![Dan Williams](/assets/img/avatar_default.png)
sd injects and synchronizes probe work on the global kernel-wide domain. This runs into conflict with PM that wants to perform resume actions in async context: [ 494.237079] INFO: task kworker/u:3:554 blocked for more than 120 seconds. [ 494.294396] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 494.360809] kworker/u:3 D 0000000000000000 0 554 2 0x00000000 [ 494.420739] ffff88012e4d3af0 0000000000000046 ffff88013200c160 ffff88012e4d3fd8 [ 494.484392] ffff88012e4d3fd8 0000000000012500 ffff8801394ea0b0 ffff88013200c160 [ 494.548038] ffff88012e4d3ae0 00000000000001e3 ffffffff81a249e0 ffff8801321c5398 [ 494.611685] Call Trace: [ 494.632649] [<ffffffff8149dd25>] schedule+0x5a/0x5c [ 494.674687] [<ffffffff8104b968>] async_synchronize_cookie_domain+0xb6/0x112 [ 494.734177] [<ffffffff810461ff>] ? __init_waitqueue_head+0x50/0x50 [ 494.787134] [<ffffffff8131a224>] ? scsi_remove_target+0x48/0x48 [ 494.837900] [<ffffffff8104b9d9>] async_synchronize_cookie+0x15/0x17 [ 494.891567] [<ffffffff8104ba49>] async_synchronize_full+0x54/0x70 <-- here we wait for async contexts to complete [ 494.943783] [<ffffffff8104b9f5>] ? async_synchronize_full_domain+0x1a/0x1a [ 495.002547] [<ffffffffa00114b1>] sd_remove+0x2c/0xa2 [sd_mod] [ 495.051861] [<ffffffff812fe94f>] __device_release_driver+0x86/0xcf [ 495.104807] [<ffffffff812fe9bd>] device_release_driver+0x25/0x32 <-- here we take device_lock() [ 853.511341] INFO: task kworker/u:4:549 blocked for more than 120 seconds. [ 853.568693] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 853.635119] kworker/u:4 D ffff88013097b5d0 0 549 2 0x00000000 [ 853.695129] ffff880132773c40 0000000000000046 ffff880130790000 ffff880132773fd8 [ 853.758990] ffff880132773fd8 0000000000012500 ffff88013288a0b0 ffff880130790000 [ 853.822796] 0000000000000246 0000000000000040 ffff88013097b5c8 ffff880130790000 [ 853.886633] Call Trace: [ 853.907631] [<ffffffff8149dd25>] schedule+0x5a/0x5c [ 853.949670] [<ffffffff8149cc44>] __mutex_lock_common+0x220/0x351 [ 854.001225] [<ffffffff81304bd7>] ? device_resume+0x58/0x1c4 [ 854.049082] [<ffffffff81304bd7>] ? device_resume+0x58/0x1c4 [ 854.097011] [<ffffffff8149ce48>] mutex_lock_nested+0x2f/0x36 <-- here we wait for device_lock() [ 854.145591] [<ffffffff81304bd7>] device_resume+0x58/0x1c4 [ 854.192066] [<ffffffff81304d61>] async_resume+0x1e/0x45 [ 854.237019] [<ffffffff8104bc93>] async_run_entry_fn+0xc6/0x173 <-- ...while running in async context Provide a 'scsi_sd_probe_domain' so that async probe actions actions can be flushed without regard for the state of PM, and allow for the resume path to handle devices that have transitioned from SDEV_QUIESCE to SDEV_DEL prior to resume. Acked-by: Alan Stern <stern@rowland.harvard.edu> [alan: uplevel scsi_sd_probe_domain, clarify scsi_device_resume] Signed-off-by: Dan Williams <dan.j.williams@intel.com> [jejb: remove unneeded config guards in include file] Signed-off-by: James Bottomley <JBottomley@Parallels.com>
1363 lines
37 KiB
C
1363 lines
37 KiB
C
/*
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* scsi.c Copyright (C) 1992 Drew Eckhardt
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* Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
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* Copyright (C) 2002, 2003 Christoph Hellwig
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*
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* generic mid-level SCSI driver
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* Initial versions: Drew Eckhardt
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* Subsequent revisions: Eric Youngdale
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*
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* <drew@colorado.edu>
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*
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* Bug correction thanks go to :
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* Rik Faith <faith@cs.unc.edu>
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* Tommy Thorn <tthorn>
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* Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
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*
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* Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
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* add scatter-gather, multiple outstanding request, and other
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* enhancements.
