According to the bytenr of the extent buffer record, we can calculate the index
of the stripes, and we also know which device and where we read out the extent
buffer record, that means we can know the relationship between the device extent
and the stripes in the chunk, by this relationship, we can recover the raid0/radi10/
raid5/raid6 metadata chunk.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Add chunk rebuild for RAID1/SINGLE/DUP to chunk-recover command.
Before this patch chunk-recover can only scan and reuse the old chunk
data to recover. With this patch, chunk-recover can use the reference
between chunk/block group/dev extent to rebuild the whole chunk tree
even when old chunks are not available.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Add chunk-recover program to check or rebuild chunk tree when the system
chunk array or chunk tree is broken.
Due to the importance of the system chunk array and chunk tree, if one of
them is broken, the whole btrfs will be broken even other data are OK.
But we have some hint(fsid, checksum...) to salvage the old metadata.
So this function will first scan the whole file system and collect the
needed data(chunk/block group/dev extent), and check for the references
between them. If the references are OK, the chunk tree can be rebuilt and
luckily the file system will be mountable.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Miao Xie