>From 276d5ecac71d9e6ec6ac970e594f5a49450d07e2 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 6 Mar 2012 11:39:48 +0100 Subject: [PATCH v2] xfs: Fix oops on IO error during xlog_recover_process_iunlinks() When an IO error happens during inode deletion run from xlog_recover_process_iunlinks() filesystem gets shutdown. Thus any subsequent attempt to read buffers fails. Code in xlog_recover_process_iunlinks() does not count with the fact that read of a buffer which was read a while ago can really fail which results in the oops on agi = XFS_BUF_TO_AGI(agibp); Fix the problem by cleaning up the buffer handling in xlog_recover_process_iunlinks(). We release buffer lock but keep buffer reference to AG buffer. That is enough for buffer to not go away under us and we don't have to call xfs_read_agi() all the time. CC: stable@xxxxxxxxxx Signed-off-by: Jan Kara --- fs/xfs/xfs_log_recover.c | 34 ++++++++++++---------------------- 1 files changed, 12 insertions(+), 22 deletions(-) diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 0ed9ee7..0827644 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -3161,37 +3161,27 @@ xlog_recover_process_iunlinks( */ continue; } + /* + * Take an extra reference to the buffer and then release it + * to drop the lock so that it can be acquired in the normal + * course of the transaction to truncate and free each + * inode. Because we are not racing with anyone else here + * for the AGI buffer, we don't even need to hold it locked + * to read the initial unlinked bucket entries out of the + * buffer. + */ agi = XFS_BUF_TO_AGI(agibp); + xfs_buf_hold(agibp); + xfs_buf_relse(agibp); for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++) { agino = be32_to_cpu(agi->agi_unlinked[bucket]); while (agino != NULLAGINO) { - /* - * Release the agi buffer so that it can - * be acquired in the normal course of the - * transaction to truncate and free the inode. - */ - xfs_buf_relse(agibp); - agino = xlog_recover_process_one_iunlink(mp, agno, agino, bucket); - - /* - * Reacquire the agibuffer and continue around - * the loop. This should never fail as we know - * the buffer was good earlier on. - */ - error = xfs_read_agi(mp, NULL, agno, &agibp); - ASSERT(error == 0); - agi = XFS_BUF_TO_AGI(agibp); } } - - /* - * Release the buffer for the current agi so we can - * go on to the next one. - */ - xfs_buf_relse(agibp); + xfs_buf_rele(agibp); } mp->m_dmevmask = mp_dmevmask; -- 1.7.1