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*
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* Native multichannel, wide scsi, /proc/scsi and hot plugging
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* support added by Michael Neuffer <mike@i-connect.net>
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*
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* Added request_module("scsi_hostadapter") for kerneld:
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* (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
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* Bjorn Ekwall <bj0rn@blox.se>
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* (changed to kmod)
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*
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* Major improvements to the timeout, abort, and reset processing,
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* as well as performance modifications for large queue depths by
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* Leonard N. Zubkoff <lnz@dandelion.com>
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*
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* Converted cli() code to spinlocks, Ingo Molnar
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*
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* Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
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*
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* out_of_space hacks, D. Gilbert (dpg) 990608
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/kernel.h>
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#include <linux/timer.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/blkdev.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/completion.h>
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#include <linux/unistd.h>
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#include <linux/spinlock.h>
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#include <linux/kmod.h>
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#include <linux/interrupt.h>
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#include <linux/notifier.h>
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#include <linux/cpu.h>
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#include <linux/mutex.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_dbg.h>
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#include <scsi/scsi_device.h>
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#include <scsi/scsi_driver.h>
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#include <scsi/scsi_eh.h>
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#include <scsi/scsi_host.h>
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#include <scsi/scsi_tcq.h>
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#include "scsi_priv.h"
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#include "scsi_logging.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/scsi.h>
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static void scsi_done(struct scsi_cmnd *cmd);
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/*
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* Definitions and constants.
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*/
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#define MIN_RESET_DELAY (2*HZ)
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/* Do not call reset on error if we just did a reset within 15 sec. */
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#define MIN_RESET_PERIOD (15*HZ)
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/*
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* Note - the initial logging level can be set here to log events at boot time.
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* After the system is up, you may enable logging via the /proc interface.
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*/
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unsigned int scsi_logging_level;
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#if defined(CONFIG_SCSI_LOGGING)
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EXPORT_SYMBOL(scsi_logging_level);
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#endif
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#if IS_ENABLED(CONFIG_PM) || IS_ENABLED(CONFIG_BLK_DEV_SD)
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/* sd and scsi_pm need to coordinate flushing async actions */
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LIST_HEAD(scsi_sd_probe_domain);
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EXPORT_SYMBOL(scsi_sd_probe_domain);
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#endif
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/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
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* You may not alter any existing entry (although adding new ones is
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* encouraged once assigned by ANSI/INCITS T10
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*/
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static const char *const scsi_device_types[] = {
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"Direct-Access ",
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"Sequential-Access",
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"Printer ",
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"Processor ",
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"WORM ",
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"CD-ROM ",
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"Scanner ",
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"Optical Device ",
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"Medium Changer ",
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"Communications ",
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"ASC IT8 ",
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"ASC IT8 ",
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"RAID ",
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"Enclosure ",
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"Direct-Access-RBC",
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"Optical card ",
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"Bridge controller",
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"Object storage ",
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"Automation/Drive ",
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};
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/**
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* scsi_device_type - Return 17 char string indicating device type.
