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From: Christoph Hellwig <hch@infradead.org>
To: david@fromorbit.com
Cc: xfs@oss.sgi.com
Subject: protecting per-ag access in the sync path
Date: Tue, 24 Nov 2009 12:04:55 -0500	[thread overview]
Message-ID: <20091124170455.GA9021@infradead.org> (raw)

Since Linux 2.6.29 we use the perag structures a lot in the sync path,
but we're not actually protecting against the re-allocation in growfs.

I've recently received a new, fast SSD which allows me to hit those
races.  With it 104 reproducibly crashes the system, hitting the slab
redzoning for the old per-ag structure.  I experimentally put
synchronization using m_peraglock into xfs_inode_ag_walk which fixes the
issue at the cost of lock order reversals between the i_lock and the
m_peraglock in various places.

Any better idea how to protect the new sync path against growfs?

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             reply	other threads:[~2009-11-24 17:04 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-11-24 17:04 Christoph Hellwig [this message]
2009-11-25  0:05 ` protecting per-ag access in the sync path Dave Chinner

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