[PATCH 1/3] fs: fat: Add fat filesystem partition volume label in local structure

From: ChenGuanqiao
Date: Wed Jan 17 2018 - 05:47:00 EST


Signed-off-by: ChenGuanqiao <chen.chenchacha@xxxxxxxxxxx>
---
fs/fat/fat.h | 5 +++++
fs/fat/inode.c | 6 ++++++
include/uapi/linux/msdos_fs.h | 2 ++
3 files changed, 13 insertions(+)

diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 8fc1093da47d..22cded6a2780 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -300,6 +300,11 @@ extern int fat_dir_empty(struct inode *dir);
extern int fat_subdirs(struct inode *dir);
extern int fat_scan(struct inode *dir, const unsigned char *name,
struct fat_slot_info *sinfo);
+extern int fat_get_volume_label_entry(struct inode *dir, struct buffer_head **bh,
+ struct msdos_dir_entry **de);
+extern int fat_add_volume_label_entry(struct inode*dir,
+ const unsigned char *name,
+ struct timespec *ts);
extern int fat_scan_logstart(struct inode *dir, int i_logstart,
struct fat_slot_info *sinfo);
extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index ffbbf0520d9e..40f1dd23e937 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -46,12 +46,14 @@ 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;
@@ -1461,12 +1463,16 @@ 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) {
diff --git a/include/uapi/linux/msdos_fs.h b/include/uapi/linux/msdos_fs.h
index a45d0754102e..90d2d6f3d908 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 _IOW('r', 0x15, __u8[11])

struct fat_boot_sector {
__u8 ignored[3]; /* Boot strap short or near jump */
--
2.11.0