Messages in this thread | | | From | Waiman Long <> | Subject | [PATCH v2 0/2] sched, xfs: Add PF_MEMALLOC_NOLOCKDEP to fix lockdep problem in xfs | Date | Wed, 17 Jun 2020 13:53:08 -0400 |
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v2: - Update patch to add the frozen flag check as the XFS_TRANS_NO_WRITECOUNT check alone is insufficient.
There is a false positive lockdep warning in how the xfs code handle filesystem freeze:
Possible unsafe locking scenario:
CPU0 CPU1 ---- ---- lock(sb_internal); lock(fs_reclaim); lock(sb_internal); lock(fs_reclaim);
*** DEADLOCK ***
This patch series works around this problem by adding a PF_MEMALLOC_NOLOCKDEP flag and set during filesystem freeze to avoid the lockdep splat.
Waiman Long (2): sched: Add PF_MEMALLOC_NOLOCKDEP flag xfs: Fix false positive lockdep warning with sb_internal & fs_reclaim
fs/xfs/xfs_log.c | 9 +++++++++ fs/xfs/xfs_trans.c | 31 +++++++++++++++++++++++++++---- include/linux/sched.h | 7 +++++++ include/linux/sched/mm.h | 15 ++++++++++----- 4 files changed, 53 insertions(+), 9 deletions(-)
-- 2.18.1
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