27 Aug, 2008
1 commit
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cmd_filter works only for the block layer SG_IO with SCSI block
devices. It breaks scsi/sg.c, bsg, and the block layer SG_IO with SCSI
character devices (such as st). We hit a kernel crash with them.The problem is that cmd_filter code accesses to gendisk (having struct
blk_scsi_cmd_filter) via inode->i_bdev->bd_disk. It works for only
SCSI block device files. With character device files, inode->i_bdev
leads you to struct cdev. inode->i_bdev->bd_disk->blk_scsi_cmd_filter
isn't safe.SCSI ULDs don't expose gendisk; they keep it private. bsg needs to be
independent on any protocols. We shouldn't change ULDs to expose their
gendisk.This patch moves struct blk_scsi_cmd_filter from gendisk to
request_queue, a common object, which eveyone can access to.The user interface doesn't change; users can change the filters via
/sys/block/. gendisk has a pointer to request_queue so the cmd_filter
code accesses to struct blk_scsi_cmd_filter.Signed-off-by: FUJITA Tomonori
Signed-off-by: Jens Axboe
02 Aug, 2008
1 commit
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blk_plug_device() must be called with the queue lock held, so callers
often just grab and release the lock for that purpose. Add a helper
that does just that.Signed-off-by: Jens Axboe
16 Jul, 2008
2 commits
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* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (80 commits)
ide-floppy: fix unfortunate function naming
ide-tape: unify idetape_create_read/write_cmd
ide: add ide_pc_intr() helper
ide-{floppy,scsi}: read Status Register before stopping DMA engine
ide-scsi: add more debugging to idescsi_pc_intr()
ide-scsi: use pc->callback
ide-floppy: add more debugging to idefloppy_pc_intr()
ide-tape: always log debug info in idetape_pc_intr() if debugging is enabled
ide-tape: add ide_tape_io_buffers() helper
ide-tape: factor out DSC handling from idetape_pc_intr()
ide-{floppy,tape}: move checking of ->failed_pc to ->callback
ide: add ide_issue_pc() helper
ide: add PC_FLAG_DRQ_INTERRUPT pc flag
ide-scsi: move idescsi_map_sg() call out from idescsi_issue_pc()
ide: add ide_transfer_pc() helper
ide-scsi: set drive->scsi flag for devices handled by the driver
ide-{cd,floppy,tape}: remove checking for drive->scsi
ide: add PC_FLAG_ZIP_DRIVE pc flag
ide-tape: factor out waiting for good ireason from idetape_transfer_pc()
ide-tape: set PC_FLAG_DMA_IN_PROGRESS flag in idetape_transfer_pc()
... -
Some uses blk_put_request asymmetrically, that is, they uses it with
requests that not allocated by blk_get_request. As a result,
blk_put_request has a hack to catch a NULL request_queue. Now such
callers are fixed (they use blk_get_request properly). So we can
safely remove the hack in blk_put_request.Signed-off-by: FUJITA Tomonori
Cc: Borislav Petkov
Signed-off-by: Jens Axboe
Signed-off-by: Bartlomiej Zolnierkiewicz
15 Jul, 2008
1 commit
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* 'core/softirq' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
softirq: remove irqs_disabled warning from local_bh_enable
softirq: remove initialization of static per-cpu variable
Remove argument from open_softirq which is always NULL
03 Jul, 2008
2 commits
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Add test_and_clear and test_and_set.
Signed-off-by: Jens Axboe
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Some block devices support verifying the integrity of requests by way
of checksums or other protection information that is submitted along
with the I/O.This patch implements support for generating and verifying integrity
metadata, as well as correctly merging, splitting and cloning bios and
requests that have this extra information attached.See Documentation/block/data-integrity.txt for more information.
Signed-off-by: Martin K. Petersen
Signed-off-by: Jens Axboe
16 Jun, 2008
1 commit
28 May, 2008
1 commit
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In function get_request_wait, the second call to get_request could be
moved to the end of the while loop, because if the first call to
get_request fails, the second call will fail without sleep.Signed-off-by: Zhang Yanmin
Signed-off-by: Jens Axboe
25 May, 2008
1 commit
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As git-grep shows, open_softirq() is always called with the last argument
being NULLblock/blk-core.c: open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL);
kernel/hrtimer.c: open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL);
kernel/rcuclassic.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL);
kernel/rcupreempt.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL);
kernel/sched.c: open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL);
kernel/softirq.c: open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL);
kernel/softirq.c: open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL);
kernel/timer.c: open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL);
net/core/dev.c: open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL);
net/core/dev.c: open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL);This observation has already been made by Matthew Wilcox in June 2002
(http://www.cs.helsinki.fi/linux/linux-kernel/2002-25/0687.html)"I notice that none of the current softirq routines use the data element
passed to them."and the situation hasn't changed since them. So it appears we can safely
remove that extra argument to save 128 (54) bytes of kernel data (text).Signed-off-by: Carlos R. Mafra
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
15 May, 2008
1 commit
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As setting and clearing queue flags now requires that we hold a spinlock
on the queue, and as blk_queue_stack_limits is called without that lock,
get the lock inside blk_queue_stack_limits.For blk_queue_stack_limits to be able to find the right lock, each md
personality needs to set q->queue_lock to point to the appropriate lock.
Those personalities which didn't previously use a spin_lock, us
q->__queue_lock. So always initialise that lock when allocated.With this in place, setting/clearing of the QUEUE_FLAG_PLUGGED bit will no
longer cause warnings as it will be clear that the proper lock is held.Thanks to Dan Williams for review and fixing the silly bugs.
