Hi NeilBrown, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on kdave/for-next] [also build test WARNING on ext3/fsnotify linus/master v5.14-rc5 next-20210806] [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/NeilBrown/Attempt-to-make-progress-with-btrfs-dev-number-strangeness/20210809-120046 base: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next config: x86_64-randconfig-c001-20210809 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c5c3cdb9c92895a63993cee70d2dd776ff9519c3) 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/0day-ci/linux/commit/c5bae87ed5b72b9fd999fa935f477483da001f63 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review NeilBrown/Attempt-to-make-progress-with-btrfs-dev-number-strangeness/20210809-120046 git checkout c5bae87ed5b72b9fd999fa935f477483da001f63 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> fs/btrfs/ioctl.c:740:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (fs_info->num_devs == BTRFS_MANY_DEVS) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/btrfs/ioctl.c:742:6: note: uninitialized use occurs here if (ret < 0) ^~~ fs/btrfs/ioctl.c:740:2: note: remove the 'if' if its condition is always true if (fs_info->num_devs == BTRFS_MANY_DEVS) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/btrfs/ioctl.c:725:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 warning generated. vim +740 fs/btrfs/ioctl.c 716 717 static int create_snapshot(struct btrfs_root *root, struct inode *dir, 718 struct dentry *dentry, bool readonly, 719 struct btrfs_qgroup_inherit *inherit) 720 { 721 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); 722 struct inode *inode; 723 struct btrfs_pending_snapshot *pending_snapshot; 724 struct btrfs_trans_handle *trans; 725 int ret; 726 727 if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) 728 return -EINVAL; 729 730 if (atomic_read(&root->nr_swapfiles)) { 731 btrfs_warn(fs_info, 732 "cannot snapshot subvolume with active swapfile"); 733 return -ETXTBSY; 734 } 735 736 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL); 737 if (!pending_snapshot) 738 return -ENOMEM; 739 > 740 if (fs_info->num_devs == BTRFS_MANY_DEVS) 741 ret = get_anon_bdev(&pending_snapshot->anon_dev); 742 if (ret < 0) 743 goto free_pending; 744 pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item), 745 GFP_KERNEL); 746 pending_snapshot->path = btrfs_alloc_path(); 747 if (!pending_snapshot->root_item || !pending_snapshot->path) { 748 ret = -ENOMEM; 749 goto free_pending; 750 } 751 752 btrfs_init_block_rsv(&pending_snapshot->block_rsv, 753 BTRFS_BLOCK_RSV_TEMP); 754 /* 755 * 1 - parent dir inode 756 * 2 - dir entries 757 * 1 - root item 758 * 2 - root ref/backref 759 * 1 - root of snapshot 760 * 1 - UUID item 761 */ 762 ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root, 763 &pending_snapshot->block_rsv, 8, 764 false); 765 if (ret) 766 goto free_pending; 767 768 pending_snapshot->dentry = dentry; 769 pending_snapshot->root = root; 770 pending_snapshot->readonly = readonly; 771 pending_snapshot->dir = dir; 772 pending_snapshot->inherit = inherit; 773 774 trans = btrfs_start_transaction(root, 0); 775 if (IS_ERR(trans)) { 776 ret = PTR_ERR(trans); 777 goto fail; 778 } 779 780 spin_lock(&fs_info->trans_lock); 781 list_add(&pending_snapshot->list, 782 &trans->transaction->pending_snapshots); 783 spin_unlock(&fs_info->trans_lock); 784 785 ret = btrfs_commit_transaction(trans); 786 if (ret) 787 goto fail; 788 789 ret = pending_snapshot->error; 790 if (ret) 791 goto fail; 792 793 ret = btrfs_orphan_cleanup(pending_snapshot->snap); 794 if (ret) 795 goto fail; 796 797 inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry); 798 if (IS_ERR(inode)) { 799 ret = PTR_ERR(inode); 800 goto fail; 801 } 802 803 d_instantiate(dentry, inode); 804 ret = 0; 805 pending_snapshot->anon_dev = 0; 806 fail: 807 /* Prevent double freeing of anon_dev */ 808 if (ret && pending_snapshot->snap) 809 pending_snapshot->snap->anon_dev = 0; 810 btrfs_put_root(pending_snapshot->snap); 811 btrfs_subvolume_release_metadata(root, &pending_snapshot->block_rsv); 812 free_pending: 813 if (pending_snapshot->anon_dev) 814 free_anon_bdev(pending_snapshot->anon_dev); 815 kfree(pending_snapshot->root_item); 816 btrfs_free_path(pending_snapshot->path); 817 kfree(pending_snapshot); 818 819 return ret; 820 } 821 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
Attachment:
.config.gz
Description: application/gzip
