Ever since the addition of multipage bio_vecs BIO_MAX_PAGES has been
horribly confusingly misnamed. Rename it to BIO_MAX_VECS to stop
confusing users of the bio API.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210311110137.1132391-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It's often inconvenient to use BIO_MAX_PAGES due to min() requiring the
sign to be the same. Introduce bio_max_segs() and change BIO_MAX_PAGES to
be unsigned to make it easier for the users.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Just like what we have to get the passthru ctrl from the req, add an
helper to get the subsystem associated with the nvmet_req() instead
of open coding the chain of structures.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In the NVMeOF block device backend, file backend, and passthru backend
we reject and report the commands if opcode is not handled.
Use the previously introduced helper in the passthru backend to make the
error message uniform.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In nvmet_passthru_execute_cmd() which is a high frequency function
it uses bio_alloc() which leads to memory allocation from the fs pool
for each I/O.
For NVMeoF nvmet_req we already have inline_bvec allocated as a part of
request allocation that can be used with preallocated bio when we
already know the size of request before bio allocation with bio_alloc(),
which we already do.
Introduce a bio member for the nvmet_req passthru anon union. In the
fast path, check if we can get away with inline bvec and bio from
nvmet_req with bio_init() call before actually allocating from the
bio_alloc().
This will be useful to avoid any new memory allocation under high
memory pressure situation and get rid of any extra work of
allocation (bio_alloc()) vs initialization (bio_init()) when
transfer len is < NVMET_MAX_INLINE_DATA_LEN that user can configure at
compile time.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The function blk_rq_append_bio() is a genereric API written for all
types driver (having bounce buffers) and different context (where
request is already having a bio i.e. rq->bio != NULL).
It does mainly three things: calculating the segments, bounce queue and
if req->bio == NULL call blk_rq_bio_prep() or handle low level merge()
case.
The NVMe PCIe and fabrics transports currently does not use queue
bounce mechanism. In order to find this for each request processing
in the passthru blk_rq_append_bio() does extra work in the fast path
for each request.
When I ran I/Os with different block sizes on the passthru controller
I found that we can reuse the req->sg_cnt instead of iterating over the
bvecs to find out nr_segs in blk_rq_append_bio(). This calculation in
blk_rq_append_bio() is a duplication of work given that we have the
value in req->sg_cnt. (correct me here if I'm wrong).
With NVMe passthru request based driver we allocate fresh request each
time, so every call to blk_rq_append_bio() rq->bio will be NULL i.e.
we don't really need the second condition in the blk_rq_append_bio()
and the resulting error condition in the caller of blk_rq_append_bio().
So for NVMeOF passthru driver recalculating the segments, bounce check
and ll_back_merge code is not needed such that we can get away with the
minimal version of the blk_rq_append_bio() which removes the error check
in the fast path along with extra variable in nvmet_passthru_map_sg().
This patch updates the nvmet_passthru_map_sg() such that it does only
appending the bio to the request in the context of the NVMeOF Passthru
driver. Following are perf numbers :-
With current implementation (blk_rq_append_bio()) :-
----------------------------------------------------
+ 5.80% 0.02% kworker/0:2-mm_ [nvmet] [k] nvmet_passthru_execute_cmd
+ 5.44% 0.01% kworker/0:2-mm_ [nvmet] [k] nvmet_passthru_execute_cmd
+ 4.88% 0.00% kworker/0:2-mm_ [nvmet] [k] nvmet_passthru_execute_cmd
+ 5.44% 0.01% kworker/0:2-mm_ [nvmet] [k] nvmet_passthru_execute_cmd
+ 4.86% 0.01% kworker/0:2-mm_ [nvmet] [k] nvmet_passthru_execute_cmd
+ 5.17% 0.00% kworker/0:2-eve [nvmet] [k] nvmet_passthru_execute_cmd
With this patch using blk_rq_bio_prep() :-
----------------------------------------------------
+ 3.14% 0.02% kworker/0:2-eve [nvmet] [k] nvmet_passthru_execute_cmd
+ 3.26% 0.01% kworker/0:2-eve [nvmet] [k] nvmet_passthru_execute_cmd
+ 5.37% 0.01% kworker/0:2-mm_ [nvmet] [k] nvmet_passthru_execute_cmd
+ 5.18% 0.02% kworker/0:2-eve [nvmet] [k] nvmet_passthru_execute_cmd
+ 4.84% 0.02% kworker/0:2-mm_ [nvmet] [k] nvmet_passthru_execute_cmd
+ 4.87% 0.01% kworker/0:2-mm_ [nvmet] [k] nvmet_passthru_execute_cmd
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
For passthru commands setting op_flags has no meaning. Remove the code
that sets the op flags in nvmet_passthru_map_sg().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Right now nvme_alloc_request() allocates a request from block layer
based on the value of the qid. When qid set to NVME_QID_ANY it used
blk_mq_alloc_request() else blk_mq_alloc_request_hctx().
