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  1. 21 Jul, 2012 24 commits
  3. 11 Jul, 2012 9 commits
  5. 07 Jul, 2012 3 commits
    • Tejun Heo's avatar
      cgroup: fix cgroup hierarchy umount race · 5db9a4d9
      Tejun Heo authored 
      48ddbe19 "cgroup: make css->refcnt clearing on cgroup removal
optional" allowed a css to linger after the associated cgroup is
removed.  As a css holds a reference on the cgroup's dentry, it means
that cgroup dentries may linger for a while.

Destroying a superblock which has dentries with positive refcnts is a
critical bug and triggers BUG() in vfs code.  As each cgroup dentry
holds an s_active reference, any lingering cgroup has both its dentry
and the superblock pinned and thus preventing premature release of
superblock.

Unfortunately, after 48ddbe19, there's a small window while
releasing a cgroup which is directly under the root of the hierarchy.
When a cgroup directory is released, vfs layer first deletes the
corresponding dentry and then invokes dput() on the parent, which may
recurse further, so when a cgroup directly below root cgroup is
released, the cgroup is first destroyed - which releases the s_active
it was holding - and then the dentry for the root cgroup is dput().

This creates a window where the root dentry's refcnt isn't zero but
superblock's s_active is.  If umount happens before or during this
window, vfs will see the root dentry with non-zero refcnt and trigger
BUG().

Before 48ddbe19, this problem didn't exist because the last dentry
reference was guaranteed to be put synchronously from rmdir(2)
invocation which holds s_active around the whole process.

Fix it by holding an extra superblock->s_active reference across
dput() from css release, which is the dput() path added by 48ddbe19
and the only one which doesn't hold an extra s_active ref across the
final cgroup dput().
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
LKML-Reference: <4FEEA5CB.8070809@huawei.com>
Reported-by: default avatarshyju pv <shyju.pv@huawei.com>
Tested-by: default avatarshyju pv <shyju.pv@huawei.com>
Cc: Sasha Levin <levinsasha928@gmail.com>
Acked-by: default avatarLi Zefan <lizefan@huawei.com>
      5db9a4d9
    • Tejun Heo's avatar
      Revert "cgroup: superblock can't be released with active dentries" · 7db5b3ca
      Tejun Heo authored 
      This reverts commit fa980ca8.  The
commit was an attempt to fix a race condition where a cgroup hierarchy
may be unmounted with positive dentry reference on root cgroup.  While
the commit made the race condition slightly more difficult to trigger,
the race was still there and could be reliably triggered using a
different test case.

Revert the incorrect fix.  The next commit will describe the race and
fix it correctly.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
LKML-Reference: <4FEEA5CB.8070809@huawei.com>
Reported-by: default avatarshyju pv <shyju.pv@huawei.com>
Cc: Sasha Levin <levinsasha928@gmail.com>
Acked-by: default avatarLi Zefan <lizefan@huawei.com>
      7db5b3ca
    • Linus Torvalds's avatar
      Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm · cd6407fe
      Linus Torvalds authored 
      Pull ARM fixes from Russell King:
 "Last merge window, we had some updates from Al cleaning up the signal
  restart handling.  These have caused some problems on ARM, and while
  Al has some fixes, we have some concerns with Al's patches but we've
  been unsuccesful with discussing this.

  We have got to the point where we need to do something, and we've
  decided that the best solution is to revert the appropriate commits
  until Al is able to reply to us.

  Also included here are four patches to fix warnings that I've noticed
  in my build system, and one fix for kprobes test code."

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: fix warning caused by wrongly typed arm_dma_limit
  ARM: fix warnings about atomic64_read
  ARM: 7440/1: kprobes: only test 'sub pc, pc, #1b-2b+8-2' on ARMv6
  ARM: 7441/1: perf: return -EOPNOTSUPP if requested mode exclusion is unavailable
  ARM: 7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK"
  ARM: 7442/1: Revert "remove unused restart trampoline"
  ARM: fix set_domain() macro
  ARM: fix mach-versatile/pci.c warning
      cd6407fe
  7. 06 Jul, 2012 4 commits
    • Linus Torvalds's avatar
      Merge tag 'ecryptfs-3.5-rc6-fixes' of... · 26c439d4
      Linus Torvalds authored 
      Merge tag 'ecryptfs-3.5-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs

Pull eCryptfs fixes from Tyler Hicks:
 "Fixes an incorrect access mode check when preparing to open a file in
  the lower filesystem.  This isn't an urgent fix, but it is simple and
  the check was obviously incorrect.

  Also fixes a couple important bugs in the eCryptfs miscdev interface.
  These changes are low risk due to the small number of users that use
  the miscdev interface.  I was able to keep the changes minimal and I
  have some cleaner, more complete changes queued up for the next merge
  window that will build on these patches."

* tag 'ecryptfs-3.5-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  eCryptfs: Gracefully refuse miscdev file ops on inherited/passed files
  eCryptfs: Fix lockdep warning in miscdev operations
  eCryptfs: Properly check for O_RDONLY flag before doing privileged open
      26c439d4
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending · c8912f2b
      Linus Torvalds authored 
      Pull target fixes from Nicholas Bellinger:
 "Two minor target fixes.  There is really nothing exciting and/or
  controversial this time around.

  There's one fix from MDR for a RCU debug warning message within tcm_fc
  code (CC'ed to stable), and a small AC fix for qla_target.c based upon
  a recent Coverity static report.

  Also, there is one other outstanding virtio-scsi LUN scanning bugfix
  that has been uncovered with the in-flight tcm_vhost driver over the
  last days, and that needs to make it into 3.5 final too.  This patch
  has been posted to linux-scsi again here:

    http://marc.info/?l=linux-scsi&m=134160609212542&w=2

  and I've asked James to include it in his next PULL request."

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  qla2xxx: print the right array elements in qlt_async_event
  tcm_fc: Resolve suspicious RCU usage warnings
      c8912f2b
    • Tyler Hicks's avatar
      eCryptfs: Gracefully refuse miscdev file ops on inherited/passed files · 8dc67805
      Tyler Hicks authored 
      File operations on /dev/ecryptfs would BUG() when the operations were
performed by processes other than the process that originally opened the
file. This could happen with open files inherited after fork() or file
descriptors passed through IPC mechanisms. Rather than calling BUG(), an
error code can be safely returned in most situations.

In ecryptfs_miscdev_release(), eCryptfs still needs to handle the
release even if the last file reference is being held by a process that
didn't originally open the file. ecryptfs_find_daemon_by_euid() will not
be successful, so a pointer to the daemon is stored in the file's
private_data. The private_data pointer is initialized when the miscdev
file is opened and only used when the file is released.

https://launchpad.net/bugs/994247Signed-off-by: default avatarTyler Hicks <tyhicks@canonical.com>
Reported-by: default avatarSasha Levin <levinsasha928@gmail.com>
Tested-by: default avatarSasha Levin <levinsasha928@gmail.com>
      8dc67805
    • Alan Cox's avatar
      qla2xxx: print the right array elements in qlt_async_event · 4f1d0f19
      Alan Cox authored 
      Based upon Alan's patch from Coverity scan id 793583, these debug
messages in qlt_async_event() should be starting from byte 0, which is
always the Asynchronous Event Status Code from the parent switch statement.

Also, rename reason_code -> login_code following the language used in
2500 FW spec for Port Database Changed (0x8014) -> Port Database Changed
Event Mailbox Register for mailbox[2].
Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Cc: Chad Dupuis <chad.dupuis@qlogic.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      4f1d0f19
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