jbd2: make jbd2_journal_get_max_txn_bufs() internal

There's no reason to have jbd2_journal_get_max_txn_bufs() public
function. Currently all users are internal and can use
journal->j_max_transaction_buffers instead. This saves some unnecessary
recomputations of the limit as a bonus which becomes important as this
function gets more complex in the following patch.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20240624170127.3253-1-jack@suse.czSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/jbd2/commit.c

@@ -766,7 +766,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 		if (first_block < journal->j_tail)
 			freed += journal->j_last - journal->j_first;
 		/* Update tail only if we free significant amount of space */
-		if (freed < jbd2_journal_get_max_txn_bufs(journal))
+		if (freed < journal->j_max_transaction_buffers)
 			update_tail = 0;
 	}
 	J_ASSERT(commit_transaction->t_state == T_COMMIT);

fs/jbd2/journal.c

@@ -1674,6 +1674,11 @@ journal_t *jbd2_journal_init_inode(struct inode *inode)
 	return journal;
 }
 
+static int jbd2_journal_get_max_txn_bufs(journal_t *journal)
+{
+	return (journal->j_total_len - journal->j_fc_wbufsize) / 4;
+}
+
 /*
  * Given a journal_t structure, initialise the various fields for
  * startup of a new journaling session.  We use this both when creating

include/linux/jbd2.h

@@ -1660,11 +1660,6 @@ int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode);
 int jbd2_fc_wait_bufs(journal_t *journal, int num_blks);
 int jbd2_fc_release_bufs(journal_t *journal);
 
-static inline int jbd2_journal_get_max_txn_bufs(journal_t *journal)
-{
-	return (journal->j_total_len - journal->j_fc_wbufsize) / 4;
-}
-
 /*
  * is_journal_abort
  *