linux-stable/drivers/scsi/scsi_transport_srp.c
Linus Torvalds f459c34538 for-4.18/block-20180603
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABCAAGBQJbFIrHAAoJEPfTWPspceCm2+kQAKo7o7HL30aRxJYu+gYafkuW
 PV47zr3e4vhMDEzDaMsh1+V7I7bm3uS+NZu6cFbcV+N9KXFpeb4V4Hvvm5cs+OC3
 WCOBi4eC1h4qnDQ3ZyySrCMN+KHYJ16pZqddEjqw+fhVudx8i+F+jz3Y4ZMDDc3q
 pArKZvjKh2wEuYXUMFTjaXY46IgPt+er94OwvrhyHk+4AcA+Q/oqSfSdDahUC8jb
 BVR3FV4I3NOHUaru0RbrUko13sVZSboWPCIFrlTDz8xXcJOnVHzdVS1WLFDXLHnB
 O8q9cADCfa4K08kz68RxykcJiNxNvz5ChDaG0KloCFO+q1tzYRoXLsfaxyuUDg57
 Zd93OFZC6hAzXdhclDFIuPET9OQIjDzwphodfKKmDsm3wtyOtydpA0o7JUEongp0
 O1gQsEfYOXmQsXlo8Ot+Z7Ne/HvtGZ91JahUa/59edxQbcKaMrktoyQsQ/d1nOEL
 4kXID18wPcFHWRQHYXyVuw6kbpRtQnh/U2m1eenSZ7tVQHwoe6mF3cfSf5MMseak
 k8nAnmsfEvOL4Ar9ftg61GOrImaQlidxOC2A8fmY5r0Sq/ZldvIFIZizsdTTCcni
 8SOTxcQowyqPf5NvMNQ8cKqqCJap3ppj4m7anZNhbypDIF2TmOWsEcXcMDn4y9on
 fax14DPLo59gBRiPCn5f
 =nga/
 -----END PGP SIGNATURE-----

Merge tag 'for-4.18/block-20180603' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - clean up how we pass around gfp_t and
   blk_mq_req_flags_t (Christoph)

 - prepare us to defer scheduler attach (Christoph)

 - clean up drivers handling of bounce buffers (Christoph)

 - fix timeout handling corner cases (Christoph/Bart/Keith)

 - bcache fixes (Coly)

 - prep work for bcachefs and some block layer optimizations (Kent).

 - convert users of bio_sets to using embedded structs (Kent).

 - fixes for the BFQ io scheduler (Paolo/Davide/Filippo)

 - lightnvm fixes and improvements (Matias, with contributions from Hans
   and Javier)

 - adding discard throttling to blk-wbt (me)

 - sbitmap blk-mq-tag handling (me/Omar/Ming).

 - remove the sparc jsflash block driver, acked by DaveM.

 - Kyber scheduler improvement from Jianchao, making it more friendly
   wrt merging.

 - conversion of symbolic proc permissions to octal, from Joe Perches.
   Previously the block parts were a mix of both.

 - nbd fixes (Josef and Kevin Vigor)

 - unify how we handle the various kinds of timestamps that the block
   core and utility code uses (Omar)

 - three NVMe pull requests from Keith and Christoph, bringing AEN to
   feature completeness, file backed namespaces, cq/sq lock split, and
   various fixes

