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>
Implement support for DMA of protection information for devices that
are data integrity capable.
- Add support for mapping an extra scatter-gather list containing
the protection information.
- Allocate protection scsi_data_buffer if host is DIX (integrity DMA)
capable.
- Accessor function for checking whether a device has protection
enabled.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Currently qla4xxx and stex pass in their can_queue values into
scsi_activate_tcq because they wanted the tag map that large.
The problem with this is that it ends up also setting the queue
depth to that large value. All we want to do this in this case
is set the device queue depth and the other device settings.
We do not need to touch the tag map sizing because the drivers
had setup that map according to their can_queue limits when the
shared map was created.
The scsi mid layer in request_fn will then handle the case where we
have more requests than available tags when it checks the host
queue ready function.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
USB sometimes doesn't return an error but instead returns a residue
value indicating part (or all) of the command wasn't completed. So if
the driver _done() error processing indicates the command was fully
processed, subtract off the residue so that this USB error gets
propagated.
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add support for variable-length, extended, and vendor specific
CDBs to scsi-ml. It is now possible for initiators and ULD's
to issue these types of commands. LLDs need not change much.
All they need is to raise the .max_cmd_len to the longest command
they support (see iscsi patch).
- clean-up some code paths that did not expect commands to be
larger than 16, and change cmd_len members' type to short as
char is not enough.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
commit:
commit 542bd1377a
Author: James Bottomley <James.Bottomley@HansenPartnership.com>
Date: Mon Apr 21 10:57:20 2008 -0500
[SCSI] fix SLUB WARN_ON
Fixed another problem in free list handling by moving list allocation
from scsi_host_alloc() to scsi_add_host(). Unfortunately it
introduced a new failure mode in that hosts can pass straight from
alloc to put without going through add, leaving the free list
uninitialised.
Fix by checking shost->cmd_pool on the release path to see if it got
initialised.
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
blk_rq_map_user adjusts bi_size of the last bio. It breaks the rule
that req->data_len (the true data length) is equal to sum(bio). It
broke the scsi command completion code.
commit e97a294ef6 was introduced to fix
the above issue. However, the partial completion code doesn't work
with it. The commit is also a layer violation (scsi mid-layer should
not know about the block layer's padding).
This patch moves the padding adjustment to blk_rq_map_sg (suggested by
James). The padding works like the drain buffer. This patch breaks the
rule that req->data_len is equal to sum(sg), however, the drain buffer
already broke it. So this patch just restores the rule that
req->data_len is equal to sub(bio) without breaking anything new.
Now when a low level driver needs padding, blk_rq_map_user and
blk_rq_map_user_iov guarantee there's enough room for padding.
blk_rq_map_sg can safely extend the last entry of a scatter list.
blk_rq_map_sg must extend the last entry of a scatter list only for a
request that got through bio_copy_user_iov. This patches introduces
new REQ_COPY_USER flag.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This is needed by things like USB storage that want to set up static
commands for later use at start of day.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Since the way we allocate commands with a separate sense buffer is
getting complicated, we should isolate setup and teardown to a single
routine so that if it gets even more complex, there's only one place
in the code that needs to be altered.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Since 2.6.25-rc7, I've been seeing an occasional livelock on one x86_64
machine, copying kernel trees to tmpfs, paging out to swap.
Signature: 6000 pages under writeback but never getting written; most
tasks of interest trying to reclaim, but each get_swap_bio waiting for a
bio in mempool_alloc's io_schedule_timeout(5*HZ); every five seconds an
atomic page allocation failure report from kblockd failing to allocate a
sense_buffer in __scsi_get_command.
__scsi_get_command has a (one item) free_list to protect against this,
but rc1's [SCSI] use dynamically allocated sense buffer
de25deb180 upset that slightly. When it
fails to allocate from the separate sense_slab, instead of giving up, it
must fall back to the command free_list, which is sure to have a
sense_buffer attached.
