[Bug 15805] New: reiserfs locking

[Bug 15805] New: reiserfs locking

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=15805

           Summary: reiserfs locking
           Product: File System
           Version: 2.5
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: ReiserFS
        AssignedTo: reiserfs-devel@vger.kernel.org
        ReportedBy: maciej.rutecki@gmail.com
                CC: rjw@sisk.pl, maciej.rutecki@gmail.com,
                    a.beregalov@gmail.com
        Regression: Yes


Subject    : reiserfs locking
Submitter  : Alexander Beregalov <a.beregalov@gmail.com>
Date       : 2010-04-15 21:02
Message-ID : t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com
References : http://marc.info/?l=linux-kernel&m=127136535323933&w=2

This entry is being used for tracking a regression from 2.6.32.  Please don't
close it until the problem is fixed in the mainline.

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[Bug 15805] reiserfs locking

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=15805


Maciej Rutecki <maciej.rutecki@gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|                            |15310




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[Bug 15805] reiserfs locking

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=15805


Rafael J. Wysocki <rjw@sisk.pl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Kernel Version|                            |2.6.34-rc3




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[Bug 15805] reiserfs locking

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=15805





--- Comment #1 from Rafael J. Wysocki <rjw@sisk.pl>  2010-06-13 12:16:11 ---
Handled-By : Frederic Weisbecker <fweisbec@gmail.com>

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[Bug 15805] reiserfs locking

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=15805





--- Comment #2 from Rafael J. Wysocki <rjw@sisk.pl>  2010-07-10 13:02:31 ---
On Saturday, July 10, 2010, Frederic Weisbecker wrote:
> On Sat, Jul 10, 2010 at 02:33:24AM +0200, Rafael J. Wysocki wrote:
> > This message has been generated automatically as a part of a report
> > of regressions introduced between 2.6.33 and 2.6.34.
> > 
> > The following bug entry is on the current list of known regressions
> > introduced between 2.6.33 and 2.6.34.  Please verify if it still should
> > be listed and let the tracking team know (either way).
> > 
> > 
> > Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> > Subject		: reiserfs locking
> > Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
> > Date		: 2010-04-15 21:02 (86 days old)
> > Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
> > References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
> > Handled-By	: Frederic Weisbecker <fweisbec@gmail.com>
> 
> 
> It's a duplicate of 16334. Or rather 16334 is a duplicate of this
> but the discussion about the issue was more developped in 16334.
> 
> Anyway this is not a regression (at least not recent) and the fix
> from Al is in the vfs tree in the for-next branch on commit
> 6c2bdaf089a3876226893fab00dd83596c465ad2
> "Fix reiserfs_file_release()"

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[Bug 15805] reiserfs locking

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=15805


Rafael J. Wysocki <rjw@sisk.pl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |DUPLICATE




--- Comment #3 from Rafael J. Wysocki <rjw@sisk.pl>  2010-07-10 13:02:55 ---


*** This bug has been marked as a duplicate of bug 16334 ***

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[Bug 15805] reiserfs locking

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=15805


Rafael J. Wysocki <rjw@sisk.pl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED




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Re: [Bug #15805] reiserfs locking

[Linus Torvalds]

On Sat, Jul 10, 2010 at 12:06 AM, Ingo Molnar <mingo@elte.hu> wrote:
>
> Since it's a reproducible deadlock maybe the fix should go upstream faster
> than v2.6.36?

As far as I know, it's only a lockdep warning, not an actual deadlock.
And it's in a class of lockdep warnings that we've had for a long
time, and has never actually triggered as a read deadlock afaik.

I also don't think it's a new warning - or at least I don't see why it
would have started triggering after 2.6.34.

