fs: Add nx_mount/nx_umount2 function

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

fs/mount/fs_mount.c

@@ -246,32 +246,23 @@ mount_findfs(FAR const struct fsmap_t *fstab, FAR const char *filesystemtype)
  ****************************************************************************/
 
 /****************************************************************************
- * Name: mount
+ * Name: nx_mount
  *
  * Description:
- *   mount() attaches the filesystem specified by the 'source' block device
+ *   nx_mount() is similar to the standard 'mount' interface except that is
- *   name into the root file system at the path specified by 'target.'
+ *   not a cancellation point and it does not modify the errno variable.
+ *
+ *   nx_mount() is an internal NuttX interface and should not be called from
+ *   applications.
  *
  * Returned Value:
- *   Zero is returned on success; -1 is returned on an error and errno is
+ *   Zero is returned on success; a negated value is returned on any failure.
- *   set appropriately:
- *
- *   EACCES A component of a path was not searchable or mounting a read-only
- *      filesystem was attempted without giving the MS_RDONLY flag.
- *   EBUSY 'source' is already  mounted.
- *   EFAULT One of the pointer arguments points outside the user address
- *      space.
- *   EINVAL 'source' had an invalid superblock.
- *   ENODEV 'filesystemtype' not configured
- *   ENOENT A pathname was empty or had a nonexistent component.
- *   ENOMEM Could not allocate a memory to copy filenames or data into.
- *   ENOTBLK 'source' is not a block device
  *
  ****************************************************************************/
 
-int mount(FAR const char *source, FAR const char *target,
+int nx_mount(FAR const char *source, FAR const char *target,
-          FAR const char *filesystemtype, unsigned long mountflags,
+             FAR const char *filesystemtype, unsigned long mountflags,
-          FAR const void *data)
+             FAR const void *data)
 {
 #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT) || defined(NODFS_SUPPORT)
 #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT)
@@ -283,14 +274,13 @@ int mount(FAR const char *source, FAR const char *target,
   struct inode_search_s desc;
 #endif
   void *fshandle;
-  int errcode;
   int ret;
 
   /* Verify required pointer arguments */
 
   DEBUGASSERT(target && filesystemtype);
 
-  /* Find the specified filesystem.  Try the block driver file systems first */
+  /* Find the specified filesystem. Try the block driver filesystems first */
 
 #ifdef BDFS_SUPPORT
   if (source != NULL &&
@@ -304,7 +294,7 @@ int mount(FAR const char *source, FAR const char *target,
           ferr("ERROR: Failed to find block based file system %s\n",
                filesystemtype);
 
-          errcode = ENODEV;
+          ret = -ENODEV;
           goto errout_with_inode;
         }
     }
@@ -321,7 +311,7 @@ int mount(FAR const char *source, FAR const char *target,
           ferr("ERROR: Failed to find MTD based file system %s\n",
                filesystemtype);
 
-          errcode = ENODEV;
+          ret = -ENODEV;
           goto errout_with_inode;
         }
     }
@@ -336,14 +326,13 @@ int mount(FAR const char *source, FAR const char *target,
     {
       ferr("ERROR: Failed to find block driver %s\n", source);
 
-      errcode = ENOTBLK;
+      ret = -ENOTBLK;
       goto errout;
     }
 
   ret = inode_semtake();
   if (ret < 0)
     {
-      errcode = -ret;
       goto errout_with_inode;
     }
 
@@ -369,7 +358,7 @@ int mount(FAR const char *source, FAR const char *target,
       if (INODE_IS_SPECIAL(mountpt_inode))
         {
           ferr("ERROR: target %s exists and is a special node\n", target);
-          errcode = -ENOTDIR;
+          ret = -ENOTDIR;
           inode_release(mountpt_inode);
           goto errout_with_semaphore;
         }
@@ -398,7 +387,6 @@ int mount(FAR const char *source, FAR const char *target,
            */
 
           ferr("ERROR: Failed to reserve inode for target %s\n", target);
-          errcode = -ret;
           goto errout_with_semaphore;
         }
     }
@@ -413,7 +401,7 @@ int mount(FAR const char *source, FAR const char *target,
       /* The filesystem does not support the bind operation ??? */
 
       ferr("ERROR: Filesystem does not support bind\n");
-      errcode = EINVAL;
+      ret = -EINVAL;
       goto errout_with_mountpt;
     }
 
