[kbuild-all] [sashal-linux-stable:queue-5.4 2/3] fs/btrfs/block-group.c:1189:6: warning: variable 'min_allocable_bytes' set but not used

tree: https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git queue-5.4 head: b19ca15421f87ab0b820032a1891f1e0a13bce70 commit: 07feb40c162ebecbea7d1ea560e553e32e0e8b48 [2/3] btrfs: take overcommit into account in inc_block_group_ro config: xtensa-allyesconfig (attached as .config) compiler: xtensa-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git/c... git remote add sashal-linux-stable https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git git fetch --no-tags sashal-linux-stable queue-5.4 git checkout 07feb40c162ebecbea7d1ea560e553e32e0e8b48 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=xtensa If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): In file included from arch/xtensa/include/asm/processor.h:15, from arch/xtensa/include/asm/thread_info.h:20, from arch/xtensa/include/asm/current.h:14, from include/linux/sched.h:12, from fs/btrfs/misc.h:6, from fs/btrfs/block-group.c:3: include/linux/scatterlist.h: In function 'sg_set_buf': arch/xtensa/include/asm/page.h:182:9: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] 182 | ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) | ^~ include/linux/compiler.h:78:42: note: in definition of macro 'unlikely' 78 | # define unlikely(x) __builtin_expect(!!(x), 0) | ^ include/linux/scatterlist.h:143:2: note: in expansion of macro 'BUG_ON' 143 | BUG_ON(!virt_addr_valid(buf)); | ^~~~~~ arch/xtensa/include/asm/page.h:190:32: note: in expansion of macro 'pfn_valid' 190 | #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) | ^~~~~~~~~ include/linux/scatterlist.h:143:10: note: in expansion of macro 'virt_addr_valid' 143 | BUG_ON(!virt_addr_valid(buf)); | ^~~~~~~~~~~~~~~ In file included from fs/btrfs/block-group.c:14: fs/btrfs/sysfs.h: At top level: fs/btrfs/sysfs.h:16:1: warning: type qualifiers ignored on function return type [-Wignored-qualifiers] 16 | const char * const btrfs_feature_set_name(enum btrfs_feature_set set); | ^~~~~ fs/btrfs/block-group.c: In function 'inc_block_group_ro': 1189 | u64 min_allocable_bytes; | ^~~~~~~~~~~~~~~~~~~ vim +/min_allocable_bytes +1189 fs/btrfs/block-group.c e3e0520b32bc3db Josef Bacik 2019-06-20 1171 26ce2095e03c248 Josef Bacik 2019-06-20 1172 /* 26ce2095e03c248 Josef Bacik 2019-06-20 1173 * Mark block group @cache read-only, so later write won't happen to block 26ce2095e03c248 Josef Bacik 2019-06-20 1174 * group @cache. 26ce2095e03c248 Josef Bacik 2019-06-20 1175 * 26ce2095e03c248 Josef Bacik 2019-06-20 1176 * If @force is not set, this function will only mark the block group readonly 26ce2095e03c248 Josef Bacik 2019-06-20 1177 * if we have enough free space (1M) in other metadata/system block groups. 26ce2095e03c248 Josef Bacik 2019-06-20 1178 * If @force is not set, this function will mark the block group readonly 26ce2095e03c248 Josef Bacik 2019-06-20 1179 * without checking free space. 26ce2095e03c248 Josef Bacik 2019-06-20 1180 * 26ce2095e03c248 Josef Bacik 2019-06-20 1181 * NOTE: This function doesn't care if other block groups can contain all the 26ce2095e03c248 Josef Bacik 2019-06-20 1182 * data in this block group. That check should be done by relocation routine, 26ce2095e03c248 Josef Bacik 2019-06-20 1183 * not this function. 26ce2095e03c248 Josef Bacik 2019-06-20 1184 */ e11c0406ad1bb60 Josef Bacik 2019-06-20 1185 static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force) 26ce2095e03c248 Josef Bacik 2019-06-20 1186 { 26ce2095e03c248 Josef Bacik 2019-06-20 1187 struct btrfs_space_info *sinfo = cache->space_info; 26ce2095e03c248 Josef Bacik 2019-06-20 1188 u64 num_bytes; 26ce2095e03c248 Josef Bacik 2019-06-20 @1189 u64 min_allocable_bytes; 26ce2095e03c248 Josef Bacik 2019-06-20 1190 int ret = -ENOSPC; 26ce2095e03c248 Josef Bacik 2019-06-20 1191 26ce2095e03c248 Josef Bacik 2019-06-20 1192 /* 26ce2095e03c248 Josef Bacik 2019-06-20 1193 * We need some metadata space and system metadata space for 26ce2095e03c248 Josef Bacik 2019-06-20 1194 * allocating chunks in some corner cases until we force to set 26ce2095e03c248 Josef Bacik 2019-06-20 1195 * it to be readonly. 