the block layer doesn't set rq->cmd_type on flush requests. By
definition, it should be REQ_TYPE_FS (the lower layers build a command
and interpret the result of it, that is, the block layer doesn't know
the details).
scsi: convert discard to REQ_TYPE_FS from REQ_TYPE_BLOCK_PC
Jens, any reason why this isn't included in your for-2.6.36 yet?
=
From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Subject: [PATCH resend] scsi: convert discard to REQ_TYPE_FS from REQ_TYPE_BLOCK_PC
The block layer (file systems) sends discard requests as REQ_TYPE_FS
(the role of REQ_TYPE_FS is that setting up commands and interpreting
the results). But SCSI-ml treats discard requests as
REQ_TYPE_BLOCK_PC.
scsi-ml can handle discard requests as REQ_TYPE_FS
easily. scsi_setup_discard_cmnd() sets up struct request and the bio
nicely. Only remaining issue is that discard requests can't be
completed partially so we need to modify sd_done.
This conversion also fixes the problem that discard requests aren't
retried when possible (e.g. UNIT ATTENTION).
cciss: cleanup interrupt_not_for_us
In the case of MSI/MSIX interrutps, we don't need to check
if the interrupt is for us, and in the case of the intx interrupt
handler, when checking if the interrupt is for us, we don't need
to check if we're using MSI/MSIX, we know we're not.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
cciss: separate cmd_alloc() and cmd_special_alloc()
cciss: separate cmd_alloc() and cmd_special_alloc()
cmd_alloc() took a parameter which caused it to either allocate
from a pre-allocated pool, or allocate using pci_alloc_consistent.
This parameter is always known at compile time, so this would
be better handled by breaking the function into two functions
and differentiating the cases by function names. Same goes
for cmd_free().
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
cciss: forbid hard reset of 640x boards
The 6402/6404 are two PCI devices -- two Smart Array controllers
-- that fit into one slot. It is possible to reset them independently,
however, they share a battery backed cache module. One of the pair
controls the cache and the 2nd one access the cache through the first
one. If you reset the one controlling the cache, the other one will
not be a happy camper. So we just forbid resetting this conjoined
mess.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
cciss: sanitize max commands
Some controllers might try to tell us they support 0 commands
in performant mode. This is a lie told by buggy firmware.
We have to be wary of this lest we try to allocate a negative
number of command blocks, which will be treated as unsigned,
and get an out of memory condition.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
cciss: Fix hard reset code.
Smart Array controllers newer than the P600 do not honor the
PCI power state method of resetting the controllers. Instead,
in these cases we can get them to reset via the "doorbell" register.
This escaped notice until we began using "performant" mode because
the fact that the controllers did not reset did not normally
impede subsequent operation, and so things generally appeared to
"work". Once the performant mode code was added, if the controller
does not reset, it remains in performant mode. The code immediately
after the reset presumes the controller is in "simple" mode
(which previously, it had remained in simple mode the whole time).
If the controller remains in performant mode any code which presumes
it is in simple mode will not work. So the reset needs to be fixed.
Unfortunately there are some controllers which cannot be reset by
either method. (eg. p800). We detect these cases by noticing that
the controller seems to remain in performant mode even after a
reset has been attempted. In those cases we ignore the controller,
as any commands outstanding on it will result in stale completions.
To sum up, we try to do a better job of resetting the controller if
"reset_devices" is set, and if it doesn't work, we ignore that
controller.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
cciss: Set the performant mode bit in the scsi half of the driver
cciss: Set the performant mode bit in the scsi half of the driver
In a couple of places, the performant mode bit wasn't being set in
the scsi half of the driver, causing commands to seem to hang. Use
enqueue_cmd_and_start_io() where appropriate. This fixes a bug that
echo engage scsi > /proc/driver/cciss/cciss0
would hang.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Daniel Stodden [Fri, 30 Apr 2010 22:01:22 +0000 (22:01 +0000)]
blkfront: Lock blockfront_info during xbdev removal
Same approach as blkfront_closing:
* Grab the bdev safely, holding the info mutex.
