This is the second patch, the one kernel related. This patch introduces two new
ioctls to read and change the label of a btrfs filesystem.
This patch is a repost of a previous patch of Morey Roof.
If request I can modify the patch. Comments are welcome.
BR
G.Baroncelli
---
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 645a179..18f3ada 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1301,6 +1301,53 @@ long btrfs_ioctl_trans_end(struct file *file)
return 0;
}
+long btrfs_ioctl_set_label(struct btrfs_root *root, void __user *arg)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_ioctl_label_args *label_args;
+ int ret = 0;
+
+ label_args = kmalloc(sizeof(*label_args), GFP_NOFS);
+
+ if (!label_args)
+ return -ENOMEM;
+
+ if (copy_from_user(label_args, arg, sizeof(*label_args)))
+ {
+ ret = -EFAULT;
+ } else
+ {
+ /* Everything looks good, so lets do a label change */
+ label_args->name[BTRFS_LABEL_SIZE] = 0x00;
+ trans = btrfs_start_transaction(root, 1);
+ strncpy(root->fs_info->super_copy.label, label_args->name,
BTRFS_LABEL_SIZE);
+ btrfs_commit_transaction(trans, root);
+ }
+
+ kfree(label_args);
+ return ret;
+}
+
+long btrfs_ioctl_get_label(struct btrfs_root *root, void __user *arg)
+{
+ struct btrfs_ioctl_label_args *label_args;
+ int ret = 0;
+
+ label_args = kmalloc(sizeof(*label_args), GFP_NOFS);
+
+ if (!label_args)
+ return -ENOMEM;
+
+ strncpy(label_args->name, root->fs_info->super_copy.label,
BTRFS_LABEL_SIZE);
+ if (copy_to_user(arg, label_args, sizeof(*label_args)))
+ {
+ ret = -EFAULT;
+ }
+
+ kfree(label_args);
+ return ret;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -1338,6 +1385,10 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_trans_start(file);
case BTRFS_IOC_TRANS_END:
return btrfs_ioctl_trans_end(file);
+ case BTRFS_IOC_SET_LABEL:
+ return btrfs_ioctl_set_label(root, (void __user *)arg);
+ case BTRFS_IOC_GET_LABEL:
+ return btrfs_ioctl_get_label(root, (void __user *)arg);
case BTRFS_IOC_SYNC:
btrfs_sync_fs(file->f_dentry->d_sb, 1);
return 0;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index bc49914..995756d 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -19,6 +19,7 @@
#ifndef __IOCTL_
#define __IOCTL_
#include <linux/ioctl.h>
+#include "ctree.h"
#define BTRFS_IOCTL_MAGIC 0x94
#define BTRFS_VOL_NAME_MAX 255
@@ -30,6 +31,10 @@ struct btrfs_ioctl_vol_args {
char name[BTRFS_PATH_NAME_MAX + 1];
};
+struct btrfs_ioctl_label_args {
+ char name[BTRFS_LABEL_SIZE + 1];
+};
+
struct btrfs_ioctl_clone_range_args {
__s64 src_fd;
__u64 src_offset, src_length;
@@ -67,4 +72,11 @@ struct btrfs_ioctl_clone_range_args {
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \
struct btrfs_ioctl_vol_args)
+
+/* Used to set and get the current volume label */
+#define BTRFS_IOC_SET_LABEL _IOW(BTRFS_IOCTL_MAGIC, 16, \
+ struct btrfs_ioctl_label_args)
+#define BTRFS_IOC_GET_LABEL _IOW(BTRFS_IOCTL_MAGIC, 17, \
+ struct btrfs_ioctl_label_args)
+
#endif
---
--
gpg key@ keyserver.linux.it: Goffredo Baroncelli (ghigo)
<kreijackATinwind.it>
Key fingerprint = 4769 7E51 5293 D36C 814E C054 BF04 F161 3DC5 0512