26ce2095e03c248 Josef Bacik 2019-06-20 1196 */ 26ce2095e03c248 Josef Bacik 2019-06-20 1197 if ((sinfo->flags & 26ce2095e03c248 Josef Bacik 2019-06-20 1198 (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) && 26ce2095e03c248 Josef Bacik 2019-06-20 1199 !force) 26ce2095e03c248 Josef Bacik 2019-06-20 1200 min_allocable_bytes = SZ_1M; 26ce2095e03c248 Josef Bacik 2019-06-20 1201 else 26ce2095e03c248 Josef Bacik 2019-06-20 1202 min_allocable_bytes = 0; 26ce2095e03c248 Josef Bacik 2019-06-20 1203 26ce2095e03c248 Josef Bacik 2019-06-20 1204 spin_lock(&sinfo->lock); 26ce2095e03c248 Josef Bacik 2019-06-20 1205 spin_lock(&cache->lock); 26ce2095e03c248 Josef Bacik 2019-06-20 1206 26ce2095e03c248 Josef Bacik 2019-06-20 1207 if (cache->ro) { 26ce2095e03c248 Josef Bacik 2019-06-20 1208 cache->ro++; 26ce2095e03c248 Josef Bacik 2019-06-20 1209 ret = 0; 26ce2095e03c248 Josef Bacik 2019-06-20 1210 goto out; 26ce2095e03c248 Josef Bacik 2019-06-20 1211 } 26ce2095e03c248 Josef Bacik 2019-06-20 1212 26ce2095e03c248 Josef Bacik 2019-06-20 1213 num_bytes = cache->key.offset - cache->reserved - cache->pinned - 26ce2095e03c248 Josef Bacik 2019-06-20 1214 cache->bytes_super - btrfs_block_group_used(&cache->item); 26ce2095e03c248 Josef Bacik 2019-06-20 1215 26ce2095e03c248 Josef Bacik 2019-06-20 1216 /* 07feb40c162ebec Josef Bacik 2020-10-14 1217 * Data never overcommits, even in mixed mode, so do just the straight 07feb40c162ebec Josef Bacik 2020-10-14 1218 * check of left over space in how much we have allocated. 07feb40c162ebec Josef Bacik 2020-10-14 1219 */ 07feb40c162ebec Josef Bacik 2020-10-14 1220 if (force) { 07feb40c162ebec Josef Bacik 2020-10-14 1221 ret = 0; 07feb40c162ebec Josef Bacik 2020-10-14 1222 } else if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA) { 07feb40c162ebec Josef Bacik 2020-10-14 1223 u64 sinfo_used = btrfs_space_info_used(sinfo, true); 07feb40c162ebec Josef Bacik 2020-10-14 1224 07feb40c162ebec Josef Bacik 2020-10-14 1225 /* 26ce2095e03c248 Josef Bacik 2019-06-20 1226 * Here we make sure if we mark this bg RO, we still have enough 07feb40c162ebec Josef Bacik 2020-10-14 1227 * free space as buffer. 07feb40c162ebec Josef Bacik 2020-10-14 1228 */ 07feb40c162ebec Josef Bacik 2020-10-14 1229 if (sinfo_used + num_bytes <= sinfo->total_bytes) 07feb40c162ebec Josef Bacik 2020-10-14 1230 ret = 0; 07feb40c162ebec Josef Bacik 2020-10-14 1231 } else { 07feb40c162ebec Josef Bacik 2020-10-14 1232 /* 07feb40c162ebec Josef Bacik 2020-10-14 1233 * We overcommit metadata, so we need to do the 07feb40c162ebec Josef Bacik 2020-10-14 1234 * btrfs_can_overcommit check here, and we need to pass in 07feb40c162ebec Josef Bacik 2020-10-14 1235 * BTRFS_RESERVE_NO_FLUSH to give ourselves the most amount of 07feb40c162ebec Josef Bacik 2020-10-14 1236 * leeway to allow us to mark this block group as read only. 26ce2095e03c248 Josef Bacik 2019-06-20 1237 */ 07feb40c162ebec Josef Bacik 2020-10-14 1238 if (btrfs_can_overcommit(cache->fs_info, sinfo, num_bytes, 07feb40c162ebec Josef Bacik 2020-10-14 1239 BTRFS_RESERVE_NO_FLUSH)) 07feb40c162ebec Josef Bacik 2020-10-14 1240 ret = 0; 07feb40c162ebec Josef Bacik 2020-10-14 1241 } 07feb40c162ebec Josef Bacik 2020-10-14 1242 07feb40c162ebec Josef Bacik 2020-10-14 1243 if (!ret) { 26ce2095e03c248 Josef Bacik 2019-06-20 1244 sinfo->bytes_readonly += num_bytes; 26ce2095e03c248 Josef Bacik 2019-06-20 1245 cache->ro++; 26ce2095e03c248 Josef Bacik 2019-06-20 1246 list_add_tail(&cache->ro_list, &sinfo->ro_bgs); 26ce2095e03c248 Josef Bacik 2019-06-20 1247 } 26ce2095e03c248 Josef Bacik 2019-06-20 1248 out: 26ce2095e03c248 Josef Bacik 2019-06-20 1249 spin_unlock(&cache->lock); 26ce2095e03c248 Josef Bacik 2019-06-20 1250 spin_unlock(&sinfo->lock); 26ce2095e03c248 Josef Bacik 2019-06-20 1251 if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) { 26ce2095e03c248 Josef Bacik 2019-06-20 1252 btrfs_info(cache->fs_info, 26ce2095e03c248 Josef Bacik 2019-06-20 1253 "unable to make block group %llu ro", 26ce2095e03c248 Josef Bacik 2019-06-20 1254 cache->key.objectid); 26ce2095e03c248 Josef Bacik 2019-06-20 1255 btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0); 26ce2095e03c248 Josef Bacik 2019-06-20 1256 } 26ce2095e03c248 Josef Bacik 2019-06-20 1257 return ret; 26ce2095e03c248 Josef Bacik 2019-06-20 1258 } 26ce2095e03c248 Josef Bacik 2019-06-20 1259 :::::: The code at line 1189 was first introduced by commit :::::: 26ce2095e03c248759951d81fdff37e2bf32601c btrfs: migrate inc/dec_block_group_ro code :::::: TO: Josef Bacik <josef(a)toxicpanda.com&gt; :::::: CC: David Sterba <dsterba(a)suse.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org