* Zap xbdev safely, holding the info mutex.
* Try bdev removal safely, holding bd_mutex.
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Daniel Stodden [Fri, 30 Apr 2010 22:01:19 +0000 (22:01 +0000)]
blkfront: Lock blkfront_info when closing
The bdev .open/.release fops race against backend switches to Closing,
handled by the XenBus thread.
The original code attempted to serialize block device holders and
xenbus only via bd_mutex. This is insufficient, the info->bd pointer
may already be stale (or null) while xenbus tries to bump up the
refcount.
Protect blkfront_info with a dedicated mutex.
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Daniel Stodden [Fri, 30 Apr 2010 22:01:16 +0000 (22:01 +0000)]
blkfront: Fix backtrace in del_gendisk
The call to del_gendisk follows an non-refcounted gd->queue
pointer. We release the last ref in blk_cleanup_queue. Fixed by
reordering releases accordingly.
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Daniel Stodden [Fri, 30 Apr 2010 22:01:15 +0000 (22:01 +0000)]
xenbus: Make xenbus_switch_state transactional
According to the comments, this was how it's been done years ago, but
apparently took an xbt pointer from elsewhere back then. The code was
removed because of consistency issues: cancellation wont't roll back
the saved xbdev->state.
Still, unsolicited writes to the state field remain an issue,
especially if device shutdown takes thread synchronization, and subtle
races cause accidental recreation of the device node.
Fixed by reintroducing the transaction. An internal one is sufficient,
so the xbdev->state value remains consistent.
Also fixes the original hack to prevent infinite recursion. Instead of
bailing out on the first attempt to switch to Closing, checks call
depth now.
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
xen/blkfront: avoid compiler warning from missing cases
Fix:
drivers/block/xen-blkfront.c: In function ‘blkfront_connect’:
drivers/block/xen-blkfront.c:933: warning: enumeration value ‘BLKIF_STATE_DISCONNECTED’ not handled in switch
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
K. Y. Srinivasan [Thu, 11 Mar 2010 21:42:26 +0000 (13:42 -0800)]
xen/front: Propagate changed size of VBDs
Support dynamic resizing of virtual block devices. This patch supports
both file backed block devices as well as physical devices that can be
dynamically resized on the host side.
Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Jan Beulich [Sat, 7 Aug 2010 16:31:12 +0000 (18:31 +0200)]
blkfront: don't access freed struct xenbus_device
Unfortunately commit "blkfront: fixes for 'xm block-detach ... --force'"
still wasn't quite right - there was a reference to freed memory left
from blkfront_closing().
Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Jan Beulich [Sat, 7 Aug 2010 16:28:55 +0000 (18:28 +0200)]
blkfront: fixes for 'xm block-detach ... --force'
Prevent prematurely freeing 'struct blkfront_info' instances (when the
xenbus data structures are gone, but the Linux ones are still needed).
Prevent adding a disk with the same (major, minor) [and hence the same
name and sysfs entries, which leads to oopses] when the previous
instance wasn't fully de-allocated yet.
This still doesn't address all issues resulting from forced detach:
I/O submitted after the detach still blocks forever, likely preventing
subsequent un-mounting from completing. It's not clear to me (not
knowing much about the block layer) how this can be avoided.
Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Ian Campbell [Fri, 4 Dec 2009 15:33:54 +0000 (15:33 +0000)]
xen: use less generic names in blkfront driver.
All Xen frontend drivers have a couple of identically named functions which
makes figuring out which device went wrong from a stacktrace harder than it
needs to be. Rename them to something specificto the device type.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
block: fix problem with sending down discard that isn't of correct granularity
If the queue doesn't have a limit set, or it just set UINT_MAX like
we default to, we coud be sending down a discard request that isn't
of the correct granularity if the block size is > 512b.
Fix this by adjusting max_discard_sectors down to the proper
alignment.
