03 Oct, 2006
1 commit
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Export blkdev_driver_ioctl for device-mapper.
If we get as far as the device-mapper ioctl handler, we know the ioctl is not
a standard block layer BLK* one, so we don't need to check for them a second
time and can call blkdev_driver_ioctl() directly.Signed-off-by: Alasdair G Kergon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Oct, 2006
39 commits
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All on stack DECLARE_COMPLETIONs should be replaced by:
DECLARE_COMPLETION_ONSTACKSigned-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Acked-by: Benjamin Herrenschmidt
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It's too easy for people to shoot themselves in the foot, and it
only makes sense for embedded folks anyway.Signed-off-by: Jens Axboe
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If we share the tag map between two or more queues, then we cannot
use __set_bit() to set the bit. In fact we need to make sure we
atomically acquire this tag, so loop using test_and_set_bit() to
protect from that.Noticed by Mike Christie
Signed-off-by: Jens Axboe
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As people often look for the copyright in files to see who to mail,
update the link to a neutral one.Signed-off-by: Jens Axboe
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Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.Signed-Off-By: David Howells
Signed-off-by: Jens Axboe -
This patch kills a few lines of code in blktrace by making use of
on_each_cpu().Signed-off-by: Martin Peschke
Signed-off-by: Jens Axboe -
We don't need to disable irqs to clear current->io_context, it is protected
by ->alloc_lock. Even IF it was possible to submit I/O from IRQ on behalf of
current this irq_disable() can't help: current_io_context() will re-instantiate
->io_context after irq_enable().We don't need task_lock() or local_irq_disable() to clear ioc->task. This can't
prevent other CPUs from playing with our io_context anyway.Signed-off-by: Oleg Nesterov
Signed-off-by: Jens Axboe -
Signed-off-by: Jens Axboe
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Give meta data reads preference over regular reads, as the process
often needs to get that out of the way to do the io it was actually
interested in.Signed-off-by: Jens Axboe
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We can use this information for making more intelligent priority
decisions, and it will also be useful for blktrace.Signed-off-by: Jens Axboe
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It can make sense to set read-ahead larger than a single request.
We should not be enforcing such policy on the user. Additionally,
using the BLKRASET ioctl doesn't impose such a restriction. So
additionally we now expose identical behaviour through the two.Issue also reported by Anton
Signed-off-by: Jens Axboe
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Don't touch the current queues, just make sure that the wanted queue
is selected next. Simplifies the logic.Signed-off-by: Jens Axboe
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CFQ implements this on its own now, but it's really block layer
knowledge. Tells a device queue to start dispatching requests to
the driver, taking care to unplug if needed. Also fixes the issue
where as/cfq will invoke a stopped queue, which we really don't
want.Signed-off-by: Jens Axboe
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No point in having a place holder list just for empty queues, so remove
it. It's not used for anything other than to keep ->cfq_list busy.Signed-off-by: Jens Axboe
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Currently it scales with number of processes in that priority group,
which is potentially not very nice as it's called quite often.
Basically we always need to do tail inserts, except for the case of a
new process. So just mark/detect a queue as such.Signed-off-by: Jens Axboe
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Some were kmalloc_node(), some were still kmalloc(). Change them all to
kmalloc_node().Signed-off-by: Jens Axboe
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Kill a few inlines that bring in too much code to more than one location
Shrinks kernel text by about 300 bytes on 32-bit x86.Signed-off-by: Jens Axboe
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It's ok if the read path is a lot more costly, as long as inc/dec is
really cheap. The inc/dec will happen for each created/freed io context,
while the reading only happens when a disk queue exits.Signed-off-by: Jens Axboe
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It's ok if the read path is a lot more costly, as long as inc/dec is
really cheap. The inc/dec will happen for each created/freed io context,
while the reading only happens when a disk queue exits.Signed-off-by: Jens Axboe
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cfq_exit_lock is protecting two things now:
- The per-ioc rbtree of cfq_io_contexts
- The per-cfqd linked list of cfq_io_contexts
The per-cfqd linked list can be protected by the queue lock, as it is (by
definition) per cfqd as the queue lock is.The per-ioc rbtree is mainly used and updated by the process itself only.