The function nvme_alloc_request() is called from different context, The
only place where it uses non NVME_QID_ANY value is for fabrics connect
commands :-
nvme_submit_sync_cmd() NVME_QID_ANY
nvme_features() NVME_QID_ANY
nvme_sec_submit() NVME_QID_ANY
nvmf_reg_read32() NVME_QID_ANY
nvmf_reg_read64() NVME_QID_ANY
nvmf_reg_write32() NVME_QID_ANY
nvmf_connect_admin_queue() NVME_QID_ANY
nvme_submit_user_cmd() NVME_QID_ANY
nvme_alloc_request()
nvme_keep_alive() NVME_QID_ANY
nvme_alloc_request()
nvme_timeout() NVME_QID_ANY
nvme_alloc_request()
nvme_delete_queue() NVME_QID_ANY
nvme_alloc_request()
nvmet_passthru_execute_cmd() NVME_QID_ANY
nvme_alloc_request()
nvmf_connect_io_queue() QID
__nvme_submit_sync_cmd()
nvme_alloc_request()
With passthru nvme_alloc_request() now falls into the I/O fast path such
that blk_mq_alloc_request_hctx() is never gets called and that adds
additional branch check in fast path.
Split the nvme_alloc_request() into nvme_alloc_request() and
nvme_alloc_request_qid().
Replace each call of the nvme_alloc_request() with NVME_QID_ANY param
with a call to newly added nvme_alloc_request() without NVME_QID_ANY.
Replace a call to nvme_alloc_request() with QID param with a call to
newly added nvme_alloc_request() and nvme_alloc_request_qid()
based on the qid value set in the __nvme_submit_sync_cmd().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
NVMeOF controller in the passsthru mode is capable of handling wide set
of I/O commands including vender specific passhtru io comands.
The vendor specific I/O commands are used to read the large drive
logs and can take longer than default NVMe commands, i.e. for
passthru requests the timeout value may differ from the passthru
controller's default timeout values (nvme-core:io_timeout).
Add a configfs attribute so that user can set the io timeout values.
In case if this configfs value is not set nvme_alloc_request() will set
the NVME_IO_TIMEOUT value when request queuedata is NULL.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
NVMeOF controller in the passsthru mode is capable of handling wide set
of admin commands including vender specific passhtru admin comands.
The vendor specific admin commands are used to read the large drive
logs and can take longer than default NVMe commands, i.e. for
passthru requests the timeout value may differ from the passthru
controller's default timeout values (nvme-core:admin_timeout).
Add a configfs attribute so that user can set the admin timeout values.
In case if this configfs value is not set nvme_alloc_request() will set
the ADMIN_TIMEOUT value when request queuedata is NULL.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
By default, we set the passthru request allocation flag such that it
returns the error in the following code path and we fail the I/O when
BLK_MQ_REQ_NOWAIT is used for request allocation :-
nvme_alloc_request()
blk_mq_alloc_request()
blk_mq_queue_enter()
if (flag & BLK_MQ_REQ_NOWAIT)
return -EBUSY; <-- return if busy.
