Hi Nikolay, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on kdave/for-next] [also build test WARNING on next-20201112] [cannot apply to btrfs/next v5.10-rc3] [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] url: https://github.com/0day-ci/linux/commits/Nikolay-Borisov/btrfs-Simplify-s... base: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next config: riscv-randconfig-r014-20201112 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project a7b65741441556d295079fc4f2391d99fd1c1111) 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 # install riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://github.com/0day-ci/linux/commit/aea2237f4b88d91fc8ad6469b205ff6ad... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Nikolay-Borisov/btrfs-Simplify-setup_nodes_for_search/20201112-191847 git checkout aea2237f4b88d91fc8ad6469b205ff6ada2fcf55 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 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/riscv/include/asm/io.h:149: include/asm-generic/io.h:564:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return inw(addr); ^~~~~~~~~ arch/riscv/include/asm/io.h:56:76: note: expanded from macro 'inw' #define inw(c) ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:88:76: note: expanded from macro 'readw_cpu' #define readw_cpu(c) ({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; }) ^ include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from fs/btrfs/ctree.c:10: In file included from fs/btrfs/ctree.h:11: In file included from include/linux/highmem.h:10: In file included from include/linux/hardirq.h:10: In file included from ./arch/riscv/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:13: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:572:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return inl(addr); ^~~~~~~~~ arch/riscv/include/asm/io.h:57:76: note: expanded from macro 'inl' #define inl(c) ({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:89:76: note: expanded from macro 'readl_cpu' #define readl_cpu(c) ({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; }) ^ include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from fs/btrfs/ctree.c:10: In file included from fs/btrfs/ctree.h:11: In file included from include/linux/highmem.h:10: In file included from include/linux/hardirq.h:10: In file included from ./arch/riscv/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:13: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:580:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] outb(value, addr); ^~~~~~~~~~~~~~~~~ arch/riscv/include/asm/io.h:59:68: note: expanded from macro 'outb' #define outb(v,c) ({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:91:52: note: expanded from macro 'writeb_cpu' #define writeb_cpu(v, c) ((void)__raw_writeb((v), (c))) ^ In file included from fs/btrfs/ctree.c:10: In file included from fs/btrfs/ctree.h:11: In file included from include/linux/highmem.h:10: In file included from include/linux/hardirq.h:10: In file included from ./arch/riscv/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:13: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:588:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] outw(value, addr); ^~~~~~~~~~~~~~~~~ arch/riscv/include/asm/io.h:60:68: note: expanded from macro 'outw' #define outw(v,c) ({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:92:76: note: expanded from macro 'writew_cpu' #define writew_cpu(v, c) ((void)__raw_writew((__force u16)cpu_to_le16(v), (c))) ^ In file included from fs/btrfs/ctree.c:10: In file included from fs/btrfs/ctree.h:11: In file included from include/linux/highmem.h:10: In file included from include/linux/hardirq.h:10: In file included from ./arch/riscv/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:13: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:596:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] outl(value, addr); ^~~~~~~~~~~~~~~~~ arch/riscv/include/asm/io.h:61:68: note: expanded from macro 'outl' #define outl(v,c) ({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); }) ~~~~~~~~~~ ^ arch/riscv/include/asm/mmio.h:93:76: note: expanded from macro 'writel_cpu' #define writel_cpu(v, c) ((void)__raw_writel((__force u32)cpu_to_le32(v), (c))) ^ In file included from fs/btrfs/ctree.c:10: In file included from fs/btrfs/ctree.h:11: In file included from include/linux/highmem.h:10: In file included from include/linux/hardirq.h:10: In file included from ./arch/riscv/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:13: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/riscv/include/asm/io.h:149: include/asm-generic/io.h:1005:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port; ~~~~~~~~~~ ^ } else if (ins_len < 0 && btrfs_header_nritems(b) < ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/btrfs/ctree.c:2429:9: note: uninitialized use occurs here return ret; ^~~ fs/btrfs/ctree.c:2408:9: note: remove the 'if' if its condition is always true } else if (ins_len < 0 && btrfs_header_nritems(b) < ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ } else if (ins_len < 0 && btrfs_header_nritems(b) < ^~~~~~~~~~~ fs/btrfs/ctree.c:2429:9: note: uninitialized use occurs here return ret; ^~~ fs/btrfs/ctree.c:2408:13: note: remove the '&&' if its condition is always true } else if (ins_len < 0 && btrfs_header_nritems(b) < ^~~~~~~~~~~~~~ fs/btrfs/ctree.c:2393:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 9 warnings generated. vim +2408 fs/btrfs/ctree.c c8c42864f619363 Chris Mason 2009-04-03 2376 c8c42864f619363 Chris Mason 2009-04-03 2377 /* c8c42864f619363 Chris Mason 2009-04-03 2378 * helper function for btrfs_search_slot. This does all of the checks c8c42864f619363 Chris Mason 2009-04-03 2379 * for node-level blocks and does any balancing required based on c8c42864f619363 Chris Mason 2009-04-03 2380 * the ins_len. c8c42864f619363 Chris Mason 2009-04-03 2381 * c8c42864f619363 Chris Mason 2009-04-03 2382 * If no extra work was required, zero is returned. If we had to c8c42864f619363 Chris Mason 2009-04-03 2383 * drop the path, -EAGAIN is returned and btrfs_search_slot must c8c42864f619363 Chris Mason 2009-04-03 2384 * start over c8c42864f619363 Chris Mason 2009-04-03 2385 */ c8c42864f619363 Chris Mason 2009-04-03 2386 static int c8c42864f619363 Chris Mason 2009-04-03 2387 setup_nodes_for_search(struct btrfs_trans_handle *trans, c8c42864f619363 Chris Mason 2009-04-03 2388 struct btrfs_root *root, struct btrfs_path *p, bd681513fa6f2ff Chris Mason 2011-07-16 2389 struct extent_buffer *b, int level, int ins_len, bd681513fa6f2ff Chris Mason 2011-07-16 2390 int *write_lock_level) c8c42864f619363 Chris Mason 2009-04-03 2391 { 0b246afa62b0cf5 Jeff Mahoney 2016-06-22 2392 struct btrfs_fs_info *fs_info = root->fs_info; c8c42864f619363 Chris Mason 2009-04-03 2393 int ret; 0b246afa62b0cf5 Jeff Mahoney 2016-06-22 2394 c8c42864f619363 Chris Mason 2009-04-03 2395 if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= 0b246afa62b0cf5 Jeff Mahoney 2016-06-22 2396 BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { c8c42864f619363 Chris Mason 2009-04-03 2397 bd681513fa6f2ff Chris Mason 2011-07-16 2398 if (*write_lock_level < level + 1) { bd681513fa6f2ff Chris Mason 2011-07-16 2399 *write_lock_level = level + 1; bd681513fa6f2ff Chris Mason 2011-07-16 2400 btrfs_release_path(p); aea2237f4b88d91 Nikolay Borisov 2020-11-12 2401 return -EAGAIN; bd681513fa6f2ff Chris Mason 2011-07-16 2402 } bd681513fa6f2ff Chris Mason 2011-07-16 2403 480b65236526f4c Josef Bacik 2020-11-05 2404 reada_for_balance(p, level); aea2237f4b88d91 Nikolay Borisov 2020-11-12 2405 ret = split_node(trans, root, p, level); c8c42864f619363 Chris Mason 2009-04-03 2406 c8c42864f619363 Chris Mason 2009-04-03 2407 b = p->nodes[level]; c8c42864f619363 Chris Mason 2009-04-03 @2408 } else if (ins_len < 0 && btrfs_header_nritems(b) < 0b246afa62b0cf5 Jeff Mahoney 2016-06-22 2409 BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { c8c42864f619363 Chris Mason 2009-04-03 2410 bd681513fa6f2ff Chris Mason 2011-07-16 2411 if (*write_lock_level < level + 1) { bd681513fa6f2ff Chris Mason 2011-07-16 2412 *write_lock_level = level + 1; bd681513fa6f2ff Chris Mason 2011-07-16 2413 btrfs_release_path(p); aea2237f4b88d91 Nikolay Borisov 2020-11-12 2414 return -EAGAIN; bd681513fa6f2ff Chris Mason 2011-07-16 2415 } bd681513fa6f2ff Chris Mason 2011-07-16 2416 480b65236526f4c Josef Bacik 2020-11-05 2417 reada_for_balance(p, level); aea2237f4b88d91 Nikolay Borisov 2020-11-12 2418 ret = balance_level(trans, root, p, level); aea2237f4b88d91 Nikolay Borisov 2020-11-12 2419 if (ret) aea2237f4b88d91 Nikolay Borisov 2020-11-12 2420 return ret; c8c42864f619363 Chris Mason 2009-04-03 2421 c8c42864f619363 Chris Mason 2009-04-03 2422 b = p->nodes[level]; c8c42864f619363 Chris Mason 2009-04-03 2423 if (!b) { b3b4aa74b58bded David Sterba 2011-04-21 2424 btrfs_release_path(p); aea2237f4b88d91 Nikolay Borisov 2020-11-12 2425 return -EAGAIN; c8c42864f619363 Chris Mason 2009-04-03 2426 } c8c42864f619363 Chris Mason 2009-04-03 2427 BUG_ON(btrfs_header_nritems(b) == 1); c8c42864f619363 Chris Mason 2009-04-03 2428 } c8c42864f619363 Chris Mason 2009-04-03 2429 return ret; c8c42864f619363 Chris Mason 2009-04-03 2430 } c8c42864f619363 Chris Mason 2009-04-03 2431 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org