tree 0cecb2acc903154e25abb23e8f345f301fcd1ef5
parent effc6cc8828257c32c37635e737f14fd6e19ecd7
author Roland Dreier <roland@purestorage.com> 1329178697 -0800
committer Nicholas Bellinger <nab@linux-iscsi.org> 1330209469 -0800

target: Untangle front-end and back-end meanings of max_sectors attribute

se_dev_attrib.max_sectors currently has two independent meanings:

 - It is reported in the block limits VPD page as the maximum transfer
   length, ie the largest IO that the front-end (fabric) can handle.
   Also the target core doesn't enforce this maximum transfer length.

 - It is used to hold the size of the largest IO that the back-end can
   handle, so we know when to split SCSI commands into multiple tasks.

Fix this by adding a new se_dev_attrib.fabric_max_sectors to hold the
maximum transfer length, and checking incoming IOs against that limit.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>