btrfs: btrfs_rm_device() should zero mirror SB as well

This fix will ensure all SB copies on the disk is zeroed
when the disk is intentionally removed. This helps to
better manage disks in the user land.

This version of patch also merges the Zach patch as below.

 btrfs: don't double brelse on device rm

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
Anand Jain 2014-04-06 12:59:07 +08:00 committed by Chris Mason
parent 27cdeb7096
commit 4d90d28b1c

View File

@ -1710,12 +1710,43 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
* remove it from the devices list and zero out the old super
*/
if (clear_super && disk_super) {
u64 bytenr;
int i;
/* make sure this device isn't detected as part of
* the FS anymore
*/
memset(&disk_super->magic, 0, sizeof(disk_super->magic));
set_buffer_dirty(bh);
sync_dirty_buffer(bh);
/* clear the mirror copies of super block on the disk
* being removed, 0th copy is been taken care above and
* the below would take of the rest
*/
for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE >=
i_size_read(bdev->bd_inode))
break;
brelse(bh);
bh = __bread(bdev, bytenr / 4096,
BTRFS_SUPER_INFO_SIZE);
if (!bh)
continue;
disk_super = (struct btrfs_super_block *)bh->b_data;
if (btrfs_super_bytenr(disk_super) != bytenr ||
btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
continue;
}
memset(&disk_super->magic, 0,
sizeof(disk_super->magic));
set_buffer_dirty(bh);
sync_dirty_buffer(bh);
}
}
ret = 0;