Signed-off-by: ChenGuanqiao <chen.chencha...@foxmail.com>
---
fs/fat/dir.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 81cecbe6d7cf..63aab656c08e 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -881,6 +881,68 @@ static int fat_get_short_entry(struct inode *dir, loff_t
*pos,
return -ENOENT;
}
+static int fat_get_volume_label_entry(struct inode *dir, loff_t *pos,
+ struct buffer_head **bh,
+ struct msdos_dir_entry **de)
+{
+ while (fat_get_entry(dir, pos, bh, de) >= 0) {
+ if (((*de)->attr & ATTR_VOLUME) && (*de)->attr != ATTR_EXT)
+ return 0;
+ }
+ return -ENOENT;
+}
+
+int fat_scan_volume_label(struct inode *dir, struct buffer_head **bh,
+ struct msdos_dir_entry **de)
+{
+ loff_t offset = 0;
+
+ if (dir->i_ino != MSDOS_ROOT_INO)
+ return -EINVAL;
+
+ *bh = NULL;
+ *de = NULL;
+ while (fat_get_volume_label_entry(dir, &offset, bh, de) >= 0)
+ return 0;
+
+ return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(fat_scan_volume_label);
+
+int fat_add_volume_label_entry(struct inode *dir, const unsigned char *name,
+ struct timespec *ts)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
+ struct msdos_dir_entry de;
+ struct fat_slot_info sinfo;
+ __le16 time, date;
+ int err;
+
+ if (dir->i_ino != MSDOS_ROOT_INO)
+ return -EINVAL;
+
+ memcpy(de.name, name, MSDOS_NAME);
+ de.attr = ATTR_VOLUME;
+ de.lcase = 0;
+ fat_time_unix2fat(sbi, ts, &time, &date, NULL);
+ de.cdate = de.adate = 0;
+ de.ctime = 0;
+ de.ctime_cs = 0;
+ de.time = time;
+ de.date = date;
+ fat_set_start(&de, 0);
+ de.size = 0;
+
+ err = fat_add_entries(dir, &de, 1, &sinfo);
+ if (err)
+ return err;
+
+ dir->i_ctime = dir->i_mtime = *ts;
+
+ return fat_sync_inode(dir);
+}
+EXPORT_SYMBOL_GPL(fat_add_volume_label_entry);
+
/*
* The ".." entry can not provide the "struct fat_slot_info" information
* for inode, nor a usable i_pos. So, this function provides some information
--
2.11.0
