patch
commit b60af5b0ad
Author: Alan Stern <stern@rowland.harvard.edu>
Date: Mon Nov 3 15:56:47 2008 -0500
[SCSI] simplify scsi_io_completion()
broke DIX error handling. Also, we are now using EILSEQ to indicate
integrity errors to the upper layers (as opposed to regular EIO
failures). This allows filesystems to inspect buffers and decide
whether to retry the I/O. Update scsi_io_completion() accordingly.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
A bug was introduced by
commit b60af5b0ad
Author: Alan Stern <stern@rowland.harvard.edu>
Date: Mon Nov 3 15:56:47 2008 -0500
[SCSI] simplify scsi_io_completion()
because the simplification uses scsi_queue_insert(). The problem with
this function is that it expects to be called from the completion path
while the command is still outstanding, so it decrements the device
and host busy counts to do the requeue. The problem is that
scsi_io_completion() is a path executed well after these counts have
*already* been decremented, leading to a double decrement if the
command goes down any error path leading to ACTION_DELAYED_RETRY.
The fix is to allow a private function __scsi_queue_insert() with a
flag to say whether the busy counters should be decremented. This is
made static to scsi_lib.c to discourage other use.
Reported-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch (as1191) adds a missing "default" case in
scsi_io_completion(), thereby fixing an "uninitialized variable"
error. It also adds a missing newline to a log entry.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
scsi_execute() and scsi_execute_req() discard the residual length
information. Some callers need it. This adds residual argument
(optional) to scsi_execute and scsi_execute_req.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch (as1142b) consolidates a lot of repetitious code in
scsi_io_completion(). It also fixes a few comments. Most
importantly, however, it clearly distinguishes among the three sorts
of retries that can be done when a command fails to complete:
Unprepare the request and resubmit it, so that a new
command will be created for it.
Requeue the request directly so that it will be retried
immediately using the same command.
Requeue the request so that it will be retried following
a short delay.
Complete the remainder of the request with an I/O error.
[jejb: Updates
1. For several error conditions, we would now print the sense twice
in slightly different ways, so unify the location of sense
printing.
2. I added more descriptions to actual failure conditions for
better debugging
3. according to spec, ABORTED_COMMAND is supposed to be retried
(except on DIF failure). Our old behaviour of erroring it looks
to be a bug.
4. I'd prefer not to default initialise the action variable because
that ensures that every leg of the error handler has an
associated action and the compiler will warn if someone later
accidentally misses one or removes one.
]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
It's called under that lock everywhere else and it does alter the
request state, so it should be.
This one occurance in scsi_requeue_command() could open a window where
req->special is set to NULL while the requests is going through either
timeout or completion processing leading to NULL pointer derefs of the
sort complained of in bugzillas 12020 and 12195.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Close possible infinite loop with interrupts off when devices are
added back to the starved list.
Fixes: http://bugzilla.kernel.org/show_bug.cgi?id=11898
Reported-by: <alex.shi@intel.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch implements q->lld_busy_fn() for scsi mid layer to export
its busy state for request stacking drivers.
For efficiency, no lock is taken to check the busy state of
shost/starget/sdev, since the returned value is not guaranteed and
may be changed after request stacking drivers call the function,
regardless of taking lock or not.
When scsi can't dispatch I/Os anymore and needs to kill I/Os
(e.g. !sdev), scsi needs to return 'not busy'.
Otherwise, request stacking drivers may hold requests forever.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch refactors the busy checking codes of scsi_device,
Scsi_Host and scsi_target. There should be no functional change.
This is a preparation for another patch which exports scsi's busy
state to the block layer for request stacking drivers.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
On Tue, 12 Aug 2008 15:08:14 +0200
Giuliano Pochini <pochini@shiny.it> wrote:
> Fujitsu magneto-optical drive, Adaptec 29160 and
> Linux Jay 2.6.26 #7 SMP Sun Aug 10 18:34:22 CEST 2008 ppc 7455, altivec supported PowerMac3,6 GNU/Linux
>
> When I insert a disk and I mount it, scsi_test_unit_ready() is called and
> the do-while loop gets sshdr->sense_key == UNIT_ATTENTION in the first
> cycle and 0 in the second one. So the if below misses the UNIT_ATTENTION
> and sdev->changed = 1 is not executed. At this point bad things can
> happen... I'm not sure how to fix this. Any clue ?
The problem is essentially caused by us eating UNIT_ATTENTION
conditions in scsi_test_unit_ready(). Fix by updating the ->changed
flag when this happens if the media is removable.
[pochini@shiny.it: updates to tidy up patch]
Signed-off-by: Giuliano Pochini <pochini@shiny.it>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This checks the errors the scsi-ml determined were retryable
and returns if we should fast fail it based on the request
fail fast flags.
Without the patch, drivers like lpfc, qla2xxx and fcoe would return
DID_ERROR for what it determines is a temporary communication problem.
There is no loss of connectivity at that time and the driver thinks
that it would be fast to retry at the driver level. SCSI-ml will however
sees fast fail on the request and DID_ERROR and will fast fail the io.
This will then cause dm-multipath to fail the path and possibley switch
target controllers when we should be retrying at the scsi layer.
We also were fast failing device errors to dm multiapth when
unless the scsi_dh modules think otherwis we want to retry at
the scsi layer because multipath can only retry the IO like scsi
should have done. multipath is a little dumber though because it
does not what the error was for and assumes that it should fail
the paths.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
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>
Brian King <brking@linux.vnet.ibm.com> reported that fibre channel
devices can oops during scanning if their ports block (because the
device goes from CREATED -> BLOCK -> RUNNING rather than CREATED ->
BLOCK -> CREATED).
Fix this by adding a new state: CREATED_BLOCK which can only transition
back to CREATED and disallow the CREATED -> BLOCK transition. Now both
the created and blocked states that the mid-layer recognises can include
CREATED_BLOCK.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Sometimes, particularly for USB devices with the last sector bug,
requests get completed in chunks. There's a bug in this in that if
one of the chunks gets an error, we complete that chunk with an error
but never move on to the remaining ones, leading to the request
hanging (because it's not fully completed).
Fix this by completing all remaining chunks if an error is encountered.
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
[jejb: fixed up a ton of missed conversions.
All of you are on notice this has happened, driver trees will now
need to be rebased]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: SCSI List <linux-scsi@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
I goofed and did not see the macro for checking if a request is tagged.
This patch has us use blk_rq_tagged instead of digging into the req->tag.
Patch was made over scsi-misc.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
If initiator or target reject the I/O due to DIF errors there is no
point in retrying.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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>
When drivers use a shared tag map we can end up with more requests
than tags, because the tag map is shost->can_queue tags and there
can be sdevs * sdev->queue_depth requests. In scsi_request_fn
if tag allocation fails we just drop down to just dequeueing the
tag without a tag. The problem is that drivers using the shared tag
map rely on a valid tag always being set, because it will use the
tag number to lookup commands later.
