Changeset 8958a26 in mainline for uspace/lib/ext4

Timestamp:

2011-10-11T19:06:10Z (14 years ago)

Author:

Frantisek Princ <frantisek.princ@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

1a7756a

Parents:

acd869e

Message:

Extent reading (only with zero depth)

Location:

uspace/lib/ext4

Files:

• libext4_extent.c (modified) (1 diff)
• libext4_extent.h (modified) (1 diff)
• libext4_filesystem.c (modified) (1 diff)
• libext4_inode.c (modified) (1 diff)

uspace/lib/ext4/libext4_extent.c

@@ -39 +39 @@
 #include "libext4_extent.h"
 
+uint32_t ext4_extent_get_first_block(ext4_extent_t *extent)
+{
+        return uint32_t_le2host(extent->first_block);
+}
+
+uint16_t ext4_extent_get_block_count(ext4_extent_t *extent)
+{
+        return uint16_t_le2host(extent->block_count);
+}
+
+uint64_t ext4_extent_get_start(ext4_extent_t *extent)
+{
+        return ((uint64_t)uint16_t_le2host(extent->start_hi)) << 32 |
+                        ((uint64_t)uint32_t_le2host(extent->start_lo));
+
+}
+
 uint16_t ext4_extent_header_get_magic(ext4_extent_header_t *header)
 {

uspace/lib/ext4/libext4_extent.h

@@ -69 +69 @@
 
 #define EXT4_EXTENT_MAGIC       0xF30A
+#define EXT4_EXTENT_FIRST(header)       \
+                ((ext4_extent_t *) (((void *) (header)) + sizeof(ext4_extent_header_t)))
+
+extern uint32_t ext4_extent_get_first_block(ext4_extent_t *);
+extern uint16_t ext4_extent_get_block_count(ext4_extent_t *);
+extern uint64_t ext4_extent_get_start(ext4_extent_t *);
 
 extern uint16_t ext4_extent_header_get_magic(ext4_extent_header_t *);

uspace/lib/ext4/libext4_filesystem.c

@@ -301 +301 @@
         block_t *block;
 
-        // TODO extents
+        /* Handle inode using extents */
+        // TODO check "extents" feature in superblock ???
         if (ext4_inode_has_flag(inode, EXT4_INODE_FLAG_EXTENTS)) {
-                EXT4FS_DBG("Inode contains Extent");
-                // TODO
-                /*
                 current_block = ext4_inode_get_extent_block(inode, iblock);
                 *fblock = current_block;
                 return EOK;
-                */
 
         }

uspace/lib/ext4/libext4_inode.c

@@ -104 +104 @@
 uint32_t ext4_inode_get_extent_block(ext4_inode_t *inode, uint64_t idx)
 {
-        //ext4_extent_header_t *header = ext4_inode_get_extent_header(inode);
-        // TODO search required block
+        ext4_extent_header_t *header = ext4_inode_get_extent_header(inode);
+
+        if (ext4_extent_header_get_depth(header) == 0) {
+
+                ext4_extent_t *extent = EXT4_EXTENT_FIRST(header);
+
+                // TODO more effective searching?
+                for (uint16_t i = 0; i < ext4_extent_header_get_entries_count(header); ++i) {
+
+                        uint32_t first = ext4_extent_get_first_block(extent);
+                        uint16_t count = ext4_extent_get_block_count(extent);
+                        uint64_t block = 0;
+
+                        if ((idx >= first) && (idx < first + count)) {
+                                block = ext4_extent_get_start(extent) + idx;
+                                block -= ext4_extent_get_first_block(extent);
+                                return block;
+                        }
+                        // Go to the next extent
+                        ++extent;
+                }
+        }
+
+        // TODO binary search for depth > 0
+        EXT4FS_DBG("NOT IMPLEMENTED !!!");
         return 0;