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  1. 22 Apr, 2009 10 commits
    • Tejun Heo's avatar
      bio: use bio_kmalloc() in copy/map functions · a9e9dc24
      Tejun Heo authored 
      Impact: remove possible deadlock condition

There is no reason to use mempool backed allocation for map functions.
Also, because kern mapping is used inside LLDs (e.g. for EH), using
mempool backed allocation can lead to deadlock under extreme
conditions (mempool already consumed by the time a request reached EH
and requests are blocked on EH).

Switch copy/map functions to bio_kmalloc().
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      a9e9dc24
    • Tejun Heo's avatar
      bio: fix bio_kmalloc() · 451a9ebf
      Tejun Heo authored 
      Impact: fix bio_kmalloc() and its destruction path

bio_kmalloc() was broken in two ways.

* bvec_alloc_bs() first allocates bvec using kmalloc() and then
  ignores it and allocates again like non-kmalloc bvecs.

* bio_kmalloc_destructor() didn't check for and free bio integrity
  data.

This patch fixes the above problems.  kmalloc patch is separated out
from bio_alloc_bioset() and allocates the requested number of bvecs as
inline bvecs.

* bio_alloc_bioset() no longer takes NULL @bs.  None other than
  bio_kmalloc() used it and outside users can't know how it was
  allocated anyway.

* Define and use BIO_POOL_NONE so that pool index check in
  bvec_free_bs() triggers if inline or kmalloc allocated bvec gets
  there.

* Relocate destructors on top of each allocation function so that how
  they're used is more clear.

Jens Axboe suggested allocating bvecs inline.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      451a9ebf
    • Tejun Heo's avatar
      block: fix queue bounce limit setting · cd0aca2d
      Tejun Heo authored 
      Impact: don't set GFP_DMA in q->bounce_gfp unnecessarily

All DMA address limits are expressed in terms of the last addressable
unit (byte or page) instead of one plus that.  However, when
determining bounce_gfp for 64bit machines in blk_queue_bounce_limit(),
it compares the specified limit against 0x100000000UL to determine
whether it's below 4G ending up falsely setting GFP_DMA in
q->bounce_gfp.

As DMA zone is very small on x86_64, this makes larger SG_IO transfers
very eager to trigger OOM killer.  Fix it.  While at it, rename the
parameter to @dma_mask for clarity and convert comment to proper
winged style.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      cd0aca2d
    • Tejun Heo's avatar
      block: fix SG_IO vector request data length handling · 25636e28
      Tejun Heo authored 
      Impact: fix SG_IO behavior such that it matches the documentation

SG_IO howto says that if ->dxfer_len and sum of iovec disagress, the
shorter one wins.  However, the current implementation returns -EINVAL
for such cases.  Trim iovc if it's longer than ->dxfer_len.

This patch uses iov_*() helpers which take struct iovec * by casting
struct sg_iovec * to it.  sg_iovec is always identical to iovec and
this will be further cleaned up with later patches.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      25636e28
    • Tejun Heo's avatar
      scatterlist: make sure sg_miter_next() doesn't return 0 sized mappings · 23c560a9
      Tejun Heo authored 
      Impact: fix not-so-critical but annoying bug

sg_miter_next() returns 0 sized mapping if there is an zero sized sg
entry in the list or at the end of each iteration.  As the users
always check the ->length field, this bug shouldn't be critical other
than causing unnecessary iteration.

Fix it.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      23c560a9
    • Linus Torvalds's avatar
      Linux 2.6.30-rc3 · 09106974
      Linus Torvalds authored
      09106974
    • Arjan van de Ven's avatar
      driver synchronization: make scsi_wait_scan more advanced · d4d5291c
      Arjan van de Ven authored 
      There is currently only one way for userspace to say "wait for my storage
device to get ready for the modules I just loaded": to load the
scsi_wait_scan module. Expectations of userspace are that once this
module is loaded, all the (storage) devices for which the drivers
were loaded before the module load are present.

Now, there are some issues with the implementation, and the async
stuff got caught in the middle of this: The existing code only
waits for the scsy async probing to finish, but it did not take
into account at all that probing might not have begun yet.
(Russell ran into this problem on his computer and the fix works for him)

This patch fixes this more thoroughly than the previous "fix", which
had some bad side effects (namely, for kernel code that wanted to wait for
the scsi scan it would also do an async sync, which would deadlock if you did
it from async context already.. there's a report about that on lkml):
The patch makes the module first wait for all device driver probes, and then it
will wait for the scsi parallel scan to finish.
Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Tested-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d4d5291c
    • Jonathan Corbet's avatar
      Trivial: fix a typo in slow-work.h · 5dd559f0
      Jonathan Corbet authored 
      Fix a comment typo in slow-work.h

...a trivial mistake, but it will mess up kerneldoc if nothing else.
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5dd559f0
    • David Howells's avatar
      PERCPU: Collect the DECLARE/DEFINE declarations together · 5028eaa9
      David Howells authored 
      Collect the DECLARE/DEFINE declarations together in linux/percpu-defs.h so
that they're in one place, and give them descriptive comments, particularly
the SHARED_ALIGNED variant.

It would be nice to collect these in linux/percpu.h, but that's not possible
without sorting out the severe #include recursion between the x86 arch headers
and the general headers (and possibly other arches too).
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5028eaa9
    • David Howells's avatar
      FRV: Fix the section attribute on UP DECLARE_PER_CPU() · 9b8de747
      David Howells authored 
      In non-SMP mode, the variable section attribute specified by DECLARE_PER_CPU()
does not agree with that specified by DEFINE_PER_CPU().  This means that
architectures that have a small data section references relative to a base
register may throw up linkage errors due to too great a displacement between
where the base register points and the per-CPU variable.

On FRV, the .h declaration says that the variable is in the .sdata section, but
the .c definition says it's actually in the .data section.  The linker throws
up the following errors:

kernel/built-in.o: In function `release_task':
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o

To fix this, DECLARE_PER_CPU() should simply apply the same section attribute
as does DEFINE_PER_CPU().  However, this is made slightly more complex by
virtue of the fact that there are several variants on DEFINE, so these need to
be matched by variants on DECLARE.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9b8de747
  3. 21 Apr, 2009 30 commits