linux/drivers/nvme/target
Sagi Grimberg 8407879c4e nvmet-rdma: fix possible bogus dereference under heavy load
Currently we always repost the recv buffer before we send a response
capsule back to the host. Since ordering is not guaranteed for send
and recv completions, it is posible that we will receive a new request
from the host before we got a send completion for the response capsule.

Today, we pre-allocate 2x rsps the length of the queue, but in reality,
under heavy load there is nothing that is really preventing the gap to
expand until we exhaust all our rsps.

To fix this, if we don't have any pre-allocated rsps left, we dynamically
allocate a rsp and make sure to free it when we are done. If under memory
pressure we fail to allocate a rsp, we silently drop the command and
wait for the host to retry.

Reported-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
[hch: dropped a superflous assignment]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-09-05 12:18:01 -07:00
..
admin-cmd.c nvmet: add ns write protect support 2018-08-08 12:00:53 +02:00
configfs.c for-4.19/block-20180812 2018-08-14 10:23:25 -07:00
core.c nvmet: free workqueue object if module init fails 2018-08-28 08:40:44 +02:00
discovery.c nvmet-rdma: support max(16KB, PAGE_SIZE) inline data 2018-07-23 09:35:16 +02:00
fabrics-cmd.c nvmet: remove duplicate NULL initialization for req->ns 2018-05-25 16:50:12 +02:00
fc.c nvmet-fc: fix target sgl list on large transfers 2018-07-24 13:44:09 +02:00
fcloop.c nvme-fcloop: Fix dropped LS's to removed target port 2018-08-28 08:40:43 +02:00
io-cmd-bdev.c nvmet: add ns write protect support 2018-08-08 12:00:53 +02:00
io-cmd-file.c nvmet: add ns write protect support 2018-08-08 12:00:53 +02:00
Kconfig nvmet-rdma: depend on INFINIBAND_ADDR_TRANS 2018-04-27 11:15:43 -04:00
loop.c for-4.19/block-20180812 2018-08-14 10:23:25 -07:00
Makefile nvmet: add simple file backed ns support 2018-05-25 16:50:12 +02:00
nvmet.h nvmet: add ns write protect support 2018-08-08 12:00:53 +02:00
rdma.c nvmet-rdma: fix possible bogus dereference under heavy load 2018-09-05 12:18:01 -07:00