From: Nick Desaulniers <ndesaulniers@google.com>
To: dennis@kernel.org
Cc: kbuild@lists.01.org,
clang-built-linux <clang-built-linux@googlegroups.com>,
kbuild test robot <lkp@intel.com>,
kbuild-all@lists.01.org, David Sterba <dsterba@suse.com>,
Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
osandov@osandov.com, kernel-team@fb.com,
linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 05/22] btrfs: add the beginning of async discard, discard workqueue
Date: Thu, 21 Nov 2019 20:27:43 -0800 [thread overview]
Message-ID: <CAKwvOdn5j37AYzmoOsaSqyYdBkjqevbTrSyGQypB+G_NgxX0fQ@mail.gmail.com> (raw)
In-Reply-To: <201911220351.HPI9gxNo%lkp@intel.com>
Hi Dennis,
Below is a 0day bot report from a build w/ Clang. Warning looks legit,
can you please take a look?
On Thu, Nov 21, 2019 at 11:27 AM kbuild test robot <lkp@intel.com> wrote:
>
> CC: kbuild-all@lists.01.org
> In-Reply-To: <63d3257efe1158a6fbbd7abe865cd9250b494438.1574282259.git.dennis@kernel.org>
> References: <63d3257efe1158a6fbbd7abe865cd9250b494438.1574282259.git.dennis@kernel.org>
> TO: Dennis Zhou <dennis@kernel.org>
> CC: David Sterba <dsterba@suse.com>, Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>, Omar Sandoval <osandov@osandov.com>
> CC: kernel-team@fb.com, linux-btrfs@vger.kernel.org, Dennis Zhou <dennis@kernel.org>
>
> Hi Dennis,
>
> I love your patch! Perhaps something to improve:
>
> [auto build test WARNING on kdave/for-next]
> [also build test WARNING on next-20191121]
> [cannot apply to v5.4-rc8]
> [if your patch is applied to the wrong git tree, please drop us a note to help
> improve the system. BTW, we also suggest to use '--base' option to specify the
> base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
>
> url: https://github.com/0day-ci/linux/commits/Dennis-Zhou/btrfs-async-discard-support/20191121-230429
> base: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next
> config: arm64-defconfig (attached as .config)
> compiler: clang version 10.0.0 (git://gitmirror/llvm_project cf823ce4ad9d04c69b7c29d236f7b14c875111c2)
> reproduce:
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # save the attached .config to linux build tree
> make.cross ARCH=arm64
>
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
> >> fs/btrfs/free-space-cache.c:3238:6: warning: variable 'trim_state' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
> if (!ret) {
> ^~~~
> fs/btrfs/free-space-cache.c:3251:53: note: uninitialized use occurs here
> __btrfs_add_free_space(fs_info, ctl, start, bytes, trim_state);
> ^~~~~~~~~~
> fs/btrfs/free-space-cache.c:3238:2: note: remove the 'if' if its condition is always true
> if (!ret) {
> ^~~~~~~~~~
> fs/btrfs/free-space-cache.c:3224:2: note: variable 'trim_state' is declared here
> enum btrfs_trim_state trim_state;
> ^
> 1 warning generated.
