tree 3d2a46624bf6cf1ea1645cc8dad975af858dc114
parent 3fd0a5585eb98e074fb9934549c8d85c49756c0d
author Josef Bacik <josef@redhat.com> 1274626854 -0400
committer Chris Mason <chris.mason@oracle.com> 1274798095 -0400

fs: allow short direct-io reads to be completed via buffered IO

This is similar to what already happens in the write case.  If we have a short
read while doing O_DIRECT, instead of just returning, fallthrough and try to
read the rest via buffered IO.  BTRFS needs this because if we encounter a
compressed or inline extent during DIO, we need to fallback on buffered.  If the
extent is compressed we need to read the entire thing into memory and
de-compress it into the users pages.  I have tested this with fsx and everything
works great.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>