fs/btrfs/tree-log.c:6211:23: warning: 'last_range_start' may be used uninitialized in this function
From: kernel test robot
Date: Thu Apr 27 2023 - 20:15:39 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: d06f5a3f7140921ada47d49574ae6fa4de5e2a89
commit: f372463124df5f980de6ee0cd6000a3e43df0e01 btrfs: mark btrfs_assertfail() __noreturn
date: 10 days ago
config: i386-randconfig-a014 (https://download.01.org/0day-ci/archive/20230428/202304280811.DeQmh7Ky-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build):
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f372463124df5f980de6ee0cd6000a3e43df0e01
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout f372463124df5f980de6ee0cd6000a3e43df0e01
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=i386 olddefconfig
make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash fs/btrfs/
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/202304280811.DeQmh7Ky-lkp@xxxxxxxxx/
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
fs/btrfs/tree-log.c: In function 'log_delayed_deletions_incremental.isra':
>> fs/btrfs/tree-log.c:6211:23: warning: 'last_range_start' may be used uninitialized in this function [-Wmaybe-uninitialized]
6211 | ret = insert_dir_log_key(trans, log, path, key.objectid,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
6212 | first_dir_index, last_dir_index);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +/last_range_start +6211 fs/btrfs/tree-log.c
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6152
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6153 static int log_delayed_deletions_incremental(struct btrfs_trans_handle *trans,
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6154 struct btrfs_inode *inode,
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6155 struct btrfs_path *path,
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6156 const struct list_head *delayed_del_list,
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6157 struct btrfs_log_ctx *ctx)
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6158 {
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6159 struct btrfs_root *log = inode->root->log_root;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6160 const struct btrfs_delayed_item *curr;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6161 u64 last_range_start;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6162 u64 last_range_end = 0;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6163 struct btrfs_key key;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6164
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6165 key.objectid = btrfs_ino(inode);
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6166 key.type = BTRFS_DIR_INDEX_KEY;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6167 curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item,
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6168 log_list);
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6169
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6170 while (!list_entry_is_head(curr, delayed_del_list, log_list)) {
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6171 const struct btrfs_delayed_item *last = curr;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6172 u64 first_dir_index = curr->index;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6173 u64 last_dir_index;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6174 bool deleted_items = false;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6175 int ret;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6176
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6177 key.offset = curr->index;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6178 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6179 if (ret < 0) {
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6180 return ret;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6181 } else if (ret == 0) {
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6182 ret = batch_delete_dir_index_items(trans, inode, path, ctx,
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6183 delayed_del_list, curr,
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6184 &last);
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6185 if (ret)
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6186 return ret;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6187 deleted_items = true;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6188 }
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6189
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6190 btrfs_release_path(path);
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6191
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6192 /*
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6193 * If we deleted items from the leaf, it means we have a range
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6194 * item logging their range, so no need to add one or update an
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6195 * existing one. Otherwise we have to log a dir range item.
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6196 */
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6197 if (deleted_items)
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6198 goto next_batch;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6199
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6200 last_dir_index = last->index;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6201 ASSERT(last_dir_index >= first_dir_index);
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6202 /*
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6203 * If this range starts right after where the previous one ends,
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6204 * then we want to reuse the previous range item and change its
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6205 * end offset to the end of this range. This is just to minimize
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6206 * leaf space usage, by avoiding adding a new range item.
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6207 */
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6208 if (last_range_end != 0 && first_dir_index == last_range_end + 1)
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6209 first_dir_index = last_range_start;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6210
30b80f3ce0f9d5 Filipe Manana 2022-08-22 @6211 ret = insert_dir_log_key(trans, log, path, key.objectid,
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6212 first_dir_index, last_dir_index);
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6213 if (ret)
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6214 return ret;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6215
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6216 last_range_start = first_dir_index;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6217 last_range_end = last_dir_index;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6218 next_batch:
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6219 curr = list_next_entry(last, log_list);
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6220 }
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6221
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6222 return 0;
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6223 }
30b80f3ce0f9d5 Filipe Manana 2022-08-22 6224
:::::: The code at line 6211 was first introduced by commit
:::::: 30b80f3ce0f9d58ab8a2094922f3d54d2fd4f92e btrfs: use delayed items when logging a directory
:::::: TO: Filipe Manana <fdmanana@xxxxxxxx>
:::::: CC: David Sterba <dsterba@xxxxxxxx>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests