cregit-Linux how code gets into the kernel

Release 4.7 drivers/scsi/scsi.c

Directory: drivers/scsi
/*
 *  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

/* sd, scsi core and power management need to coordinate flushing async actions */

ASYNC_DOMAIN(scsi_sd_probe_domain);

EXPORT_SYMBOL(scsi_sd_probe_domain);

/*
 * Separate domain (from scsi_sd_probe_domain) to maximize the benefit of
 * 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);


struct scsi_host_cmd_pool {
	
struct kmem_cache	*cmd_slab;
	
struct kmem_cache	*sense_slab;
	
unsigned int		users;
	
char			*cmd_name;
	
char			*sense_name;
	
unsigned int		slab_flags;
	
gfp_t			gfp_mask;
};


static struct scsi_host_cmd_pool scsi_cmd_pool = {
	.cmd_name	= "scsi_cmd_cache",
	.sense_name	= "scsi_sense_cache",
	.slab_flags	= SLAB_HWCACHE_ALIGN,
};


static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
	.cmd_name	= "scsi_cmd_cache(DMA)",
	.sense_name	= "scsi_sense_cache(DMA)",
	.slab_flags	= SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
	.gfp_mask	= __GFP_DMA,
};

static DEFINE_MUTEX(host_cmd_pool_mutex);

/**
 * scsi_host_free_command - internal function to release a command
 * @shost:      host to free the command for
 * @cmd:        command to release
 *
 * the command must previously have been allocated by
 * scsi_host_alloc_command.
 */

static void scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd) { struct scsi_host_cmd_pool *pool = shost->cmd_pool; if (cmd->prot_sdb) kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); kmem_cache_free(pool->sense_slab, cmd->sense_buffer); kmem_cache_free(pool->cmd_slab, cmd); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig1830.00%350.00%
james bottomleyjames bottomley1728.33%116.67%
martin k. petersenmartin k. petersen1525.00%116.67%
hugh dickinshugh dickins1016.67%116.67%
Total60100.00%6100.00%

/** * scsi_host_alloc_command - internal function to allocate command * @shost: SCSI host whose pool to allocate from * @gfp_mask: mask for the allocation * * Returns a fully allocated command with sense buffer and protection * data buffer (where applicable) or NULL on failure */
static struct scsi_cmnd * scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask) { struct scsi_host_cmd_pool *pool = shost->cmd_pool; struct scsi_cmnd *cmd; cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask); if (!cmd) goto fail; cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab, gfp_mask | pool->gfp_mask); if (!cmd->sense_buffer) goto fail_free_cmd; if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask); if (!cmd->prot_sdb) goto fail_free_sense; } return cmd; fail_free_sense: kmem_cache_free(pool->sense_slab, cmd->sense_buffer); fail_free_cmd: kmem_cache_free(pool->cmd_slab, cmd); fail: return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig7350.69%150.00%
martin k. petersenmartin k. petersen7149.31%150.00%
Total144100.00%2100.00%

/** * __scsi_get_command - Allocate a struct scsi_cmnd * @shost: host to transmit command * @gfp_mask: allocation mask * * Description: allocate a struct scsi_cmd from host's slab, recycling from the * host's free_list if necessary. */
static struct scsi_cmnd * __scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) { struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask); if (unlikely(!cmd)) { unsigned long flags; spin_lock_irqsave(&shost->free_list_lock, flags); if (likely(!list_empty(&shost->free_list))) { cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); list_del_init(&cmd->list); } spin_unlock_irqrestore(&shost->free_list_lock, flags); if (cmd) { void *buf, *prot; buf = cmd->sense_buffer; prot = cmd->prot_sdb; memset(cmd, 0, sizeof(*cmd)); cmd->sense_buffer = buf; cmd->prot_sdb = prot; } } return cmd; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig5938.06%325.00%
fujita tomonorifujita tomonori3220.65%18.33%
james bottomleyjames bottomley2314.84%18.33%
martin k. petersenmartin k. petersen2214.19%216.67%
pre-gitpre-git1710.97%433.33%
hugh dickinshugh dickins21.29%18.33%
Total155100.00%12100.00%

