On Tuesday, 27 of November 2007, David Chinner wrote: > On Tue, Nov 27, 2007 at 04:51:38PM +0100, Rafael J. Wysocki wrote: > > On Monday, 26 of November 2007, Rafael J. Wysocki wrote: > > > On Monday, 26 of November 2007, David Chinner wrote: > > > > Now there's a message that I haven't seen in about 3 years. > > > > > > > > It indicates that the linux inode connected to the xfs_inode is not > > > > the correct one. i.e. that the linux inode cache is out of step with > > > > the XFS inode cache. > > > > > > > > Basically, that is not supposed to happen. I suspect that the way > > > > threads are frozen is resulting in an inode lookup racing with > > > > a reclaim. The reclaim thread gets stopped after any use threads, > > > > and so we could have the situation that a process blocked in lookup > > > > has the XFS inode reclaimed and reused before it gets unblocked. > > > > > > > > The question is why is it happening now when none of that code in > > > > XFS has changed? > > > > > > > > Rafael, when are threads frozen? Only when they schedule or call > > > > try_to_freeze()? > > > > > > Kernel threads freeze only when they call try_to_freeze(). User space > > > tasks > > > freeze while executing the signals handling code. > > > > > > > Did the freezer mechanism change in 2.6.23 (this is on 2.6.23.1)? > > > > > > Yes. Kernel threads are not sent fake signals by the freezer any more. > > > > Ah, sorry, this change has been merged after 2.6.23. However, before 2.6.23 > > we had another important change that caused all kernel threads to have > > PF_NOFREEZE set by default, unless they call set_freezable() explicitly. > > So try_to_freeze() will never freeze a thread if it has not been > set_freezable()? And xfsbufd will never be frozen?
No, it won't. I must have overlooked it, probably because it calls refrigerator() directly and not try_to_freeze() ... I think something like the appended patch will help, then. Greetings, Rafael --- Fix breakage caused by commit 831441862956fffa17b9801db37e6ea1650b0f69 that did not introduce the necessary call to set_freezable() in xfs/linux-2.6/xfs_buf.c . Signed-off-by: Rafael J. Wysocki <[EMAIL PROTECTED]> --- fs/xfs/linux-2.6/xfs_buf.c | 2 ++ 1 file changed, 2 insertions(+) Index: linux-2.6/fs/xfs/linux-2.6/xfs_buf.c =================================================================== --- linux-2.6.orig/fs/xfs/linux-2.6/xfs_buf.c +++ linux-2.6/fs/xfs/linux-2.6/xfs_buf.c @@ -1750,6 +1750,8 @@ xfsbufd( current->flags |= PF_MEMALLOC; + set_freezable(); + do { if (unlikely(freezing(current))) { set_bit(XBT_FORCE_SLEEP, &target->bt_flags); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/