fs/btrfs/root-tree.c:259:7: warning: Variable 'err' is reassigned a value before the old one has been used. [redundantAssignment]

From: kbuild test robot
Date: Sat Apr 11 2020 - 04:11:03 EST

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: ab6f762f0f53162d41497708b33c9a3236d3609e
commit: e59d18b45d081d66a2fb1a9d144fa82d4807b18d btrfs: make btrfs_find_orphan_roots use btrfs_get_fs_root
date: 3 weeks ago

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@xxxxxxxxx>


cppcheck warnings: (new ones prefixed by >>)

>> fs/btrfs/root-tree.c:259:7: warning: Variable 'err' is reassigned a value before the old one has been used. [redundantAssignment]
err = PTR_ERR_OR_ZERO(root);
^
fs/btrfs/root-tree.c:242:9: note: err is assigned
err = ret;
^
fs/btrfs/root-tree.c:259:7: note: err is overwritten
err = PTR_ERR_OR_ZERO(root);
^
fs/btrfs/root-tree.c:212:24: warning: The scope of the variable 'leaf' can be reduced. [variableScope]
struct extent_buffer *leaf;
^
fs/btrfs/root-tree.c:218:6: warning: The scope of the variable 'ret' can be reduced. [variableScope]
int ret;
^
fs/btrfs/root-tree.c:451:22: warning: Shifting signed 32-bit value by 31 bits is implementation-defined behaviour [shiftTooManyBitsSigned]
if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
^
fs/btrfs/root-tree.c:452:18: warning: Shifting signed 32-bit value by 31 bits is implementation-defined behaviour [shiftTooManyBitsSigned]
inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
^

