[v2,09/24] quota: avoid time_t in v1_disk_dqblk definition

Message ID 20191213205221.3787308-6-arnd@arndb.de
State Accepted
Commit 1ead083ae1472e5aaee7f18ea827b13f55bd10a6
Headers show
Series
  • drivers, fs: y2038 updates
Related show

Commit Message

Arnd Bergmann Dec. 13, 2019, 8:52 p.m.
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>

---
 fs/quota/quotaio_v1.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

-- 
2.20.0

Comments

Jan Kara Dec. 16, 2019, 1:14 p.m. | #1
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

Patch

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)))