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* @type: type number to look up
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*/
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const char * scsi_device_type(unsigned type)
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{
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if (type == 0x1e)
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return "Well-known LUN ";
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if (type == 0x1f)
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return "No Device ";
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if (type >= ARRAY_SIZE(scsi_device_types))
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return "Unknown ";
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return scsi_device_types[type];
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}
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EXPORT_SYMBOL(scsi_device_type);
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struct scsi_host_cmd_pool {
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struct kmem_cache *cmd_slab;
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struct kmem_cache *sense_slab;
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unsigned int users;
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char *cmd_name;
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char *sense_name;
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unsigned int slab_flags;
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gfp_t gfp_mask;
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};
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static struct scsi_host_cmd_pool scsi_cmd_pool = {
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.cmd_name = "scsi_cmd_cache",
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.sense_name = "scsi_sense_cache",
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.slab_flags = SLAB_HWCACHE_ALIGN,
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};
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static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
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.cmd_name = "scsi_cmd_cache(DMA)",
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.sense_name = "scsi_sense_cache(DMA)",
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.slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
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.gfp_mask = __GFP_DMA,
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};
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static DEFINE_MUTEX(host_cmd_pool_mutex);
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/**
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* scsi_pool_alloc_command - internal function to get a fully allocated command
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* @pool: slab pool to allocate the command from
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* @gfp_mask: mask for the allocation
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*
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* Returns a fully allocated command (with the allied sense buffer) or
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* NULL on failure
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*/
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static struct scsi_cmnd *
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scsi_pool_alloc_command(struct scsi_host_cmd_pool *pool, gfp_t gfp_mask)
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{
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struct scsi_cmnd *cmd;
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cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask);
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if (!cmd)
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return NULL;
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cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab,
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gfp_mask | pool->gfp_mask);
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if (!cmd->sense_buffer) {
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kmem_cache_free(pool->cmd_slab, cmd);
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return NULL;
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}
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return cmd;
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}
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/**
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* scsi_pool_free_command - internal function to release a command
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* @pool: slab pool to allocate the command from
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* @cmd: command to release
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*
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* the command must previously have been allocated by
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* scsi_pool_alloc_command.
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*/
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static void
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scsi_pool_free_command(struct scsi_host_cmd_pool *pool,
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struct scsi_cmnd *cmd)
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{
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if (cmd->prot_sdb)
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kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
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kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
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kmem_cache_free(pool->cmd_slab, cmd);
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}
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/**
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* scsi_host_alloc_command - internal function to allocate command
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* @shost: SCSI host whose pool to allocate from
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* @gfp_mask: mask for the allocation
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*
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* Returns a fully allocated command with sense buffer and protection
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* data buffer (where applicable) or NULL on failure
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*/
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static struct scsi_cmnd *
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scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask)
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{
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struct scsi_cmnd *cmd;
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cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask);
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if (!cmd)
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return NULL;
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if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
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cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
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if (!cmd->prot_sdb) {
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scsi_pool_free_command(shost->cmd_pool, cmd);
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return NULL;
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}
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}
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return cmd;
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}
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/**
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* __scsi_get_command - Allocate a struct scsi_cmnd
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* @shost: host to transmit command
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* @gfp_mask: allocation mask
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*
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* Description: allocate a struct scsi_cmd from host's slab, recycling from the
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* host's free_list if necessary.
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*/
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struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
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{
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struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask);
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if (unlikely(!cmd)) {
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unsigned long flags;
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spin_lock_irqsave(&shost->free_list_lock, flags);
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if (likely(!list_empty(&shost->free_list))) {
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cmd = list_entry(shost->free_list.next,
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struct scsi_cmnd, list);
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list_del_init(&cmd->list);
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}
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spin_unlock_irqrestore(&shost->free_list_lock, flags);
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if (cmd) {
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void *buf, *prot;
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buf = cmd->sense_buffer;
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prot = cmd->prot_sdb;
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memset(cmd, 0, sizeof(*cmd));
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cmd->sense_buffer = buf;
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cmd->prot_sdb = prot;
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}
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}
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return cmd;
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}
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EXPORT_SYMBOL_GPL(__scsi_get_command);
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/**
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* scsi_get_command - Allocate and setup a scsi command block
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* @dev: parent scsi device
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* @gfp_mask: allocator flags
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*
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* Returns: The allocated scsi command structure.
