include/scsi/scsi_device.h¶

structscsi_vpd¶

SCSI Vital Product Data

Definition

struct scsi_vpd {  struct rcu_head rcu;  int len;  unsigned char   data[];};

Members

rcu

Forkfree_rcu().

len

Length in bytes ofdata.

data

VPD data as defined in various T10 SCSI standard documents.

shost_for_each_device(sdev,shost)¶

iterate over all devices of a host

Parameters

sdev

thestructscsi_device to use as a cursor

shost

thestructscsi_host to iterate over

Description

Iterator that returns each device attached toshost. This looptakes a reference on each device and releases it at the end. Ifyou break out of the loop, you must call scsi_device_put(sdev).

__shost_for_each_device(sdev,shost)¶

iterate over all devices of a host (UNLOCKED)

Parameters

sdev

thestructscsi_device to use as a cursor

shost

thestructscsi_host to iterate over

Description

Iterator that returns each device attached toshost. It does _not_take a reference on the scsi_device, so the whole loop must beprotected by shost->host_lock.

Note

The only reason to use this is because you need to access thedevice list in interrupt context. Otherwise you really want to useshost_for_each_device instead.

intscsi_device_supports_vpd(struct scsi_device * sdev)¶

test if a device supports VPD pages

Parameters

structscsi_device*sdev

thestructscsi_device to test

Description

If the ‘try_vpd_pages’ flag is set it takes precedence.Otherwise we will assume VPD pages are supported if theSCSI level is at least SPC-3 and ‘skip_vpd_pages’ is not set.

drivers/scsi/scsi.c¶

Main file for the SCSI midlayer.

intscsi_change_queue_depth(struct scsi_device * sdev, int depth)¶

change a device’s queue depth

Parameters

structscsi_device*sdev

SCSI Device in question

intdepth

number of commands allowed to be queued to the driver

Description

Sets the device queue depth and returns the new value.

intscsi_track_queue_full(struct scsi_device * sdev, int depth)¶

track QUEUE_FULL events to adjust queue depth

Parameters

structscsi_device*sdev

SCSI Device in question

intdepth

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 aneed to adjust the queue depth on the device.

Lock Status: None held on entry

Return

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

Notes

Low level drivers may call this at any time and we will do

“The Right Thing.” We are interrupt context safe.

intscsi_get_vpd_page(struct scsi_device * sdev, u8 page, unsigned char * buf, int buf_len)¶

Get Vital Product Data from a SCSI device

Parameters

structscsi_device*sdev

The device to ask

u8page

Which Vital Product Data to return

unsignedchar*buf

where to store the VPD

intbuf_len

number of bytes in the VPD buffer area

Description

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 pointerto a buffer containing the data from that page. The caller isresponsible for callingkfree() on this pointer when it is no longerneeded. If we cannot retrieve the VPD page this routine returnsNULL.

intscsi_report_opcode(struct scsi_device * sdev, unsigned char * buffer, unsigned int len, unsigned char opcode)¶

Find out if a given command opcode is supported

Parameters

structscsi_device*sdev

scsi device to query

unsignedchar*buffer

scratch buffer (must be at least 20 bytes long)

unsignedintlen

length of buffer

unsignedcharopcode

opcode for command to look up

Description

Uses the REPORT SUPPORTED OPERATION CODES to look up the givenopcode. Returns -EINVAL if RSOC fails, 0 if the command opcode isunsupported and 1 if the device claims to support the command.

intscsi_device_get(struct scsi_device * sdev)¶

get an additional reference to a scsi_device

Parameters

structscsi_device*sdev

device to get a reference to

Description

Gets a reference to the scsi_device and increments the use countof the underlying LLDD module. You must hold host_lock of theparent Scsi_Host or already have a reference when calling this.

This will fail if a device is deleted or cancelled, or when the LLD moduleis in the process of being unloaded.

voidscsi_device_put(struct scsi_device * sdev)¶

release a reference to a scsi_device

Parameters

structscsi_device*sdev

device to release a reference on.

Description

Release a reference to the scsi_device and decrements the usecount of the underlying LLDD module. The device is freed once the lastuser vanishes.

voidstarget_for_each_device(struct scsi_target * starget, void * data, void (*fn)(struct scsi_device *, void *))¶

helper to walk all devices of a target

Parameters

structscsi_target*starget

target whose devices we want to iterate over.

void*data

Opaque passed to each function call.

void(*)(structscsi_device*,void*)fn

Function to call on each device

Description

This traverses over each device ofstarget. The devices havea reference that must be released by scsi_host_put when breakingout of the loop.

void__starget_for_each_device(struct scsi_target * starget, void * data, void (*fn)(struct scsi_device *, void *))¶

helper to walk all devices of a target (UNLOCKED)

Parameters

structscsi_target*starget

target whose devices we want to iterate over.

void*data

parameter for callbackfn()

void(*)(structscsi_device*,void*)fn

callback function that is invoked for each device

Description

This traverses over each device ofstarget. It does _not_take a reference on the scsi_device, so the whole loop must beprotected by shost->host_lock.

Note

The only reason why drivers would want to use this is becausethey need to access the device list in irq context. Otherwise youreally want to use starget_for_each_device instead.

struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target * starget, u64 lun)¶

find a device given the target (UNLOCKED)

Parameters

structscsi_target*starget

SCSI target pointer

u64lun

SCSI Logical Unit Number

Description

Looks up the scsi_device with the specifiedlun for a givenstarget. The returned scsi_device does not have an additionalreference. You must hold the host’s host_lock over this call andany access to the returned scsi_device. A scsi_device in stateSDEV_DEL is skipped.

Note

The only reason why drivers should use this is becausethey need to access the device list in irq context. Otherwise youreally want to use scsi_device_lookup_by_target instead.

struct scsi_device *scsi_device_lookup_by_target(struct scsi_target * starget, u64 lun)¶

find a device given the target

Parameters

structscsi_target*starget

SCSI target pointer

u64lun

SCSI Logical Unit Number

Description

Looks up the scsi_device with the specifiedlun for a givenstarget. The returned scsi_device has an additional reference thatneeds 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)¶

find a device given the host (UNLOCKED)

Parameters

structScsi_Host*shost

SCSI host pointer

uintchannel

SCSI channel (zero if only one channel)

uintid

SCSI target number (physical unit number)

u64lun

SCSI Logical Unit Number

Description

Looks up the scsi_device with the specifiedchannel,id,lunfor a given host. The returned scsi_device does not have an additionalreference. You must hold the host’s host_lock over this call and any accessto the returned scsi_device.

Note

The only reason why drivers would want to use this is becausethey need to access the device list in irq context. Otherwise youreally want to use scsi_device_lookup instead.

struct scsi_device *scsi_device_lookup(struct Scsi_Host * shost, uint channel, uint id, u64 lun)¶

find a device given the host

Parameters

structScsi_Host*shost

SCSI host pointer

uintchannel

SCSI channel (zero if only one channel)

uintid

SCSI target number (physical unit number)

u64lun

SCSI Logical Unit Number

Description

Looks up the scsi_device with the specifiedchannel,id,lunfor a given host. The returned scsi_device has an additional reference thatneeds to be released with scsi_device_put once you’re done with it.

drivers/scsi/scsicam.c¶

SCSI Common AccessMethod supportfunctions, for use with HDIO_GETGEO, etc.

unsigned char *scsi_bios_ptable(struct block_device * dev)¶

Read PC partition table out of first sector of device.

Parameters

structblock_device*dev

from this device

Description

Reads the first sector from the device and returns0x42 bytes

starting at offset0x1be.

Return

partition table in kmalloc(GFP_KERNEL) memory, or NULL on error.

boolscsi_partsize(struct block_device * bdev, sector_t capacity, int geom)¶

Parse cylinders/heads/sectors from PC partition table

Parameters

structblock_device*bdev

block device to parse

sector_tcapacity

size of the disk in sectors

intgeom

output in form of [hds, cylinders, sectors]

Description

Determine the BIOS mapping/geometry used to create the partitiontable, storing the results ingeom.

Return

false on failure,true on success.

intscsicam_bios_param(struct block_device * bdev, sector_t capacity, int * ip)¶

Determine geometry of a disk in cylinders/heads/sectors.

Parameters

structblock_device*bdev

which device

sector_tcapacity

size of the disk in sectors

int*ip

return value: ip[0]=heads, ip[1]=sectors, ip[2]=cylinders

Description

determine the BIOS mapping/geometry used for a drive in a

SCSI-CAM system, storing the results in ip as requiredby the HDIO_GETGEO ioctl().

Return

-1 on failure, 0 on success.

drivers/scsi/scsi_error.c¶

Common SCSI error/timeout handling routines.

voidscsi_schedule_eh(struct Scsi_Host * shost)¶

schedule EH for SCSI host

Parameters

structScsi_Host*shost

SCSI host to invoke error handling on.

Description

Schedule SCSI EH without scmd.

intscsi_block_when_processing_errors(struct scsi_device * sdev)¶

Prevent cmds from being queued.

Parameters

structscsi_device*sdev

Device on which we are performing recovery.

Description

We block until the host is out of error recovery, and then check tosee whether the host or the device is offline.

