xfs: fix double free of inode

If we fail to initialise the VFS inode in inode_init_always(),
it will call ->delete_inode internally resulting in the inode being
freed. Hence we need to delay the call to inode_init_always()
until after the XFS inode is sufficient set up to handle a
call to ->delete_inode, and then if that fails do not touch
the inode again at all as it has been freed.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Dave Chinner 2009-04-06 18:40:17 +02:00 committed by Christoph Hellwig
parent a6cb767e24
commit 705db3fd46

View File

@ -69,15 +69,6 @@ xfs_inode_alloc(
ASSERT(!spin_is_locked(&ip->i_flags_lock));
ASSERT(completion_done(&ip->i_flush));
/*
* initialise the VFS inode here to get failures
* out of the way early.
*/
if (!inode_init_always(mp->m_super, VFS_I(ip))) {
kmem_zone_free(xfs_inode_zone, ip);
return NULL;
}
/* initialise the xfs inode */
ip->i_ino = ino;
ip->i_mount = mp;
@ -113,6 +104,20 @@ xfs_inode_alloc(
#ifdef XFS_DIR2_TRACE
ip->i_dir_trace = ktrace_alloc(XFS_DIR2_KTRACE_SIZE, KM_NOFS);
#endif
/*
* Now initialise the VFS inode. We do this after the xfs_inode
* initialisation as internal failures will result in ->destroy_inode
* being called and that will pass down through the reclaim path and
* free the XFS inode. This path requires the XFS inode to already be
* initialised. Hence if this call fails, the xfs_inode has already
* been freed and we should not reference it at all in the error
* handling.
*/
if (!inode_init_always(mp->m_super, VFS_I(ip)))
return NULL;
/* prevent anyone from using this yet */
VFS_I(ip)->i_state = I_NEW|I_LOCK;
return ip;
}