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  1. 18 6月, 2011 1 次提交
    • L
      mm: avoid repeated anon_vma lock/unlock sequences in anon_vma_clone() · bb4aa396
      由 Linus Torvalds 提交于 
      In anon_vma_clone() we traverse the vma->anon_vma_chain of the source
vma, locking the anon_vma for each entry.

But they are all going to have the same root entry, which means that
we're locking and unlocking the same lock over and over again.  Which is
expensive in locked operations, but can get _really_ expensive when that
root entry sees any kind of lock contention.

In fact, Tim Chen reports a big performance regression due to this: when
we switched to use a mutex instead of a spinlock, the contention case
gets much worse.

So to alleviate this all, this commit creates a small helper function
(lock_anon_vma_root()) that can be used to take the lock just once
rather than taking and releasing it over and over again.

We still have the same "take the lock and release" it behavior in the
exit path (in unlink_anon_vmas()), but that one is a bit harder to fix
since we're actually freeing the anon_vma entries as we go, and that
will touch the lock too.
Reported-and-tested-by: NTim Chen <tim.c.chen@linux.intel.com>
Tested-by: NHugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      bb4aa396
  3. 17 6月, 2011 20 次提交
  5. 16 6月, 2011 19 次提交
    • D
      AFS: Use i_generation not i_version for the vnode uniquifier · d6e43f75
      由 David Howells 提交于 
      Store the AFS vnode uniquifier in the i_generation field, not the i_version
field of the inode struct.  i_version can then be given the AFS data version
number.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      d6e43f75
    • D
      AFS: Set s_id in the superblock to the volume name · 2e41ae22
      由 David Howells 提交于 
      Set s_id in the superblock to the name of the AFS volume that this superblock
corresponds to.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      2e41ae22
    • J
      vfs: Fix data corruption after failed write in __block_write_begin() · f9f07b6c
      由 Jan Kara 提交于 
      I've got a report of a file corruption from fsxlinux on ext3. The important
operations to the page were:
mapwrite to a hole
partial write to the page
read - found the page zeroed from the end of the normal write

The culprit seems to be that if get_block() fails in __block_write_begin()
(e.g. transient ENOSPC in ext3), the function does ClearPageUptodate(page).
Thus when we retry the write, the logic in __block_write_begin() thinks zeroing
of the page is needed and overwrites old data.  In fact, I don't see why we
should ever need to zero the uptodate bit here - either the page was uptodate
when we entered __block_write_begin() and it should stay so when we leave it,
or it was not uptodate and noone had right to set it uptodate during
__block_write_begin() so it remains !uptodate when we leave as well. So just
remove clearing of the bit.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      f9f07b6c
    • A
      afs: afs_fill_page reads too much, or wrong data · 5e7f2337
      由 Anton Blanchard 提交于 
      afs_fill_page should read the page that is about to be written but
the current implementation has a number of issues. If we aren't
extending the file we always read PAGE_CACHE_SIZE at offset 0. If we
are extending the file we try to read the entire file.

Change afs_fill_page to read PAGE_CACHE_SIZE at the right offset,
clamped to i_size.

While here, avoid calling afs_fill_page when we are doing a
PAGE_CACHE_SIZE write.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      5e7f2337
    • R
      staging: fix iio builds when IIO_RING_BUFFER is not enabled · e1d76719
      由 Randy Dunlap 提交于 
      Fix build by moving enum list outside of
#ifdef CONFIG_IIO_RING_BUFFER.

  drivers/staging/iio/accel/adis16201_core.c:413: error: 'ADIS16201_SCAN_SUPPLY' undeclared here (not in a function)
  drivers/staging/iio/accel/adis16201_core.c:417: error: 'ADIS16201_SCAN_TEMP' undeclared here (not in a function)
  ..

  drivers/staging/iio/accel/adis16203_core.c:374: error: 'ADIS16203_SCAN_SUPPLY' undeclared here (not in a function)
  drivers/staging/iio/accel/adis16203_core.c:378: error: 'ADIS16203_SCAN_AUX_ADC' undeclared here (not in a function)
  ..
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Acked-by: NJonathan Cameron <jic23@cam.ac.uk>
Cc: linux-iio@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e1d76719
    • A
      VFS: Fix vfsmount overput on simultaneous automount · 8aef1884
      由 Al Viro 提交于 
      [Kudos to dhowells for tracking that crap down]

If two processes attempt to cause automounting on the same mountpoint at the
same time, the vfsmount holding the mountpoint will be left with one too few
references on it, causing a BUG when the kernel tries to clean up.