Return value:

0 when dev was taken offline by error recovery. 1 OK to proceed.

intscsi_check_sense(struct scsi_cmnd * scmd)¶

Examine scsi cmd sense

Parameters

structscsi_cmnd*scmd

Cmd to have sense checked.

Description

Return value:

SUCCESS or FAILED or NEEDS_RETRY or ADD_TO_MLQUEUE

Notes

When a deferred error is detected the current command hasnot been executed and needs retrying.

voidscsi_eh_prep_cmnd(struct scsi_cmnd * scmd, struct scsi_eh_save * ses, unsigned char * cmnd, int cmnd_size, unsigned sense_bytes)¶

Save a scsi command info as part of error recovery

Parameters

structscsi_cmnd*scmd

SCSI command structure to hijack

structscsi_eh_save*ses

structure to save restore information

unsignedchar*cmnd

CDB to send. Can be NULL if no new cmnd is needed

intcmnd_size

size in bytes ofcmnd (must be <= BLK_MAX_CDB)

unsignedsense_bytes

size of sense data to copy. or 0 (if != 0cmnd is ignored)

Description

This function is used to save a scsi command information before re-executionas part of the error recovery process. Ifsense_bytes is 0 the commandsent must be one that does not transfer any data. Ifsense_bytes != 0cmnd is ignored and this functions sets up a REQUEST_SENSE commandand cmnd buffers to readsense_bytes intoscmd->sense_buffer.

voidscsi_eh_restore_cmnd(struct scsi_cmnd * scmd, struct scsi_eh_save * ses)¶

Restore a scsi command info as part of error recovery

Parameters

structscsi_cmnd*scmd

SCSI command structure to restore

structscsi_eh_save*ses

saved information from a coresponding call to scsi_eh_prep_cmnd

Description

Undo any damage done by abovescsi_eh_prep_cmnd().

voidscsi_eh_finish_cmd(struct scsi_cmnd * scmd, struct list_head * done_q)¶

Handle a cmd that eh is finished with.

Parameters

structscsi_cmnd*scmd

Original SCSI cmd that eh has finished.

structlist_head*done_q

Queue for processed commands.

Notes

We don’t want to use the normal command completion while we are arestill handling errors - it may cause other commands to be queued,and that would disturb what we are doing. Thus we really want tokeep a list of pending commands for final completion, and once weare ready to leave error handling we handle completion for real.

intscsi_eh_get_sense(struct list_head * work_q, struct list_head * done_q)¶

Get device sense data.

Parameters

structlist_head*work_q

Queue of commands to process.

structlist_head*done_q

Queue of processed commands.

Description

See if we need to request sense information. if so, then get itnow, so we have a better idea of what to do.

Notes

This has the unfortunate side effect that if a shost adapter doesnot automatically request sense information, we end up shuttingit down before we request it.

All drivers should request sense information internally these days,so for now all I have to say is tough noogies if you end up in here.

XXX: Long term this code should go away, but that needs an audit of

all LLDDs first.

voidscsi_eh_ready_devs(struct Scsi_Host * shost, struct list_head * work_q, struct list_head * done_q)¶

check device ready state and recover if not.

Parameters

structScsi_Host*shost

host to be recovered.

structlist_head*work_q

list_head for pending commands.

structlist_head*done_q

list_head for processed commands.

voidscsi_eh_flush_done_q(struct list_head * done_q)¶

finish processed commands or retry them.

Parameters

structlist_head*done_q

list_head of processed commands.

boolscsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len, u64 * info_out)¶

get information field from sense data (either fixed or descriptor format)

Parameters

constu8*sense_buffer

byte array of sense data

intsb_len

number of valid bytes in sense_buffer

u64*info_out

pointer to 64 integer where 8 or 4 byte informationfield will be placed if found.

Description

Return value:

true if information field found, false if not found.

drivers/scsi/scsi_devinfo.c¶

Manage scsi_dev_info_list, which tracks blacklisted and whitelisteddevices.

intscsi_dev_info_list_add(int compatible, char * vendor, char * model, char * strflags, blist_flags_t flags)¶

add one dev_info list entry.

Parameters

intcompatible

if true, null terminate short strings. Otherwise space pad.

char*vendor

vendor string

char*model

model (product) string

char*strflags

integer string

blist_flags_tflags

if strflags NULL, use this flag value

Description

Create and add one dev_info entry forvendor,model,strflags orflag. Ifcompatible, add to the tail of the list, do not spacepad, and set devinfo->compatible. The scsi_static_device_list entriesare added withcompatible 1 andclfags NULL.

Return

0 OK, -error on failure.

struct scsi_dev_info_list *scsi_dev_info_list_find(const char * vendor, const char * model, enum scsi_devinfo_key key)¶

find a matching dev_info list entry.

Parameters

constchar*vendor

full vendor string

constchar*model

full model (product) string

enumscsi_devinfo_keykey

specify list to use

Description

Finds the first dev_info entry matchingvendor,modelin list specified bykey.

Return

pointer to matching entry, or ERR_PTR on failure.

intscsi_dev_info_list_add_str(char * dev_list)¶

parse dev_list and add to the scsi_dev_info_list.

Parameters

char*dev_list

string of device flags to add

Description

Parse dev_list, and add entries to the scsi_dev_info_list.dev_list is of the form “vendor:product:flag,vendor:product:flag”.dev_list is modified via strsep. Can be called for command lineaddition, for proc or mabye a sysfs interface.

Return

0 if OK, -error on failure.

blist_flags_tscsi_get_device_flags(struct scsi_device * sdev, const unsigned char * vendor, const unsigned char * model)¶

get device specific flags from the dynamic device list.

Parameters

structscsi_device*sdev

scsi_device to get flags for

constunsignedchar*vendor

vendor name

constunsignedchar*model

model name

Description

Search the global scsi_dev_info_list (specified by list zero)for an entry matchingvendor andmodel, if found, return thematching flags value, else return the host or global defaultsettings. Called during scan time.

voidscsi_exit_devinfo(void)¶

remove /proc/scsi/device_info & the scsi_dev_info_list

Parameters

void

no arguments

intscsi_init_devinfo(void)¶

set up the dynamic device list.

Parameters

void

no arguments

Description

Add command line entries from scsi_dev_flags, then addscsi_static_device_list entries to the scsi device info list.

drivers/scsi/scsi_ioctl.c¶

Handle ioctl() calls for SCSI devices.

intscsi_ioctl(struct scsi_device * sdev, int cmd, void __user * arg)¶

Dispatch ioctl to scsi device

Parameters

structscsi_device*sdev

scsi device receiving ioctl

intcmd

which ioctl is it

void__user*arg

data associated with ioctl

Description

Thescsi_ioctl() function differs from most ioctls in that itdoes not take a major/minor number as the dev field. Rather, it takesa pointer to astructscsi_device.

drivers/scsi/scsi_lib.c¶

SCSI queuing library.

int__scsi_execute(struct scsi_device * sdev, const unsigned char * cmd, int data_direction, void * buffer, unsigned bufflen, unsigned char * sense, struct scsi_sense_hdr * sshdr, int timeout, int retries, u64 flags, req_flags_t rq_flags, int * resid)¶

insert request and wait for the result

Parameters

structscsi_device*sdev

scsi device

constunsignedchar*cmd

scsi command

intdata_direction

data direction

void*buffer

data buffer

unsignedbufflen

len of buffer

unsignedchar*sense

optional sense buffer

structscsi_sense_hdr*sshdr

optional decoded sense header

inttimeout

request timeout in seconds

intretries

number of times to retry request

u64flags

flags for ->cmd_flags

req_flags_trq_flags

flags for ->rq_flags

int*resid

optional residual length

Description

Returns the scsi_cmnd result field if a command was executed, or a negativeLinux error code if we didn’t get that far.

blk_status_tscsi_init_io(struct scsi_cmnd * cmd)¶

SCSI I/O initialization function.

Parameters

structscsi_cmnd*cmd

command descriptor we wish to initialize

Return

• BLK_STS_OK - on success
• BLK_STS_RESOURCE - if the failure is retryable
• BLK_STS_IOERR - if the failure is fatal

struct scsi_device *scsi_device_from_queue(struct request_queue * q)¶

return sdev associated with a request_queue

Parameters

structrequest_queue*q

The request queue to return the sdev from

Description

Return the sdev associated with a request queue or NULL if therequest_queue does not reference a SCSI device.

voidscsi_block_requests(struct Scsi_Host * shost)¶

Utility function used by low-level drivers to prevent further commands from being queued to the device.

Parameters

structScsi_Host*shost

host in question

Description

There is no timer nor any other means by which the requests get unblockedother than the low-level driver callingscsi_unblock_requests().

voidscsi_unblock_requests(struct Scsi_Host * shost)¶

Utility function used by low-level drivers to allow further commands to be queued to the device.

