From 1eaa566d368b214d99cbb973647c1b0b8102a9ae Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 30 Jun 2016 11:40:54 -0400 Subject: [PATCH] jbd2: track more dependencies on transaction commit So far we were tracking only dependency on transaction commit due to starting a new handle (which may require commit to start a new transaction). Now add tracking also for other cases where we wait for transaction commit. This way lockdep can catch deadlocks e. g. because we call jbd2_journal_stop() for a synchronous handle with some locks held which rank below transaction start. Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o --- fs/jbd2/journal.c | 1 + fs/jbd2/transaction.c | 4 ++++ include/linux/jbd2.h | 6 ++++++ 3 files changed, 11 insertions(+) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 208e4058040b..fc1d7a39b082 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -691,6 +691,7 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid) { int err = 0; + jbd2_might_wait_for_commit(journal); read_lock(&journal->j_state_lock); #ifdef CONFIG_JBD2_DEBUG if (!tid_geq(journal->j_commit_request, tid)) { diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index c0065040c5be..b5bc3e249163 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -182,6 +182,8 @@ static int add_transaction_credits(journal_t *journal, int blocks, int needed; int total = blocks + rsv_blocks; + jbd2_might_wait_for_commit(journal); + /* * If the current transaction is locked down for commit, wait * for the lock to be released. @@ -695,6 +697,8 @@ void jbd2_journal_lock_updates(journal_t *journal) { DEFINE_WAIT(wait); + jbd2_might_wait_for_commit(journal); + write_lock(&journal->j_state_lock); ++journal->j_barrier_count; diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 3d210cbe4e1b..dfaa1f4dcb0c 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -1046,6 +1046,12 @@ struct journal_s #endif }; +#define jbd2_might_wait_for_commit(j) \ + do { \ + rwsem_acquire(&j->j_trans_commit_map, 0, 0, _THIS_IP_); \ + rwsem_release(&j->j_trans_commit_map, 1, _THIS_IP_); \ + } while (0) + /* journal feature predicate functions */ #define JBD2_FEATURE_COMPAT_FUNCS(name, flagname) \ static inline bool jbd2_has_feature_##name(journal_t *j) \