From ae4647fb7654676fc44a97e86eb35f9f06b99f66 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 12 Apr 2013 00:03:42 -0400 Subject: [PATCH] jbd2: reduce journal_head size Remove unused t_cow_tid field (ext4 copy-on-write support doesn't seem to be happening) and change b_modified and b_jlist to bitfields thus saving 8 bytes in the structure. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" Reviewed-by: Zheng Liu --- include/linux/journal-head.h | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/include/linux/journal-head.h b/include/linux/journal-head.h index c18b46f8aeeb..13a3da25ff07 100644 --- a/include/linux/journal-head.h +++ b/include/linux/journal-head.h @@ -31,21 +31,14 @@ struct journal_head { /* * Journalling list for this buffer [jbd_lock_bh_state()] */ - unsigned b_jlist; + unsigned b_jlist:4; /* * This flag signals the buffer has been modified by * the currently running transaction * [jbd_lock_bh_state()] */ - unsigned b_modified; - - /* - * This feild tracks the last transaction id in which this buffer - * has been cowed - * [jbd_lock_bh_state()] - */ - tid_t b_cow_tid; + unsigned b_modified:1; /* * Copy of the buffer data frozen for writing to the log. -- 2.39.5