On 04/07/2016 04:37 PM, Nicholas A. Bellinger wrote:
On Thu, 2016-04-07 at 15:55 -0700, Bart Van Assche wrote:
That patch causes the ib_srpt driver to crash as soon as the first
SCSI command is received. This means that that patch was untested.
Hence revert it. The shortcomings of that patch are as follows:
- It makes the ib_srpt driver use I/O contexts allocated by
transport_alloc_session_tags() but it does not initialize these
I/O contexts properly. All the initializations performed by
srpt_alloc_ioctx() are skipped.
- It swaps the order of the send ioctx allocation and the transition
to RTR mode which is wrong.
- The amount of memory that is needed for I/O contexts is doubled.
- srpt_rdma_ch.free_list is no longer used but is not removed.
Revert commit 0fd10721fe36 and thereby fix the following kernel crash:
kernel BUG at drivers/infiniband/ulp/srpt/ib_srpt.c:1439!
invalid opcode: 0000 [#1] SMP
Workqueue: target_completion target_complete_ok_work [target_core_mod]
RIP: 0010:[<ffffffffa052ef37>] [<ffffffffa052ef37>] srpt_queue_response+0x437/0x4a0 [ib_srpt]
Call Trace:
[<ffffffffa052f009>] srpt_queue_data_in+0x9/0x10 [ib_srpt]
[<ffffffffa04f1ee2>] target_complete_ok_work+0x152/0x2b0 [target_core_mod]
[<ffffffff81071ea7>] process_one_work+0x197/0x480
[<ffffffff810721d9>] worker_thread+0x49/0x490
[<ffffffff8107878a>] kthread+0xea/0x100
[<ffffffff8159b172>] ret_from_fork+0x22/0x40
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
I've already asked you not to revert the patch [ ... ]
But why not to revert that patch? Your patch was completely untested and
makes the ib_srpt driver unusable. I think the regular approach for such
patches is to revert them and to rework these in a later kernel version.
Linus, please let me know if you disagree.
Bart.
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