f2fs: expose extension_list sysfs entry
This patch adds a sysfs entry 'extension_list' to support
query/add/del item in extension list.
Query:
cat /sys/fs/f2fs/<device>/extension_list
Add:
echo 'extension' > /sys/fs/f2fs/<device>/extension_list
Del:
echo '!extension' > /sys/fs/f2fs/<device>/extension_list
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index 96c9bdb..d8c2414 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -21,6 +21,7 @@
#define F2FS_BLKSIZE 4096 /* support only 4KB block */
#define F2FS_BLKSIZE_BITS 12 /* bits for F2FS_BLKSIZE */
#define F2FS_MAX_EXTENSION 64 /* # of extension entries */
+#define F2FS_EXTENSION_LEN 8 /* max size of extension */
#define F2FS_BLK_ALIGN(x) (((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)
#define NULL_ADDR ((block_t)0) /* used as block_t addresses */
@@ -101,7 +102,7 @@
__u8 uuid[16]; /* 128-bit uuid for volume */
__le16 volume_name[MAX_VOLUME_NAME]; /* volume name */
__le32 extension_count; /* # of extensions below */
- __u8 extension_list[F2FS_MAX_EXTENSION][8]; /* extension array */
+ __u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
__le32 cp_payload;
__u8 version[VERSION_LEN]; /* the kernel version */
__u8 init_version[VERSION_LEN]; /* the initial kernel version */