linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Amir Goldstein <amir73il@gmail.com>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	Vivek Goyal <vgoyal@redhat.com>,
	overlayfs <linux-unionfs@vger.kernel.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH v3 2/4] ovl: relax WARN_ON() real inode attributes mismatch
Date: Wed, 16 May 2018 16:46:29 +0300	[thread overview]
Message-ID: <CAOQ4uxh4Ad3G3w+98hsdHaY=_9tBzm7w9jOgAtLk8r+RgZU8OA@mail.gmail.com> (raw)
In-Reply-To: <CAJfpegvJN_CDHcGw7sXbAgE_a3r0V5hC70COMuv6Z6o4yef=NA@mail.gmail.com>

On Wed, May 16, 2018 at 2:18 PM, Miklos Szeredi <miklos@szeredi.hu> wrote:
> On Wed, May 16, 2018 at 1:06 PM, Amir Goldstein <amir73il@gmail.com> wrote:
>> On Wed, May 16, 2018 at 1:29 PM, Miklos Szeredi <miklos@szeredi.hu> wrote:
>>> On Tue, May 15, 2018 at 12:26 PM, Amir Goldstein <amir73il@gmail.com> wrote:
>>>> Overlayfs should cope with online changes to underlying layer
>>>> without crashing the kernel, which is what xfstest overlay/019
>>>> checks.
>>>>
>>>> This test may sometimes trigger WARN_ON() in ovl_create_or_link()
>>>> when linking an overlay inode that has been changed on underlying
>>>> layer.
>>>>
>>>> Replace those WARN_ON() with pr_warn_ratelimited() to prevent
>>>> test from failing and because this is more appropriate to the
>>>> use case.
>>>>
>>>> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
>>>> ---
>>>>  fs/overlayfs/dir.c | 14 +++++++++++---
>>>>  1 file changed, 11 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
>>>> index 62e6733b755c..25b339278684 100644
>>>> --- a/fs/overlayfs/dir.c
>>>> +++ b/fs/overlayfs/dir.c
>>>> @@ -525,9 +525,17 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
>>>>         if (!err) {
>>>>                 struct inode *realinode = d_inode(ovl_dentry_upper(dentry));
>>>>
>>>> -               WARN_ON(inode->i_mode != realinode->i_mode);
>>>> -               WARN_ON(!uid_eq(inode->i_uid, realinode->i_uid));
>>>> -               WARN_ON(!gid_eq(inode->i_gid, realinode->i_gid));
>>>> +               if (inode->i_mode != realinode->i_mode ||
>>>> +                   !uid_eq(inode->i_uid, realinode->i_uid) ||
>>>> +                   !gid_eq(inode->i_gid, realinode->i_gid)) {
>>>> +                       pr_warn_ratelimited("overlayfs: real inode attributes mismatch (%pd2, %o.%u.%u != %o.%u.%u).\n",
>>>> +                               dentry, inode->i_mode,
>>>> +                               from_kuid(&init_user_ns, inode->i_uid),
>>>> +                               from_kgid(&init_user_ns, inode->i_gid),
>>>> +                               realinode->i_mode,
>>>> +                               from_kuid(&init_user_ns, realinode->i_uid),
>>>> +                               from_kgid(&init_user_ns, realinode->i_gid));
>>>> +               }
>>>
>>> How about just dropping the warnings altogether.  They didn't discover
>>> an issue with the code, just something normal, so IMO we should just
>>> get rid of them.
>>>
>>

I guess it would be wise to leave that check in at least for the case we end
up using a cached inode instead of the new inode we created...

Thanks,
Amir.

  reply	other threads:[~2018-05-16 13:46 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-15 10:26 [PATCH v3 0/4] Overlayfs mkdir related fixes Amir Goldstein
2018-05-15 10:26 ` [PATCH v3 1/4] ovl: use insert_inode_locked4() to hash a newly created inode Amir Goldstein
2018-05-15 13:23   ` Vivek Goyal
2018-05-15 13:37     ` Amir Goldstein
2018-05-16  8:34       ` Miklos Szeredi
2018-05-16  9:51         ` Amir Goldstein
2018-05-16 10:14           ` Miklos Szeredi
2018-05-16 11:03             ` Amir Goldstein
2018-05-17  6:03       ` Amir Goldstein
2018-05-17  8:10         ` Miklos Szeredi
2018-05-17  8:45           ` Amir Goldstein
2018-05-17  8:53           ` Miklos Szeredi
2018-05-17  8:58             ` Amir Goldstein
2018-05-17  9:07               ` Miklos Szeredi
2018-05-17 16:14                 ` Amir Goldstein
2018-05-15 10:26 ` [PATCH v3 2/4] ovl: relax WARN_ON() real inode attributes mismatch Amir Goldstein
2018-05-15 12:48   ` Vivek Goyal
2018-05-15 12:55     ` Amir Goldstein
2018-05-16 10:29   ` Miklos Szeredi
2018-05-16 11:06     ` Amir Goldstein
2018-05-16 11:18       ` Miklos Szeredi
2018-05-16 13:46         ` Amir Goldstein [this message]
2018-05-15 10:26 ` [PATCH v3 3/4] ovl: create helper ovl_create_temp() Amir Goldstein
2018-05-16 10:41   ` Miklos Szeredi
2018-05-16 11:15     ` Amir Goldstein
2018-05-16 11:37       ` Miklos Szeredi
2018-05-15 10:26 ` [PATCH v3 4/4] ovl: make ovl_create_real() cope with vfs_mkdir() safely Amir Goldstein

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAOQ4uxh4Ad3G3w+98hsdHaY=_9tBzm7w9jOgAtLk8r+RgZU8OA@mail.gmail.com' \
    --to=amir73il@gmail.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-unionfs@vger.kernel.org \
    --cc=miklos@szeredi.hu \
    --cc=vgoyal@redhat.com \
    --cc=viro@zeniv.linux.org.uk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).