Hi Christoph, kernel test robot noticed the following build warnings: https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Christoph-Hellwig/nfs-remove-dead-code-for-the-old-swap-over-NFS-implementation/20240615-161031 base: git://git.linux-nfs.org/projects/trondmy/linux-nfs.git linux-next patch link: https://lore.kernel.org/r/20240615080827.1239935-1-hch%40lst.de patch subject: [PATCH] nfs: remove dead code for the old swap over NFS implementation config: x86_64-randconfig-161-20240616 (https://download.01.org/0day-ci/archive/20240616/202406162226.EHq7u0eB-lkp@xxxxxxxxx/config) compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202406162226.EHq7u0eB-lkp@xxxxxxxxx/ smatch warnings: fs/nfs/write.c:737 nfs_inode_remove_request() warn: variable dereferenced before check 'folio' (see line 734) vim +/folio +737 fs/nfs/write.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 728 static void nfs_inode_remove_request(struct nfs_page *req) ^1da177e4c3f41 Linus Torvalds 2005-04-16 729 { 6a6d4644ce935d Scott Mayhew 2023-10-11 730 struct nfs_inode *nfsi = NFS_I(nfs_page_to_inode(req)); 6a6d4644ce935d Scott Mayhew 2023-10-11 731 20633f042fd090 Weston Andros Adamson 2014-05-15 732 if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { 0c493b5cf16e28 Trond Myklebust 2023-01-19 733 struct folio *folio = nfs_page_to_folio(req->wb_head); a43a94f57a0e00 Christoph Hellwig 2024-06-15 @734 struct address_space *mapping = folio->mapping; ^^^^^^^^^^^^^^ Dereference ^1da177e4c3f41 Linus Torvalds 2005-04-16 735 600f111ef51dc2 Matthew Wilcox (Oracle 2023-11-17 736) spin_lock(&mapping->i_private_lock); a43a94f57a0e00 Christoph Hellwig 2024-06-15 @737 if (likely(folio)) { ^^^^^ Checked too late 0c493b5cf16e28 Trond Myklebust 2023-01-19 738 folio->private = NULL; 0c493b5cf16e28 Trond Myklebust 2023-01-19 739 folio_clear_private(folio); 0c493b5cf16e28 Trond Myklebust 2023-01-19 740 clear_bit(PG_MAPPED, &req->wb_head->wb_flags); 29418aa4bd487c Mel Gorman 2012-07-31 741 } 600f111ef51dc2 Matthew Wilcox (Oracle 2023-11-17 742) spin_unlock(&mapping->i_private_lock); 20633f042fd090 Weston Andros Adamson 2014-05-15 743 } 17089a29a25a3b Weston Andros Adamson 2014-07-11 744 33ea5aaa87cdae ZhangXiaoxu 2019-09-26 745 if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) { 6a6d4644ce935d Scott Mayhew 2023-10-11 746 atomic_long_dec(&nfsi->nrequests); dd1b2026323a2d Jeff Layton 2023-09-19 747 nfs_release_request(req); 33ea5aaa87cdae ZhangXiaoxu 2019-09-26 748 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 749 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