On some controllers using BLK_MQ_REQ_NOWAIT ends up in I/O error where
the controller is perfectly healthy and not in a degraded state.
Block layer request allocation does allow us to wait instead of
immediately returning the error when we BLK_MQ_REQ_NOWAIT flag is not
used. This has shown to fix the I/O error problem reported under
heavy random write workload.
Remove the BLK_MQ_REQ_NOWAIT parameter for passthru request allocation
which resolves this issue.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Clean up some confusing elements of nvmet_passthru_map_sg() by returning
early if the request is greater than the maximum bio size. This allows
us to drop the sg_cnt variable.
This should not result in any functional change but makes the code
clearer and more understandable. The original code allocated a truncated
bio then would return EINVAL when bio_add_pc_page() filled that bio. The
new code just returns EINVAL early if this would happen.
Fixes: c1fef73f79 ("nvmet: add passthru code to process commands")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Suggested-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
nvmet_passthru_map_sg() only supports mapping a single BIO, not a chain
so the effective maximum transfer should also be limitted by
BIO_MAX_PAGES (presently this works out to 1MB).
For PCI passthru devices the max_sectors would typically be more
limitting than BIO_MAX_PAGES, but this may not be true for all passthru
devices.
Fixes: c1fef73f79 ("nvmet: add passthru code to process commands")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In the default passthru implementation NVMeOF target passthru ctrl is
not capable of handling Zoned Namespaces (ZNS).
Update the nvmet_parse_pasthru_admin_cmd() to allow
NVME_ID_CNS_CS_CTRL/NVME_CIS_ZNS and NVME_ID_CNS_CS_NS/NVME_CIS_ZNS.
With this addition NVMeOF Passthru allows Zoned Namespaces.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Lift opening the file open/close code from nvme_ctrl_get_by_path into
the caller, just keeping a simple nvme_ctrl_from_file() helper.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[hch: refactored a bit, split the bug fixes into a separate prep patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Grab a reference to the transport driver to ensure it can't be unloaded
while a passthrough controller is active.
Fixes: c1fef73f79 ("nvmet: add passthru code to process commands")
Reported-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Instead of calling blk_put_request() which calls blk_mq_free_request(),
call blk_mq_free_request() directly for NVMeOF passthru. This is to
mainly avoid an extra function call in the completion path
nvmet_passthru_req_done().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In the current implementation before submitting the passthru cmd we
may come across error e.g. getting ns from passthru controller,
allocating a request from passthru controller, etc. For all the failure
cases it only uses single goto label fail_out.
In the target code, we follow the pattern to have a separate label for
each error out the case when setting up multiple things before the actual
action.
This patch follows the same pattern and renames generic fail_out label
to out_put_ns and updates the error out cases in the
nvmet_passthru_execute_cmd() where it is needed.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Any command with a non-SGL flag set (like fuse flags) should be
rejected.
Fixes: c1fef73f79 ("nvmet: add passthru code to process commands")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch adds helper functions which are used in the NVMeOF configfs
when the user is configuring the passthru subsystem. Here we ensure
that only one subsys is assigned to each nvme_ctrl by using an xarray
on the cntlid.
The subsystem's version number is overridden by the passed through
controller's version. However, if that version is less than 1.2.1,
then we bump the advertised version to that and print a warning
in dmesg.
Based-on-a-patch-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Add passthru command handling capability for the NVMeOF target and
export passthru APIs which are used to integrate passthru
code with nvmet-core.
The new file passthru.c handles passthru cmd parsing and execution.
In the passthru mode, we create a block layer request from the nvmet
request and map the data on to the block layer request.
Admin commands and features are on an allow list as there are a number
of each that don't make too much sense with passthrough. We use an
allow list such that new commands can be considered before being blindly
passed through. In both cases, vendor specific commands are always
allowed.
We also reject reservation IO commands as the underlying device cannot
differentiate between multiple hosts behind a fabric.
Based-on-a-patch-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Christoph Hellwig