linux-stable.git/include/linux, branch linux-2.6.29.y

IB/mlx4: Add strong ordering to local inval and fast reg work requests

2009-07-02T23:40:46+00:00

commit 2ac6bf4ddc87c3b6b609f8fa82f6ebbffeac12f4 upstream.

The ConnectX Programmer's Reference Manual states that the "SO" bit
must be set when posting Fast Register and Local Invalidate send work
requests.  When this bit is set, the work request will be executed
only after all previous work requests on the send queue have been
executed.  (If the bit is not set, Fast Register and Local Invalidate
WQEs may begin execution too early, which violates the defined
semantics for these operations)

This fixes the issue with NFS/RDMA reported in


Signed-off-by: Jack Morgenstein 
Signed-off-by: Roland Dreier 
Signed-off-by: Greg Kroah-Hartman

firmware_map: fix hang with x86/32bit

2009-07-02T23:40:35+00:00

commit 3b0fde0fac19c180317eb0601b3504083f4b9bf5 upstream.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13484

Peer reported:
| The bug is introduced from kernel 2.6.27, if E820 table reserve the memory
| above 4G in 32bit OS(BIOS-e820: 00000000fff80000 - 0000000120000000
| (reserved)), system will report Int 6 error and hang up. The bug is caused by
| the following code in drivers/firmware/memmap.c, the resource_size_t is 32bit
| variable in 32bit OS, the BUG_ON() will be invoked to result in the Int 6
| error. I try the latest 32bit Ubuntu and Fedora distributions, all hit this
| bug.
|======
|static int firmware_map_add_entry(resource_size_t start, resource_size_t end,
|                  const char *type,
|                  struct firmware_map_entry *entry)

and it only happen with CONFIG_PHYS_ADDR_T_64BIT is not set.

it turns out we need to pass u64 instead of resource_size_t for that.

[akpm@linux-foundation.org: add comment]
Reported-and-tested-by: Peer Chen 
Signed-off-by: Yinghai Lu 
Cc: Ingo Molnar 
Acked-by: H. Peter Anvin 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ptrace: fix possible zombie leak on PTRACE_DETACH

2009-06-15T16:40:20+00:00

commit 4576145c1ecdaaea9ef8976a48335206aa1ebf91 upstream.

When ptrace_detach() takes tasklist, the tracee can be SIGKILL'ed.  If it
has already passed exit_notify() we can leak a zombie, because a) ptracing
disables the auto-reaping logic, and b) ->real_parent was not notified
about the child's death.

ptrace_detach() should follow the ptrace_exit's logic, change the code
accordingly.

Signed-off-by: Oleg Nesterov 
Cc: Jerome Marchand 
Cc: Roland McGrath 
Tested-by: Denys Vlasenko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2: fix i_mutex locking in ocfs2_splice_to_file()

2009-05-18T23:35:25+00:00

commit 328eaaba4e41a04c1dc4679d65bea3fee4349d86 upstream.

Rearrange locking of i_mutex on destination and call to
ocfs2_rw_lock() so locks are only held while buffers are copied with
the pipe_to_file() actor, and not while waiting for more data on the
pipe.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

splice: split up __splice_from_pipe()

2009-05-18T23:35:21+00:00

commit b3c2d2ddd63944ef2a1e4a43077b602288107e01 upstream.

Split up __splice_from_pipe() into four helper functions:

  splice_from_pipe_begin()
  splice_from_pipe_next()
  splice_from_pipe_feed()
  splice_from_pipe_end()

splice_from_pipe_next() will wait (if necessary) for more buffers to
be added to the pipe.  splice_from_pipe_feed() will feed the buffers
to the supplied actor and return when there's no more data available
(or if all of the requested data has been copied).

This is necessary so that implementations can do locking around the
non-waiting splice_from_pipe_feed().

This patch should not cause any change in behavior.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

mm: page_mkwrite change prototype to match fault

2009-05-18T23:35:02+00:00

commit c2ec175c39f62949438354f603f4aa170846aabb upstream.

Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags.  There should be no functional change.

This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg.  virtual_address to the
driver, which might be important in some special cases).

This is required for a subsequent fix.  And will also make it easier to
merge page_mkwrite() with fault() in future.

