If a scsi host driver specifies .cmd_len in it's scsi_host_template, a driver's
private command pool is needed. scsi_find_host_cmd_pool() will locate it, but
scsi_alloc_host_cmd_pool() isn't saving the pool address in the host template.
This will result in an access error when the host is removed.
Avoid the problem by saving the address of a new allocated command pool where
it is expected.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: 89d9a56795
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
hostt->name might contain space, so use the ->proc_name short name instead
when creating per-driver command slabs.
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Reported-by: poma <pomidorabelisima@gmail.com>
Tested-by: poma <pomidorabelisima@gmail.com>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
Add two new device types, most importantly the zoned block device
one.
Split from an earlier patch by Hannes Reinecke.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch adds support for an alternate I/O path in the scsi midlayer
which uses the blk-mq infrastructure instead of the legacy request code.
Use of blk-mq is fully transparent to drivers, although for now a host
template field is provided to opt out of blk-mq usage in case any unforseen
incompatibilities arise.
In general replacing the legacy request code with blk-mq is a simple and
mostly mechanical transformation. The biggest exception is the new code
that deals with the fact the I/O submissions in blk-mq must happen from
process context, which slightly complicates the I/O completion handler.
The second biggest differences is that blk-mq is build around the concept
of preallocated requests that also include driver specific data, which
in SCSI context means the scsi_cmnd structure. This completely avoids
dynamic memory allocations for the fast path through I/O submission.
Due the preallocated requests the MQ code path exclusively uses the
host-wide shared tag allocator instead of a per-LUN one. This only
affects drivers actually using the block layer provided tag allocator
instead of their own. Unlike the old path blk-mq always provides a tag,
although drivers don't have to use it.
For now the blk-mq path is disable by defauly and must be enabled using
the "use_blk_mq" module parameter. Once the remaining work in the block
layer to make blk-mq more suitable for slow devices is complete I hope
to make it the default and eventually even remove the old code path.
Based on the earlier scsi-mq prototype by Nicholas Bellinger.
Thanks to Bart Van Assche and Robert Elliot for testing, benchmarking and
various sugestions and code contributions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
Seems like these counters are missing any sort of synchronization for
updates, as a over 10 year old comment from me noted. Fix this by
using atomic counters, and while we're at it also make sure they are
in the same cacheline as the _busy counters and not needlessly stored
to in every I/O completion.
With the new model the _busy counters can temporarily go negative,
so all the readers are updated to check for > 0 values. Longer
term every successful I/O completion will reset the counters to zero,
so the temporarily negative values will not cause any harm.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
Avoid taking the host-wide host_lock to check the per-host queue limit.
Instead we do an atomic_inc_return early on to grab our slot in the queue,
and if necessary decrement it after finishing all checks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
The blk-mq code path will set this to a different function, so make the
code simpler by setting it up in a legacy-request specific place.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
Make sure we only have the logic for requeing commands in one place.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
While checking what scsi_adjust_queue_depth() did I thought its switch
statement could be clearer:
- remove redundant assignment (to sdev->queue_depth)
- re-order cases (thus removing the fall-through)
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Tested-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Using dev_printk variants prefixes the logging message with
the originating device, which makes debugging easier.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The SCSI standard defines 64-bit values for LUNs, and large arrays
employing large or hierarchical LUN numbers become more and more
common.
So update the linux SCSI stack to use 64-bit LUN numbers.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
scsi_put_command() is either invoked before blk_start_request() or
after block layer processing has completed. scsi_cmnd.abort_work
is scheduled from inside the SCSI timeout handler. The block layer
guarantees that either the regular completion handler
(softirq_done_fn()) or the timeout handler (rq_timed_out_fn()) is
invoked but not both. This means that scsi_put_command() is never
invoked while abort_work is scheduled. Hence remove the
cancel_delayed_work() call from scsi_put_command().
Similarly, scsi_abort_command() is only invoked from the SCSI
timeout handler. If scsi_abort_command() is invoked for a SCSI
command with the SCSI_EH_ABORT_SCHEDULED flag set this means that
scmd_eh_abort_handler() has already invoked scsi_queue_insert() and
hence that scsi_cmnd.abort_work is no longer pending. Hence also
remove the cancel_delayed_work() call from scsi_abort_command().
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull async SCSI resume support from Dan Williams:
"Allow disks and other devices to resume in parallel.
This provides a tangible speed up for a non-esoteric use case (laptop
resume):
https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach"
* 'async-scsi-resume' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/isci:
scsi: async sd resume
async_schedule() sd resume work to allow disks and other devices to
resume in parallel.
This moves the entirety of scsi_device resume to an async context to
ensure that scsi_device_resume() remains ordered with respect to the
completion of the start/stop command. For the duration of the resume,
new command submissions (that do not originate from the scsi-core) will
be deferred (BLKPREP_DEFER).
