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 <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 208e405..fc1d7a3 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -691,6 +691,7 @@
{
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 c006504..b5bc3e2 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -182,6 +182,8 @@
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 @@
{
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 3d210cb..dfaa1f4 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1046,6 +1046,12 @@
#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) \