[LTP] [PATCH v2] safe_macros.c: set umask to 0 within safe_mount

[Wei Gao]

When system's default umask is 0077, this will trigger following issues:
chdir01.c:100: TFAIL: nobody: chdir("subdir") returned unexpected value -1: EACCES (13)

Suggested-by: Martin Doucha <mdoucha@suse.cz>
Signed-off-by: Wei Gao <wegao@suse.com>
---
 doc/C-Test-API.asciidoc | 4 +++-
 lib/safe_macros.c       | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/doc/C-Test-API.asciidoc b/doc/C-Test-API.asciidoc
index 08a76c403..81067b12b 100644
--- a/doc/C-Test-API.asciidoc
+++ b/doc/C-Test-API.asciidoc
@@ -2460,7 +2460,9 @@ with 'open()' or 'creat()' etc, the mode specified as the last parameter *is
 not* the mode the file is created with. The mode depends on current 'umask()'
 settings which may clear some of the bits. If your test depends on specific
 file permissions you need either to change umask to 0 or 'chmod()' the file
-afterwards or use 'SAFE_TOUCH()' that does the 'chmod()' for you.
+afterwards or use 'SAFE_TOUCH()' that does the 'chmod()' for you. SAFE_MOUNT
+also does similar action such as setting umask(0) and then restoring the
+original value.
 
 2.2 access()
 ~~~~~~~~~~~~
diff --git a/lib/safe_macros.c b/lib/safe_macros.c
index 951e1b064..109268587 100644
--- a/lib/safe_macros.c
+++ b/lib/safe_macros.c
@@ -913,7 +913,10 @@ int safe_mount(const char *file, const int lineno, void (*cleanup_fn)(void),
 	 * the kernel's NTFS driver doesn't have proper write support.
 	 */
 	if (!filesystemtype || strcmp(filesystemtype, "ntfs")) {
+		mode_t old_umask = umask(0);
+
 		rval = mount(source, target, filesystemtype, mountflags, data);
+		umask(old_umask);
 		if (!rval)
 			return 0;
 	}
-- 
2.35.3