/** * scsi_get_command - Allocate and setup a scsi command block * @dev: parent scsi device * @gfp_mask: allocator flags * * Returns: The allocated scsi command structure. */
struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) { struct scsi_cmnd *cmd = __scsi_get_command(dev->host, gfp_mask); unsigned long flags; if (unlikely(cmd == NULL)) return NULL; cmd->device = dev; INIT_LIST_HEAD(&cmd->list); INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); spin_lock_irqsave(&dev->list_lock, flags); list_add_tail(&cmd->list, &dev->cmd_list); spin_unlock_irqrestore(&dev->list_lock, flags); cmd->jiffies_at_alloc = jiffies; return cmd; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig4944.14%323.08%
james bottomleyjames bottomley2926.13%215.38%
pre-gitpre-git109.01%323.08%
hannes reineckehannes reinecke109.01%17.69%
luben tuikovluben tuikov65.41%215.38%
matthew dobsonmatthew dobson65.41%17.69%
al viroal viro10.90%17.69%
Total111100.00%13100.00%

/** * __scsi_put_command - Free a struct scsi_cmnd * @shost: dev->host * @cmd: Command to free */
static void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd) { unsigned long flags; if (unlikely(list_empty(&shost->free_list))) { spin_lock_irqsave(&shost->free_list_lock, flags); if (list_empty(&shost->free_list)) { list_add(&cmd->list, &shost->free_list); cmd = NULL; } spin_unlock_irqrestore(&shost->free_list_lock, flags); } if (likely(cmd != NULL)) scsi_host_free_command(shost, cmd); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig5252.00%430.77%
pre-gitpre-git1818.00%538.46%
fujita tomonorifujita tomonori1111.00%17.69%
doug ledforddoug ledford1010.00%17.69%
james bottomleyjames bottomley99.00%215.38%
Total100100.00%13100.00%

/** * 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) { unsigned long flags; /* serious error if the command hasn't come from a device list */ spin_lock_irqsave(&cmd->device->list_lock, flags); BUG_ON(list_empty(&cmd->list)); list_del_init(&cmd->list); spin_unlock_irqrestore(&cmd->device->list_lock, flags); BUG_ON(delayed_work_pending(&cmd->abort_work)); __scsi_put_command(cmd->device->host, cmd); }

Contributors

PersonTokensPropCommitsCommitProp
fujita tomonorifujita tomonori6682.50%120.00%
hannes reineckehannes reinecke78.75%120.00%
bart van asschebart van assche45.00%120.00%
james bottomleyjames bottomley22.50%120.00%
doug ledforddoug ledford11.25%120.00%
Total80100.00%5100.00%


static struct scsi_host_cmd_pool * scsi_find_host_cmd_pool(struct Scsi_Host *shost) { if (shost->hostt->cmd_size) return shost->hostt->cmd_pool; if (shost->unchecked_isa_dma) return &scsi_cmd_dma_pool; return &scsi_cmd_pool; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig3992.86%266.67%
james bottomleyjames bottomley37.14%133.33%
Total42100.00%3100.00%


static void scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool) { kfree(pool->sense_name); kfree(pool->cmd_name); kfree(pool); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig30100.00%1100.00%
Total30100.00%1100.00%


static struct scsi_host_cmd_pool * scsi_alloc_host_cmd_pool(struct Scsi_Host *shost) { struct scsi_host_template *hostt = shost->hostt; struct scsi_host_cmd_pool *pool; pool = kzalloc(sizeof(*pool), GFP_KERNEL); if (!pool) return NULL; pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->proc_name); pool->sense_name = kasprintf(GFP_KERNEL, "%s_sense", hostt->proc_name); if (!pool->cmd_name || !pool->sense_name) { scsi_free_host_cmd_pool(pool); return NULL; } pool->slab_flags = SLAB_HWCACHE_ALIGN; if (shost->unchecked_isa_dma) { pool->slab_flags |= SLAB_CACHE_DMA; pool->gfp_mask = __GFP_DMA; } if (hostt->cmd_size) hostt->cmd_pool = pool; return pool; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig12689.36%125.00%
juergen grossjuergen gross128.51%125.00%
james bottomleyjames bottomley32.13%250.00%
Total141100.00%4100.00%