Parameters

structScsi_Host*shost

host in question

Description

There is no timer nor any other means by which the requests get unblockedother than the low-level driver callingscsi_unblock_requests(). This is doneas an API function so that changes to the internals of the scsi mid-layerwon’t require wholesale changes to drivers that use this feature.

intscsi_mode_select(struct scsi_device * sdev, int pf, int sp, int modepage, unsigned char * buffer, int len, int timeout, int retries, struct scsi_mode_data * data, struct scsi_sense_hdr * sshdr)¶

issue a mode select

Parameters

structscsi_device*sdev

SCSI device to be queried

intpf

Page format bit (1 == standard, 0 == vendor specific)

intsp

Save page bit (0 == don’t save, 1 == save)

intmodepage

mode page being requested

unsignedchar*buffer

request buffer (may not be smaller than eight bytes)

intlen

length of request buffer.

inttimeout

command timeout

intretries

number of retries before failing

structscsi_mode_data*data

returns a structure abstracting the mode header data

structscsi_sense_hdr*sshdr

place to put sense data (or NULL if no sense to be collected).must be SCSI_SENSE_BUFFERSIZE big.

Returns zero if successful; negative error number or scsistatus on error

intscsi_mode_sense(struct scsi_device * sdev, int dbd, int modepage, unsigned char * buffer, int len, int timeout, int retries, struct scsi_mode_data * data, struct scsi_sense_hdr * sshdr)¶

issue a mode sense, falling back from 10 to six bytes if necessary.

Parameters

structscsi_device*sdev

SCSI device to be queried

intdbd

set if mode sense will allow block descriptors to be returned

intmodepage

mode page being requested

unsignedchar*buffer

request buffer (may not be smaller than eight bytes)

intlen

length of request buffer.

inttimeout

command timeout

intretries

number of retries before failing

structscsi_mode_data*data

returns a structure abstracting the mode header data

structscsi_sense_hdr*sshdr

place to put sense data (or NULL if no sense to be collected).must be SCSI_SENSE_BUFFERSIZE big.

Returns zero if unsuccessful, or the header offset (either 4or 8 depending on whether a six or ten byte command wasissued) if successful.

intscsi_test_unit_ready(struct scsi_device * sdev, int timeout, int retries, struct scsi_sense_hdr * sshdr)¶

test if unit is ready

Parameters

structscsi_device*sdev

scsi device to change the state of.

inttimeout

command timeout

intretries

number of retries before failing

structscsi_sense_hdr*sshdr

outpout pointer for decoded sense information.

Returns zero if unsuccessful or an error if TUR failed. Forremovable media, UNIT_ATTENTION sets ->changed flag.

intscsi_device_set_state(struct scsi_device * sdev, enum scsi_device_state state)¶

Take the given device through the device state model.

Parameters

structscsi_device*sdev

scsi device to change the state of.

enumscsi_device_statestate

state to change to.

Returns zero if successful or an error if the requestedtransition is illegal.

voidsdev_evt_send(struct scsi_device * sdev, struct scsi_event * evt)¶

send asserted event to uevent thread

Parameters

structscsi_device*sdev

scsi_device event occurred on

structscsi_event*evt

event to send

Assert scsi device event asynchronously.

struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, gfp_t gfpflags)¶

allocate a new scsi event

Parameters

enumscsi_device_eventevt_type

type of event to allocate

gfp_tgfpflags

GFP flags for allocation

Allocates and returns a new scsi_event.

voidsdev_evt_send_simple(struct scsi_device * sdev, enum scsi_device_event evt_type, gfp_t gfpflags)¶

send asserted event to uevent thread

Parameters

structscsi_device*sdev

scsi_device event occurred on

enumscsi_device_eventevt_type

type of event to send

gfp_tgfpflags

GFP flags for allocation

Assert scsi device event asynchronously, given an event type.

intscsi_device_quiesce(struct scsi_device * sdev)¶

Block user issued commands.

Parameters

structscsi_device*sdev

scsi device to quiesce.

This works by trying to transition to the SDEV_QUIESCE state(which must be a legal transition). When the device is in thisstate, only special requests will be accepted, all others willbe deferred. Since special requests may also be requeued requests,a successful return doesn’t guarantee the device will betotally quiescent.

Must be called with user context, may sleep.

Returns zero if unsuccessful or an error if not.

voidscsi_device_resume(struct scsi_device * sdev)¶

Restart user issued commands to a quiesced device.

Parameters

structscsi_device*sdev

scsi device to resume.

Moves the device from quiesced back to running and restarts thequeues.

Must be called with user context, may sleep.

intscsi_internal_device_block_nowait(struct scsi_device * sdev)¶

try to transition to the SDEV_BLOCK state

Parameters

structscsi_device*sdev

device to block

Description

Pause SCSI command processing on the specified device. Does not sleep.

Returns zero if successful or a negative error code upon failure.

Notes

This routine transitions the device to the SDEV_BLOCK state (which must bea legal transition). When the device is in this state, command processingis paused until the device leaves the SDEV_BLOCK state. See alsoscsi_internal_device_unblock_nowait().

intscsi_internal_device_unblock_nowait(struct scsi_device * sdev, enum scsi_device_state new_state)¶

resume a device after a block request

Parameters

structscsi_device*sdev

device to resume

enumscsi_device_statenew_state

state to set the device to after unblocking

Description

Restart the device queue for a previously suspended SCSI device. Does notsleep.

Returns zero if successful or a negative error code upon failure.

Notes

This routine transitions the device to the SDEV_RUNNING state or to one ofthe offline states (which must be a legal transition) allowing the midlayerto goose the queue for this device.

void *scsi_kmap_atomic_sg(struct scatterlist * sgl, int sg_count, size_t * offset, size_t * len)¶

find and atomically map an sg-elemnt

Parameters

structscatterlist*sgl

scatter-gather list

intsg_count

number of segments in sg

size_t*offset

offset in bytes into sg, on return offset into the mapped area

size_t*len

bytes to map, on return number of bytes mapped

Description

Returns virtual address of the start of the mapped page

voidscsi_kunmap_atomic_sg(void * virt)¶

atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg

Parameters

void*virt

virtual address to be unmapped

intscsi_vpd_lun_id(struct scsi_device * sdev, char * id, size_t id_len)¶

return a unique device identification

Parameters

structscsi_device*sdev

SCSI device

char*id

buffer for the identification

size_tid_len

length of the buffer

Description

Copies a unique device identification intoid basedon the information in the VPD page 0x83 of the device.The string will be formatted as a SCSI name string.

Returns the length of the identification or error on failure.If the identifier is longer than the supplied buffer the actualidentifier length is returned and the buffer is not zero-padded.

drivers/scsi/scsi_lib_dma.c¶

SCSI library functions depending on DMA (map and unmap scatter-gatherlists).

intscsi_dma_map(struct scsi_cmnd * cmd)¶

perform DMA mapping against command’s sg lists

Parameters

structscsi_cmnd*cmd

scsi command

Description

Returns the number of sg lists actually used, zero if the sg listsis NULL, or -ENOMEM if the mapping failed.

voidscsi_dma_unmap(struct scsi_cmnd * cmd)¶

unmap command’s sg lists mapped by scsi_dma_map

Parameters

structscsi_cmnd*cmd

scsi command

drivers/scsi/scsi_proc.c¶

The functions in this file provide an interface between the PROC filesystem and the SCSI device drivers It is mainly used for debugging,statistics and to pass information directly to the lowlevel driver. I.E.plumbing to manage /proc/scsi/*

voidscsi_proc_hostdir_add(struct scsi_host_template * sht)¶

Create directory in /proc for a scsi host

Parameters

structscsi_host_template*sht

owner of this directory

Description

Sets sht->proc_dir to the new directory.

voidscsi_proc_hostdir_rm(struct scsi_host_template * sht)¶

remove directory in /proc for a scsi host

Parameters

structscsi_host_template*sht

owner of directory

voidscsi_proc_host_add(struct Scsi_Host * shost)¶

Add entry for this host to appropriate /proc dir

Parameters

structScsi_Host*shost

host to add

voidscsi_proc_host_rm(struct Scsi_Host * shost)¶

remove this host’s entry from /proc

Parameters

structScsi_Host*shost

which host

intproc_print_scsidevice(structdevice * dev, void * data)¶

return data about this host

Parameters

structdevice*dev

A scsi device

void*data

structseq_file to output to.

Description

prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,and revision.

intscsi_add_single_device(uint host, uint channel, uint id, uint lun)¶

Respond to user request to probe for/add device

Parameters

uinthost

user-supplied decimal integer

uintchannel

user-supplied decimal integer

uintid

user-supplied decimal integer

uintlun

user-supplied decimal integer

Description

called by writing “scsi add-single-device” to /proc/scsi/scsi.

doesscsi_host_lookup() and either user_scan() if that transporttype supports it, or else scsi_scan_host_selected()

Note

this seems to be aimed exclusively at SCSI parallel busses.

intscsi_remove_single_device(uint host, uint channel, uint id, uint lun)¶

Respond to user request to remove a device

Parameters

uinthost

user-supplied decimal integer

uintchannel

user-supplied decimal integer

uintid

user-supplied decimal integer

uintlun

user-supplied decimal integer

Description

called by writing “scsi remove-single-device” to/proc/scsi/scsi. Does ascsi_device_lookup() andscsi_remove_device()

ssize_tproc_scsi_write(struct file * file, const char __user * buf, size_t length, loff_t * ppos)¶

handle writes to /proc/scsi/scsi

Parameters

structfile*file

not used

constchar__user*buf

buffer to write

size_tlength

length of buf, at most PAGE_SIZE

loff_t*ppos

not used

Description

this provides a legacy mechanism to add or remove devices byHost, Channel, ID, and Lun. To use,“echo ‘scsi add-single-device 0 1 2 3’ > /proc/scsi/scsi” or“echo ‘scsi remove-single-device 0 1 2 3’ > /proc/scsi/scsi” with“0 1 2 3” replaced by the Host, Channel, Id, and Lun.

