From 8866fc6fa55e31b2bce931b7963ff16641b39dc7 Mon Sep 17 00:00:00 2001 From: Ben Myers <bpm@sgi.com> Date: Fri, 25 May 2012 15:45:36 -0500 Subject: [PATCH] xfs: shutdown xfs_sync_worker before the log Revert commit 1307bbd, which uses the s_umount semaphore to provide exclusion between xfs_sync_worker and unmount, in favor of shutting down the sync worker before freeing the log in xfs_log_unmount. This is a cleaner way of resolving the race between xfs_sync_worker and unmount than using s_umount. Signed-off-by: Ben Myers <bpm@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> --- fs/xfs/xfs_log.c | 1 + fs/xfs/xfs_sync.c | 30 +++++++++++++++--------------- 2 files changed, 16 insertions(+), 15 deletions(-) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index f30d9807dc48..0e1a64f0439c 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -810,6 +810,7 @@ xfs_log_unmount_write(xfs_mount_t *mp) void xfs_log_unmount(xfs_mount_t *mp) { + cancel_delayed_work_sync(&mp->m_sync_work); xfs_trans_ail_destroy(mp); xlog_dealloc_log(mp->m_log); } diff --git a/fs/xfs/xfs_sync.c b/fs/xfs/xfs_sync.c index c9d3409c5ca3..1e9ee064dbb2 100644 --- a/fs/xfs/xfs_sync.c +++ b/fs/xfs/xfs_sync.c @@ -386,23 +386,23 @@ xfs_sync_worker( * We shouldn't write/force the log if we are in the mount/unmount * process or on a read only filesystem. The workqueue still needs to be * active in both cases, however, because it is used for inode reclaim - * during these times. Use the s_umount semaphore to provide exclusion - * with unmount. + * during these times. Use the MS_ACTIVE flag to avoid doing anything + * during mount. Doing work during unmount is avoided by calling + * cancel_delayed_work_sync on this work queue before tearing down + * the ail and the log in xfs_log_unmount. */ - if (down_read_trylock(&mp->m_super->s_umount)) { - if (!(mp->m_flags & XFS_MOUNT_RDONLY)) { - /* dgc: errors ignored here */ - if (mp->m_super->s_frozen == SB_UNFROZEN && - xfs_log_need_covered(mp)) - error = xfs_fs_log_dummy(mp); - else - xfs_log_force(mp, 0); + if (!(mp->m_super->s_flags & MS_ACTIVE) && + !(mp->m_flags & XFS_MOUNT_RDONLY)) { + /* dgc: errors ignored here */ + if (mp->m_super->s_frozen == SB_UNFROZEN && + xfs_log_need_covered(mp)) + error = xfs_fs_log_dummy(mp); + else + xfs_log_force(mp, 0); - /* start pushing all the metadata that is currently - * dirty */ - xfs_ail_push_all(mp->m_ail); - } - up_read(&mp->m_super->s_umount); + /* start pushing all the metadata that is currently + * dirty */ + xfs_ail_push_all(mp->m_ail); } /* queue us up again */