 - various little fixes and improvements all over the map

* tag 'for-4.18/block-20180603' of git://git.kernel.dk/linux-block: (196 commits)
  blk-mq: update nr_requests when switching to 'none' scheduler
  block: don't use blocking queue entered for recursive bio submits
  dm-crypt: fix warning in shutdown path
  lightnvm: pblk: take bitmap alloc. out of critical section
  lightnvm: pblk: kick writer on new flush points
  lightnvm: pblk: only try to recover lines with written smeta
  lightnvm: pblk: remove unnecessary bio_get/put
  lightnvm: pblk: add possibility to set write buffer size manually
  lightnvm: fix partial read error path
  lightnvm: proper error handling for pblk_bio_add_pages
  lightnvm: pblk: fix smeta write error path
  lightnvm: pblk: garbage collect lines with failed writes
  lightnvm: pblk: rework write error recovery path
  lightnvm: pblk: remove dead function
  lightnvm: pass flag on graceful teardown to targets
  lightnvm: pblk: check for chunk size before allocating it
  lightnvm: pblk: remove unnecessary argument
  lightnvm: pblk: remove unnecessary indirection
  lightnvm: pblk: return NVM_ error on failed submission
  lightnvm: pblk: warn in case of corrupted write buffer
  ...
2018-06-04 07:58:06 -07:00