Note

this seems to be aimed at parallel SCSI. Most modern busses (USB,SATA, Firewire, Fibre Channel, etc) dynamically assign these values toprovide a unique identifier and nothing more.

intproc_scsi_open(struct inode * inode, struct file * file)¶

glue function

Parameters

structinode*inode

not used

structfile*file

passed to single_open()

Description

Associates proc_scsi_show with this file

intscsi_init_procfs(void)¶

create scsi and scsi/scsi in procfs

Parameters

void

no arguments

voidscsi_exit_procfs(void)¶

Remove scsi/scsi and scsi from procfs

Parameters

void

no arguments

drivers/scsi/scsi_netlink.c¶

Infrastructure to provide async events from transports to userspace vianetlink, using a single NETLINK_SCSITRANSPORT protocol for alltransports. Seethe original patchsubmission formore details.

voidscsi_nl_rcv_msg(structsk_buff * skb)¶

Receive message handler.

Parameters

structsk_buff*skb

socket receive buffer

Description

Extracts message from a receive buffer.

Validates message header and calls appropriate transport message handler

voidscsi_netlink_init(void)¶

Called by SCSI subsystem to initialize the SCSI transport netlink interface

Parameters

void

no arguments

voidscsi_netlink_exit(void)¶

Called by SCSI subsystem to disable the SCSI transport netlink interface

Parameters

void

no arguments

drivers/scsi/scsi_scan.c¶

Scan a host to determine which (if any) devices are attached. Thegeneral scanning/probing algorithm is as follows, exceptions are made toit depending on device specific flags, compilation options, and globalvariable (boot or module load time) settings. A specific LUN is scannedvia an INQUIRY command; if the LUN has a device attached, a scsi_deviceis allocated and setup for it. For every id of every channel on thegiven host, start by scanning LUN 0. Skip hosts that don’t respond atall to a scan of LUN 0. Otherwise, if LUN 0 has a device attached,allocate and setup a scsi_device for it. If target is SCSI-3 or up,issue a REPORT LUN, and scan all of the LUNs returned by the REPORT LUN;else, sequentially scan LUNs up until some maximum is reached, or a LUNis seen that cannot have a device attached to it.

intscsi_complete_async_scans(void)¶

Wait for asynchronous scans to complete

Parameters

void

no arguments

Description

When this function returns, any host which started scanning beforethis function was called will have finished its scan. Hosts whichstarted scanning after this function was called may or may not havefinished.

voidscsi_unlock_floptical(struct scsi_device * sdev, unsigned char * result)¶

unlock device via a special MODE SENSE command

Parameters

structscsi_device*sdev

scsi device to send command to

unsignedchar*result

area to store the result of the MODE SENSE

Description

Send a vendor specific MODE SENSE (not a MODE SELECT) command.Called for BLIST_KEY devices.

struct scsi_device *scsi_alloc_sdev(struct scsi_target * starget, u64 lun, void * hostdata)¶

allocate and setup a scsi_Device

Parameters

structscsi_target*starget

which target to allocate ascsi_device for

u64lun

which lun

void*hostdata

usually NULL and set by ->slave_alloc instead

Description

Allocate, initialize for io, and return a pointer to a scsi_Device.Stores theshost,channel,id, andlun in the scsi_Device, andadds scsi_Device to the appropriate list.

Return value:

scsi_Device pointer, or NULL on failure.

voidscsi_target_reap_ref_release(struct kref * kref)¶

remove target from visibility

Parameters

structkref*kref

the reap_ref in the target being released

Description

Called on last put of reap_ref, which is the indication that no deviceunder this target is visible anymore, so render the target invisible insysfs. Note: we have to be in user context here because the target reapsshould be done in places where the scsi device visibility is being removed.

struct scsi_target *scsi_alloc_target(structdevice * parent, int channel, uint id)¶

allocate a new or find an existing target

Parameters

structdevice*parent

parent of the target (need not be a scsi host)

intchannel

target channel number (zero if no channels)

uintid

target id number

Description

Return an existing target if one exists, provided it hasn’t alreadygone into STARGET_DEL state, otherwise allocate a new target.

The target is returned with an incremented reference, so the calleris responsible for both reaping and doing a last put

voidscsi_target_reap(struct scsi_target * starget)¶

check to see if target is in use and destroy if not

Parameters

structscsi_target*starget

target to be checked

Description

This is used after removing a LUN or doing a last put of the targetit checks atomically that nothing is using the target and removesit if so.

intscsi_probe_lun(struct scsi_device * sdev, unsigned char * inq_result, int result_len, blist_flags_t * bflags)¶

probe a single LUN using a SCSI INQUIRY

Parameters

structscsi_device*sdev

scsi_device to probe

unsignedchar*inq_result

area to store the INQUIRY result

intresult_len

len of inq_result

blist_flags_t*bflags

store any bflags found here

Description

Probe the lun associated withreq using a standard SCSI INQUIRY;

If the INQUIRY is successful, zero is returned and theINQUIRY data is ininq_result; the scsi_level and INQUIRY lengthare copied to the scsi_device any flags value is stored in*bflags.

intscsi_add_lun(struct scsi_device * sdev, unsigned char * inq_result, blist_flags_t * bflags, int async)¶

allocate and fully initialze a scsi_device

Parameters

structscsi_device*sdev

holds information to be stored in the new scsi_device

unsignedchar*inq_result

holds the result of a previous INQUIRY to the LUN

blist_flags_t*bflags

black/white list flag

intasync

1 if this device is being scanned asynchronously

Description

Initialize the scsi_devicesdev. Optionally set fields basedon values in*bflags.

Return

SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_deviceSCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized

unsigned char *scsi_inq_str(unsigned char * buf, unsigned char * inq, unsigned first, unsigned end)¶

print INQUIRY data from min to max index, strip trailing whitespace

Parameters

unsignedchar*buf

Output buffer with at least end-first+1 bytes of space

unsignedchar*inq

Inquiry buffer (input)

unsignedfirst

Offset of string into inq

unsignedend

Index after last character in inq

intscsi_probe_and_add_lun(struct scsi_target * starget, u64 lun, blist_flags_t * bflagsp, struct scsi_device ** sdevp, enum scsi_scan_mode rescan, void * hostdata)¶

probe a LUN, if a LUN is found add it

Parameters

structscsi_target*starget

pointer to target device structure

u64lun

LUN of target device

blist_flags_t*bflagsp

store bflags here if not NULL

structscsi_device**sdevp

probe the LUN corresponding to this scsi_device

enumscsi_scan_moderescan

if not equal to SCSI_SCAN_INITIAL skip some code onlyneeded on first scan

void*hostdata

passed toscsi_alloc_sdev()

Description

Call scsi_probe_lun, if a LUN with an attached device is found,allocate and set it up by calling scsi_add_lun.

Return

• SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device

• SCSI_SCAN_TARGET_PRESENT: target responded, but no device is

  attached at the LUN

• SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized

voidscsi_sequential_lun_scan(struct scsi_target * starget, blist_flags_t bflags, int scsi_level, enum scsi_scan_mode rescan)¶

sequentially scan a SCSI target

Parameters

structscsi_target*starget

pointer to target structure to scan

blist_flags_tbflags

black/white list flag for LUN 0

intscsi_level

Which version of the standard does this device adhere to

enumscsi_scan_moderescan

passed to scsi_probe_add_lun()

Description

Generally, scan from LUN 1 (LUN 0 is assumed to already have beenscanned) to some maximum lun until a LUN is found with no deviceattached. Use the bflags to figure out any oddities.

Modifies sdevscan->lun.

intscsi_report_lun_scan(struct scsi_target * starget, blist_flags_t bflags, enum scsi_scan_mode rescan)¶

Scan using SCSI REPORT LUN results

Parameters

structscsi_target*starget

which target

blist_flags_tbflags

Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN

enumscsi_scan_moderescan

nonzero if we can skip code only needed on first scan

Description

Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.

If BLINK_REPORTLUN2 is set, scan a target that supports more than 8LUNs even if it’s older than SCSI-3.If BLIST_NOREPORTLUN is set, return 1 always.If BLIST_NOLUN is set, return 0 always.If starget->no_report_luns is set, return 1 always.