Either my earlier -rc testing missed this, or there's some recent
contributory factor. One very significant factor is SLUB, which merges
slab caches when it can, and on 64-bit happens to merge both bio cache
and sense_slab cache into kmalloc's 128-byte cache: so that under this
swapping load, bios above are liable to gobble up all the slots needed
for scsi_cmnd sense_buffers below.
That's disturbing behaviour, and I tried a few things to fix it. Adding
a no-op constructor to the sense_slab inhibits SLUB from merging it, and
stops all the allocation failures I was seeing; but it's rather a hack,
and perhaps in different configurations we have other caches on the
swapout path which are ill-merged.
Another alternative is to revert the separate sense_slab, using
cache-line-aligned sense_buffer allocated beyond scsi_cmnd from the one
kmem_cache; but that might waste more memory, and is only a way of
diverting around the known problem.
While I don't like seeing the allocation failures, and hate the idea of
all those bios piled up above a scsi host working one by one, it does
seem to emerge fairly soon with the livelock fix. So lacking better
ideas, stick with that one clear fix for now.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.ziljstra@chello.nl>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Original patch from Tejun Heo <htejun@gmail.com> but should use ->extra_len
and not ->data_len, as we would then overshoot the original request size.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
In preparation for bidi we abstract all IO members of scsi_cmnd,
that will need to duplicate, into a substructure.
- Group all IO members of scsi_cmnd into a scsi_data_buffer
structure.
- Adjust accessors to new members.
- scsi_{alloc,free}_sgtable receive a scsi_data_buffer instead of
scsi_cmnd. And work on it.
- Adjust scsi_init_io() and scsi_release_buffers() for above
change.
- Fix other parts of scsi_lib/scsi.c to members migration. Use
accessors where appropriate.
- fix Documentation about scsi_cmnd in scsi_host.h
- scsi_error.c
* Changed needed members of struct scsi_eh_save.
* Careful considerations in scsi_eh_prep/restore_cmnd.
- sd.c and sr.c
* sd and sr would adjust IO size to align on device's block
size so code needs to change once we move to scsi_data_buff
implementation.
* Convert code to use scsi_for_each_sg
* Use data accessors where appropriate.
- tgt: convert libsrp to use scsi_data_buffer
- isd200: This driver still bangs on scsi_cmnd IO members,
so need changing
[jejb: rebased on top of sg_table patches fixed up conflicts
and used the synergy to eliminate use_sg and sg_count]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Only hosts which actually have ISA DMA requirements need sense buffers
coming out of ZONE_DMA, so only use the __GFP_DMA flag for that case
to avoid allocating this scarce resource if it's not necessary.
[tomo: fixed slab leak in failure case]
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This removes static array sense_buffer in scsi_cmnd and uses
dynamically allocated sense_buffer (with GFP_DMA).
The reason for doing this is that some architectures need cacheline
aligned buffer for DMA:
http://lkml.org/lkml/2007/11/19/2
The problems are that scsi_eh_prep_cmnd puts scsi_cmnd::sense_buffer
to sglist and some LLDs directly DMA to scsi_cmnd::sense_buffer. It's
necessary to DMA to scsi_cmnd::sense_buffer safely. This patch solves
these issues.
__scsi_get_command allocates sense_buffer via kmem_cache_alloc and
attaches it to a scsi_cmnd so everything just work as before.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
- Change title to remove "Mid-Layer" since the doc is about all of the
SCSI layers.
- Use "SCSI" instead of "scsi" in docbook text.
- Use "*/" to end kernel-doc notation blocks.
- A few other minor typo fixes.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Bartlomiej Zolnierkiewicz
Wei Yongjun
Matthew Wilcox
Hannes Reinecke
Christoph Hellwig
Mike Christie
Linus Torvalds
Jens Axboe
James Bottomley
Martin K. Petersen
Boaz Harrosh
Alan D. Brunelle
FUJITA Tomonori
Hugh Dickins
Randy Dunlap