[syslinux:master] FSUUID for ext2 filesystem

[syslinux-bot for Serj Kalichev]

Commit-ID:  7c5efd0977a567296573b09b6436b8ffbcd369ee
Gitweb:     http://www.syslinux.org/commit/7c5efd0977a567296573b09b6436b8ffbcd369ee
Author:     Serj Kalichev <serj.kalichev at gmail.com>
AuthorDate: Thu, 21 Nov 2013 10:44:15 +0400
Committer:  H. Peter Anvin <hpa at zytor.com>
CommitDate: Thu, 13 Mar 2014 19:58:33 -0700

FSUUID for ext2 filesystem

The ext2 filesystem supports volume UUID now.
The FSUUID variable can be set to kernel command line.
Patch is based on FSUUID for FAT patch.

Signed-off-by: Serj Kalichev <serj.kalichev at gmail.com>
Signed-off-by: H. Peter Anvin <hpa at zytor.com>

---
 core/fs/ext2/ext2.c    | 40 +++++++++++++++++++++++++++++++++++++++-
 core/fs/ext2/ext2_fs.h |  1 +
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/core/fs/ext2/ext2.c b/core/fs/ext2/ext2.c
index df0856f..76bd1d5 100644
--- a/core/fs/ext2/ext2.c
+++ b/core/fs/ext2/ext2.c
@@ -312,6 +312,9 @@ static int ext2_fs_init(struct fs_info *fs)
     sbi->s_first_data_block = sb.s_first_data_block;
     sbi->s_inode_size = sb.s_inode_size;
 
+    /* Volume UUID */
+    memcpy(sbi->s_uuid, sb.s_uuid, sizeof(sbi->s_uuid));
+
     /* Initialize the cache, and force block zero to all zero */
     cache_init(fs->fs_dev, fs->block_shift);
     cs = _get_cache_block(fs->fs_dev, 0);
@@ -321,6 +324,41 @@ static int ext2_fs_init(struct fs_info *fs)
     return fs->block_shift;
 }
 
+#define EXT2_UUID_LEN (4 + 4 + 1 + 4 + 1 + 4 + 1 + 4 + 1 + 4 + 4 + 4 + 1)
+static char *ext2_fs_uuid(struct fs_info *fs)
+{
+    char *uuid = NULL;
+
+    uuid = malloc(EXT2_UUID_LEN);
+    if (!uuid)
+	return NULL;
+
+    if (snprintf(uuid, EXT2_UUID_LEN,
+                  "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+	          EXT2_SB(fs)->s_uuid[0],
+	          EXT2_SB(fs)->s_uuid[1],
+	          EXT2_SB(fs)->s_uuid[2],
+	          EXT2_SB(fs)->s_uuid[3],
+	          EXT2_SB(fs)->s_uuid[4],
+	          EXT2_SB(fs)->s_uuid[5],
+	          EXT2_SB(fs)->s_uuid[6],
+	          EXT2_SB(fs)->s_uuid[7],
+	          EXT2_SB(fs)->s_uuid[8],
+	          EXT2_SB(fs)->s_uuid[9],
+	          EXT2_SB(fs)->s_uuid[10],
+	          EXT2_SB(fs)->s_uuid[11],
+	          EXT2_SB(fs)->s_uuid[12],
+	          EXT2_SB(fs)->s_uuid[13],
+	          EXT2_SB(fs)->s_uuid[14],
+	          EXT2_SB(fs)->s_uuid[15]
+	          ) < 0) {
+	free(uuid);
+	return NULL;
+    }
+
+    return uuid;
+}
+
 const struct fs_ops ext2_fs_ops = {
     .fs_name       = "ext2",
     .fs_flags      = FS_THISIND | FS_USEMEM,
@@ -336,5 +374,5 @@ const struct fs_ops ext2_fs_ops = {
     .readlink      = ext2_readlink,
     .readdir       = ext2_readdir,
     .next_extent   = ext2_next_extent,
-    .fs_uuid       = NULL,
+    .fs_uuid       = ext2_fs_uuid,
 };
diff --git a/core/fs/ext2/ext2_fs.h b/core/fs/ext2/ext2_fs.h
index 8adc9bb..803a995 100644
--- a/core/fs/ext2/ext2_fs.h
+++ b/core/fs/ext2/ext2_fs.h
@@ -277,6 +277,7 @@ struct ext2_sb_info {
     uint32_t s_groups_count;    /* Number of groups in the fs */
     uint32_t s_first_data_block;	/* First Data Block */
     int      s_inode_size;
+    uint8_t  s_uuid[16];	/* 128-bit uuid for volume */
 };
 
 static inline struct ext2_sb_info *EXT2_SB(struct fs_info *fs)