tree: https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git work.dcache head: 08141fdc186755910b5bffc21a4325e2b673629f commit: 7cd7d43774879a6d7fc35662fb788ed8210dd09a [6/6] generic_ci_d_compare(): use shortname_storage config: csky-randconfig-002-20241223 (https://download.01.org/0day-ci/archive/20241223/202412232059.54ry0khI-lkp@xxxxxxxxx/config) compiler: csky-linux-gcc (GCC) 14.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241223/202412232059.54ry0khI-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202412232059.54ry0khI-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): fs/libfs.c: In function 'generic_ci_d_compare': >> fs/libfs.c:1819:17: warning: comparison of distinct pointer types lacks a cast [-Wcompare-distinct-pointer-types] 1819 | if (str == dentry->d_shortname.string) { | ^~ vim +1819 fs/libfs.c 1776 1777 #if IS_ENABLED(CONFIG_UNICODE) 1778 /** 1779 * generic_ci_d_compare - generic d_compare implementation for casefolding filesystems 1780 * @dentry: dentry whose name we are checking against 1781 * @len: len of name of dentry 1782 * @str: str pointer to name of dentry 1783 * @name: Name to compare against 1784 * 1785 * Return: 0 if names match, 1 if mismatch, or -ERRNO 1786 */ 1787 int generic_ci_d_compare(const struct dentry *dentry, unsigned int len, 1788 const char *str, const struct qstr *name) 1789 { 1790 const struct dentry *parent; 1791 const struct inode *dir; 1792 union shortname_store strbuf; 1793 struct qstr qstr; 1794 1795 /* 1796 * Attempt a case-sensitive match first. It is cheaper and 1797 * should cover most lookups, including all the sane 1798 * applications that expect a case-sensitive filesystem. 1799 * 1800 * This comparison is safe under RCU because the caller 1801 * guarantees the consistency between str and len. See 1802 * __d_lookup_rcu_op_compare() for details. 1803 */ 1804 if (len == name->len && !memcmp(str, name->name, len)) 1805 return 0; 1806 1807 parent = READ_ONCE(dentry->d_parent); 1808 dir = READ_ONCE(parent->d_inode); 1809 if (!dir || !IS_CASEFOLDED(dir)) 1810 return 1; 1811 1812 /* 1813 * If the dentry name is stored in-line, then it may be concurrently 1814 * modified by a rename. If this happens, the VFS will eventually retry 1815 * the lookup, so it doesn't matter what ->d_compare() returns. 1816 * However, it's unsafe to call utf8_strncasecmp() with an unstable 1817 * string. Therefore, we have to copy the name into a temporary buffer. 1818 */ > 1819 if (str == dentry->d_shortname.string) { 1820 strbuf = dentry->d_shortname; 1821 strbuf.string[len] = 0; 1822 str = strbuf.string; 1823 /* prevent compiler from optimizing out the temporary buffer */ 1824 barrier(); 1825 } 1826 qstr.len = len; 1827 qstr.name = str; 1828 1829 return utf8_strncasecmp(dentry->d_sb->s_encoding, name, &qstr); 1830 } 1831 EXPORT_SYMBOL(generic_ci_d_compare); 1832 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
