Changes between Version 31 and Version 32 of file_system

Timestamp:

Jan 14, 2016, 1:06:37 PM (8 years ago)

Author:

alain

Comment:

--

file_system

@@ -254 +254 @@
  * GIET_FAT32_IO_ERROR
 
+=== __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. 
+The searched buffer is idenfified by the <inode> and <cluster_id> arguments. The <cluster_id> argument is the buffer index in the file. The <writable> argument define the behaviour in case of miss in 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.
+ * 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 all required clusters, it updates the size in the inode and dentry, and we allocate a buffer descriptor for the missing cluster, marked as dirty.
+This function is called by the _sys_fat_mmap() function, and by other FAT functions.
+It does not take the FAT lock, that must be taken by the caller.
+It returns GIET_FAT32_OK on success, and returns a negative value on error:
+ * GIET_FAT32_NOT_INITIALIZED
+ * GIET_FAT32_INVALID_ARG
+ * GIET_FAT32_IO_ERROR
+
 == 5) Internal functions ==