Return

0: scan completed (or no memory, so further scanning is futile)1: could not scan with REPORT LUN

struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host * shost)¶

prepare for an async scan

Parameters

structScsi_Host*shost

the host which will be scanned

Return

a cookie to be passed toscsi_finish_async_scan()

Description

Tells the midlayer this host is going to do an asynchronous scan.It reserves the host’s position in the scanning list and ensuresthat other asynchronous scans started after this one won’t affect theordering of the discovered devices.

voidscsi_finish_async_scan(struct async_scan_data * data)¶

asynchronous scan has finished

Parameters

structasync_scan_data*data

cookie returned from earlier call toscsi_prep_async_scan()

Description

All the devices currently attached to this host have been found.This function announces all the devices it has found to the restof the system.

drivers/scsi/scsi_sysctl.c¶

Set up the sysctl entry: “/dev/scsi/logging_level”(DEV_SCSI_LOGGING_LEVEL) which sets/returns scsi_logging_level.

drivers/scsi/scsi_sysfs.c¶

SCSI sysfs interface routines.

voidscsi_remove_device(struct scsi_device * sdev)¶

unregister a device from the scsi bus

Parameters

structscsi_device*sdev

scsi_device to unregister

voidscsi_remove_target(structdevice * dev)¶

try to remove a target and all its devices

Parameters

structdevice*dev

generic starget or parent of generic stargets to be removed

Note

This is slightly racy. It is possible that if the userrequests the addition of another device then the target won’t beremoved.

drivers/scsi/hosts.c¶

mid to lowlevel SCSI driver interface

voidscsi_remove_host(struct Scsi_Host * shost)¶

remove a scsi host

Parameters

structScsi_Host*shost

a pointer to a scsi host to remove

intscsi_add_host_with_dma(struct Scsi_Host * shost, structdevice * dev, structdevice * dma_dev)¶

add a scsi host with dma device

Parameters

structScsi_Host*shost

scsi host pointer to add

structdevice*dev

a struct device of type scsi class

structdevice*dma_dev

dma device for the host

Note

You rarely need to worry about this unless you’re in avirtualised host environments, so use the simpler scsi_add_host()function instead.

Description

Return value:

0 on success / != 0 for error

struct Scsi_Host *scsi_host_alloc(struct scsi_host_template * sht, int privsize)¶

register a scsi host adapter instance.

Parameters

structscsi_host_template*sht

pointer to scsi host template

intprivsize

extra bytes to allocate for driver

Note

Allocate a new Scsi_Host and perform basic initialization.The host is not published to the scsi midlayer until scsi_add_hostis called.

Description

Return value:

Pointer to a new Scsi_Host

struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)¶

get a reference to a Scsi_Host by host no

Parameters

unsignedshorthostnum

host number to locate

Description

Return value:

A pointer to located Scsi_Host or NULL.

The caller must do ascsi_host_put() to drop the referencethatscsi_host_get() took. Theput_device() below droppedthe reference fromclass_find_device().

struct Scsi_Host *scsi_host_get(struct Scsi_Host * shost)¶

inc a Scsi_Host ref count

Parameters

structScsi_Host*shost

Pointer to Scsi_Host to inc.

intscsi_host_busy(struct Scsi_Host * shost)¶

Return the host busy counter

Parameters

structScsi_Host*shost

Pointer to Scsi_Host to inc.

voidscsi_host_put(struct Scsi_Host * shost)¶

dec a Scsi_Host ref count

Parameters

structScsi_Host*shost

Pointer to Scsi_Host to dec.

intscsi_queue_work(struct Scsi_Host * shost, struct work_struct * work)¶

Queue work to the Scsi_Host workqueue.

Parameters

structScsi_Host*shost

Pointer to Scsi_Host.

structwork_struct*work

Work to queue for execution.

Description

Return value:

1 - work queued for execution0 - work is already queued-EINVAL - work queue doesn’t exist

voidscsi_flush_work(struct Scsi_Host * shost)¶

Flush a Scsi_Host’s workqueue.

Parameters

structScsi_Host*shost

Pointer to Scsi_Host.

voidscsi_host_complete_all_commands(struct Scsi_Host * shost, int status)¶

Terminate all running commands

Parameters

structScsi_Host*shost

Scsi Host on which commands should be terminated

intstatus

Status to be set for the terminated commands

Description

There is no protection against modification of the numberof outstanding commands. It is the responsibility of thecaller to ensure that concurrent I/O submission and/orcompletion is stopped when calling this function.

voidscsi_host_busy_iter(struct Scsi_Host * shost, bool (*fn)(struct scsi_cmnd *, void *, bool), void * priv)¶

Iterate over all busy commands

Parameters

structScsi_Host*shost

Pointer to Scsi_Host.

bool(*)(structscsi_cmnd*,void*,bool)fn

Function to call on each busy command

void*priv

Data pointer passed tofn

Description

If locking against concurrent command completions is requiredithas to be provided by the caller

drivers/scsi/scsi_common.c¶

general support functions

const char *scsi_device_type(unsigned type)¶

Return 17-char string indicating device type.

Parameters

unsignedtype

type number to look up

u64scsilun_to_int(struct scsi_lun * scsilun)¶

convert a scsi_lun to an int

Parameters

structscsi_lun*scsilun

struct scsi_lun to be converted.

Description

Convertscsilun from a struct scsi_lun to a four-byte host byte-orderedinteger, and return the result. The caller must check fortruncation before using this function.

Notes

For a description of the LUN format, post SCSI-3 see the SCSIArchitecture Model, for SCSI-3 see the SCSI Controller Commands.

Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this functionreturns the integer: 0x0b03d204

This encoding will return a standard integer LUN for LUNs smallerthan 256, which typically use a single level LUN structure withaddressing method 0.

voidint_to_scsilun(u64 lun, struct scsi_lun * scsilun)¶

reverts an int into a scsi_lun

Parameters

u64lun

integer to be reverted

structscsi_lun*scsilun

struct scsi_lun to be set.

Description

Reverts the functionality of the scsilun_to_int, which packedan 8-byte lun value into an int. This routine unpacks the intback into the lun value.

Notes

Given an integer : 0x0b03d204, this function returns astruct scsi_lun of: d2 04 0b 03 00 00 00 00

boolscsi_normalize_sense(const u8 * sense_buffer, int sb_len, struct scsi_sense_hdr * sshdr)¶

normalize main elements from either fixed or descriptor sense data format into a common format.

Parameters

constu8*sense_buffer

byte array containing sense data returned by device

intsb_len

number of valid bytes in sense_buffer

structscsi_sense_hdr*sshdr

pointer to instance of structure that commonelements are written to.

Notes

The “main elements” from sense data are: response_code, sense_key,asc, ascq and additional_length (only for descriptor format).

Typically this function can be called after a device hasresponded to a SCSI command with the CHECK_CONDITION status.

Description

Return value:

true if valid sense data information found, else false;

const u8 *scsi_sense_desc_find(const u8 * sense_buffer, int sb_len, int desc_type)¶

search for a given descriptor type in descriptor sense data format.

Parameters

constu8*sense_buffer

byte array of descriptor format sense data

intsb_len

number of valid bytes in sense_buffer

intdesc_type

value of descriptor type to find(e.g. 0 -> information)

Notes

only valid when sense data is in descriptor format

Description

Return value:

pointer to start of (first) descriptor if found else NULL

voidscsi_build_sense_buffer(int desc, u8 * buf, u8 key, u8 asc, u8 ascq)¶

build sense data in a buffer

Parameters

intdesc

Sense format (non-zero == descriptor format,0 == fixed format)

u8*buf

Where to build sense data

u8key

Sense key

u8asc

Additional sense code

u8ascq

Additional sense code qualifier

intscsi_set_sense_information(u8 * buf, int buf_len, u64 info)¶

set the information field in a formatted sense data buffer

Parameters

u8*buf

Where to build sense data

intbuf_len

buffer length

u64info

64-bit information value to be set

Description

Return value:

0 on success or -EINVAL for invalid sense buffer length

intscsi_set_sense_field_pointer(u8 * buf, int buf_len, u16 fp, u8 bp, bool cd)¶

set the field pointer sense key specific information in a formatted sense data buffer

Parameters

u8*buf

Where to build sense data

intbuf_len

buffer length

u16fp

field pointer to be set

u8bp

bit pointer to be set

boolcd

command/data bit

Description

Return value:

0 on success or -EINVAL for invalid sense buffer length

Fibre Channel transport¶

The file drivers/scsi/scsi_transport_fc.c defines transport attributesfor Fibre Channel.

u32fc_get_event_number(void)¶

Obtain the next sequential FC event number

Parameters

void

no arguments

Notes

We could have inlined this, but it would have required fc_event_seq tobe exposed. For now, live with the subroutine call.Atomic used to avoid lock/unlock…

voidfc_host_post_fc_event(struct Scsi_Host * shost, u32 event_number, enum fc_host_event_code event_code, u32 data_len, char * data_buf, u64 vendor_id)¶

routine to do the work of posting an event on an fc_host.

Parameters

structScsi_Host*shost

host the event occurred on

u32event_number

fc event number obtained from get_fc_event_number()

enumfc_host_event_codeevent_code

fc_host event being posted

u32data_len

amount, in bytes, of event data

char*data_buf

pointer to event data

u64vendor_id

value for Vendor id

Notes

This routine assumes no locks are held on entry.

voidfc_host_post_event(struct Scsi_Host * shost, u32 event_number, enum fc_host_event_code event_code, u32 event_data)¶

called to post an even on an fc_host.

Parameters

structScsi_Host*shost

host the event occurred on

u32event_number

fc event number obtained from get_fc_event_number()

enumfc_host_event_codeevent_code

fc_host event being posted

u32event_data

32bits of data for the event being posted

Notes

This routine assumes no locks are held on entry.

voidfc_host_post_vendor_event(struct Scsi_Host * shost, u32 event_number, u32 data_len, char * data_buf, u64 vendor_id)¶

called to post a vendor unique event on an fc_host

Parameters

structScsi_Host*shost

host the event occurred on

u32event_number

fc event number obtained from get_fc_event_number()

u32data_len

amount, in bytes, of vendor unique data

char*data_buf

pointer to vendor unique data

u64vendor_id

Vendor id

Notes

This routine assumes no locks are held on entry.

voidfc_host_fpin_rcv(struct Scsi_Host * shost, u32 fpin_len, char * fpin_buf)¶

routine to process a received FPIN.

