test: Don't unmount not (yet) mounted system

When test suite tries to create a file for a new filesystem test case and fails,
the clean up of the exception tries to unmount the image, that has not yet been
mounted. When it happens, the fuse_mounted global variable is set to False and
inconveniently the test case tries to use sudo, so without this change the
admin of the machine gets an (annoying) email:

  Subject: *** SECURITY information for example.com ***

  example.com : Feb  5 19:43:47 : ... COMMAND=/bin/umount .../build-sandbox/persistent-data/mnt

and second run of the test cases on uncleaned build folder will ask for sudo
which is not what expected.

Besides that there is a double unmount calls during successfully run test case.

All of these due to over engineered Python try-except clause and people didn't
get it properly at all. The rule of thumb is that don't use more keywords than
try-except in the exception handling code. Nevertheless, here we adjust code
to be less intrusive to the initial logic behind that complex and unclear
constructions in the test case, although it adds a lot of lines of the code,
i.e. splits one exception handler to three, so on each step we know what
cleanup shall perform.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

test/py/tests/test_fs/conftest.py

@@ -270,9 +270,20 @@ def fs_obj_basic(request, u_boot_config):
 
         # 3GiB volume
         fs_img = mk_fs(u_boot_config, fs_type, 0xc0000000, '3GB')
+    except CalledProcessError as err:
+        pytest.skip('Creating failed for filesystem: ' + fs_type + '. {}'.format(err))
+        return
 
-        # Mount the image so we can populate it.
+    try:
         check_call('mkdir -p %s' % mount_dir, shell=True)
+    except CalledProcessError as err:
+        pytest.skip('Preparing mount folder failed for filesystem: ' + fs_type + '. {}'.format(err))
+        return
+    finally:
+        call('rm -f %s' % fs_img, shell=True)
+
+    try:
+        # Mount the image so we can populate it.
         mount_fs(fs_type, fs_img, mount_dir)
 
         # Create a subdirectory.
@@ -335,17 +346,14 @@ def fs_obj_basic(request, u_boot_config):
 	    % big_file, shell=True).decode()
         md5val.append(out.split()[0])
 
-        umount_fs(mount_dir)
     except CalledProcessError as err:
-        pytest.skip('Setup failed for filesystem: ' + fs_type + \
+        pytest.skip('Setup failed for filesystem: ' + fs_type + '. {}'.format(err))
-            '. {}'.format(err))
         return
     else:
         yield [fs_ubtype, fs_img, md5val]
     finally:
         umount_fs(mount_dir)
         call('rmdir %s' % mount_dir, shell=True)
-        if fs_img:
         call('rm -f %s' % fs_img, shell=True)
 
 #
@@ -378,9 +386,20 @@ def fs_obj_ext(request, u_boot_config):
 
         # 128MiB volume
         fs_img = mk_fs(u_boot_config, fs_type, 0x8000000, '128MB')
+    except CalledProcessError as err:
+        pytest.skip('Creating failed for filesystem: ' + fs_type + '. {}'.format(err))
+        return
 
-        # Mount the image so we can populate it.
+    try:
         check_call('mkdir -p %s' % mount_dir, shell=True)
+    except CalledProcessError as err:
+        pytest.skip('Preparing mount folder failed for filesystem: ' + fs_type + '. {}'.format(err))
+        return
+    finally:
+        call('rm -f %s' % fs_img, shell=True)
+
+    try:
+        # Mount the image so we can populate it.
         mount_fs(fs_type, fs_img, mount_dir)
 
         # Create a test directory
@@ -422,7 +441,6 @@ def fs_obj_ext(request, u_boot_config):
         md5val.append(out.split()[0])
 
         check_call('rm %s' % tmp_file, shell=True)
-        umount_fs(mount_dir)
     except CalledProcessError:
         pytest.skip('Setup failed for filesystem: ' + fs_type)
         return
@@ -431,7 +449,6 @@ def fs_obj_ext(request, u_boot_config):
     finally:
         umount_fs(mount_dir)
         call('rmdir %s' % mount_dir, shell=True)
-        if fs_img:
         call('rm -f %s' % fs_img, shell=True)
 
 #
@@ -460,10 +477,9 @@ def fs_obj_mkdir(request, u_boot_config):
         fs_img = mk_fs(u_boot_config, fs_type, 0x8000000, '128MB')
     except:
         pytest.skip('Setup failed for filesystem: ' + fs_type)
+        return
     else:
         yield [fs_ubtype, fs_img]
-    finally:
-        if fs_img:
     call('rm -f %s' % fs_img, shell=True)
 
 #
@@ -493,9 +509,20 @@ def fs_obj_unlink(request, u_boot_config):
 
         # 128MiB volume
         fs_img = mk_fs(u_boot_config, fs_type, 0x8000000, '128MB')
+    except CalledProcessError as err:
+        pytest.skip('Creating failed for filesystem: ' + fs_type + '. {}'.format(err))
+        return
 
-        # Mount the image so we can populate it.
+    try:
         check_call('mkdir -p %s' % mount_dir, shell=True)
+    except CalledProcessError as err:
+        pytest.skip('Preparing mount folder failed for filesystem: ' + fs_type + '. {}'.format(err))
+        return
+    finally:
+        call('rm -f %s' % fs_img, shell=True)
+
+    try:
+        # Mount the image so we can populate it.
         mount_fs(fs_type, fs_img, mount_dir)
 
         # Test Case 1 & 3
@@ -519,7 +546,6 @@ def fs_obj_unlink(request, u_boot_config):
         check_call('dd if=/dev/urandom of=%s/dir5/file1 bs=1K count=1'
                                     % mount_dir, shell=True)
 
-        umount_fs(mount_dir)
     except CalledProcessError:
         pytest.skip('Setup failed for filesystem: ' + fs_type)
         return
@@ -528,7 +554,6 @@ def fs_obj_unlink(request, u_boot_config):
     finally:
         umount_fs(mount_dir)
         call('rmdir %s' % mount_dir, shell=True)
-        if fs_img:
         call('rm -f %s' % fs_img, shell=True)
 
 #
@@ -559,11 +584,22 @@ def fs_obj_symlink(request, u_boot_config):
 
     try:
 
-        # 3GiB volume
+        # 1GiB volume
         fs_img = mk_fs(u_boot_config, fs_type, 0x40000000, '1GB')
+    except CalledProcessError as err:
+        pytest.skip('Creating failed for filesystem: ' + fs_type + '. {}'.format(err))
+        return
 
-        # Mount the image so we can populate it.
+    try:
         check_call('mkdir -p %s' % mount_dir, shell=True)
+    except CalledProcessError as err:
+        pytest.skip('Preparing mount folder failed for filesystem: ' + fs_type + '. {}'.format(err))
+        return
+    finally:
+        call('rm -f %s' % fs_img, shell=True)
+
+    try:
+        # Mount the image so we can populate it.
         mount_fs(fs_type, fs_img, mount_dir)
 
         # Create a subdirectory.
@@ -587,7 +623,6 @@ def fs_obj_symlink(request, u_boot_config):
             % medium_file, shell=True).decode()
         md5val.extend([out.split()[0]])
 
-        umount_fs(mount_dir)
     except CalledProcessError:
         pytest.skip('Setup failed for filesystem: ' + fs_type)
         return
@@ -596,5 +631,4 @@ def fs_obj_symlink(request, u_boot_config):
     finally:
         umount_fs(mount_dir)
         call('rmdir %s' % mount_dir, shell=True)
-        if fs_img:
         call('rm -f %s' % fs_img, shell=True)