Re: Re: Re: EXT4 regression caused 4eec7

[EUNBONG SONG <eunb.song@samsung.com>]

>> Since at this point it's safer to rollback the change and we can
>> investigate more deeply how to fix it correctly for the next
>> development cycle, this is the patch which I'm testing.

>>                     - Ted

> Hello, I've tested with your patch. But the same problem was reproduced.
> Currently, I'm trying to git bisect. If i done git bisect, i will let you know.

Hi, I've done git bisect. and panic at jbd2_journal_put_journal_head() is caused by 
ae4647fb7654676fc44a97e86eb35f9f06b99f66: "jbd2: reduce journal_head size."
I write just code patch which revert ae4647fb7654676fc44a97e86eb35f9f06b99f66 because
I don't know the root cause. 


Signed-off-by: Eunbong Song <eunb.song@samsung.com>
---
 include/linux/journal-head.h |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/linux/journal-head.h b/include/linux/journal-head.h
index 13a3da2..c18b46f 100644
--- a/include/linux/journal-head.h
+++ b/include/linux/journal-head.h
@@ -31,14 +31,21 @@ struct journal_head {
 	/*
 	 * Journalling list for this buffer [jbd_lock_bh_state()]
 	 */
-	unsigned b_jlist:4;
+	unsigned b_jlist;
 
 	/*
 	 * This flag signals the buffer has been modified by
 	 * the currently running transaction
 	 * [jbd_lock_bh_state()]
 	 */
-	unsigned b_modified:1;
+	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;
 
 	/*
 	 * Copy of the buffer data frozen for writing to the log.
-- 
1.7.0.4


Thanks.