From 41e6362183589afd2cd51d653e277d256daab11f Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 29 Mar 2022 18:22:01 -0700 Subject: xfs: xfs_do_force_shutdown needs to block racing shutdowns When we call xfs_forced_shutdown(), the caller often expects the filesystem to be completely shut down when it returns. However, if we have racing xfs_forced_shutdown() calls, the first caller sets the mount shutdown flag then goes to shutdown the log. The second caller sees the mount shutdown flag and returns immediately - it does not wait for the log to be shut down. Unfortunately, xfs_forced_shutdown() is used in some places that expect it to completely shut down the filesystem before it returns (e.g. xfs_trans_log_inode()). As such, returning before the log has been shut down leaves us in a place where the transaction failed to complete correctly but we still call xfs_trans_commit(). This situation arises because xfs_trans_log_inode() does not return an error and instead calls xfs_force_shutdown() to ensure that the transaction being committed is aborted. Unfortunately, we have a race condition where xfs_trans_commit() needs to check xlog_is_shutdown() because it can't abort log items before the log is shut down, but it needs to use xfs_is_shutdown() because xfs_forced_shutdown() does not block waiting for the log to shut down. To fix this conundrum, first we make all calls to xfs_forced_shutdown() block until the log is also shut down. This means we can then safely use xfs_forced_shutdown() as a mechanism that ensures the currently running transaction will be aborted by xfs_trans_commit() regardless of the shutdown check it uses. Signed-off-by: Dave Chinner Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_log.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/xfs/xfs_log.c') diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 4188ed752169..678ca01047e1 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -3923,6 +3923,7 @@ xlog_force_shutdown( xlog_state_shutdown_callbacks(log); spin_unlock(&log->l_icloglock); + wake_up_var(&log->l_opstate); return log_error; } -- cgit v1.2.3