[kbuild-all] Re: [PATCH v6 7/7] kernfs: Replace per-fs rwsem with hashed ones.

Hi Imran, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on 6d9bd4ad4ca08b1114e814c2c42383b8b13be631] url: https://github.com/0day-ci/linux/commits/Imran-Khan/kernfs-Introduce-hash... base: 6d9bd4ad4ca08b1114e814c2c42383b8b13be631 config: hexagon-randconfig-r012-20220213 (https://download.01.org/0day-ci/archive/20220214/202202142322.OezS0EtW-lk...) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project ea071884b0cc7210b3cc5fe858f0e892a779a23b) 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/48eab913f80f1555d57b964ef7cdba17f... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Imran-Khan/kernfs-Introduce-hashed-mutexes-to-replace-global-kernfs_open_file_mutex/20220214-200700 git checkout 48eab913f80f1555d57b964ef7cdba17f5ec5d1f # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash fs/kernfs/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): >> fs/kernfs/dir.c:1619:7: warning: variable 'old_parent' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (!new_name) ^~~~~~~~~ fs/kernfs/dir.c:1653:50: note: uninitialized use occurs here up_write_kernfs_rwsem_rename_ns(kn, new_parent, old_parent); ^~~~~~~~~~ fs/kernfs/dir.c:1619:3: note: remove the 'if' if its condition is always false if (!new_name) ^~~~~~~~~~~~~~ fs/kernfs/dir.c:1612:6: warning: variable 'old_parent' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (kernfs_find_ns(new_parent, new_name, new_ns)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/kernfs/dir.c:1653:50: note: uninitialized use occurs here up_write_kernfs_rwsem_rename_ns(kn, new_parent, old_parent); ^~~~~~~~~~ fs/kernfs/dir.c:1612:2: note: remove the 'if' if its condition is always false if (kernfs_find_ns(new_parent, new_name, new_ns)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/kernfs/dir.c:1607:6: warning: variable 'old_parent' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if ((kn->parent == new_parent) && (kn->ns == new_ns) && ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/kernfs/dir.c:1653:50: note: uninitialized use occurs here up_write_kernfs_rwsem_rename_ns(kn, new_parent, old_parent); ^~~~~~~~~~ fs/kernfs/dir.c:1607:2: note: remove the 'if' if its condition is always false if ((kn->parent == new_parent) && (kn->ns == new_ns) && ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/kernfs/dir.c:1602:6: warning: variable 'old_parent' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (!kernfs_active(kn) || !kernfs_active(new_parent) || ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/kernfs/dir.c:1653:50: note: uninitialized use occurs here up_write_kernfs_rwsem_rename_ns(kn, new_parent, old_parent); ^~~~~~~~~~ fs/kernfs/dir.c:1602:2: note: remove the 'if' if its condition is always false if (!kernfs_active(kn) || !kernfs_active(new_parent) || ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> fs/kernfs/dir.c:1602:6: warning: variable 'old_parent' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized] if (!kernfs_active(kn) || !kernfs_active(new_parent) || ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/kernfs/dir.c:1653:50: note: uninitialized use occurs here up_write_kernfs_rwsem_rename_ns(kn, new_parent, old_parent); ^~~~~~~~~~ fs/kernfs/dir.c:1602:6: note: remove the '||' if its condition is always false if (!kernfs_active(kn) || !kernfs_active(new_parent) || ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> fs/kernfs/dir.c:1602:6: warning: variable 'old_parent' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized] if (!kernfs_active(kn) || !kernfs_active(new_parent) || ^~~~~~~~~~~~~~~~~~ fs/kernfs/dir.c:1653:50: note: uninitialized use occurs here up_write_kernfs_rwsem_rename_ns(kn, new_parent, old_parent); ^~~~~~~~~~ fs/kernfs/dir.c:1602:6: note: remove the '||' if its condition is always false if (!kernfs_active(kn) || !kernfs_active(new_parent) || ^~~~~~~~~~~~~~~~~~~~~ fs/kernfs/dir.c:1591:32: note: initialize the variable 'old_parent' to silence this warning struct kernfs_node *old_parent; ^ = NULL 6 warnings generated. vim +1619 fs/kernfs/dir.c fd7b9f7b9776b1 Tejun Heo 2013-11-28 1580 fd7b9f7b9776b1 Tejun Heo 2013-11-28 1581 /** fd7b9f7b9776b1 Tejun Heo 2013-11-28 1582 * kernfs_rename_ns - move and rename a kernfs_node 324a56e16e44ba Tejun Heo 2013-12-11 1583 * @kn: target node fd7b9f7b9776b1 Tejun Heo 2013-11-28 1584 * @new_parent: new parent to put @sd under fd7b9f7b9776b1 Tejun Heo 2013-11-28 1585 * @new_name: new name fd7b9f7b9776b1 Tejun Heo 2013-11-28 1586 * @new_ns: new namespace tag fd7b9f7b9776b1 Tejun Heo 2013-11-28 1587 */ 324a56e16e44ba Tejun Heo 2013-12-11 1588 int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, fd7b9f7b9776b1 Tejun Heo 2013-11-28 1589 const char *new_name, const void *new_ns) fd7b9f7b9776b1 Tejun Heo 2013-11-28 1590 { 3eef34ad7dc369 Tejun Heo 2014-02-07 1591 struct kernfs_node *old_parent; 3eef34ad7dc369 Tejun Heo 2014-02-07 1592 const char *old_name = NULL; fd7b9f7b9776b1 Tejun Heo 2013-11-28 1593 int error; fd7b9f7b9776b1 Tejun Heo 2013-11-28 1594 3eef34ad7dc369 Tejun Heo 2014-02-07 1595 /* can't move or rename root */ 3eef34ad7dc369 Tejun Heo 2014-02-07 1596 if (!kn->parent) 3eef34ad7dc369 Tejun Heo 2014-02-07 1597 return -EINVAL; 3eef34ad7dc369 Tejun Heo 2014-02-07 1598 48eab913f80f15 Imran Khan 2022-02-14 1599 down_write_kernfs_rwsem_rename_ns(kn, kn->parent, new_parent); 798c75a0d44cdb Greg Kroah-Hartman 2014-01-13 1600 d0ae3d4347ee02 Tejun Heo 2013-12-11 1601 error = -ENOENT; ea015218f2f7ac Eric W. Biederman 2015-05-13 @1602 if (!kernfs_active(kn) || !kernfs_active(new_parent) || ea015218f2f7ac Eric W. Biederman 2015-05-13 1603 (new_parent->flags & KERNFS_EMPTY_DIR)) d0ae3d4347ee02 Tejun Heo 2013-12-11 1604 goto out; d0ae3d4347ee02 Tejun Heo 2013-12-11 1605 fd7b9f7b9776b1 Tejun Heo 2013-11-28 1606 error = 0; adc5e8b58f4886 Tejun Heo 2013-12-11 1607 if ((kn->parent == new_parent) && (kn->ns == new_ns) && adc5e8b58f4886 Tejun Heo 2013-12-11 