Signed-off-by: NeilBrown
Cc: Dan Williams
Cc: Jens Axboe
Cc: Alistair John Strachan
Cc: Nick Piggin
Cc: "Rafael J. Wysocki"
Cc: Jacek Luczak
Cc: Prakash Punnoor
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 May, 2008
2 commits
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get_part() is fairly expensive, as it O(N) loops over partitions
to find the right one. In lots of normal IO paths we end up looking
up the partition twice, to make matters even worse. Change the
stat add code to accept a passed in partition instead.Signed-off-by: Jens Axboe
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Original patch from Mikulas Patocka
Mike Anderson was doing an OLTP benchmark on a computer with 48 physical
disks mapped to one logical device via device mapper.He found that there was a slowdown on request_queue->lock in function
generic_unplug_device. The slowdown is caused by the fact that when some
code calls unplug on the device mapper, device mapper calls unplug on all
physical disks. These unplug calls take the lock, find that the queue is
already unplugged, release the lock and exit.With the below patch, performance of the benchmark was increased by 18%
(the whole OLTP application, not just block layer microbenchmarks).So I'm submitting this patch for upstream. I think the patch is correct,
because when more threads call simultaneously plug and unplug, it is
unspecified, if the queue is or isn't plugged (so the patch can't make
this worse). And the caller that plugged the queue should unplug it
anyway. (if it doesn't, there's 3ms timeout).Signed-off-by: Mikulas Patocka
Signed-off-by: Jens Axboe
01 May, 2008
1 commit
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__FUNCTION__ is gcc specific, use __func__
Signed-off-by: Harvey Harrison
Cc: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Apr, 2008
5 commits
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This patch changes rq->cmd from the static array to a pointer to
support large commands.We rarely handle large commands. So for optimization, a struct request
still has a static array for a command. rq_init sets rq->cmd pointer
to the static array.Signed-off-by: FUJITA Tomonori
Cc: Jens Axboe
Signed-off-by: Jens Axboe -
This is a preparation for changing rq->cmd from the static array to a
pointer.Signed-off-by: FUJITA Tomonori
Cc: Boaz Harrosh
Cc: Bartlomiej Zolnierkiewicz
Cc: Jens Axboe
Signed-off-by: Jens Axboe -
This rename rq_init() blk_rq_init() and export it. Any path that hands
the request to the block layer needs to call it to initialize the
request.This is a preparation for large command support, which needs to
initialize the request in a proper way (that is, just doing a memset()
will not work).Signed-off-by: FUJITA Tomonori
Cc: Jens Axboe
Signed-off-by: Jens Axboe -
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
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This requires moving rq_init() from get_request() to blk_alloc_request().
The upside is that we can now require an rq_init() from any path that
wishes to hand the request to the block layer.rq_init() will be exported for the code that uses struct request
without blk_get_request.This is a preparation for large command support, which needs to
initialize struct request in a proper way (that is, just doing a
memset() will not work).Signed-off-by: FUJITA Tomonori
Signed-off-by: Jens Axboe
04 Mar, 2008
3 commits
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This patch removes the unused exports of blk_{get,put}_queue.
Signed-off-by: Adrian Bunk
Signed-off-by: Jens Axboe -
The meaning of rq->data_len was changed to the length of an allocated
buffer from the true data length. It breaks SG_IO friends and
bsg. This patch restores the meaning of rq->data_len to the true data
length and adds rq->extra_len to store an extended length (due to
drain buffer and padding).This patch also removes the code to update bio in blk_rq_map_user
introduced by the commit 40b01b9bbdf51ae543a04744283bf2d56c4a6afa.
The commit adjusts bio according to memory alignment
(queue_dma_alignment). However, memory alignment is NOT padding
alignment. This adjustment also breaks SG_IO friends and bsg. Padding
alignment needs to be fixed in a proper way (by a separate patch).Signed-off-by: FUJITA Tomonori
Signed-off-by: Jens Axboe -
kernel-doc for block/:
- add missing parameters
- fix one function's parameter list (remove blank line)
- add 2 source files to docbook for non-exported kernel-doc functionsSigned-off-by: Randy Dunlap
Signed-off-by: Jens Axboe
19 Feb, 2008
2 commits
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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
Cc: James Bottomley
Signed-off-by: Jens Axboe -
request_cachep needlessly became global.
Signed-off-by: Adrian Bunk
Signed-off-by: Jens Axboe
08 Feb, 2008
3 commits
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Removes the now unused old partition statistic code.
Signed-off-by: Jerome Marchand
Signed-off-by: Jens Axboe -
Updates the enhanced partition statistics in generic block layer
besides the disk statistics.Signed-off-by: Jerome Marchand
Signed-off-by: Jens Axboe -
Rearrange fields in cache order and initialize some fields that
we didn't previously init. Remove init of ->completion_data, it's
part of a union with ->hash. Luckily clearing the rb node is the same
as setting it to null!Signed-off-by: Jens Axboe
01 Feb, 2008
2 commits
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Signed-off-by: Jens Axboe
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No point in passing signed integers as the byte count, they can never
be negative.Signed-off-by: Jens Axboe
30 Jan, 2008
6 commits
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Signed-off-by: Jens Axboe
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Signed-off-by: Jens Axboe
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Signed-off-by: Jens Axboe
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Adds files for barrier handling, rq execution, io context handling,
mapping data to requests, and queue settings.Signed-off-by: Jens Axboe
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Seperates the tag and sysfs handling from ll_rw_blk.
Signed-off-by: Jens Axboe
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Then we retain history in blk-core.c
Signed-off-by: Jens Axboe