My preferred fix in many ways would be to make the locking in the VM
layer less incestuous. For example, we could fairly easily move the
final

  if (vma->vm_file)
    fput(vma->vm_file);

outside the actual mmap_sem lock (well, "fairly easily" here means
keeping the list of free'd vmas around for longer, probably in the
task_struct thing, and then replacing all the
"up_write(&mm->mmap_sem)" things with a "unlock_mm(mm)" looking
something like

  static void unlock_mm(struct mm_struct *mm)
  {
    struct vm_area_struct *vma_list = current->vma_to_free;
    if (vma_list)
      current->vma_to_free = NULL;
    up_write(&mm->mmap_sem);
    while (vma_list) {
      struct vm_area_struct *vma = vma_list;
      vma_list = vma_list->next;
      fput(vma_list->vm_file);
      kmem_cache_free(vm_area_cachep, vma);
    }
  }

which would fairly trivially delay the actual 'fput()' to after we
hold no locks.

I dunno if it's really worth it, but it doesn't look all that
complicated, and it would avoid at least _some_ lock dependencies.

                     Linus

                     Linus

Re: [Bug #15805] reiserfs locking

[Linus Torvalds]

On Sat, Jul 10, 2010 at 12:06 AM, Ingo Molnar <mingo-X9Un+BFzKDI@public.gmane.org> wrote:
>
> Since it's a reproducible deadlock maybe the fix should go upstream faster
> than v2.6.36?

As far as I know, it's only a lockdep warning, not an actual deadlock.
And it's in a class of lockdep warnings that we've had for a long
time, and has never actually triggered as a read deadlock afaik.

I also don't think it's a new warning - or at least I don't see why it
would have started triggering after 2.6.34.

My preferred fix in many ways would be to make the locking in the VM
layer less incestuous. For example, we could fairly easily move the
final

  if (vma->vm_file)
    fput(vma->vm_file);

outside the actual mmap_sem lock (well, "fairly easily" here means
keeping the list of free'd vmas around for longer, probably in the
task_struct thing, and then replacing all the
"up_write(&mm->mmap_sem)" things with a "unlock_mm(mm)" looking
something like

  static void unlock_mm(struct mm_struct *mm)
  {
    struct vm_area_struct *vma_list = current->vma_to_free;
    if (vma_list)
      current->vma_to_free = NULL;
    up_write(&mm->mmap_sem);
    while (vma_list) {
      struct vm_area_struct *vma = vma_list;
      vma_list = vma_list->next;
      fput(vma_list->vm_file);
      kmem_cache_free(vm_area_cachep, vma);
    }
  }

which would fairly trivially delay the actual 'fput()' to after we
hold no locks.

I dunno if it's really worth it, but it doesn't look all that
complicated, and it would avoid at least _some_ lock dependencies.

                     Linus

                     Linus

Re: [Bug #15805] reiserfs locking

[Frederic Weisbecker]

On Sat, Jul 10, 2010 at 09:06:50AM +0200, Ingo Molnar wrote:
> 
> * Frederic Weisbecker <fweisbec@gmail.com> wrote:
> 
> > On Sat, Jul 10, 2010 at 02:33:24AM +0200, Rafael J. Wysocki wrote:
> > > This message has been generated automatically as a part of a report
> > > of regressions introduced between 2.6.33 and 2.6.34.
> > > 
> > > The following bug entry is on the current list of known regressions
> > > introduced between 2.6.33 and 2.6.34.  Please verify if it still should
> > > be listed and let the tracking team know (either way).
> > > 
> > > 
> > > Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> > > Subject		: reiserfs locking
> > > Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
> > > Date		: 2010-04-15 21:02 (86 days old)
> > > Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
> > > References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
> > > Handled-By	: Frederic Weisbecker <fweisbec@gmail.com>
> > 
> > 
> > It's a duplicate of 16334. Or rather 16334 is a duplicate of this
> > but the discussion about the issue was more developped in 16334.
> > 
> > Anyway this is not a regression (at least not recent) and the fix
> > from Al is in the vfs tree in the for-next branch on commit
> > 6c2bdaf089a3876226893fab00dd83596c465ad2
> > "Fix reiserfs_file_release()"
> 
> Since it's a reproducible deadlock maybe the fix should go upstream faster 
> than v2.6.36?
> 
> Thanks,
> 
> 	Ingo


May be yeah. Although the fix is not a naive trick and it changes a sensitive
piece of code.

Don't know what Al has planned with it.