1608 (strcmp(kn->name, new_name) == 0)) 798c75a0d44cdb Greg Kroah-Hartman 2014-01-13 1609 goto out; /* nothing to rename */ fd7b9f7b9776b1 Tejun Heo 2013-11-28 1610 fd7b9f7b9776b1 Tejun Heo 2013-11-28 1611 error = -EEXIST; fd7b9f7b9776b1 Tejun Heo 2013-11-28 1612 if (kernfs_find_ns(new_parent, new_name, new_ns)) 798c75a0d44cdb Greg Kroah-Hartman 2014-01-13 1613 goto out; fd7b9f7b9776b1 Tejun Heo 2013-11-28 1614 324a56e16e44ba Tejun Heo 2013-12-11 1615 /* rename kernfs_node */ adc5e8b58f4886 Tejun Heo 2013-12-11 1616 if (strcmp(kn->name, new_name) != 0) { fd7b9f7b9776b1 Tejun Heo 2013-11-28 1617 error = -ENOMEM; 75287a677ba1be Andrzej Hajda 2015-02-13 1618 new_name = kstrdup_const(new_name, GFP_KERNEL); fd7b9f7b9776b1 Tejun Heo 2013-11-28 @1619 if (!new_name) 798c75a0d44cdb Greg Kroah-Hartman 2014-01-13 1620 goto out; 3eef34ad7dc369 Tejun Heo 2014-02-07 1621 } else { 3eef34ad7dc369 Tejun Heo 2014-02-07 1622 new_name = NULL; fd7b9f7b9776b1 Tejun Heo 2013-11-28 1623 } fd7b9f7b9776b1 Tejun Heo 2013-11-28 1624 fd7b9f7b9776b1 Tejun Heo 2013-11-28 1625 /* fd7b9f7b9776b1 Tejun Heo 2013-11-28 1626 * Move to the appropriate place in the appropriate directories rbtree. fd7b9f7b9776b1 Tejun Heo 2013-11-28 1627 */ c637b8acbe079e Tejun Heo 2013-12-11 1628 kernfs_unlink_sibling(kn); fd7b9f7b9776b1 Tejun Heo 2013-11-28 1629 kernfs_get(new_parent); 3eef34ad7dc369 Tejun Heo 2014-02-07 1630 3eef34ad7dc369 Tejun Heo 2014-02-07 1631 /* rename_lock protects ->parent and ->name accessors */ 3eef34ad7dc369 Tejun Heo 2014-02-07 1632 spin_lock_irq(&kernfs_rename_lock); 3eef34ad7dc369 Tejun Heo 2014-02-07 1633 3eef34ad7dc369 Tejun Heo 2014-02-07 1634 old_parent = kn->parent; adc5e8b58f4886 Tejun Heo 2013-12-11 1635 kn->parent = new_parent; 3eef34ad7dc369 Tejun Heo 2014-02-07 1636 3eef34ad7dc369 Tejun Heo 2014-02-07 1637 kn->ns = new_ns; 3eef34ad7dc369 Tejun Heo 2014-02-07 1638 if (new_name) { 3eef34ad7dc369 Tejun Heo 2014-02-07 1639 old_name = kn->name; 3eef34ad7dc369 Tejun Heo 2014-02-07 1640 kn->name = new_name; 3eef34ad7dc369 Tejun Heo 2014-02-07 1641 } 3eef34ad7dc369 Tejun Heo 2014-02-07 1642 3eef34ad7dc369 Tejun Heo 2014-02-07 1643 spin_unlock_irq(&kernfs_rename_lock); 3eef34ad7dc369 Tejun Heo 2014-02-07 1644 9561a8961c708f Tejun Heo 2014-02-10 1645 kn->hash = kernfs_name_hash(kn->name, kn->ns); c637b8acbe079e Tejun Heo 2013-12-11 1646 kernfs_link_sibling(kn); fd7b9f7b9776b1 Tejun Heo 2013-11-28 1647 3eef34ad7dc369 Tejun Heo 2014-02-07 1648 kernfs_put(old_parent); 75287a677ba1be Andrzej Hajda 2015-02-13 1649 kfree_const(old_name); 3eef34ad7dc369 Tejun Heo 2014-02-07 1650 fd7b9f7b9776b1 Tejun Heo 2013-11-28 1651 error = 0; ae34372eb8408b Tejun Heo 2014-01-10 1652 out: 48eab913f80f15 Imran Khan 2022-02-14 1653 up_write_kernfs_rwsem_rename_ns(kn, new_parent, old_parent); fd7b9f7b9776b1 Tejun Heo 2013-11-28 1654 return error; fd7b9f7b9776b1 Tejun Heo 2013-11-28 1655 } fd7b9f7b9776b1 Tejun Heo 2013-11-28 1656 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org