Parameters

structScsi_Host*shost

host the FPIN was received on

u32fpin_len

length of FPIN payload, in bytes

char*fpin_buf

pointer to FPIN payload

Notes

This routine assumes no locks are held on entry.

enum blk_eh_timer_returnfc_eh_timed_out(struct scsi_cmnd * scmd)¶

FC Transport I/O timeout intercept handler

Parameters

structscsi_cmnd*scmd

The SCSI command which timed out

Description

This routine protects against error handlers getting invoked while arport is in a blocked state, typically due to a temporarily loss ofconnectivity. If the error handlers are allowed to proceed, requeststo abort i/o, reset the target, etc will likely fail as there is no wayto communicate with the device to perform the requested function. Thesefailures may result in the midlayer taking the device offline, requiringmanual intervention to restore operation.

This routine, called whenever an i/o times out, validates the state ofthe underlying rport. If the rport is blocked, it returnsEH_RESET_TIMER, which will continue to reschedule the timeout.Eventually, either the device will return, or devloss_tmo will fire,and when the timeout then fires, it will be handled normally.If the rport is not blocked, normal error handling continues.

Notes

This routine assumes no locks are held on entry.

voidfc_remove_host(struct Scsi_Host * shost)¶

called to terminate any fc_transport-related elements for a scsi host.

Parameters

structScsi_Host*shost

WhichScsi_Host

Description

This routine is expected to be called immediately preceding thea driver’s call toscsi_remove_host().

WARNING: A driver utilizing the fc_transport, which fails to call

this routine prior toscsi_remove_host(), will leave danglingobjects in /sys/class/fc_remote_ports. Access to any of theseobjects can result in a system crash !!!

Notes

This routine assumes no locks are held on entry.

struct fc_rport *fc_remote_port_add(struct Scsi_Host * shost, int channel, struct fc_rport_identifiers * ids)¶

notify fc transport of the existence of a remote FC port.

Parameters

structScsi_Host*shost

scsi host the remote port is connected to.

intchannel

Channel on shost port connected to.

structfc_rport_identifiers*ids

The world wide names, fc address, and FC4 portroles for the remote port.

Description

The LLDD calls this routine to notify the transport of the existenceof a remote port. The LLDD provides the unique identifiers (wwpn,wwn)of the port, it’s FC address (port_id), and the FC4 roles that areactive for the port.

For ports that are FCP targets (aka scsi targets), the FC transportmaintains consistent target id bindings on behalf of the LLDD.A consistent target id binding is an assignment of a target id toa remote port identifier, which persists while the scsi host isattached. The remote port can disappear, then later reappear, andit’s target id assignment remains the same. This allows for shiftsin FC addressing (if binding by wwpn or wwnn) with no apparentchanges to the scsi subsystem which is based on scsi host number andtarget id values. Bindings are only valid during the attachment ofthe scsi host. If the host detaches, then later re-attaches, targetid bindings may change.

This routine is responsible for returning a remote port structure.The routine will search the list of remote ports it maintainsinternally on behalf of consistent target id mappings. If found, theremote port structure will be reused. Otherwise, a new remote portstructure will be allocated.

Whenever a remote port is allocated, a new fc_remote_port classdevice is created.

Should not be called from interrupt context.

Notes

This routine assumes no locks are held on entry.

voidfc_remote_port_delete(struct fc_rport * rport)¶

notifies the fc transport that a remote port is no longer in existence.

Parameters

structfc_rport*rport

The remote port that no longer exists

Description

The LLDD calls this routine to notify the transport that a remoteport is no longer part of the topology. Note: Although a portmay no longer be part of the topology, it may persist in the remoteports displayed by the fc_host. We do this under 2 conditions:

1. If the port was a scsi target, we delay its deletion by “blocking” it.This allows the port to temporarily disappear, then reappear withoutdisrupting the SCSI device tree attached to it. During the “blocked”period the port will still exist.
2. If the port was a scsi target and disappears for longer than weexpect, we’ll delete the port and the tear down the SCSI device treeattached to it. However, we want to semi-persist the target id assignedto that port if it eventually does exist. The port structure willremain (although with minimal information) so that the target idbindings also remain.

If the remote port is not an FCP Target, it will be fully torn downand deallocated, including the fc_remote_port class device.

If the remote port is an FCP Target, the port will be placed in atemporary blocked state. From the LLDD’s perspective, the rport nolonger exists. From the SCSI midlayer’s perspective, the SCSI targetexists, but all sdevs on it are blocked from further I/O. The followingis then expected.

If the remote port does not return (signaled by a LLDD call tofc_remote_port_add()) within the dev_loss_tmo timeout, then thescsi target is removed - killing all outstanding i/o and removing thescsi devices attached to it. The port structure will be marked NotPresent and be partially cleared, leaving only enough information torecognize the remote port relative to the scsi target id binding ifit later appears. The port will remain as long as there is a validbinding (e.g. until the user changes the binding type or unloads thescsi host with the binding).

If the remote port returns within the dev_loss_tmo value (and matchesaccording to the target id binding type), the port structure will bereused. If it is no longer a SCSI target, the target will be torndown. If it continues to be a SCSI target, then the target will beunblocked (allowing i/o to be resumed), and a scan will be activatedto ensure that all luns are detected.

Called from normal process context only - cannot be called from interrupt.

Notes

This routine assumes no locks are held on entry.

voidfc_remote_port_rolechg(struct fc_rport * rport, u32 roles)¶

notifies the fc transport that the roles on a remote may have changed.

Parameters

structfc_rport*rport

The remote port that changed.

u32roles

New roles for this port.

Description

The LLDD calls this routine to notify the transport that theroles on a remote port may have changed. The largest effect of this isif a port now becomes a FCP Target, it must be allocated ascsi target id. If the port is no longer a FCP target, anyscsi target id value assigned to it will persist in case therole changes back to include FCP Target. No changes in the scsimidlayer will be invoked if the role changes (in the expectationthat the role will be resumed. If it doesn’t normal error processingwill take place).

Should not be called from interrupt context.

Notes

This routine assumes no locks are held on entry.

intfc_block_rport(struct fc_rport * rport)¶

Block SCSI eh thread for blocked fc_rport.

Parameters

structfc_rport*rport

Remote port that scsi_eh is trying to recover.

Description

This routine can be called from a FC LLD scsi_eh callback. Itblocks the scsi_eh thread until the fc_rport leaves theFC_PORTSTATE_BLOCKED, or the fast_io_fail_tmo fires. This isnecessary to avoid the scsi_eh failing recovery actions for blockedrports which would lead to offlined SCSI devices.

Return

0 if the fc_rport left the state FC_PORTSTATE_BLOCKED.

FAST_IO_FAIL if the fast_io_fail_tmo fired, this should bepassed back to scsi_eh.

intfc_block_scsi_eh(struct scsi_cmnd * cmnd)¶

Block SCSI eh thread for blocked fc_rport

Parameters

structscsi_cmnd*cmnd

SCSI command that scsi_eh is trying to recover

Description

This routine can be called from a FC LLD scsi_eh callback. Itblocks the scsi_eh thread until the fc_rport leaves theFC_PORTSTATE_BLOCKED, or the fast_io_fail_tmo fires. This isnecessary to avoid the scsi_eh failing recovery actions for blockedrports which would lead to offlined SCSI devices.

Return

0 if the fc_rport left the state FC_PORTSTATE_BLOCKED.

FAST_IO_FAIL if the fast_io_fail_tmo fired, this should bepassed back to scsi_eh.

struct fc_vport *fc_vport_create(struct Scsi_Host * shost, int channel, struct fc_vport_identifiers * ids)¶

Admin App or LLDD requests creation of a vport

Parameters

structScsi_Host*shost

scsi host the virtual port is connected to.

intchannel

channel on shost port connected to.

structfc_vport_identifiers*ids

The world wide names, FC4 port roles, etc forthe virtual port.

Notes

This routine assumes no locks are held on entry.

intfc_vport_terminate(struct fc_vport * vport)¶

Admin App or LLDD requests termination of a vport

Parameters

structfc_vport*vport

fc_vport to be terminated

Description

Calls the LLDD vport_delete() function, then deallocates and removesthe vport from the shost and object tree.

