Enhancement: add uuid

"Usually, it is used 128-bits UUID for serial number. Why do you use
__le32 as volume_serial_number?"
>From Vyacheslav Dubeyko.

I added an uuid facility for the serial number.
And sync with kernel/include/linux/f2fs_fs.h.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/README b/README
index c0be658..c7b4a31 100644 (file)
--- a/README
+++ b/README
@@ -4,6 +4,12 @@ F2FS format utilility
 To use f2fs filesystem, you should format the storage partition
 with this utilility. Otherwise, you cannot mount f2fs.
 
+Before compilation
+------------------
+
+Your should install the following packages.
+ - libuuid-devel or uuid-dev
+
 Initial compilation
 -------------------
 

diff --git a/configure.ac b/configure.ac
index fd7272d..2a0c15f 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -11,6 +11,10 @@ AC_CONFIG_HEADERS([config.h])
 AC_PROG_CC
 
 # Checks for libraries.
+AC_CHECK_LIB([uuid], [uuid_generate],
+       [AC_DEFINE([HAVE_LIBUUID], 1,
+         [Define to 1 if you have the 'uuid' library (-luuid).])],
+       [AC_MSG_ERROR([UUID library not found])])
 
 # Checks for header files.
 AC_CHECK_HEADERS([fcntl.h mntent.h stdlib.h string.h sys/ioctl.h sys/mount.h unistd.h])

diff --git a/mkfs/Makefile.am b/mkfs/Makefile.am
index f47c1ec..b5a6cd2 100644 (file)
--- a/mkfs/Makefile.am
+++ b/mkfs/Makefile.am
@@ -1,5 +1,6 @@
 ## Makefile.am
 
 AM_CFLAGS = -Wall
+LDADD = -luuid
 bin_PROGRAMS = mkfs.f2fs
 mkfs_f2fs_SOURCES = f2fs_format.c f2fs_format.h

diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
index 7d4dad2..84796c1 100644 (file)
--- a/mkfs/f2fs_format.c
+++ b/mkfs/f2fs_format.c
@@ -24,6 +24,7 @@
 #include <linux/hdreg.h>
 #include <time.h>
 #include <linux/fs.h>
+#include <uuid/uuid.h>
 
 #include "f2fs_format.h"
 
@@ -561,7 +562,7 @@ static int f2fs_prepare_super_block(void)
                        / f2fs_params.segs_per_sec);
 
        super_block.segment_count_main = cpu_to_le32(
-                       le32_to_cpu(super_block.section_count) * 
+                       le32_to_cpu(super_block.section_count) *
                        f2fs_params.segs_per_sec);
 
        if ((le32_to_cpu(super_block.segment_count_main) - 2) <
@@ -574,7 +575,7 @@ static int f2fs_prepare_super_block(void)
        }
 
        super_block.failure_safe_block_distance = 0;
-       super_block.volume_serial_number = 0;
+       uuid_generate(super_block.uuid);
 
        ASCIIToUNICODE(super_block.volume_name, f2fs_params.vol_label);
 
@@ -582,7 +583,7 @@ static int f2fs_prepare_super_block(void)
        super_block.meta_ino = cpu_to_le32(2);
        super_block.root_ino = cpu_to_le32(3);
 
-       total_zones = ((le32_to_cpu(super_block.segment_count_main) - 1) / 
+       total_zones = ((le32_to_cpu(super_block.segment_count_main) - 1) /
                        f2fs_params.segs_per_sec) /
                        f2fs_params.secs_per_zone;
        if (total_zones <= 6) {
@@ -842,7 +843,7 @@ static int8_t f2fs_write_check_point_pack(void)
        SET_SUM_TYPE((&sum->footer), SUM_TYPE_DATA);
 
        sum->entries[0].nid = super_block.root_ino;
-       sum->entries[0].bidx = 0;
+       sum->entries[0].ofs_in_node = 0;
 
        cp_seg_blk_offset += blk_size_bytes;
        if (writetodisk(f2fs_params.fd, sum, cp_seg_blk_offset,

diff --git a/mkfs/f2fs_format.h b/mkfs/f2fs_format.h
index 31c075b..ec49d4d 100644 (file)
--- a/mkfs/f2fs_format.h
+++ b/mkfs/f2fs_format.h
@@ -56,6 +56,11 @@
 #define F2FS_CP_BLOCK_SIZE             (DEFAULT_SECTOR_SIZE * \
                                        DEFAULT_SECTORS_PER_BLOCK)
 
