linux/drivers/scsi/scsi.c
Linus Torvalds ba6d10ab80 SCSI misc on 20190709
This is mostly update of the usual drivers: qla2xxx, hpsa, lpfc, ufs,
 mpt3sas, ibmvscsi, megaraid_sas, bnx2fc and hisi_sas as well as the
 removal of the osst driver (I heard from Willem privately that he
 would like the driver removed because all his test hardware has
 failed).  Plus number of minor changes, spelling fixes and other
 trivia.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This is mostly update of the usual drivers: qla2xxx, hpsa, lpfc, ufs,
  mpt3sas, ibmvscsi, megaraid_sas, bnx2fc and hisi_sas as well as the
  removal of the osst driver (I heard from Willem privately that he
  would like the driver removed because all his test hardware has
  failed). Plus number of minor changes, spelling fixes and other
  trivia.

  The big merge conflict this time around is the SPDX licence tags.
  Following discussion on linux-next, we believe our version to be more
  accurate than the one in the tree, so the resolution is to take our
  version for all the SPDX conflicts"

Note on the SPDX license tag conversion conflicts: the SCSI tree had
done its own SPDX conversion, which in some cases conflicted with the
treewide ones done by Thomas & co.

In almost all cases, the conflicts were purely syntactic: the SCSI tree
used the old-style SPDX tags ("GPL-2.0" and "GPL-2.0+") while the
treewide conversion had used the new-style ones ("GPL-2.0-only" and
"GPL-2.0-or-later").

In these cases I picked the new-style one.

In a few cases, the SPDX conversion was actually different, though.  As
explained by James above, and in more detail in a pre-pull-request
thread:

 "The other problem is actually substantive: In the libsas code Luben
  Tuikov originally specified gpl 2.0 only by dint of stating:

  * This file is licensed under GPLv2.

  In all the libsas files, but then muddied the water by quoting GPLv2
  verbatim (which includes the or later than language). So for these
  files Christoph did the conversion to v2 only SPDX tags and Thomas
  converted to v2 or later tags"

So in those cases, where the spdx tag substantially mattered, I took the
SCSI tree conversion of it, but then also took the opportunity to turn
the old-style "GPL-2.0" into a new-style "GPL-2.0-only" tag.

Similarly, when there were whitespace differences or other differences
to the comments around the copyright notices, I took the version from
the SCSI tree as being the more specific conversion.

Finally, in the spdx conversions that had no conflicts (because the
treewide ones hadn't been done for those files), I just took the SCSI
tree version as-is, even if it was old-style.  The old-style conversions
are perfectly valid, even if the "-only" and "-or-later" versions are
perhaps more descriptive.

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (185 commits)
  scsi: qla2xxx: move IO flush to the front of NVME rport unregistration
  scsi: qla2xxx: Fix NVME cmd and LS cmd timeout race condition
  scsi: qla2xxx: on session delete, return nvme cmd
  scsi: qla2xxx: Fix kernel crash after disconnecting NVMe devices
  scsi: megaraid_sas: Update driver version to 07.710.06.00-rc1
  scsi: megaraid_sas: Introduce various Aero performance modes
  scsi: megaraid_sas: Use high IOPS queues based on IO workload
  scsi: megaraid_sas: Set affinity for high IOPS reply queues
  scsi: megaraid_sas: Enable coalescing for high IOPS queues
  scsi: megaraid_sas: Add support for High IOPS queues
  scsi: megaraid_sas: Add support for MPI toolbox commands
  scsi: megaraid_sas: Offload Aero RAID5/6 division calculations to driver
  scsi: megaraid_sas: RAID1 PCI bandwidth limit algorithm is applicable for only Ventura
  scsi: megaraid_sas: megaraid_sas: Add check for count returned by HOST_DEVICE_LIST DCMD
  scsi: megaraid_sas: Handle sequence JBOD map failure at driver level
  scsi: megaraid_sas: Don't send FPIO to RL Bypass queue
  scsi: megaraid_sas: In probe context, retry IOC INIT once if firmware is in fault
  scsi: megaraid_sas: Release Mutex lock before OCR in case of DCMD timeout
  scsi: megaraid_sas: Call disable_irq from process IRQ poll
  scsi: megaraid_sas: Remove few debug counters from IO path
  ...
2019-07-11 15:14:01 -07:00

823 lines
22 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* scsi.c Copyright (C) 1992 Drew Eckhardt
* Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
* Copyright (C) 2002, 2003 Christoph Hellwig
*
* generic mid-level SCSI driver
* Initial versions: Drew Eckhardt
* Subsequent revisions: Eric Youngdale
*
* <drew@colorado.edu>
*
* Bug correction thanks go to :
* Rik Faith <faith@cs.unc.edu>
* Tommy Thorn <tthorn>
* Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
*
* Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
* add scatter-gather, multiple outstanding request, and other
* enhancements.
*
* Native multichannel, wide scsi, /proc/scsi and hot plugging
* support added by Michael Neuffer <mike@i-connect.net>
*
* Added request_module("scsi_hostadapter") for kerneld:
* (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
* Bjorn Ekwall <bj0rn@blox.se>
* (changed to kmod)
*
* Major improvements to the timeout, abort, and reset processing,
* as well as performance modifications for large queue depths by
* Leonard N. Zubkoff <lnz@dandelion.com>
*
* Converted cli() code to spinlocks, Ingo Molnar
*
* Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
*
* out_of_space hacks, D. Gilbert (dpg) 990608
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/unistd.h>
#include <linux/spinlock.h>
#include <linux/kmod.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/async.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include "scsi_priv.h"
#include "scsi_logging.h"
#define CREATE_TRACE_POINTS
#include <trace/events/scsi.h>
/*
* Definitions and constants.
*/
/*
* Note - the initial logging level can be set here to log events at boot time.
* After the system is up, you may enable logging via the /proc interface.
*/
unsigned int scsi_logging_level;
#if defined(CONFIG_SCSI_LOGGING)
EXPORT_SYMBOL(scsi_logging_level);
#endif
/*
* Domain for asynchronous system resume operations. It is marked 'exclusive'
* to avoid being included in the async_synchronize_full() that is invoked by
* dpm_resume().
*/
ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
EXPORT_SYMBOL(scsi_sd_pm_domain);
/**
* scsi_put_command - Free a scsi command block
* @cmd: command block to free
*
* Returns: Nothing.
*
* Notes: The command must not belong to any lists.
*/
void scsi_put_command(struct scsi_cmnd *cmd)
{
scsi_del_cmd_from_list(cmd);
BUG_ON(delayed_work_pending(&cmd->abort_work));
}
#ifdef CONFIG_SCSI_LOGGING
void scsi_log_send(struct scsi_cmnd *cmd)
{
unsigned int level;
/*
* If ML QUEUE log level is greater than or equal to:
*
* 1: nothing (match completion)
*
* 2: log opcode + command of all commands + cmd address
*
* 3: same as 2
*
* 4: same as 3
*/
if (unlikely(scsi_logging_level)) {
level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
SCSI_LOG_MLQUEUE_BITS);
if (level > 1) {
scmd_printk(KERN_INFO, cmd,
"Send: scmd 0x%p\n", cmd);
scsi_print_command(cmd);
}
}
}
void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
{
unsigned int level;
/*
* If ML COMPLETE log level is greater than or equal to:
*
* 1: log disposition, result, opcode + command, and conditionally
* sense data for failures or non SUCCESS dispositions.
*
* 2: same as 1 but for all command completions.
*
* 3: same as 2
*
* 4: same as 3 plus dump extra junk
*/
if (unlikely(scsi_logging_level)) {
level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
SCSI_LOG_MLCOMPLETE_BITS);
if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
(level > 1)) {
scsi_print_result(cmd, "Done", disposition);
scsi_print_command(cmd);
if (status_byte(cmd->result) == CHECK_CONDITION)
scsi_print_sense(cmd);
if (level > 3)
scmd_printk(KERN_INFO, cmd,
"scsi host busy %d failed %d\n",
scsi_host_busy(cmd->device->host),
cmd->device->host->host_failed);
}
}
}
#endif
/**
* scsi_finish_command - cleanup and pass command back to upper layer
* @cmd: the command
*
* Description: Pass command off to upper layer for finishing of I/O
* request, waking processes that are waiting on results,
* etc.
*/
void scsi_finish_command(struct scsi_cmnd *cmd)
{
struct scsi_device *sdev = cmd->device;
struct scsi_target *starget = scsi_target(sdev);
struct Scsi_Host *shost = sdev->host;
struct scsi_driver *drv;
unsigned int good_bytes;
scsi_device_unbusy(sdev);
/*
* Clear the flags that say that the device/target/host is no longer
* capable of accepting new commands.
*/
if (atomic_read(&shost->host_blocked))
atomic_set(&shost->host_blocked, 0);
if (atomic_read(&starget->target_blocked))
atomic_set(&starget->target_blocked, 0);
if (atomic_read(&sdev->device_blocked))
atomic_set(&sdev->device_blocked, 0);
/*
* If we have valid sense information, then some kind of recovery
* must have taken place. Make a note of this.
*/
if (SCSI_SENSE_VALID(cmd))
cmd->result |= (DRIVER_SENSE << 24);
SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
"Notifying upper driver of completion "
"(result %x)\n", cmd->result));
good_bytes = scsi_bufflen(cmd);
if (!blk_rq_is_passthrough(cmd->request)) {
int old_good_bytes = good_bytes;
drv = scsi_cmd_to_driver(cmd);
if (drv->done)
good_bytes = drv->done(cmd);
/*
* USB may not give sense identifying bad sector and
* simply return a residue instead, so subtract off the
* residue if drv->done() error processing indicates no
* change to the completion length.
*/
if (good_bytes == old_good_bytes)
good_bytes -= scsi_get_resid(cmd);
}
scsi_io_completion(cmd, good_bytes);
}
/**
* scsi_change_queue_depth - change a device's queue depth
* @sdev: SCSI Device in question
* @depth: number of commands allowed to be queued to the driver
*
* Sets the device queue depth and returns the new value.
*/
int scsi_change_queue_depth(struct scsi_device *sdev, int depth)
{
if (depth > 0) {
sdev->queue_depth = depth;
wmb();
}
if (sdev->request_queue)
blk_set_queue_depth(sdev->request_queue, depth);
return sdev->queue_depth;
}
EXPORT_SYMBOL(scsi_change_queue_depth);
/**
* scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
* @sdev: SCSI Device in question
* @depth: Current number of outstanding SCSI commands on this device,
* not counting the one returned as QUEUE_FULL.
*
* Description: This function will track successive QUEUE_FULL events on a
* specific SCSI device to determine if and when there is a
* need to adjust the queue depth on the device.
*
* Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
* -1 - Drop back to untagged operation using host->cmd_per_lun
* as the untagged command depth
*
* Lock Status: None held on entry
*
* Notes: Low level drivers may call this at any time and we will do
* "The Right Thing." We are interrupt context safe.
*/
int scsi_track_queue_full(struct scsi_device *sdev, int depth)
{
/*
* Don't let QUEUE_FULLs on the same
* jiffies count, they could all be from
* same event.
*/
if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
return 0;
sdev->last_queue_full_time = jiffies;
if (sdev->last_queue_full_depth != depth) {
sdev->last_queue_full_count = 1;
sdev->last_queue_full_depth = depth;
} else {
sdev->last_queue_full_count++;
}
if (sdev->last_queue_full_count <= 10)
return 0;
return scsi_change_queue_depth(sdev, depth);
}
EXPORT_SYMBOL(scsi_track_queue_full);
/**
* scsi_vpd_inquiry - Request a device provide us with a VPD page
* @sdev: The device to ask
* @buffer: Where to put the result
* @page: Which Vital Product Data to return
* @len: The length of the buffer
*
* This is an internal helper function. You probably want to use
* scsi_get_vpd_page instead.
*
* Returns size of the vpd page on success or a negative error number.
*/
static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
u8 page, unsigned len)
{
int result;
unsigned char cmd[16];
if (len < 4)
return -EINVAL;
cmd[0] = INQUIRY;
cmd[1] = 1; /* EVPD */
cmd[2] = page;
cmd[3] = len >> 8;
cmd[4] = len & 0xff;
cmd[5] = 0; /* Control byte */
/*
* I'm not convinced we need to try quite this hard to get VPD, but
* all the existing users tried this hard.
*/
result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
len, NULL, 30 * HZ, 3, NULL);
if (result)
return -EIO;
/* Sanity check that we got the page back that we asked for */
if (buffer[1] != page)
return -EIO;
return get_unaligned_be16(&buffer[2]) + 4;
}
/**
* scsi_get_vpd_page - Get Vital Product Data from a SCSI device
* @sdev: The device to ask
* @page: Which Vital Product Data to return
* @buf: where to store the VPD
