tree d0f7eb47da8263f2ac35554ead88a8cf70cd99cf
parent ad1857a0e0cb29313efae3bb69c913b2c3c833a1
author Lukas Czerner <lczerner@redhat.com> 1290425357 +0100
committer Jan Kara <jack@suse.cz> 1294682638 +0100

ext3: Add batched discard support for ext3

Walk through allocation groups and trim all free extents. It can be
invoked through FITRIM ioctl on the file system. The main idea is to
provide a way to trim the whole file system if needed, since some SSD's
may suffer from performance loss after the whole device was filled (it
does not mean that fs is full!).

It search for free extents in allocation groups specified by Byte range
start -> start+len. When the free extent is within this range, blocks are
marked as used and then trimmed. Afterwards these blocks are marked as
free in per-group bitmap.

[JK: Fixed up error handling and trimming of a single group]

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>