Re: [PATCH v3 1/2] scsi: sg: fix blktrace debugfs entries leakage

[Yu Kuai]

Hi,

在 2023/06/09 0:02, kernel test robot 写道:
> Hi Yu,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on axboe-block/for-next]
> [also build test WARNING on linus/master v6.4-rc5 next-20230608]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Yu-Kuai/scsi-sg-fix-blktrace-debugfs-entries-leakage/20230608-104735
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next
> patch link:    https://lore.kernel.org/r/20230608024159.1282953-2-yukuai1%40huaweicloud.com
> patch subject: [PATCH v3 1/2] scsi: sg: fix blktrace debugfs entries leakage
> config: i386-randconfig-r002-20230608 (https://download.01.org/0day-ci/archive/20230608/202306082353.o2lpbQcL-lkp@xxxxxxxxx/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce (this is a W=1 build):
>          git remote add axboe-block https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
>          git fetch axboe-block for-next
>          git checkout axboe-block/for-next
>          b4 shazam https://lore.kernel.org/r/20230608024159.1282953-2-yukuai1@xxxxxxxxxxxxxxx
>          # save the config file
>          mkdir build_dir && cp config build_dir/.config
>          make W=1 O=build_dir ARCH=i386 olddefconfig
>          make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202306082353.o2lpbQcL-lkp@xxxxxxxxx/
>
> All warnings (new ones prefixed by >>):
>
>     In file included from drivers/scsi/sg.c:45:
>     drivers/scsi/sg.c: In function 'sg_device_destroy':
> > > include/linux/blktrace_api.h:88:57: warning: statement with no effect [-Wunused-value]
>        88 | # define blk_trace_remove(q)                            (-ENOTTY)
>           |        

So, this warning happens in all the caller of blk_trace_remove() when
CONFIG_BLK_DEV_IO_TRACE is disabled that doesn't handle the return
value. I'll use blk_trace_shutdown() instead to avoid this warning.
                                                 ^
Thanks,
Kuai
>     drivers/scsi/sg.c:1575:9: note: in expansion of macro 'blk_trace_remove'
>      1575 |         blk_trace_remove(sdp->device->request_queue);
>           |         ^~~~~~~~~~~~~~~~
>
>
> vim +88 include/linux/blktrace_api.h
>
> 157f9c00e88529 Arnaldo Carvalho de Melo 2009-01-26  81
> 2056a782f8e7e6 Jens Axboe               2006-03-23  82  #else /* !CONFIG_BLK_DEV_IO_TRACE */
> 2056a782f8e7e6 Jens Axboe               2006-03-23  83  # define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
> 2056a782f8e7e6 Jens Axboe               2006-03-23  84  # define blk_trace_shutdown(q)				do { } while (0)
> a54895fa057c67 Christoph Hellwig        2020-12-03  85  # define blk_add_driver_data(rq, data, len)		do {} while (0)
> d0deef5b14af7d Shawn Du                 2009-04-14  86  # define blk_trace_setup(q, name, dev, bdev, arg)	(-ENOTTY)
> 6da127ad0918f9 Christof Schmitt         2008-01-11  87  # define blk_trace_startstop(q, start)			(-ENOTTY)
> 6da127ad0918f9 Christof Schmitt         2008-01-11 @88  # define blk_trace_remove(q)				(-ENOTTY)
> 9d5f09a424a67d Alan D. Brunelle         2008-05-27  89  # define blk_add_trace_msg(q, fmt, ...)			do { } while (0)
> 35fe6d763229e8 Shaohua Li               2017-07-12  90  # define blk_add_cgroup_trace_msg(q, cg, fmt, ...)	do { } while (0)
> 59fa0224cfea31 Shaohua Li               2016-05-09  91  # define blk_trace_note_message_enabled(q)		(false)
> 2056a782f8e7e6 Jens Axboe               2006-03-23  92  #endif /* CONFIG_BLK_DEV_IO_TRACE */
> d0deef5b14af7d Shawn Du                 2009-04-14  93