vim +/err +259 fs/btrfs/root-tree.c

3768f3689fc76e Chris Mason 2007-03-13 208
6bccf3ab1e1f09 Jeff Mahoney 2016-06-21 209 int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info)
76dda93c6ae2c1 Yan, Zheng 2009-09-21 210 {
6bccf3ab1e1f09 Jeff Mahoney 2016-06-21 211 struct btrfs_root *tree_root = fs_info->tree_root;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 212 struct extent_buffer *leaf;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 213 struct btrfs_path *path;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 214 struct btrfs_key key;
d68fc57b7e3245 Yan, Zheng 2010-05-16 215 struct btrfs_key root_key;
d68fc57b7e3245 Yan, Zheng 2010-05-16 216 struct btrfs_root *root;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 217 int err = 0;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 218 int ret;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 219
76dda93c6ae2c1 Yan, Zheng 2009-09-21 220 path = btrfs_alloc_path();
76dda93c6ae2c1 Yan, Zheng 2009-09-21 221 if (!path)
76dda93c6ae2c1 Yan, Zheng 2009-09-21 222 return -ENOMEM;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 223
76dda93c6ae2c1 Yan, Zheng 2009-09-21 224 key.objectid = BTRFS_ORPHAN_OBJECTID;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 225 key.type = BTRFS_ORPHAN_ITEM_KEY;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 226 key.offset = 0;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 227
d68fc57b7e3245 Yan, Zheng 2010-05-16 228 root_key.type = BTRFS_ROOT_ITEM_KEY;
d68fc57b7e3245 Yan, Zheng 2010-05-16 229 root_key.offset = (u64)-1;
d68fc57b7e3245 Yan, Zheng 2010-05-16 230
76dda93c6ae2c1 Yan, Zheng 2009-09-21 231 while (1) {
76dda93c6ae2c1 Yan, Zheng 2009-09-21 232 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
76dda93c6ae2c1 Yan, Zheng 2009-09-21 233 if (ret < 0) {
76dda93c6ae2c1 Yan, Zheng 2009-09-21 234 err = ret;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 235 break;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 236 }
76dda93c6ae2c1 Yan, Zheng 2009-09-21 237
76dda93c6ae2c1 Yan, Zheng 2009-09-21 238 leaf = path->nodes[0];
76dda93c6ae2c1 Yan, Zheng 2009-09-21 239 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
76dda93c6ae2c1 Yan, Zheng 2009-09-21 240 ret = btrfs_next_leaf(tree_root, path);
76dda93c6ae2c1 Yan, Zheng 2009-09-21 241 if (ret < 0)
76dda93c6ae2c1 Yan, Zheng 2009-09-21 242 err = ret;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 243 if (ret != 0)
76dda93c6ae2c1 Yan, Zheng 2009-09-21 244 break;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 245 leaf = path->nodes[0];
76dda93c6ae2c1 Yan, Zheng 2009-09-21 246 }
76dda93c6ae2c1 Yan, Zheng 2009-09-21 247
76dda93c6ae2c1 Yan, Zheng 2009-09-21 248 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
b3b4aa74b58bde David Sterba 2011-04-21 249 btrfs_release_path(path);
76dda93c6ae2c1 Yan, Zheng 2009-09-21 250
76dda93c6ae2c1 Yan, Zheng 2009-09-21 251 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
76dda93c6ae2c1 Yan, Zheng 2009-09-21 252 key.type != BTRFS_ORPHAN_ITEM_KEY)
76dda93c6ae2c1 Yan, Zheng 2009-09-21 253 break;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 254
d68fc57b7e3245 Yan, Zheng 2010-05-16 255 root_key.objectid = key.offset;
d68fc57b7e3245 Yan, Zheng 2010-05-16 256 key.offset++;
d68fc57b7e3245 Yan, Zheng 2010-05-16 257
e59d18b45d081d Josef Bacik 2020-01-24 258 root = btrfs_get_fs_root(fs_info, &root_key, false);
886322e8e78760 Sachin Kamat 2014-02-17 @259 err = PTR_ERR_OR_ZERO(root);
68a7342c51c950 Josef Bacik 2013-06-27 260 if (err && err != -ENOENT) {
68a7342c51c950 Josef Bacik 2013-06-27 261 break;
68a7342c51c950 Josef Bacik 2013-06-27 262 } else if (err == -ENOENT) {
68a7342c51c950 Josef Bacik 2013-06-27 263 struct btrfs_trans_handle *trans;
68a7342c51c950 Josef Bacik 2013-06-27 264
68a7342c51c950 Josef Bacik 2013-06-27 265 btrfs_release_path(path);
68a7342c51c950 Josef Bacik 2013-06-27 266
68a7342c51c950 Josef Bacik 2013-06-27 267 trans = btrfs_join_transaction(tree_root);
68a7342c51c950 Josef Bacik 2013-06-27 268 if (IS_ERR(trans)) {
68a7342c51c950 Josef Bacik 2013-06-27 269 err = PTR_ERR(trans);
0b246afa62b0cf Jeff Mahoney 2016-06-22 270 btrfs_handle_fs_error(fs_info, err,
5d163e0e68ce74 Jeff Mahoney 2016-09-20 271 "Failed to start trans to delete orphan item");
cb517eabba4f10 Miao Xie 2013-05-15 272 break;
cb517eabba4f10 Miao Xie 2013-05-15 273 }
68a7342c51c950 Josef Bacik 2013-06-27 274 err = btrfs_del_orphan_item(trans, tree_root,
68a7342c51c950 Josef Bacik 2013-06-27 275 root_key.objectid);
3a45bb207ee2c5 Jeff Mahoney 2016-09-09 276 btrfs_end_transaction(trans);
68a7342c51c950 Josef Bacik 2013-06-27 277 if (err) {
0b246afa62b0cf Jeff Mahoney 2016-06-22 278 btrfs_handle_fs_error(fs_info, err,
5d163e0e68ce74 Jeff Mahoney 2016-09-20 279 "Failed to delete root orphan item");
68a7342c51c950 Josef Bacik 2013-06-27 280 break;
68a7342c51c950 Josef Bacik 2013-06-27 281 }
68a7342c51c950 Josef Bacik 2013-06-27 282 continue;
68a7342c51c950 Josef Bacik 2013-06-27 283 }
cb517eabba4f10 Miao Xie 2013-05-15 284
e59d18b45d081d Josef Bacik 2020-01-24 285 WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state));
78c52d9eb6b7ac Josef Bacik 2019-02-06 286 if (btrfs_root_refs(&root->root_item) == 0) {
78c52d9eb6b7ac Josef Bacik 2019-02-06 287 set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
14927d95464956 Miao Xie 2013-09-25 288 btrfs_add_dead_root(root);
76dda93c6ae2c1 Yan, Zheng 2009-09-21 289 }
78c52d9eb6b7ac Josef Bacik 2019-02-06 290 }
76dda93c6ae2c1 Yan, Zheng 2009-09-21 291
76dda93c6ae2c1 Yan, Zheng 2009-09-21 292 btrfs_free_path(path);
76dda93c6ae2c1 Yan, Zheng 2009-09-21 293 return err;
76dda93c6ae2c1 Yan, Zheng 2009-09-21 294 }
76dda93c6ae2c1 Yan, Zheng 2009-09-21 295

:::::: The code at line 259 was first introduced by commit
:::::: 886322e8e787604731e782d36c34327a8970bda9 btrfs: Use PTR_ERR_OR_ZERO

:::::: TO: Sachin Kamat <sachin.kamat@xxxxxxxxxx>
:::::: CC: Josef Bacik <jbacik@xxxxxx>

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