linux-toradex.git/drivers/block, branch v3.14.3

mtip32xx: mtip_async_complete() bug fixes

2014-05-06T14:59:34+00:00

commit 5eb9291c36c7d71d7c6c832d5a4f551eb8ac015d upstream.

This patch fixes 2 issues in the fast completion path:
1) Possible double completions / double dma_unmap_sg() calls due to lack
of atomicity in the check and subsequent dereference of the upper layer
callback function. Fixed with cmpxchg before unmap and callback.
2) Regression in unaligned IO constraining workaround for p420m devices.
Fixed by checking if IO is unaligned and using proper semaphore if so.

Signed-off-by: Sam Bradshaw 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

mtip32xx: Unmap the DMA segments before completing the IO request

2014-05-06T14:59:34+00:00

commit 368c89d7ac70f937c93cd6f3b65bcfdfb3ba794f upstream.

If the buffers are unmapped after completing a request, then stale data
might be in the request.

Signed-off-by: Felipe Franciosi 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

mtip32xx: Set queue bounce limit

2014-05-06T14:59:34+00:00

commit 1044b1bb9278f2e656a1a7b63dc24a59506540aa upstream.

We need to set the queue bounce limit during the device initialization to
prevent excessive bouncing on 32 bit architectures.

Signed-off-by: Felipe Franciosi 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

2014-03-29T22:00:27+00:00

Pull Ceph fix from Sage Weil:
 "This drops a bad assert that a few users have been hitting but we've
  only recently been able to track down"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: drop an unsafe assertion

rbd: drop an unsafe assertion

2014-03-29T17:38:14+00:00

Olivier Bonvalet reported having repeated crashes due to a failed
assertion he was hitting in rbd_img_obj_callback():

    Assertion failure in rbd_img_obj_callback() at line 2165:
	rbd_assert(which >= img_request->next_completion);

With a lot of help from Olivier with reproducing the problem
we were able to determine the object and image requests had
already been completed (and often freed) at the point the
assertion failed.

There was a great deal of discussion on the ceph-devel mailing list
about this.  The problem only arose when there were two (or more)
object requests in an image request, and the problem was always
seen when the second request was being completed.

The problem is due to a race in the window between setting the
"done" flag on an object request and checking the image request's
next completion value.  When the first object request completes, it
checks to see if its successor request is marked "done", and if
so, that request is also completed.  In the process, the image
request's next_completion value is updated to reflect that both
the first and second requests are completed.  By the time the
second request is able to check the next_completion value, it
has been set to a value *greater* than its own "which" value,
which caused an assertion to fail.

Fix this problem by skipping over any completion processing
unless the completing object request is the next one expected.
Test only for inequality (not >=), and eliminate the bad
assertion.

Tested-by: Olivier Bonvalet 
Signed-off-by: Alex Elder 
Reviewed-by: Sage Weil 
Reviewed-by: Ilya Dryomov

mtip32xx: fix bad use of smp_processor_id()

2014-03-10T20:32:47+00:00

mtip_pci_probe() dumps the current CPU when loaded, but it does
so in a preemptible context. Hence smp_processor_id() correctly
warns:

BUG: using smp_processor_id() in preemptible [00000000] code: systemd-udevd/155
caller is mtip_pci_probe+0x53/0x880 [mtip32xx]

Switch to raw_smp_processor_id(), since it's just informational
and persistent accuracy isn't important.

Signed-off-by: Jens Axboe

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

2014-03-07T17:59:44+00:00

Pull block fixes from Jens Axboe:
 "Small collection of fixes for 3.14-rc. It contains:

   - Three minor update to blk-mq from Christoph.

   - Reduce number of unaligned (< 4kb) in-flight writes on mtip32xx to
     two.  From Micron.

   - Make the blk-mq CPU notify spinlock raw, since it can't be a
     sleeper spinlock on RT.  From Mike Galbraith.

   - Drop now bogus BUG_ON() for bio iteration with blk integrity.  From
     Nic Bellinger.

   - Properly propagate the SYNC flag on requests. From Shaohua"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: add REQ_SYNC early
  rt,blk,mq: Make blk_mq_cpu_notify_lock a raw spinlock
  bio-integrity: Drop bio_integrity_verify BUG_ON in post bip->bip_iter world
  blk-mq: support partial I/O completions
  blk-mq: merge blk_mq_insert_request and blk_mq_run_request
  blk-mq: remove blk_mq_alloc_rq
  mtip32xx: Reduce the number of unaligned writes to 2

zram: avoid null access when fail to alloc meta

2014-03-04T15:55:49+00:00

zram_meta_alloc could fail so caller should check it.  Otherwise, your
system will hang.

Signed-off-by: Minchan Kim 
Acked-by: Jerome Marchand 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: close PageTail race

2014-03-04T15:55:47+00:00

Commit bf6bddf1924e ("mm: introduce compaction and migration for
ballooned pages") introduces page_count(page) into memory compaction
which dereferences page->first_page if PageTail(page).

This results in a very rare NULL pointer dereference on the
aforementioned page_count(page).  Indeed, anything that does
compound_head(), including page_count() is susceptible to racing with
prep_compound_page() and seeing a NULL or dangling page->first_page
pointer.

This patch uses Andrea's implementation of compound_trans_head() that
deals with such a race and makes it the default compound_head()
implementation.  This includes a read memory barrier that ensures that
if PageTail(head) is true that we return a head page that is neither
NULL nor dangling.  The patch then adds a store memory barrier to
prep_compound_page() to ensure page->first_page is set.

This is the safest way to ensure we see the head page that we are
expecting, PageTail(page) is already in the unlikely() path and the
memory barriers are unfortunately required.

Hugetlbfs is the exception, we don't enforce a store memory barrier
during init since no race is possible.

Signed-off-by: David Rientjes 
Cc: Holger Kiehl 
Cc: Christoph Lameter 
Cc: Rafael Aquini 
Cc: Vlastimil Babka 
Cc: Michal Hocko 
Cc: Mel Gorman 
Cc: Andrea Arcangeli 
Cc: Rik van Riel 
Cc: "Kirill A. Shutemov" 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mtip32xx: Reduce the number of unaligned writes to 2

2014-02-18T22:49:17+00:00

After several experiments, deduced the the optimal number of unaligned
writes to be 2. Changing the value accordingly.

Signed-off-by: Asai Thambi S P 
Signed-off-by: Sam Bradshaw 
Signed-off-by: Jens Axboe