* @buf_len: number of bytes in the VPD buffer area
*
* SCSI devices may optionally supply Vital Product Data. Each 'page'
* of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
* If the device supports this VPD page, this routine returns a pointer
* to a buffer containing the data from that page. The caller is
* responsible for calling kfree() on this pointer when it is no longer
* needed. If we cannot retrieve the VPD page this routine returns %NULL.
*/
int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
int buf_len)
{
int i, result;
if (sdev->skip_vpd_pages)
goto fail;
/* Ask for all the pages supported by this device */
result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
if (result < 4)
goto fail;
/* If the user actually wanted this page, we can skip the rest */
if (page == 0)
return 0;
for (i = 4; i < min(result, buf_len); i++)
if (buf[i] == page)
goto found;
if (i < result && i >= buf_len)
/* ran off the end of the buffer, give us benefit of doubt */
goto found;
/* The device claims it doesn't support the requested page */
goto fail;
found:
result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
if (result < 0)
goto fail;
return 0;
fail:
return -EINVAL;
}
EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
/**
* scsi_get_vpd_buf - Get Vital Product Data from a SCSI device
* @sdev: The device to ask
* @page: Which Vital Product Data to return
*
* Returns %NULL upon failure.
*/
static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page)
{
struct scsi_vpd *vpd_buf;
int vpd_len = SCSI_VPD_PG_LEN, result;
retry_pg:
vpd_buf = kmalloc(sizeof(*vpd_buf) + vpd_len, GFP_KERNEL);
if (!vpd_buf)
return NULL;
result = scsi_vpd_inquiry(sdev, vpd_buf->data, page, vpd_len);
if (result < 0) {
kfree(vpd_buf);
return NULL;
}
if (result > vpd_len) {
vpd_len = result;
kfree(vpd_buf);
goto retry_pg;
}
vpd_buf->len = result;
return vpd_buf;
}
static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page,
struct scsi_vpd __rcu **sdev_vpd_buf)
{
struct scsi_vpd *vpd_buf;
vpd_buf = scsi_get_vpd_buf(sdev, page);
if (!vpd_buf)
return;
mutex_lock(&sdev->inquiry_mutex);
rcu_swap_protected(*sdev_vpd_buf, vpd_buf,
lockdep_is_held(&sdev->inquiry_mutex));
mutex_unlock(&sdev->inquiry_mutex);
if (vpd_buf)
kfree_rcu(vpd_buf, rcu);
}
/**
* scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
* @sdev: The device to ask
*
* Attach the 'Device Identification' VPD page (0x83) and the
* 'Unit Serial Number' VPD page (0x80) to a SCSI device
* structure. This information can be used to identify the device
* uniquely.
*/
void scsi_attach_vpd(struct scsi_device *sdev)
{
int i;
struct scsi_vpd *vpd_buf;
if (!scsi_device_supports_vpd(sdev))
return;
/* Ask for all the pages supported by this device */
vpd_buf = scsi_get_vpd_buf(sdev, 0);
if (!vpd_buf)
return;
for (i = 4; i < vpd_buf->len; i++) {
if (vpd_buf->data[i] == 0x80)
scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80);
if (vpd_buf->data[i] == 0x83)
scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83);
}
kfree(vpd_buf);
}
/**
* scsi_report_opcode - Find out if a given command opcode is supported
* @sdev: scsi device to query
* @buffer: scratch buffer (must be at least 20 bytes long)
* @len: length of buffer
* @opcode: opcode for command to look up
*
* Uses the REPORT SUPPORTED OPERATION CODES to look up the given
* opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
* unsupported and 1 if the device claims to support the command.
*/
int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
unsigned int len, unsigned char opcode)
{
unsigned char cmd[16];
struct scsi_sense_hdr sshdr;
int result;
if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
return -EINVAL;
memset(cmd, 0, 16);
cmd[0] = MAINTENANCE_IN;
cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
cmd[2] = 1; /* One command format */
cmd[3] = opcode;
put_unaligned_be32(len, &cmd[6]);
memset(buffer, 0, len);
result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
&sshdr, 30 * HZ, 3, NULL);
if (result && scsi_sense_valid(&sshdr) &&
sshdr.sense_key == ILLEGAL_REQUEST &&
(sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
return -EINVAL;
if ((buffer[1] & 3) == 3) /* Command supported */
