From mboxrd@z Thu Jan  1 00:00:00 1970
From: hooanon05@yahoo.co.jp
Subject: Re: [PATCH] fsstack: fsstack_copy_inode_size locking
Date: Mon, 30 Jun 2008 13:31:57 +0900
Message-ID: <8725.1214800317@jrobl>
References: <Pine.LNX.4.64.0806290101160.20280@blonde.site>
Cc: Erez Zadok <ezk@cs.sunysb.edu>,
	Andrew Morton <akpm@linux-foundation.org>, mhalcrow@us.ibm.com,
	hch@infradead.org, viro@zeniv.linux.org.uk,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
To: Hugh Dickins <hugh@veritas.com>
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Hugh Dickins:
> LTP's iogen01 doio tests used to hang nicely on 32-bit SMP when /tmp was a
> unionfs mount of a tmpfs, i_size_read spinning forever, waiting for a lost
> seqcount update: fixed by taking i_lock around i_size_write when 32-bit SMP.

I don't know why dst->i_lock is affected by src->i_size_seqcount.
Do you mean that your test issued write(2) to the lower/actual file so
frequently that i_size_read() in unionfs always failed?

Is your test
iogen01 export LTPROOT; rwtest -N iogen01 -i 120s -s read,write -Da -Dv -n 2 500b:doio.f1.$$ 1000b:doio.f2.$$
line in runtest/fs?


Junjiro Okajima