2010-11-16 16:54:19

by Prasad Joshi

Subject: [PATCH 1/1] LogFS: Kernel BUG at readwrite.c:1193

This happens when __logfs_create() tries to write a new inode to the
disk which is full.

__logfs_create() associates the transaction pointer with inode. During
the logfs_write_inode() function call chain this transaction pointer
is moved from inode to page->private using function move_inode_to_page
(do_write_inode() -> inode_to_page() -> move_inode_to_page)

When the write inode fails, the transaction is aborted and iput is
called on the failed inode. During delete_inode the same transaction
pointer associated with the page is getting used. Thus causing kernel
BUG.

The patch checks for error in write_inode() and restores the
page->private to NULL.


Signed-off-by: Prasad Joshi <[email protected]>
---
diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
index 6127baf..ee99a9f 100644
--- a/fs/logfs/readwrite.c
+++ b/fs/logfs/readwrite.c
@@ -1994,6 +1994,9 @@ static int do_write_inode(struct inode *inode)

/* FIXME: transaction is part of logfs_block now. Is that enough? */
err = logfs_write_buf(master_inode, page, 0);
+ if (err)
+ move_page_to_inode(inode, page);
+
logfs_put_write_page(page);
return err;
}



---------- Forwarded message ----------
From: <[email protected]>
Date: Tue, Nov 16, 2010 at 3:20 PM
Subject: [Bug 20162] [LogFS][2.6.36.rc7+] Kernel BUG at readwrite.c:1193
To: [email protected]


https://bugzilla.kernel.org/show_bug.cgi?id=20162


Florian Mickler <[email protected]> changed:

? ? ? ? ? What ? ?|Removed ? ? ? ? ? ? ? ? ? ? |Added
----------------------------------------------------------------------------
? ? ? ? ? ? Status|NEW ? ? ? ? ? ? ? ? ? ? ? ? |RESOLVED
? ? ? ? ? ? ? ? CC| ? ? ? ? ? ? ? ? ? ? ? ? ? ?|[email protected]
? ? ? ? Resolution| ? ? ? ? ? ? ? ? ? ? ? ? ? ?|PATCH_ALREADY_AVAILABLE




--- Comment #2 from Florian Mickler <[email protected]> ?2010-11-16
15:20:46 ---
Can you submit that patch to lkml and cc the logfs maintainer and the logfs
list?
(Joern Engel <[email protected]>, [email protected], [email protected])

See Documentation/SubmittingPatches

Patch: https://bugzilla.kernel.org/show_bug.cgi?id=20162#c1

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2010-12-06 17:10:16

by Florian Mickler

Subject: Re: [PATCH 1/1] LogFS: Kernel BUG at readwrite.c:1193

Hi,

On Tue, 16 Nov 2010 16:54:17 +0000
Prasad Joshi <[email protected]> wrote:

> This happens when __logfs_create() tries to write a new inode to the
> disk which is full.
>
> __logfs_create() associates the transaction pointer with inode. During
> the logfs_write_inode() function call chain this transaction pointer
> is moved from inode to page->private using function move_inode_to_page
> (do_write_inode() -> inode_to_page() -> move_inode_to_page)
>
> When the write inode fails, the transaction is aborted and iput is
> called on the failed inode. During delete_inode the same transaction
> pointer associated with the page is getting used. Thus causing kernel
> BUG.
>
> The patch checks for error in write_inode() and restores the
> page->private to NULL.
>
>



This fixes https://bugzilla.kernel.org/show_bug.cgi?id=20162 . Can
someone please review? Any comments?



> Signed-off-by: Prasad Joshi <[email protected]>
> ---
> diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
> index 6127baf..ee99a9f 100644
> --- a/fs/logfs/readwrite.c
> +++ b/fs/logfs/readwrite.c
> @@ -1994,6 +1994,9 @@ static int do_write_inode(struct inode *inode)
>
> /* FIXME: transaction is part of logfs_block now. Is that enough? */
> err = logfs_write_buf(master_inode, page, 0);
> + if (err)
> + move_page_to_inode(inode, page);
> +
> logfs_put_write_page(page);
> return err;
> }
>
>
>
> ---------- Forwarded message ----------
> From: <[email protected]>
> Date: Tue, Nov 16, 2010 at 3:20 PM
> Subject: [Bug 20162] [LogFS][2.6.36.rc7+] Kernel BUG at readwrite.c:1193
> To: [email protected]
>
>
> https://bugzilla.kernel.org/show_bug.cgi?id=20162
>
>
> Florian Mickler <[email protected]> changed:
>
> ? ? ? ? ? What ? ?|Removed ? ? ? ? ? ? ? ? ? ? |Added
> ----------------------------------------------------------------------------
> ? ? ? ? ? ? Status|NEW ? ? ? ? ? ? ? ? ? ? ? ? |RESOLVED
> ? ? ? ? ? ? ? ? CC| ? ? ? ? ? ? ? ? ? ? ? ? ? ?|[email protected]
> ? ? ? ? Resolution| ? ? ? ? ? ? ? ? ? ? ? ? ? ?|PATCH_ALREADY_AVAILABLE
>
>
>
>
> --- Comment #2 from Florian Mickler <[email protected]> ?2010-11-16
> 15:20:46 ---
> Can you submit that patch to lkml and cc the logfs maintainer and the logfs
> list?
> (Joern Engel <[email protected]>, [email protected], [email protected])
>
> See Documentation/SubmittingPatches
>
> Patch: https://bugzilla.kernel.org/show_bug.cgi?id=20162#c1
>
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> Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
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