Changeset 656 for trunk/kernel/fs/vfs.h

Timestamp:

Dec 6, 2019, 12:07:51 PM (4 years ago)

Author:

alain

Message:

Fix several bugs in the FATFS and in the VFS,
related to the creation of big files requiring
more than 4 Kbytes (one cluster) on device.

File:

• trunk/kernel/fs/vfs.h (modified) (4 diffs)

trunk/kernel/fs/vfs.h

@@ -602 +602 @@
  *    and synchronously update the IOC device).
  * 2. It set the "size", and "extend" fields in child inode descriptor.
+ *    The size is 4096 for a directory, the size is 0 for a file.
  * 3. It updates the parent directory mapper to introduce the new child,
  *    and synchronously update the IOC device.
@@ -660 +661 @@
  * account the offset in <file_xp>. The transfer direction is defined by <to_buffer>.
  * It is called by the sys_read() and sys_write() functions.
+ * - for a read, it checks the actual file size (registered in the inode descriptor),
+ *   against the (offset + count), and moves only the significant bytes.
+ * - for a write, it updates the the file size in inode descriptor if required.
+ * In case of write to the mapper, the "inode.size" field is updated as required.
  ******************************************************************************************
  * @ to_buffer : mapper -> buffer if true / buffer -> mapper if false. 
  * @ file_xp   : extended pointer on the remote file descriptor.
  * @ buffer    : user space pointer on buffer (can be physically distributed).
- * @ size      : requested number of bytes from offset.
+ * @ count     : requested number of bytes from offset.
  * @ returns number of bytes actually moved if success / -1 if error.
  *****************************************************************************************/
-int vfs_user_move( bool_t   to_buffer,
-                   xptr_t   file_xp, 
-                   void   * buffer,
-                   uint32_t size );
+uint32_t vfs_user_move( bool_t   to_buffer,
+                        xptr_t   file_xp, 
+                        void   * buffer,
+                        uint32_t count );
 
 /****************************************************************************************** 
@@ -745 +750 @@
  *    to the file, and removes these pages from the dirty list, using an RPC if required.
  * 2) It updates the file size in all parent directory mapper(s), and update the modified
- *    pages on the block device, using RPCs if required.
+ *    pages on the block device, using RPCs if required, only if the size is modified.
  * 3) All entries in the fd_array copies are directly reset by the calling thread,
  *    using remote accesses. 
@@ -895 +900 @@
  * argument to/from the IOC device from/to the mapper, as defined by the <cmd_type>.
  * Depending on the file system type, it calls the proper, FS specific function.
- * It is used in case of MISS on the mapper, or when a dirty page in the mapper must
- * be updated in the File System.
- * The mapper pointer is obtained from the page descriptor.
+ * It is used in case of MISS on the mapper (read), or when a dirty page in the mapper
+ * must be updated in the File System (write).
+ * The mapper pointer, and the page index in file are obtained from the page descriptor.
  * It can be executed by any thread running in any cluster.
  * This function does NOT take any lock.