Jeff Liu
2012-Dec-17 11:22 UTC
[RFC PATCH V5 1/2] Btrfs: Add a new ioctl to get the label of a mounted filesystem
Introduce a new ioctl BTRFS_IOC_GET_FSLABEL to fetch the label of a mounted file
system.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
---
fs/btrfs/ioctl.c | 15 +++++++++++++++
fs/btrfs/ioctl.h | 2 ++
2 files changed, 17 insertions(+)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 8fcf9a5..6a2488a 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3699,6 +3699,19 @@ out:
return ret;
}
+static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
+{
+ struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
+ 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 +3810,8 @@ 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(file, argp);
}
return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 731e287..5b2cbef 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -451,6 +451,8 @@ struct btrfs_ioctl_send_args {
struct btrfs_ioctl_qgroup_create_args)
#define BTRFS_IOC_QGROUP_LIMIT _IOR(BTRFS_IOCTL_MAGIC, 43, \
struct btrfs_ioctl_qgroup_limit_args)
+#define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 49, \
+ char[BTRFS_LABEL_SIZE])
#define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \
struct btrfs_ioctl_get_dev_stats)
#endif
--
1.7.9.5
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Miao Xie
2012-Dec-17 11:59 UTC
Re: [RFC PATCH V5 1/2] Btrfs: Add a new ioctl to get the label of a mounted filesystem
On mon, 17 Dec 2012 19:22:02 +0800, Jeff Liu wrote:> Introduce a new ioctl BTRFS_IOC_GET_FSLABEL to fetch the label of a mounted file system. > > Signed-off-by: Jie Liu <jeff.liu@oracle.com> > Signed-off-by: Anand Jain <anand.jain@oracle.com> > Cc: Miao Xie <miaox@cn.fujitsu.com>Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>> > --- > fs/btrfs/ioctl.c | 15 +++++++++++++++ > fs/btrfs/ioctl.h | 2 ++ > 2 files changed, 17 insertions(+) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 8fcf9a5..6a2488a 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -3699,6 +3699,19 @@ out: > return ret; > } > > +static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg) > +{ > + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; > + 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 +3810,8 @@ 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(file, argp); > } > > return -ENOTTY; > diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h > index 731e287..5b2cbef 100644 > --- a/fs/btrfs/ioctl.h > +++ b/fs/btrfs/ioctl.h > @@ -451,6 +451,8 @@ struct btrfs_ioctl_send_args { > struct btrfs_ioctl_qgroup_create_args) > #define BTRFS_IOC_QGROUP_LIMIT _IOR(BTRFS_IOCTL_MAGIC, 43, \ > struct btrfs_ioctl_qgroup_limit_args) > +#define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 49, \ > + char[BTRFS_LABEL_SIZE]) > #define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \ > struct btrfs_ioctl_get_dev_stats) > #endif >-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html