Re: [PATCH] UDF: fix deadlock on inode being dropped

From: Cyrill Gorcunov
Date: Thu Jun 07 2007 - 09:56:37 EST


[Jan Kara - Thu, Jun 07, 2007 at 11:36:07AM +0200]
| Hi Cyrill!
|
| On Wed 06-06-07 21:53:51, Cyrill Gorcunov wrote:
| > This patch prevents from deadlock on inode being dropped.
| > The deadlock is caused by inderect call of mark_inode_dirty()
| > within udf_drop_inode() but inode lock is already kept
| > by the kernel. So moving code from udf_drop_inode() to
| > udf_delete_inode() we save its functionality and avoid
| > deadlock.
| The patch is wrong. You cannot truncate the extent just in delete_inode.
| That would lead to inodes with untruncated last extent on disk after
| unmounting, which is forbidden in the specification. You need to truncate
| the last extent whenever inode is being removed from memory or something
| like that... I'm already thinking how to do it and avoid calling
| mark_inode_dirty()...
|
|
| Honza
| --
| Jan Kara <jack@xxxxxxx>
| SuSE CR Labs
|

Arh, thanks... Jan, actually the reason I've moved the code into
'delete' section was that I found no reasonable difference for our
case between 'drop' and 'delete'. Moreover, by seeing into VFS code
the only diff between 'drop' and 'delete' is that
inside generic_delete_inode() a few inode structure elements
are being destroyed and then our udf_drop_inode is called. So assuming,
that you're right in drop_inode I've code just moved to 'delete' section.

Cyrill

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