Hi Jiapeng, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on vfs-idmapping/for-next] [also build test WARNING on linus/master v6.3-rc3 next-20230322] [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/Jiapeng-Chong/fs-buffer-Remove-redundant-assignment-to-err/20230322-150022 base: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping.git for-next patch link: https://lore.kernel.org/r/20230322065949.29223-1-jiapeng.chong%40linux.alibaba.com patch subject: [PATCH] fs/buffer: Remove redundant assignment to err config: hexagon-randconfig-r036-20230322 (https://download.01.org/0day-ci/archive/20230322/202303221812.QiRW1CXX-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 67409911353323ca5edf2049ef0df54132fa1ca7) 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://github.com/intel-lab-lkp/linux/commit/3e00c2b4797c228b1939a15506c9ab807d0fa809 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Jiapeng-Chong/fs-buffer-Remove-redundant-assignment-to-err/20230322-150022 git checkout 3e00c2b4797c228b1939a15506c9ab807d0fa809 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Link: https://lore.kernel.org/oe-kbuild-all/202303221812.QiRW1CXX-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from fs/buffer.c:24: In file included from include/linux/syscalls.h:88: In file included from include/trace/syscall.h:7: In file included from include/linux/trace_events.h:9: In file included from include/linux/hardirq.h:11: In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/hexagon/include/asm/io.h:334: include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from fs/buffer.c:24: In file included from include/linux/syscalls.h:88: In file included from include/trace/syscall.h:7: In file included from include/linux/trace_events.h:9: In file included from include/linux/hardirq.h:11: In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/hexagon/include/asm/io.h:334: include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from fs/buffer.c:24: In file included from include/linux/syscalls.h:88: In file included from include/trace/syscall.h:7: In file included from include/linux/trace_events.h:9: In file included from include/linux/hardirq.h:11: In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/hexagon/include/asm/io.h:334: include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ >> fs/buffer.c:2639:1: warning: unused label 'out' [-Wunused-label] out: ^~~~ fs/buffer.c:2282:5: warning: stack frame size (2144) exceeds limit (1024) in 'block_read_full_folio' [-Wframe-larger-than] int block_read_full_folio(struct folio *folio, get_block_t *get_block) ^ 79/2144 (3.68%) spills, 2065/2144 (96.32%) variables 8 warnings generated. vim +/out +2639 fs/buffer.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 2572 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2573 int block_truncate_page(struct address_space *mapping, ^1da177e4c3f41 Linus Torvalds 2005-04-16 2574 loff_t from, get_block_t *get_block) ^1da177e4c3f41 Linus Torvalds 2005-04-16 2575 { 09cbfeaf1a5a67 Kirill A. Shutemov 2016-04-01 2576 pgoff_t index = from >> PAGE_SHIFT; 09cbfeaf1a5a67 Kirill A. Shutemov 2016-04-01 2577 unsigned offset = from & (PAGE_SIZE-1); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2578 unsigned blocksize; 54b21a7992a31d Andrew Morton 2006-01-08 2579 sector_t iblock; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2580 unsigned length, pos; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2581 struct inode *inode = mapping->host; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2582 struct page *page; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2583 struct buffer_head *bh; 3e00c2b4797c22 Jiapeng Chong 2023-03-22 2584 int err = 0; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2585 93407472a21b82 Fabian Frederick 2017-02-27 2586 blocksize = i_blocksize(inode); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2587 length = offset & (blocksize - 1); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2588 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2589 /* Block boundary? Nothing to do */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 2590 if (!length) ^1da177e4c3f41 Linus Torvalds 2005-04-16 2591 return 0; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2592 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2593 length = blocksize - length; 09cbfeaf1a5a67 Kirill A. Shutemov 2016-04-01 2594 iblock = (sector_t)index << (PAGE_SHIFT - inode->i_blkbits); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2595 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2596 page = grab_cache_page(mapping, index); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2597 if (!page) 3e00c2b4797c22 Jiapeng Chong 2023-03-22 2598 return -ENOMEM; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2599 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2600 if (!page_has_buffers(page)) ^1da177e4c3f41 Linus Torvalds 2005-04-16 2601 create_empty_buffers(page, blocksize, 0); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2602 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2603 /* Find the buffer that contains "offset" */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 2604 bh = page_buffers(page); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2605 pos = blocksize; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2606 while (offset >= pos) { ^1da177e4c3f41 Linus Torvalds 2005-04-16 2607 bh = bh->b_this_page; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2608 iblock++; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2609 pos += blocksize; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2610 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 2611 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2612 if (!buffer_mapped(bh)) { b0cf2321c65991 Badari Pulavarty 2006-03-26 2613 WARN_ON(bh->b_size != blocksize); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2614 err = get_block(inode, iblock, bh, 0); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2615 if (err) ^1da177e4c3f41 Linus Torvalds 2005-04-16 2616 goto unlock; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2617 /* unmapped? It's a hole - nothing to do */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 2618 if (!buffer_mapped(bh)) ^1da177e4c3f41 Linus Torvalds 2005-04-16 2619 goto unlock; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2620 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 2621 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2622 /* Ok, it's mapped. Make sure it's up-to-date */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 2623 if (PageUptodate(page)) ^1da177e4c3f41 Linus Torvalds 2005-04-16 2624 set_buffer_uptodate(bh); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2625 33a266dda9fbbe David Chinner 2007-02-12 2626 if (!buffer_uptodate(bh) && !buffer_delay(bh) && !buffer_unwritten(bh)) { e7ea1129afab0e Zhang Yi 2022-09-01 2627 err = bh_read(bh, 0); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2628 /* Uhhuh. Read error. Complain and punt. */ e7ea1129afab0e Zhang Yi 2022-09-01 2629 if (err < 0) ^1da177e4c3f41 Linus Torvalds 2005-04-16 2630 goto unlock; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2631 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 2632 eebd2aa355692a Christoph Lameter 2008-02-04 2633 zero_user(page, offset, length); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2634 mark_buffer_dirty(bh); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2635 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2636 unlock: ^1da177e4c3f41 Linus Torvalds 2005-04-16 2637 unlock_page(page); 09cbfeaf1a5a67 Kirill A. Shutemov 2016-04-01 2638 put_page(page); ^1da177e4c3f41 Linus Torvalds 2005-04-16 @2639 out: ^1da177e4c3f41 Linus Torvalds 2005-04-16 2640 return err; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2641 } 1fe72eaa0f46a0 H Hartley Sweeten 2009-09-22 2642 EXPORT_SYMBOL(block_truncate_page); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2643 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests
