[PATCH v2 3/3] ntdll: Stop using chdir() in nt_to_unix_file_name().

[Brendan Shanks]

From: Brendan Shanks

---
 dlls/ntdll/unix/file.c | 39 ++++++++++++++++++---------------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/dlls/ntdll/unix/file.c b/dlls/ntdll/unix/file.c
index f3c8039be2b..a475fcc3225 100644
--- a/dlls/ntdll/unix/file.c
+++ b/dlls/ntdll/unix/file.c
@@ -2877,7 +2877,7 @@ NTSTATUS WINAPI NtQueryDirectoryFile( HANDLE handle, HANDLE event, PIO_APC_ROUTI
  * The file found is appended to unix_name at pos.
  * There must be at least MAX_DIR_ENTRY_LEN+2 chars available at pos.
  */
-static NTSTATUS find_file_in_dir( char *unix_name, int pos, const WCHAR *name, int length,
+static NTSTATUS find_file_in_dir( int root_fd, char *unix_name, int pos, const WCHAR *name, int length,
                                   BOOLEAN check_case )
 {
     WCHAR buffer[MAX_DIR_ENTRY_LEN];
@@ -2885,7 +2885,7 @@ static NTSTATUS find_file_in_dir( char *unix_name, int pos, const WCHAR *name, i
     DIR *dir;
     struct dirent *de;
     struct stat st;
-    int ret;
+    int fd, ret;

/* try a shortcut for this directory */

@@ -2894,7 +2894,7 @@ static NTSTATUS find_file_in_dir( char *unix_name, int pos, const WCHAR *name, i
     if (ret >= 0 && ret <= MAX_DIR_ENTRY_LEN)
     {
         unix_name[pos + ret] = 0;
-        if (!stat( unix_name, &st )) return STATUS_SUCCESS;
+        if (!fstatat( root_fd, unix_name, &st, 0 )) return STATUS_SUCCESS;
     }
     if (check_case) goto not_found;  /* we want an exact match */

@@ -2908,14 +2908,14 @@ static NTSTATUS find_file_in_dir( char *unix_name, int pos, const WCHAR *name, i
     is_name_8_dot_3 = is_name_8_dot_3 && length >= 8 && name[4] == '~';
 #endif

-    if (!is_name_8_dot_3 && !get_dir_case_sensitivity( AT_FDCWD, unix_name )) goto not_found;
+    if (!is_name_8_dot_3 && !get_dir_case_sensitivity( root_fd, unix_name )) goto not_found;

/* now look for it through the directory */

#ifdef VFAT_IOCTL_READDIR_BOTH
     if (is_name_8_dot_3)
     {
-        int fd = open( unix_name, O_RDONLY | O_DIRECTORY );
+        int fd = openat( root_fd, unix_name, O_RDONLY | O_DIRECTORY );
         if (fd != -1)
         {
             KERNEL_DIRENT kde[2];
@@ -2960,7 +2960,12 @@ static NTSTATUS find_file_in_dir( char *unix_name, int pos, const WCHAR *name, i
     }
 #endif /* VFAT_IOCTL_READDIR_BOTH */

-    if (!(dir = opendir( unix_name ))) return errno_to_status( errno );
+    if ((fd = openat( root_fd, unix_name, O_RDONLY )) == -1) return errno_to_status( errno );
+    if (!(dir = fdopendir( fd )))
+    {
+        close( fd );
+        return errno_to_status( errno );
+    }

unix_name[pos - 1] = '/';
     while ((de = readdir( dir )))
@@ -3512,8 +3517,8 @@ done:
  *
  * Helper for nt_to_unix_file_name
  */
-static NTSTATUS lookup_unix_name( const WCHAR *name, int name_len, char **buffer, int unix_len, int pos,
-                                  UINT disposition, BOOL is_unix )
+static NTSTATUS lookup_unix_name( int root_fd, const WCHAR *name, int name_len, char **buffer, int unix_len,
+                                  int pos, UINT disposition, BOOL is_unix )
 {
     static const WCHAR invalid_charsW[] = { INVALID_NT_CHARS, '/', 0 };
     NTSTATUS status;
@@ -3555,7 +3560,7 @@ static NTSTATUS lookup_unix_name( const WCHAR *name, int name_len, char **buffer
         char *p;
         unix_name[pos + 1 + ret] = 0;
         for (p = unix_name + pos ; *p; p++) if (*p == '\') *p = '/';
-        if (!stat( unix_name, &st ))
+        if (!fstatat( root_fd, unix_name, &st, 0 ))
         {
             if (disposition == FILE_CREATE) return STATUS_OBJECT_NAME_COLLISION;
             return STATUS_SUCCESS;
@@ -3589,7 +3594,7 @@ static NTSTATUS lookup_unix_name( const WCHAR *name, int name_len, char **buffer
             unix_name = *buffer = new_name;
         }

-        status = find_file_in_dir( unix_name, pos, name, end - name, is_unix );
+        status = find_file_in_dir( root_fd, unix_name, pos, name, end - name, is_unix );

/* if this is the last element, not finding it is not necessarily fatal */
         if (!name_len)
@@ -3726,7 +3731,7 @@ static NTSTATUS nt_to_unix_file_name_no_root( const UNICODE_STRING *nameW, char
     name += prefix_len;
     name_len -= prefix_len;

-    status = lookup_unix_name( name, name_len, &unix_name, unix_len, pos, disposition, is_unix );
+    status = lookup_unix_name( AT_FDCWD, name, name_len, &unix_name, unix_len, pos, disposition, is_unix );
     if (status == STATUS_SUCCESS || status == STATUS_NO_SUCH_FILE)
     {
         TRACE( "%s -> %s\n", debugstr_us(nameW), debugstr_a(unix_name) );
@@ -3753,7 +3758,7 @@ static NTSTATUS nt_to_unix_file_name_no_root( const UNICODE_STRING *nameW, char
 NTSTATUS nt_to_unix_file_name( const OBJECT_ATTRIBUTES *attr, char **name_ret, UINT disposition )
 {
     enum server_fd_type type;
-    int old_cwd, root_fd, needs_close;
+    int root_fd, needs_close;
     const WCHAR *name;
     char *unix_name;
     int name_len, unix_len;
@@ -3780,15 +3785,7 @@ NTSTATUS nt_to_unix_file_name( const OBJECT_ATTRIBUTES *attr, char **name_ret, U
         }
         else
         {
-            mutex_lock( &dir_mutex );
-            if ((old_cwd = open( ".", O_RDONLY )) != -1 && fchdir( root_fd ) != -1)
-            {
-                status = lookup_unix_name( name, name_len, &unix_name, unix_len, 1, disposition, FALSE );
-                if (fchdir( old_cwd ) == -1) chdir( "/" );
-            }
-            else status = errno_to_status( errno );
-            mutex_unlock( &dir_mutex );
-            if (old_cwd != -1) close( old_cwd );
+            status = lookup_unix_name( root_fd, name, name_len, &unix_name, unix_len, 1, disposition, FALSE );
             if (needs_close) close( root_fd );
         }
     }