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*/
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struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
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{
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struct scsi_cmnd *cmd;
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/* Bail if we can't get a reference to the device */
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if (!get_device(&dev->sdev_gendev))
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return NULL;
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cmd = __scsi_get_command(dev->host, gfp_mask);
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if (likely(cmd != NULL)) {
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unsigned long flags;
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cmd->device = dev;
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INIT_LIST_HEAD(&cmd->list);
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spin_lock_irqsave(&dev->list_lock, flags);
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list_add_tail(&cmd->list, &dev->cmd_list);
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spin_unlock_irqrestore(&dev->list_lock, flags);
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cmd->jiffies_at_alloc = jiffies;
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} else
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put_device(&dev->sdev_gendev);
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return cmd;
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}
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EXPORT_SYMBOL(scsi_get_command);
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/**
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* __scsi_put_command - Free a struct scsi_cmnd
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* @shost: dev->host
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* @cmd: Command to free
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* @dev: parent scsi device
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*/
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void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd,
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struct device *dev)
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{
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unsigned long flags;
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/* changing locks here, don't need to restore the irq state */
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spin_lock_irqsave(&shost->free_list_lock, flags);
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if (unlikely(list_empty(&shost->free_list))) {
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list_add(&cmd->list, &shost->free_list);
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cmd = NULL;
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}
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spin_unlock_irqrestore(&shost->free_list_lock, flags);
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if (likely(cmd != NULL))
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scsi_pool_free_command(shost->cmd_pool, cmd);
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put_device(dev);
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}
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EXPORT_SYMBOL(__scsi_put_command);
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/**
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* scsi_put_command - Free a scsi command block
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* @cmd: command block to free
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*
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* Returns: Nothing.
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*
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* Notes: The command must not belong to any lists.
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*/
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void scsi_put_command(struct scsi_cmnd *cmd)
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{
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struct scsi_device *sdev = cmd->device;
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unsigned long flags;
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/* serious error if the command hasn't come from a device list */
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spin_lock_irqsave(&cmd->device->list_lock, flags);
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BUG_ON(list_empty(&cmd->list));
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list_del_init(&cmd->list);
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spin_unlock_irqrestore(&cmd->device->list_lock, flags);
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__scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev);
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}
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EXPORT_SYMBOL(scsi_put_command);
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static struct scsi_host_cmd_pool *scsi_get_host_cmd_pool(gfp_t gfp_mask)
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{
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struct scsi_host_cmd_pool *retval = NULL, *pool;
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/*
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* Select a command slab for this host and create it if not
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* yet existent.
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*/
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mutex_lock(&host_cmd_pool_mutex);
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pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool :
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&scsi_cmd_pool;
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if (!pool->users) {
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pool->cmd_slab = kmem_cache_create(pool->cmd_name,
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sizeof(struct scsi_cmnd), 0,
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pool->slab_flags, NULL);
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if (!pool->cmd_slab)
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goto fail;
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pool->sense_slab = kmem_cache_create(pool->sense_name,
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SCSI_SENSE_BUFFERSIZE, 0,
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pool->slab_flags, NULL);
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if (!pool->sense_slab) {
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kmem_cache_destroy(pool->cmd_slab);
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goto fail;
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}
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}
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pool->users++;
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retval = pool;
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fail:
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mutex_unlock(&host_cmd_pool_mutex);
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return retval;
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}
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static void scsi_put_host_cmd_pool(gfp_t gfp_mask)
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{
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struct scsi_host_cmd_pool *pool;
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mutex_lock(&host_cmd_pool_mutex);
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pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool :
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&scsi_cmd_pool;
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/*
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* This may happen if a driver has a mismatched get and put
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* of the command pool; the driver should be implicated in
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* the stack trace
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*/
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BUG_ON(pool->users == 0);
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if (!--pool->users) {
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kmem_cache_destroy(pool->cmd_slab);
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kmem_cache_destroy(pool->sense_slab);
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}
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mutex_unlock(&host_cmd_pool_mutex);
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}
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|
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/**
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* scsi_allocate_command - get a fully allocated SCSI command
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* @gfp_mask: allocation mask
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*
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* This function is for use outside of the normal host based pools.
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* It allocates the relevant command and takes an additional reference
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* on the pool it used. This function *must* be paired with
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* scsi_free_command which also has the identical mask, otherwise the
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* free pool counts will eventually go wrong and you'll trigger a bug.
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*
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* This function should *only* be used by drivers that need a static
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* command allocation at start of day for internal functions.
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*/
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struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask)
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{
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struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask);
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if (!pool)
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return NULL;
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|
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return scsi_pool_alloc_command(pool, gfp_mask);
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}
|
|
EXPORT_SYMBOL(scsi_allocate_command);
|
|
|
|
/**
|
|
* scsi_free_command - free a command allocated by scsi_allocate_command
|
|
* @gfp_mask: mask used in the original allocation
|
|
* @cmd: command to free
|
|
*
|
|
* Note: using the original allocation mask is vital because that's
|
|
* what determines which command pool we use to free the command. Any
|
|
* mismatch will cause the system to BUG eventually.
|
|
*/
|
|
void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd)
|
|
{
|
|
struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask);
|
|
|
|
/*
|
|
* this could trigger if the mask to scsi_allocate_command
|
|
* doesn't match this mask. Otherwise we're guaranteed that this
|
|
* succeeds because scsi_allocate_command must have taken a reference
|
|
* on the pool
|
|
*/
|
|
BUG_ON(!pool);
|
|
|
|
scsi_pool_free_command(pool, cmd);
|
|
/*
|
|
* scsi_put_host_cmd_pool is called twice; once to release the
|
|
* reference we took above, and once to release the reference
|
|
* originally taken by scsi_allocate_command
|
|
*/
|
|
scsi_put_host_cmd_pool(gfp_mask);
|
|
scsi_put_host_cmd_pool(gfp_mask);
|
|
}
|
|
EXPORT_SYMBOL(scsi_free_command);
|
|
|
|
/**
|
|
* scsi_setup_command_freelist - Setup the command freelist for a scsi host.
|
|
* @shost: host to allocate the freelist for.
|
|
*
|
|
* Description: The command freelist protects against system-wide out of memory
|
|
* deadlock by preallocating one SCSI command structure for each host, so the
|
|
* system can always write to a swap file on a device associated with that host.
|
|
*
|
|
* Returns: Nothing.
|
|
*/
|
|
int scsi_setup_command_freelist(struct Scsi_Host *shost)
|
|
{
|
|
struct scsi_cmnd *cmd;
|
|
const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL;
|
|
|
|
spin_lock_init(&shost->free_list_lock);
|
|
INIT_LIST_HEAD(&shost->free_list);
|
|
|
|
shost->cmd_pool = scsi_get_host_cmd_pool(gfp_mask);
|
|
|
|
if (!shost->cmd_pool)
|
|
return -ENOMEM;
|
|
|
|
/*
|
|
* Get one backup command for this host.
|
|
*/
|
|
cmd = scsi_host_alloc_command(shost, gfp_mask);
|
|
if (!cmd) {
|
|
scsi_put_host_cmd_pool(gfp_mask);
|
|
shost->cmd_pool = NULL;
|
|
return -ENOMEM;
|
|
}
|
|
list_add(&cmd->list, &shost->free_list);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* scsi_destroy_command_freelist - Release the command freelist for a scsi host.
|
|
* @shost: host whose freelist is going to be destroyed
|
|
*/
|
|
void scsi_destroy_command_freelist(struct Scsi_Host *shost)
|
|
{
|
|
/*
|
|
* If cmd_pool is NULL the free list was not initialized, so
|
|
* do not attempt to release resources.
|
|
*/
|
|
if (!shost->cmd_pool)
|
|
return;
|
|
|
|
while (!list_empty(&shost->free_list)) {
|
|
struct scsi_cmnd *cmd;
|
|
|
|
cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
|
|
list_del_init(&cmd->list);
|
|
scsi_pool_free_command(shost->cmd_pool, cmd);
|
|
}
|
|
shost->cmd_pool = NULL;
|
|
scsi_put_host_cmd_pool(shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL);
|
|
}
|
|
|
|
#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
|
|
*
|
|
* 3: same as 2 plus dump cmd address
|
|
*
|
|
* 4: same as 3 plus dump extra junk
|
|
*/
|
|
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: ");
|
|
if (level > 2)
|
|
printk("0x%p ", cmd);
|
|
printk("\n");
|
|
scsi_print_command(cmd);
|
|
if (level > 3) {
|
|
printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
|
|
" queuecommand 0x%p\n",
|
|
scsi_sglist(cmd), scsi_bufflen(cmd),
|
|
cmd->device->host->hostt->queuecommand);
|
|
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
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 plus dump cmd address
|
|
*
|
|
* 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)) {
|
|
scmd_printk(KERN_INFO, cmd, "Done: ");
|
|
if (level > 2)
|
|
printk("0x%p ", cmd);
|
|
/*
|
|
* Dump truncated values, so we usually fit within
|
|
* 80 chars.
