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* [PATCH] ext3: Don't warn from writepage when readonly inode is spotted after error
@ 2011-12-22 15:56 Jan Kara
  2011-12-22 16:11 ` Eric Sandeen
  0 siblings, 1 reply; 3+ messages in thread
From: Jan Kara @ 2011-12-22 15:56 UTC (permalink / raw)
  To: linux-ext4; +Cc: Jan Kara

WARN_ON_ONCE(IS_RDONLY(inode)) tends to trip when filesystem hits error and is
remounted read-only. This unnecessarily scares users (well, they should be
scared because of filesystem error, but the stack trace distracts them from the
right source of their fear ;-). We could as well just remove the WARN_ON but
it's not hard to fix it to not trip on filesystem with errors and not use more
cycles in the common case so that's what we do.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext3/inode.c |   18 +++++++++++++++---
 1 files changed, 15 insertions(+), 3 deletions(-)

  I carry this patch in my tree and will merge it with Linus in the next merge
window if noone objects.

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index a8d3217..91ac85b 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1623,7 +1623,11 @@ static int ext3_ordered_writepage(struct page *page,
 	int err;
 
 	J_ASSERT(PageLocked(page));
-	WARN_ON_ONCE(IS_RDONLY(inode));
+	/*
+	 * We don't want to warn for emergency remount. The condition is ordered to avoid
+	 * dereferencing inode->i_sb in non-error case to avoid slow-downs.
+	 */
+	WARN_ON_ONCE(IS_RDONLY(inode) && !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
 
 	/*
 	 * We give up here if we're reentered, because it might be for a
@@ -1698,7 +1702,11 @@ static int ext3_writeback_writepage(struct page *page,
 	int err;
 
 	J_ASSERT(PageLocked(page));
-	WARN_ON_ONCE(IS_RDONLY(inode));
+	/*
+	 * We don't want to warn for emergency remount. The condition is ordered to avoid
+	 * dereferencing inode->i_sb in non-error case to avoid slow-downs.
+	 */
+	WARN_ON_ONCE(IS_RDONLY(inode) && !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
 
 	if (ext3_journal_current_handle())
 		goto out_fail;
@@ -1741,7 +1749,11 @@ static int ext3_journalled_writepage(struct page *page,
 	int err;
 
 	J_ASSERT(PageLocked(page));
-	WARN_ON_ONCE(IS_RDONLY(inode));
+	/*
+	 * We don't want to warn for emergency remount. The condition is ordered to avoid
+	 * dereferencing inode->i_sb in non-error case to avoid slow-downs.
+	 */
+	WARN_ON_ONCE(IS_RDONLY(inode) && !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
 
 	if (ext3_journal_current_handle())
 		goto no_write;
-- 
1.7.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] ext3: Don't warn from writepage when readonly inode is spotted after error
  2011-12-22 15:56 [PATCH] ext3: Don't warn from writepage when readonly inode is spotted after error Jan Kara
@ 2011-12-22 16:11 ` Eric Sandeen
  2011-12-22 16:18   ` Jan Kara
  0 siblings, 1 reply; 3+ messages in thread
From: Eric Sandeen @ 2011-12-22 16:11 UTC (permalink / raw)
  To: Jan Kara; +Cc: linux-ext4

On 12/22/11 9:56 AM, Jan Kara wrote:
> WARN_ON_ONCE(IS_RDONLY(inode)) tends to trip when filesystem hits error and is
> remounted read-only. This unnecessarily scares users (well, they should be
> scared because of filesystem error, but the stack trace distracts them from the
> right source of their fear ;-). We could as well just remove the WARN_ON but
> it's not hard to fix it to not trip on filesystem with errors and not use more
> cycles in the common case so that's what we do.

I've seen that too and it is distracting.

Looks good to me, aside from the rather long lines ;)

-Eric


> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
>  fs/ext3/inode.c |   18 +++++++++++++++---
>  1 files changed, 15 insertions(+), 3 deletions(-)
> 
>   I carry this patch in my tree and will merge it with Linus in the next merge
> window if noone objects.
> 
> diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
> index a8d3217..91ac85b 100644
> --- a/fs/ext3/inode.c
> +++ b/fs/ext3/inode.c
> @@ -1623,7 +1623,11 @@ static int ext3_ordered_writepage(struct page *page,
>  	int err;
>  
>  	J_ASSERT(PageLocked(page));
> -	WARN_ON_ONCE(IS_RDONLY(inode));
> +	/*
> +	 * We don't want to warn for emergency remount. The condition is ordered to avoid
> +	 * dereferencing inode->i_sb in non-error case to avoid slow-downs.
> +	 */
> +	WARN_ON_ONCE(IS_RDONLY(inode) && !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
>  
>  	/*
>  	 * We give up here if we're reentered, because it might be for a
> @@ -1698,7 +1702,11 @@ static int ext3_writeback_writepage(struct page *page,
>  	int err;
>  
>  	J_ASSERT(PageLocked(page));
> -	WARN_ON_ONCE(IS_RDONLY(inode));
> +	/*
> +	 * We don't want to warn for emergency remount. The condition is ordered to avoid
> +	 * dereferencing inode->i_sb in non-error case to avoid slow-downs.
> +	 */
> +	WARN_ON_ONCE(IS_RDONLY(inode) && !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
>  
>  	if (ext3_journal_current_handle())
>  		goto out_fail;
> @@ -1741,7 +1749,11 @@ static int ext3_journalled_writepage(struct page *page,
>  	int err;
>  
>  	J_ASSERT(PageLocked(page));
> -	WARN_ON_ONCE(IS_RDONLY(inode));
> +	/*
> +	 * We don't want to warn for emergency remount. The condition is ordered to avoid
> +	 * dereferencing inode->i_sb in non-error case to avoid slow-downs.
> +	 */
> +	WARN_ON_ONCE(IS_RDONLY(inode) && !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
>  
>  	if (ext3_journal_current_handle())
>  		goto no_write;