It adds a new ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain) as a container
of these operations. Like scsi_sd_probe_domain it is flushed at
sd_remove() time to ensure async ops do not continue past the
end-of-life of the sdev. The implementation explicitly refrains from
reusing scsi_sd_probe_domain directly for this purpose as it is flushed
at the end of dpm_resume(), potentially defeating some of the benefit.
Given sdevs are quiesced it is permissible for these resume operations
to bleed past the async_synchronize_full() calls made by the driver
core.
We defer the resolution of which pm callback to call until
scsi_dev_type_{suspend|resume} time and guarantee that the callback
parameter is never NULL. With this in place the type of resume
operation is encoded in the async function identifier.
There is a concern that async resume could trigger PSU overload. In the
enterprise, storage enclosures enforce staggered spin-up regardless of
what the kernel does making async scanning safe by default. Outside of
that context a user can disable asynchronous scanning via a kernel
command line or CONFIG_SCSI_SCAN_ASYNC. Honor that setting when
deciding whether to do resume asynchronously.
Inspired by Todd's analysis and initial proposal [2]:
https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach
Cc: Len Brown <len.brown@intel.com>
Cc: Phillip Susi <psusi@ubuntu.com>
[alan: bug fix and clean up suggestion]
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
[djbw: kick all resume work to the async queue]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This allows drivers to specify the size of their per-command private
data in the host template and then get extra memory allocated for
each command instead of needing another allocation in ->queuecommand.
With the current SCSI code that already does multiple allocations for
each command this probably doesn't make a big performance impact, but
it allows to clean up the drivers, and prepare them for using the
blk-mq infrastructure where the common allocation will make a difference.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Just have one level of alloc/free functions that take a host instead
of two levels for the allocation and different calling conventions
for the free.
[fengguang.wu@intel.com: docbook problems spotted, now fixed]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
We don't use the passed in scsi command for anything, so just add a adapter-
wide internal status to go along with the internal scb that is used unter
int_mtx to pass back the return value and get rid of all the complexities
and abuse of the scsi_cmnd structure.
This gets rid of the only user of scsi_allocate_command/scsi_free_command,
which can now be removed.
[jejb: checkpatch fixes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
EVPD page 0x83 is used to uniquely identify the device.
So instead of having each and every program issue a separate
SG_IO call to retrieve this information it does make far more
sense to display it in sysfs.
Some older devices (most notably tapes) will only report reliable
information in page 0x80 (Unit Serial Number). So export this
in the sysfs attribute 'vpd_pg80'.
[jejb: checkpatch fix]
[hare: attach after transport configure]
[fengguang.wu@intel.com: spotted problems with the original now fixed]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
We should be returning the number of bytes of the
requested VPD page in scsi_vpd_inquiry.
This makes it easier for the caller to verify the
required space.
[jejb: fix up mm warning spotted by Sergey]
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Many callers won't need this and we can optimize them away. In addition
the handling in the __-prefixed variants was inconsistant to start with.
Based on an earlier patch from Bart Van Assche.
[jejb: fix kerneldoc probelm picked up by Fengguang Wu]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Avoid hitting the host-wide free_list lock unless we need to put a command
back onto the freelist.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
The documentation has gone out-of-sync, so update it to
the current status.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
When a command runs into a timeout we need to send an 'ABORT TASK'
TMF. This is typically done by the 'eh_abort_handler' LLDD callback.
Conceptually, however, this function is a normal SCSI command, so
there is no need to enter the error handler.
This patch implements a new scsi_abort_command() function which
invokes an asynchronous function scsi_eh_abort_handler() to
abort the commands via the usual 'eh_abort_handler'.
If abort succeeds the command is either retried or terminated,
depending on the number of allowed retries. However, 'eh_eflags'
records the abort, so if the retry would fail again the
command is pushed onto the error handler without trying to
abort it (again); it'll be cleared up from SCSI EH.
[hare: smatch detected stray switch fixed]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Field is now unused, so this is dead code.
[jejb: remove resetting and last_reset from Scsi_Host]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
If a device has the skip_vpd_pages flag set we should simply fail the
scsi_get_vpd_page() call.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Stuart Foster <smf.linux@ntlworld.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
SATA drives located behind a SAS controller would incorrectly receive
WRITE SAME commands. Tweak the heuristics so that:
- If REPORT SUPPORTED OPERATION CODES is provided we will use that to
choose between WRITE SAME(16), WRITE SAME(10) and disabled. This also
fixes an issue with the old code which would issue WRITE SAME(10)
despite the command not being whitelisted in REPORT SUPPORTED
OPERATION CODES.
- If REPORT SUPPORTED OPERATION CODES is not provided we will fall back
to WRITE SAME(10) unless the device has an ATA Information VPD page.
