Fix nasa#580, improve FS_BASED mounts on VxWorks

The mount/unmount implementation was not really checking
for and handling this mapping type.

To be consistent with POSIX it should also create a directory
if it does not already exist.

src/os/inc/osapi-filesys.h

@@ -56,6 +56,16 @@ typedef struct
  * This mimics the behavior of a "FS_BASED" entry in the VolumeTable but is registered
  * at runtime.  It is intended to be called by the PSP/BSP prior to starting the application.
  *
+ * @note OSAL virtual mount points are required to be a single, non-empty top-level directory
+ * name.  Virtual path names always follow the form /<virt_mount_point>/<relative_path>/<file>.
+ * Only the relative path may be omitted/empty (i.e. /<virt_mount_point>/<file>) but the
+ * virtual mount point must be present and not an empty string.  In particular this means
+ * it is not possible to directly refer to files in the "root" of the native file system
+ * from OSAL.  However it is possible to create a virtual map to the root, such as by calling:
+ *
+ *      OS_FileSysAddFixedMap(&fs_id, "/", "/root");
+ *
+ *
  * @param[out]  filesys_id  A non-zero OSAL ID reflecting the file system
  * @param[in]   phys_path   The native system directory (an existing mount point)
  * @param[in]   virt_path   The virtual mount point of this filesystem

src/os/vxworks/src/os-impl-filesys.c

@@ -32,6 +32,7 @@
 #include "os-vxworks.h"
 
 #include "os-impl-filesys.h"
+#include "os-impl-dirs.h"
 #include "os-shared-filesys.h"
 #include "os-shared-idmap.h"
 
@@ -295,22 +296,62 @@ int32 OS_FileSysMountVolume_Impl(const OS_object_token_t *token)
     OS_filesys_internal_record_t *local;
     int32                         status;
     int                           fd;
+    struct stat                   stat_buf;
 
     local = OS_OBJECT_TABLE_GET(OS_filesys_table, *token);
 
     /*
-     * Calling open() on the physical device path
-     * mounts the device.
+     * For FS-based mounts, these are just a map to a some other
+     * directory in the filesystem.
+     *
+     * If it does exist then make sure it is actually a directory.
+     * If it does not exist then attempt to create it.
      */
-    fd = open(local->system_mountpt, O_RDONLY, 0644);
-    if (fd < 0)
+    if (local->fstype == OS_FILESYS_TYPE_FS_BASED)
     {
-        status = OS_ERROR;
+        if (stat(local->system_mountpt, &stat_buf) == 0)
+        {
+            if (S_ISDIR(stat_buf.st_mode))
+            {
+                /* mount point exists */
+                status = OS_SUCCESS;
+            }
+            else
+            {
+                OS_DEBUG("%s is not a directory\n", local->system_mountpt);
+                status = OS_FS_ERR_PATH_INVALID;
+            }
+        }
+        else
+        {
+            if (mkdir(local->system_mountpt, 0775) == 0)
+            {
+                /* directory created OK */
+                status = OS_SUCCESS;
+            }
+            else
+            {
+                OS_DEBUG("mkdir(%s): errno=%d\n", local->system_mountpt, errnoGet());
+                status = OS_FS_ERR_DRIVE_NOT_CREATED;
+            }
+        }
     }
     else
     {
-        status = OS_SUCCESS;
-        close(fd);
+        /*
+         * For all other (non-FS_BASED) filesystem types,
+         * Calling open() on the physical device path mounts the device.
+         */
+        fd = open(local->system_mountpt, O_RDONLY, 0644);
+        if (fd < 0)
+        {
+            status = OS_ERROR;
+        }
+        else
+        {
+            status = OS_SUCCESS;
+            close(fd);
+        }
     }
 
     return status;
@@ -333,26 +374,34 @@ int32 OS_FileSysUnmountVolume_Impl(const OS_object_token_t *token)
 
     local = OS_OBJECT_TABLE_GET(OS_filesys_table, *token);
 
-    /*
-    ** vxWorks uses an ioctl to unmount
-    */
-    fd = open(local->system_mountpt, O_RDONLY, 0644);
-    if (fd < 0)
+    if (local->fstype == OS_FILESYS_TYPE_FS_BASED)
     {
-        status = OS_ERROR;
+        /* unmount is a no-op on FS-based mounts - it is just a directory map */
+        status = OS_SUCCESS;
     }
     else
     {
-        if (ioctl(fd, FIOUNMOUNT, 0) < 0)
+        /*
+        ** vxWorks uses an ioctl to unmount
+        */
+        fd = open(local->system_mountpt, O_RDONLY, 0644);
+        if (fd < 0)
         {
             status = OS_ERROR;
         }
         else
         {
-            status = OS_SUCCESS;
-        }
+            if (ioctl(fd, FIOUNMOUNT, 0) < 0)
+            {
+                status = OS_ERROR;
+            }
+            else
+            {
+                status = OS_SUCCESS;
+            }
 
-        close(fd);
+            close(fd);
+        }
     }
 
     return status;

src/unit-test-coverage/vxworks/src/coveragetest-filesys.c

@@ -130,12 +130,38 @@ void Test_OS_FileSysMountVolume_Impl(void)
      * int32 OS_FileSysMountVolume_Impl (uint32 filesys_id)
      */
     OS_object_token_t token = UT_TOKEN_0;
+    struct OCS_stat   statbuf;
+
+    memset(&OS_filesys_table[0], 0, sizeof(OS_filesys_table[0]));
+    OS_filesys_table[0].fstype = OS_FILESYS_TYPE_NORMAL_DISK;
+    strcpy(OS_filesys_table[0].system_mountpt, "/ut");
 
     OSAPI_TEST_FUNCTION_RC(OS_FileSysMountVolume_Impl(&token), OS_SUCCESS);
 
     UT_SetDefaultReturnValue(UT_KEY(OCS_open), -1);
     OSAPI_TEST_FUNCTION_RC(OS_FileSysMountVolume_Impl(&token), OS_ERROR);
     UT_ClearForceFail(UT_KEY(OCS_open));
+
+    /* Additional cases for the FS_BASED handling */
+    OS_filesys_table[0].fstype = OS_FILESYS_TYPE_FS_BASED;
+
+    /* Mount dir does not exist but can be created */
+    UT_SetDefaultReturnValue(UT_KEY(OCS_stat), -1);
+    OSAPI_TEST_FUNCTION_RC(OS_FileSysMountVolume_Impl(&token), OS_SUCCESS);
+
+    /* Mount dir does not exist and cannot be created */
+    UT_SetDeferredRetcode(UT_KEY(OCS_mkdir), 1, -1);
+    OSAPI_TEST_FUNCTION_RC(OS_FileSysMountVolume_Impl(&token), OS_FS_ERR_DRIVE_NOT_CREATED);
+
+    /* Mount dir does exist but not a directory */
+    UT_ClearForceFail(UT_KEY(OCS_stat));
+    OSAPI_TEST_FUNCTION_RC(OS_FileSysMountVolume_Impl(&token), OS_FS_ERR_PATH_INVALID);
+
+    /* Mount dir does exist and is a directory */
+    memset(&statbuf, 0, sizeof(statbuf));
+    statbuf.st_mode = OCS_S_IFDIR;
+    UT_SetDataBuffer(UT_KEY(OCS_stat), &statbuf, sizeof(statbuf), false);
+    OSAPI_TEST_FUNCTION_RC(OS_FileSysMountVolume_Impl(&token), OS_SUCCESS);
 }
 
 void Test_OS_FileSysUnmountVolume_Impl(void)
@@ -145,6 +171,10 @@ void Test_OS_FileSysUnmountVolume_Impl(void)
      */
     OS_object_token_t token = UT_TOKEN_0;
 
+    memset(&OS_filesys_table[0], 0, sizeof(OS_filesys_table[0]));
+    OS_filesys_table[0].fstype = OS_FILESYS_TYPE_NORMAL_DISK;
+    strcpy(OS_filesys_table[0].system_mountpt, "/ut");
+
     OSAPI_TEST_FUNCTION_RC(OS_FileSysUnmountVolume_Impl(&token), OS_SUCCESS);
 
     UT_SetDefaultReturnValue(UT_KEY(OCS_open), -1);
@@ -154,6 +184,10 @@ void Test_OS_FileSysUnmountVolume_Impl(void)
     UT_SetDefaultReturnValue(UT_KEY(OCS_ioctl), -1);
     OSAPI_TEST_FUNCTION_RC(OS_FileSysUnmountVolume_Impl(&token), OS_ERROR);
     UT_ClearForceFail(UT_KEY(OCS_ioctl));
+
+    /* Additional cases for the FS_BASED handling (no op on unmount) */
+    OS_filesys_table[0].fstype = OS_FILESYS_TYPE_FS_BASED;
+    OSAPI_TEST_FUNCTION_RC(OS_FileSysUnmountVolume_Impl(&token), OS_SUCCESS);
 }
 
 void Test_OS_FileSysStatVolume_Impl(void)