+/*
+ * For further optimization on multi-head logs, on-disk layout supports maximum
+ * 16 logs by default. The number, 16, is expected to cover all the cases
+ * enoughly.
+*/
 #define MAX_ACTIVE_LOGS        16
 #define MAX_ACTIVE_NODE_LOGS   8
 #define MAX_ACTIVE_DATA_LOGS   8
@@ -129,7 +134,7 @@ struct f2fs_super_block {
        __le32 root_ino;        /* Root directory inode number */
        __le32 node_ino;        /* node inode number */
        __le32 meta_ino;        /* meta inode number */
-       __le32 volume_serial_number;    /* VSN is optional field */
+       __u8 uuid[16];          /* 128-bit uuid for volume */
        __le16 volume_name[512];        /* Volume Name */
        __le32 extension_count;
        __u8 extension_list[F2FS_MAX_EXTENSION][8]; /* extension array */
@@ -273,6 +278,11 @@ enum {
 #define SIT_VBLOCK_MAP_SIZE    64
 #define SIT_ENTRY_PER_BLOCK (PAGE_CACHE_SIZE / sizeof(struct f2fs_sit_entry))
 
+/*
+ * Note that f2fs_sit_entry->vblocks has the following bit-field information.
+ * [15:10] : allocation type such as CURSEG_XXXX_TYPE
+ * [9:0] : valid block count
+ */
 struct f2fs_sit_entry {
        __le16 vblocks;
        __u8 valid_map[SIT_VBLOCK_MAP_SIZE];
@@ -283,13 +293,25 @@ struct f2fs_sit_block {
        struct f2fs_sit_entry entries[SIT_ENTRY_PER_BLOCK];
 } __attribute__((packed));
 
+/**
+ * For segment summary
+ *
+ * NOTE : For initializing fields, you must use set_summary
+ *
+ * - If data page, nid represents dnode's nid
+ * - If node page, nid represents the node page's nid.
+ *
+ * The ofs_in_node is used by only data page. It represents offset
+ * from node's page's beginning to get a data block address.
+ * ex) data_blkaddr = (block_t)(nodepage_start_address + ofs_in_node)
+ */
 struct f2fs_summary {
        __le32 nid;             /* parent node id */
        union {
                __u8 reserved[3];
                struct {
                        __u8 version;           /* node version number */
-                       __le16 bidx;            /* block index in parent node */
+                       __le16 ofs_in_node;     /* block index in parent node */
                } __attribute__((packed));
        };
 } __attribute__((packed));
@@ -360,9 +382,14 @@ struct f2fs_summary_block {
 /*
  * For directory operations
  */
-#define F2FS_NAME_LEN          8       /* 256 Unicode */
-#define NR_DENTRY_IN_BLOCK     214     /* the number of dentry in a block */
-#define MAX_DIR_HASH_DEPTH     63 /* MAX level for dir lookup */
+/* One directory entry slot covers 8bytes-long file name */
+#define F2FS_NAME_LEN          8
+
+/* the number of dentry in a block */
+#define NR_DENTRY_IN_BLOCK     214
+
+/* MAX level for dir lookup */
+#define MAX_DIR_HASH_DEPTH     63
 
 #define SIZE_OF_DIR_ENTRY      11      /* by byte */
 #define SIZE_OF_DENTRY_BITMAP  ((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \