* [PATCH] xfs: remove use of do_div with 32-bit dividend in quota debug code
@ 2017-04-15 14:46 Eric Sandeen
2017-04-17 18:27 ` Bill O'Donnell
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Eric Sandeen @ 2017-04-15 14:46 UTC (permalink / raw)
To: linux-xfs
The kbuild test robot caught this; in debug code we have another
caller of do_div with a 32-bit dividend (j) which is caught now
that we are using the kernel-supplied do_div.
None of the values used here are 64-bit; just use simple division.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index b669b12..dedeb7f 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -851,8 +851,7 @@ struct xfs_qm_isolate {
* started afresh by xfs_qm_quotacheck.
*/
#ifdef DEBUG
- j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
- do_div(j, sizeof(xfs_dqblk_t));
+ j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB) / sizeof(xfs_dqblk_t);
ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
#endif
dqb = bp->b_addr;
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH] xfs: remove use of do_div with 32-bit dividend in quota debug code
2017-04-15 14:46 [PATCH] xfs: remove use of do_div with 32-bit dividend in quota debug code Eric Sandeen
@ 2017-04-17 18:27 ` Bill O'Donnell
2017-04-17 18:59 ` Darrick J. Wong
2017-04-19 19:41 ` [PATCH V2] " Eric Sandeen
2 siblings, 0 replies; 8+ messages in thread
From: Bill O'Donnell @ 2017-04-17 18:27 UTC (permalink / raw)
To: Eric Sandeen; +Cc: linux-xfs
On Sat, Apr 15, 2017 at 09:46:09AM -0500, Eric Sandeen wrote:
> The kbuild test robot caught this; in debug code we have another
> caller of do_div with a 32-bit dividend (j) which is caught now
> that we are using the kernel-supplied do_div.
>
> None of the values used here are 64-bit; just use simple division.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Looks good.
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
> ---
>
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index b669b12..dedeb7f 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -851,8 +851,7 @@ struct xfs_qm_isolate {
> * started afresh by xfs_qm_quotacheck.
> */
> #ifdef DEBUG
> - j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
> - do_div(j, sizeof(xfs_dqblk_t));
> + j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB) / sizeof(xfs_dqblk_t);
> ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
> #endif
> dqb = bp->b_addr;
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] xfs: remove use of do_div with 32-bit dividend in quota debug code
2017-04-15 14:46 [PATCH] xfs: remove use of do_div with 32-bit dividend in quota debug code Eric Sandeen
2017-04-17 18:27 ` Bill O'Donnell
@ 2017-04-17 18:59 ` Darrick J. Wong
2017-04-19 19:29 ` Eric Sandeen
2017-04-19 19:41 ` [PATCH V2] " Eric Sandeen
2 siblings, 1 reply; 8+ messages in thread
From: Darrick J. Wong @ 2017-04-17 18:59 UTC (permalink / raw)
To: Eric Sandeen; +Cc: linux-xfs
On Sat, Apr 15, 2017 at 09:46:09AM -0500, Eric Sandeen wrote:
> The kbuild test robot caught this; in debug code we have another
> caller of do_div with a 32-bit dividend (j) which is caught now
> that we are using the kernel-supplied do_div.
>
> None of the values used here are 64-bit; just use simple division.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
>
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index b669b12..dedeb7f 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -851,8 +851,7 @@ struct xfs_qm_isolate {
> * started afresh by xfs_qm_quotacheck.
> */
> #ifdef DEBUG
> - j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
> - do_div(j, sizeof(xfs_dqblk_t));
> + j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB) / sizeof(xfs_dqblk_t);
Uh...
#define XFS_FSB_TO_B(mp,fsbno) ((xfs_fsize_t)(fsbno) << (mp)->m_sb.sb_blocklog)
typedef __int64_t xfs_fsize_t; /* bytes in a file */
So the macro resolves to a 64-bit value, which is then fed directly into
an integer division, which breaks the i386 build with the usual __divdi3
complaint.