static struct scsi_host_cmd_pool * scsi_get_host_cmd_pool(struct Scsi_Host *shost) { struct scsi_host_template *hostt = shost->hostt; struct scsi_host_cmd_pool *retval = NULL, *pool; size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size; /* * Select a command slab for this host and create it if not * yet existent. */ mutex_lock(&host_cmd_pool_mutex); pool = scsi_find_host_cmd_pool(shost); if (!pool) { pool = scsi_alloc_host_cmd_pool(shost); if (!pool) goto out; } if (!pool->users) { pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0, pool->slab_flags, NULL); if (!pool->cmd_slab) goto out_free_pool; pool->sense_slab = kmem_cache_create(pool->sense_name, SCSI_SENSE_BUFFERSIZE, 0, pool->slab_flags, NULL); if (!pool->sense_slab) goto out_free_slab; } pool->users++; retval = pool; out: mutex_unlock(&host_cmd_pool_mutex); return retval; out_free_slab: kmem_cache_destroy(pool->cmd_slab); out_free_pool: if (hostt->cmd_size) { scsi_free_host_cmd_pool(pool); hostt->cmd_pool = NULL; } goto out; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig13264.39%222.22%
james bottomleyjames bottomley4421.46%222.22%
doug ledforddoug ledford157.32%111.11%
juergen grossjuergen gross83.90%111.11%
andrew mortonandrew morton31.46%111.11%
arjan van de venarjan van de ven20.98%111.11%
rob landleyrob landley10.49%111.11%
Total205100.00%9100.00%


static void scsi_put_host_cmd_pool(struct Scsi_Host *shost) { struct scsi_host_template *hostt = shost->hostt; struct scsi_host_cmd_pool *pool; mutex_lock(&host_cmd_pool_mutex); pool = scsi_find_host_cmd_pool(shost); /* * This may happen if a driver has a mismatched get and put * of the command pool; the driver should be implicated in * the stack trace */ BUG_ON(pool->users == 0); if (!--pool->users) { kmem_cache_destroy(pool->cmd_slab); kmem_cache_destroy(pool->sense_slab); if (hostt->cmd_size) { scsi_free_host_cmd_pool(pool); hostt->cmd_pool = NULL; } } mutex_unlock(&host_cmd_pool_mutex); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig4041.24%222.22%
james bottomleyjames bottomley3435.05%222.22%
doug ledforddoug ledford88.25%111.11%
juergen grossjuergen gross88.25%111.11%
fujita tomonorifujita tomonori66.19%222.22%
arjan van de venarjan van de ven11.03%111.11%
Total97100.00%9100.00%

/** * 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) { const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL; struct scsi_cmnd *cmd; spin_lock_init(&shost->free_list_lock); INIT_LIST_HEAD(&shost->free_list); shost->cmd_pool = scsi_get_host_cmd_pool(shost); 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(shost); shost->cmd_pool = NULL; return -ENOMEM; } list_add(&cmd->list, &shost->free_list); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
james bottomleyjames bottomley9282.88%120.00%
christoph hellwigchristoph hellwig1210.81%240.00%
alan d. brunellealan d. brunelle65.41%120.00%
martin k. petersenmartin k. petersen10.90%120.00%
Total111100.00%5100.00%

/** * 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_host_free_command(shost, cmd); } shost->cmd_pool = NULL; scsi_put_host_cmd_pool(shost); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig5063.29%233.33%
doug ledforddoug ledford1215.19%116.67%
alan d. brunellealan d. brunelle911.39%116.67%
fujita tomonorifujita tomonori56.33%116.67%
james bottomleyjames bottomley33.80%116.67%
Total79100.00%6100.00%

#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); } } }

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PersonTokensPropCommitsCommitProp
patrick mansfieldpatrick mansfield5291.23%120.00%
hannes reineckehannes reinecke23.51%240.00%
martin k. petersenmartin k. petersen23.51%120.00%
christoph hellwigchristoph hellwig11.75%120.00%
Total57100.00%5100.00%


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", atomic_read(&cmd->device->host->host_busy), cmd->device->host->host_failed); } } }

Contributors

PersonTokensPropCommitsCommitProp
patrick mansfieldpatrick mansfield10984.50%116.67%
martin k. petersenmartin k. petersen118.53%116.67%
christoph hellwigchristoph hellwig64.65%233.33%
hannes reineckehannes reinecke32.33%233.33%
Total129100.00%6100.00%

#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++; }

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andi kleenandi kleen41100.00%1100.00%
Total41100.00%1100.00%

