Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link()

From	Adrian Hunter <adrian.hunter@intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link()
Date	2017-03-30 14:10 +0200
Message-ID	<tqH3P-65b-9@gated-at.bofh.it> (permalink)
References	<tqE5Y-3Mi-15@gated-at.bofh.it> <tqEIF-4h2-3@gated-at.bofh.it> <tqESm-4kQ-23@gated-at.bofh.it> <tqFv4-4UX-25@gated-at.bofh.it>
Organization	Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki

Show all headers | View raw

On 30/03/17 13:23, Richard Weinberger wrote:
> Am 30.03.2017 um 11:49 schrieb Richard Weinberger:
>> Am 30.03.2017 um 11:32 schrieb Adrian Hunter:
>>>> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
>>>> index 0858213a4e63..0139155045fe 100644
>>>> --- a/fs/ubifs/dir.c
>>>> +++ b/fs/ubifs/dir.c
>>>> @@ -748,6 +748,11 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
>>>>  		goto out_fname;
>>>>  
>>>>  	lock_2_inodes(dir, inode);
>>>> +
>>>> +	/* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */
>>>> +	if (inode->i_nlink == 0)
>>>> +		ubifs_delete_orphan(c, inode->i_ino);
>>>
>>> Isn't there also a deletion inode in the journal?  If the recovery sees that
>>> won't it delete the file data?
>>
>> Yes, but ubifs_link() adds a new journal entry which revives the inode.
>> This should cancel out the deletion, right?
>> You know the UBIFS journal better than I do. :-)
> 
> Reading deeper into the proved that I was wrong.
> AFAIKT UBIFS' journal has currently no way to revive a deleted inode.
> So, we have to think about a new solution.

Deleting the orphan looks right.  Just need to understand whether the
recovery would do the right thing - actually it looks like O_TMPFILE might
be OK and in other case we might be failing to remove nodes with sequence
numbers greater than the deletion inode.

Thread

[PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Richard Weinberger <richard@nod.at> - 2017-03-30 11:00 +0200
  Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Amir Goldstein <amir73il@gmail.com> - 2017-03-30 11:10 +0200
    Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Richard Weinberger <richard@nod.at> - 2017-03-30 11:20 +0200
  Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Amir Goldstein <amir73il@gmail.com> - 2017-03-30 11:10 +0200
    Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Richard Weinberger <richard@nod.at> - 2017-03-30 11:20 +0200
    Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Ralph Sennhauser <ralph.sennhauser@gmail.com> - 2017-03-30 11:20 +0200
  Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Adrian Hunter <adrian.hunter@intel.com> - 2017-03-30 11:40 +0200
    Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Richard Weinberger <richard@nod.at> - 2017-03-30 11:50 +0200
      Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Richard Weinberger <richard@nod.at> - 2017-03-30 12:30 +0200
        Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Amir Goldstein <amir73il@gmail.com> - 2017-03-30 12:40 +0200
          Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Richard Weinberger <richard@nod.at> - 2017-03-30 13:00 +0200
        Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Adrian Hunter <adrian.hunter@intel.com> - 2017-03-30 14:10 +0200
          Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Richard Weinberger <richard@nod.at> - 2017-03-30 14:30 +0200
            Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Richard Weinberger <richard@nod.at> - 2017-04-06 14:10 +0200
              Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Richard Weinberger <richard@nod.at> - 2017-04-06 14:30 +0200
            Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Amir Goldstein <amir73il@gmail.com> - 2017-04-06 14:10 +0200
  Re: [PATCH] ubifs: Fix O_TMPFILE corner case in ubifs_link() Hyunchul Lee <hyc.lee@gmail.com> - 2017-03-30 12:40 +0200

csiph-web