linux.git/drivers/nvme/target/loop.c, branch v4.16

nvmet-loop: use blk_rq_payload_bytes for sgl selection

2018-02-22T08:45:34+00:00

blk_rq_bytes does the wrong thing for special payloads like discards and
might cause the driver to not set up a SGL.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Keith Busch

nvme: host delete_work and reset_work on separate workqueues

2018-01-15T16:09:30+00:00

We need to ensure that delete_work will be hosted on a different
workqueue than all the works we flush or cancel from it.
Otherwise we may hit a circular dependency warning [1].

Also, given that delete_work flushes reset_work, host reset_work
on nvme_reset_wq and delete_work on nvme_delete_wq. In addition,
fix the flushing in the individual drivers to flush nvme_delete_wq
when draining queued deletes.

[1]:
[  178.491942] =============================================
[  178.492718] [ INFO: possible recursive locking detected ]
[  178.493495] 4.9.0-rc4-c844263313a8-lb #3 Tainted: G           OE
[  178.494382] ---------------------------------------------
[  178.495160] kworker/5:1/135 is trying to acquire lock:
[  178.495894]  (
[  178.496120] "nvme-wq"
[  178.496471] ){++++.+}
[  178.496599] , at:
[  178.496921] [] flush_work+0x1a6/0x2d0
[  178.497670]
               but task is already holding lock:
[  178.498499]  (
[  178.498724] "nvme-wq"
[  178.499074] ){++++.+}
[  178.499202] , at:
[  178.499520] [] process_one_work+0x162/0x6a0
[  178.500343]
               other info that might help us debug this:
[  178.501269]  Possible unsafe locking scenario:

[  178.502113]        CPU0
[  178.502472]        ----
[  178.502829]   lock(
[  178.503115] "nvme-wq"
[  178.503467] );
[  178.503716]   lock(
[  178.504001] "nvme-wq"
[  178.504353] );
[  178.504601]
                *** DEADLOCK ***

[  178.505441]  May be due to missing lock nesting notation

[  178.506453] 2 locks held by kworker/5:1/135:
[  178.507068]  #0:
[  178.507330]  (
[  178.507598] "nvme-wq"
[  178.507726] ){++++.+}
[  178.508079] , at:
[  178.508173] [] process_one_work+0x162/0x6a0
[  178.509004]  #1:
[  178.509265]  (
[  178.509532] (&ctrl->delete_work)
[  178.509795] ){+.+.+.}
[  178.510145] , at:
[  178.510239] [] process_one_work+0x162/0x6a0
[  178.511070]
               stack backtrace:
:
[  178.511693] CPU: 5 PID: 135 Comm: kworker/5:1 Tainted: G           OE   4.9.0-rc4-c844263313a8-lb #3
[  178.512974] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014
[  178.514247] Workqueue: nvme-wq nvme_del_ctrl_work [nvme_tcp]
[  178.515071]  ffffc2668175bae0 ffffffffa7450823 ffffffffa88abd80 ffffffffa88abd80
[  178.516195]  ffffc2668175bb98 ffffffffa70eb012 ffffffffa8d8d90d ffff9c472e9ea700
[  178.517318]  ffff9c472e9ea700 ffff9c4700000000 ffff9c4700007200 ab83be61bec0d50e
[  178.518443] Call Trace:
[  178.518807]  [] dump_stack+0x85/0xc2
[  178.519542]  [] __lock_acquire+0x17d2/0x18f0
[  178.520377]  [] ? serial8250_console_putchar+0x27/0x30
[  178.521330]  [] ? wait_for_xmitr+0xa0/0xa0
[  178.522174]  [] ? flush_work+0x18b/0x2d0
[  178.522975]  [] lock_acquire+0x11b/0x220
[  178.523753]  [] ? flush_work+0x1a6/0x2d0
[  178.524535]  [] flush_work+0x1c9/0x2d0
[  178.525291]  [] ? flush_work+0x1a6/0x2d0
[  178.526077]  [] ? flush_workqueue_prep_pwqs+0x220/0x220
[  178.527040]  [] __cancel_work_timer+0x10f/0x1d0
[  178.527907]  [] ? vprintk_default+0x29/0x40
[  178.528726]  [] ? printk+0x48/0x50
[  178.529434]  [] cancel_delayed_work_sync+0x13/0x20
[  178.530381]  [] nvme_stop_ctrl+0x5b/0x70 [nvme_core]
[  178.531314]  [] nvme_del_ctrl_work+0x2c/0x50 [nvme_tcp]
[  178.532271]  [] process_one_work+0x1e1/0x6a0
[  178.533101]  [] ? process_one_work+0x162/0x6a0
[  178.533954]  [] worker_thread+0x4e/0x490
[  178.534735]  [] ? process_one_work+0x6a0/0x6a0
[  178.535588]  [] ? process_one_work+0x6a0/0x6a0
[  178.536441]  [] kthread+0xff/0x120
[  178.537149]  [] ? kthread_park+0x60/0x60
[  178.538094]  [] ? kthread_park+0x60/0x60
[  178.538900]  [] ret_from_fork+0x2a/0x40

