Changeset 36bca8eb in mainline

Timestamp:

2011-02-13T18:55:00Z (13 years ago)

Author:

Martin Sucha <sucha14@…>

Branches:

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

Children:

e272949

Parents:

d5e2763

Message:

Add some more superblock members and function to read a superblock

Location:

uspace

Files:

• app/ext2info/ext2info.c (modified) (3 diffs)
• lib/ext2/Makefile (modified) (1 diff)
• lib/ext2/libext2.c (deleted)
• lib/ext2/libext2.h (modified) (1 diff)
• lib/ext2/libext2_filesystem.c (added)
• lib/ext2/libext2_superblock.c (added)

uspace/app/ext2info/ext2info.c

@@ -60 +60 @@
         char *dev_path;
         devmap_handle_t handle;
-        size_t block_size;
-        aoff64_t dev_nblocks;
-        uint8_t *data;
         ext2_superblock_t *superblock;
         
@@ -95 +92 @@
         }
 
-        rc = block_get_bsize(handle, &block_size);
-        if (rc != EOK) {
-                printf(NAME ": Error determining device block size.\n");
-                return 2;
-        }
-
-        rc = block_get_nblocks(handle, &dev_nblocks);
-        if (rc != EOK) {
-                printf(NAME ": Warning, failed to obtain block device size.\n");
-        }
-
-        data = malloc(block_size);
-        if (data == NULL) {
-                printf(NAME ": Error allocating data buffer of %" PRIuOFF64 " bytes", (aoff64_t) block_size);
-                block_fini(handle);
+        rc = ext2_superblock_read_direct(&superblock, handle);
+        if (rc != EOK)  {
+                printf(NAME ": Error reading superblock.\n");
                 return 3;
         }
-        
-        // TODO: don't assume device block size of 512 bytes
-        rc = block_read_direct(handle, 2, 1, data);
-        if (rc != EOK) {
-                printf(NAME ": Error reading block");
-                free(data);
-                return 3;
-        }
-        
-        superblock = (ext2_superblock_t *) data;
         
         printf("Superblock:\n");
@@ -133 +108 @@
         
         
-        free(data);
+        free(superblock);
 
         block_fini(handle);

uspace/lib/ext2/Makefile

@@ -31 +31 @@
 USPACE_PREFIX = ../..
 LIBRARY = libext2
+EXTRA_CFLAGS = -I$(LIBBLOCK_PREFIX)
 
 SOURCES = \
-        libext2.c
+        libext2_filesystem.c \
+        libext2_superblock.c
 
 include $(USPACE_PREFIX)/Makefile.common

uspace/lib/ext2/libext2.h

@@ -38 +38 @@
 
 #include <byteorder.h>
+#include <libblock.h>
 
 typedef struct ext2_superblock {
-        uint8_t unused[56];
-        uint16_t magic;
-} ext2_superblock_t;
+        uint8_t         unused[20];
+        uint32_t        first_block; // Block containing the superblock (either 0 or 1)
+        uint32_t        block_size_log2; // log_2(block_size)
+        int32_t         fragment_size_log2; // log_2(fragment size)
+        uint32_t        blocks_per_group; // Number of blocks in one block group
+        uint32_t        fragments_per_group; // Number of fragments per block group
+        uint32_t        inodes_per_group; // Number of inodes per block group
+        uint8_t         unused2[12];
+        uint16_t        magic; // Magic value
+} __attribute__ ((packed)) ext2_superblock_t;
+// TODO: add __attribute__((aligned(...)) for better performance?
+//       (it is necessary to ensure the superblock is correctly aligned then
+//        though)
 
-#define EXT2_SUPERBLOCK_MAGIC 0xEF53
+typedef struct ext2_filesystem {
+        devmap_handle_t         device;
+        ext2_superblock_t *     superblock;
+} ext2_filesystem_t;
 
-inline uint16_t ext2_superblock_get_magic(ext2_superblock_t *superblock);
+#define EXT2_SUPERBLOCK_MAGIC           0xEF53
+#define EXT2_SUPERBLOCK_SIZE            1024
+#define EXT2_SUPERBLOCK_OFFSET          1024
+#define EXT2_SUPERBLOCK_LAST_BYTE       (EXT2_SUPERBLOCK_OFFSET + \
+                                                                         EXT2_SUPERBLOCK_SIZE -1)
+
+inline uint16_t ext2_superblock_get_magic(ext2_superblock_t *sb);
+inline uint32_t ext2_superblock_get_first_block(ext2_superblock_t *sb);
+inline uint32_t ext2_superblock_get_block_size_log2(ext2_superblock_t *sb);
+inline uint32_t ext2_superblock_get_block_size(ext2_superblock_t *sb);
+inline int32_t  ext2_superblock_get_fragment_size_log2(ext2_superblock_t *sb);
+inline uint32_t ext2_superblock_get_fragment_size(ext2_superblock_t *sb);
+inline uint32_t ext2_superblock_get_blocks_per_group(ext2_superblock_t *sb);
+inline uint32_t ext2_superblock_get_fragments_per_group(ext2_superblock_t *sb);
+
+int ext2_superblock_read_direct(ext2_superblock_t **superblock,
+                                                                devmap_handle_t dev);
+
+int ext2_filesystem_init(ext2_filesystem_t *fs, devmap_handle_t dev);
+void ext2_filesystem_fini(ext2_filesystem_t *fs);
 
 #endif