This patch has us check if we got a valid tag when the host lock
is held right before we check if the host queue is ready. We do the
check here because to allocate the tag we need the q lock, but
if the tag is bad we want to add the device/q onto the starved list
which requires the host lock.
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: (102 commits)
[SCSI] scsi_dh: fix kconfig related build errors
[SCSI] sym53c8xx: Fix bogus sym_que_entry re-implementation of container_of
[SCSI] scsi_cmnd.h: remove double inclusion of linux/blkdev.h
[SCSI] make struct scsi_{host,target}_type static
[SCSI] fix locking in host use of blk_plug_device()
[SCSI] zfcp: Cleanup external header file
[SCSI] zfcp: Cleanup code in zfcp_erp.c
[SCSI] zfcp: zfcp_fsf cleanup.
[SCSI] zfcp: consolidate sysfs things into one file.
[SCSI] zfcp: Cleanup of code in zfcp_aux.c
[SCSI] zfcp: Cleanup of code in zfcp_scsi.c
[SCSI] zfcp: Move status accessors from zfcp to SCSI include file.
[SCSI] zfcp: Small QDIO cleanups
[SCSI] zfcp: Adapter reopen for large number of unsolicited status
[SCSI] zfcp: Fix error checking for ELS ADISC requests
[SCSI] zfcp: wait until adapter is finished with ERP during auto-port
[SCSI] ibmvfc: IBM Power Virtual Fibre Channel Adapter Client Driver
[SCSI] sg: Add target reset support
[SCSI] lib: Add support for the T10 (SCSI) Data Integrity Field CRC
[SCSI] sd: Move scsi_disk() accessor function to sd.h
...
scsi_lib.c:scsi_host_queue_ready() plugs the device with incorrect
locking. It should actually have the queue lock held, but it's
holding the host lock. Fix this by eliminating the call. The host
ready has no need to plug the queue because if it returns 0 in
scsi_request_function control transfers to not_ready which acquires
the queue lock and plugs the device if its at zero depth.
Reported-by: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The data integrity changes need to dynamically allocate
scsi_data_buffers too. Rename scsi_bidi_sdb_cache for clarity.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch (as1108) fixes a problem that can occur with certain USB
mass-storage devices: They return invalid data together with a residue
indicating that the data should be ignored. Rather than leave the
invalid data in a transfer buffer, where it can get misinterpreted,
the patch clears the invalid portion of the buffer.
This solves a problem (wrong write-protect setting detected) reported
by Maciej Rutecki and Peter Teoh.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Peter Teoh <htmldeveloper@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Some of the storage devices (that can be accessed through multiple paths),
do need some special handling for
1. Activating the passive path of the storage access.
2. Decode and handle the special sense codes returned by the devices.
3. Handle the I/Os being sent to the passive path, especially
during the device probe time.
when accessed through multiple paths.
As of today this special device handling is done at the dm-multipath
layer using dm-handlers. That works well for (1); for (2) to be handled
at dm layer, scsi sense information need to be exported from SCSI to dm-layer,
which is not very attractive; (3) cannot be done at all at the dm layer.
Device handler has been moved to SCSI mainly to handle (2) and (3) properly.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
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:
[SCSI] aic94xx: fix section mismatch
[SCSI] u14-34f: Fix 32bit only problem
[SCSI] dpt_i2o: sysfs code
[SCSI] dpt_i2o: 64 bit support
[SCSI] dpt_i2o: move from virt_to_bus/bus_to_virt to dma_alloc_coherent
[SCSI] dpt_i2o: use standard __init / __exit code
[SCSI] megaraid_sas: fix suspend/resume sections
[SCSI] aacraid: Add Power Management support
[SCSI] aacraid: Fix jbod operations scan issues
[SCSI] aacraid: Fix warning about macro side-effects
[SCSI] add support for variable length extended commands
[SCSI] Let scsi_cmnd->cmnd use request->cmd buffer
[SCSI] bsg: add large command support
[SCSI] aacraid: Fix down_interruptible() to check the return value correctly
[SCSI] megaraid_sas; Update the Version and Changelog
[SCSI] ibmvscsi: Handle non SCSI error status
[SCSI] bug fix for free list handling
[SCSI] ipr: Rename ipr's state scsi host attribute to prevent collisions
[SCSI] megaraid_mbox: fix Dell CERC firmware problem
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>
- struct scsi_cmnd had a 16 bytes command buffer of its own.
This is an unnecessary duplication and copy of request's
cmd. It is probably left overs from the time that scsi_cmnd
could function without a request attached. So clean that up.
- Once above is done, few places, apart from scsi-ml, needed
adjustments due to changing the data type of scsi_cmnd->cmnd.
- Lots of drivers still use MAX_COMMAND_SIZE. So I have left
that #define but equate it to BLK_MAX_CDB. The way I see it
and is reflected in the patch below is.
MAX_COMMAND_SIZE - means: The longest fixed-length (*) SCSI CDB
as per the SCSI standard and is not related
to the implementation.
BLK_MAX_CDB. - The allocated space at the request level
- I have audit all ISA drivers and made sure none use ->cmnd in a DMA
Operation. Same audit was done by Andi Kleen.
(*)fixed-length here means commands that their size can be determined
by their opcode and the CDB does not carry a length specifier, (unlike
the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
true and the SCSI standard also defines extended commands and
vendor specific commands that can be bigger than 16 bytes. The kernel
will support these using the same infrastructure used for VARLEN CDB's.
So in effect MAX_COMMAND_SIZE means the maximum size command
scsi-ml supports without specifying a cmd_len by ULD's
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
We can save some atomic ops in the IO path, if we clearly define
the rules of how to modify the queue flags.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently, if the barrier command fails, the error return isn't seen
by the block layer and it proceeds on regardless. The problem is that
SCSI always returns no error for REQ_TYPE_BLOCK_PC ... it expects the
submitter to pick the errors out of req->errors, which the block
barrier functions don't do.
Since it appears that the way SG_IO and scsi_execute_request() work
they discard the block error return and always use req->errors, the
best fix for this is to have the SCSI layer return an error to block
if one actually occurred (this also allows us to filter out spurious
errors, like deferred sense).
This patch is a bug fix that will need backporting to stable, but it's
also quite a big change and in need of testing, so we'll incubate in
the main kernel tree and backport at the -rc2 or so stage if no
problems turn up.
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch makes the needlessly global scsi_end_bidi_request() static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Commit:
a341cd0f (SCSI: add asynchronous event notification API)
breaks:
285e9670 (sr,sd: send media state change modification events)
by introducing an event filter, which is removed here, to make
events, we are depending on, happen again.