Notes

This routine assumes no locks are held on entry.

iSCSI transport class¶

The file drivers/scsi/scsi_transport_iscsi.c defines transportattributes for the iSCSI class, which sends SCSI packets over TCP/IPconnections.

struct iscsi_bus_flash_session *iscsi_create_flashnode_sess(struct Scsi_Host * shost, int index, struct iscsi_transport * transport, int dd_size)¶

Add flashnode session entry in sysfs

Parameters

structScsi_Host*shost

pointer to host data

intindex

index of flashnode to add in sysfs

structiscsi_transport*transport

pointer to transport data

intdd_size

total size to allocate

Description

Adds a sysfs entry for the flashnode session attributes

Return

pointer to allocated flashnode sess on successNULL on failure

struct iscsi_bus_flash_conn *iscsi_create_flashnode_conn(struct Scsi_Host * shost, struct iscsi_bus_flash_session * fnode_sess, struct iscsi_transport * transport, int dd_size)¶

Add flashnode conn entry in sysfs

Parameters

structScsi_Host*shost

pointer to host data

structiscsi_bus_flash_session*fnode_sess

pointer to the parent flashnode session entry

structiscsi_transport*transport

pointer to transport data

intdd_size

total size to allocate

Description

Adds a sysfs entry for the flashnode connection attributes

Return

pointer to allocated flashnode conn on successNULL on failure

structdevice *iscsi_find_flashnode_sess(struct Scsi_Host * shost, void * data, int (*fn)(structdevice *dev, void *data))¶

finds flashnode session entry

Parameters

structScsi_Host*shost

pointer to host data

void*data

pointer to data containing value to use for comparison

int(*)(structdevice*dev,void*data)fn

function pointer that does actual comparison

Description

Finds the flashnode session object comparing the data passed using logicdefined in passed function pointer

Return

pointer to found flashnode session device object on successNULL on failure

structdevice *iscsi_find_flashnode_conn(struct iscsi_bus_flash_session * fnode_sess)¶

finds flashnode connection entry

Parameters

structiscsi_bus_flash_session*fnode_sess

pointer to parent flashnode session entry

Description

Finds the flashnode connection object comparing the data passed using logicdefined in passed function pointer

Return

pointer to found flashnode connection device object on successNULL on failure

voidiscsi_destroy_flashnode_sess(struct iscsi_bus_flash_session * fnode_sess)¶

destroy flashnode session entry

Parameters

structiscsi_bus_flash_session*fnode_sess

pointer to flashnode session entry to be destroyed

Description

Deletes the flashnode session entry and all children flashnode connectionentries from sysfs

voidiscsi_destroy_all_flashnode(struct Scsi_Host * shost)¶

destroy all flashnode session entries

Parameters

structScsi_Host*shost

pointer to host data

Description

Destroys all the flashnode session entries and all corresponding childrenflashnode connection entries from sysfs

intiscsi_scan_finished(struct Scsi_Host * shost, unsigned long time)¶

helper to report when running scans are done

Parameters

structScsi_Host*shost

scsi host

unsignedlongtime

scan run time

Description

This function can be used by drives like qla4xxx to report to the scsilayer when the scans it kicked off at module load time are done.

intiscsi_block_scsi_eh(struct scsi_cmnd * cmd)¶

block scsi eh until session state has transistioned

Parameters

structscsi_cmnd*cmd

scsi cmd passed to scsi eh handler

Description

If the session is down this function will wait for the recoverytimer to fire or for the session to be logged back in. If therecovery timer fires then FAST_IO_FAIL is returned. The callershould pass this error value to the scsi eh.

voidiscsi_unblock_session(struct iscsi_cls_session * session)¶

set a session as logged in and start IO.

Parameters

structiscsi_cls_session*session

iscsi session

Description

Mark a session as ready to accept IO.

struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host * shost, struct iscsi_transport * transport, int dd_size, unsigned int target_id)¶

create iscsi class session

Parameters

structScsi_Host*shost

scsi host

structiscsi_transport*transport

iscsi transport

intdd_size

private driver data size

unsignedinttarget_id

which target

Description

This can be called from a LLD or iscsi_transport.

struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session * session, int dd_size, uint32_t cid)¶

create iscsi class connection

Parameters

structiscsi_cls_session*session

iscsi cls session

intdd_size

private driver data size

uint32_tcid

connection id

Description

This can be called from a LLD or iscsi_transport. The connectionis child of the session so cid must be unique for all connectionson the session.

Since we do not support MCS, cid will normally be zero. In some casesfor software iscsi we could be trying to preallocate a connection structin which case there could be two connection structs and cid would benon-zero.

intiscsi_destroy_conn(struct iscsi_cls_conn * conn)¶

destroy iscsi class connection

Parameters

structiscsi_cls_conn*conn

iscsi cls session

Description

This can be called from a LLD or iscsi_transport.

intiscsi_session_event(struct iscsi_cls_session * session, enum iscsi_uevent_e event)¶

send session destr. completion event

Parameters

structiscsi_cls_session*session

iscsi class session

enumiscsi_uevent_eevent

type of event

Serial Attached SCSI (SAS) transport class¶

The file drivers/scsi/scsi_transport_sas.c defines transportattributes for Serial Attached SCSI, a variant of SATA aimed at largehigh-end systems.

The SAS transport class contains common code to deal with SAS HBAs, anaproximated representation of SAS topologies in the driver model, andvarious sysfs attributes to expose these topologies and managementinterfaces to userspace.

In addition to the basic SCSI core objects this transport classintroduces two additional intermediate objects: The SAS PHY asrepresented by struct sas_phy defines an “outgoing” PHY on a SAS HBA orExpander, and the SAS remote PHY represented by struct sas_rphy definesan “incoming” PHY on a SAS Expander or end device. Note that this ispurely a software concept, the underlying hardware for a PHY and aremote PHY is the exactly the same.

There is no concept of a SAS port in this code, users can see what PHYsform a wide port based on the port_identifier attribute, which is thesame for all PHYs in a port.

voidsas_remove_children(structdevice * dev)¶

tear down a devices SAS data structures

Parameters

structdevice*dev

device belonging to the sas object

Description

Removes all SAS PHYs and remote PHYs for a given object

voidsas_remove_host(struct Scsi_Host * shost)¶

tear down a Scsi_Host’s SAS data structures

Parameters

structScsi_Host*shost

Scsi Host that is torn down

Description

Removes all SAS PHYs and remote PHYs for a given Scsi_Host and remove theScsi_Host as well.

Note

Do not callscsi_remove_host() on the Scsi_Host any more, as it isalready removed.

u64sas_get_address(struct scsi_device * sdev)¶

return the SAS address of the device

Parameters

structscsi_device*sdev

scsi device

Description

Returns the SAS address of the scsi device

unsigned intsas_tlr_supported(struct scsi_device * sdev)¶

checking TLR bit in vpd 0x90

Parameters

structscsi_device*sdev

scsi device struct

Description

Check Transport Layer Retries are supported or not.If vpd page 0x90 is present, TRL is supported.

voidsas_disable_tlr(struct scsi_device * sdev)¶

setting TLR flags

Parameters

structscsi_device*sdev

scsi device struct

Description

Seting tlr_enabled flag to 0.

voidsas_enable_tlr(struct scsi_device * sdev)¶

setting TLR flags

Parameters

structscsi_device*sdev

scsi device struct

Description

Seting tlr_enabled flag 1.

struct sas_phy *sas_phy_alloc(structdevice * parent, int number)¶

allocates and initialize a SAS PHY structure

Parameters

structdevice*parent

Parent device

intnumber

Phy index

Description

Allocates an SAS PHY structure. It will be added in the device treebelow the device specified byparent, which has to be either a Scsi_Hostor sas_rphy.

Return

SAS PHY allocated orNULL if the allocation failed.

intsas_phy_add(struct sas_phy * phy)¶

add a SAS PHY to the device hierarchy

Parameters

structsas_phy*phy

The PHY to be added

Description

Publishes a SAS PHY to the rest of the system.

voidsas_phy_free(struct sas_phy * phy)¶

free a SAS PHY

Parameters

structsas_phy*phy

SAS PHY to free

Description

Frees the specified SAS PHY.

Note

This function must only be called on a PHY that has notsuccessfully been added usingsas_phy_add().

voidsas_phy_delete(struct sas_phy * phy)¶

remove SAS PHY

Parameters

structsas_phy*phy

SAS PHY to remove

Description

Removes the specified SAS PHY. If the SAS PHY has anassociated remote PHY it is removed before.

intscsi_is_sas_phy(const structdevice * dev)¶

check if a struct device represents a SAS PHY

Parameters

conststructdevice*dev

device to check

Return

1 if the device represents a SAS PHY,0 else

intsas_port_add(struct sas_port * port)¶

add a SAS port to the device hierarchy

Parameters

structsas_port*port

port to be added

Description

publishes a port to the rest of the system

voidsas_port_free(struct sas_port * port)¶

free a SAS PORT

Parameters

structsas_port*port

SAS PORT to free

Description

Frees the specified SAS PORT.

Note

This function must only be called on a PORT that has notsuccessfully been added usingsas_port_add().

voidsas_port_delete(struct sas_port * port)¶

remove SAS PORT

Parameters

structsas_port*port

SAS PORT to remove

Description

Removes the specified SAS PORT. If the SAS PORT has anassociated phys, unlink them from the port as well.

intscsi_is_sas_port(const structdevice * dev)¶

check if a struct device represents a SAS port

Parameters

conststructdevice*dev

device to check

Return

1 if the device represents a SAS Port,0 else

struct sas_phy *sas_port_get_phy(struct sas_port * port)¶

try to take a reference on a port member

Parameters

structsas_port*port

port to check

voidsas_port_add_phy(struct sas_port * port, struct sas_phy * phy)¶

add another phy to a port to form a wide port

Parameters

structsas_port*port

port to add the phy to

structsas_phy*phy

phy to add

Description

When a port is initially created, it is empty (has no phys). Allports must have at least one phy to operated, and all wide portsmust have at least two. The current code makes no differencebetween ports and wide ports, but the only object that can beconnected to a remote device is a port, so ports must be formed onall devices with phys if they’re connected to anything.

voidsas_port_delete_phy(struct sas_port * port, struct sas_phy * phy)¶

remove a phy from a port or wide port

Parameters

structsas_port*port

port to remove the phy from

structsas_phy*phy

phy to remove

Description

This operation is used for tearing down ports again. It must bedone to every port or wide port before calling sas_port_delete.

struct sas_rphy *sas_end_device_alloc(struct sas_port * parent)¶

allocate an rphy for an end device

Parameters

structsas_port*parent

which port

Description

Allocates an SAS remote PHY structure, connected toparent.

