From: Nathaniel W. Turner Date: Mon, 16 Nov 2009 19:51:48 +0000 (+0000) Subject: xfs: copy li_lsn before dropping AIL lock X-Git-Tag: v2.6.32-rc8~23^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6c06f072c2d797ddbb2270363de97c53ebbe0385;p=pandora-kernel.git xfs: copy li_lsn before dropping AIL lock Access to log items on the AIL is generally protected by m_ail_lock; this is particularly needed when we're getting or setting the 64-bit li_lsn on a 32-bit platform. This patch fixes a couple places where we were accessing the log item after dropping the AIL lock on 32-bit machines. This can result in a partially-zeroed log->l_tail_lsn if xfs_trans_ail_delete is racing with xfs_trans_ail_update, and in at least some cases, this can leave the l_tail_lsn with a zero cycle number, which means xlog_space_left will think the log is full (unless CONFIG_XFS_DEBUG is set, in which case we'll trip an ASSERT), leading to processes stuck forever in xlog_grant_log_space. Thanks to Adrian VanderSpek for first spotting the race potential and to Dave Chinner for debug assistance. Signed-off-by: Nathaniel W. Turner Reviewed-by: Christoph Hellwig Signed-off-by: Alex Elder --- Reading git-diff-tree failed