|
|
*/
|
|
switch (disposition) {
|
|
case SUCCESS:
|
|
printk("SUCCESS\n");
|
|
break;
|
|
case NEEDS_RETRY:
|
|
printk("RETRY\n");
|
|
break;
|
|
case ADD_TO_MLQUEUE:
|
|
printk("MLQUEUE\n");
|
|
break;
|
|
case FAILED:
|
|
printk("FAILED\n");
|
|
break;
|
|
case TIMEOUT_ERROR:
|
|
/*
|
|
* If called via scsi_times_out.
|
|
*/
|
|
printk("TIMEOUT\n");
|
|
break;
|
|
default:
|
|
printk("UNKNOWN\n");
|
|
}
|
|
scsi_print_result(cmd);
|
|
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",
|
|
cmd->device->host->host_busy,
|
|
cmd->device->host->host_failed);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* scsi_cmd_get_serial - Assign a serial number to a command
|
|
* @host: the scsi host
|
|
* @cmd: command to assign serial number to
|
|
*
|
|
* Description: a serial number identifies a request for error recovery
|
|
* and debugging purposes. Protected by the Host_Lock of host.
|
|
*/
|
|
void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
|
|
{
|
|
cmd->serial_number = host->cmd_serial_number++;
|
|
if (cmd->serial_number == 0)
|
|
cmd->serial_number = host->cmd_serial_number++;
|
|
}
|
|
EXPORT_SYMBOL(scsi_cmd_get_serial);
|
|
|
|
/**
|
|
* scsi_dispatch_command - Dispatch a command to the low-level driver.
|
|
* @cmd: command block we are dispatching.
|
|
*
|
|
* Return: nonzero return request was rejected and device's queue needs to be
|
|
* plugged.
|
|
*/
|
|
int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
|
|
{
|
|
struct Scsi_Host *host = cmd->device->host;
|
|
unsigned long timeout;
|
|
int rtn = 0;
|
|
|
|
atomic_inc(&cmd->device->iorequest_cnt);
|
|
|
|
/* check if the device is still usable */
|
|
if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
|
|
/* in SDEV_DEL we error all commands. DID_NO_CONNECT
|
|
* returns an immediate error upwards, and signals
|
|
* that the device is no longer present */
|
|
cmd->result = DID_NO_CONNECT << 16;
|
|
scsi_done(cmd);
|
|
/* return 0 (because the command has been processed) */
|
|
goto out;
|
|
}
|
|
|
|
/* Check to see if the scsi lld made this device blocked. */
|
|
if (unlikely(scsi_device_blocked(cmd->device))) {
|
|
/*
|
|
* in blocked state, the command is just put back on
|
|
* the device queue. The suspend state has already
|
|
* blocked the queue so future requests should not
|
|
* occur until the device transitions out of the
|
|
* suspend state.
|
|
*/
|
|
|
|
scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
|
|
|
|
SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n"));
|
|
|
|
/*
|
|
* NOTE: rtn is still zero here because we don't need the
|
|
* queue to be plugged on return (it's already stopped)
|
|
*/
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* If SCSI-2 or lower, store the LUN value in cmnd.
|
|
*/
|
|
if (cmd->device->scsi_level <= SCSI_2 &&
|
|
cmd->device->scsi_level != SCSI_UNKNOWN) {
|
|
cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
|
|
(cmd->device->lun << 5 & 0xe0);
|
|
}
|
|
|
|
/*
|
|
* We will wait MIN_RESET_DELAY clock ticks after the last reset so
|
|
* we can avoid the drive not being ready.
