mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-05 10:31:46 +09:00
ba388d4e9a
[ Upstream commit c03fd85de2 ]
nvme_clear_request() has a check for flag REQ_DONTPREP and it is called
from nvme_init_request() and nvme_setuo_cmd().
The function nvme_init_request() is called from nvme_alloc_request()
and nvme_alloc_request_qid(). From these two callers new request is
allocated everytime. For newly allocated request RQF_DONTPREP is never
set. Since after getting a tag, block layer sets the req->rq_flags == 0
and never sets the REQ_DONTPREP when returning the request :-
nvme_alloc_request()
blk_mq_alloc_request()
blk_mq_rq_ctx_init()
rq->rq_flags = 0 <----
nvme_alloc_request_qid()
blk_mq_alloc_request_hctx()
blk_mq_rq_ctx_init()
rq->rq_flags = 0 <----
The block layer does set req->rq_flags but REQ_DONTPREP is not one of
them and that is set by the driver.
That means we can unconditinally set the REQ_DONTPREP value to the
rq->rq_flags when nvme_init_request()->nvme_clear_request() is called
from above two callers.
Move the check for REQ_DONTPREP from nvme_clear_nvme_request() into
nvme_setup_cmd().
This is needed since nvme_alloc_request() now gets called from fast
path when NVMeOF target is configured with passthru backend to avoid
unnecessary checks in the fast path.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.