909 lines
25 KiB
C

/*
* SCSI RDMA (SRP) transport class
*
* Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_srp.h>
#include "scsi_priv.h"
struct srp_host_attrs {
atomic_t next_port_id;
};
#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
#define SRP_HOST_ATTRS 0
#define SRP_RPORT_ATTRS 8
struct srp_internal {
struct scsi_transport_template t;
struct srp_function_template *f;
struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
struct transport_container rport_attr_cont;
};
static int scsi_is_srp_rport(const struct device *dev);
#define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
#define dev_to_rport(d) container_of(d, struct srp_rport, dev)
#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r)
{
return dev_to_shost(r->dev.parent);
}
static int find_child_rport(struct device *dev, void *data)
{
struct device **child = data;
if (scsi_is_srp_rport(dev)) {
WARN_ON_ONCE(*child);
*child = dev;
}
return 0;
}
static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost)
{
struct device *child = NULL;
WARN_ON_ONCE(device_for_each_child(&shost->shost_gendev, &child,
find_child_rport) < 0);
return child ? dev_to_rport(child) : NULL;
}
/**
* srp_tmo_valid() - check timeout combination validity
* @reconnect_delay: Reconnect delay in seconds.
* @fast_io_fail_tmo: Fast I/O fail timeout in seconds.
* @dev_loss_tmo: Device loss timeout in seconds.
*
* The combination of the timeout parameters must be such that SCSI commands
* are finished in a reasonable time. Hence do not allow the fast I/O fail
* timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to
* exceed that limit if failing I/O fast has been disabled. Furthermore, these
* parameters must be such that multipath can detect failed paths timely.
* Hence do not allow all three parameters to be disabled simultaneously.
*/
int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, long dev_loss_tmo)
{
if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0)
return -EINVAL;
if (reconnect_delay == 0)
return -EINVAL;
if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
return -EINVAL;
if (fast_io_fail_tmo < 0 &&
dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
return -EINVAL;
if (dev_loss_tmo >= LONG_MAX / HZ)
return -EINVAL;
if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 &&
fast_io_fail_tmo >= dev_loss_tmo)
return -EINVAL;
return 0;
}
EXPORT_SYMBOL_GPL(srp_tmo_valid);
static int srp_host_setup(struct transport_container *tc, struct device *dev,
struct device *cdev)
{
struct Scsi_Host *shost = dev_to_shost(dev);
struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
atomic_set(&srp_host->next_port_id, 0);
return 0;
}
static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
NULL, NULL);
static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
NULL, NULL, NULL);
static ssize_t
show_srp_rport_id(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
return sprintf(buf, "%16phC\n", rport->port_id);
}
static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
static const struct {
u32 value;
char *name;
} srp_rport_role_names[] = {
{SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
{SRP_RPORT_ROLE_TARGET, "SRP Target"},
};
static ssize_t
show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
int i;
char *name = NULL;
for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
if (srp_rport_role_names[i].value == rport->roles) {
name = srp_rport_role_names[i].name;
break;
}
return sprintf(buf, "%s\n", name ? : "unknown");
}
static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
static ssize_t store_srp_rport_delete(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
struct Scsi_Host *shost = dev_to_shost(dev);
struct srp_internal *i = to_srp_internal(shost->transportt);
if (i->f->rport_delete) {
i->f->rport_delete(rport);
return count;
} else {
return -ENOSYS;
}
}
static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete);
static ssize_t show_srp_rport_state(struct device *dev,
struct device_attribute *attr,
char *buf)
{
static const char *const state_name[] = {
[SRP_RPORT_RUNNING] = "running",
[SRP_RPORT_BLOCKED] = "blocked",
[SRP_RPORT_FAIL_FAST] = "fail-fast",
[SRP_RPORT_LOST] = "lost",
};
struct srp_rport *rport = transport_class_to_srp_rport(dev);
enum srp_rport_state state = rport->state;
return sprintf(buf, "%s\n",
(unsigned)state < ARRAY_SIZE(state_name) ?
state_name[state] : "???");
