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SubjectRe: [PATCH v2 09/24] quota: avoid time_t in v1_disk_dqblk definition
On Fri 13-12-19 21:52:14, Arnd Bergmann wrote:
> The time_t type is part of the user interface and not always the
> same, with the move to 64-bit timestamps and the difference between
> architectures.
>
> Make the quota format definition independent of this type and use
> a basic type of the same length. Make it unsigned in the process
> to keep the v1 format working until year 2106 instead of 2038
> on 32-bit architectures.
>
> Hopefully, everybody has already moved to a newer format long
> ago (v2 was introduced with linux-2.4), but it's hard to be sure.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

What's worse, time_t is actually a part of on-disk format for this ancient
quota format making format incompatible between 32-bit and 64-bit
systems... Anyway, your patch looks good, I'll add it to my tree (speak up
if you want to merge it yourself due to something depending on it).

Honza

> ---
> fs/quota/quotaio_v1.h | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/fs/quota/quotaio_v1.h b/fs/quota/quotaio_v1.h
> index bd11e2c08119..31dca9a89176 100644
> --- a/fs/quota/quotaio_v1.h
> +++ b/fs/quota/quotaio_v1.h
> @@ -25,8 +25,10 @@ struct v1_disk_dqblk {
> __u32 dqb_ihardlimit; /* absolute limit on allocated inodes */
> __u32 dqb_isoftlimit; /* preferred inode limit */
> __u32 dqb_curinodes; /* current # allocated inodes */
> - time_t dqb_btime; /* time limit for excessive disk use */
> - time_t dqb_itime; /* time limit for excessive inode use */
> +
> + /* below fields differ in length on 32-bit vs 64-bit architectures */
> + unsigned long dqb_btime; /* time limit for excessive disk use */
> + unsigned long dqb_itime; /* time limit for excessive inode use */
> };
>
> #define v1_dqoff(UID) ((loff_t)((UID) * sizeof (struct v1_disk_dqblk)))
> --
> 2.20.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR

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