The FAT filesystem volume label can be read with FAT_IOCTL_GET_VOLUME_LABEL and written with FAT_IOCTL_SET_VOLUME_LABEL.
Signed-off-by: Chen Guanqiao <[email protected]> --- fs/fat/fat.h | 1 + fs/fat/file.c | 51 +++++++++++++++++++++++++++++++++++++++++++ fs/fat/inode.c | 15 ++++++++++--- include/uapi/linux/msdos_fs.h | 2 ++ 4 files changed, 66 insertions(+), 3 deletions(-) diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 8fc1093da47d..204012c94421 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -86,6 +86,7 @@ struct msdos_sb_info { int dir_per_block; /* dir entries per block */ int dir_per_block_bits; /* log2(dir_per_block) */ unsigned int vol_id; /*volume ID*/ + char vol_label[11]; /*volume label*/ int fatent_shift; const struct fatent_operations *fatent_ops; diff --git a/fs/fat/file.c b/fs/fat/file.c index 4724cc9ad650..5d2990c44705 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -121,6 +121,53 @@ static int fat_ioctl_get_volume_id(struct inode *inode, u32 __user *user_attr) return put_user(sbi->vol_id, user_attr); } +static int fat_ioctl_get_volume_label(struct inode *inode, + u32 __user *user_attr) +{ + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); + u8 __user *vol_label = (u8 __user *)user_attr; + + return copy_to_user(vol_label, sbi->vol_label, sizeof(sbi->vol_label)); +} + +static int fat_ioctl_set_volume_label(struct inode *inode, + u32 __user *user_attr) +{ + struct buffer_head *bh; + struct fat_boot_sector *b; + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); + u8 __user *vol_label = (u8 __user *)user_attr; + u8 label[11]; + + if (copy_from_user(label, vol_label, sizeof(label))) + return -EFAULT; + + if (sb_rdonly(inode->i_sb)) + return -EFAULT; + + bh = sb_bread(inode->i_sb, 0); + if (bh == NULL) { + fat_msg(inode->i_sb, KERN_ERR, + "unable to read boot sector to write volume label"); + return -EFAULT; + } + + b = (struct fat_boot_sector *) bh->b_data; + + if (sbi->fat_bits == 32) + memcpy(b->fat32.vol_label, label, sizeof(label)); + else + memcpy(b->fat16.vol_label, label, sizeof(label)); + + mark_buffer_dirty(bh); + sync_dirty_buffer(bh); + brelse(bh); + + memcpy(sbi->vol_label, label, sizeof(sbi->vol_label)); + + return 0; +} + long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct inode *inode = file_inode(filp); @@ -133,6 +180,10 @@ long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return fat_ioctl_set_attributes(filp, user_attr); case FAT_IOCTL_GET_VOLUME_ID: return fat_ioctl_get_volume_id(inode, user_attr); + case FAT_IOCTL_GET_VOLUME_LABEL: + return fat_ioctl_get_volume_label(inode, user_attr); + case FAT_IOCTL_SET_VOLUME_LABEL: + return fat_ioctl_set_volume_label(inode, user_attr); default: return -ENOTTY; /* Inappropriate ioctl for device */ } diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 20a0a89eaca5..9991500c98af 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -45,12 +45,14 @@ struct fat_bios_param_block { u8 fat16_state; u32 fat16_vol_id; + u8 fat16_vol_label[11]; u32 fat32_length; u32 fat32_root_cluster; u16 fat32_info_sector; u8 fat32_state; u32 fat32_vol_id; + u8 fat32_vol_label[11]; }; static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; @@ -1460,12 +1462,16 @@ static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, bpb->fat16_state = b->fat16.state; bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); + memcpy(bpb->fat16_vol_label, b->fat16.vol_label, + sizeof(bpb->fat16_vol_label)); bpb->fat32_length = le32_to_cpu(b->fat32.length); bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); bpb->fat32_state = b->fat32.state; bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); + memcpy(bpb->fat32_vol_label, b->fat32.vol_label, + sizeof(bpb->fat32_vol_label)); /* Validate this looks like a FAT filesystem BPB */ if (!bpb->fat_reserved) { @@ -1723,11 +1729,14 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, brelse(fsinfo_bh); } - /* interpret volume ID as a little endian 32 bit integer */ - if (sbi->fat_bits == 32) + /* interpret volume ID and label as a little endian 32 bit integer */ + if (sbi->fat_bits == 32) { sbi->vol_id = bpb.fat32_vol_id; - else /* fat 16 or 12 */ + memcpy(sbi->vol_label, bpb.fat32_vol_label, sizeof(sbi->vol_label)); + } else { /* fat 16 or 12 */ sbi->vol_id = bpb.fat16_vol_id; + memcpy(sbi->vol_label, bpb.fat16_vol_label, sizeof(sbi->vol_label)); + } sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; diff --git a/include/uapi/linux/msdos_fs.h b/include/uapi/linux/msdos_fs.h index a45d0754102e..799f9a6cb99d 100644 --- a/include/uapi/linux/msdos_fs.h +++ b/include/uapi/linux/msdos_fs.h @@ -107,6 +107,8 @@ struct __fat_dirent { #define FAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, __u32) /*Android kernel has used 0x12, so we use 0x13*/ #define FAT_IOCTL_GET_VOLUME_ID _IOR('r', 0x13, __u32) +#define FAT_IOCTL_GET_VOLUME_LABEL _IOR('r', 0x14, __u8[11]) +#define FAT_IOCTL_SET_VOLUME_LABEL _IOR('r', 0x15, __u8[11]) struct fat_boot_sector { __u8 ignored[3]; /* Boot strap short or near jump */ -- 2.15.1