}
static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL);
static ssize_t srp_show_tmo(char *buf, int tmo)
{
return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n");
}
int srp_parse_tmo(int *tmo, const char *buf)
{
int res = 0;
if (strncmp(buf, "off", 3) != 0)
res = kstrtoint(buf, 0, tmo);
else
*tmo = -1;
return res;
}
EXPORT_SYMBOL(srp_parse_tmo);
static ssize_t show_reconnect_delay(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
return srp_show_tmo(buf, rport->reconnect_delay);
}
static ssize_t store_reconnect_delay(struct device *dev,
struct device_attribute *attr,
const char *buf, const size_t count)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
int res, delay;
res = srp_parse_tmo(&delay, buf);
if (res)
goto out;
res = srp_tmo_valid(delay, rport->fast_io_fail_tmo,
rport->dev_loss_tmo);
if (res)
goto out;
if (rport->reconnect_delay <= 0 && delay > 0 &&
rport->state != SRP_RPORT_RUNNING) {
queue_delayed_work(system_long_wq, &rport->reconnect_work,
delay * HZ);
} else if (delay <= 0) {
cancel_delayed_work(&rport->reconnect_work);
}
rport->reconnect_delay = delay;
res = count;
out:
return res;
}
static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay,
store_reconnect_delay);
static ssize_t show_failed_reconnects(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
return sprintf(buf, "%d\n", rport->failed_reconnects);
}
static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL);
static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
return srp_show_tmo(buf, rport->fast_io_fail_tmo);
}
static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
int res;
int fast_io_fail_tmo;
res = srp_parse_tmo(&fast_io_fail_tmo, buf);
if (res)
goto out;
res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo,
rport->dev_loss_tmo);
if (res)
goto out;
rport->fast_io_fail_tmo = fast_io_fail_tmo;
res = count;
out:
return res;
}
static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
show_srp_rport_fast_io_fail_tmo,
store_srp_rport_fast_io_fail_tmo);
static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
return srp_show_tmo(buf, rport->dev_loss_tmo);
}
static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
int res;
int dev_loss_tmo;
res = srp_parse_tmo(&dev_loss_tmo, buf);
if (res)
goto out;
res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo,
dev_loss_tmo);
if (res)
goto out;
rport->dev_loss_tmo = dev_loss_tmo;
res = count;
out:
return res;
}
static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR,
show_srp_rport_dev_loss_tmo,
store_srp_rport_dev_loss_tmo);
static int srp_rport_set_state(struct srp_rport *rport,
enum srp_rport_state new_state)
{
enum srp_rport_state old_state = rport->state;
lockdep_assert_held(&rport->mutex);
switch (new_state) {
case SRP_RPORT_RUNNING:
switch (old_state) {
case SRP_RPORT_LOST:
goto invalid;
default:
break;
}
break;
case SRP_RPORT_BLOCKED:
switch (old_state) {
case SRP_RPORT_RUNNING:
break;
default:
goto invalid;
}
break;
case SRP_RPORT_FAIL_FAST:
switch (old_state) {
case SRP_RPORT_LOST:
goto invalid;
default:
break;
}
break;
case SRP_RPORT_LOST:
break;
}
rport->state = new_state;
return 0;
invalid:
return -EINVAL;
}
/**
* srp_reconnect_work() - reconnect and schedule a new attempt if necessary
* @work: Work structure used for scheduling this operation.
*/
static void srp_reconnect_work(struct work_struct *work)
{
struct srp_rport *rport = container_of(to_delayed_work(work),
struct srp_rport, reconnect_work);
struct Scsi_Host *shost = rport_to_shost(rport);
int delay, res;
res = srp_reconnect_rport(rport);
if (res != 0) {
shost_printk(KERN_ERR, shost,
"reconnect attempt %d failed (%d)\n",
++rport->failed_reconnects, res);
delay = rport->reconnect_delay *
min(100, max(1, rport->failed_reconnects - 10));
if (delay > 0)
queue_delayed_work(system_long_wq,
&rport->reconnect_work, delay * HZ);
}
}
static void __rport_fail_io_fast(struct srp_rport *rport)
{
struct Scsi_Host *shost = rport_to_shost(rport);
struct srp_internal *i;
lockdep_assert_held(&rport->mutex);
if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST))
return;
/*
* Call scsi_target_block() to wait for ongoing shost->queuecommand()
* calls before invoking i->f->terminate_rport_io().
*/
scsi_target_block(rport->dev.parent);
scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
/* Involve the LLD if possible to terminate all I/O on the rport. */
