tree c810b72c091b8bf596a21ee4d56c830b9d0c4c50
parent 9aaab0589baa61d637a52badddbff2d74f35a955
author Leonard Michlmayr <leonard.michlmayr@gmail.com> 1267740448 -0500
committer Theodore Ts'o <tytso@mit.edu> 1267740448 -0500

ext4: correctly calculate number of blocks for fiemap

ext4_fiemap() rounds the length of the requested range down to
blocksize, which is is not the true number of blocks that cover the
requested region.  This problem is especially impressive if the user
requests only the first byte of a file: not a single extent will be
reported.

We fix this by calculating the last block of the region and then
subtract to find the number of blocks in the extents.

Signed-off-by: Leonard Michlmayr <leonard.michlmayr@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>