Fix this by removing the event filter. It's pretty much broken at the
moment, since a user can't set it (the attribute being read only). A
proper fix will be to make the event discriminator distinguish between
AN and Polled media change events.
Cc: David Zeuthen <david@fubar.dk>
Cc: kristen accardi <kaccardi@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
With padding and draining moved into it, block layer now may extend
requests as directed by queue parameters, so now a request has two
sizes - the original request size and the extended size which matches
the size of area pointed to by bios and later by sgs. The latter size
is what lower layers are primarily interested in when allocating,
filling up DMA tables and setting up the controller.
Both padding and draining extend the data area to accomodate
controller characteristics. As any controller which speaks SCSI can
handle underflows, feeding larger data area is safe.
So, this patch makes the primary data length field, request->data_len,
indicate the size of full data area and add a separate length field,
request->raw_data_len, for the unmodified request size. The latter is
used to report to higher layer (userland) and where the original
request size should be fed to the controller or device.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
When sending a SCSI command to a tape drive via the SCSI Generic (sg)
driver, if the command has a data transfer length more than
scatter_elem_sz (32 KB default) and not a multiple of 512, then I either
hit BUG_ON(!valid_dma_direction(direction)) in dma_unmap_sg() or else
the command never completes (depending on the LLDD).
When constructing scatterlists, the sg driver rounds up the scatterlist
element sizes to be a multiple of 512. This can result in
sum(scatterlist lengths) > bufflen. In this case, scsi_req_map_sg()
incorrectly sets bio->bi_size to sum(scatterlist lengths) rather than to
bufflen. When the command completes, req_bio_endio() detects that
bio->bi_size != 0, and so it doesn't call bio_endio(). This causes the
command to be resubmitted, resulting in BUG_ON or the command never
completing.
This patch makes scsi_req_map_sg() set bio->bi_size to bufflen rather
than to sum(scatterlist lengths), which fixes the problem.
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This is a one-line patch to add the following to __scsi_alloc_queue():
dma_set_seg_boundary(dev, shost->dma_boundary);
This is the simplest approach but the result looks odd,
__scsi_alloc_queue() does:
blk_queue_segment_boundary(q, shost->dma_boundary);
dma_set_seg_boundary(dev, shost->dma_boundary);
blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
I think that it would be better to set up segment boundary in the same
way as we did for the maximum segment size. That is, removing
shost->dma_boundary and LLDs call pci_set_dma_seg_boundary (or its
friends).
Then __scsi_alloc_queue() can set up both limits in the same way:
blk_queue_segment_boundary(q, dma_get_seg_boundary(dev));
blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
killing dma_boundary in scsi_host_template needs a large patch for
libata (dma_boundary is used by only libata and sym53c8xx). I'll send
a patch to do that if it is acceptable. James and Jeff?
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Greg KH <greg@kroah.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
request_queue and device struct must have the same value of a segment
size limit. This patch adds blk_queue_segment_boundary in
__scsi_alloc_queue so LLDs don't need to call both
blk_queue_segment_boundary and set_dma_max_seg_size. A LLD can change
the default value (64KB) can call device_dma_parameters accessors like
pci_set_dma_max_seg_size when allocating scsi_host.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
scsi_init_queue is expected to clean up allocated things when it
fails.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Needs to call kmem_cache_destroy for scsi_bidi_sdb_cache in
scsi_exit_queue.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
With the sg table code, every SCSI driver is now either chain capable
or broken (or has sg_tablesize set so chaining is never activated), so
there's no need to have a check in the host template.
Also tidy up the code by moving the scatterlist size defines into the
SCSI includes and permit the last entry of the scatterlist pools not
to be a power of two.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
At the block level bidi request uses req->next_rq pointer for a second
bidi_read request.
At Scsi-midlayer a second scsi_data_buffer structure is used for the
bidi_read part. This bidi scsi_data_buffer is put on
request->next_rq->special. Struct scsi_cmnd is not changed.
- Define scsi_bidi_cmnd() to return true if it is a bidi request and a
second sgtable was allocated.
- Define scsi_in()/scsi_out() to return the in or out scsi_data_buffer
from this command This API is to isolate users from the mechanics of
bidi.
- Define scsi_end_bidi_request() to do what scsi_end_request() does but
for a bidi request. This is necessary because bidi commands are a bit
tricky here. (See comments in body)
- scsi_release_buffers() will also release the bidi_read scsi_data_buffer
- scsi_io_completion() on bidi commands will now call
scsi_end_bidi_request() and return.
- The previous work done in scsi_init_io() is now done in a new
scsi_init_sgtable() (which is 99% identical to old scsi_init_io())
The new scsi_init_io() will call the above twice if needed also for
the bidi_read command. Only at this point is a command bidi.
- In scsi_error.c at scsi_eh_prep/restore_cmnd() make sure bidi-lld is not
confused by a get-sense command that looks like bidi. This is done
by puting NULL at request->next_rq, and restoring.
[jejb: update to sg_table and resolve conflicts
also update to blk-end-request and resolve conflicts]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.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>
If we export scsi_init_io()/scsi_release_buffers() instead of
scsi_{alloc,free}_sgtable() from scsi_lib than tgt code is much more
insulated from scsi_lib changes. As a bonus it will also gain bidi
capability when it comes.
[jejb: rebase on to sg_table and fix up rejections]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
SCSI sg table allocation has a maximum size (of SCSI_MAX_SG_SEGMENTS,
currently 128) and this will cause a BUG_ON() in SCSI if something
tries an allocation over it. This patch adds a size limit to the
chaining allocator to allow the specification of the maximum
allocation size for chaining, so we always chain in units of the
maximum SCSI allocation size.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch converts scsi mid-layer to use blk_end_request interfaces.
Related 'uptodate' arguments are converted to 'error'.
As a result, the interface of internal function, scsi_end_request(),
is changed.
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Also change scsi_alloc_sgtable() to just return 0/failure, since it
maps to the command passed in. ->request_buffer is now no longer needed,
once drivers are adapted to use scsi_sglist() it can be killed.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This replaces sizeof sense_buffer with SCSI_SENSE_BUFFERSIZE in
several LLDs. It's a preparation for the future changes to remove
sense_buffer array in scsi_cmnd structure.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch relaxes the default SCSI DMA alignment from 512 bytes to 4
bytes. I remember from previous discussions that usb and firewire have
sector size alignment requirements, so I upped their alignments in the
respective slave allocs.
The reason for doing this is so that we don't get such a huge amount of
copy overhead in bio_copy_user() for udev. (basically all inquiries it
issues can now be directly mapped).
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The current scsi_test_unit_ready() is updated to return sense code
information (in struct scsi_sense_hdr). The sd and sr drivers are
changed to interpret the sense code return asc 0x3a as no media and
adjust the device status accordingly.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
If blk_rq_map_sg wrote more than was allocated in the scatterlist,
BUG_ON() is probably the right thing to do.
