Changes between Version 50 and Version 51 of file_system

Timestamp:

Feb 3, 2016, 8:00:15 PM (9 years ago)

Author:

alain

Comment:

--

file_system

@@ -61 +61 @@
 == 3) Implementation Notes
 
-=== __'''File / directory size'''__ ===
- For a file, the number of occupied clusters on block device can be directly obtained from the  <size>. The <size> attribute is a number of bytes stored on block device (in the directory entry), and copied in memory as a specific field in  the associated inode.
- For a directory, the size attribute must be set to 0. The number of occupied clusters on block device can be obtained from the <is_dir> field in the associated inode: This field is set to 0 for a file, and contain the number of occupied clusters, that cannot be zero, because a directory contains always the '.' and '..' entries.
-
-=== __'''File / directory names'''__ ===
+ '''File / directory size'''
+For a file, the number of occupied clusters on block device can be directly obtained from the  <size>. The <size> attribute is a number of bytes stored on block device (in the directory entry), and copied in memory as a specific field in  the associated inode.
+For a directory, the< size> attribute must be set to 0. The number of occupied clusters on block device can be obtained from the <is_dir> field in the associated inode: This field is set to 0 for a file, and contain the number of occupied clusters, that cannot be zero, because a directory contains always the '.' and '..' entries.
+
+ '''File / directory names'''
 This implementation supports the LFN (long file name) extension, up to 31 characters. Therefore, each file or directory contained in a parent directory occupies several 32 bytes directory entries:
- * short names (up to 13 characters) occupy 2 entries: one LFN and one NORMAL.
- * medium names (from 14 to 26 characters) occupy 3 entries: two LFN and one NORMAL.
- * large names (from 27 to 31 characters) occupy 4 entries: three LFN and one NORMAL.
+ * names up to 13 characters occupy 2 entries : one LFN and one NORMAL.
+ * names from 14 to 26 characters occupy 3 entries: two LFN and one NORMAL.
+ * names from 27 to 31 characters occupy 4 entries: three LFN and one NORMAL.
 When new names are created, a legal 8-3 SFN (Short File Name) alias is generated from the complete new name, and is stored in the NORMAL directory entry, to produce a legal FAT32 image. But this alias SFN is never used by the FAT32 library for file identification.