Re: [Bug #15805] reiserfs locking

[Frederic Weisbecker]

On Sat, Jul 10, 2010 at 09:06:50AM +0200, Ingo Molnar wrote:
> 
> * Frederic Weisbecker <fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> 
> > On Sat, Jul 10, 2010 at 02:33:24AM +0200, Rafael J. Wysocki wrote:
> > > This message has been generated automatically as a part of a report
> > > of regressions introduced between 2.6.33 and 2.6.34.
> > > 
> > > The following bug entry is on the current list of known regressions
> > > introduced between 2.6.33 and 2.6.34.  Please verify if it still should
> > > be listed and let the tracking team know (either way).
> > > 
> > > 
> > > Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> > > Subject		: reiserfs locking
> > > Submitter	: Alexander Beregalov <a.beregalov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > > Date		: 2010-04-15 21:02 (86 days old)
> > > Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
> > > References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
> > > Handled-By	: Frederic Weisbecker <fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > 
> > 
> > It's a duplicate of 16334. Or rather 16334 is a duplicate of this
> > but the discussion about the issue was more developped in 16334.
> > 
> > Anyway this is not a regression (at least not recent) and the fix
> > from Al is in the vfs tree in the for-next branch on commit
> > 6c2bdaf089a3876226893fab00dd83596c465ad2
> > "Fix reiserfs_file_release()"
> 
> Since it's a reproducible deadlock maybe the fix should go upstream faster 
> than v2.6.36?
> 
> Thanks,
> 
> 	Ingo


May be yeah. Although the fix is not a naive trick and it changes a sensitive
piece of code.

Don't know what Al has planned with it.

Re: [Bug #15805] reiserfs locking

[Ingo Molnar]

* Frederic Weisbecker <fweisbec@gmail.com> wrote:

> On Sat, Jul 10, 2010 at 02:33:24AM +0200, Rafael J. Wysocki wrote:
> > This message has been generated automatically as a part of a report
> > of regressions introduced between 2.6.33 and 2.6.34.
> > 
> > The following bug entry is on the current list of known regressions
> > introduced between 2.6.33 and 2.6.34.  Please verify if it still should
> > be listed and let the tracking team know (either way).
> > 
> > 
> > Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> > Subject		: reiserfs locking
> > Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
> > Date		: 2010-04-15 21:02 (86 days old)
> > Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
> > References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
> > Handled-By	: Frederic Weisbecker <fweisbec@gmail.com>
> 
> 
> It's a duplicate of 16334. Or rather 16334 is a duplicate of this
> but the discussion about the issue was more developped in 16334.
> 
> Anyway this is not a regression (at least not recent) and the fix
> from Al is in the vfs tree in the for-next branch on commit
> 6c2bdaf089a3876226893fab00dd83596c465ad2
> "Fix reiserfs_file_release()"

Since it's a reproducible deadlock maybe the fix should go upstream faster 
than v2.6.36?

Thanks,

	Ingo

Re: [Bug #15805] reiserfs locking

[Ingo Molnar]

* Frederic Weisbecker <fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

> On Sat, Jul 10, 2010 at 02:33:24AM +0200, Rafael J. Wysocki wrote:
> > This message has been generated automatically as a part of a report
> > of regressions introduced between 2.6.33 and 2.6.34.
> > 
> > The following bug entry is on the current list of known regressions
> > introduced between 2.6.33 and 2.6.34.  Please verify if it still should
> > be listed and let the tracking team know (either way).
> > 
> > 
> > Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> > Subject		: reiserfs locking
> > Submitter	: Alexander Beregalov <a.beregalov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > Date		: 2010-04-15 21:02 (86 days old)
> > Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
> > References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
> > Handled-By	: Frederic Weisbecker <fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> 
> 
> It's a duplicate of 16334. Or rather 16334 is a duplicate of this
> but the discussion about the issue was more developped in 16334.
> 
> Anyway this is not a regression (at least not recent) and the fix
> from Al is in the vfs tree in the for-next branch on commit
> 6c2bdaf089a3876226893fab00dd83596c465ad2
> "Fix reiserfs_file_release()"

Since it's a reproducible deadlock maybe the fix should go upstream faster 
than v2.6.36?

