linux/block
David Woodhouse fb2dce862d Add 'discard' request handling
Some block devices benefit from a hint that they can forget the contents
of certain sectors. Add basic support for this to the block core, along
with a 'blkdev_issue_discard()' helper function which issues such
requests.

The caller doesn't get to provide an end_io functio, since
blkdev_issue_discard() will automatically split the request up into
multiple bios if appropriate. Neither does the function wait for
completion -- it's expected that callers won't care about when, or even
_if_, the request completes. It's only a hint to the device anyway. By
definition, the file system doesn't _care_ about these sectors any more.

[With feedback from OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> and
Jens Axboe <jens.axboe@oracle.com]

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:01 +02:00
..
as-iosched.c Use WARN() in block/ 2008-07-26 12:00:07 -07:00
blk-barrier.c Add 'discard' request handling 2008-10-09 08:56:01 +02:00
blk-core.c Add 'discard' request handling 2008-10-09 08:56:01 +02:00
blk-exec.c block: unexport blk_end_sync_rq 2008-07-15 21:21:45 +02:00
blk-integrity.c block: integrity flags can't use bit ops on unsigned short 2008-07-03 13:21:15 +02:00
blk-ioc.c cfq-iosched: fix RCU race in the cfq io_context destructor handling 2008-05-07 09:28:57 +02:00
blk-map.c block/blk-map.c: use the new object_is_on_stack() helper 2008-07-26 12:00:02 -07:00
blk-merge.c block: Block layer data integrity support 2008-07-03 13:21:13 +02:00
blk-settings.c Add 'discard' request handling 2008-10-09 08:56:01 +02:00
blk-sysfs.c block: sysfs store function needs to grab queue_lock and use queue_flag_*() 2008-05-07 09:09:39 +02:00
blk-tag.c block: remove unused ->busy part of the block queue tag map 2008-08-27 09:50:19 +02:00
blk.h block: Block layer data integrity support 2008-07-03 13:21:13 +02:00
blktrace.c Added in user-injected messages into blk traces 2008-07-03 13:21:12 +02:00
bsg.c block: move cmdfilter from gendisk to request_queue 2008-08-27 09:50:19 +02:00
cfq-iosched.c cfq-iosched: get rid of enable_idle being unused warning 2008-07-03 13:21:14 +02:00
cmd-filter.c block: disable sysfs parts of the disk command filter 2008-09-11 14:20:23 +02:00
compat_ioctl.c Fix misuses of bdevname() 2008-05-13 08:02:26 -07:00
deadline-iosched.c block: let elv_register() return void 2007-12-18 08:29:28 +01:00
elevator.c block: request_module(): use format string 2008-07-03 13:21:15 +02:00
genhd.c block: restore original behavior of /proc/partition when there's no partition 2008-09-01 08:55:10 +02:00
ioctl.c block/ioctl.c and fs/partition/check.c: check value returned by add_partition() 2008-07-25 10:53:44 -07:00
Kconfig block: Block layer data integrity support 2008-07-03 13:21:13 +02:00
Kconfig.iosched update I/O sched Kconfig help texts - CFQ is now default, not AS. 2007-02-17 20:08:22 +01:00
Makefile allow userspace to modify scsi command filter on per device basis 2008-07-03 13:21:14 +02:00
noop-iosched.c block: let elv_register() return void 2007-12-18 08:29:28 +01:00
scsi_ioctl.c SG_IO block filter whitelist missing MMC SET READ AHEAD command 2008-10-09 08:56:00 +02:00