i = to_srp_internal(shost->transportt);
if (i->f->terminate_rport_io)
i->f->terminate_rport_io(rport);
}
/**
* rport_fast_io_fail_timedout() - fast I/O failure timeout handler
* @work: Work structure used for scheduling this operation.
*/
static void rport_fast_io_fail_timedout(struct work_struct *work)
{
struct srp_rport *rport = container_of(to_delayed_work(work),
struct srp_rport, fast_io_fail_work);
struct Scsi_Host *shost = rport_to_shost(rport);
pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n",
dev_name(&rport->dev), dev_name(&shost->shost_gendev));
mutex_lock(&rport->mutex);
if (rport->state == SRP_RPORT_BLOCKED)
__rport_fail_io_fast(rport);
mutex_unlock(&rport->mutex);
}
/**
* rport_dev_loss_timedout() - device loss timeout handler
* @work: Work structure used for scheduling this operation.
*/
static void rport_dev_loss_timedout(struct work_struct *work)
{
struct srp_rport *rport = container_of(to_delayed_work(work),
struct srp_rport, dev_loss_work);
struct Scsi_Host *shost = rport_to_shost(rport);
struct srp_internal *i = to_srp_internal(shost->transportt);
pr_info("dev_loss_tmo expired for SRP %s / %s.\n",
dev_name(&rport->dev), dev_name(&shost->shost_gendev));
mutex_lock(&rport->mutex);
WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0);
scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
mutex_unlock(&rport->mutex);
i->f->rport_delete(rport);
}
static void __srp_start_tl_fail_timers(struct srp_rport *rport)
{
struct Scsi_Host *shost = rport_to_shost(rport);
int delay, fast_io_fail_tmo, dev_loss_tmo;
lockdep_assert_held(&rport->mutex);
delay = rport->reconnect_delay;
fast_io_fail_tmo = rport->fast_io_fail_tmo;
dev_loss_tmo = rport->dev_loss_tmo;
pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev),
rport->state);
if (rport->state == SRP_RPORT_LOST)
return;
if (delay > 0)
queue_delayed_work(system_long_wq, &rport->reconnect_work,
1UL * delay * HZ);
if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) &&
srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
rport->state);
scsi_target_block(&shost->shost_gendev);
if (fast_io_fail_tmo >= 0)
queue_delayed_work(system_long_wq,
&rport->fast_io_fail_work,
1UL * fast_io_fail_tmo * HZ);
if (dev_loss_tmo >= 0)
queue_delayed_work(system_long_wq,
&rport->dev_loss_work,
1UL * dev_loss_tmo * HZ);
}
}
/**
* srp_start_tl_fail_timers() - start the transport layer failure timers
* @rport: SRP target port.
*
* Start the transport layer fast I/O failure and device loss timers. Do not
* modify a timer that was already started.
*/
void srp_start_tl_fail_timers(struct srp_rport *rport)
{
mutex_lock(&rport->mutex);
__srp_start_tl_fail_timers(rport);
mutex_unlock(&rport->mutex);
}
EXPORT_SYMBOL(srp_start_tl_fail_timers);
/**
* srp_reconnect_rport() - reconnect to an SRP target port
* @rport: SRP target port.
*
* Blocks SCSI command queueing before invoking reconnect() such that
* queuecommand() won't be invoked concurrently with reconnect() from outside
* the SCSI EH. This is important since a reconnect() implementation may
* reallocate resources needed by queuecommand().
*
* Notes:
* - This function neither waits until outstanding requests have finished nor
* tries to abort these. It is the responsibility of the reconnect()
* function to finish outstanding commands before reconnecting to the target
* port.
* - It is the responsibility of the caller to ensure that the resources
* reallocated by the reconnect() function won't be used while this function
* is in progress. One possible strategy is to invoke this function from
* the context of the SCSI EH thread only. Another possible strategy is to
* lock the rport mutex inside each SCSI LLD callback that can be invoked by
* the SCSI EH (the scsi_host_template.eh_*() functions and also the
* scsi_host_template.queuecommand() function).
*/
int srp_reconnect_rport(struct srp_rport *rport)
{
struct Scsi_Host *shost = rport_to_shost(rport);
struct srp_internal *i = to_srp_internal(shost->transportt);
struct scsi_device *sdev;
int res;
pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev));
res = mutex_lock_interruptible(&rport->mutex);
if (res)
goto out;
scsi_target_block(&shost->shost_gendev);
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);
if (res == 0) {
cancel_delayed_work(&rport->fast_io_fail_work);
cancel_delayed_work(&rport->dev_loss_work);
rport->failed_reconnects = 0;