Dave Chinner [Tue, 13 Jul 2010 07:50:50 +0000 (17:50 +1000)]
blkdev: check for valid request queue before issuing flush
Issuing a blkdev_issue_flush() on an unconfigured loop device causes a panic as
q->make_request_fn is not configured. This can occur when trying to mount the
unconfigured loop device as an XFS filesystem. There are no guards that catch
the bio before the request function is called because we don't add a payload to
the bio. Instead, manually check this case as soon as we have a pointer to the
queue to flush.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This restores the changes from "scsi/i2o_block: cleanup ioctl
handling", which accidentally got reverted.
Origignal changelog:
This fixes the ioctl function of the i2o_block driver, which
has multiple problems:
* The BLKI2OSRSTRAT and BLKI2OSWSTRAT commands always return
-ENOTTY on success, where they should return 0.
* Support for 32 bit compat is missing
* The driver should use the .ioctl function and because
.locked_ioctl is going away.
The use of the big kernel lock remains for now, but gets
made explictit in the ioctl function.
Every user of the BKL in the sd driver is the
result of the pushdown from the block layer
into the open/close/ioctl functions.
The only place that used to rely on the BKL is
the sdkp->openers variable, which gets converted
into an atomic_t.
Nothing else seems to rely on the BKL, since the
functions do not touch global data without holding
another lock, and the open/close functions are
still protected from concurrent execution using
the bdev->bd_mutex.
The blkpg_ioctl and blkdev_reread_part access fields of
the bdev and gendisk structures, yet they always do so
under the protection of bdev->bd_mutex, which seems
sufficient.
We only call the functions set_device_ro(),
invalidate_bdev(), sync_filesystem() and sync_blockdev()
while holding the BKL in these commands. All
of these are also done in other code paths without
the BKL, which leads me to the conclusion that
the BKL is not needed here either.
The reason we hold it here is that it was originally
pushed down into the ioctl function from vfs_ioctl.
Arnd Bergmann [Sat, 7 Aug 2010 16:25:34 +0000 (18:25 +0200)]
block: push down BKL into .open and .release
The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.
This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.
The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.
Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.
As a preparation for the removal of the big kernel
lock in the block layer, this removes the BKL
from the common ioctl handling code, moving it
into every single driver still using it.
This fixes the ioctl function of the i2o_block driver, which
has multiple problems:
* The BLKI2OSRSTRAT and BLKI2OSWSTRAT commands always return
-ENOTTY on success, where they should return 0.
* Support for 32 bit compat is missing
* The driver should use the .ioctl function and because
.locked_ioctl is going away.
The use of the big kernel lock remains for now, but gets
made explictit in the ioctl function.
Dave Chinner [Wed, 7 Jul 2010 03:24:08 +0000 (13:24 +1000)]
writeback: Add tracing to write_cache_pages
Add a trace event to the ->writepage loop in write_cache_pages to give
visibility into how the ->writepage call is changing variables within the
writeback control structure. Of most interest is how wbc->nr_to_write changes
from call to call, especially with filesystems that write multiple pages
in ->writepage.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Dave Chinner [Wed, 7 Jul 2010 03:24:07 +0000 (13:24 +1000)]
writeback: Add tracing to balance_dirty_pages
Tracing high level background writeback events is good, but it doesn't
give the entire picture. Add visibility into write throttling to catch IO
dispatched by foreground throttling of processing dirtying lots of pages.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Dave Chinner [Wed, 7 Jul 2010 03:24:06 +0000 (13:24 +1000)]
writeback: Initial tracing support
Trace queue/sched/exec parts of the writeback loop. This provides
insight into when and why flusher threads are scheduled to run. e.g
a sync invocation leaves traces like:
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
SCSI-ml needs a way to mark a request as flush request in
q->prepare_flush_fn because it needs to identify them later (e.g. in
q->request_fn or prep_rq_fn).
queue_flush sets REQ_HARDBARRIER in rq->cmd_flags however the block
layer also sends normal REQ_TYPE_FS requests with REQ_HARDBARRIER. So
SCSI-ml can't use REQ_HARDBARRIER to identify flush requests.