--D
> ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
> #endif
> dqb = bp->b_addr;
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] xfs: remove use of do_div with 32-bit dividend in quota debug code
2017-04-17 18:59 ` Darrick J. Wong
@ 2017-04-19 19:29 ` Eric Sandeen
0 siblings, 0 replies; 8+ messages in thread
From: Eric Sandeen @ 2017-04-19 19:29 UTC (permalink / raw)
To: Darrick J. Wong, Eric Sandeen; +Cc: linux-xfs
On 4/17/17 1:59 PM, Darrick J. Wong wrote:
> On Sat, Apr 15, 2017 at 09:46:09AM -0500, Eric Sandeen wrote:
>> The kbuild test robot caught this; in debug code we have another
>> caller of do_div with a 32-bit dividend (j) which is caught now
>> that we are using the kernel-supplied do_div.
>>
>> None of the values used here are 64-bit; just use simple division.
>>
>> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
>> ---
>>
>> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
>> index b669b12..dedeb7f 100644
>> --- a/fs/xfs/xfs_qm.c
>> +++ b/fs/xfs/xfs_qm.c
>> @@ -851,8 +851,7 @@ struct xfs_qm_isolate {
>> * started afresh by xfs_qm_quotacheck.
>> */
>> #ifdef DEBUG
>> - j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
>> - do_div(j, sizeof(xfs_dqblk_t));
>> + j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB) / sizeof(xfs_dqblk_t);
>
> Uh...
>
> #define XFS_FSB_TO_B(mp,fsbno) ((xfs_fsize_t)(fsbno) << (mp)->m_sb.sb_blocklog)
> typedef __int64_t xfs_fsize_t; /* bytes in a file */
Assigned to "int j", riiiiight. hohum.
> So the macro resolves to a 64-bit value, which is then fed directly into
> an integer division, which breaks the i386 build with the usual __divdi3
> complaint.
sandeen--
> --D
>
>> ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
>> #endif
>> dqb = bp->b_addr;
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH V2] xfs: remove use of do_div with 32-bit dividend in quota debug code
2017-04-15 14:46 [PATCH] xfs: remove use of do_div with 32-bit dividend in quota debug code Eric Sandeen
2017-04-17 18:27 ` Bill O'Donnell
2017-04-17 18:59 ` Darrick J. Wong
@ 2017-04-19 19:41 ` Eric Sandeen
2017-04-19 20:01 ` Darrick J. Wong
` (2 more replies)
2 siblings, 3 replies; 8+ messages in thread
From: Eric Sandeen @ 2017-04-19 19:41 UTC (permalink / raw)
To: Eric Sandeen, linux-xfs
The kbuild test robot caught this; in debug code we have another
caller of do_div with a 32-bit dividend (j) which is caught now
that we are using the kernel-supplied do_div.
None of the values used here are 64-bit; just use simple division.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
V2: now with less actual 64-bit division!
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index b669b12..6b42db4 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -851,8 +851,8 @@ struct xfs_qm_isolate {
* started afresh by xfs_qm_quotacheck.
*/
#ifdef DEBUG
- j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
- do_div(j, sizeof(xfs_dqblk_t));
+ j = (int)XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB) /
+ sizeof(xfs_dqblk_t);
ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
#endif
dqb = bp->b_addr;
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH V2] xfs: remove use of do_div with 32-bit dividend in quota debug code
2017-04-19 19:41 ` [PATCH V2] " Eric Sandeen
@ 2017-04-19 20:01 ` Darrick J. Wong
2017-04-19 20:21 ` Bill O'Donnell
2017-04-19 20:23 ` Bill O'Donnell
2 siblings, 0 replies; 8+ messages in thread
From: Darrick J. Wong @ 2017-04-19 20:01 UTC (permalink / raw)
To: Eric Sandeen; +Cc: Eric Sandeen, linux-xfs
On Wed, Apr 19, 2017 at 02:41:07PM -0500, Eric Sandeen wrote:
> The kbuild test robot caught this; in debug code we have another
> caller of do_div with a 32-bit dividend (j) which is caught now
> that we are using the kernel-supplied do_div.
>
> None of the values used here are 64-bit; just use simple division.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Looks ok, will throw it on the testing pile...
