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-rw-r--r--fs/fat/dir.c9
-rw-r--r--fs/fat/fat.h1
-rw-r--r--fs/fat/inode.c9
3 files changed, 19 insertions, 0 deletions
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index aca191bd5f8f..65e174bd0651 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -754,6 +754,13 @@ static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
return ret;
}
+static int fat_ioctl_volume_id(struct inode *dir)
+{
+ struct super_block *sb = dir->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ return sbi->vol_id;
+}
+
static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
@@ -770,6 +777,8 @@ static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
short_only = 0;
both = 1;
break;
+ case VFAT_IOCTL_GET_VOLUME_ID:
+ return fat_ioctl_volume_id(inode);
default:
return fat_generic_ioctl(filp, cmd, arg);
}
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 66994f316e18..341f75373383 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -78,6 +78,7 @@ struct msdos_sb_info {
const void *dir_ops; /* Opaque; default directory operations */
int dir_per_block; /* dir entries per block */
int dir_per_block_bits; /* log2(dir_per_block) */
+ unsigned long vol_id; /* volume ID */
int fatent_shift;
struct fatent_operations *fatent_ops;
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 3ab841054d53..18727a4c5b44 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -1246,6 +1246,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
struct inode *root_inode = NULL, *fat_inode = NULL;
struct buffer_head *bh;
struct fat_boot_sector *b;
+ struct fat_boot_bsx *bsx;
struct msdos_sb_info *sbi;
u16 logical_sector_size;
u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
@@ -1390,6 +1391,8 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
goto out_fail;
}
+ bsx = (struct fat_boot_bsx *)(bh->b_data + FAT32_BSX_OFFSET);
+
fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
if (!IS_FSINFO(fsinfo)) {
fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
@@ -1405,8 +1408,14 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
}
brelse(fsinfo_bh);
+ } else {
+ bsx = (struct fat_boot_bsx *)(bh->b_data + FAT16_BSX_OFFSET);
}
+ /* interpret volume ID as a little endian 32 bit integer */
+ sbi->vol_id = (((u32)bsx->vol_id[0]) | ((u32)bsx->vol_id[1] << 8) |
+ ((u32)bsx->vol_id[2] << 16) | ((u32)bsx->vol_id[3] << 24));
+
sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;