linux-next: build warning after merge of the btrfs-kdave tree

linux-next: build warning after merge of the btrfs-kdave tree

[Stephen Rothwell]

Hi David,

After merging the btrfs-kdave tree, today's linux-next build (powerpc
ppc64_defconfig) produced this warning:

fs/btrfs/inode.c: In function 'run_delalloc_range':
fs/btrfs/inode.c:1219:9: warning: 'cur_end' may be used uninitialized in this function [-Wmaybe-uninitialized]
   start = cur_end + 1;
         ^
fs/btrfs/inode.c:1172:6: note: 'cur_end' was declared here
  u64 cur_end;
      ^

Introduced by commit

  cow_file_range_async ("btrfs: Introduce COMPRESS reserve type to fix false enospc for compression")

Presumably a false positive because ASSERT(0) panics?

-- 
Cheers,
Stephen Rothwell

Re: linux-next: build warning after merge of the btrfs-kdave tree

[Stephen Rothwell]

Hi David,

On Mon, 28 Nov 2016 11:02:30 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> After merging the btrfs-kdave tree, today's linux-next build (powerpc
> ppc64_defconfig) produced this warning:
> 
> fs/btrfs/inode.c: In function 'run_delalloc_range':
> fs/btrfs/inode.c:1219:9: warning: 'cur_end' may be used uninitialized in this function [-Wmaybe-uninitialized]
>    start = cur_end + 1;
>          ^
> fs/btrfs/inode.c:1172:6: note: 'cur_end' was declared here
>   u64 cur_end;
>       ^
> 
> Introduced by commit
> 
>   cow_file_range_async ("btrfs: Introduce COMPRESS reserve type to fix false enospc for compression")
> 
> Presumably a false positive because ASSERT(0) panics?

Actually it does not if CONFIG_BTRFS_ASSERT is not set (which it isn't
for the above build), so this is not a false positive.  I am still
seeing this.

-- 
Cheers,
Stephen Rothwell

Re: linux-next: build warning after merge of the btrfs-kdave tree

[David Sterba]

On Wed, Dec 07, 2016 at 09:38:19AM +1100, Stephen Rothwell wrote:
> Hi David,
> 
> On Mon, 28 Nov 2016 11:02:30 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > After merging the btrfs-kdave tree, today's linux-next build (powerpc
> > ppc64_defconfig) produced this warning:
> > 
> > fs/btrfs/inode.c: In function 'run_delalloc_range':
> > fs/btrfs/inode.c:1219:9: warning: 'cur_end' may be used uninitialized in this function [-Wmaybe-uninitialized]
> >    start = cur_end + 1;
> >          ^
> > fs/btrfs/inode.c:1172:6: note: 'cur_end' was declared here
> >   u64 cur_end;
> >       ^
> > 
> > Introduced by commit
> > 
> >   cow_file_range_async ("btrfs: Introduce COMPRESS reserve type to fix false enospc for compression")
> > 
> > Presumably a false positive because ASSERT(0) panics?
> 
> Actually it does not if CONFIG_BTRFS_ASSERT is not set (which it isn't
> for the above build), so this is not a false positive.  I am still
> seeing this.

Sorry for late reply. I've updatd the for-next branch now, the patches
introducing the warning have been removed temporarily. Arnd Bergmann
sent a patch to fix the warning, I'll make sure to include it so the
warning does not reappear.

Re: linux-next: build warning after merge of the btrfs-kdave tree

[David Sterba]

On Fri, May 03, 2019 at 10:21:05AM +1000, Stephen Rothwell wrote:
> Hi David,
> 
> After merging the btrfs-kdave tree, today's linux-next build (x86_64
> allmodconfig) produced this warning:
> 
> fs/btrfs/props.c: In function 'inherit_props':
> fs/btrfs/props.c:389:4: warning: 'num_bytes' may be used uninitialized in this function [-Wmaybe-uninitialized]
>     btrfs_block_rsv_release(fs_info, trans->block_rsv,
>     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>       num_bytes);
>       ~~~~~~~~~~
> 
> Probably introduced by commit
> 
>   b835a4a3faec ("btrfs: use the existing reserved items for our first prop for inheritance")
> 
> Looks like a false positive to me.

Agreed and gcc 8.3.1 does not report that. Kbuild bot reported that as
well and it uses 7.x.

linux-next: build warning after merge of the btrfs-kdave tree

[Stephen Rothwell]

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Hi David,

After merging the btrfs-kdave tree, today's linux-next build (x86_64
allmodconfig) produced this warning:

fs/btrfs/props.c: In function 'inherit_props':
fs/btrfs/props.c:389:4: warning: 'num_bytes' may be used uninitialized in this function [-Wmaybe-uninitialized]
    btrfs_block_rsv_release(fs_info, trans->block_rsv,
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      num_bytes);
      ~~~~~~~~~~

Probably introduced by commit

  b835a4a3faec ("btrfs: use the existing reserved items for our first prop for inheritance")

Looks like a false positive to me.

