Changeset ce13577 in mainline

Timestamp:

2011-02-16T08:20:59Z (14 years ago)

Author:

Martin Sucha <sucha14@…>

Branches:

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

Children:

5352d72

Parents:

d241aae

Message:

Basic support for locating an inode

Location:

uspace/lib/ext2

Files:

• Makefile (modified) (1 diff)
• libext2.h (modified) (1 diff)
• libext2_filesystem.c (modified) (2 diffs)
• libext2_filesystem.h (modified) (2 diffs)
• libext2_inode.c (added)
• libext2_inode.h (added)

uspace/lib/ext2/Makefile

@@ -37 +37 @@
         libext2_filesystem.c \
         libext2_superblock.c \
-        libext2_block_group.c
+        libext2_block_group.c \
+        libext2_inode.c
 
 include $(USPACE_PREFIX)/Makefile.common

uspace/lib/ext2/libext2.h

@@ -39 +39 @@
 #include "libext2_superblock.h"
 #include "libext2_block_group.h"
+#include "libext2_inode.h"
 #include "libext2_filesystem.h"
 

uspace/lib/ext2/libext2_filesystem.c

@@ -37 +37 @@
 #include "libext2_superblock.h"
 #include "libext2_block_group.h"
+#include "libext2_inode.h"
 #include <errno.h>
 #include <libblock.h>
@@ -170 +171 @@
 
 /**
+ * Get a reference to inode
+ * 
+ * @param fs Pointer to filesystem information
+ * @param index The index number of the inode
+ * @param ref Pointer where to store pointer to inode reference
+ * 
+ * @return              EOK on success or negative error code on failure
+ */
+int ext2_filesystem_get_inode_ref(ext2_filesystem_t *fs, uint32_t index,
+    ext2_inode_ref_t **ref)
+{
+        int rc;
+        aoff64_t block_id;
+        uint32_t block_group;
+        uint32_t offset_in_group;
+        uint32_t inodes_per_group;
+        uint32_t inode_table_start;
+        uint16_t inode_size;
+        uint32_t block_size;
+        ext2_block_group_ref_t *bg_ref;
+        ext2_inode_ref_t *newref;
+        
+        newref = malloc(sizeof(ext2_inode_ref_t));
+        if (newref == NULL) {
+                return ENOMEM;
+        }
+        
+        inodes_per_group = ext2_superblock_get_inodes_per_group(fs->superblock);
+        
+        // inode numbers are 1-based
+        index -= 1;
+        block_group = index / inodes_per_group;
+        offset_in_group = index % inodes_per_group;
+        
+        rc = ext2_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
+        if (rc != EOK) {
+                free(newref);
+                return rc;
+        }
+        
+        inode_table_start = ext2_block_group_get_inode_table_first_block(
+            bg_ref->block_group);
+        
+        inode_size = ext2_superblock_get_inode_size(fs->superblock);
+        block_size = ext2_superblock_get_block_size(fs->superblock);
+        
+        block_id = inode_table_start + ((index * inode_size) / block_size);
+        
+        rc = block_get(&newref->block, fs->device, block_id, 0);
+        if (rc != EOK) {
+                free(newref);
+                return rc;
+        }
+        
+        newref->inode = newref->block->data + offset_in_group;
+        
+        *ref = newref;
+        
+        return EOK;
+}
+
+/**
+ * Free a reference to inode
+ * 
+ * @param ref Pointer to inode reference to free
+ * 
+ * @return              EOK on success or negative error code on failure
+ */
+int ext2_filesystem_put_inode_ref(ext2_inode_ref_t *ref)
+{
+        int rc;
+        
+        rc = block_put(ref->block);
+        free(ref);
+        
+        return rc;
+}
+
+/**
  * Finalize an instance of filesystem
  * 

uspace/lib/ext2/libext2_filesystem.h

@@ -40 +40 @@
 #include "libext2_superblock.h"
 #include "libext2_block_group.h"
+#include "libext2_inode.h"
 
 typedef struct ext2_filesystem {
@@ -56 +57 @@
     ext2_block_group_ref_t **);
 extern int ext2_filesystem_put_block_group_ref(ext2_block_group_ref_t *);
+extern int ext2_filesystem_get_inode_ref(ext2_filesystem_t *, uint32_t,
+    ext2_inode_ref_t **);
+extern int ext2_filesystem_put_inode_ref(ext2_inode_ref_t *);
 extern void ext2_filesystem_fini(ext2_filesystem_t *);