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@xxxxxxxxx> wrote: > > CC: kbuild-all@xxxxxxxxxxxx > In-Reply-To: <63d3257efe1158a6fbbd7abe865cd9250b494438.1574282259.git.dennis@xxxxxxxxxx> > References: <63d3257efe1158a6fbbd7abe865cd9250b494438.1574282259.git.dennis@xxxxxxxxxx> > TO: Dennis Zhou <dennis@xxxxxxxxxx> > CC: David Sterba <dsterba@xxxxxxxx>, Chris Mason <clm@xxxxxx>, Josef Bacik <josef@xxxxxxxxxxxxxx>, Omar Sandoval <osandov@xxxxxxxxxxx> > CC: kernel-team@xxxxxx, linux-btrfs@xxxxxxxxxxxxxxx, Dennis Zhou <dennis@xxxxxxxxxx> > > 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@xxxxxxxxx> > > 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@xxxxxxxxxxxx Intel Corporation -- Thanks, ~Nick Desaulniers