The problem is that lock_mount() drops the caller's reference to the
mountpoint's vfsmount in the case where it finds something already mounted on
the mountpoint as it transits to the mounted filesystem and replaces path->mnt
with the new mountpoint vfsmount.

During a pathwalk, however, we don't take a reference on the vfsmount if it is
the same as the one in the nameidata struct, but do_add_mount() doesn't know
this.

The fix is to make sure we have a ref on the vfsmount of the mountpoint before
calling do_add_mount().  However, if lock_mount() doesn't transit, we're then
left with an extra ref on the mountpoint vfsmount which needs releasing.
We can handle that in follow_managed() by not making assumptions about what
we can and what we cannot get from lookup_mnt() as the current code does.

The callers of follow_managed() expect that reference to path->mnt will be
grabbed iff path->mnt has been changed.  follow_managed() and follow_automount()
keep track of whether such reference has been grabbed and assume that it'll
happen in those and only those cases that'll have us return with changed
path->mnt.  That assumption is almost correct - it breaks in case of
racing automounts and in even harder to hit race between following a mountpoint
and a couple of mount --move.  The thing is, we don't need to make that
assumption at all - after the end of loop in follow_manage() we can check
if path->mnt has ended up unchanged and do mntput() if needed.

The BUG can be reproduced with the following test program:

	#include <stdio.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <unistd.h>
	#include <sys/wait.h>
	int main(int argc, char **argv)
	{
		int pid, ws;
		struct stat buf;
		pid = fork();
		stat(argv[1], &buf);
		if (pid > 0) wait(&ws);
		return 0;
	}

and the following procedure:

 (1) Mount an NFS volume that on the server has something else mounted on a
     subdirectory.  For instance, I can mount / from my server:

	mount warthog:/ /mnt -t nfs4 -r

     On the server /data has another filesystem mounted on it, so NFS will see
     a change in FSID as it walks down the path, and will mark /mnt/data as
     being a mountpoint.  This will cause the automount code to be triggered.

     !!! Do not look inside the mounted fs at this point !!!

 (2) Run the above program on a file within the submount to generate two
     simultaneous automount requests:

	/tmp/forkstat /mnt/data/testfile

 (3) Unmount the automounted submount:

	umount /mnt/data

 (4) Unmount the original mount:

	umount /mnt

     At this point the kernel should throw a BUG with something like the
     following:

	BUG: Dentry ffff880032e3c5c0{i=2,n=} still in use (1) [unmount of nfs4 0:12]

Note that the bug appears on the root dentry of the original mount, not the
mountpoint and not the submount because sys_umount() hasn't got to its final
mntput_no_expire() yet, but this isn't so obvious from the call trace:

 [<ffffffff8117cd82>] shrink_dcache_for_umount+0x69/0x82
 [<ffffffff8116160e>] generic_shutdown_super+0x37/0x15b
 [<ffffffffa00fae56>] ? nfs_super_return_all_delegations+0x2e/0x1b1 [nfs]
 [<ffffffff811617f3>] kill_anon_super+0x1d/0x7e
 [<ffffffffa00d0be1>] nfs4_kill_super+0x60/0xb6 [nfs]
 [<ffffffff81161c17>] deactivate_locked_super+0x34/0x83
 [<ffffffff811629ff>] deactivate_super+0x6f/0x7b
 [<ffffffff81186261>] mntput_no_expire+0x18d/0x199
 [<ffffffff811862a8>] mntput+0x3b/0x44
 [<ffffffff81186d87>] release_mounts+0xa2/0xbf
 [<ffffffff811876af>] sys_umount+0x47a/0x4ba
 [<ffffffff8109e1ca>] ? trace_hardirqs_on_caller+0x1fd/0x22f
 [<ffffffff816ea86b>] system_call_fastpath+0x16/0x1b

as do_umount() is inlined.  However, you can see release_mounts() in there.