EXPORT_SYMBOL(scsi_cmd_get_serial); /** * 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 (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); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig10548.39%426.67%
linus torvaldslinus torvalds4721.66%16.67%
james bottomleyjames bottomley198.76%16.67%
pre-gitpre-git198.76%320.00%
mike christiemike christie156.91%16.67%
jeff garzikjeff garzik52.30%16.67%
boaz harroshboaz harrosh31.38%16.67%
patrick mansfieldpatrick mansfield20.92%213.33%
doug ledforddoug ledford20.92%16.67%
Total217100.00%15100.00%

/** * 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(); } return sdev->queue_depth; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig1954.29%450.00%
doug ledforddoug ledford1028.57%112.50%
pre-gitpre-git514.29%225.00%
mike christiemike christie12.86%112.50%
Total35100.00%8100.00%

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); }

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PersonTokensPropCommitsCommitProp
doug ledforddoug ledford5461.36%125.00%
christoph hellwigchristoph hellwig2932.95%250.00%
vasu devvasu dev55.68%125.00%
Total88100.00%4100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
matthew wilcoxmatthew wilcox12885.33%150.00%
hannes reineckehannes reinecke2214.67%150.00%
Total150100.00%2100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
matthew wilcoxmatthew wilcox9765.10%120.00%
james bottomleyjames bottomley3422.82%120.00%
martin k. petersenmartin k. petersen117.38%240.00%
hannes reineckehannes reinecke74.70%120.00%
Total149100.00%5100.00%

EXPORT_SYMBOL_GPL(scsi_get_vpd_page); /** * 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 result, i; int vpd_len = SCSI_VPD_PG_LEN; int pg80_supported = 0; int pg83_supported = 0; unsigned char __rcu *vpd_buf, *orig_vpd_buf = NULL; if (!scsi_device_supports_vpd(sdev)) return; retry_pg0: vpd_buf = kmalloc(vpd_len, GFP_KERNEL); if (!vpd_buf) return; /* Ask for all the pages supported by this device */ result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len); if (result < 0) { kfree(vpd_buf); return; } if (result > vpd_len) { vpd_len = result; kfree(vpd_buf); goto retry_pg0; } for (i = 4; i < result; i++) { if (vpd_buf[i] == 0x80) pg80_supported = 1; if (vpd_buf[i] == 0x83) pg83_supported = 1; } kfree(vpd_buf); vpd_len = SCSI_VPD_PG_LEN; if (pg80_supported) { retry_pg80: vpd_buf = kmalloc(vpd_len, GFP_KERNEL); if (!vpd_buf) return; result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len); if (result < 0) { kfree(vpd_buf); return; } if (result > vpd_len) { vpd_len = result; kfree(vpd_buf); goto retry_pg80; } mutex_lock(&sdev->inquiry_mutex); orig_vpd_buf = sdev->vpd_pg80; sdev->vpd_pg80_len = result; rcu_assign_pointer(sdev->vpd_pg80, vpd_buf); mutex_unlock(&sdev->inquiry_mutex); synchronize_rcu(); if (orig_vpd_buf) { kfree(orig_vpd_buf); orig_vpd_buf = NULL; } vpd_len = SCSI_VPD_PG_LEN; } if (pg83_supported) { retry_pg83: vpd_buf = kmalloc(vpd_len, GFP_KERNEL); if (!vpd_buf) return; result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len); if (result < 0) { kfree(vpd_buf); return; } if (result > vpd_len) { vpd_len = result; kfree(vpd_buf); goto retry_pg83; } mutex_lock(&sdev->inquiry_mutex); orig_vpd_buf = sdev->vpd_pg83; sdev->vpd_pg83_len = result; rcu_assign_pointer(sdev->vpd_pg83, vpd_buf); mutex_unlock(&sdev->inquiry_mutex); synchronize_rcu(); if (orig_vpd_buf) kfree(orig_vpd_buf); } }

Contributors

PersonTokensPropCommitsCommitProp
hannes reineckehannes reinecke413100.00%3100.00%
Total413100.00%3100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
martin k. petersenmartin k. petersen197100.00%2100.00%
Total197100.00%2100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig6179.22%450.00%
mike andersonmike anderson1012.99%112.50%
james bottomleyjames bottomley45.19%225.00%
patrick mansfieldpatrick mansfield22.60%112.50%
Total77100.00%8100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig1344.83%120.00%
james bottomleyjames bottomley827.59%240.00%
mike andersonmike anderson620.69%120.00%
rusty russellrusty russell26.90%120.00%
Total29100.00%5100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig10786.29%466.67%
mike andersonmike anderson1310.48%116.67%
james bottomleyjames bottomley43.23%116.67%
Total124100.00%6100.00%