The assumption is that a SATL which is smart enough to implement
WRITE SAME would also provide REPORT SUPPORTED OPERATION CODES.
To facilitate the new heuristics scsi_report_opcode() has been modified
to so we can distinguish between "operation not supported" and "RSOC not
supported".
Reported-by: H. Peter Anvin <hpa@zytor.com>
Tested-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
The REPORT SUPPORTED OPERATION CODES command can be used to query
whether a given opcode is supported by a device. Add a helper function
that allows us to look up commands.
We only issue RSOC if the device reports compliance with SPC-3 or
later. But to err on the side of caution we disable the command for ATA,
FireWire and USB.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
In response to an async related regression James noted:
"My theory is that this is an init problem: The assumption in a lot of
our code is that async_synchronize_full() waits for everything ... even
the domain specific async schedules, which isn't true."
...so make this assumption true.
Each domain, including the default one, registers itself on a global domain
list when work is scheduled. Once all entries complete it exits that
list. Waiting for the list to be empty syncs all in-flight work across
all domains.
Domains can opt-out of global syncing if they are declared as exclusive
ASYNC_DOMAIN_EXCLUSIVE(). All stack-based domains have been declared
exclusive since the domain may go out of scope as soon as the last work
item completes.
Statically declared domains are mostly ok, but async_unregister_domain()
is there to close any theoretical races with pending
async_synchronize_full waiters at module removal time.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Reported-by: Meelis Roos <mroos@linux.ee>
Reported-by: Eldad Zack <eldadzack@gmail.com>
Tested-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This is in preparation for teaching async_synchronize_full() to sync all
pending async work, and not just on the async_running domain. This
conversion is functionally equivalent, just embedding the existing list
in a new async_domain type.
The .registered attribute is used in a later patch to distinguish
between domains that want to be flushed by async_synchronize_full()
versus those that only expect async_synchronize_{full|cookie}_domain to
be used for flushing.
[jejb: add async.h to scsi_priv.h for struct async_domain]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Tested-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
With CONFIG_BLK_DEV_SD = n and CONFIG_PM = n, you get this compile failure:
(.text+0x4f6c77): undefined reference to `scsi_sd_probe_domain'
This was introduced by
commit a7a20d1039
Author: Dan Williams <dan.j.williams@intel.com>
Date: Thu Mar 22 17:05:11 2012 -0700
[SCSI] sd: limit the scope of the async probe domain
And happens because scsi_sd_probe_domain is conditionally defined but
unconditionally used. Fix this by making the symbol unconditionally defined.
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Tested-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
We have experienced several devices which fail in a fashion we do not
currently handle gracefully in SCSI. After a failure these devices will
respond to the SCSI primary command set (INQUIRY, TEST UNIT READY, etc.)
but any command accessing the storage medium will time out.
The following patch adds an callback that can be used by upper level
drivers to inspect the results of an error handling command. This in
turn has been used to implement additional checking in the SCSI disk
driver.
If a medium access command fails twice but TEST UNIT READY succeeds both
times in the subsequent error handling we will offline the device. The
maximum number of failed commands required to take a device offline can
be tweaked in sysfs.
Also add a new error flag to scsi_debug which allows this scenario to be
easily reproduced.
[jejb: fix up integer parsing to use kstrtouint]
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.
The patch below presents a simple SCSI host lock push-down as an
equivalent transformation. No locking or other behavior should change
with this patch. All existing bugs and locking orders are preserved.
Additionally, add one parameter to queuecommand,
struct Scsi_Host *
and remove one parameter from queuecommand,
void (*done)(struct scsi_cmnd *)
Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.
Minimal code disturbance was attempted with this change. Most drivers
needed only two one-line modifications for their host lock push-down.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix two bugs in the VPD page wrapper:
- Don't return failure if the user asked for page 0
- The end of buffer check failed to account for the page header size
and consequently didn't work
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Add missing kernel-doc notation for new function parameters:
Warning(drivers/scsi/scsi.c:1031): No description found for parameter 'buf'
Warning(drivers/scsi/scsi.c:1031): No description found for parameter 'buf_len'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The best way to fix this is to eliminate the intenal kmalloc() and
make the caller allocate the required amount of storage.
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Current FC HBA queue_depth ramp up code depends on last queue
full time. The sdev already has last_queue_full_time field to
track last queue full time but stored value is truncated by
last four bits.
So this patch updates last_queue_full_time without truncating
last 4 bits to store full value and then updates its only
current usages in scsi_track_queue_full to ignore last four bits
to keep current usages same while also use this field
in added ramp up code.
Adds scsi_handle_queue_ramp_up to ramp up queue_depth on
successful completion of IO. The scsi_handle_queue_ramp_up will
do ramp up on all luns of a target, just same as ramp down done
on all luns on a target.
The ramp up is skipped in case the change_queue_depth is not
supported by LLD or already reached to added max_queue_depth.