Note also that it may be necessary to have multiple CPU cores to be able to
trigger this bug.
Tested-by: NJeff Layton <jlayton@redhat.com>
Tested-by: NIan Kent <raven@themaw.net>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      8aef1884
    • T
      fix wrong iput on d_inode introduced by e6bc45d6 · 50338b88
      由 Török Edwin 提交于 
      Git bisection shows that commit e6bc45d6 causes
BUG_ONs under high I/O load:

kernel BUG at fs/inode.c:1368!
[ 2862.501007] Call Trace:
[ 2862.501007]  [<ffffffff811691d8>] d_kill+0xf8/0x140
[ 2862.501007]  [<ffffffff81169c19>] dput+0xc9/0x190
[ 2862.501007]  [<ffffffff8115577f>] fput+0x15f/0x210
[ 2862.501007]  [<ffffffff81152171>] filp_close+0x61/0x90
[ 2862.501007]  [<ffffffff81152251>] sys_close+0xb1/0x110
[ 2862.501007]  [<ffffffff814c14fb>] system_call_fastpath+0x16/0x1b

A reliable way to reproduce this bug is:
Login to KDE, run 'rsnapshot sync', and apt-get install openjdk-6-jdk,
and apt-get remove openjdk-6-jdk.

The buggy part of the patch is this:
	struct inode *inode = NULL;
.....
-               if (nd.last.name[nd.last.len])
-                       goto slashes;
                inode = dentry->d_inode;
-               if (inode)
-                       ihold(inode);
+               if (nd.last.name[nd.last.len] || !inode)
+                       goto slashes;
+               ihold(inode)
...
	if (inode)
		iput(inode);	/* truncate the inode here */

If nd.last.name[nd.last.len] is nonzero (and thus goto slashes branch is taken),
and dentry->d_inode is non-NULL, then this code now does an additional iput on
the inode, which is wrong.

Fix this by only setting the inode variable if nd.last.name[nd.last.len] is 0.

Reference: https://lkml.org/lkml/2011/6/15/50Reported-by: NNorbert Preining <preining@logic.at>
Reported-by: NTörök Edwin <edwintorok@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NTörök Edwin <edwintorok@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      50338b88
    • L
      mm: get rid of the most spurious find_vma_prev() users · 9be34c9d
      由 Linus Torvalds 提交于 
      We have some users of this function that date back to before the vma
list was doubly linked, and just are silly.  These days, you can find
the previous vma by just following the vma->vm_prev pointer.

In some cases you don't need any find_vma() lookup at all, and in other
cases you're better off with the regular "find_vma()" that uses the vma
cache front-end lookup.

Some "find_vma_prev()" users are still valid, though.  For example, in
the case of a stack that grows up, it can be the case that we don't find
any 'vma' at all (because we're looking up an address that is past the
last vma), and that the stack that we want to grow is the 'prev' vma.

But that kind of special case aside, we generally should prefer to use
'find_vma()'.

Noticed due to a totally unrelated POWER memory corruption bug that just
happened to hit in 'find_vma_prev()' and made me go "Hmm - why are we
using that function here?".
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9be34c9d
    • C
      drivers/gpu/drm: use printk_ratelimited instead of printk_ratelimit · cafe8d84
      由 Christian Dietrich 提交于 
      Since printk_ratelimit() shouldn't be used anymore (see comment in
include/linux/printk.h), replace it with printk_ratelimited.
Signed-off-by: NChristian Dietrich <christian.dietrich@informatik.uni-erlangen.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>
      cafe8d84
    • D
      drm/radeon: workaround a hw bug on some radeon chipsets with all-0 EDIDs. · 4a9a8b71
      由 Dave Airlie 提交于 
      Some RS690 chipsets seem to end up with floating connectors, either
a DVI connector isn't actually populated, or an add-in HDMI card
is available but not installed. In this case we seem to get a NULL byte
response for each byte of the i2c transaction, so we detect this
case and if we see it we don't do anymore DDC transactions on this
connector.

