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  1. 27 3月, 2008 2 次提交
    • T
      SVCRDMA: Check num_sge when setting LAST_CTXT bit · c8237a5f
      由 Tom Tucker 提交于 
      The RDMACTXT_F_LAST_CTXT bit was getting set incorrectly
when the last chunk in the read-list spanned multiple pages. This
resulted in a kernel panic when the wrong context was used to
build the RPC iovec page list.

RDMA_READ is used to fetch RPC data from the client for
NFS_WRITE requests. A scatter-gather is used to map the
advertised client side buffer to the server-side iovec and
associated page list.

WR contexts are used to convey which scatter-gather entries are
handled by each WR. When the write data is large, a single RPC may
require multiple RDMA_READ requests so the contexts for a single RPC
are chained together in a linked list. The last context in this list
is marked with a bit RDMACTXT_F_LAST_CTXT so that when this WR completes,
the CQ handler code can enqueue the RPC for processing.

The code in rdma_read_xdr was setting this bit on the last two
contexts on this list when the last read-list chunk spanned multiple
pages. This caused the svc_rdma_recvfrom logic to incorrectly build
the RPC and caused the kernel to crash because the second-to-last
context doesn't contain the iovec page list.

Modified the condition that sets this bit so that it correctly detects
the last context for the RPC.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Tested-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c8237a5f
    • L
      Revert "PCI: remove transparent bridge sizing" · 12c22d6e
      由 Linus Torvalds 提交于 
      This reverts commit 8fa5913d, which
caused various interesting problems for people, including wrong resource
allocations.  See for example bugzilla entry "2.6.25-rc2: ohci1394
problem (MMIO broken)" at

	http://bugzilla.kernel.org/show_bug.cgi?id=10080

And Gary Hade says:

 "The same change had also exposed an issue reported by Paul Martin that
  has been causing an Oops while hotplugging ThinkPads to a ThinkPad
  Dock II.  See

	http://lkml.org/lkml/2008/2/19/405
	http://bugzilla.kernel.org/show_bug.cgi?id=9961

  I have a fix for the ThinkPad docking Oops but if the issue being
  discussed here is caused by the transparent bridge sizing removal
  change I totally agree that it should be reverted."

  The transparent bridge sizing removal change was motivated by
  insufficient PCI memory resource for a transparent bridge window that
  was being created as a result of expansion ROM(s) being included in
  the transparent bridge sizing calculations.

  A later "PCI: Remove default PCI expansion ROM memory allocation"
  change ( re: http://lkml.org/lkml/2007/12/11/361 ) removes the
  expansion ROM(s) from the transparent bridge sizing calculations which
  actually resolves the original issue in a different manner.  So, even
  if the "PCI: remove transparent bridge sizing" is not problematic it
  is no longer needed anyway."
Identified-by: NIvan Kokshaysky <ink@jurassic.park.msu.ru>
Tested-by: NThomas Meyer <thomas@m3y3r.de>
Acked-by: NGary Hade <garyhade@us.ibm.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      12c22d6e
  3. 26 3月, 2008 4 次提交
  5. 25 3月, 2008 34 次提交