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the btrfs-kdave tree

[David Sterba]

On Thu, Jan 24, 2019 at 09:53:38AM +1100, Stephen Rothwell wrote:
> Hi David,
> 
> After merging the btrfs-kdave tree, today's linux-next build (powerpc
> ppc64_defconfig) produced this warning:
> 
> fs/btrfs/relocation.c: In function 'insert_dirty_subv':
> fs/btrfs/relocation.c:2138:6: warning: unused variable 'root_objectid' [-Wunused-variable]
>   u64 root_objectid = root->root_key.objectid;
>       ^~~~~~~~~~~~~
> 
> Introduced by commit
> 
>   7b837199c581 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots()")
> 
> Presumably the ASSERT is compiled out in this configuration.

Agreed, thanks for the report. I'll drop the temporary variable.

linux-next: build warning after merge of the btrfs-kdave tree

[Stephen Rothwell]

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Hi David,

After merging the btrfs-kdave tree, today's linux-next build (powerpc
ppc64_defconfig) produced this warning:

fs/btrfs/relocation.c: In function 'insert_dirty_subv':
fs/btrfs/relocation.c:2138:6: warning: unused variable 'root_objectid' [-Wunused-variable]
  u64 root_objectid = root->root_key.objectid;
      ^~~~~~~~~~~~~

Introduced by commit

  7b837199c581 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots()")

Presumably the ASSERT is compiled out in this configuration.

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the btrfs-kdave tree

[Christoph Hellwig]

On Mon, Nov 26, 2018 at 11:06:29AM +1100, Stephen Rothwell wrote:
> Introduced by commit
> 
>   cf8cddd38bab3 ("btrfs: don't abuse REQ_OP_* flags for btrfs_map_block")
> 
> exposed by my new use of -Wimplicit-fallthrough
> 
> I am not sure why this has only turned up now (as opposed to earlier
> today).

It looks like something only in linux-next moved the code around a bit.

Either way the fallthough looks fine, it will just need a little
/*FALLTHRU*/ annotation.

linux-next: build warning after merge of the btrfs-kdave tree

[Stephen Rothwell]

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Hi David,

After merging the btrfs-kdave tree, today's linux-next build (powerpc
ppc64_defconfig) produced this warning:

In file included from include/linux/string.h:6,
                 from arch/powerpc/include/asm/paca.h:19,
                 from arch/powerpc/include/asm/current.h:16,
                 from include/linux/sched.h:12,
                 from fs/btrfs/volumes.c:6:
fs/btrfs/volumes.h: In function 'btrfs_op':
include/linux/compiler.h:77:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
 # define unlikely(x) __builtin_expect(!!(x), 0)
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
include/asm-generic/bug.h:72:2: note: in expansion of macro 'unlikely'
  unlikely(__ret_warn_on);    \
  ^~~~~~~~
fs/btrfs/volumes.h:395:3: note: in expansion of macro 'WARN_ON_ONCE'
   WARN_ON_ONCE(1);
   ^~~~~~~~~~~~
In file included from fs/btrfs/volumes.c:22:
fs/btrfs/volumes.h:396:2: note: here
  case REQ_OP_READ:
  ^~~~

Introduced by commit

  cf8cddd38bab3 ("btrfs: don't abuse REQ_OP_* flags for btrfs_map_block")

exposed by my new use of -Wimplicit-fallthrough

I am not sure why this has only turned up now (as opposed to earlier
today).

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the btrfs-kdave tree

[Qu Wenruo]

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On 2017年12月22日 00:49, David Sterba wrote:
> On Wed, Dec 20, 2017 at 08:12:11AM +0800, Qu Wenruo wrote:
>> On 2017年12月20日 06:20, Stephen Rothwell wrote:
>>> After merging the btrfs-kdave tree, today's linux-next build (powerpc
>>> ppc64_defconfig) produced this warning:
>>>
>>> fs/btrfs/qgroup.c: In function 'qgroup_reserve':
>>> fs/btrfs/qgroup.c:2432:1: warning: label 'retry' defined but not used [-Wunused-label]
>>>  retry:
>>>  ^
>>>
>>> Introduced by commit
>>>
>>>   b283738ab0ad ("Revert "btrfs: qgroups: Retry after commit on getting EDQUOT"")
>>>
>> Sorry, I forgot to clean it up.
>>
>> I'll update the patchset along with new patches to handle qgroup limit
>> better.
> 
> Meanwhile I've applied the fix from Arnd to silence the warning in
> linux-next builds.
> 

Some (not much, may be 2 or 3) patches is going to be updated:

btrfs: delayed-inode: Use new qgroup meta rsv for delayed inode and item
Revert "btrfs: qgroups: Retry after commit on getting EDQUOT" ( For the
lable)

And with 2 more new patches.

