Commit ff61d17c authored Jul 24, 2014 by Miao Xie Committed by Chris Mason Aug 19, 2014

Btrfs: Fix the problem that the replace destroys the seed filesystem



The seed filesystem was destroyed by the device replace, the reproduce
method is:
 # mkfs.btrfs -f <dev0>
 # btrfstune -S 1 <dev0>
 # mount <dev0> <mnt>
 # btrfs device add <dev1> <mnt>
 # umount <mnt>
 # mount <dev1> <mnt>
 # btrfs replace start -f <dev0> <dev2> <mnt>
 # umount <mnt>
 # mount <dev0> <mnt>

It is because we erase the super block on the seed device. It is wrong,
we should not change anything on the seed device.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

parent 2c91943b

fs/btrfs/volumes.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -1848,7 +1848,11 @@ void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
		if (srcdev->bdev) {
		fs_info->fs_devices->open_devices--;

		/* zero out the old super */
		/*
		* zero out the old super if it is not writable
		* (e.g. seed device)
		*/
		if (srcdev->writeable)
		btrfs_scratch_superblock(srcdev);
		}

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