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authorTheodore Ts'o <tytso@mit.edu>2021-08-14 17:54:09 +0300
committerTheodore Ts'o <tytso@mit.edu>2021-08-31 06:36:50 +0300
commitb33d9f5909c8d30f1429fb9aefbb32760901a023 (patch)
tree76a9e8fe80b30e7e169f6e2cd5c6b1e909fa8dbe
parenta5fda11338180db13f3e9eec20c9deda1f7bad72 (diff)
downloadlinux-b33d9f5909c8d30f1429fb9aefbb32760901a023.tar.xz
jbd2: add sparse annotations for add_transaction_credits()
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
-rw-r--r--fs/jbd2/transaction.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 8804e126805f..5347411ae13e 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -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 @@ repeat:
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