return 1;
return 0;
}
EXPORT_SYMBOL(scsi_report_opcode);
/**
* scsi_device_get - get an additional reference to a scsi_device
* @sdev: device to get a reference to
*
* Description: Gets a reference to the scsi_device and increments the use count
* of the underlying LLDD module. You must hold host_lock of the
* parent Scsi_Host or already have a reference when calling this.
*
* This will fail if a device is deleted or cancelled, or when the LLD module
* is in the process of being unloaded.
*/
int scsi_device_get(struct scsi_device *sdev)
{
if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
goto fail;
if (!get_device(&sdev->sdev_gendev))
goto fail;
if (!try_module_get(sdev->host->hostt->module))
goto fail_put_device;
return 0;
fail_put_device:
put_device(&sdev->sdev_gendev);
fail:
return -ENXIO;
}
EXPORT_SYMBOL(scsi_device_get);
/**
* scsi_device_put - release a reference to a scsi_device
* @sdev: device to release a reference on.
*
* Description: Release a reference to the scsi_device and decrements the use
* count of the underlying LLDD module. The device is freed once the last
* user vanishes.
*/
void scsi_device_put(struct scsi_device *sdev)
{
module_put(sdev->host->hostt->module);
put_device(&sdev->sdev_gendev);
}
EXPORT_SYMBOL(scsi_device_put);
/* helper for shost_for_each_device, see that for documentation */
struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
struct scsi_device *prev)
{
struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
struct scsi_device *next = NULL;
unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
while (list->next != &shost->__devices) {
next = list_entry(list->next, struct scsi_device, siblings);
/* skip devices that we can't get a reference to */
if (!scsi_device_get(next))
break;
next = NULL;
list = list->next;
}
spin_unlock_irqrestore(shost->host_lock, flags);
if (prev)
scsi_device_put(prev);
return next;
}
EXPORT_SYMBOL(__scsi_iterate_devices);
/**
* starget_for_each_device - helper to walk all devices of a target
* @starget: target whose devices we want to iterate over.
* @data: Opaque passed to each function call.
* @fn: Function to call on each device
*
* This traverses over each device of @starget. The devices have
* a reference that must be released by scsi_host_put when breaking
* out of the loop.
*/
void starget_for_each_device(struct scsi_target *starget, void *data,
void (*fn)(struct scsi_device *, void *))
{
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
struct scsi_device *sdev;
shost_for_each_device(sdev, shost) {
if ((sdev->channel == starget->channel) &&
(sdev->id == starget->id))
fn(sdev, data);
}
}
EXPORT_SYMBOL(starget_for_each_device);
/**
* __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
* @starget: target whose devices we want to iterate over.
* @data: parameter for callback @fn()
* @fn: callback function that is invoked for each device
*
* This traverses over each device of @starget. It does _not_
* take a reference on the scsi_device, so the whole loop must be
* protected by shost->host_lock.
*
* Note: The only reason why drivers would want to use this is because
* they need to access the device list in irq context. Otherwise you
* really want to use starget_for_each_device instead.
**/
void __starget_for_each_device(struct scsi_target *starget, void *data,
void (*fn)(struct scsi_device *, void *))
{
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
struct scsi_device *sdev;
__shost_for_each_device(sdev, shost) {
if ((sdev->channel == starget->channel) &&
(sdev->id == starget->id))
fn(sdev, data);
}
}
EXPORT_SYMBOL(__starget_for_each_device);
/**
* __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
* @starget: SCSI target pointer
* @lun: SCSI Logical Unit Number
*
* Description: Looks up the scsi_device with the specified @lun for a given
* @starget. The returned scsi_device does not have an additional
* reference. You must hold the host's host_lock over this call and
* any access to the returned scsi_device. A scsi_device in state
* SDEV_DEL is skipped.
*
* Note: The only reason why drivers should use this is because
* they need to access the device list in irq context. Otherwise you