Thanks,

	Ingo

Re: [Bug #15805] reiserfs locking

[Frederic Weisbecker]

On Sat, Jul 10, 2010 at 02:33:24AM +0200, Rafael J. Wysocki wrote:
> This message has been generated automatically as a part of a report
> of regressions introduced between 2.6.33 and 2.6.34.
> 
> The following bug entry is on the current list of known regressions
> introduced between 2.6.33 and 2.6.34.  Please verify if it still should
> be listed and let the tracking team know (either way).
> 
> 
> Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> Subject		: reiserfs locking
> Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
> Date		: 2010-04-15 21:02 (86 days old)
> Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
> References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
> Handled-By	: Frederic Weisbecker <fweisbec@gmail.com>


It's a duplicate of 16334. Or rather 16334 is a duplicate of this
but the discussion about the issue was more developped in 16334.

Anyway this is not a regression (at least not recent) and the fix
from Al is in the vfs tree in the for-next branch on commit
6c2bdaf089a3876226893fab00dd83596c465ad2
"Fix reiserfs_file_release()"

Thanks.

[Bug #15805] reiserfs locking

[Rafael J. Wysocki]

This message has been generated automatically as a part of a report
of regressions introduced between 2.6.33 and 2.6.34.

The following bug entry is on the current list of known regressions
introduced between 2.6.33 and 2.6.34.  Please verify if it still should
be listed and let the tracking team know (either way).


Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
Subject		: reiserfs locking
Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
Date		: 2010-04-15 21:02 (86 days old)
Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
Handled-By	: Frederic Weisbecker <fweisbec@gmail.com>

[Bug #15805] reiserfs locking

[Rafael J. Wysocki]

This message has been generated automatically as a part of a report
of regressions introduced between 2.6.33 and 2.6.34.

The following bug entry is on the current list of known regressions
introduced between 2.6.33 and 2.6.34.  Please verify if it still should
be listed and let the tracking team know (either way).


Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
Subject		: reiserfs locking
Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
Date		: 2010-04-15 21:02 (67 days old)
Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
Handled-By	: Frederic Weisbecker <fweisbec@gmail.com>

[Bug #15805] reiserfs locking

[Rafael J. Wysocki]

This message has been generated automatically as a part of a report
of regressions introduced between 2.6.33 and 2.6.34.

The following bug entry is on the current list of known regressions
introduced between 2.6.33 and 2.6.34.  Please verify if it still should
be listed and let the tracking team know (either way).


Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
Subject		: reiserfs locking
Submitter	: Alexander Beregalov <a.beregalov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Date		: 2010-04-15 21:02 (67 days old)
Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
Handled-By	: Frederic Weisbecker <fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

[Bug #15805] reiserfs locking

[Rafael J. Wysocki]

This message has been generated automatically as a part of a report
of regressions introduced between 2.6.33 and 2.6.34.

The following bug entry is on the current list of known regressions
introduced between 2.6.33 and 2.6.34.  Please verify if it still should
be listed and let the tracking team know (either way).


Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
Subject		: reiserfs locking
Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
Date		: 2010-04-15 21:02 (60 days old)
Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2
Handled-By	: Frederic Weisbecker <fweisbec@gmail.com>

Re: [Bug #15805] reiserfs locking

[Frederic Weisbecker]

On Sun, May 09, 2010 at 11:17:36PM +0200, Rafael J. Wysocki wrote:
> This message has been generated automatically as a part of a summary report
> of recent regressions.
> 
> The following bug entry is on the current list of known regressions
> from 2.6.33.  Please verify if it still should be listed and let the tracking team
> know (either way).
> 
> 
> Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> Subject		: reiserfs locking
> Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
> Date		: 2010-04-15 21:02 (25 days old)
> Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
> References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2



I'll do some tests and see if something caused this recently.

Re: [Bug #15805] reiserfs locking

[Frederic Weisbecker]

On Sun, May 09, 2010 at 11:17:36PM +0200, Rafael J. Wysocki wrote:
> This message has been generated automatically as a part of a summary report
> of recent regressions.
> 
> The following bug entry is on the current list of known regressions
> from 2.6.33.  Please verify if it still should be listed and let the tracking team
> know (either way).
> 
> 
> Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> Subject		: reiserfs locking
> Submitter	: Alexander Beregalov <a.beregalov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Date		: 2010-04-15 21:02 (25 days old)
> Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
> References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2



I'll do some tests and see if something caused this recently.