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); } }

Contributors

PersonTokensPropCommitsCommitProp
james bottomleyjames bottomley84100.00%1100.00%
Total84100.00%1100.00%

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); } }

Contributors

PersonTokensPropCommitsCommitProp
maciej w. rozyckimaciej w. rozycki84100.00%1100.00%
Total84100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
james bottomleyjames bottomley4381.13%133.33%
hannes reineckehannes reinecke1018.87%266.67%
Total53100.00%3100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
james bottomleyjames bottomley8098.77%150.00%
hannes reineckehannes reinecke11.23%150.00%
Total81100.00%2100.00%

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->channel == channel && sdev->id == id && sdev->lun ==lun) return sdev; } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig4979.03%133.33%
mike andersonmike anderson1219.35%133.33%
hannes reineckehannes reinecke11.61%133.33%
Total62100.00%3100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig6888.31%133.33%
mike andersonmike anderson810.39%133.33%
hannes reineckehannes reinecke11.30%133.33%
Total77100.00%3100.00%

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"); #ifdef CONFIG_SCSI_MQ_DEFAULT bool scsi_use_blk_mq = true; #else bool scsi_use_blk_mq = false; #endif 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; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig9672.18%640.00%
james bottomleyjames bottomley1511.28%16.67%
pre-gitpre-git139.77%320.00%
patrick mansfieldpatrick mansfield43.01%213.33%
james smartjames smart32.26%16.67%
mike andersonmike anderson10.75%16.67%
mike sullivanmike sullivan10.75%16.67%
Total133100.00%15100.00%


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(); async_unregister_domain(&scsi_sd_probe_domain); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig1027.78%538.46%
pre-gitpre-git822.22%215.38%
dan williamsdan williams616.67%17.69%
patrick mansfieldpatrick mansfield513.89%215.38%
james smartjames smart38.33%17.69%
mike andersonmike anderson25.56%17.69%
linus torvaldslinus torvalds25.56%17.69%
Total36100.00%13100.00%

subsys_initcall(init_scsi); module_exit(exit_scsi);

Overall Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig139934.42%3021.28%
james bottomleyjames bottomley59114.54%1712.06%
hannes reineckehannes reinecke48011.81%107.09%
martin k. petersenmartin k. petersen3408.36%74.96%
matthew wilcoxmatthew wilcox2305.66%10.71%
patrick mansfieldpatrick mansfield2004.92%53.55%
pre-gitpre-git1393.42%2316.31%
fujita tomonorifujita tomonori1202.95%32.13%
doug ledforddoug ledford1122.76%21.42%
maciej w. rozyckimaciej w. rozycki892.19%10.71%
linus torvaldslinus torvalds631.55%64.26%
mike andersonmike anderson531.30%32.13%
andi kleenandi kleen411.01%10.71%
dan williamsdan williams300.74%42.84%
juergen grossjuergen gross280.69%10.71%
adrian bunkadrian bunk220.54%10.71%
mike christiemike christie160.39%21.42%
alan d. brunellealan d. brunelle150.37%10.71%
rob landleyrob landley120.30%10.71%
hugh dickinshugh dickins120.30%10.71%
jeff garzikjeff garzik100.25%21.42%
rusty russellrusty russell80.20%21.42%
arjan van de venarjan van de ven70.17%10.71%
james smartjames smart60.15%10.71%
luben tuikovluben tuikov60.15%21.42%
keiichiroe tokunagakeiichiroe tokunaga60.15%10.71%
matthew dobsonmatthew dobson60.15%10.71%
vasu devvasu dev50.12%10.71%
bart van asschebart van assche40.10%10.71%
andrew mortonandrew morton40.10%21.42%
boaz harroshboaz harrosh30.07%10.71%
randy dunlaprandy dunlap20.05%21.42%
christoph lameterchristoph lameter20.05%10.71%
al viroal viro20.05%10.71%
mike sullivanmike sullivan10.02%10.71%
bartlomiej zolnierkiewiczbartlomiej zolnierkiewicz10.02%10.71%
Total4065100.00%141100.00%
Directory: drivers/scsi
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