Updates added max_queue_depth on every new update to default
queue_depth value.
The ramp up is also skipped if lapsed time since either last
queue ramp up or down is less than LLD specified
queue_ramp_up_period.
Adds queue_ramp_up_period to sysfs but only if change_queue_depth
is supported since ramp up and queue_ramp_up_period is needed only
in case change_queue_depth is supported first.
Initializes queue_ramp_up_period to 120HZ jiffies as initial
default value, it is same as used in existing lpfc and qla2xxx.
-v2
Combined all ramp code into this single patch.
-v3
Moves max_queue_depth initialization after slave_configure is
called from after slave_alloc calling done. Also adjusted
max_queue_depth check to skip ramp up if current queue_depth
is >= max_queue_depth.
-v4
Changes sdev->queue_ramp_up_period unit to ms when using sysfs i/f
to store or show its value.
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Tested-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
We would leak a scsi_data_buffer if the free_list command was of the
protected variety.
Reported-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Universally, SCSI functions assume the lengths fed in are those of the buffer
to DMA data to, not the lengths of the data minus the header.
scsi_vpd_inquiry() assumed the latter and got it wrong, so fix up all the
functions to use the correct assumption (and fix a bug where INQUIRY in SCSI-2
dcannot go over 255).
[jejb: Matthew posted an identical version of this at the same time I did]
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Based on prior work by Martin Petersen and James Bottomley, this patch
adds a generic helper for retrieving VPD pages from SCSI devices.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
__scsi_device_lookup_by_target() will always return
the first sdev with a matching LUN, regardless of
the state. However, when this sdev is in SDEV_DEL
scsi_device_lookup_by_target() will ignore this
device and so any valid device on the list after
the deleted device will never be found.
So we have to modify __scsi_device_lookup_by_target()
to skip any device in SDEV_DEL.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
SCSI-ml manages the queueing limits for the device and host, but
does not do so at the target level. However something something similar
can come in userful when a driver is transitioning a transport object to
the the blocked state, becuase at that time we do not want to queue
io and we do not want the queuecommand to be called again.
The patch adds code similar to the exisiting SCSI_ML_*BUSY handlers.
You can now return SCSI_MLQUEUE_TARGET_BUSY when we hit
a transport level queueing issue like the hw cannot allocate some
resource at the iscsi session/connection level, or the target has temporarily
closed or shrunk the queueing window, or if we are transitioning
to the blocked state.
bnx2i, when they rework their firmware according to netdev
developers requests, will also need to be able to limit queueing at this
level. bnx2i will hook into libiscsi, but will allocate a scsi host per
netdevice/hba, so unlike pure software iscsi/iser which is allocating
a host per session, it cannot set the scsi_host->can_queue and return
SCSI_MLQUEUE_HOST_BUSY to reflect queueing limits on the transport.
The iscsi class/driver can also set a scsi_target->can_queue value which
reflects the max commands the driver/class can support. For iscsi this
reflects the number of commands we can support for each session due to
session/connection hw limits, driver limits, and to also reflect the
session/targets's queueing window.
Changes:
v1 - initial patch.
v2 - Fix scsi_run_queue handling of multiple blocked targets.
Previously we would break from the main loop if a device was added back on
the starved list. We now run over the list and check if any target is
blocked.
v3 - Rediff for scsi-misc.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (37 commits)
[SCSI] zfcp: fix double dbf id usage
[SCSI] zfcp: wait on SCSI work to be finished before proceeding with init dev
[SCSI] zfcp: fix erp list usage without using locks
[SCSI] zfcp: prevent fc_remote_port_delete calls for unregistered rport
[SCSI] zfcp: fix deadlock caused by shared work queue tasks
[SCSI] zfcp: put threshold data in hba trace
[SCSI] zfcp: Simplify zfcp data structures
[SCSI] zfcp: Simplify get_adapter_by_busid
[SCSI] zfcp: remove all typedefs and replace them with standards
[SCSI] zfcp: attach and release SAN nameserver port on demand
[SCSI] zfcp: remove unused references, declarations and flags
[SCSI] zfcp: Update message with input from review
[SCSI] zfcp: add queue_full sysfs attribute
[SCSI] scsi_dh: suppress comparison warning
[SCSI] scsi_dh: add Dell product information into rdac device handler
[SCSI] qla2xxx: remove the unused SCSI_QLOGIC_FC_FIRMWARE option
[SCSI] qla2xxx: fix printk format warnings
[SCSI] qla2xxx: Update version number to 8.02.01-k8.
[SCSI] qla2xxx: Ignore payload reserved-bits during RSCN processing.
[SCSI] qla2xxx: Additional residual-count corrections during UNDERRUN handling.
...
Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.
Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The created and blocked states are very shortly going to correspond to
mixed sdev_state states.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