[jejb: rejections fixed up]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Some SCSI tape medium changers that need the BLIST_SINGLELUN flag have
the medium changer at one LUN and the tape drive at a different LUN.
The inquiry string of the tape drive may be different from that of the
medium changer. In order for single_lun to be effective, every
scsi_device under a given scsi_target must have it set. This means that
there needs to be a blacklist entry for BOTH the medium changer AND the
tape drive, which is impractical because some medium changers may be
paired with a variety of different tape drive models. It makes more
sense to put the single_lun flag in scsi_target instead of scsi_device,
which causes every device at a given target ID to inherit the single_lun
flag from one LUN. This makes it possible to blacklist just the medium
changer and not the tape drive.
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add Documentation/DocBook/scsi_midlayer.tmpl, add to Makefile, and update
lots of kerneldoc comments in drivers/scsi/*.
Updated with comments from Stefan Richter, Stephen M. Cameron,
James Bottomley and Randy Dunlap.
Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This reverts commit ac40532ef0, which gets
us back the original cleanup of 6f5391c283.
It turns out that the bug that was triggered by that commit was
apparently not actually triggered by that commit at all, and just the
testing conditions had changed enough to make it appear to be due to it.
The real problem seems to have been found by Peter Osterlund:
"pktcdvd sets it [block device size] when opening the /dev/pktcdvd
device, but when the drive is later opened as /dev/scd0, there is
nothing that sets it back. (Btw, 40944 is possible if the disk is a
CDRW that was formatted with "cdrwtool -m 10236".)
The problem is that pktcdvd opens the cd device in non-blocking mode
when pktsetup is run, and doesn't close it again until pktsetup -d is
run. The effect is that if you meanwhile open the cd device,
blkdev.c:do_open() doesn't call bd_set_size() because
bdev->bd_openers is non-zero."
In particular, to repeat the bug (regardless of whether commit
6f5391c283 is applied or not):
" 1. Start with an empty drive.
2. pktsetup 0 /dev/scd0
3. Insert a CD containing an isofs filesystem.
4. mount /dev/pktcdvd/0 /mnt/tmp
5. umount /mnt/tmp
6. Press the eject button.
7. Insert a DVD containing a non-writable filesystem.
8. mount /dev/scd0 /mnt/tmp
9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null
10. If the DVD contains data beyond the physical size of a CD, you
get I/O errors in the terminal, and dmesg reports lots of
"attempt to access beyond end of device" errors."
which in turn is because the nested open after the media change won't
cause the size to be set properly (because the original open still holds
the block device, and we only do the bd_set_size() when we don't have
other people holding the device open).
The proper fix for that is probably to just do something like
bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9;
in fs/block_dev.c:do_open() even for the cases where we're not the
original opener (but *not* call bd_set_size(), since that will also
change the block size of the device).
Cc: Peter Osterlund <petero2@telia.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 6f5391c283 ("[SCSI]
Get rid of scsi_cmnd->done") that was supposed to be a cleanup commit,
but apparently it causes regressions:
Bug 9370 - v2.6.24-rc2-409-g9418d5d: attempt to access beyond end of device
http://bugzilla.kernel.org/show_bug.cgi?id=9370
this patch should be reintroduced in a more split-up form to make
testing of it easier.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A recent bug report:
http://bugzilla.kernel.org/show_bug.cgi?id=9674
Was caused because the ULDs now set their own prep functions, but
don't necessarily reset the prep function back to the SCSI default
when they are removed. This leads to panics if commands are sent to
the device after the module is removed because the prep_fn is still
pointing to the old module code. The fix for this is to implement a
bus remove method that resets the prep_fn pointer correctly before
calling the ULD specific driver remove method.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
sg_mark_end() overwrites the page_link information, but all users want
__sg_mark_end() behaviour where we just set the end bit. That is the most
natural way to use the sg list, since you'll fill it in and then mark the
end point.
So change sg_mark_end() to only set the termination bit. Add a sg_magic
debug check as well, and clear a chain pointer if it is set.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
A bit too eager - we definitely need to clear the sg table
initially, so that we don't accidentally have ->page & 0x01
true and think that is a chain pointer.
This reverts commit f5c0dde4c6.
This reverts sg segment size ifdefs that the current code has in order
to provide a way to reduce sgpool memory consumption.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This option is true if a low-level driver can support sg
chaining. This will be removed eventually when all the drivers are
converted to support sg chaining. q->max_phys_segments is set to
SCSI_MAX_SG_SEGMENTS if false.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This is what enables large commands. If we need to allocate an
sgtable that doesn't fit in a single page, allocate several
SCSI_MAX_SG_SEGMENTS sized tables and chain them together.
SCSI defaults to large chained sg tables, if the arch supports it.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Just pass in the command, no point in passing in the scatterlist
and scatterlist pool index seperately.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This converts the SCSI mid layer to using the sg helpers for looking up
sg elements, instead of doing it manually.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The ULD ->done callback moves into the scsi_driver. By moving the call
to scsi_io_completion() from scsi_blk_pc_done() to scsi_finish_command(),
we can eliminate the latter entirely. By returning 'good_bytes' from
the ->done callback (rather than invoking scsi_io_completion()), we can
stop exporting scsi_io_completion().
Also move the prototypes from sd.h to sd.c as they're all internal anyway.
Rename sd_rw_intr to sd_done and rw_intr to sr_done.
Inspired-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Because scsi_print_sense_hdr prefixes with KERN_INFO, the output from
scsi_io_completion looks like:
sd 0:0:0:0: [sdb] Device not ready: <6>: Sense Key : 0x2 [current]
: ASC=0x4 ASCQ=0x3
By using scsi_show_sense_hdr, we can get the much more appealing output:
sd 0:0:0:0: [sdb] Device not ready: Sense Key : 0x2 [current]
sd 0:0:0:0: [sdb] Device not ready: ASC=0x4 ASCQ=0x3
Acked-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
One of the intents of the block prep function was to allow ULDs to use
it for preprocessing. The original SCSI model was to have a single prep
function and add a pointer indirect filter to build the necessary
commands. This patch reverses that, does away with the init_command
field of the scsi_driver structure and makes ULDs attach directly to the
prep function instead. The value is really that it allows us to begin
to separate the ULDs from the SCSI mid layer (as long as they don't use
any core functions---which is hard at the moment---a ULD doesn't even
need SCSI to bind).
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
A BUSY status returned on a write request results in a stale residual
being returned when the write ultimately successfully completes.