The only outside use is the io priority changing. If we move the
priority changing to not browsing the rbtree, we can remove any locking
from the rbtree updates and lookup completely. Let the sys_ioprio syscall
just mark processes as having the iopriority changed and lazily update
the private cfq io contexts the next time io is queued, and we can
remove this locking as well.Signed-off-by: Jens Axboe
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A collection of little fixes and cleanups:
- We don't use the 'queued' sysfs exported attribute, since the
may_queue() logic was rewritten. So kill it.- Remove dead defines.
- cfq_set_active_queue() can be rewritten cleaner with else if conditions.
- Several places had cfq_exit_cfqq() like logic, abstract that out and
use that.- Annotate the cfqq kmem_cache_alloc() so the allocator knows that this
is a repeat allocation if it fails with __GFP_WAIT set. Allows the
allocator to start freeing some memory, if needed. CFQ already loops for
this condition, so might as well pass the hint down.- Remove cfqd->rq_starved logic. It's not needed anymore after we dropped
the crq allocation in cfq_set_request().- Remove uneeded parameter passing.
Signed-off-by: Jens Axboe
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- Don't assign variables that are only used once.
- Kill spin_lock() prefetching, it's opportunistic at best.
Signed-off-by: Jens Axboe
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It's not needed for anything, so kill the bio passing.
Signed-off-by: Jens Axboe
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After Christophs SCSI change, the only usage left is RQ_ACTIVE
and RQ_INACTIVE. The block layer sets RQ_INACTIVE right before freeing
the request, so any check for RQ_INACTIVE in a driver is a bug and
indicates use-after-free.So kill/clean the remaining users, straight forward.
Signed-off-by: Jens Axboe
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It is always identical to &q->rq, and we only use it for detecting
whether this request came out of our mempool or not. So replace it
with an additional ->flags bit flag.Signed-off-by: Jens Axboe
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As the comments indicates in blkdev.h, we can fold it into ->end_io_data
usage as that is really what ->waiting is. Fixup the users of
blk_end_sync_rq().Signed-off-by: Jens Axboe
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Get rid of the as_rq request type. With the added elevator_private2, we
have enough room in struct request to get rid of any arq allocation/free
for each request.Signed-off-by: Jens Axboe
Signed-off-by: Nick Piggin -
Get rid of the cfq_rq request type. With the added elevator_private2, we
have enough room in struct request to get rid of any crq allocation/free
for each request.Signed-off-by: Jens Axboe
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There's just one flag currently (SYNC), and that one can be grabbed from
the request.Signed-off-by: Jens Axboe
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A big win, we now save an allocation/free on each request! With the
previous rb/hash abstractions, we can just reuse queuelist/donelist
for the FIFO data and be done with it.Signed-off-by: Jens Axboe
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We can track this in struct request.
Signed-off-by: Jens Axboe
Signed-off-by: Nick Piggin -
Saves some space in arq.
Signed-off-by: Jens Axboe
Signed-off-by: Nick Piggin -
Signed-off-by: Jens Axboe
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This removes the rbtree handling from deadline.
Signed-off-by: Jens Axboe
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This removes the rbtree handling from CFQ.
Signed-off-by: Jens Axboe
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This removes the rbtree handling from AS.
Signed-off-by: Jens Axboe
Signed-off-by: Nick Piggin -
The rbtree sort/lookup/reposition logic is mostly duplicated in
cfq/deadline/as, so move it to the elevator core. The io schedulers
still provide the actual rb root, as we don't want to impose any sort
of specific handling on the schedulers.Introduce the helpers and rb_node in struct request to help migrate the
IO schedulers.Signed-off-by: Jens Axboe
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The conditions got reserved. Also make rb_next() and rb_prev() check
for the empty condition.Signed-off-by: Jens Axboe
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Right now, every IO scheduler implements its own backmerging (except for
noop, which does no merging). That results in duplicated code for
essentially the same operation, which is never a good thing. This patch
moves the backmerging out of the io schedulers and into the elevator
core. We save 1.6kb of text and as a bonus get backmerging for noop as
well. Win-win!Signed-off-by: Jens Axboe
