fs/btrfs/send.c:1925:27: warning: 'right_gen' may be used uninitialized in this function
From: kernel test robot
Date: Wed Feb 22 2023 - 19:39:43 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 8762069330316392331e693befd8a5b632833618
commit: 498581f33c9e60bfdfd28a8565e0ea81a1748aa3 btrfs: send: avoid extra b+tree searches when checking reference overrides
date: 9 days ago
config: x86_64-randconfig-a015 (https://download.01.org/0day-ci/archive/20230223/202302230825.LwCPauMj-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=498581f33c9e60bfdfd28a8565e0ea81a1748aa3
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 498581f33c9e60bfdfd28a8565e0ea81a1748aa3
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=x86_64 olddefconfig
make W=1 O=build_dir ARCH=x86_64 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/202302230825.LwCPauMj-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/send.c: In function 'get_cur_inode_state':
>> fs/btrfs/send.c:1925:27: warning: 'right_gen' may be used uninitialized in this function [-Wmaybe-uninitialized]
1925 | } else if (right_gen == gen) {
| ^
vim +/right_gen +1925 fs/btrfs/send.c
31db9f7c23fbf7 Alexander Block 2012-07-25 1886
498581f33c9e60 Filipe Manana 2023-01-11 1887 static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen,
498581f33c9e60 Filipe Manana 2023-01-11 1888 u64 *send_gen, u64 *parent_gen)
31db9f7c23fbf7 Alexander Block 2012-07-25 1889 {
31db9f7c23fbf7 Alexander Block 2012-07-25 1890 int ret;
31db9f7c23fbf7 Alexander Block 2012-07-25 1891 int left_ret;
31db9f7c23fbf7 Alexander Block 2012-07-25 1892 int right_ret;
31db9f7c23fbf7 Alexander Block 2012-07-25 1893 u64 left_gen;
31db9f7c23fbf7 Alexander Block 2012-07-25 1894 u64 right_gen;
9ed0a72e5b355d BingJing Chang 2022-08-12 1895 struct btrfs_inode_info info;
31db9f7c23fbf7 Alexander Block 2012-07-25 1896
9ed0a72e5b355d BingJing Chang 2022-08-12 1897 ret = get_inode_info(sctx->send_root, ino, &info);
31db9f7c23fbf7 Alexander Block 2012-07-25 1898 if (ret < 0 && ret != -ENOENT)
31db9f7c23fbf7 Alexander Block 2012-07-25 1899 goto out;
9ed0a72e5b355d BingJing Chang 2022-08-12 1900 left_ret = (info.nlink == 0) ? -ENOENT : ret;
9ed0a72e5b355d BingJing Chang 2022-08-12 1901 left_gen = info.gen;
498581f33c9e60 Filipe Manana 2023-01-11 1902 if (send_gen)
498581f33c9e60 Filipe Manana 2023-01-11 1903 *send_gen = ((left_ret == -ENOENT) ? 0 : info.gen);
31db9f7c23fbf7 Alexander Block 2012-07-25 1904
31db9f7c23fbf7 Alexander Block 2012-07-25 1905 if (!sctx->parent_root) {
31db9f7c23fbf7 Alexander Block 2012-07-25 1906 right_ret = -ENOENT;
31db9f7c23fbf7 Alexander Block 2012-07-25 1907 } else {
9ed0a72e5b355d BingJing Chang 2022-08-12 1908 ret = get_inode_info(sctx->parent_root, ino, &info);
31db9f7c23fbf7 Alexander Block 2012-07-25 1909 if (ret < 0 && ret != -ENOENT)
31db9f7c23fbf7 Alexander Block 2012-07-25 1910 goto out;
9ed0a72e5b355d BingJing Chang 2022-08-12 1911 right_ret = (info.nlink == 0) ? -ENOENT : ret;
9ed0a72e5b355d BingJing Chang 2022-08-12 1912 right_gen = info.gen;
498581f33c9e60 Filipe Manana 2023-01-11 1913 if (parent_gen)
498581f33c9e60 Filipe Manana 2023-01-11 1914 *parent_gen = ((right_ret == -ENOENT) ? 0 : info.gen);