|
|
*/
|
|
timeout = host->last_reset + MIN_RESET_DELAY;
|
|
|
|
if (host->resetting && time_before(jiffies, timeout)) {
|
|
int ticks_remaining = timeout - jiffies;
|
|
/*
|
|
* NOTE: This may be executed from within an interrupt
|
|
* handler! This is bad, but for now, it'll do. The irq
|
|
* level of the interrupt handler has been masked out by the
|
|
* platform dependent interrupt handling code already, so the
|
|
* sti() here will not cause another call to the SCSI host's
|
|
* interrupt handler (assuming there is one irq-level per
|
|
* host).
|
|
*/
|
|
while (--ticks_remaining >= 0)
|
|
mdelay(1 + 999 / HZ);
|
|
host->resetting = 0;
|
|
}
|
|
|
|
scsi_log_send(cmd);
|
|
|
|
/*
|
|
* Before we queue this command, check if the command
|
|
* length exceeds what the host adapter can handle.
|
|
*/
|
|
if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
|
|
SCSI_LOG_MLQUEUE(3,
|
|
printk("queuecommand : command too long. "
|
|
"cdb_size=%d host->max_cmd_len=%d\n",
|
|
cmd->cmd_len, cmd->device->host->max_cmd_len));
|
|
cmd->result = (DID_ABORT << 16);
|
|
|
|
scsi_done(cmd);
|
|
goto out;
|
|
}
|
|
|
|
if (unlikely(host->shost_state == SHOST_DEL)) {
|
|
cmd->result = (DID_NO_CONNECT << 16);
|
|
scsi_done(cmd);
|
|
} else {
|
|
trace_scsi_dispatch_cmd_start(cmd);
|
|
cmd->scsi_done = scsi_done;
|
|
rtn = host->hostt->queuecommand(host, cmd);
|
|
}
|
|
|
|
if (rtn) {
|
|
trace_scsi_dispatch_cmd_error(cmd, rtn);
|
|
if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
|
|
rtn != SCSI_MLQUEUE_TARGET_BUSY)
|
|
rtn = SCSI_MLQUEUE_HOST_BUSY;
|
|
|
|
scsi_queue_insert(cmd, rtn);
|
|
|
|
SCSI_LOG_MLQUEUE(3,
|
|
printk("queuecommand : request rejected\n"));
|
|
}
|
|
|
|
out:
|
|
SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n"));
|
|
return rtn;
|
|
}
|
|
|
|
/**
|
|
* scsi_done - Enqueue the finished SCSI command into the done queue.
|
|
* @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
|
|
* ownership back to SCSI Core -- i.e. the LLDD has finished with it.
|
|
*
|
|
* Description: This function is the mid-level's (SCSI Core) interrupt routine,
|
|
* which regains ownership of the SCSI command (de facto) from a LLDD, and
|
|
* enqueues the command to the done queue for further processing.
|
|
*
|
|
* This is the producer of the done queue who enqueues at the tail.
|
|
*
|
|
* This function is interrupt context safe.
|
|
*/
|
|
static void scsi_done(struct scsi_cmnd *cmd)
|
|
{
|
|
trace_scsi_dispatch_cmd_done(cmd);
|
|
blk_complete_request(cmd->request);
|
|
}
|
|
|
|
/**
|
|
* 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 which say that the device/host is no longer
|
|
* capable of accepting new commands. These are set in scsi_queue.c
|
|
* for both the queue full condition on a device, and for a
|
|
* host full condition on the host.
|
|
*
|
|
* XXX(hch): What about locking?
|
|
*/
|
|
shost->host_blocked = 0;
|
|
starget->target_blocked = 0;
|
|
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 (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
|
|
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);
|
|
}
|
|
EXPORT_SYMBOL(scsi_finish_command);
|
|
|
|
/**
|
|
* scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
|
|
* @sdev: SCSI Device in question
|
|
* @tagged: Do we use tagged queueing (non-0) or do we treat
|
|
* this device as an untagged device (0)
|
|
* @tags: Number of tags allowed if tagged queueing enabled,
|
|
* or number of commands the low level driver can
|
|
* queue up in non-tagged mode (as per cmd_per_lun).
