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| author | jeff.liu <jeff.liu@oracle.com> | 2013-01-05 02:48:01 +0000 |
|---|---|---|
| committer | Josef Bacik <jbacik@fusionio.com> | 2013-02-20 12:59:58 -0500 |
| commit | 867ab667e74377160c4a683375ee5b8bf8801724 (patch) | |
| tree | 9473c309f58be6efd176f09417358ea42a4f8db4 /fs | |
| parent | 569e0f358c0c37f6733702d4a5d2c412860f7169 (diff) | |
| download | linux-867ab667e74377160c4a683375ee5b8bf8801724.tar.gz linux-867ab667e74377160c4a683375ee5b8bf8801724.tar.bz2 linux-867ab667e74377160c4a683375ee5b8bf8801724.zip | |
Btrfs: Add a new ioctl to get the label of a mounted file system
Add a new ioctl(2) BTRFS_IOC_GET_FSLABLE, so that we can get the label upon a mounted filesystem.
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>
Cc: Goffredo Baroncelli <kreijack@inwind.it>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/ioctl.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index d02ec577f70f..fcc15a6804a9 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3917,6 +3917,25 @@ 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; + size_t len = strnlen(label, BTRFS_LABEL_SIZE); + int ret; + + if (len == BTRFS_LABEL_SIZE) { + pr_warn("btrfs: label is too long, return the first %zu bytes\n", + --len); + } + + mutex_lock(&root->fs_info->volume_mutex); + ret = copy_to_user(arg, label, len); + mutex_unlock(&root->fs_info->volume_mutex); + + return ret ? -EFAULT : 0; +} + long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -4017,6 +4036,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_qgroup_limit(file, argp); case BTRFS_IOC_DEV_REPLACE: return btrfs_ioctl_dev_replace(root, argp); + case BTRFS_IOC_GET_FSLABEL: + return btrfs_ioctl_get_fslabel(file, argp); } return -ENOTTY; |