fs/ntfs3: Don't use uni1 uninitialized in ntfs_d_compare()

Clang warns:

  fs/ntfs3/namei.c:445:7: error: variable 'uni1' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
                  if (toupper(c1) != toupper(c2)) {
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
  ./include/linux/ctype.h:64:20: note: expanded from macro 'toupper'
  #define toupper(c) __toupper(c)
                    ^
  fs/ntfs3/namei.c:487:12: note: uninitialized use occurs here
          __putname(uni1);
                    ^~~~
  ./include/linux/fs.h:2789:65: note: expanded from macro '__putname'
  #define __putname(name)         kmem_cache_free(names_cachep, (void *)(name))
                                                                        ^~~~
  fs/ntfs3/namei.c:445:3: note: remove the 'if' if its condition is always false
                  if (toupper(c1) != toupper(c2)) {
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  fs/ntfs3/namei.c:434:7: error: variable 'uni1' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
                  if (!lm--) {
                      ^~~~~
  fs/ntfs3/namei.c:487:12: note: uninitialized use occurs here
          __putname(uni1);
                    ^~~~
  ./include/linux/fs.h:2789:65: note: expanded from macro '__putname'
  #define __putname(name)         kmem_cache_free(names_cachep, (void *)(name))
                                                                        ^~~~
  fs/ntfs3/namei.c:434:3: note: remove the 'if' if its condition is always false
                  if (!lm--) {
                  ^~~~~~~~~~~~
  fs/ntfs3/namei.c:430:22: note: initialize the variable 'uni1' to silence this warning
          struct cpu_str *uni1, *uni2;
                              ^
                              = NULL
  2 errors generated.

There is no point in calling __putname() in these particular error
paths, as there has been no corresponding __getname() call yet. Just
return directly in these blocks to clear up the warning.

Fixes: a3a956c78efa ("fs/ntfs3: Add option "nocase"")
Link: https://github.com/ClangBuiltLinux/linux/issues/1729
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c
index 315763e..5d3a6ce 100644 (file)
--- a/fs/ntfs3/namei.c
+++ b/fs/ntfs3/namei.c
@@ -431,10 +431,8 @@ static int ntfs_d_compare(const struct dentry *dentry, unsigned int len1,
 
        /* First try fast implementation. */
        for (;;) {
-               if (!lm--) {
-                       ret = len1 == len2 ? 0 : 1;
-                       goto out;
-               }
+               if (!lm--)
+                       return len1 == len2 ? 0 : 1;
 
                if ((c1 = *n1++) == (c2 = *n2++))
                        continue;
@@ -442,10 +440,8 @@ static int ntfs_d_compare(const struct dentry *dentry, unsigned int len1,
                if (c1 >= 0x80 || c2 >= 0x80)
                        break;
 
-               if (toupper(c1) != toupper(c2)) {
-                       ret = 1;
-                       goto out;
-               }
+               if (toupper(c1) != toupper(c2))
+                       return 1;
        }
 
        /*