This can be reproduced as follows:
1) issue immediate mode rewind to scsi tape drive
2) issue write request
The tape drive returns busy. The low level driver detects underrun and
sets the residual into the scsi command. The low level driver responds
with (DID_OK << 16) | scsi_status. scsi_status is 8, hence
status_byte(result) == 4, i.e., BUSY.
scsi_softirq_done() calls scsi_decide_disposition() which returns
ADD_TO_MLQUEUE. scsi_softirq_done() then calls scsi_queue_insert()
which, on the way to resubmitting the request to the driver, calls
scsi_init_cmd_errh().
The attached patch modifies scsi_init_cmd_errh() to clear the resid
field. This prevents a "stale" residual from being returned when the
scsi command finally completes without a BUSY status.
Signed-off-by: Michael Reed <mdr@sgi.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
sg's may have setup a the buffer with a different length than
the transfer length so we should be using the bufflen passed
in as the request's data len.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
As bi_end_io is only called once when the reqeust is complete,
the 'size' argument is now redundant. Remove it.
Now there is no need for bio_endio to subtract the size completed
from bi_size. So don't do that either.
While we are at it, change bi_end_io to return void.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
ll_back_merge_fn is currently exported to SCSI where is it used,
together with blk_rq_bio_prep, in exactly the same way these
functions are used in __blk_rq_map_user.
So move the common code into a new function (blk_rq_append_bio), and
don't export ll_back_merge_fn any longer.
Signed-off-by: Neil Brown <neilb@suse.de>
diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Our current implementation has a generic set of barrier functions that
go through the SCSI driver model. Realistically, this is unnecessary,
because the only device that can use barriers (sd) can set the flush
functions up at probe or revalidate time. This patch pulls the barrier
functions out of the mid layer and scsi driver model and relocates them
directly in sd.
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Some of the code has been gradually transitioned to using the proper
struct request_queue, but there's lots left. So do a full sweet of
the kernel and get rid of this typedef and replace its uses with
the proper type.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Currently we scale the mempool sizes depending on memory installed
in the machine, except for the bio pool itself which sits at a fixed
256 entry pre-allocation.
There's really no point in "optimizing" this OOM path, we just need
enough preallocated to make progress. A single unit is enough, lets
scale it down to 2 just to be on the safe side.
This patch saves ~150kb of pinned kernel memory on a 32-bit box.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Some targets can return both valid data and sense information.
Always update the request data_len from the SCSI command residual.
Callers should interpret sense data to determine what parts of the
data are valid in case of a CHECK CONDITION status.
Signed-off-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch enhances SCSI error printing by:
- Making use of scsi_print_result() in the completion functions.
- Having scmd_printk() output the disk name (when applicable).
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
* master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (97 commits)
[SCSI] zfcp: removed wrong comment
[SCSI] zfcp: use of uninitialized variable
[SCSI] zfcp: Invalid locking order
[SCSI] aic79xx: use dma_get_required_mask()
[SCSI] aic79xx: fix bracket mismatch in unused macro
[SCSI] BusLogic: Replace 'boolean' by 'bool'
[SCSI] advansys: clean up warnings
[SCSI] 53c7xx: brackets fix in uncompiled code
[SCSI] nsp_cs: remove old scsi code
[SCSI] aic79xx: make ahd_match_scb() static
[SCSI] DAC960: kmalloc->kzalloc/Casting cleanups
[SCSI] scsi_kmap_atomic_sg(): check that local irqs are disabled
[SCSI] Buslogic: local_irq_disable() is redundant after local_irq_save()
[SCSI] aic94xx: update for v28 firmware
[SCSI] scsi_error: Fix lost EH commands
[SCSI] aic94xx: Add default bus reset handler
[SCSI] aic94xx: Remove TMF result code munging
[SCSI] libsas: Add an LU reset mechanism to the error handler
[SCSI] libsas: Don't BUG when connecting two expanders via wide port
[SCSI] st: fix Tape dies if wrong block size used, bug 7919
...
Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the
corresponding "kmem_cache_zalloc()" call.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Roland McGrath <roland@redhat.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: Joel Becker <Joel.Becker@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The KM_BIO_SRC_IRQ kmap slot must be taken with local irqs disabled. Add a
check into scsi for this.
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
scsi_retry_command only has a single caller, so there is no point
in having this function. Additionally the memset of the sense
buffer it does is entirely superflous as scsi_request_fn already
calls scsi_init_cmd_errh to perform this memset before the command
is reissued.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
We have full flexibility of merging parameters now, so we can remove the
hooks that define back/front/request merge strategies. Nobody is using
them anymore.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's a file system thing, for block requests the only size used in the
io paths is ->data_len as it is in bytes, not sectors.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Replace all uses of kmem_cache_t with struct kmem_cache.
The patch was generated using the following script:
#!/bin/sh
#
# Replace one string by another in all the kernel sources.
#
set -e
for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
quilt add $file
sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
mv /tmp/$$ $file
quilt refresh
done
The script was run like this
sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the needed changes to the scsi-ml for the target
mode support.
Note, per the last review we moved almost all the fields we added
to the scsi_cmnd to our internal data structure which we are going
to try and kill off when we can replace it with support from other
parts of the kernel.
The one field we left on was the offset variable. This is needed to handle
the case where the target gets request that is so large that it cannot
execute it in one dma operation. So max_secotors or a segment limit may
limit the size of the transfer. In this case our tgt core code will
break up the command into managable transfers and send them to the
LLD one at a time. The offset is then used to tell the LLD where in
the command we are at. Is there another field on the scsi_cmd for
that?
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
ATAPI devices transfer fixed number of bytes for CDBs (12 or 16). Some
ATAPI devices choke when shorter CDB is used and the left bytes contain
garbage. Block SG_IO cleared left bytes but SCSI SG_IO didn't. This patch
makes SCSI SG_IO clear it and simplify CDB clearing in block SG_IO.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Mathieu Fluhr <mfluhr@nero.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Douglas Gilbert <dougg@torque.net>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: <stable@kernel.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I wanted to add some BUG checks to scsi_prep_fn to make sure no one
sends us a non-sg command, but this function is a horrible mess.
So I decided to detangle the function and document what the valid
cases are. While doing that I found that REQ_TYPE_SPECIAL commands
aren't used by the SCSI layer anymore and we can get rid of the code
handling them.
The new structure of scsi_prep_fn is:
(1) check if we're allowed to send this command
(2) big switch on cmd_type. For the two valid types call into
a function to set the command up, else error
(3) code to handle error cases
Because FS and BLOCK_PC commands are handled entirely separate after
the patch this introduces a tiny amount of code duplication. This
improves readabiulity though and will help to avoid the bidi command
overhead for FS commands so it's a good thing.
I've tested this on both sata and mptsas.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
In scsi_execute_async()'s error path, a struct scsi_io_context
allocated with kmem_cache_alloc() is kfree()'d. Obviously
kmem_cache_free() should be used instead.
Signed-off-by: Arne Redlich <arne.redlich@xiranet.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.