31db9f7c23fbf7 Alexander Block 2012-07-25 1915 }
31db9f7c23fbf7 Alexander Block 2012-07-25 1916
31db9f7c23fbf7 Alexander Block 2012-07-25 1917 if (!left_ret && !right_ret) {
e938c8ad543cd5 Alexander Block 2012-07-28 1918 if (left_gen == gen && right_gen == gen) {
31db9f7c23fbf7 Alexander Block 2012-07-25 1919 ret = inode_state_no_change;
e938c8ad543cd5 Alexander Block 2012-07-28 1920 } else if (left_gen == gen) {
31db9f7c23fbf7 Alexander Block 2012-07-25 1921 if (ino < sctx->send_progress)
31db9f7c23fbf7 Alexander Block 2012-07-25 1922 ret = inode_state_did_create;
31db9f7c23fbf7 Alexander Block 2012-07-25 1923 else
31db9f7c23fbf7 Alexander Block 2012-07-25 1924 ret = inode_state_will_create;
31db9f7c23fbf7 Alexander Block 2012-07-25 @1925 } else if (right_gen == gen) {
31db9f7c23fbf7 Alexander Block 2012-07-25 1926 if (ino < sctx->send_progress)
31db9f7c23fbf7 Alexander Block 2012-07-25 1927 ret = inode_state_did_delete;
31db9f7c23fbf7 Alexander Block 2012-07-25 1928 else
31db9f7c23fbf7 Alexander Block 2012-07-25 1929 ret = inode_state_will_delete;
31db9f7c23fbf7 Alexander Block 2012-07-25 1930 } else {
31db9f7c23fbf7 Alexander Block 2012-07-25 1931 ret = -ENOENT;
31db9f7c23fbf7 Alexander Block 2012-07-25 1932 }
31db9f7c23fbf7 Alexander Block 2012-07-25 1933 } else if (!left_ret) {
31db9f7c23fbf7 Alexander Block 2012-07-25 1934 if (left_gen == gen) {
31db9f7c23fbf7 Alexander Block 2012-07-25 1935 if (ino < sctx->send_progress)
31db9f7c23fbf7 Alexander Block 2012-07-25 1936 ret = inode_state_did_create;
31db9f7c23fbf7 Alexander Block 2012-07-25 1937 else
31db9f7c23fbf7 Alexander Block 2012-07-25 1938 ret = inode_state_will_create;
31db9f7c23fbf7 Alexander Block 2012-07-25 1939 } else {
31db9f7c23fbf7 Alexander Block 2012-07-25 1940 ret = -ENOENT;
31db9f7c23fbf7 Alexander Block 2012-07-25 1941 }
31db9f7c23fbf7 Alexander Block 2012-07-25 1942 } else if (!right_ret) {
31db9f7c23fbf7 Alexander Block 2012-07-25 1943 if (right_gen == gen) {
31db9f7c23fbf7 Alexander Block 2012-07-25 1944 if (ino < sctx->send_progress)
31db9f7c23fbf7 Alexander Block 2012-07-25 1945 ret = inode_state_did_delete;
31db9f7c23fbf7 Alexander Block 2012-07-25 1946 else
31db9f7c23fbf7 Alexander Block 2012-07-25 1947 ret = inode_state_will_delete;
31db9f7c23fbf7 Alexander Block 2012-07-25 1948 } else {
31db9f7c23fbf7 Alexander Block 2012-07-25 1949 ret = -ENOENT;
31db9f7c23fbf7 Alexander Block 2012-07-25 1950 }
31db9f7c23fbf7 Alexander Block 2012-07-25 1951 } else {
31db9f7c23fbf7 Alexander Block 2012-07-25 1952 ret = -ENOENT;
31db9f7c23fbf7 Alexander Block 2012-07-25 1953 }
31db9f7c23fbf7 Alexander Block 2012-07-25 1954
31db9f7c23fbf7 Alexander Block 2012-07-25 1955 out:
31db9f7c23fbf7 Alexander Block 2012-07-25 1956 return ret;
31db9f7c23fbf7 Alexander Block 2012-07-25 1957 }
31db9f7c23fbf7 Alexander Block 2012-07-25 1958
:::::: The code at line 1925 was first introduced by commit
:::::: 31db9f7c23fbf7e95026143f79645de6507b583b Btrfs: introduce BTRFS_IOC_SEND for btrfs send/receive
:::::: TO: Alexander Block <ablock84@xxxxxxxxxxxxxx>
:::::: CC: Alexander Block <ablock84@xxxxxxxxxxxxxx>
--
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https://github.com/intel/lkp-tests