From: Zhihao Cheng chengzhihao1@huawei.com
[ Upstream commit 944e096aa24071d3fe22822f6249d3ae309e39ea ]
Dirty znodes will be written on flash in committing process with following states:
process A | znode state ------------------------------------------------------ do_commit | DIRTY_ZNODE ubifs_tnc_start_commit | DIRTY_ZNODE get_znodes_to_commit | DIRTY_ZNODE | COW_ZNODE layout_commit | DIRTY_ZNODE | COW_ZNODE fill_gap | 0 write master | 0 or OBSOLETE_ZNODE
process B | znode state ------------------------------------------------------ do_commit | DIRTY_ZNODE[1] ubifs_tnc_start_commit | DIRTY_ZNODE get_znodes_to_commit | DIRTY_ZNODE | COW_ZNODE ubifs_tnc_end_commit | DIRTY_ZNODE | COW_ZNODE write_index | 0 write master | 0 or OBSOLETE_ZNODE[2] or | DIRTY_ZNODE[3]
[1] znode is dirtied without concurrent committing process [2] znode is copied up (re-dirtied by other process) before cleaned up in committing process [3] znode is re-dirtied after cleaned up in committing process
Currently, the clean znode count is updated in free_obsolete_znodes(), which is called only in normal path. If do_commit failed, clean znode count won't be updated, which triggers a failure ubifs assertion[4] in ubifs_tnc_close(): ubifs_assert_failed [ubifs]: UBIFS assert failed: freed == n
[4] Commit 380347e9ca7682 ("UBIFS: Add an assertion for clean_zn_cnt").
Fix it by re-statisticing cleaned znode count in tnc_destroy_cnext().
Fetch a reproducer in [Link].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216704 Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ubifs/tnc.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c index c7828db206bc0..20b70e178c4fa 100644 --- a/fs/ubifs/tnc.c +++ b/fs/ubifs/tnc.c @@ -3044,6 +3044,21 @@ static void tnc_destroy_cnext(struct ubifs_info *c) cnext = cnext->cnext; if (ubifs_zn_obsolete(znode)) kfree(znode); + else if (!ubifs_zn_cow(znode)) { + /* + * Don't forget to update clean znode count after + * committing failed, because ubifs will check this + * count while closing tnc. Non-obsolete znode could + * be re-dirtied during committing process, so dirty + * flag is untrustable. The flag 'COW_ZNODE' is set + * for each dirty znode before committing, and it is + * cleared as long as the znode become clean, so we + * can statistic clean znode count according to this + * flag. + */ + atomic_long_inc(&c->clean_zn_cnt); + atomic_long_inc(&ubifs_clean_zn_cnt); + } } while (cnext && cnext != c->cnext); }