* [PATCH] xfs: avoid harmless gcc-7 warnings
@ 2017-05-11 12:49 Arnd Bergmann
2017-05-11 13:33 ` Eric Sandeen
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Arnd Bergmann @ 2017-05-11 12:49 UTC (permalink / raw)
To: Darrick J. Wong, linux-xfs
Cc: Arnd Bergmann, Dave Chinner, Brian Foster, Eric Sandeen,
Calvin Owens, linux-kernel
gcc-7 flags the use of integer math inside of a condition
as a potential bug:
fs/xfs/xfs_bmap_util.c: In function 'xfs_swap_extents_check_format':
fs/xfs/xfs_bmap_util.c:1619:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
fs/xfs/xfs_bmap_util.c:1629:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
This one is clearly fine, and we can add a comparison to zero
to shut up the warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
fs/xfs/xfs_bmap_util.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 2b954308a1d6..cbd3ffe42f39 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1613,7 +1613,7 @@ xfs_swap_extents_check_format(
* extent format...
*/
if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
- if (XFS_IFORK_BOFF(ip) &&
+ if ((XFS_IFORK_BOFF(ip) != 0) &&
XFS_BMAP_BMDR_SPACE(tip->i_df.if_broot) > XFS_IFORK_BOFF(ip))
return -EINVAL;
if (XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <=
@@ -1623,7 +1623,7 @@ xfs_swap_extents_check_format(
/* Reciprocal target->temp btree format checks */
if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
- if (XFS_IFORK_BOFF(tip) &&
+ if ((XFS_IFORK_BOFF(tip) != 0) &&
XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > XFS_IFORK_BOFF(tip))
return -EINVAL;
if (XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <=
--
2.9.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] xfs: avoid harmless gcc-7 warnings
2017-05-11 12:49 [PATCH] xfs: avoid harmless gcc-7 warnings Arnd Bergmann
@ 2017-05-11 13:33 ` Eric Sandeen
2017-05-11 14:02 ` Christoph Hellwig
2017-05-12 14:18 ` Joe Perches
2 siblings, 0 replies; 5+ messages in thread
From: Eric Sandeen @ 2017-05-11 13:33 UTC (permalink / raw)
To: Arnd Bergmann, Darrick J. Wong, linux-xfs
Cc: Dave Chinner, Brian Foster, Calvin Owens, linux-kernel
On 5/11/17 7:49 AM, Arnd Bergmann wrote:
> gcc-7 flags the use of integer math inside of a condition
> as a potential bug:
>
> fs/xfs/xfs_bmap_util.c: In function 'xfs_swap_extents_check_format':
> fs/xfs/xfs_bmap_util.c:1619:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
> fs/xfs/xfs_bmap_util.c:1629:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
>
> This one is clearly fine, and we can add a comparison to zero
> to shut up the warning.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Thanks Arnd -
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
> ---
> fs/xfs/xfs_bmap_util.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
> index 2b954308a1d6..cbd3ffe42f39 100644
> --- a/fs/xfs/xfs_bmap_util.c
> +++ b/fs/xfs/xfs_bmap_util.c
> @@ -1613,7 +1613,7 @@ xfs_swap_extents_check_format(
> * extent format...
> */
> if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
> - if (XFS_IFORK_BOFF(ip) &&
> + if ((XFS_IFORK_BOFF(ip) != 0) &&
> XFS_BMAP_BMDR_SPACE(tip->i_df.if_broot) > XFS_IFORK_BOFF(ip))
> return -EINVAL;
> if (XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <=
> @@ -1623,7 +1623,7 @@ xfs_swap_extents_check_format(
>
> /* Reciprocal target->temp btree format checks */
> if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
> - if (XFS_IFORK_BOFF(tip) &&
> + if ((XFS_IFORK_BOFF(tip) != 0) &&
> XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > XFS_IFORK_BOFF(tip))
> return -EINVAL;
> if (XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <=
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] xfs: avoid harmless gcc-7 warnings
2017-05-11 12:49 [PATCH] xfs: avoid harmless gcc-7 warnings Arnd Bergmann
2017-05-11 13:33 ` Eric Sandeen
@ 2017-05-11 14:02 ` Christoph Hellwig
2017-05-11 14:56 ` Arnd Bergmann
2017-05-12 14:18 ` Joe Perches
2 siblings, 1 reply; 5+ messages in thread
From: Christoph Hellwig @ 2017-05-11 14:02 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Darrick J. Wong, linux-xfs, Dave Chinner, Brian Foster,
Eric Sandeen, Calvin Owens, linux-kernel
On Thu, May 11, 2017 at 02:49:21PM +0200, Arnd Bergmann wrote:
> gcc-7 flags the use of integer math inside of a condition
> as a potential bug:
>
> fs/xfs/xfs_bmap_util.c: In function 'xfs_swap_extents_check_format':
> fs/xfs/xfs_bmap_util.c:1619:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
> fs/xfs/xfs_bmap_util.c:1629:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
>
> This one is clearly fine, and we can add a comparison to zero
> to shut up the warning.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> fs/xfs/xfs_bmap_util.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
> index 2b954308a1d6..cbd3ffe42f39 100644
> --- a/fs/xfs/xfs_bmap_util.c
> +++ b/fs/xfs/xfs_bmap_util.c
> @@ -1613,7 +1613,7 @@ xfs_swap_extents_check_format(
> * extent format...
