From: Deepa Dinamani <deepa.kernel@gmail.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux FS-devel Mailing List <linux-fsdevel@vger.kernel.org>,
y2038 Mailman List <y2038@lists.linaro.org>,
Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH v8 08/20] adfs: Fill in max and min timestamps in sb
Date: Tue, 20 Aug 2019 16:55:44 -0700 [thread overview]
Message-ID: <CABeXuvoLHW2fYSNVC=N9tfNRtuq8Xg3QmqfcfMJEsCN5rEvuog@mail.gmail.com> (raw)
In-Reply-To: <20190820162856.GA21274@bombadil.infradead.org>
On Tue, Aug 20, 2019 at 9:28 AM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Sun, Aug 18, 2019 at 09:58:05AM -0700, Deepa Dinamani wrote:
> > Note that the min timestamp is assumed to be
> > 01 Jan 1970 00:00:00 (Unix epoch). This is consistent
> > with the way we convert timestamps in adfs_adfs2unix_time().
>
> That's not actually correct. RISC OS timestamps are centiseconds since
> 1900 stored in 5 bytes.
The timestamp can hold earlier values but the fs implementation
explicitly rejects those in adfs_adfs2unix_time() too_early check.
We could fix the implementation to not throw away times before 1970.
Are you suggesting we want to do this?
I could post a separate patch to fix this or we could do it as part of
the series.
static void
adfs_adfs2unix_time(struct timespec64 *tv, struct inode *inode)
{
unsigned int high, low;
static const s64 nsec_unix_epoch_diff_risc_os_epoch =
RISC_OS_EPOCH_DELTA * NSEC_PER_SEC;
s64 nsec;
if (!adfs_inode_is_stamped(inode))
goto cur_time;
high = ADFS_I(inode)->loadaddr & 0xFF; /* top 8 bits of timestamp */
low = ADFS_I(inode)->execaddr; /* bottom 32 bits of timestamp */
/* convert 40-bit centi-seconds to 32-bit seconds
* going via nanoseconds to retain precision
*/
nsec = (((s64) high << 32) | (s64) low) * 10000000; /* cs to ns */
/* Files dated pre 01 Jan 1970 00:00:00. */
if (nsec < nsec_unix_epoch_diff_risc_os_epoch)
goto too_early;
/* convert from RISC OS to Unix epoch */
nsec -= nsec_unix_epoch_diff_risc_os_epoch;
*tv = ns_to_timespec64(nsec);
return;
cur_time:
*tv = current_time(inode);
return;
too_early:
tv->tv_sec = tv->tv_nsec = 0;
return;
}
-Deepa
next prev parent reply other threads:[~2019-08-20 23:56 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-18 16:57 [PATCH v8 00/20] vfs: Add support for timestamp limits Deepa Dinamani
2019-08-18 16:57 ` [PATCH v8 01/20] vfs: Add file timestamp range support Deepa Dinamani
2019-08-18 16:57 ` [PATCH v8 02/20] vfs: Add timestamp_truncate() api Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 03/20] timestamp_truncate: Replace users of timespec64_trunc Deepa Dinamani
2019-08-18 18:34 ` Greg KH
2019-08-18 16:58 ` [PATCH v8 04/20] mount: Add mount warning for impending timestamp expiry Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 05/20] utimes: Clamp the timestamps before update Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 06/20] fs: Fill in max and min timestamps in superblock Deepa Dinamani
2019-08-20 11:28 ` Anders Larsen
[not found] ` <CAK+_RLmK0Vy79giAZnUCmmivvRT+GLZXyiMqBoFB0_Ed1W8BkA@mail.gmail.com>
2019-08-20 12:28 ` Tigran Aivazian
2019-08-18 16:58 ` [PATCH v8 07/20] 9p: Fill min and max timestamps in sb Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 08/20] adfs: Fill in max and min " Deepa Dinamani
2019-08-20 16:28 ` Matthew Wilcox
2019-08-20 23:55 ` Deepa Dinamani [this message]
2019-08-18 16:58 ` [PATCH v8 09/20] ext4: Initialize timestamps limits Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 10/20] fs: nfs: Initialize filesystem timestamp ranges Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 11/20] fs: cifs: " Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 12/20] fs: fat: " Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 13/20] fs: affs: " Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 14/20] fs: sysv: " Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 15/20] fs: ceph: " Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 16/20] fs: orangefs: " Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 17/20] fs: hpfs: " Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 18/20] fs: omfs: " Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 19/20] pstore: fs superblock limits Deepa Dinamani
2019-08-20 7:20 ` Kees Cook
2019-08-21 0:03 ` Deepa Dinamani
2019-08-18 16:58 ` [PATCH v8 20/20] isofs: Initialize filesystem timestamp ranges Deepa Dinamani
2019-08-20 11:05 ` [PATCH v8 00/20] vfs: Add support for timestamp limits Jeff Layton
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