We could change the block layer to clear REQ_HARDBARRIER bit before
sending non flush requests to the lower layers. However, intorudcing
the new flag looks cleaner (surely easier).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: James Bottomley <James.Bottomley@suse.de> Cc: David S. Miller <davem@davemloft.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Alasdair G Kergon <agk@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
block: don't allocate a payload for discard request
Allocating a fixed payload for discard requests always was a horrible hack,
and it's not coming to byte us when adding support for discard in DM/MD.
So change the code to leave the allocation of a payload to the lowlevel
driver. Unfortunately that means we'll need another hack, which allows
us to update the various block layer length fields indicating that we
have a payload. Instead of hiding this in sd.c, which we already partially
do for UNMAP support add a documented helper in the core block layer for it.
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Jens Axboe [Fri, 18 Jun 2010 10:10:18 +0000 (12:10 +0200)]
virtio_blk: add default case to cmd type switch
On compilation, gcc correctly detects that we do not handle
all types:
In function ‘blk_done’:
warning: enumeration value ‘REQ_TYPE_FS’ not handled in switch
warning: enumeration value ‘REQ_TYPE_SENSE’ not handled in switch
warning: enumeration value ‘REQ_TYPE_PM_SUSPEND’ not handled in switch
warning: enumeration value ‘REQ_TYPE_PM_RESUME’ not handled in switch
warning: enumeration value ‘REQ_TYPE_PM_SHUTDOWN’ not handled in switch
warning: enumeration value ‘REQ_TYPE_LINUX_BLOCK’ not handled in switch
warning: enumeration value ‘REQ_TYPE_ATA_TASKFILE’ not handled in switch
warning: enumeration value ‘REQ_TYPE_ATA_PC’ not handled in switch
which is a bit pointless since this is at the end of the request
processessing. Add a default case that just breaks out.
block: unify flags for struct bio and struct request
Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver. There were two flags in the bio that were
missing in the requests: BIO_RW_UNPLUG and BIO_RW_AHEAD. Also I've
renamed two request flags that had a superflous RW in them.
Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests. This allows much easier grepping for different request
types instead of unwinding through macros.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
FUJITA Tomonori [Mon, 31 May 2010 06:59:03 +0000 (15:59 +0900)]
block: kill ISA_DMA_THRESHOLD usage
block uses ISA_DMA_THRESHOLD for BLK_BOUNCE_ISA. Only SCSI uses
ISA_DMA_THRESHOLD for ancient drivers with non-zero
unchecked_isa_dma. Nowadays drivers (and subsystems) use dma_mask
properly instead of ISA_DMA_THRESHOLD.
Documentation/scsi/scsi_mid_low_api.txt says:
unchecked_isa_dma - 1=>only use bottom 16 MB of ram (ISA DMA addressing
restriction), 0=>can use full 32 bit (or better) DMA
address space
So block simply uses DMA_BIT_MASK(24) for BLK_BOUNCE_ISA for SCSI.
FUJITA Tomonori [Thu, 17 Jun 2010 12:58:21 +0000 (14:58 +0200)]
aha1532: remove ISA_DMA_THRESHOLD usage
We can safely remove ISA_DMA_THRESHOLD usage in aha1542. aha1542 uses
ISA_DMA_THRESHOLD to see if:
- the buffers in scatter/list are below 16MB.
- scsi_host is below 16MB.
Both checkings were added in the ancient times but aren't necessary
nowadays since we properly bounce the buffers and allocate scsi_host
below 16MB with non-zero unchecked_isa_dma.
A barrier request should by defintion have priority in get_request
and let the queue be unplugged immediately as it's blocking all forward
progress due to the queue draining.
Most filesystems already get this implicitly by the way how submit_bh
treats the buffer_ordered flag, and gfs2 sets it explicitly. But btrfs
and XFS are still forgetting to set the flag, as is blkdev_issue_flush
and some places in DM/MD.
For XFS on metadata heavy workloads this gives a consistent speedup
in the 2-3% range.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Convert assertions to use WARN(). There are several error checks in the
code for things that should never happen. Convert them to standard
warnings so kerneloops.org will see them.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
The first thing the floppy does is read block 0 to test geometry and to
test for disk presence. If disk is not present this causes a console
warning message about failed I/O. Set flag to silence.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>