that provided by the block layer
ATA requires that all DMA transfers begin and end on word boundaries.
Because of this, a large amount of machinery grew up in ide to adjust
scatterlists on this basis. However, as of 2.5, the block layer has a
dma_alignment variable which ensures both the beginning and length of a
DMA transfer are aligned on the dma_alignment boundary. Although the
block layer does adjust the beginning of the transfer to ensure this
happens, it doesn't actually adjust the length, it merely makes sure
that space is allocated for transfers beyond the declared length. The
upshot of this is that scatterlists may be padded to any size between
the actual length and the length adjusted to the dma_alignment safely
knowing that memory is allocated in this region.
Right at the moment, SCSI takes the default dma_aligment which is on a
512 byte boundary. Note that this aligment only applies to transfers
coming in from user space. However, since all kernel allocations are
automatically aligned on a minimum of 32 byte boundaries, it is safe to
adjust them in this manner as well.
tj: * Adjusting sg after padding is done in block layer. Make libata
set queue alignment correctly for ATAPI devices and drop broken
sg mangling from ata_sg_setup().
* Use request->raw_data_len for ATAPI transfer chunk size.
* Killed qc->raw_nbytes.
* Separated out killing qc->n_iter.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Clear drain buffer before chaining if the command in question is a
write.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Draining shouldn't be done for commands where overflow may indicate
data integrity issues. Add dma_drain_needed callback to
request_queue. Drain buffer is appened iff this function returns
non-zero.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.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>
DMA start address and transfer size alignment for PC requests are
achieved using bio_copy_user() instead of bio_map_user(). This works
because bio_copy_user() always uses full pages and block DMA alignment
isn't allowed to go over PAGE_SIZE.
However, the implementation didn't update the last bio of the request
to make this padding visible to lower layers. This patch makes
blk_rq_map_user() extend the last bio such that it includes the
padding area and the size of area pointed to by the request is
properly aligned.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
For misc ATAPI commands which transfer variable length data to the
host, overflow can occur due to application or hardware bug. Such
overflows can be ignored safely as long as overflow data is properly
drained. libata HSM implementation has this implemented in
__atapi_pio_bytes() and recently updated for 2.6.24-rc but it requires
further improvements. Improve drain logic such that...
* Report overflow errors using ehi desc mechanism instead of printing
directly.
* Properly calculate the number of bytes to be drained considering
actual number of consumed bytes for partial draining.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently we fail if someone requests a valid io scheduler, but it's
modular and not currently loaded. That can happen from a driver init
asking for a different scheduler, or online switching through sysfs
as requested by a user.
This patch makes elevator_get() request_module() to attempt to load
the appropriate module, instead of requiring that done manually.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's cumbersome to browse a radix tree from start to finish, especially
since we modify keys when a process exits. So add a hlist for the single
purpose of browsing over all known cfq_io_contexts, used for exit,
io prio change, etc.
This fixes http://bugzilla.kernel.org/show_bug.cgi?id=9948
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Commit b2e895dbd8 #if 0'ed this code stating:
<-- snip -->
[PATCH] revert blockdev direct io back to 2.6.19 version
Andrew Vasquez is reporting as-iosched oopses and a 65% throughput
slowdown due to the recent special-casing of direct-io against
blockdevs. We don't know why either of these things are occurring.
The patch minimally reverts us back to the 2.6.19 code for a 2.6.20
release.
<-- snip -->
It has since been dead code, and unless someone wants to revive it now
it's time to remove it.
This patch also makes bio_release_pages() static again and removes the
ki_bio_count member from struct kiocb, reverting changes that had been
done for this dead code.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
This patch makes the needlessly global struct def_blk_aops static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
ide-cd: fix missing residual count setting in DMA mode
ht6560b: force prefetch for some devices
ht6560b can only do up to PIO mode 4
linux/hdsmart.h: fix goofups (take 2)
via82cxxx: add new PCI id for cx700
falconide: locking bugfix
MAINTAINERS: update ide-cd maintainer's email address
ide/libata: ST310211A has buggy HPA too
ide: Add missing base addresses for falconide and macide
Clearly this was supposed to be an == not an = in the if statement.
This patch also causes us to stop processing execve args once we have
failed rather than continuing to loop on failure over and over and over.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes the missing residual count setting in DMA mode,
which was introduced during the conversion to blk-end-request.
The residual count could be used by the request submitter.
So if it isn't set correctly, some upper layers does not work.
(e.g. wodim for CD burning.)
The bug is in only DMA mode.
In PIO mode, we are setting the residual count correctly,
so no need to fix.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Reported-by: Andreas Schwab <schwab@suse.de>
Tested-by: Andreas Schwab <schwab@suse.de>
Tested-by: Laura Garcia <nevola@gmail.com>
Tested-by: Borislav Petkov <petkovbb@googlemail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Prefetch needs to be set for some ide devices to work when connected to
a ht6560b interface. This was not always done properly, causing a system
with a HD and CD on the primary interface to not work properly. Or, in
effect, hang hard.
This patch forces prefetch on devices before checking whether it
is necessary to change the settings in the interface
This patch should also be applied to 2.4. I don't currently have a
2.4 tree around.
(also change my email address)
Signed-off-by: Jan Evert van Grootheest <janevert@caiway.nl>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
According to the datasheet, ht6560b only supports up to PIO mode 4.
[bart: manually ported it over 2.6.25-rc2]
Signed-off-by: Jan Evert van Grootheest <janevert@caiway.nl>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Fix goofups of commit 76166952bb
("<linux/hdsmart.h> is not used by kernel code").
Also update include/linux/Kbuild to reflect the fact that hdsmart.h
uses __KERNEL__ ifdefs now.
Reported-by: "Robert P. J. Day" <rpjday@crashcourse.ca>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
commit 8ac4ce742c ("ide: fix host drivers
depending on ide_generic to probe for interfaces (take 2)") moved probing
to falconide but forgot to take care of Atari specific locking - fix it.
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michael Schmitz <schmitz@debian.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
commit 29dd59755a ("ide: remove ide_setup_ports")
forgot to take into account the base addresses for the CONTROL registers for
falconide and macide, as pointed out by Michael Schmitz.
Falconide was tested on Aranym.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michael Schmitz <schmitz@debian.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