Signed-off-by: Nick Piggin 
Cc: Chris Mason 
Cc: Trond Myklebust 
Cc: Miklos Szeredi 
Cc: Steven Whitehouse 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Artem Bityutskiy 
Cc: Felix Blyakher 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Fix for enabling branch profiling makes sparse unusable

2009-05-18T23:34:41+00:00

commit d9ad8bc0ca823705413f75b50c442a88cc518b35 upstream.

One of the changes between kernels 2.6.28 and 2.6.29 is that a branch profiler
has been added for if() statements. Unfortunately this patch makes the sparse
output unusable with CONFIG_TRACE_BRANCH_PROFILING=y: when branch profiling is
enabled, sparse prints so much false positives that the real issues are no
longer visible. This behavior can be reproduced as follows:
* enable CONFIG_TRACE_BRANCH_PROFILING, e.g. by running make allyesconfig or
  make allmodconfig.
* run make C=2

Result: a huge number of the following sparse warnings.
...
include/linux/cpumask.h:547:2: warning: symbol '______r' shadows an earlier one
include/linux/cpumask.h:547:2: originally declared here
...

The patch below fixes this by disabling branch profiling while analyzing the
kernel code with sparse.

This patch is already included in 2.6.30-rc1 -- see also
http://lkml.org/lkml/2009/4/5/120.

Signed-off-by: Bart Van Assche 
Cc: Andrew Morton 
Cc: Steven Rostedt 
LKML-Reference: <200904051620.02311.bart.vanassche@gmail.com>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

mm: fix Committed_AS underflow on large NR_CPUS environment

2009-05-08T22:45:11+00:00

commit 00a62ce91e554198ef28234c91c36f850f5a3bc9 upstream

The Committed_AS field can underflow in certain situations:

>         # while true; do cat /proc/meminfo  | grep _AS; sleep 1; done | uniq -c
>               1 Committed_AS: 18446744073709323392 kB
>              11 Committed_AS: 18446744073709455488 kB
>               6 Committed_AS:    35136 kB
>               5 Committed_AS: 18446744073709454400 kB
>               7 Committed_AS:    35904 kB
>               3 Committed_AS: 18446744073709453248 kB
>               2 Committed_AS:    34752 kB
>               9 Committed_AS: 18446744073709453248 kB
>               8 Committed_AS:    34752 kB
>               3 Committed_AS: 18446744073709320960 kB
>               7 Committed_AS: 18446744073709454080 kB
>               3 Committed_AS: 18446744073709320960 kB
>               5 Committed_AS: 18446744073709454080 kB
>               6 Committed_AS: 18446744073709320960 kB

Because NR_CPUS can be greater than 1000 and meminfo_proc_show() does
not check for underflow.

But NR_CPUS proportional isn't good calculation.  In general,
possibility of lock contention is proportional to the number of online
cpus, not theorical maximum cpus (NR_CPUS).

The current kernel has generic percpu-counter stuff.  using it is right
way.  it makes code simplify and percpu_counter_read_positive() don't
make underflow issue.

Reported-by: Dave Hansen 
Signed-off-by: KOSAKI Motohiro 
Cc: Eric B Munson 
Cc: Mel Gorman 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

New locking/refcounting for fs_struct

2009-05-08T22:45:08+00:00

commit 498052bba55ecaff58db6a1436b0e25bfd75a7ff upstream.

* all changes of current->fs are done under task_lock and write_lock of
  old fs->lock
* refcount is not atomic anymore (same protection)
* its decrements are done when removing reference from current; at the
  same time we decide whether to free it.
* put_fs_struct() is gone
* new field - ->in_exec.  Set by check_unsafe_exec() if we are trying to do
  execve() and only subthreads share fs_struct.  Cleared when finishing exec
  (success and failure alike).  Makes CLONE_FS fail with -EAGAIN if set.
* check_unsafe_exec() may fail with -EAGAIN if another execve() from subthread
  is in progress.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

Take fs_struct handling to new file (fs/fs_struct.c)

2009-05-08T22:45:07+00:00

commit 3e93cd671813e204c258f1e6c797959920cf7772 upstream.

Pure code move; two new helper functions for nfsd and daemonize
(unshare_fs_struct() and daemonize_fs_struct() resp.; for now -
the same code as used to be in callers).  unshare_fs_struct()
exported (for nfsd, as copy_fs_struct()/exit_fs() used to be),
copy_fs_struct() and exit_fs() don't need exports anymore.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman