From: Anand Jain <anand.j...@oracle.com>
v1->v2:
This adds a new member label in the btrfs_root_item struct,
which uses 32 bytes of the reserved 64 bytes. So that
btrfs_root_item remains same.
Signed-off-by: Anand Jain <anand.j...@oracle.com>
---
fs/btrfs/ctree.h | 12 +++++++++++-
fs/btrfs/ioctl.c | 32 ++++++++++++++++++++++++++++++++
fs/btrfs/ioctl.h | 2 ++
fs/btrfs/transaction.c | 1 +
4 files changed, 46 insertions(+), 1 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 994d255..039e11c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -383,6 +383,7 @@ struct btrfs_header {
*/
#define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
#define BTRFS_LABEL_SIZE 256
+#define BTRFS_SUBVOL_LABEL_SIZE 32
/*
* just in case we somehow lose the roots and are not able to mount,
@@ -759,7 +760,8 @@ struct btrfs_root_item {
struct btrfs_timespec otime;
struct btrfs_timespec stime;
struct btrfs_timespec rtime;
- __le64 reserved[8]; /* for future */
+ char label[BTRFS_SUBVOL_LABEL_SIZE];
+ __le64 reserved[4]; /* for future */
} __attribute__ ((__packed__));
/*
@@ -2441,6 +2443,14 @@ static inline bool btrfs_root_readonly(struct btrfs_root
*root)
{
return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY))
!= 0;
}
+static inline char * btrfs_root_label(struct btrfs_root_item *root_item)
+{
+ return (root_item->label);
+}
+static inline void btrfs_root_set_label(struct btrfs_root_item *root_item,
char *val)
+{
+ memcpy(root_item->label, val, BTRFS_SUBVOL_LABEL_SIZE);
+}
/* struct btrfs_root_backup */
BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index e58bd9d..aa4eb23 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3725,6 +3725,34 @@ static int btrfs_ioctl_set_label(struct btrfs_root
*root, void __user *arg)
return 0;
}
+static int btrfs_ioctl_subvol_getlabel(struct btrfs_root *root,
+ void __user *arg)
+{
+ char *label;
+
+ label = btrfs_root_label(&root->root_item);
+ if (copy_to_user(arg, label, BTRFS_SUBVOL_LABEL_SIZE))
+ return -EFAULT;
+ return 0;
+}
+
+static int btrfs_ioctl_subvol_setlabel(struct btrfs_root *root,
+ void __user *arg)
+{
+ char label[BTRFS_SUBVOL_LABEL_SIZE+1];
+ struct btrfs_trans_handle *trans;
+
+ if (copy_from_user(label, arg, BTRFS_SUBVOL_LABEL_SIZE))
+ return -EFAULT;
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+ btrfs_root_set_label(&root->root_item, label);
+ btrfs_end_transaction(trans, root);
+
+ return 0;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -3827,6 +3855,10 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_get_label(root, argp);
case BTRFS_IOC_SET_LABEL:
return btrfs_ioctl_set_label(root, argp);
+ case BTRFS_IOC_SUBVOL_GETLABEL:
+ return btrfs_ioctl_subvol_getlabel(root, argp);
+ case BTRFS_IOC_SUBVOL_SETLABEL:
+ return btrfs_ioctl_subvol_setlabel(root, argp);
}
return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 0c60fcb..1009a0c 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -455,4 +455,6 @@ struct btrfs_ioctl_send_args {
struct btrfs_ioctl_get_dev_stats)
#define BTRFS_IOC_GET_LABEL _IOR(BTRFS_IOCTL_MAGIC, 53, __u64)
#define BTRFS_IOC_SET_LABEL _IOW(BTRFS_IOCTL_MAGIC, 54, __u64)
+#define BTRFS_IOC_SUBVOL_GETLABEL _IOWR(BTRFS_IOCTL_MAGIC, 55, __u64)
+#define BTRFS_IOC_SUBVOL_SETLABEL _IOW(BTRFS_IOCTL_MAGIC, 56, __u64)
#endif
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 04bbfb1..0a3f8b3 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1118,6 +1118,7 @@ static noinline int create_pending_snapshot(struct
btrfs_trans_handle *trans,
memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
btrfs_set_root_stransid(new_root_item, 0);
btrfs_set_root_rtransid(new_root_item, 0);
+ memset(&new_root_item->label, 0, BTRFS_SUBVOL_LABEL_SIZE);
old = btrfs_lock_root_node(root);
ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
--
1.7.1
--
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