Signed-off-by: Jens Axboe <axboe@suse.de>
Attached is a patch that should limit a possible recursion that can
lead to a stack overflow like follows:
Kernel stack overflow.
CPU: 3 Not tainted
Process zfcperp0.0.d819
(pid: 13897, task: 000000003e0d8cc8, ksp: 000000003499dbb8)
Krnl PSW : 0404000180000000 000000000030f8b2 (get_device+0x12/0x48)
Krnl GPRS: 00000000135a1980 000000000030f758 000000003ed6c1e8 0000000000000005
0000000000000000 000000000044a780 000000003dbf7000 0000000034e15800
000000003621c048 070000003499c108 000000003499c1a0 000000003ed6c000
0000000040895000 00000000408ab630 000000003499c0a0 000000003499c0a0
Krnl Code: a7 fb ff e8 a7 19 00 00 b9 02 00 22 e3 e0 f0 98 00 24 a7 84
Call Trace:
([<000000004089edc2>] scsi_request_fn+0x13e/0x650 [scsi_mod])
[<00000000002c5ff4>] blk_run_queue+0xd4/0x1a4
[<000000004089ff8c>] scsi_queue_insert+0x22c/0x2a4 [scsi_mod]
[<000000004089779a>] scsi_dispatch_cmd+0x8a/0x3d0 [scsi_mod]
[<000000004089f1ec>] scsi_request_fn+0x568/0x650 [scsi_mod]
...
[<000000004089f1ec>] scsi_request_fn+0x568/0x650 [scsi_mod]
[<00000000002c5ff4>] blk_run_queue+0xd4/0x1a4
[<000000004089ff8c>] scsi_queue_insert+0x22c/0x2a4 [scsi_mod]
[<000000004089779a>] scsi_dispatch_cmd+0x8a/0x3d0 [scsi_mod]
[<000000004089f1ec>] scsi_request_fn+0x568/0x650 [scsi_mod]
[<00000000002c5ff4>] blk_run_queue+0xd4/0x1a4
[<000000004089fa9e>] scsi_run_host_queues+0x196/0x230 [scsi_mod]
[<00000000409eba28>] zfcp_erp_thread+0x2638/0x3080 [zfcp]
[<0000000000107462>] kernel_thread_starter+0x6/0xc
[<000000000010745c>] kernel_thread_starter+0x0/0xc
<0>Kernel panic - not syncing: Corrupt kernel stack, can't continue.
This stack overflow occurred during tests on s390 using zfcp.
Recursion depth for this panic was 19.
Usually recursion between blk_run_queue and a request_fn is avoided
using QUEUE_FLAG_REENTER. But this does not help if the scsi stack
tries to flush the starved_list of a scsi_host.
Limit recursion depth when flushing the starved_list
of a scsi_host.
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Currently struct scsi_cmnd has various fields that are used to backup
original data after the corresponding fields have been overridden for
EH commands. This means drivers can easily get at it and misuse it.
Due to the old_ naming this doesn't happen for most of them, but two
that have different names have been used wrong a lot (see previous
patch). Another downside is that they unessecarily bloat the scsi_cmnd
size.
This patch moves them onstack in scsi_send_eh_cmnd to fix those two
issues aswell as allowing future EH fixes like moving the EH command
submissions to use SG lists like everything else.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
There was a logic fault in scsi_io_completion() where zero transfer
commands that complete successfully were sent to the block layer as
not up to date. This patch removes the if (good_bytes > 0) gate
around the successful completion, since zero transfer commands do have
good_bytes == 0.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
If a device gets offlined as a result of the Inquiry sent
during scanning, the following oops can occur. After the
disk gets put into the SDEV_OFFLINE state, the error handler
sends back the failed inquiry, which wakes the thread doing
the scan. This starts a race between the scanning thread
freeing the scsi device and the error handler calling
scsi_run_host_queues to restart the host. Since the disk
is in the SDEV_OFFLINE state, scsi_device_get will still
work, which results in __scsi_iterate_devices getting
a reference to the scsi disk when it shouldn't.
The following execution thread causes the oops:
CPU 0 (scan) CPU 1 (eh)
---------------------------------------------------------
scsi_probe_and_add_lun
....
scsi_eh_offline_sdevs
scsi_eh_flush_done_q
scsi_destroy_sdev
scsi_device_dev_release
scsi_restart_operations
scsi_run_host_queues
__scsi_iterate_devices
get_device
scsi_device_dev_release_usercontext
scsi_run_queue
<---OOPS--->
The patch fixes this by changing the state of the sdev to SDEV_DEL
before doing the final put_device, which should prevent the race
from occurring.
Original oops follows:
Badness in kref_get at lib/kref.c:32
Call Trace:
[C00000002F4476D0] [C00000000000EE20] .show_stack+0x68/0x1b0 (unreliable)
[C00000002F447770] [C00000000037515C] .program_check_exception+0x1cc/0x5a8
[C00000002F447840] [C00000000000446C] program_check_common+0xec/0x100
Exception: 700 at .kref_get+0x10/0x28
LR = .kobject_get+0x20/0x3c
[C00000002F447B30] [C00000002F447BC0] 0xc00000002f447bc0 (unreliable)
[C00000002F447BB0] [C000000000254BDC] .get_device+0x20/0x3c
[C00000002F447C30] [D000000000063188] .scsi_device_get+0x34/0xdc [scsi_mod]
[C00000002F447CC0] [D0000000000633EC] .__scsi_iterate_devices+0x50/0xbc [scsi_mod]
[C00000002F447D60] [D00000000006A910] .scsi_run_host_queues+0x34/0x5c [scsi_mod]
[C00000002F447DF0] [D000000000069054] .scsi_error_handler+0xdb4/0xe44 [scsi_mod]
[C00000002F447EE0] [C00000000007B4E0] .kthread+0x128/0x178
[C00000002F447F90] [C000000000025E84] .kernel_thread+0x4c/0x68
Unable to handle kernel paging request for <7>PCI: Enabling device: (0002:41:01.1), cmd 143
data at address 0x000001b8
Faulting instruction address: 0xd0000000000698e4
sym1: <1010-66> rev 0x1 at pci 0002:41:01.1 irq 216
sym1: No NVRAM, ID 7, Fast-80, LVD, parity checking
sym1: SCSI BUS has been reset.
