From 10ee25268e1f8475905e1deb85bb83627dca561e Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 21 Jun 2018 23:26:55 -0700 Subject: [PATCH] xfs: allow empty transactions while frozen In commit e89c041338ed6ef ("xfs: implement the GETFSMAP ioctl") we created the ability to obtain empty transactions. These transactions have no log or block reservations and therefore can't modify anything. Since they're also NO_WRITECOUNT they can run while the fs is frozen, so we don't need to WARN_ON about that usage. Signed-off-by: Darrick J. Wong Reviewed-by: Allison Henderson Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_trans.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index e040af1..524f543 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -258,7 +258,12 @@ xfs_trans_alloc( if (!(flags & XFS_TRANS_NO_WRITECOUNT)) sb_start_intwrite(mp->m_super); - WARN_ON(mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE); + /* + * Zero-reservation ("empty") transactions can't modify anything, so + * they're allowed to run while we're frozen. + */ + WARN_ON(resp->tr_logres > 0 && + mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE); atomic_inc(&mp->m_active_trans); tp = kmem_zone_zalloc(xfs_trans_zone, -- 2.7.4