4.19-stable review patch. If anyone has any objections, please let me know.
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From: Jack Wang jinpu.wang@profitbricks.com
[ Upstream commit 6aaa58c994277647f8b05ffef3b9b225a2d08f36 ]
I noticed kmemleak report memory leak when run create/stop md in a loop, backtrace: [<000000001ca975e7>] mempool_create_node+0x86/0xd0 [<0000000095576bcd>] md_run+0x1057/0x1410 [md_mod] [<000000007b45c5fc>] do_md_run+0x15/0x130 [md_mod] [<000000001ede9ec0>] md_ioctl+0x1f49/0x25d0 [md_mod] [<000000004142cacf>] blkdev_ioctl+0x680/0xd00
The root cause is we alloc mddev->flush_pool and mddev->flush_bio_pool in md_run, but from do_md_stop will not call into md_stop but __md_stop, move the mempool_destroy to __md_stop fixes the problem for me.
The bug was introduced in 5a409b4f56d5, the fixes should go to 4.18+
Fixes: 5a409b4f56d5 ("MD: fix lock contention for flush bios") Signed-off-by: Jack Wang jinpu.wang@profitbricks.com Reviewed-by: Xiao Ni xni@redhat.com Signed-off-by: Shaohua Li shli@fb.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/md.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
--- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5906,14 +5906,6 @@ static void __md_stop(struct mddev *mdde mddev->to_remove = &md_redundancy_group; module_put(pers->owner); clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); -} - -void md_stop(struct mddev *mddev) -{ - /* stop the array and free an attached data structures. - * This is called from dm-raid - */ - __md_stop(mddev); if (mddev->flush_bio_pool) { mempool_destroy(mddev->flush_bio_pool); mddev->flush_bio_pool = NULL; @@ -5922,6 +5914,14 @@ void md_stop(struct mddev *mddev) mempool_destroy(mddev->flush_pool); mddev->flush_pool = NULL; } +} + +void md_stop(struct mddev *mddev) +{ + /* stop the array and free an attached data structures. + * This is called from dm-raid + */ + __md_stop(mddev); bioset_exit(&mddev->bio_set); bioset_exit(&mddev->sync_set); }