scsi2 : sym-2.2.2
cpu 0x0: Vector: 300 (Data Access) at [c00000002f447a30]
pc: d0000000000698e4: .scsi_run_queue+0x2c/0x218 [scsi_mod]
lr: d00000000006a904: .scsi_run_host_queues+0x28/0x5c [scsi_mod]
sp: c00000002f447cb0
msr: 9000000000009032
dar: 1b8
dsisr: 40000000
current = 0xc0000000045fecd0
paca = 0xc00000000048ee80
pid = 1123, comm = scsi_eh_1
enter ? for help
[c00000002f447d60] d00000000006a904 .scsi_run_host_queues+0x28/0x5c [scsi_mod]
[c00000002f447df0] d000000000069054 .scsi_error_handler+0xdb4/0xe44 [scsi_mod]
[c00000002f447ee0] c00000000007b4e0 .kthread+0x128/0x178
[c00000002f447f90] c000000000025e84 .kernel_thread+0x4c/0x68
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
We have to be able to remove SCSI devices even when they are suspended, so
QUIESCE -> CANCEL must be a legal state transition. This patch (as727)
adds the transition to the state machine.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch simplifies "good_bytes" computation in sd_rw_intr().
sd: "good_bytes" computation is always done in terms of the resolution
of the device's medium, since after that it is the number of good bytes
we pass around and other layers/contexts (as opposed ot sd) can translate
that to their own resolution (block layer:512). It also makes
scsi_io_completion() processing more straightforward, eliminating the
3rd argument to the function.
It also fixes a couple of bugs like not checking return value,
using "break" instead of "return;", etc.
I've been running with this patch for some time now on a
test (do-it-all) system.
Signed-off-by: Luben Tuikov <ltuikov@yahoo.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
With Achim patch the last user (gdth) is switched away from scsi_request
so we an kill it now. Also disables some code in i2o_scsi that was
broken since the sg driver stopped using scsi_requests.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove
duplicates of the macro.
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The calculation of nr_pages in scsi_req_map_sg() doesn't account for
the fact that the first page could have an offset that pushes the end
of the buffer onto a new page.
Signed-off-by: Bryan Holty <lgeek@frontiernet.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
libata needs to invoke EH without scmd. This patch adds
shost->host_eh_scheduled to implement such behavior.
Currently the only user of this feature is libata and no general
interface is defined. This patch simply adds handling for
host_eh_scheduled where needed and exports scsi_eh_wakeup() to
modules. The rest is upto libata. This is the result of the
following discussion.
http://thread.gmane.org/gmane.linux.scsi/23853/focus=9760
In short, SCSI host is not supposed to know about exceptions unrelated
to specific device or command. Such exceptions should be handled by
transport layer proper. However, the distinction is not essential to
ATA and libata is planning to depart from SCSI, so, for the time
being, libata will be using SCSI EH to handle such exceptions.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Some pioneer DVDs are apparently returning odd "not ready" status
codes that the mid-layer doesn't recognise and so passes back to the
user as errors.
This patch overhauls our not-ready handling and adds transparent retries for:
format in progress
rebuild in progress
recalculation in progress
operation in progress
Long write in progress
self test in progress
The Pioneer was actually returning "long write in progress"
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
drivers/scsi/scsi_lib.c: In function `scsi_kmap_atomic_sg':
drivers/scsi/scsi_lib.c:2394: warning: unsigned int format, different type arg (arg 3)
drivers/scsi/scsi_lib.c:2394: warning: unsigned int format, different type arg (arg 4)
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The current dc395x driver uses PIO to transfer up to 4 bytes which do not
get transferred by DMA (under unclear circumstances). For this the driver
uses page_address() which is broken on highmem. Apart from this the
actual calculation of the virtual address is wrong (even without highmem).
So, e.g., for reading it reads bytes from the driver to a wrong address
and returns wrong data, I guess, for writing it would just output random
data to the device.
The proper fix, as suggested by many, is to dynamically map data using
kmap_atomic(page, KM_BIO_SRC_IRQ) / kunmap_atomic(virt). The reason why it
has not been done until now, although I've done some preliminary patches
more than a year ago was that nobody interested in fixing this problem was
able to reliably reproduce it. Now it changed - with the help from
Sebastian Frei (CC'ed) I was able to trigger the PIO path. Thus, I was
also able to test and debug it.
There are 4 cases when PIO is used in dc395x - data-in / -out with and
without scatter-gather. I was able to reproduce and test only data-in with
and without SG. So, the data-out path is still untested, but it is also
somewhat simpler than the data-in. Fredrik Roubert (also CC'ed) also had
PIO triggering on his system, and in his case it was data-out without SG.
It would be great if he could test the attached patch on his system, but
even if he cannot, I would still request to apply the patch and just wait
if anybody cries...
Implementation: I put 2 new functions in scsi_lib.c and their declarations
in scsi_cmnd.h. I exported them without _GPL, although, I don't feel
strongly about that - not many drivers are likely to use them. But there
is at least one more - I want to use them in tmscsim.c. Whether these are
the right files for the functions and their declarations - not sure
either. Actually, they are not scsi-specific, so, might go somewhere
around other scattergather magic? They are not platform specific either,
and most SG functions are defined under arch/*/... As these issues were
discussed previously there were some more routines suggested to manipulate
scattergather buffers, I think, some of them were needed around
crypto code... So, might be a common place reasonable, like
lib/scattergather.c? I am open here.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
scsi_kill_request() completes requests via normal SCSI completion path
which decrements busy counts; however, requests which get passed to
scsi_kill_request() aren't holding busy counts and scsi_kill_request()
don't increment them before invoking completion path resulting in
incorrect busy counts. Bump up busy counts before invoking completion
path.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Modify well over a dozen mempool users to call mempool_create_slab_pool()
rather than calling mempool_create() with extra arguments, saving about 30
lines of code and increasing readability.
Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In order to use the new execute_in_process_context() API, you have to
provide it with the work storage, which I do in SCSI in scsi_device and
scsi_target, but which also means that we can no longer queue up the
target reaps, so instead I moved the target to a state model which
allows target_alloc to detect if we've received a dying target and wait
for it to be gone. Hopefully, this should also solve the target
namespace race.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Regardless what mode page was asked for, Initio INIC-14x0 and
INIC-2430 always return page 6 without mode page headers. Try to
recognise this as a special case in scsi_mode_sense and setting the
mode sense headers accordingly.
Signed-off-by: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Change the core SCSI code to use kzalloc rather than kmalloc+memset
where possible.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Fix up an off by one error in calculating retries for scsi
commands. This bug was discovered when an SG_IO request
was sent to scsi core with retries = 0, causing the overall
timeout check to go off in scsi_softirq_done.
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
We have several points in the SCSI stack (primarily for our device
functions) where we need to guarantee process context, but (given the
place where the last reference was released) we cannot guarantee this.
This API gets around the issue by executing the function directly if
the caller has process context, but scheduling a workqueue to execute
in process context if the caller doesn't have it. Unfortunately, it
requires memory allocation in interrupt context, but it's better than
what we have previously. The true solution will require a bit of
re-engineering, so isn't appropriate for 2.6.16.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
When the scsi_execute_async interface was added it ended up reducing
the flexibility of userspace to send arbitrary scsi commands through
sg using SG_IO. The SG_IO interface allows userspace to specify the
CDB length. This is now ignored in scsi_execute_async and it is
guessed using the COMMAND_SIZE macro, which is not always correct,
particularly for vendor specific commands. This patch adds a cmd_len
parameter to the scsi_execute_async interface to allow the caller
to specify the length of the CDB.