@@ -453,7 +441,6 @@ int mount(FAR const char *source, FAR const char *target,
         }
 #endif
 
-      errcode = -ret;
       goto errout_with_mountpt;
     }
 
@@ -510,13 +497,51 @@ errout_with_inode:
 #endif
 
 errout:
-  set_errno(errcode);
+  return ret;
-  return ERROR;
 
 #else
   ferr("ERROR: No filesystems enabled\n");
-  set_errno(ENOSYS);
+  return -ENOSYS;
-  return ERROR;
 #endif /* BDFS_SUPPORT || MDFS_SUPPORT || NODFS_SUPPORT */
 }
 
+/****************************************************************************
+ * Name: mount
+ *
+ * Description:
+ *   mount() attaches the filesystem specified by the 'source' block device
+ *   name into the root file system at the path specified by 'target.'
+ *
+ * Returned Value:
+ *   Zero is returned on success; -1 is returned on an error and errno is
+ *   set appropriately:
+ *
+ *   EACCES A component of a path was not searchable or mounting a read-only
+ *      filesystem was attempted without giving the MS_RDONLY flag.
+ *   EBUSY 'source' is already  mounted.
+ *   EFAULT One of the pointer arguments points outside the user address
+ *      space.
+ *   EINVAL 'source' had an invalid superblock.
+ *   ENODEV 'filesystemtype' not configured
+ *   ENOENT A pathname was empty or had a nonexistent component.
+ *   ENOMEM Could not allocate a memory to copy filenames or data into.
+ *   ENOTBLK 'source' is not a block device
+ *
+ ****************************************************************************/
+
+int mount(FAR const char *source, FAR const char *target,
+          FAR const char *filesystemtype, unsigned long mountflags,
+          FAR const void *data)
+{
+  int ret;
+
+  ret = nx_mount(source, target, filesystemtype, mountflags, data);
+  if (ret < 0)
+    {
+      set_errno(-ret);
+      ret = ERROR;
+    }
+
+  return ret;
+}
+

fs/mount/fs_umount2.c

@@ -38,36 +38,32 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: umount2
+ * Name: nx_umount2
  *
  * Description:
- *   umount() detaches the filesystem mounted at the path specified by
+ *   nx_umount2() is similar to the standard 'umount2' interface except that
- *  'target.'
+ *   is not a cancellation point and it does not modify the errno variable.
+ *
+ *   nx_umount2() is an internal NuttX interface and should not be called
+ *   from applications.
  *
  * Returned Value:
- *   Zero is returned on success; -1 is returned on an error and errno is
+ *   Zero is returned on success; a negated value is returned on any failure.
- *   set appropriately:
- *
- *   EACCES A component of a path was not searchable or mounting a read-only
- *      filesystem was attempted without giving the MS_RDONLY flag.
- *   EBUSY The target could not be unmounted because it is busy.
- *   EFAULT The pointer argument points outside the user address space.
  *
  ****************************************************************************/
 
-int umount2(FAR const char *target, unsigned int flags)
+int nx_umount2(FAR const char *target, unsigned int flags)
 {
   FAR struct inode *mountpt_inode;
   FAR struct inode *blkdrvr_inode = NULL;
   struct inode_search_s desc;
-  int errcode = OK;
   int ret;
 
   /* Verify required pointer arguments */
 
   if (!target)
     {
-      errcode = EFAULT;
+      ret = -EFAULT;
       goto errout;
     }
 
@@ -78,7 +74,6 @@ int umount2(FAR const char *target, unsigned int flags)
   ret = inode_find(&desc);
   if (ret < 0)
     {
-      errcode = ENOENT;
       goto errout_with_search;
     }
 
@@ -91,7 +86,7 @@ int umount2(FAR const char *target, unsigned int flags)
 
   if (!INODE_IS_MOUNTPT(mountpt_inode))
     {
-      errcode = EINVAL;
+      ret = -EINVAL;
       goto errout_with_mountpt;
     }
 
@@ -103,7 +98,7 @@ int umount2(FAR const char *target, unsigned int flags)
     {
       /* The filesystem does not support the unbind operation ??? */
 
-      errcode = EINVAL;
+      ret = -EINVAL;
       goto errout_with_mountpt;
     }
 
@@ -117,7 +112,6 @@ int umount2(FAR const char *target, unsigned int flags)
   ret = inode_semtake();
   if (ret < 0)
     {
-      errcode = -ret;
       goto errout_with_mountpt;
     }
 
@@ -127,12 +121,11 @@ int umount2(FAR const char *target, unsigned int flags)
     {
       /* The inode is unhappy with the blkdrvr for some reason */
 
-      errcode = -ret;
       goto errout_with_semaphore;
     }
   else if (ret > 0)
     {
-      errcode = EBUSY;
+      ret = -EBUSY;
       goto errout_with_semaphore;
     }
 
@@ -171,7 +164,6 @@ int umount2(FAR const char *target, unsigned int flags)
 
       if (ret != OK && ret != -EBUSY)
         {
-          errcode = -ret;
           goto errout_with_mountpt;
         }
 
@@ -209,6 +201,37 @@ errout_with_search:
   RELEASE_SEARCH(&desc);
 
 errout:
-  set_errno(errcode);
+  return ret;
-  return ERROR;
+}
+
+/****************************************************************************
+ * Name: umount2
+ *
+ * Description:
+ *   umount() detaches the filesystem mounted at the path specified by
+ *  'target.'
+ *
+ * Returned Value:
+ *   Zero is returned on success; -1 is returned on an error and errno is
+ *   set appropriately:
+ *
+ *   EACCES A component of a path was not searchable or mounting a read-only
+ *      filesystem was attempted without giving the MS_RDONLY flag.
+ *   EBUSY The target could not be unmounted because it is busy.
+ *   EFAULT The pointer argument points outside the user address space.
+ *
+ ****************************************************************************/
+
+int umount2(FAR const char *target, unsigned int flags)
+{
+  int ret;
+
+  ret = nx_umount2(target, flags);
+  if (ret < 0)
+    {
+      set_errno(-ret);
+      ret = ERROR;
+    }
+
+  return ret;
 }

include/nuttx/fs/fs.h

@@ -188,6 +188,10 @@
 #define OPEN_SETFD(f)   ((f) | OPEN_MAGIC)
 #define OPEN_GETFD(r)   ((r) & OPEN_MASK)
 
+/* nx_umount() is equivalent to nx_umount2() with flags = 0 */
+
+#define umount(t)       umount2(t,0)
+
 /****************************************************************************
  * Public Type Definitions
  ****************************************************************************/
@@ -678,6 +682,46 @@ int register_mtdpartition(FAR const char *partition,
 int unregister_mtddriver(FAR const char *path);
 #endif
 
+/****************************************************************************
+ * Name: nx_mount
+ *
+ * Description:
+ *   nx_mount() is similar to the standard 'mount' interface except that is
+ *   not a cancellation point and it does not modify the errno variable.
+ *
+ *   nx_mount() is an internal NuttX interface and should not be called from
+ *   applications.
+ *
+ * Returned Value:
+ *   Zero is returned on success; a negated value is returned on any failure.
+ *
+ ****************************************************************************/
+
+#ifndef CONFIG_DISABLE_MOUNTPOINT
+int nx_mount(FAR const char *source, FAR const char *target,
+             FAR const char *filesystemtype, unsigned long mountflags,
+             FAR const void *data);
+#endif
+
+/****************************************************************************
+ * Name: nx_umount2
+ *
+ * Description:
+ *   nx_umount2() is similar to the standard 'umount2' interface except that
+ *   is not a cancellation point and it does not modify the errno variable.
+ *
+ *   nx_umount2() is an internal NuttX interface and should not be called
+ *   from applications.
+ *
+ * Returned Value:
+ *   Zero is returned on success; a negated value is returned on any failure.
+ *
+ ****************************************************************************/
+
+#ifndef CONFIG_DISABLE_MOUNTPOINT
+int nx_umount2(FAR const char *target, unsigned int flags);
+#endif
+
 /****************************************************************************
  * Name: files_initlist
  *

include/sys/mount.h

@@ -81,7 +81,7 @@
 #define MNT_EXPIRE      (1 << 2)
 #define UMOUNT_NOFOLLOW (0)
 
-/* mount() is equivalent to umount2() with flags = 0 */
+/* umount() is equivalent to umount2() with flags = 0 */
 
 #define umount(t)       umount2(t,0)