>
> vim +3238 fs/btrfs/free-space-cache.c
>
> 3210
> 3211 static int do_trimming(struct btrfs_block_group *block_group,
> 3212 u64 *total_trimmed, u64 start, u64 bytes,
> 3213 u64 reserved_start, u64 reserved_bytes,
> 3214 enum btrfs_trim_state reserved_trim_state,
> 3215 struct btrfs_trim_range *trim_entry)
> 3216 {
> 3217 struct btrfs_space_info *space_info = block_group->space_info;
> 3218 struct btrfs_fs_info *fs_info = block_group->fs_info;
> 3219 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
> 3220 int ret;
> 3221 int update = 0;
> 3222 u64 end = start + bytes;
> 3223 u64 reserved_end = reserved_start + reserved_bytes;
> 3224 enum btrfs_trim_state trim_state;
> 3225 u64 trimmed = 0;
> 3226
> 3227 spin_lock(&space_info->lock);
> 3228 spin_lock(&block_group->lock);
> 3229 if (!block_group->ro) {
> 3230 block_group->reserved += reserved_bytes;
> 3231 space_info->bytes_reserved += reserved_bytes;
> 3232 update = 1;
> 3233 }
> 3234 spin_unlock(&block_group->lock);
> 3235 spin_unlock(&space_info->lock);
> 3236
> 3237 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
> > 3238 if (!ret) {
> 3239 *total_trimmed += trimmed;
> 3240 trim_state = BTRFS_TRIM_STATE_TRIMMED;
> 3241 }
> 3242
> 3243 mutex_lock(&ctl->cache_writeout_mutex);
> 3244 if (reserved_start < start)
> 3245 __btrfs_add_free_space(fs_info, ctl, reserved_start,
> 3246 start - reserved_start,
> 3247 reserved_trim_state);
> 3248 if (start + bytes < reserved_start + reserved_bytes)
> 3249 __btrfs_add_free_space(fs_info, ctl, end, reserved_end - end,
> 3250 reserved_trim_state);
> 3251 __btrfs_add_free_space(fs_info, ctl, start, bytes, trim_state);
^ oops
> 3252 list_del(&trim_entry->list);
> 3253 mutex_unlock(&ctl->cache_writeout_mutex);
> 3254
> 3255 if (update) {
> 3256 spin_lock(&space_info->lock);
> 3257 spin_lock(&block_group->lock);
> 3258 if (block_group->ro)
> 3259 space_info->bytes_readonly += reserved_bytes;
> 3260 block_group->reserved -= reserved_bytes;
> 3261 space_info->bytes_reserved -= reserved_bytes;
> 3262 spin_unlock(&block_group->lock);
> 3263 spin_unlock(&space_info->lock);
> 3264 }
> 3265
> 3266 return ret;
> 3267 }
> 3268
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation
--
Thanks,
~Nick Desaulniers
next parent reply other threads:[~2019-11-22 4:27 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <201911220351.HPI9gxNo%lkp@intel.com>
2019-11-22 4:27 ` Nick Desaulniers [this message]
2019-11-25 18:59 ` [PATCH 05/22] btrfs: add the beginning of async discard, discard workqueue Dennis Zhou
2019-11-25 19:39 ` Nick Desaulniers
2019-11-26 1:42 ` Philip Li
2019-11-26 1:47 ` Nick Desaulniers
2019-11-26 4:07 ` Philip Li
2019-11-26 4:09 ` Philip Li
2019-12-14 0:22 [PATCH v6 00/22] btrfs: async discard support Dennis Zhou
2019-12-14 0:22 ` [PATCH 05/22] btrfs: add the beginning of async discard, discard workqueue Dennis Zhou
-- strict thread matches above, loose matches on Subject: below --
2019-12-09 19:45 [PATCH v5 00/22] btrfs: async discard support Dennis Zhou
2019-12-09 19:45 ` [PATCH 05/22] btrfs: add the beginning of async discard, discard workqueue Dennis Zhou
2019-11-25 19:46 [PATCH v4 00/22] btrfs: async discard support Dennis Zhou
2019-11-25 19:46 ` [PATCH 05/22] btrfs: add the beginning of async discard, discard workqueue Dennis Zhou
2019-11-20 21:50 [PATCH v3 00/22] btrfs: async discard support Dennis Zhou
2019-11-20 21:51 ` [PATCH 05/22] btrfs: add the beginning of async discard, discard workqueue Dennis Zhou
2019-10-23 22:52 [PATCH v2 00/22] btrfs: async discard support Dennis Zhou
2019-10-23 22:52 ` [PATCH 05/22] btrfs: add the beginning of async discard, discard workqueue Dennis Zhou
2019-11-11 18:49 ` David Sterba
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