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] ext3: Don't warn from writepage when readonly inode is spotted after error
  2011-12-22 16:11 ` Eric Sandeen
@ 2011-12-22 16:18   ` Jan Kara
  0 siblings, 0 replies; 3+ messages in thread
From: Jan Kara @ 2011-12-22 16:18 UTC (permalink / raw)
  To: Eric Sandeen; +Cc: Jan Kara, linux-ext4

On Thu 22-12-11 10:11:36, Eric Sandeen wrote:
> On 12/22/11 9:56 AM, Jan Kara wrote:
> > WARN_ON_ONCE(IS_RDONLY(inode)) tends to trip when filesystem hits error and is
> > remounted read-only. This unnecessarily scares users (well, they should be
> > scared because of filesystem error, but the stack trace distracts them from the
> > right source of their fear ;-). We could as well just remove the WARN_ON but
> > it's not hard to fix it to not trip on filesystem with errors and not use more
> > cycles in the common case so that's what we do.
> 
> I've seen that too and it is distracting.
> 
> Looks good to me, aside from the rather long lines ;)
  Ah, right. My internal style checker had a coffee break I assume ;).
Below is a version with long lines fixed.

									Honza

>From 0588350bf10c8dad70cc299971dfdeec10754b29 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Thu, 22 Dec 2011 16:49:05 +0100
Subject: [PATCH] ext3: Don't warn from writepage when readonly inode is spotted after error

WARN_ON_ONCE(IS_RDONLY(inode)) tends to trip when filesystem hits error and is
remounted read-only. This unnecessarily scares users (well, they should be
scared because of filesystem error, but the stack trace distracts them from the
right source of their fear ;-). We could as well just remove the WARN_ON but
it's not hard to fix it to not trip on filesystem with errors and not use more
cycles in the common case so that's what we do.

CC: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext3/inode.c |   24 +++++++++++++++++++++---
 1 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index a8d3217..fbf6599 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1623,7 +1623,13 @@ static int ext3_ordered_writepage(struct page *page,
 	int err;
 
 	J_ASSERT(PageLocked(page));
-	WARN_ON_ONCE(IS_RDONLY(inode));
+	/*
+	 * We don't want to warn for emergency remount. The condition is
+	 * ordered to avoid dereferencing inode->i_sb in non-error case to
+	 * avoid slow-downs.
+	 */
+	WARN_ON_ONCE(IS_RDONLY(inode) &&
+		     !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
 
 	/*
 	 * We give up here if we're reentered, because it might be for a
@@ -1698,7 +1704,13 @@ static int ext3_writeback_writepage(struct page *page,
 	int err;
 
 	J_ASSERT(PageLocked(page));
-	WARN_ON_ONCE(IS_RDONLY(inode));
+	/*
+	 * We don't want to warn for emergency remount. The condition is
+	 * ordered to avoid dereferencing inode->i_sb in non-error case to
+	 * avoid slow-downs.
+	 */
+	WARN_ON_ONCE(IS_RDONLY(inode) &&
+		     !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
 
 	if (ext3_journal_current_handle())
 		goto out_fail;
@@ -1741,7 +1753,13 @@ static int ext3_journalled_writepage(struct page *page,
 	int err;
 
 	J_ASSERT(PageLocked(page));
-	WARN_ON_ONCE(IS_RDONLY(inode));
+	/*
+	 * We don't want to warn for emergency remount. The condition is
+	 * ordered to avoid dereferencing inode->i_sb in non-error case to
+	 * avoid slow-downs.
+	 */
+	WARN_ON_ONCE(IS_RDONLY(inode) &&
+		     !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
 
 	if (ext3_journal_current_handle())
 		goto no_write;
-- 
1.7.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2011-12-22 16:19 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2011-12-22 15:56 [PATCH] ext3: Don't warn from writepage when readonly inode is spotted after error Jan Kara
2011-12-22 16:11 ` Eric Sandeen
2011-12-22 16:18   ` Jan Kara

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