Re: JFFS2 issue with v3.5.x and later on Atmel chips at least (was:Kernel oops since v3.5.x on Atmel chips)

From: Artem Bityutskiy
Date: Thu Aug 23 2012 - 03:36:45 EST


From: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
Date: Thu, 23 Aug 2012 10:10:07 +0300
Subject: [PATCH] JFFS2: fix unmount regression

This patch fixes regression introduced by
"8bdc81c jffs2: get rid of jffs2_sync_super". We submit a delayed work in order
to make sure the write-buffer is synchronized at some point. But we do not
flush it when we unmount, which causes an oops when we unmount the file-system
and then the delayed work is executed.

This patch fixes the issue by adding a "cancel_delayed_work_sync()" infocation
in the '->sync_fs()' handler. This will make sure the delayed work is canceled
on sync, unmount and re-mount. And because VFS always callse 'sync_fs()' before
unmounting or remounting, this fixes the issue.

Reported-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx [3.5+]
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
---

Ludovic, would you please give this patch a test? Also attached.

fs/jffs2/super.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index 61ea413..e385fa3 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -100,6 +100,9 @@ static int jffs2_sync_fs(struct super_block *sb, int wait)
{
struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

+ if (IS_ENABLED(CONFIG_JFFS2_FS_WRITEBUFFER))
+ cancel_delayed_work_sync(&c->wbuf_dwork);
+
mutex_lock(&c->alloc_sem);
jffs2_flush_wbuf_pad(c);
mutex_unlock(&c->alloc_sem);
--
1.7.10.4
From 2f1554d01f7db58631f9da7dd19a7254d1096feb Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
Date: Thu, 23 Aug 2012 10:10:07 +0300
Subject: [PATCH] JFFS2: fix unmount regression

This patch fixes regression introduced by
"8bdc81c jffs2: get rid of jffs2_sync_super". We submit a delayed work in order
to make sure the write-buffer is synchronized at some point. But we do not
flush it when we unmount, which causes an oops when we unmount the file-system
and then the delayed work is executed.

This patch fixes the issue by adding a "cancel_delayed_work_sync()" infocation
in the '->sync_fs()' handler. This will make sure the delayed work is canceled
on sync, unmount and re-mount. And because VFS always callse 'sync_fs()' before
unmounting or remounting, this fixes the issue.

Reported-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx [3.5+]
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
---
fs/jffs2/super.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index 61ea413..e385fa3 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -100,6 +100,9 @@ static int jffs2_sync_fs(struct super_block *sb, int wait)
{
struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

+ if (IS_ENABLED(CONFIG_JFFS2_FS_WRITEBUFFER))
+ cancel_delayed_work_sync(&c->wbuf_dwork);
+
mutex_lock(&c->alloc_sem);
jffs2_flush_wbuf_pad(c);
mutex_unlock(&c->alloc_sem);
--
1.7.10.4

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