|
|
*
|
|
* Returns: Nothing
|
|
*
|
|
* Lock Status: None held on entry
|
|
*
|
|
* Notes: Low level drivers may call this at any time and we will do
|
|
* the right thing depending on whether or not the device is
|
|
* currently active and whether or not it even has the
|
|
* command blocks built yet.
|
|
*/
|
|
void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
|
|
{
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* refuse to set tagged depth to an unworkable size
|
|
*/
|
|
if (tags <= 0)
|
|
return;
|
|
|
|
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
|
|
|
|
/*
|
|
* Check to see if the queue is managed by the block layer.
|
|
* If it is, and we fail to adjust the depth, exit.
|
|
*
|
|
* Do not resize the tag map if it is a host wide share bqt,
|
|
* because the size should be the hosts's can_queue. If there
|
|
* is more IO than the LLD's can_queue (so there are not enuogh
|
|
* tags) request_fn's host queue ready check will handle it.
|
|
*/
|
|
if (!sdev->host->bqt) {
|
|
if (blk_queue_tagged(sdev->request_queue) &&
|
|
blk_queue_resize_tags(sdev->request_queue, tags) != 0)
|
|
goto out;
|
|
}
|
|
|
|
sdev->queue_depth = tags;
|
|
switch (tagged) {
|
|
case MSG_ORDERED_TAG:
|
|
sdev->ordered_tags = 1;
|
|
sdev->simple_tags = 1;
|
|
break;
|
|
case MSG_SIMPLE_TAG:
|
|
sdev->ordered_tags = 0;
|
|
sdev->simple_tags = 1;
|
|
break;
|
|
default:
|
|
sdev_printk(KERN_WARNING, sdev,
|
|
"scsi_adjust_queue_depth, bad queue type, "
|
|
"disabled\n");
|
|
case 0:
|
|
sdev->ordered_tags = sdev->simple_tags = 0;
|
|
sdev->queue_depth = tags;
|
|
break;
|
|
}
|
|
out:
|
|
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(scsi_adjust_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;
|
|
if (sdev->last_queue_full_depth < 8) {
|
|
/* Drop back to untagged */
|
|
scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
|
|
return -1;
|
|
}
|
|
|
|
if (sdev->ordered_tags)
|
|
scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
|
|
else
|
|
scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
|
|
return 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 0 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];
|
|
|
|
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 result;
|
|
|
|
/* Sanity check that we got the page back that we asked for */
|
|
if (buffer[1] != page)
|
|
return -EIO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
|
|
/* Ask for all the pages supported by this device */
|
|
result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
|
|
if (result)
|
|
goto fail;
|
|
|
|
/* If the user actually wanted this page, we can skip the rest */
|
|
if (page == 0)
|
|
return 0;
|
|
|
|
for (i = 0; i < min((int)buf[3], buf_len - 4); i++)
|
|
if (buf[i + 4] == page)
|
|
goto found;
|
|
|
|
if (i < buf[3] && i >= buf_len - 4)
|
|
/* 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)
|
|
goto fail;
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
return -EINVAL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
int scsi_device_get(struct scsi_device *sdev)
|
|
{
|
|
if (sdev->sdev_state == SDEV_DEL)
|
|
return -ENXIO;
|
|
if (!get_device(&sdev->sdev_gendev))
|
|
return -ENXIO;
|
|
/* We can fail this if we're doing SCSI operations
|
|
* from module exit (like cache flush) */
|
|
try_module_get(sdev->host->hostt->module);
|
|
|
|
return 0;
|
|
}
|
|
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)
|
|
{
|
|
#ifdef CONFIG_MODULE_UNLOAD
|
|
struct module *module = sdev->host->hostt->module;
|
|
|
|
/* The module refcount will be zero if scsi_device_get()
|
|
* was called from a module removal routine */
|
|
if (module && module_refcount(module) != 0)
|
|
module_put(module);
|
|
#endif
|
|
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,
|
|
uint 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,
|
|
uint 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, uint lun)
|
|
{
|
|
struct scsi_device *sdev;
|
|
|
|
list_for_each_entry(sdev, &shost->__devices, siblings) {
|
|
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, uint 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");
|
|
|
|
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);
|