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
(Seems to build ok on i386 too.)
--D
> ---
>
> V2: now with less actual 64-bit division!
>
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index b669b12..6b42db4 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -851,8 +851,8 @@ struct xfs_qm_isolate {
> * started afresh by xfs_qm_quotacheck.
> */
> #ifdef DEBUG
> - j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
> - do_div(j, sizeof(xfs_dqblk_t));
> + j = (int)XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB) /
> + sizeof(xfs_dqblk_t);
> ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
> #endif
> dqb = bp->b_addr;
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH V2] xfs: remove use of do_div with 32-bit dividend in quota debug code
2017-04-19 19:41 ` [PATCH V2] " Eric Sandeen
2017-04-19 20:01 ` Darrick J. Wong
@ 2017-04-19 20:21 ` Bill O'Donnell
2017-04-19 20:23 ` Bill O'Donnell
2 siblings, 0 replies; 8+ messages in thread
From: Bill O'Donnell @ 2017-04-19 20:21 UTC (permalink / raw)
To: Eric Sandeen; +Cc: Eric Sandeen, linux-xfs
On Wed, Apr 19, 2017 at 02:41:07PM -0500, Eric Sandeen wrote:
> The kbuild test robot caught this; in debug code we have another
> caller of do_div with a 32-bit dividend (j) which is caught now
> that we are using the kernel-supplied do_div.
>
> None of the values used here are 64-bit; just use simple division.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
looks even better now ;)
Reviewed-by: Bill O'Donnell
> ---
>
> V2: now with less actual 64-bit division!
>
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index b669b12..6b42db4 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -851,8 +851,8 @@ struct xfs_qm_isolate {
> * started afresh by xfs_qm_quotacheck.
> */
> #ifdef DEBUG
> - j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
> - do_div(j, sizeof(xfs_dqblk_t));
> + j = (int)XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB) /
> + sizeof(xfs_dqblk_t);
> ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
> #endif
> dqb = bp->b_addr;
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH V2] xfs: remove use of do_div with 32-bit dividend in quota debug code
2017-04-19 19:41 ` [PATCH V2] " Eric Sandeen
2017-04-19 20:01 ` Darrick J. Wong
2017-04-19 20:21 ` Bill O'Donnell
@ 2017-04-19 20:23 ` Bill O'Donnell
2 siblings, 0 replies; 8+ messages in thread
From: Bill O'Donnell @ 2017-04-19 20:23 UTC (permalink / raw)
To: Eric Sandeen; +Cc: Eric Sandeen, linux-xfs
On Wed, Apr 19, 2017 at 02:41:07PM -0500, Eric Sandeen wrote:
> The kbuild test robot caught this; in debug code we have another
> caller of do_div with a 32-bit dividend (j) which is caught now
> that we are using the kernel-supplied do_div.
>
> None of the values used here are 64-bit; just use simple division.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
reviewed again, this time with proper email sig. ;)
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
> ---
>
> V2: now with less actual 64-bit division!
>
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index b669b12..6b42db4 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -851,8 +851,8 @@ struct xfs_qm_isolate {
> * started afresh by xfs_qm_quotacheck.
> */
> #ifdef DEBUG
> - j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
> - do_div(j, sizeof(xfs_dqblk_t));
> + j = (int)XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB) /
> + sizeof(xfs_dqblk_t);
> ASSERT(mp->m_quotainfo->qi_dqperchunk == j);
> #endif
> dqb = bp->b_addr;
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2017-04-19 20:23 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-04-15 14:46 [PATCH] xfs: remove use of do_div with 32-bit dividend in quota debug code Eric Sandeen
2017-04-17 18:27 ` Bill O'Donnell
2017-04-17 18:59 ` Darrick J. Wong
2017-04-19 19:29 ` Eric Sandeen
2017-04-19 19:41 ` [PATCH V2] " Eric Sandeen
2017-04-19 20:01 ` Darrick J. Wong
2017-04-19 20:21 ` Bill O'Donnell
2017-04-19 20:23 ` Bill O'Donnell
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