From mboxrd@z Thu Jan 1 00:00:00 1970 From: Abhi Das Date: Tue, 30 Apr 2019 12:48:30 -0500 Subject: [Cluster-devel] [PATCH] gfs2: fix race between gfs2_freeze_func and unmount Message-ID: <20190430174830.18057-1-adas@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit gfs2_unfreee() doesn't wait for gfs2_freeze_func() to complete. If a umount is issued right after unfreeze, it could result in an inconsistent filesystem because some journal data (statfs update) wasn't written out. This patch causes gfs2_unfreeze() to wait for gfs2_freeze_func() to complete before returning to the user. Signed-off-by: Abhi Das --- fs/gfs2/incore.h | 1 + fs/gfs2/super.c | 8 +++++--- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h index 78c8e761b321..b15755068593 100644 --- a/fs/gfs2/incore.h +++ b/fs/gfs2/incore.h @@ -621,6 +621,7 @@ enum { SDF_SKIP_DLM_UNLOCK = 8, SDF_FORCE_AIL_FLUSH = 9, SDF_AIL1_IO_ERROR = 10, + SDF_FS_FROZEN = 11, }; enum gfs2_freeze_state { diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c index a6a325b2a78b..a81d7a5afe39 100644 --- a/fs/gfs2/super.c +++ b/fs/gfs2/super.c @@ -973,8 +973,7 @@ void gfs2_freeze_func(struct work_struct *work) if (error) { printk(KERN_INFO "GFS2: couldn't get freeze lock : %d\n", error); gfs2_assert_withdraw(sdp, 0); - } - else { + } else { atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN); error = thaw_super(sb); if (error) { @@ -987,6 +986,8 @@ void gfs2_freeze_func(struct work_struct *work) gfs2_glock_dq_uninit(&freeze_gh); } deactivate_super(sb); + clear_bit(SDF_FS_FROZEN, &sdp->sd_flags); + wake_up_bit(&sdp->sd_flags, SDF_FS_FROZEN); return; } @@ -1029,6 +1030,7 @@ static int gfs2_freeze(struct super_block *sb) msleep(1000); } error = 0; + set_bit(SDF_FS_FROZEN, &sdp->sd_flags); out: mutex_unlock(&sdp->sd_freeze_mutex); return error; @@ -1053,7 +1055,7 @@ static int gfs2_unfreeze(struct super_block *sb) gfs2_glock_dq_uninit(&sdp->sd_freeze_gh); mutex_unlock(&sdp->sd_freeze_mutex); - return 0; + return wait_on_bit(&sdp->sd_flags, SDF_FS_FROZEN, TASK_INTERRUPTIBLE); } /** -- 2.20.1