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author | Bart Van Assche <bart.vanassche@sandisk.com> | 2015-05-18 13:22:19 +0200 |
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committer | Doug Ledford <dledford@redhat.com> | 2015-05-18 19:35:55 +0200 |
commit | be34c62ddf39d1931780b07a6f4241393e4ba2ee (patch) | |
tree | ef0ef152ef1ea06170123411883741fb953c5955 /drivers/scsi/scsi_transport_srp.c | |
parent | Linux 4.1-rc4 (diff) | |
download | linux-be34c62ddf39d1931780b07a6f4241393e4ba2ee.tar.xz linux-be34c62ddf39d1931780b07a6f4241393e4ba2ee.zip |
scsi_transport_srp: Introduce srp_wait_for_queuecommand()
Introduce the helper function srp_wait_for_queuecommand().
Move the definition of scsi_request_fn_active(). Add a comment
above srp_wait_for_queuecommand() that support for scsi-mq needs
to be added.
This patch does not change any functionality. A second call to
srp_wait_for_queuecommand() will be introduced in the next patch.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: James Bottomley <JBottomley@Odin.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.13
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/scsi/scsi_transport_srp.c')
-rw-r--r-- | drivers/scsi/scsi_transport_srp.c | 54 |
1 files changed, 31 insertions, 23 deletions
diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c index ae45bd99baed..e05cd7e2d6d3 100644 --- a/drivers/scsi/scsi_transport_srp.c +++ b/drivers/scsi/scsi_transport_srp.c @@ -396,6 +396,36 @@ static void srp_reconnect_work(struct work_struct *work) } } +/** + * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() + * @shost: SCSI host for which to count the number of scsi_request_fn() callers. + * + * To do: add support for scsi-mq in this function. + */ +static int scsi_request_fn_active(struct Scsi_Host *shost) +{ + struct scsi_device *sdev; + struct request_queue *q; + int request_fn_active = 0; + + shost_for_each_device(sdev, shost) { + q = sdev->request_queue; + + spin_lock_irq(q->queue_lock); + request_fn_active += q->request_fn_active; + spin_unlock_irq(q->queue_lock); + } + + return request_fn_active; +} + +/* Wait until ongoing shost->hostt->queuecommand() calls have finished. */ +static void srp_wait_for_queuecommand(struct Scsi_Host *shost) +{ + while (scsi_request_fn_active(shost)) + msleep(20); +} + static void __rport_fail_io_fast(struct srp_rport *rport) { struct Scsi_Host *shost = rport_to_shost(rport); @@ -504,27 +534,6 @@ void srp_start_tl_fail_timers(struct srp_rport *rport) EXPORT_SYMBOL(srp_start_tl_fail_timers); /** - * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() - * @shost: SCSI host for which to count the number of scsi_request_fn() callers. - */ -static int scsi_request_fn_active(struct Scsi_Host *shost) -{ - struct scsi_device *sdev; - struct request_queue *q; - int request_fn_active = 0; - - shost_for_each_device(sdev, shost) { - q = sdev->request_queue; - - spin_lock_irq(q->queue_lock); - request_fn_active += q->request_fn_active; - spin_unlock_irq(q->queue_lock); - } - - return request_fn_active; -} - -/** * srp_reconnect_rport() - reconnect to an SRP target port * @rport: SRP target port. * @@ -559,8 +568,7 @@ int srp_reconnect_rport(struct srp_rport *rport) if (res) goto out; scsi_target_block(&shost->shost_gendev); - while (scsi_request_fn_active(shost)) - msleep(20); + srp_wait_for_queuecommand(shost); res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV; pr_debug("%s (state %d): transport.reconnect() returned %d\n", dev_name(&shost->shost_gendev), rport->state, res); |