vfs: increment iversion when a file is truncated

When a file is truncated with truncate()/ftruncate() and then closed,
iversion is not updated.  This patch uses ATTR_SIZE flag as an indication
to increment iversion.

Mimi said:

On fput(), i_version is used to detect and flag files that have changed
and need to be re-measured in the IMA measurement policy.  When a file
is truncated with truncate()/ftruncate() and then closed, i_version is
not updated.  As a result, although the file has changed, it will not be
re-measured and added to the IMA measurement list on subsequent access.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Dmitry Kasatkin 2012-05-29 11:02:21 -07:00 committed by Al Viro
parent a0a9b04337
commit 799243a389

View File

@ -176,6 +176,11 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
return -EPERM;
}
if ((ia_valid & ATTR_SIZE) && IS_I_VERSION(inode)) {
if (attr->ia_size != inode->i_size)
inode_inc_iversion(inode);
}
if ((ia_valid & ATTR_MODE)) {
umode_t amode = attr->ia_mode;
/* Flag setting protected by i_mutex */