[Bug #15805] reiserfs locking

[Rafael J. Wysocki]

This message has been generated automatically as a part of a summary report
of recent regressions.

The following bug entry is on the current list of known regressions
from 2.6.33.  Please verify if it still should be listed and let the tracking team
know (either way).


Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
Subject		: reiserfs locking
Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
Date		: 2010-04-15 21:02 (25 days old)
Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2

[Bug #15805] reiserfs locking

[Rafael J. Wysocki]

This message has been generated automatically as a part of a summary report
of recent regressions.

The following bug entry is on the current list of known regressions
from 2.6.33.  Please verify if it still should be listed and let the tracking team
know (either way).


Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
Subject		: reiserfs locking
Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
Date		: 2010-04-15 21:02 (20 days old)
Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2

Re: [Bug #15805] reiserfs locking

[Frederic Weisbecker]

On Tue, Apr 20, 2010 at 05:19:25AM +0200, Rafael J. Wysocki wrote:
> This message has been generated automatically as a part of a summary report
> of recent regressions.
> 
> The following bug entry is on the current list of known regressions
> from 2.6.33.  Please verify if it still should be listed and let the tracking team
> know (either way).
> 
> 
> Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> Subject		: reiserfs locking
> Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
> Date		: 2010-04-15 21:02 (5 days old)
> Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
> References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2


That doesn't look like related to the bkl removal.

In fact what I wonder is how we missed that before.

vfs_readdir() take the directory inode mutex
    |
    ------- copy_to_user() takes the mm->mmap_sem

sys_unmap() takes mm->mmap_sem
    |
    ------- reiserfs_file_release() takes inode mutex


The lock inversion can not happen as sys_getdents() can't be called
after the directory is closed.

I'm not sure what to do. Adding more people in Cc.

Re: [Bug #15805] reiserfs locking

[Frederic Weisbecker]

On Tue, Apr 20, 2010 at 05:19:25AM +0200, Rafael J. Wysocki wrote:
> This message has been generated automatically as a part of a summary report
> of recent regressions.
> 
> The following bug entry is on the current list of known regressions
> from 2.6.33.  Please verify if it still should be listed and let the tracking team
> know (either way).
> 
> 
> Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
> Subject		: reiserfs locking
> Submitter	: Alexander Beregalov <a.beregalov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Date		: 2010-04-15 21:02 (5 days old)
> Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
> References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2


That doesn't look like related to the bkl removal.

In fact what I wonder is how we missed that before.

vfs_readdir() take the directory inode mutex
    |
    ------- copy_to_user() takes the mm->mmap_sem

sys_unmap() takes mm->mmap_sem
    |
    ------- reiserfs_file_release() takes inode mutex


The lock inversion can not happen as sys_getdents() can't be called
after the directory is closed.

I'm not sure what to do. Adding more people in Cc.

[Bug #15805] reiserfs locking

[Rafael J. Wysocki]

This message has been generated automatically as a part of a summary report
of recent regressions.

The following bug entry is on the current list of known regressions
from 2.6.33.  Please verify if it still should be listed and let the tracking team
know (either way).


Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
Subject		: reiserfs locking
Submitter	: Alexander Beregalov <a.beregalov@gmail.com>
Date		: 2010-04-15 21:02 (5 days old)
Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb@mail.gmail.com>
References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2

[Bug #15805] reiserfs locking

[Rafael J. Wysocki]

This message has been generated automatically as a part of a summary report
of recent regressions.

The following bug entry is on the current list of known regressions
from 2.6.33.  Please verify if it still should be listed and let the tracking team
know (either way).


Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=15805
Subject		: reiserfs locking
Submitter	: Alexander Beregalov <a.beregalov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Date		: 2010-04-15 21:02 (5 days old)
Message-ID	: <t2ka4423d671004151402n7b2dc425mdc9c6bb9640d63fb-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
References	: http://marc.info/?l=linux-kernel&m=127136535323933&w=2