Do I need to resend the patchset or use separate patches for them?

Thanks,
Qu


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Re: linux-next: build warning after merge of the btrfs-kdave tree

[David Sterba]

On Wed, Dec 20, 2017 at 08:12:11AM +0800, Qu Wenruo wrote:
> On 2017年12月20日 06:20, Stephen Rothwell wrote:
> > After merging the btrfs-kdave tree, today's linux-next build (powerpc
> > ppc64_defconfig) produced this warning:
> > 
> > fs/btrfs/qgroup.c: In function 'qgroup_reserve':
> > fs/btrfs/qgroup.c:2432:1: warning: label 'retry' defined but not used [-Wunused-label]
> >  retry:
> >  ^
> > 
> > Introduced by commit
> > 
> >   b283738ab0ad ("Revert "btrfs: qgroups: Retry after commit on getting EDQUOT"")
> > 
> Sorry, I forgot to clean it up.
> 
> I'll update the patchset along with new patches to handle qgroup limit
> better.

Meanwhile I've applied the fix from Arnd to silence the warning in
linux-next builds.

Re: linux-next: build warning after merge of the btrfs-kdave tree

[Qu Wenruo]

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On 2017年12月20日 06:20, Stephen Rothwell wrote:
> Hi David,
> 
> After merging the btrfs-kdave tree, today's linux-next build (powerpc
> ppc64_defconfig) produced this warning:
> 
> fs/btrfs/qgroup.c: In function 'qgroup_reserve':
> fs/btrfs/qgroup.c:2432:1: warning: label 'retry' defined but not used [-Wunused-label]
>  retry:
>  ^
> 
> Introduced by commit
> 
>   b283738ab0ad ("Revert "btrfs: qgroups: Retry after commit on getting EDQUOT"")
> 
Sorry, I forgot to clean it up.

I'll update the patchset along with new patches to handle qgroup limit
better.

Thanks,
Qu


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linux-next: build warning after merge of the btrfs-kdave tree

[Stephen Rothwell]

Hi David,

After merging the btrfs-kdave tree, today's linux-next build (powerpc
ppc64_defconfig) produced this warning:

fs/btrfs/qgroup.c: In function 'qgroup_reserve':
fs/btrfs/qgroup.c:2432:1: warning: label 'retry' defined but not used [-Wunused-label]
 retry:
 ^

Introduced by commit

  b283738ab0ad ("Revert "btrfs: qgroups: Retry after commit on getting EDQUOT"")

-- 
Cheers,
Stephen Rothwell

Re: linux-next: build warning after merge of the btrfs-kdave tree

[Stephen Rothwell]

Hi David,

On Thu, 18 May 2017 14:50:00 +0200 David Sterba <dsterba@suse.cz> wrote:
>
> On Thu, May 18, 2017 at 09:41:46AM +1000, Stephen Rothwell wrote:
> > Hi David,
> > 
> > After merging the btrfs-kdave tree, today's linux-next build (powerpc
> > ppc64_defconfig) produced this warning:
> > 
> > fs/btrfs/inode.c: In function 'btrfs_submit_direct':
> > fs/btrfs/inode.c:8467:14: warning: 'bio' may be used uninitialized in this function [-Wmaybe-uninitialized]
> >   struct bio *bio;
> >               ^
> > 
> > I can't tell if it is a false positive or not.  
> 
> It seems to be a false positive. Patch updated and will be part of the
> next for-next.

I am still getting this.  Just checking that you didn't forget to push.

-- 
Cheers,
Stephen Rothwell

Re: linux-next: build warning after merge of the btrfs-kdave tree

[David Sterba]

On Thu, May 18, 2017 at 09:41:46AM +1000, Stephen Rothwell wrote:
> Hi David,
> 
> After merging the btrfs-kdave tree, today's linux-next build (powerpc
> ppc64_defconfig) produced this warning:
> 
> fs/btrfs/inode.c: In function 'btrfs_submit_direct':
> fs/btrfs/inode.c:8467:14: warning: 'bio' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   struct bio *bio;
>               ^
> 
> I can't tell if it is a false positive or not.

It seems to be a false positive. Patch updated and will be part of the
next for-next.

linux-next: build warning after merge of the btrfs-kdave tree

[Stephen Rothwell]

Hi David,

After merging the btrfs-kdave tree, today's linux-next build (powerpc
ppc64_defconfig) produced this warning:

fs/btrfs/inode.c: In function 'btrfs_submit_direct':
fs/btrfs/inode.c:8467:14: warning: 'bio' may be used uninitialized in this function [-Wmaybe-uninitialized]
  struct bio *bio;
              ^

I can't tell if it is a false positive or not.

-- 
Cheers,
Stephen Rothwell