linux/drivers/target
Christoph Hellwig bebe2fdc17 target: stop splitting commands into multiple tasks
From hch:

The high-performance backends (iblock and rd) support tasks of unlimited
size.  With that there is no reason to keep a complex infrastructure for
splitting up commands in place.  Stop doing so and only submit a single
task per data direction.  Once this is in place we can slowly remove fields
from the task that duplicate things in the command, or move other fields
into the command.

From nab:

The benefit to IBLOCK performance by removing the additional
fast-path allocation overhead + SGL mapping to se_task->task_sg[] is now
greater than transparently supporting an received CDB I/O length that
exceeds what is allowed by backend pSCSI LLD hardware max_sectors, that
was originally supported for all backend export cases.

This change may effect some users of pSCSI users on legacy hardware, but
I think most folks are now using TYPE_DISK struct scsi_device export
with IBLOCK.  The only other place where this may can issues that cannot
be resolved with IBLOCK TYPE_DISK is using TYPE_ROM, TYPE_TAPE or other
pSCSI non TYPE_DISK export with an SCSI LLDs using a smaller
max_sectors.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2012-04-14 17:40:31 -07:00
..
iscsi Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2012-03-22 12:38:04 -07:00
loopback loopback: Fix transport_generic_allocate_tasks error handling 2012-03-17 18:07:27 -07:00
tcm_fc tcm_fc: Do not free tpg structure during wq allocation failure 2012-04-06 18:57:05 -07:00
Kconfig iscsi-target: Add iSCSI fabric support for target v4.1 2011-07-26 09:16:43 +00:00
Makefile target: remove the ->transport_split_cdb callback in se_cmd 2011-10-24 03:21:15 +00:00
target_core_alua.c target: Fix 16-bit target ports for SET TARGET PORT GROUPS emulation 2012-02-25 14:37:50 -08:00
target_core_alua.h target: pass the se_task to the CDB emulation callback 2011-11-04 08:00:17 +00:00
target_core_cdb.c target: stop splitting commands into multiple tasks 2012-04-14 17:40:31 -07:00
target_core_configfs.c target: remove obvious warnings 2012-03-15 19:16:09 -07:00
target_core_device.c target: Remove obsolete DF_READ_ONLY usage 2012-04-14 16:04:58 -07:00
target_core_fabric_configfs.c target: Use array_zalloc for device_list 2012-03-15 19:15:51 -07:00
target_core_fabric_lib.c target: remove useless casts 2011-12-14 11:28:07 +00:00
target_core_file.c target: remove useless casts 2011-12-14 11:28:07 +00:00
target_core_file.h target: make the ->get_cdb method optional 2011-10-24 03:21:11 +00:00
target_core_hba.c target: header reshuffle, part2 2011-12-14 11:26:05 +00:00
target_core_iblock.c target: increase iblock task sizes 2012-02-25 14:37:46 -08:00
target_core_iblock.h target: increase iblock task sizes 2012-02-25 14:37:46 -08:00
target_core_internal.h target: Untangle front-end and back-end meanings of max_sectors attribute 2012-02-25 14:37:49 -08:00
target_core_pr.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2012-03-22 12:38:04 -07:00
target_core_pr.h target: Move core_scsi3_check_cdb_abort_and_preempt 2011-12-14 11:27:34 +00:00
target_core_pscsi.c target/pscsi: fix PHV_VIRUTAL_HOST_ID typo 2012-02-25 14:37:50 -08:00
target_core_pscsi.h target/pscsi: fix PHV_VIRUTAL_HOST_ID typo 2012-02-25 14:37:50 -08:00
target_core_rd.c target: don't limit transfer sizes for the ramdisk backend 2012-04-14 17:40:30 -07:00
target_core_rd.h target: don't limit transfer sizes for the ramdisk backend 2012-04-14 17:40:30 -07:00
target_core_stat.c target: remove obvious warnings 2012-03-15 19:16:09 -07:00
target_core_tmr.c target: Add TMR_ABORT_TASK task management support 2012-02-25 14:37:49 -08:00
target_core_tpg.c target: Remove obsolete DF_READ_ONLY usage 2012-04-14 16:04:58 -07:00
target_core_transport.c target: stop splitting commands into multiple tasks 2012-04-14 17:40:31 -07:00
target_core_ua.c target: Use array_zalloc for device_list 2012-03-15 19:15:51 -07:00
target_core_ua.h