srp_rport_set_state(rport, SRP_RPORT_RUNNING);
scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING);
/*
* If the SCSI error handler has offlined one or more devices,
* invoking scsi_target_unblock() won't change the state of
* these devices into running so do that explicitly.
*/
shost_for_each_device(sdev, shost) {
mutex_lock(&sdev->state_mutex);
if (sdev->sdev_state == SDEV_OFFLINE)
sdev->sdev_state = SDEV_RUNNING;
mutex_unlock(&sdev->state_mutex);
}
} else if (rport->state == SRP_RPORT_RUNNING) {
/*
* srp_reconnect_rport() has been invoked with fast_io_fail
* and dev_loss off. Mark the port as failed and start the TL
* failure timers if these had not yet been started.
*/
__rport_fail_io_fast(rport);
scsi_target_unblock(&shost->shost_gendev,
SDEV_TRANSPORT_OFFLINE);
__srp_start_tl_fail_timers(rport);
} else if (rport->state != SRP_RPORT_BLOCKED) {
scsi_target_unblock(&shost->shost_gendev,
SDEV_TRANSPORT_OFFLINE);
}
mutex_unlock(&rport->mutex);
out:
return res;
}
EXPORT_SYMBOL(srp_reconnect_rport);
/**
* srp_timed_out() - SRP transport intercept of the SCSI timeout EH
* @scmd: SCSI command.
*
* If a timeout occurs while an rport is in the blocked state, ask the SCSI
* EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core
* handle the timeout (BLK_EH_DONE).
*
* Note: This function is called from soft-IRQ context and with the request
* queue lock held.
*/
enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd)
{
struct scsi_device *sdev = scmd->device;
struct Scsi_Host *shost = sdev->host;
struct srp_internal *i = to_srp_internal(shost->transportt);
struct srp_rport *rport = shost_to_rport(shost);
pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev));
return rport && rport->fast_io_fail_tmo < 0 &&
rport->dev_loss_tmo < 0 &&
i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ?
BLK_EH_RESET_TIMER : BLK_EH_DONE;
}
EXPORT_SYMBOL(srp_timed_out);
static void srp_rport_release(struct device *dev)
{
struct srp_rport *rport = dev_to_rport(dev);
put_device(dev->parent);
kfree(rport);
}
static int scsi_is_srp_rport(const struct device *dev)
{
return dev->release == srp_rport_release;
}
static int srp_rport_match(struct attribute_container *cont,
struct device *dev)
{
struct Scsi_Host *shost;
struct srp_internal *i;
if (!scsi_is_srp_rport(dev))
return 0;
shost = dev_to_shost(dev->parent);
if (!shost->transportt)
return 0;
if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
return 0;
i = to_srp_internal(shost->transportt);
return &i->rport_attr_cont.ac == cont;
}
static int srp_host_match(struct attribute_container *cont, struct device *dev)
{
struct Scsi_Host *shost;
struct srp_internal *i;
if (!scsi_is_host_device(dev))
return 0;
shost = dev_to_shost(dev);
if (!shost->transportt)
return 0;
if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
return 0;
i = to_srp_internal(shost->transportt);
return &i->t.host_attrs.ac == cont;
}
/**
* srp_rport_get() - increment rport reference count
* @rport: SRP target port.
*/
void srp_rport_get(struct srp_rport *rport)
{
get_device(&rport->dev);
}
EXPORT_SYMBOL(srp_rport_get);
/**
* srp_rport_put() - decrement rport reference count
* @rport: SRP target port.
*/
void srp_rport_put(struct srp_rport *rport)
{
put_device(&rport->dev);
}
EXPORT_SYMBOL(srp_rport_put);
/**
* srp_rport_add - add a SRP remote port to the device hierarchy
* @shost: scsi host the remote port is connected to.
* @ids: The port id for the remote port.
*
* Publishes a port to the rest of the system.
*/
struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
struct srp_rport_identifiers *ids)
{
struct srp_rport *rport;
struct device *parent = &shost->shost_gendev;
struct srp_internal *i = to_srp_internal(shost->transportt);
int id, ret;
rport = kzalloc(sizeof(*rport), GFP_KERNEL);
if (!rport)
return ERR_PTR(-ENOMEM);
mutex_init(&rport->mutex);
device_initialize(&rport->dev);
rport->dev.parent = get_device(parent);
rport->dev.release = srp_rport_release;
memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
rport->roles = ids->roles;
if (i->f->reconnect)
rport->reconnect_delay = i->f->reconnect_delay ?
*i->f->reconnect_delay : 10;
INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work);
rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ?
*i->f->fast_io_fail_tmo : 15;
rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60;
INIT_DELAYED_WORK(&rport->fast_io_fail_work,
