tree 926786cf57b375e5ef1f865427c910c3d4bdfc7a
parent f2b1c41cf94d7f839fe9ede5f3ead92698a93fb3
author Yan Zheng <zheng.yan@oracle.com> 1226320483 -0500
committer Chris Mason <chris.mason@oracle.com> 1226320483 -0500

Btrfs: Fix csum error for compressed data

The decompress code doesn't take the logical offset in extent
pointer into account. If the logical offset isn't zero, data
will be decompressed into wrong pages.

The solution used here is to record the starting offset of the extent
in the file separately from the logical start of the extent_map struct.
This allows us to avoid problems inserting overlapping extents.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>