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
LLDDs should never see REQ_BLOCK_PC requests, we can handle them just
fine in the core code. There is a small behaviour change in that some
check in sr's rw_intr are bypassed, but I consider the old behaviour
a bug.
Mike found this cleanup opportunity and provdided early patches, so all
the credit goes to him, even if I redid the patches from scratch beause
that was easier than forward-porting the old patches.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch moves the SCSI softirq handling to the block layer version.
There should be no functional changes.
Signed-off-by: Jens Axboe <axboe@suse.de>
All ordered request related stuff delegated to HLD. Midlayer
now doens't deal with ordered setting or prepare_flush
callback. sd.c updated to deal with blk_queue_ordered
setting. Currently, ordered tag isn't used as SCSI midlayer
cannot guarantee request ordering.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
add @uptodate argument to end_that_request_last() and @error
to rq_end_io_fn(). there's no generic way to pass error code
to request completion function, making generic error handling
of non-fs request difficult (rq->errors is driver-specific and
each driver uses it differently). this patch adds @uptodate
to end_that_request_last() and @error to rq_end_io_fn().
for fs requests, this doesn't really matter, so just using the
same uptodate argument used in the last call to
end_that_request_first() should suffice. imho, this can also
help the generic command-carrying request jens is working on.
Signed-off-by: tejun heo <htejun@gmail.com>
Signed-Off-By: Jens Axboe <axboe@suse.de>
- export __blk_put_request and blk_execute_rq_nowait
needed for async REQ_BLOCK_PC requests
- seperate max_hw_sectors and max_sectors for block/scsi_ioctl.c and
SG_IO bio.c helpers per Jens's last comments. Since block/scsi_ioctl.c SG_IO was
already testing against max_sectors and SCSI-ml was setting max_sectors and
max_hw_sectors to the same value this does not change any scsi SG_IO behavior. It only
prepares ll_rw_blk.c, scsi_ioctl.c and bio.c for when SCSI-ml begins to set
a valid max_hw_sectors for all LLDs. Today if a LLD does not set it
SCSI-ml sets it to a safe default and some LLDs set it to a artificial low
value to overcome memory and feedback issues.
Note: Since we now cap max_sectors to BLK_DEF_MAX_SECTORS, which is 1024,
drivers that used to call blk_queue_max_sectors with a large value of
max_sectors will now see the fs requests capped to BLK_DEF_MAX_SECTORS.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Add kmemcache of scsi io contexts.
In the future when we finalize on where these functions will live
we can add a mempool for it and do a bioset for out REQ_BLOCK_PC
bios. This is needed becuase the dm-multipath handlers will
want to use the scsi_exectute* functions for failover and we cannot
have them and the bio device allocating from the same mempool.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
sd does not allow scsi_io_completion to retry commands for
SG_IO requests, and it make sense that it should not happen for st
SG_IO commands too. If for st we hit the bottom of scsi_io_completion
we will probably screw things up pretty bad. This patch returns to the
block layer that the whole command completed and relies on the caller to check
the request errors field. For initialization commands like in sd, this adds
the previous behavior where scsi_io_completion did not process the error.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
For tape we need to control the retries. This patch adds a retries
counter on the request for REQ_BLOCK_PC commands originating from
scsi_execute* to use. REQ_BLOCK_PC commands comming from the block
layer SG_IO path continue to use the retires set in the ULD init_command.
(scsi_execute* does not set the gendisk so we do not execute
the init_command in that path).
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Add scsi helpers to create really-large-requests and convert
scsi-ml to scsi_execute_async().
Per Jens's previous comments, I placed this function in scsi_lib.c.
I made it follow all the queue's limits - I think I did at least :), so
I removed the warning on the function header.
I think the scsi_execute_* functions should eventually take a request_queue
and be placed some place where the dm-multipath hw_handler can use them
if that failover code is going to stay in the kernel. That conversion
patch will be sent in another mail though.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This reverts commit 1b0997f561, which in
turn reverted 34ea80ec6a (which is thus
re-instated).
Quoth James Bottomley:
"All it's doing is deferring the device_put() from the
scsi_put_command() to after the scsi_run_queue(), which doesn't fix
the sleep while atomic problem of the device release method. In both
cases we still get the semaphore in atomic context problem which is
caused by scsi_reap_target() doing a device_del(), which I assumed
(wrongly) was valid from atomic context."
who also promised to fix scsi_reap_target().
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This reverts commit 34ea80ec6a.
It does a put_device() from softirq context, which is bad since it gets
a semaphore for reading.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The problem is that scsi_run_queue is called from scsi_next_command()
after doing a scsi_put_command. If the command was the only thing
holding the reference on the scsi_device then the resulting device put
will tear down the block queue. Fix this by taking a reference to the
device and holding it around scsi_run_queue()
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This function has been superceeded by the block request based interfaces
and is unused (except for the uncompilable cpqfc driver).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This should eliminate (at least in the mid layer) to make numeric
assumptions about any of the enumeration variables. As a side effect,
it will also make all the messages consistent and line us up nicely for
the error logging strategy (if it ever shows itself again).
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
When a request is deferred in scsi_init_io because the sg table could not
be allocated, the associated scsi_cmnd is not released and the request is
not marked with REQ_DONTPREP. When the command is retried, if
scsi_prep_fn decides to kill it then the scsi_cmnd will never be released.
This patch (as573) changes scsi_init_io so that it calls scsi_put_command
before deferring a request.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
We fix the oops by enforcing the host state model. There have also
been two extra states added: SHOST_CANCEL_RECOVERY and
SHOST_DEL_RECOVERY so we can take the model through host removal while
the recovery thread is active.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
I found one other thing that needs to be fixed. The call to
scsi_release_buffers in scsi_unprep_request causes an oops, because the
sgtable has already been freed in scsi_io_completion. The following patch
is needed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
On Wed, 2005-09-14 at 18:06 +1000, Anton Blanchard wrote:
> And in particular it looks like the scsi_unprep_request in
> scsi_queue_insert is causing it. The following patch fixes the boot
> problems on the vscsi machine:
OK, my fault. Your fix is almost correct .. I was going to do this
eventually, honest, because there's no need to unprep and reprep a
command that comes in through scsi_queue_insert().
However, I decided to leave it in to exercise the scsi_unprep_request()
path just to make sure it was working. What's happening, I think, is
that we also use this path for retries. Since we kill and reget the
command each time, the retries decrement is never seen, so we're
retrying forever.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