rport_fast_io_fail_timedout);
INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout);
id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id);
transport_setup_device(&rport->dev);
ret = device_add(&rport->dev);
if (ret) {
transport_destroy_device(&rport->dev);
put_device(&rport->dev);
return ERR_PTR(ret);
}
transport_add_device(&rport->dev);
transport_configure_device(&rport->dev);
return rport;
}
EXPORT_SYMBOL_GPL(srp_rport_add);
/**
* srp_rport_del - remove a SRP remote port
* @rport: SRP remote port to remove
*
* Removes the specified SRP remote port.
*/
void srp_rport_del(struct srp_rport *rport)
{
struct device *dev = &rport->dev;
transport_remove_device(dev);
device_del(dev);
transport_destroy_device(dev);
put_device(dev);
}
EXPORT_SYMBOL_GPL(srp_rport_del);
static int do_srp_rport_del(struct device *dev, void *data)
{
if (scsi_is_srp_rport(dev))
srp_rport_del(dev_to_rport(dev));
return 0;
}
/**
* srp_remove_host - tear down a Scsi_Host's SRP data structures
* @shost: Scsi Host that is torn down
*
* Removes all SRP remote ports for a given Scsi_Host.
* Must be called just before scsi_remove_host for SRP HBAs.
*/
void srp_remove_host(struct Scsi_Host *shost)
{
device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
}
EXPORT_SYMBOL_GPL(srp_remove_host);
/**
* srp_stop_rport_timers - stop the transport layer recovery timers
* @rport: SRP remote port for which to stop the timers.
*
* Must be called after srp_remove_host() and scsi_remove_host(). The caller
* must hold a reference on the rport (rport->dev) and on the SCSI host
* (rport->dev.parent).
*/
void srp_stop_rport_timers(struct srp_rport *rport)
{
mutex_lock(&rport->mutex);
if (rport->state == SRP_RPORT_BLOCKED)
__rport_fail_io_fast(rport);
srp_rport_set_state(rport, SRP_RPORT_LOST);
mutex_unlock(&rport->mutex);
cancel_delayed_work_sync(&rport->reconnect_work);
cancel_delayed_work_sync(&rport->fast_io_fail_work);
cancel_delayed_work_sync(&rport->dev_loss_work);
}
EXPORT_SYMBOL_GPL(srp_stop_rport_timers);
/**
* srp_attach_transport - instantiate SRP transport template
* @ft: SRP transport class function template
*/
struct scsi_transport_template *
srp_attach_transport(struct srp_function_template *ft)
{
int count;
struct srp_internal *i;
i = kzalloc(sizeof(*i), GFP_KERNEL);
if (!i)
return NULL;
i->t.host_size = sizeof(struct srp_host_attrs);
i->t.host_attrs.ac.attrs = &i->host_attrs[0];
i->t.host_attrs.ac.class = &srp_host_class.class;
i->t.host_attrs.ac.match = srp_host_match;
i->host_attrs[0] = NULL;
transport_container_register(&i->t.host_attrs);
i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
i->rport_attr_cont.ac.class = &srp_rport_class.class;
i->rport_attr_cont.ac.match = srp_rport_match;
count = 0;
i->rport_attrs[count++] = &dev_attr_port_id;
i->rport_attrs[count++] = &dev_attr_roles;
if (ft->has_rport_state) {
i->rport_attrs[count++] = &dev_attr_state;
i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo;
i->rport_attrs[count++] = &dev_attr_dev_loss_tmo;
}
if (ft->reconnect) {
i->rport_attrs[count++] = &dev_attr_reconnect_delay;
i->rport_attrs[count++] = &dev_attr_failed_reconnects;
}
if (ft->rport_delete)
i->rport_attrs[count++] = &dev_attr_delete;
i->rport_attrs[count++] = NULL;
BUG_ON(count > ARRAY_SIZE(i->rport_attrs));
transport_container_register(&i->rport_attr_cont);
i->f = ft;
return &i->t;
}
EXPORT_SYMBOL_GPL(srp_attach_transport);
/**
* srp_release_transport - release SRP transport template instance
* @t: transport template instance
*/
void srp_release_transport(struct scsi_transport_template *t)
{
struct srp_internal *i = to_srp_internal(t);
transport_container_unregister(&i->t.host_attrs);
transport_container_unregister(&i->rport_attr_cont);
kfree(i);
}
EXPORT_SYMBOL_GPL(srp_release_transport);
static __init int srp_transport_init(void)
{
int ret;
ret = transport_class_register(&srp_host_class);
if (ret)
return ret;
ret = transport_class_register(&srp_rport_class);
if (ret)
goto unregister_host_class;
return 0;
unregister_host_class:
transport_class_unregister(&srp_host_class);
return ret;
}
static void __exit srp_transport_exit(void)
{
transport_class_unregister(&srp_host_class);
transport_class_unregister(&srp_rport_class);
}
MODULE_AUTHOR("FUJITA Tomonori");
MODULE_DESCRIPTION("SRP Transport Attributes");
MODULE_LICENSE("GPL");
module_init(srp_transport_init);
module_exit(srp_transport_exit);