diff options
author | Nathaniel W. Turner <nate@houseofnate.net> | 2009-11-16 19:51:48 +0000 |
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committer | Alex Elder <aelder@sgi.com> | 2009-11-17 10:26:49 -0600 |
commit | 6c06f072c2d797ddbb2270363de97c53ebbe0385 (patch) | |
tree | 03654fd6af68f5ba0004f9e7c2b6945504de53f3 /fs/sysv | |
parent | 8ec6dba2581754e375be66f7bedd708d856d8b30 (diff) |
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 <nate@houseofnate.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Diffstat (limited to 'fs/sysv')
0 files changed, 0 insertions, 0 deletions