From 2a64f80ee3ab47dc0114e077ea27903c97882138 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 23 Nov 2016 13:47:57 +0100 Subject: [PATCH] ocfs2: Protect periodic quota syncing with s_umount semaphore New quota locking rules will require s_umount semaphore for all quota scanning functions. Add is for periodic quota syncing. Tested-by: Eric Ren Signed-off-by: Jan Kara --- fs/ocfs2/quota_global.c | 10 +++++++++- fs/ocfs2/super.c | 1 - 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c index 87e577a49b0d..cec495a921e3 100644 --- a/fs/ocfs2/quota_global.c +++ b/fs/ocfs2/quota_global.c @@ -634,7 +634,15 @@ static void qsync_work_fn(struct work_struct *work) dqi_sync_work.work); struct super_block *sb = oinfo->dqi_gqinode->i_sb; - dquot_scan_active(sb, ocfs2_sync_dquot_helper, oinfo->dqi_type); + /* + * We have to be careful here not to deadlock on s_umount as umount + * disabling quotas may be in progress and it waits for this work to + * complete. If trylock fails, we'll do the sync next time... + */ + if (down_read_trylock(&sb->s_umount)) { + dquot_scan_active(sb, ocfs2_sync_dquot_helper, oinfo->dqi_type); + up_read(&sb->s_umount); + } schedule_delayed_work(&oinfo->dqi_sync_work, msecs_to_jiffies(oinfo->dqi_syncms)); } diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index f56fe39fab04..5b9c0dfdb541 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -985,7 +985,6 @@ static void ocfs2_disable_quotas(struct ocfs2_super *osb) for (type = 0; type < OCFS2_MAXQUOTAS; type++) { if (!sb_has_quota_loaded(sb, type)) continue; - /* Cancel periodic syncing before we grab dqonoff_mutex */ oinfo = sb_dqinfo(sb, type)->dqi_priv; cancel_delayed_work_sync(&oinfo->dqi_sync_work); inode = igrab(sb->s_dquot.files[type]); -- 2.30.2