Messages in this thread | | | Subject | Re: [PATCH v3 1/1] vfs: iversion truncate bug fix | From | Mimi Zohar <> | Date | Wed, 04 Jan 2012 23:17:12 -0500 |
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On Wed, 2012-01-04 at 18:06 -0800, Greg KH wrote: > On Wed, Jan 04, 2012 at 04:46:38PM -0800, Andrew Morton wrote: > > On Wed, 04 Jan 2012 19:33:49 -0500 > > Mimi Zohar <zohar@linux.vnet.ibm.com> wrote: > > > > > On Wed, 2012-01-04 at 15:28 -0800, Andrew Morton wrote: > > > > On Thu, 22 Dec 2011 08:26:30 -0500 > > > > Mimi Zohar <zohar@linux.vnet.ibm.com> wrote: > > > > > > > > > On Thu, 2011-12-22 at 12:54 +0200, Dmitry Kasatkin wrote: > > > > > > 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. > > > > > > > > > > > > Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> > > > > > > > > > > Acked-by: Mimi Zohar <zohar@us.ibm.com> > > > > > (Stable should be cc'ed on this patch.) > > > > > > > > why? > > > > > > Why backported? > > > > Yes. If you want to submit the patch to the -stable maintainer then > > you should explain to him why the fix is important enough to warrant > > doing that. That involves explaining the user-visible effects of > > the bug. > > > > > The IMA measurement list could be incomplete. > > > > In more detail than this. Maybe he knows what the above sentence > > means, but I sure don't. > > Nope, I don't either :)
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.
Mimi
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