Changes between Version 52 and Version 53 of file_system

Timestamp:

Feb 4, 2016, 12:04:18 PM (8 years ago)

Author:

alain

Comment:

--

file_system

@@ -194 +194 @@
 
 === __int '''_get_file_cache_buffer'''( fat_node_t* indoor , unsigned int cluster_id , unsigned int writable , fat_cache_desc_t** desc )__ ===
-This function returns in the <desc> argument a pointer on a buffer descriptor contained in a File_Cache. It can be used for a file or for a directory.
-The searched buffer is identified by the <inode> argument. The <cluster_id> argument is the buffer index in the File-Cache. The <writable> argument define the behaviour in case of miss in the File-Cache:
+This function returns in the <desc> argument a pointer on a buffer descriptor contained in a File_Cache, handling the possible miss.
+The searched file or directory is identified by the <inode> argument. The <cluster_id> argument is the buffer index in the File-Cache. The <writable> argument define the behaviour in case of miss in the File-Cache:
  * if [all clusters (from 0 to cluster_id) are already allocated in FAT] it scan the FAT to find the cluster index on device, and load the missing cluster in the File-Cache, marked as dirty if writable is set.
- * if [not writable and all clusters (from 0 to cluster_id) not allocated] it returns an error.
- * if [writable and all clusters (from 0 to cluster_id) not allocated], it allocates in FAT the required cluster, it updates the size in the inode and dentry (for a file), and load the missing cluster in the File-Cache, marked as dirty.
-This function is called by the _sys_fat_mmap() function, and by other FAT functions.
+ * if [writable and all clusters (from 0 to cluster_id) are not allocated], it allocates in FAT the required cluster, it updates the size attribute (for a file), or the is_dir attribute (for a directory), and load the missing cluster in the File-Cache, marked as dirty.
+ * if [not writable and all clusters (from 0 to cluster_id) are not allocated] it returns an error.
+This function is called by various FAT functions to access a file or a directory, but is also called by the _sys_fat_mmap() function.
 It does not take the FAT lock, that must be taken by the caller.