[RESEND PATCH V4 1/2] Btrfs: Add a new ioctl to get the label of a mounted filesystem
From: Jeff Liu <hidden>
Date: 2012-12-12 03:23:17
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
Signed-off-by: Jie Liu <redacted> Signed-off-by: Anand Jain <redacted> --- fs/btrfs/ioctl.c | 14 ++++++++++++++ fs/btrfs/ioctl.h | 2 ++ 2 files changed, 16 insertions(+)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 8fcf9a5..b0a5e17 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c@@ -3699,6 +3699,18 @@ out: return ret; } +static int btrfs_ioctl_get_fslabel(struct btrfs_root *root, void __user *arg) +{ + const char *label = root->fs_info->super_copy->label; + int ret; + + mutex_lock(&root->fs_info->volume_mutex); + ret = copy_to_user(arg, label, strlen(label)); + mutex_unlock(&root->fs_info->volume_mutex); + + return ret ? -EFAULT : 0; +} + long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) {
@@ -3797,6 +3809,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_qgroup_create(root, argp); case BTRFS_IOC_QGROUP_LIMIT: return btrfs_ioctl_qgroup_limit(root, argp); + case BTRFS_IOC_GET_FSLABEL: + return btrfs_ioctl_get_fslabel(root, argp); } return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 731e287..98f896f 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h@@ -453,4 +453,6 @@ struct btrfs_ioctl_send_args { struct btrfs_ioctl_qgroup_limit_args) #define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \ struct btrfs_ioctl_get_dev_stats) +#define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 53, \ + char[BTRFS_LABEL_SIZE]) #endif
--
1.7.9.5