@@ -223,9 +223,15 @@ static void sub_reserved_credits(journal_t *journal, int blocks)
* with j_state_lock held for reading. Returns 0 if handle joined the running
* transaction. Returns 1 if we had to wait, j_state_lock is dropped, and
* caller must retry.
+ *
+ * Note: because j_state_lock may be dropped depending on the return
+ * value, we need to fake out sparse so ti doesn't complain about a
+ * locking imbalance. Callers of add_transaction_credits will need to
+ * make a similar accomodation.
*/
static int add_transaction_credits(journal_t *journal, int blocks,
int rsv_blocks)
+__must_hold(&journal->j_state_lock)
{
transaction_t *t = journal->j_running_transaction;
int needed;
@@ -238,6 +244,7 @@ static int add_transaction_credits(journal_t *journal, int blocks,
if (t->t_state != T_RUNNING) {
WARN_ON_ONCE(t->t_state >= T_FLUSH);
wait_transaction_locked(journal);
+ __acquire(&journal->j_state_lock); /* fake out sparse */
return 1;
}
@@ -266,10 +273,12 @@ static int add_transaction_credits(journal_t *journal, int blocks,
wait_event(journal->j_wait_reserved,
atomic_read(&journal->j_reserved_credits) + total <=
journal->j_max_transaction_buffers);
+ __acquire(&journal->j_state_lock); /* fake out sparse */
return 1;
}
wait_transaction_locked(journal);
+ __acquire(&journal->j_state_lock); /* fake out sparse */
return 1;
}
@@ -293,6 +302,7 @@ static int add_transaction_credits(journal_t *journal, int blocks,
journal->j_max_transaction_buffers)
__jbd2_log_wait_for_space(journal);
write_unlock(&journal->j_state_lock);
+ __acquire(&journal->j_state_lock); /* fake out sparse */
return 1;
}
@@ -310,6 +320,7 @@ static int add_transaction_credits(journal_t *journal, int blocks,
wait_event(journal->j_wait_reserved,
atomic_read(&journal->j_reserved_credits) + rsv_blocks
<= journal->j_max_transaction_buffers / 2);
+ __acquire(&journal->j_state_lock); /* fake out sparse */
return 1;
}
return 0;
@@ -413,8 +424,14 @@ static int start_this_handle(journal_t *journal, handle_t *handle,
if (!handle->h_reserved) {
/* We may have dropped j_state_lock - restart in that case */
- if (add_transaction_credits(journal, blocks, rsv_blocks))
+ if (add_transaction_credits(journal, blocks, rsv_blocks)) {
+ /*
+ * add_transaction_credits releases
+ * j_state_lock on a non-zero return
+ */
+ __release(&journal->j_state_lock);
goto repeat;
+ }
} else {
/*
* We have handle reserved so we are allowed to join T_LOCKED
Signed-off-by: Theodore Ts'o <tytso@mit.edu> --- fs/jbd2/transaction.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)