From 4d90d28b1c5c5ab6292c0888dc1ebdfc3023f877 Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Sun, 6 Apr 2014 12:59:07 +0800 Subject: [PATCH] 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 Signed-off-by: Zach Brown Signed-off-by: Chris Mason --- fs/btrfs/volumes.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 8113f4567084..ee71622088f9 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -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; -- 2.20.1