> */
> if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
> - if (XFS_IFORK_BOFF(ip) &&
> + if ((XFS_IFORK_BOFF(ip) != 0) &&
Even if we were fine with fixing this odd warning the additional braces
are simply bogus.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] xfs: avoid harmless gcc-7 warnings
2017-05-11 14:02 ` Christoph Hellwig
@ 2017-05-11 14:56 ` Arnd Bergmann
0 siblings, 0 replies; 5+ messages in thread
From: Arnd Bergmann @ 2017-05-11 14:56 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Darrick J. Wong, linux-xfs, Dave Chinner, Brian Foster,
Eric Sandeen, Calvin Owens, Linux Kernel Mailing List
On Thu, May 11, 2017 at 4:02 PM, Christoph Hellwig <hch@infradead.org> wrote:
> On Thu, May 11, 2017 at 02:49:21PM +0200, Arnd Bergmann wrote:
>> gcc-7 flags the use of integer math inside of a condition
>> as a potential bug:
>>
>> fs/xfs/xfs_bmap_util.c: In function 'xfs_swap_extents_check_format':
>> fs/xfs/xfs_bmap_util.c:1619:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
>> fs/xfs/xfs_bmap_util.c:1629:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
>>
>> This one is clearly fine, and we can add a comparison to zero
>> to shut up the warning.
>>
>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>> ---
>> fs/xfs/xfs_bmap_util.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
>> index 2b954308a1d6..cbd3ffe42f39 100644
>> --- a/fs/xfs/xfs_bmap_util.c
>> +++ b/fs/xfs/xfs_bmap_util.c
>> @@ -1613,7 +1613,7 @@ xfs_swap_extents_check_format(
>> * extent format...
>> */
>> if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
>> - if (XFS_IFORK_BOFF(ip) &&
>> + if ((XFS_IFORK_BOFF(ip) != 0) &&
>
> Even if we were fine with fixing this odd warning the additional braces
> are simply bogus.
The warning seems generally useful and is enabled by default in gcc-7.
An example of a real bug it found is
https://patchwork.kernel.org/patch/9431813/, so I'd prefer to leave it
enabled and fix the few instances in the kernel.
I found a better way to rework the code to avoid the warning, sending
out v2 now.
Arnd
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] xfs: avoid harmless gcc-7 warnings
2017-05-11 12:49 [PATCH] xfs: avoid harmless gcc-7 warnings Arnd Bergmann
2017-05-11 13:33 ` Eric Sandeen
2017-05-11 14:02 ` Christoph Hellwig
@ 2017-05-12 14:18 ` Joe Perches
2 siblings, 0 replies; 5+ messages in thread
From: Joe Perches @ 2017-05-12 14:18 UTC (permalink / raw)
To: Arnd Bergmann, Darrick J. Wong, linux-xfs
Cc: Dave Chinner, Brian Foster, Eric Sandeen, Calvin Owens,
linux-kernel
On Thu, 2017-05-11 at 14:49 +0200, Arnd Bergmann wrote:
> gcc-7 flags the use of integer math inside of a condition
> as a potential bug:
>
> fs/xfs/xfs_bmap_util.c: In function 'xfs_swap_extents_check_format':
> fs/xfs/xfs_bmap_util.c:1619:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
> fs/xfs/xfs_bmap_util.c:1629:8: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]
>
> This one is clearly fine, and we can add a comparison to zero
> to shut up the warning.
[]
> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
[]
> @@ -1613,7 +1613,7 @@ xfs_swap_extents_check_format(
> * extent format...
> */
> if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
> - if (XFS_IFORK_BOFF(ip) &&
> + if ((XFS_IFORK_BOFF(ip) != 0) &&
As far as I can tell, this suggestion makes no sense.
$ git grep -E "define\s+XFS_IFORK_BOFF"
fs/xfs/libxfs/xfs_inode_fork.h:#define XFS_IFORK_BOFF(ip) ((int)((ip)->i_d.di_forkoff << 3))
$ git grep -w di_forkoff|grep -P "\w+\s+di_forkoff\s*;"
fs/xfs/libxfs/xfs_format.h: __u8 di_forkoff; /* attr fork offs, <<3 for 64b align */
fs/xfs/libxfs/xfs_inode_buf.h: __uint8_t di_forkoff; /* attr fork offs, <<3 for 64b align */
fs/xfs/libxfs/xfs_log_format.h: __uint8_t di_forkoff; /* attr fork offs, <<3 for 64b align */
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-05-11 12:49 [PATCH] xfs: avoid harmless gcc-7 warnings Arnd Bergmann
2017-05-11 13:33 ` Eric Sandeen
2017-05-11 14:02 ` Christoph Hellwig
2017-05-11 14:56 ` Arnd Bergmann
2017-05-12 14:18 ` Joe Perches
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