pers == NULL) {
/* Insist on good event counter while assembling */
__u64 ev1 = md_event(sb);
@@ -702,6 +713,9 @@
sb->layout = mddev->layout;
sb->chunk_size = mddev->chunk_size;
+ if (mddev->bitmap && mddev->bitmap_file == NULL)
+ sb->state |= (1<<MD_SB_BITMAP_PRESENT);
+
sb->disks[0].state = (1<<MD_DISK_REMOVED);
ITERATE_RDEV(mddev,rdev2,tmp) {
mdp_disk_t *d;
@@ -898,6 +912,15 @@
memcpy(mddev->uuid, sb->set_uuid, 16);
mddev->max_disks = (4096-256)/2;
+
+ if ((le32_to_cpu(sb->feature_map) & 1) &&
+ mddev->bitmap_file == NULL ) {
+ if (mddev->level != 1) {
+ printk(KERN_WARNING "md: bitmaps only supported for raid1\n");
+ return -EINVAL;
+ }
+ mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
+ }
} else if (mddev->pers == NULL) {
/* Insist of good event counter while assembling */
__u64 ev1 = le64_to_cpu(sb->events);
@@ -960,6 +983,11 @@
else
sb->resync_offset = cpu_to_le64(0);
+ if (mddev->bitmap && mddev->bitmap_file == NULL) {
+ sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
+ sb->feature_map = cpu_to_le32(1);
+ }
+
max_dev = 0;
ITERATE_RDEV(mddev,rdev2,tmp)
if (rdev2->desc_nr+1 > max_dev)
@@ -2406,7 +2434,8 @@
mdname(mddev));
fput(mddev->bitmap_file);
mddev->bitmap_file = NULL;
- }
+ } else
+ mddev->bitmap_offset = 0; /* file overrides offset */
return err;
}
@@ -3774,6 +3803,13 @@
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
if (!spares)
set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
+ if (spares && mddev->bitmap && ! mddev->bitmap->file) {
+ /* We are adding a device or devices to an array
+ * which has the bitmap stored on all devices.
+ * So make sure all bitmap pages get written
+ */
+ bitmap_write_all(mddev->bitmap);
+ }
mddev->sync_thread = md_register_thread(md_do_sync,
mddev,
"%s_resync");