I've tested this on my RS690 without the HDMI card installed and
it seems to work fine.
Signed-off-by: NDave Airlie <airlied@redhat.com>
Reviewed-by: NAlex Deucher <alexdeucher@gmail.com>
      4a9a8b71
    • D
      drm: make debug levels match in edid failure code. · f49dadb8
      由 Dave Airlie 提交于 
      this puts the header and followup at the same loglevel as the
hex dump code.
Signed-off-by: NDave Airlie <airlied@redhat.com>
Reviewed-by: NAlex Deucher <alexdeucher@gmail.com>
      f49dadb8
    • A
      drm/radeon/kms: clear wb memory by default · e6ba7599
      由 Alex Deucher 提交于 
      Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
      e6ba7599
    • A
      drm/radeon/kms: be more pedantic about the g5 quirk (v2) · 7c88d2b8
      由 Alex Deucher 提交于 
      I don't think Apple offered any other cards for
this mac, so I doubt this will be an issue, but just
to be on the safe side, check the pci ids as well.

v2: fix spelling in commit message
Reviewed-by: NMichel Dänzer <michel@daenzer.net>
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Cc: Joachim Henke <j-o@users.sourceforge.net>
Cc: Michel Dänzer <michel@daenzer.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>
      7c88d2b8
    • A
      drm/radeon/kms: signed fix for evergreen thermal · 1c88d74f
      由 Alex Deucher 提交于 
      temperature is signed.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
      1c88d74f
    • W
      drm: populate irq_by_busid-member for pci · 45e97ab6
      由 Wolfram Sang 提交于 
      Commit 8410ea (drm: rework PCI/platform driver interface) implemented
drm_pci_irq_by_busid() but forgot to make it available in the
drm_pci_bus-struct.

This caused a freeze on my Radeon9600-equipped laptop when executing glxgears.
Thanks to Michel for noticing the flaw.

[airlied: made function static also]
Reported-by: NMichel Dänzer <daenzer@vmware.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>
      45e97ab6
    • K
      sh: sh7724: Add USBHS DMAEngine support · 261a9af6
      由 Kuninori Morimoto 提交于 
      Signed-off-by: NKuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      261a9af6
    • K
      sh: ecovec: Add renesas_usbhs support · fb2e7394
      由 Kuninori Morimoto 提交于 
      Signed-off-by: NKuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      fb2e7394
    • L
      Merge branch 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm · 19a1166f
      由 Linus Torvalds 提交于 
      * 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
  ARM: footbridge: fix clock event support
  ARM: footbridge: fix debug macros
  ARM: initrd: disable initrds outside of memory
  ARM: extend Code: line by one 16-bit quantity for Thumb instructions
  ARM: 6955/1: cmpxchg syscall should data abort if page not write
  ARM: 6954/1: zImage: fix Thumb2 breakage
  ARM: 6953/1: DT: don't try to access physical address zero
  ARM: 6949/2: mach-u300: fix compilaton warning in IO accessors
  Revert "ARM: 6944/1: mm: allow ASID 0 to be allocated to tasks"
  Revert "ARM: 6943/1: mm: use TTBR1 instead of reserved context ID"
  davinci: make PCM platform devices static
  arm: davinci: Fix fallout from generic irq chip conversion
  ARM: 6894/1: mmci: trigger card detect IRQs on falling and rising edges
  ARM: 6952/1: fix lockdep warning of "unannotated irqs-off"
  ARM: 6951/1: include .bss in memory layout information
  ARM: 6948/1: Fix .size directives for __arm{7,9}tdmi_proc_info
  ARM: 6947/2: mach-u300: fix compilation error in timer
  ARM: 6946/1: vexpress: move v2m clock init to init_early
  ARM: mx51/sdma: Check the chip revision in run-time
  arm: mxs: include asm/processor.h for cpu_relax()
      19a1166f
    • L
      Revert "fs/exec.c: use BUILD_BUG_ON for VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP" · 13fca640
      由 Linus Torvalds 提交于 
      This reverts commit 7f81c889.

It turns out that it's not actually a build-time check on x86-64 UML,
which does some seriously crazy stuff with VM_STACK_FLAGS.

The VM_STACK_FLAGS define depends on the arch-supplied
VM_STACK_DEFAULT_FLAGS value, and on x86-64 UML we have

  arch/um/sys-x86_64/shared/sysdep/vm-flags.h:

	#define VM_STACK_DEFAULT_FLAGS \
		(test_thread_flag(TIF_IA32) ? vm_stack_flags32 : vm_stack_flags)

	#define VM_STACK_DEFAULT_FLAGS vm_stack_flags

(yes, seriously: two different #define's for that thing, with the first
one being inside an "#ifdef TIF_IA32")

It's possible that it is UML that should just be fixed in this area, but
for now let's just undo the (very small) optimization.
Reported-by: NRandy Dunlap <randy.dunlap@oracle.com>
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      13fca640