ids_inflight is used to track the inflight IOs. But the use of atomic_t
variable can cause performance drops and can also become a performance
bottleneck.
This commit replaces the use of atomic_t with a percpu_ref structure. The
advantage it offers is, it doesn't check if the reference has fallen to 0,
until the user explicitly signals it to; and that is done by the
percpu_ref_kill() function call. After that, the percpu_ref structure
behaves like an atomic_t and for every put call, checks whether the
reference has fallen to 0 or not.
rtrs_srv_stats_rdma_to_str shows the count of ids_inflight as 0
for user-mode tools not to be confused.
Fixes: 9cb8374804 ("RDMA/rtrs: server: main functionality")
Link: https://lore.kernel.org/r/20210528113018.52290-14-jinpu.wang@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
When get_next_path_min_inflight is called to select the next path, it
iterates over the list of available rtrs_clt_sess (paths). It then reads
the number of inflight IOs for that path to select one which has the least
inflight IO.
But it may so happen that rtrs_clt_sess (path) is no longer in the
connected state because closing or error recovery paths can change the status
of the rtrs_clt_Sess.
For example, the client sent the heart-beat and did not get the
response, it would change the session status and stop IO processing.
The added checking of this patch can prevent accessing the broken path
and generating duplicated error messages.
It is ok if the status is changed after checking the status because
the error recovery path does not free memory and only tries to
reconnection. And also it is ok if the session is closed after checking
the status because closing the session changes the session status and
flush all IO beforing free memory. If the session is being accessed for
IO processing, the closing session will wait.
Fixes: 6a98d71dae ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20210528113018.52290-13-jinpu.wang@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Define .init_cmd_priv and .exit_cmd_priv callback functions in struct
scsi_host_template. Set .cmd_size such that the SCSI core allocates
per-command private data. Use scsi_cmd_priv() to access that private
data. Remove the req_ring pointer from struct srp_rdma_ch since it is no
longer necessary. Convert srp_alloc_req_data() and srp_free_req_data()
into functions that initialize one instance of the SRP-private command
data. This is a micro-optimization since this patch removes several
pointer dereferences from the hot path.
Note: due to commit e73a5e8e80 ("scsi: core: Only return started
requests from scsi_host_find_tag()"), it is no longer necessary to protect
the completion path against duplicate responses.
Link: https://lore.kernel.org/r/20210524041211.9480-6-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Variable 'ret' is set to -ENOMEM but this value is never read as it is
overwritten with a new value later on, hence it is a redundant assignment
and can be removed
In 'commit b79fafac70 ("target: make queue_tm_rsp() return void")'
srpt_queue_response() has been changed to return void, so after "goto
out", there is no need to return ret.
Clean up the following clang-analyzer warning:
drivers/infiniband/ulp/srpt/ib_srpt.c:2860:3: warning: Value stored to
'ret' is never read [clang-analyzer-deadcode.DeadStores]
Fixes: b99f8e4d7b ("IB/srpt: convert to the generic RDMA READ/WRITE API")
Link: https://lore.kernel.org/r/1620296105-121964-1-git-send-email-yang.lee@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Pull block fixes from Jens Axboe:
- dasd spelling fixes (Bhaskar)
- Limit bio max size on multi-page bvecs to the hardware limit, to
avoid overly large bio's (and hence latencies). Originally queued for
the merge window, but needed a fix and was dropped from the initial
pull (Changheun)
- NVMe pull request (Christoph):
- reset the bdev to ns head when failover (Daniel Wagner)
- remove unsupported command noise (Keith Busch)
- misc passthrough improvements (Kanchan Joshi)
- fix controller ioctl through ns_head (Minwoo Im)
- fix controller timeouts during reset (Tao Chiu)
- rnbd fixes/cleanups (Gioh, Md, Dima)
- Fix iov_iter re-expansion (yangerkun)
* tag 'block-5.13-2021-05-07' of git://git.kernel.dk/linux-block:
block: reexpand iov_iter after read/write
nvmet: remove unsupported command noise
nvme-multipath: reset bdev to ns head when failover
nvme-pci: fix controller reset hang when racing with nvme_timeout
nvme: move the fabrics queue ready check routines to core
nvme: avoid memset for passthrough requests
nvme: add nvme_get_ns helper
nvme: fix controller ioctl through ns_head
bio: limit bio max size
RDMA/rtrs: fix uninitialized symbol 'cnt'
s390: dasd: Mundane spelling fixes
block/rnbd: Remove all likely and unlikely
block/rnbd-clt: Check the return value of the function rtrs_clt_query
block/rnbd: Fix style issues
block/rnbd-clt: Change queue_depth type in rnbd_clt_session to size_t
Pull rdma updates from Jason Gunthorpe:
"This is significantly bug fixes and general cleanups. The noteworthy
new features are fairly small:
- XRC support for HNS and improves RQ operations
- Bug fixes and updates for hns, mlx5, bnxt_re, hfi1, i40iw, rxe, siw
and qib
- Quite a few general cleanups on spelling, error handling, static
checker detections, etc
- Increase the number of device ports supported beyond 255. High port
count software switches now exist
- Several bug fixes for rtrs
- mlx5 Device Memory support for host controlled atomics
- Report SRQ tables through to rdma-tool"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (145 commits)
IB/qib: Remove redundant assignment to ret
RDMA/nldev: Add copy-on-fork attribute to get sys command
RDMA/bnxt_re: Fix a double free in bnxt_qplib_alloc_res
RDMA/siw: Fix a use after free in siw_alloc_mr
IB/hfi1: Remove redundant variable rcd
RDMA/nldev: Add QP numbers to SRQ information
RDMA/nldev: Return SRQ information
RDMA/restrack: Add support to get resource tracking for SRQ
RDMA/nldev: Return context information
RDMA/core: Add CM to restrack after successful attachment to a device
RDMA/cma: Skip device which doesn't support CM
RDMA/rxe: Fix a bug in rxe_fill_ip_info()
RDMA/mlx5: Expose private query port
RDMA/mlx4: Remove an unused variable
RDMA/mlx5: Fix type assignment for ICM DM
IB/mlx5: Set right RoCE l3 type and roce version while deleting GID
RDMA/i40iw: Fix error unwinding when i40iw_hmc_sd_one fails
RDMA/cxgb4: add missing qpid increment
IB/ipoib: Remove unnecessary struct declaration
RDMA/bnxt_re: Get rid of custom module reference counting
...
Pull SCSI updates from James Bottomley:
"This consists of the usual driver updates (ufs, target, tcmu,
smartpqi, lpfc, zfcp, qla2xxx, mpt3sas, pm80xx).
The major core change is using a sbitmap instead of an atomic for
queue tracking"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (412 commits)
scsi: target: tcm_fc: Fix a kernel-doc header
scsi: target: Shorten ALUA error messages
scsi: target: Fix two format specifiers
scsi: target: Compare explicitly with SAM_STAT_GOOD
scsi: sd: Introduce a new local variable in sd_check_events()
scsi: dc395x: Open-code status_byte(u8) calls
scsi: 53c700: Open-code status_byte(u8) calls
scsi: smartpqi: Remove unused functions
scsi: qla4xxx: Remove an unused function
scsi: myrs: Remove unused functions
scsi: myrb: Remove unused functions
scsi: mpt3sas: Fix two kernel-doc headers
scsi: fcoe: Suppress a compiler warning
scsi: libfc: Fix a format specifier
scsi: aacraid: Remove an unused function
scsi: core: Introduce enum scsi_disposition
scsi: core: Modify the scsi_send_eh_cmnd() return value for the SDEV_BLOCK case
scsi: core: Rename scsi_softirq_done() into scsi_complete()
scsi: core: Remove an incorrect comment
scsi: core: Make the scsi_alloc_sgtables() documentation more accurate
...
RNBD can make double-queues for irq-mode and poll-mode.
For example, on 4-CPU system 8 request-queues are created,
4 for irq-mode and 4 for poll-mode.
If the IO has HIPRI flag, the block-layer will call .poll function
of RNBD. Then IO is sent to the poll-mode queue.
Add optional nr_poll_queues argument for map_devices interface.
To support polling of RNBD, RTRS client creates connections
for both of irq-mode and direct-poll-mode.
For example, on 4-CPU system it could've create 5 connections:
con[0] => user message (softirq cq)
con[1:4] => softirq cq
After this patch, it can create 9 connections:
con[0] => user message (softirq cq)
con[1:4] => softirq cq
con[5:8] => DIRECT-POLL cq
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20210419073722.15351-14-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently IPoIB connected mode queries the device to get the pkey table
entry during connection formation. This will increase the time taken to
form the connection, especially when limited pkeys are in use. This gets
worse when multiple connection attempts are done in parallel.
Since ipoib interfaces are locked to a single pkey, use the pkey index
that was determined at link up time instead of searching for anything.
This improved the latency from 500ms to 1ms on an internal setup.
Link: https://lore.kernel.org/r/1618338965-16717-1-git-send-email-manjunath.b.patil@oracle.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Manjunath Patil <manjunath.b.patil@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Client prints only error value and it is not enough for debugging.
1. When client receives an error from server: the client does not only
print the error value but also more information of server connection.
2. When client failes to send IO: the client gets an error from RDMA
layer. It also print more information of server connection.
Link: https://lore.kernel.org/r/20210406123639.202899-2-gi-oh.kim@ionos.com
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
A session can be removed dynamically by sysfs interface "remove_path" that
eventually calls rtrs_clt_remove_path_from_sysfs function. The current
rtrs_clt_remove_path_from_sysfs first removes the sysfs interfaces and
frees sess->stats object. Second it removes the session from the active
list.
Therefore some functions could access non-connected session and access the
freed sess->stats object even-if they check the session status before
accessing the session.
For instance rtrs_clt_request and get_next_path_min_inflight check the
session status and try to send IO to the session. The session status
could be changed when they are trying to send IO but they could not catch
the change and update the statistics information in sess->stats object,
and generate use-after-free problem.
(see: "RDMA/rtrs-clt: Check state of the rtrs_clt_sess before reading its
stats")
This patch changes the rtrs_clt_remove_path_from_sysfs to remove the
session from the active session list and then destroy the sysfs
interfaces.
Each function still should check the session status because closing or
error recovery paths can change the status.
Fixes: 6a98d71dae ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20210412084002.33582-1-gi-oh.kim@ionos.com
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Before receiving the session name, the error message cannot include any
information about which connection generates the error.
This patch stores the addresses of source and target in the sessname field
to show which generates the error. That field will be over-written
when receiving the session name from client.
Link: https://lore.kernel.org/r/20210325153308.1214057-17-gi-oh.kim@ionos.com
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