Return

SAS PHY allocated orNULL if the allocation failed.

struct sas_rphy *sas_expander_alloc(struct sas_port * parent, enum sas_device_type type)¶

allocate an rphy for an end device

Parameters

structsas_port*parent

which port

enumsas_device_typetype

SAS_EDGE_EXPANDER_DEVICE or SAS_FANOUT_EXPANDER_DEVICE

Description

Allocates an SAS remote PHY structure, connected toparent.

Return

SAS PHY allocated orNULL if the allocation failed.

intsas_rphy_add(struct sas_rphy * rphy)¶

add a SAS remote PHY to the device hierarchy

Parameters

structsas_rphy*rphy

The remote PHY to be added

Description

Publishes a SAS remote PHY to the rest of the system.

voidsas_rphy_free(struct sas_rphy * rphy)¶

free a SAS remote PHY

Parameters

structsas_rphy*rphy

SAS remote PHY to free

Description

Frees the specified SAS remote PHY.

Note

This function must only be called on a remotePHY that has not successfully been added usingsas_rphy_add() (or has beensas_rphy_remove()’d)

voidsas_rphy_delete(struct sas_rphy * rphy)¶

remove and free SAS remote PHY

Parameters

structsas_rphy*rphy

SAS remote PHY to remove and free

Description

Removes the specified SAS remote PHY and frees it.

voidsas_rphy_unlink(struct sas_rphy * rphy)¶

unlink SAS remote PHY

Parameters

structsas_rphy*rphy

SAS remote phy to unlink from its parent port

Description

Removes port reference to an rphy

voidsas_rphy_remove(struct sas_rphy * rphy)¶

remove SAS remote PHY

Parameters

structsas_rphy*rphy

SAS remote phy to remove

Description

Removes the specified SAS remote PHY.

intscsi_is_sas_rphy(const structdevice * dev)¶

check if a struct device represents a SAS remote PHY

Parameters

conststructdevice*dev

device to check

Return

1 if the device represents a SAS remote PHY,0 else

struct scsi_transport_template *sas_attach_transport(struct sas_function_template * ft)¶

instantiate SAS transport template

Parameters

structsas_function_template*ft

SAS transport class function template

voidsas_release_transport(struct scsi_transport_template * t)¶

release SAS transport template instance

Parameters

structscsi_transport_template*t

transport template instance

SATA transport class¶

The SATA transport is handled by libata, which has its own book ofdocumentation in this directory.

Parallel SCSI (SPI) transport class¶

The file drivers/scsi/scsi_transport_spi.c defines transportattributes for traditional (fast/wide/ultra) SCSI busses.

voidspi_schedule_dv_device(struct scsi_device * sdev)¶

schedule domain validation to occur on the device

Parameters

structscsi_device*sdev

The device to validate

Identical to spi_dv_device() above, except that the DV will bescheduled to occur in a workqueue later. All memory allocationsare atomic, so may be called from any context including those holdingSCSI locks.

voidspi_display_xfer_agreement(struct scsi_target * starget)¶

Print the current target transfer agreement

Parameters

structscsi_target*starget

The target for which to display the agreement

Description

Each SPI port is required to maintain a transfer agreement for eachother port on the bus. This function prints a one-line summary ofthe current agreement; more detailed information is available in sysfs.

intspi_populate_tag_msg(unsigned char * msg, struct scsi_cmnd * cmd)¶

place a tag message in a buffer

Parameters

unsignedchar*msg

pointer to the area to place the tag

structscsi_cmnd*cmd

pointer to the scsi command for the tag

Notes

designed to create the correct type of tag message for theparticular request. Returns the size of the tag message.May return 0 if TCQ is disabled for this device.

SCSI RDMA (SRP) transport class¶

The file drivers/scsi/scsi_transport_srp.c defines transportattributes for SCSI over Remote Direct Memory Access.

intsrp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, long dev_loss_tmo)¶

check timeout combination validity

Parameters

intreconnect_delay

Reconnect delay in seconds.

intfast_io_fail_tmo

Fast I/O fail timeout in seconds.

longdev_loss_tmo

Device loss timeout in seconds.

Description

The combination of the timeout parameters must be such that SCSI commandsare finished in a reasonable time. Hence do not allow the fast I/O failtimeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo toexceed that limit if failing I/O fast has been disabled. Furthermore, theseparameters must be such that multipath can detect failed paths timely.Hence do not allow all three parameters to be disabled simultaneously.

voidsrp_start_tl_fail_timers(struct srp_rport * rport)¶

start the transport layer failure timers

Parameters

structsrp_rport*rport

SRP target port.

Description

Start the transport layer fast I/O failure and device loss timers. Do notmodify a timer that was already started.

intsrp_reconnect_rport(struct srp_rport * rport)¶

reconnect to an SRP target port

Parameters

structsrp_rport*rport

SRP target port.

Description

Blocks SCSI command queueing before invoking reconnect() such thatqueuecommand() won’t be invoked concurrently with reconnect() from outsidethe SCSI EH. This is important since a reconnect() implementation mayreallocate resources needed by queuecommand().

Notes

• This function neither waits until outstanding requests have finished nortries to abort these. It is the responsibility of the reconnect()function to finish outstanding commands before reconnecting to the targetport.
• It is the responsibility of the caller to ensure that the resourcesreallocated by the reconnect() function won’t be used while this functionis in progress. One possible strategy is to invoke this function fromthe context of the SCSI EH thread only. Another possible strategy is tolock the rport mutex inside each SCSI LLD callback that can be invoked bythe SCSI EH (the scsi_host_template.eh_*() functions and also thescsi_host_template.queuecommand() function).

enum blk_eh_timer_returnsrp_timed_out(struct scsi_cmnd * scmd)¶

SRP transport intercept of the SCSI timeout EH

Parameters

structscsi_cmnd*scmd

SCSI command.

Description

If a timeout occurs while an rport is in the blocked state, ask the SCSIEH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI corehandle the timeout (BLK_EH_DONE).

Note

This function is called from soft-IRQ context and with the requestqueue lock held.

voidsrp_rport_get(struct srp_rport * rport)¶

increment rport reference count

Parameters

structsrp_rport*rport

SRP target port.

voidsrp_rport_put(struct srp_rport * rport)¶

decrement rport reference count

Parameters

structsrp_rport*rport

SRP target port.

struct srp_rport *srp_rport_add(struct Scsi_Host * shost, struct srp_rport_identifiers * ids)¶

add a SRP remote port to the device hierarchy

Parameters

structScsi_Host*shost

scsi host the remote port is connected to.

structsrp_rport_identifiers*ids

The port id for the remote port.

Description

Publishes a port to the rest of the system.

voidsrp_rport_del(struct srp_rport * rport)¶

remove a SRP remote port

Parameters

structsrp_rport*rport

SRP remote port to remove

Description

Removes the specified SRP remote port.

voidsrp_remove_host(struct Scsi_Host * shost)¶

tear down a Scsi_Host’s SRP data structures

Parameters

structScsi_Host*shost

Scsi Host that is torn down

Description

Removes all SRP remote ports for a given Scsi_Host.Must be called just before scsi_remove_host for SRP HBAs.

voidsrp_stop_rport_timers(struct srp_rport * rport)¶

stop the transport layer recovery timers

Parameters

structsrp_rport*rport

SRP remote port for which to stop the timers.

Description

Must be called aftersrp_remove_host() andscsi_remove_host(). The callermust hold a reference on the rport (rport->dev) and on the SCSI host(rport->dev.parent).

struct scsi_transport_template *srp_attach_transport(struct srp_function_template * ft)¶

instantiate SRP transport template

Parameters

structsrp_function_template*ft

SRP transport class function template

voidsrp_release_transport(struct scsi_transport_template * t)¶

release SRP transport template instance

Parameters

structscsi_transport_template*t

transport template instance

Debug transport¶

The file drivers/scsi/scsi_debug.c simulates a host adapter with avariable number of disks (or disk like devices) attached, sharing acommon amount of RAM. Does a lot of checking to make sure that we arenot getting blocks mixed up, and panics the kernel if anything out ofthe ordinary is seen.

To be more realistic, the simulated devices have the transportattributes of SAS disks.

For documentation seehttp://sg.danny.cz/sg/sdebug26.html

todo¶

Parallel (fast/wide/ultra) SCSI, USB, SATA, SAS, Fibre Channel,FireWire, ATAPI devices, Infiniband, I2O, Parallel ports,netlink…