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        Mon, 16 Jan 2017 10:46:47 -0500
From: Jan Stancek <jstancek@redhat.com>
Subject: utimensat EACCES vs. EPERM in 4.8+
To: linux-fsdevel@vger.kernel.org
Cc: jstancek@redhat.com, viro@ZenIV.linux.org.uk, guaneryu@gmail.com,
        mszeredi@redhat.com, Cyril Hrubis <chrubis@suse.cz>,
        ltp@lists.linux.it, mtk.manpages@gmail.com
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Date: Mon, 16 Jan 2017 16:46:45 +0100
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Hi,

we seem to have a conflict between kernel and man pages.
>>From utimensat man page:

EACCES times is NULL, or both tv_nsec values are UTIME_NOW, and either:
       *  the effective user ID of the caller does not match the owner of the
          file, the caller does not  have  write  access  to  the file, and the
          caller is not privileged (Linux: does not have either the CAP_FOWNER
          or the CAP_DAC_OVERRIDE capability); or,
       *  the file is marked immutable (see chattr(1)).

But following 2 commits gradually replaced EACCES with EPERM.

commit 337684a1746f93ae107e05d90977b070bb7e39d8
Author: Eryu Guan <guaneryu@gmail.com>
Date:   Tue Aug 2 19:58:28 2016 +0800
    fs: return EPERM on immutable inode

commit f2b20f6ee842313a0d681dbbf7f87b70291a6a3b
Author: Miklos Szeredi <mszeredi@redhat.com>
Date:   Fri Sep 16 12:44:20 2016 +0200
    vfs: move permission checking into notify_change() for utimes(NULL)

4.9 kernel and simple touch on immutable file gives me:
utimensat(AT_FDCWD, "afile", NULL, 0)   = -1 EPERM (Operation not permitted)

while an older kernel it gives me:
utimensat(AT_FDCWD, "afile", NULL, 0)   = -1 EACCES (Permission denied)

Do we need to update man page or fix kernel back to return EACCES?

Thanks,
Jan

From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jan Stancek <jstancek@redhat.com>
Date: Mon, 16 Jan 2017 16:46:45 +0100
Subject: [LTP] utimensat EACCES vs. EPERM in 4.8+
Message-ID: <18a5b416-ad6a-e679-d993-af7ffa0dcc10@redhat.com>
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To: ltp@lists.linux.it

Hi,

we seem to have a conflict between kernel and man pages.
>From utimensat man page:

EACCES times is NULL, or both tv_nsec values are UTIME_NOW, and either:
       *  the effective user ID of the caller does not match the owner of the
          file, the caller does not  have  write  access  to  the file, and the
          caller is not privileged (Linux: does not have either the CAP_FOWNER
          or the CAP_DAC_OVERRIDE capability); or,
       *  the file is marked immutable (see chattr(1)).

But following 2 commits gradually replaced EACCES with EPERM.

commit 337684a1746f93ae107e05d90977b070bb7e39d8
Author: Eryu Guan <guaneryu@gmail.com>
Date:   Tue Aug 2 19:58:28 2016 +0800
    fs: return EPERM on immutable inode

commit f2b20f6ee842313a0d681dbbf7f87b70291a6a3b
Author: Miklos Szeredi <mszeredi@redhat.com>
Date:   Fri Sep 16 12:44:20 2016 +0200
    vfs: move permission checking into notify_change() for utimes(NULL)

4.9 kernel and simple touch on immutable file gives me:
utimensat(AT_FDCWD, "afile", NULL, 0)   = -1 EPERM (Operation not permitted)

while an older kernel it gives me:
utimensat(AT_FDCWD, "afile", NULL, 0)   = -1 EACCES (Permission denied)

Do we need to update man page or fix kernel back to return EACCES?

Thanks,
Jan