* really want to use scsi_device_lookup_by_target instead.
**/
struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
u64 lun)
{
struct scsi_device *sdev;
list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
if (sdev->sdev_state == SDEV_DEL)
continue;
if (sdev->lun ==lun)
return sdev;
}
return NULL;
}
EXPORT_SYMBOL(__scsi_device_lookup_by_target);
/**
* scsi_device_lookup_by_target - find a device given the target
* @starget: SCSI target pointer
* @lun: SCSI Logical Unit Number
*
* Description: Looks up the scsi_device with the specified @lun for a given
* @starget. The returned scsi_device has an additional reference that
* needs to be released with scsi_device_put once you're done with it.
**/
struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
u64 lun)
{
struct scsi_device *sdev;
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
sdev = __scsi_device_lookup_by_target(starget, lun);
if (sdev && scsi_device_get(sdev))
sdev = NULL;
spin_unlock_irqrestore(shost->host_lock, flags);
return sdev;
}
EXPORT_SYMBOL(scsi_device_lookup_by_target);
/**
* __scsi_device_lookup - find a device given the host (UNLOCKED)
* @shost: SCSI host pointer
* @channel: SCSI channel (zero if only one channel)
* @id: SCSI target number (physical unit number)
* @lun: SCSI Logical Unit Number
*
* Description: Looks up the scsi_device with the specified @channel, @id, @lun
* for a given host. The returned scsi_device does not have an additional
* reference. You must hold the host's host_lock over this call and any access
* to the returned scsi_device.
*
* Note: The only reason why drivers would want to use this is because
* they need to access the device list in irq context. Otherwise you
* really want to use scsi_device_lookup instead.
**/
struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
uint channel, uint id, u64 lun)
{
struct scsi_device *sdev;
list_for_each_entry(sdev, &shost->__devices, siblings) {
if (sdev->sdev_state == SDEV_DEL)
continue;
if (sdev->channel == channel && sdev->id == id &&
sdev->lun ==lun)
return sdev;
}
return NULL;
}
EXPORT_SYMBOL(__scsi_device_lookup);
/**
* scsi_device_lookup - find a device given the host
* @shost: SCSI host pointer
* @channel: SCSI channel (zero if only one channel)
* @id: SCSI target number (physical unit number)
* @lun: SCSI Logical Unit Number
*
* Description: Looks up the scsi_device with the specified @channel, @id, @lun
* for a given host. The returned scsi_device has an additional reference that
* needs to be released with scsi_device_put once you're done with it.
**/
struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
uint channel, uint id, u64 lun)
{
struct scsi_device *sdev;
unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
sdev = __scsi_device_lookup(shost, channel, id, lun);
if (sdev && scsi_device_get(sdev))
sdev = NULL;
spin_unlock_irqrestore(shost->host_lock, flags);
return sdev;
}
EXPORT_SYMBOL(scsi_device_lookup);
MODULE_DESCRIPTION("SCSI core");
MODULE_LICENSE("GPL");
module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
/* This should go away in the future, it doesn't do anything anymore */
bool scsi_use_blk_mq = true;
module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO);
static int __init init_scsi(void)
{
int error;
error = scsi_init_queue();
if (error)
return error;
error = scsi_init_procfs();
if (error)
goto cleanup_queue;
error = scsi_init_devinfo();
if (error)
goto cleanup_procfs;
error = scsi_init_hosts();
if (error)
goto cleanup_devlist;
error = scsi_init_sysctl();
if (error)
goto cleanup_hosts;
error = scsi_sysfs_register();
if (error)
goto cleanup_sysctl;
scsi_netlink_init();
printk(KERN_NOTICE "SCSI subsystem initialized\n");
return 0;
cleanup_sysctl:
scsi_exit_sysctl();
cleanup_hosts:
scsi_exit_hosts();
cleanup_devlist:
scsi_exit_devinfo();
cleanup_procfs:
scsi_exit_procfs();
cleanup_queue:
scsi_exit_queue();
printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
-error);
return error;
}
static void __exit exit_scsi(void)
{
scsi_netlink_exit();
scsi_sysfs_unregister();
scsi_exit_sysctl();
scsi_exit_hosts();
scsi_exit_devinfo();
scsi_exit_procfs();
scsi_exit_queue();
}
subsys_initcall(init_scsi);
module_exit(exit_scsi);