Signed-off-by: Roy Shterman 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Christoph Hellwig

nvme-fabrics: protect against module unload during create_ctrl

2018-01-08T10:01:56+00:00

NVMe transport driver module unload may (and usually does) trigger
iteration over the active controllers and delete them all (sometimes
under a mutex).  However, a controller can be created concurrently with
module unload which can lead to leakage of resources (most important char
device node leakage) in case the controller creation occured after the
unload delete and drain sequence.  To protect against this, we take a
module reference to guarantee that the nvme transport driver is not
unloaded while creating a controller.

Signed-off-by: Roy Shterman 
Signed-off-by: Sagi Grimberg 
Reviewed-by: Max Gurtovoy 
Signed-off-by: Christoph Hellwig

nvme-loop: check if queue is ready in queue_rq

2017-11-20T07:28:36+00:00

In case the queue is not LIVE (fully functional and connected at the nvmf
level), we cannot allow any commands other than connect to pass through.

Add a new queue state flag NVME_LOOP_Q_LIVE which is set after nvmf connect
and cleared in queue teardown.

Signed-off-by: Sagi Grimberg 
Signed-off-by: Christoph Hellwig

nvmet: better data length validation

2017-11-11T02:53:25+00:00

Currently the NVMe target stores the expexted data length in req->data_len
and uses that for data transfer decisions, but that does not take the
actual transfer length in the SGLs into account.  So this adds a new
transfer_len field, into which the transport drivers store the actual
transfer length.  We then check the two match before actually executing
the command.

The FC transport driver already had such a field, which is removed in
favour of the common one.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

nvme: remove handling of multiple AEN requests

2017-11-11T02:53:25+00:00

The driver can handle tracking only one AEN request, so this patch
removes handling for multiple ones.

Reviewed-by: Christoph Hellwig 
Reviewed-by: James Smart  
Signed-off-by: Keith Busch 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

nvme: centralize AEN defines

2017-11-11T02:53:25+00:00

All the transports were unnecessarilly duplicating the AEN request
accounting. This patch defines everything in one place.

Signed-off-by: Keith Busch 
Reviewed-by: Guan Junxiong 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

nvme: consolidate common code from ->reset_work

2017-11-01T15:28:06+00:00

No change in behavior except that the FC code cancels two work items a
little later now.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg 
Reviewed-by: James Smart 
Signed-off-by: Christoph Hellwig

nvme: move controller deletion to common code

2017-11-01T15:28:04+00:00

Move the ->delete_work and the associated helpers to common code instead
of duplicating them in every driver.  This also adds the missing reference
get/put for the loop driver.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg 
Reviewed-by: James Smart 
Signed-off-by: Christoph Hellwig

nvme: switch controller refcounting to use struct device

2017-10-27T06:04:07+00:00

Instead of allocating a separate struct device for the character device
handle embedd it into struct nvme_ctrl and use it for the main controller
refcounting.  This removes double refcounting and gets us an automatic
reference for the character device operations.  We keep ctrl->device as a
pointer for now to avoid chaning printks all over, but in the future we
could look into message printing helpers that take a controller structure
similar to what other subsystems do.

Note the delete_ctrl operation always already has a reference (either
through sysfs due this change, or because every open file on the
/dev/nvme-fabrics node has a refernece) when it is entered now, so we
don't need to do the unless_zero variant there.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke