Changes between Version 36 and Version 37 of file_system

Timestamp:

Jan 14, 2016, 4:46:32 PM (10 years ago)

Author:

alain

Comment:

--

file_system

@@ -324 +324 @@
 The <string> argument is only used for debug.  It returns 0 on success. It returns 1 on error.
 
-
-
-//////////////////////////////////////////////////////////////////////////////////
-// The following function accesses directly the FS_INFO block on the block device, 
-// to update the "first_free_cluster" and "free_clusters_number" values,
-// using only the Fat-Descriptor single block buffer.
-// It return 0 on success.
-// It return 1 on error.
-//////////////////////////////////////////////////////////////////////////////////
-
-static unsigned int _update_fs_info();
-
-//////////////////////////////////////////////////////////////////////////////
-// The following function read a data field (from one to four bytes) 
-// from an unsigned char[] buffer, taking endianness into account. 
-// The analysed field is defined by the <offset> and <size> arguments.
-//////////////////////////////////////////////////////////////////////////////
-
-static unsigned int _read_entry( unsigned int    offset,
-                                 unsigned int    size,
-                                 unsigned char*  buffer,
-                                 unsigned int    little_indian );
-
-//////////////////////////////////////////////////////////////////////////////////
-// The following function returns the lba of first sector in DATA region 
-// from the cluster index. The cluster index must be larger than 2. 
-//////////////////////////////////////////////////////////////////////////////////
-
-static unsigned int _cluster_to_lba( unsigned int cluster );
-
-//////////////////////////////////////////////////////////////////////////////////
-// The following function returns in the "nb_entries" argument the number of files
-// (or directories) contained in a directory identified by the "inode " pointer.
-// It returns 0 on success.
-// It returns 1 on error.
-//////////////////////////////////////////////////////////////////////////////////
-
-static unsigned int _get_nb_entries( fat_inode_t*   inode,
-                                     unsigned int*  nb_entries );
-
-//////////////////////////////////////////////////////////////////////////////////
-// The following function search in the directory identified by the <parent>
-// inode pointer a child (file or directory) identified by its <name>.
-// It returns in the <inode> argument the searched child inode pointer.
-// If the searched name is not found in the Inode-Tree, the function accesses
-// the File-cache associated to the parent directory.
-// If the child exists on block device, the Inode-Tree is updated, and
-// a success code is returned.
-// If the file/dir does not exist on block device, a error code is returned.
-// It returns 0 if inode found.
-// It returns 1 if inode not found.
-// It returns 2 on error in cache access.
-//////////////////////////////////////////////////////////////////////////////////
-
-static unsigned int _get_child_from_parent( fat_inode_t*   parent,
-                                            char*          name,
-                                            fat_inode_t**  inode ); 
-
-/////////////////////////////////////////////////////////////////////////////////
-// For a file (or a directory) identified by the "pathname" argument, the
-// following function returns in the "inode" argument the inode pointer 
-// associated to the searched file (or directory), with code (0).
-// If the searched file (or directory) is not found, but the parent directory 
-// is found, it returns in the "inode" argument the pointer on the parent inode,
-// with code (1).  Finally, code (2) and code (3) are error codes.
-// Both the Inode-Tree and the involved Cache-Files are updated from the block
-// device in case of miss on one inode during the search in path.
-// Neither the Fat-Cache, nor the block device are updated.
-// It returns 0 if searched inode found
-// It returns 1 if searched inode not found but parent directory found
-// It returns 2 if searched inode not found and parent directory not found
-// It returns 3 if one name too long
-/////////////////////////////////////////////////////////////////////////////////
-
-static unsigned int _get_inode_from_path( char*          pathname,
-                                          fat_inode_t**  inode );
-
-//////////////////////////////////////////////////////////////////////////////////
-// The following function checks if node "a" is an ancestor of inode "b".
-// It returns 0 on failure.
-// It returns 1 otherwise.
-//////////////////////////////////////////////////////////////////////////////////
-
-static unsigned int _is_ancestor( fat_inode_t* a,
-                                  fat_inode_t* b);
+=== __unsigned int '''_update_fs_info()'''__ ===
+This function accesses directly the FS_INFO block on the block device, to update the "first_free_cluster" and "free_clusters_number" values, using only the Fat-Descriptor single block buffer.
+It return 0 on success. It return 1 on error.
+
+=== __unsigned int '''_read_entry'''( unsigned int offset , unsigned int size , unsigned char*  buffer , unsigned int little_indian )__ ===
+This function read a data field (one to four bytes) from an unsigned char[] <buffer>, taking endianness into account. 
+The analysed field is defined by the <offset> and <size> arguments.
+
+=== __unsigned int '''_cluster_to_lba'''( unsigned int cluster )__ ===
+This function returns the lba (logic block address in DATA region)  from the <cluster> index. Exit if the cluster value is smaller than 2. 
+
+=== __unsigned int '''_get_nb_entries'''( fat_inode_t* inode , unsigned int* nb_entries )__ ===
+This function returns in the <nb_entries> argument the number of entries  contained in a directory identified by the <inode> pointer. It returns 0 on success. It returns 1 on error. 
+
+=== __unsigned int '''_get_child_from_parent'''( fat_inode_t* parent , char* name , fat_inode_t**  inode )__ === 
+This function search in the directory identified by the <parent> inode pointer a child (file or directory) identified by its <name>.
+It returns in the <inode> argument the searched child inode pointer.
+If the searched name is not found in the Inode-Tree, the function accesses the File-cache associated to the parent directory.
+If the child exists on block device, the Inode-Tree is updated, and a success code is returned.
+If the file/dir does not exist on block device, a error code is returned.
+It returns 0 if inode found. It returns 1 if inode not found. It returns 2 in case of error in cache access.
+
+=== __unsigned int '''_get_inode_from_path'''( char* pathname , fat_inode_t**  inode )__ ===
+For a file (or a directory) identified by the <pathname> argument, this function returns in the <inode> argument the inode pointer associated to the searched file (or directory), with code (0).
+If the searched file (or directory) is not found, but the parent directory is found, it returns in the <inode> argument the pointer on the parent inode, with code (1).  Code (2) and code (3) are error codes. Both the Inode-Tree and the involved Cache-Files are updated from the block device in case of miss on one inode during the search. Neither the Fat-Cache, nor the block device are updated.
+It returns 0 if searched inode found  It returns 1 if searched inode not found but parent directory found. It returns 2 if searched inode not found and parent directory not found. It returns 3 if one name too long
+
+=== __unsigned int '''_is_ancestor'''( fat_inode_t* a , fat_inode_t* b )__ ===;
+The following function checks if inode <a> is an ancestor of inode <b>.
+It returns 0 on failure. It returns 1 otherwise.
+
+
+
 
 //////////////////////////////////////////////////////////////////////////////////