tree f735cb5f4dbf4b0aa750572dbf1efac69ce2d4af
parent bad54831968a8429b08e34faf33178c21ac6bba0
author Lukas Czerner <lczerner@redhat.com> 1369711955 -0400
committer Theodore Ts'o <tytso@mit.edu> 1369711955 -0400

mm: teach truncate_inode_pages_range() to handle non page aligned ranges

This commit changes truncate_inode_pages_range() so it can handle non
page aligned regions of the truncate. Currently we can hit BUG_ON when
the end of the range is not page aligned, but we can handle unaligned
start of the range.

Being able to handle non page aligned regions of the page can help file
system punch_hole implementations and save some work, because once we're
holding the page we might as well deal with it right away.

In previous commits we've changed ->invalidatepage() prototype to accept
'length' argument to be able to specify range to invalidate. No we can
use that new ability in truncate_inode_pages_range().

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>