Add a new ioctl to retrieve the UUID of a mounted xfs filesystem. This is a
precursor to adding the SETFSUUID ioctl.
Signed-off-by: Catherine Hoang <catherine.hoang@xxxxxxxxxx>
Reviewed-by: Allison Henderson <allison.henderson@xxxxxxxxxx>
---
fs/xfs/xfs_ioctl.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 1f783e979629..cf77715afe9e 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1865,6 +1865,39 @@ xfs_fs_eofblocks_from_user(
return 0;
}
+static int
+xfs_ioctl_getuuid(
+ struct xfs_mount *mp,
+ struct fsuuid __user *ufsuuid)
+{
+ struct fsuuid fsuuid;
+ __u8 uuid[UUID_SIZE];
+
+ if (copy_from_user(&fsuuid, ufsuuid, sizeof(fsuuid)))
+ return -EFAULT;
+
+ if (fsuuid.fsu_len == 0) {
+ fsuuid.fsu_len = UUID_SIZE;
+ if (copy_to_user(&ufsuuid->fsu_len, &fsuuid.fsu_len,
+ sizeof(fsuuid.fsu_len)))
+ return -EFAULT;
+ return 0;
+ }
+
+ if (fsuuid.fsu_len < UUID_SIZE || fsuuid.fsu_flags != 0)
+ return -EINVAL;
+
+ spin_lock(&mp->m_sb_lock);
+ memcpy(uuid, &mp->m_sb.sb_uuid, UUID_SIZE);
+ spin_unlock(&mp->m_sb_lock);
+
+ fsuuid.fsu_len = UUID_SIZE;
+ if (copy_to_user(ufsuuid, &fsuuid, sizeof(fsuuid)) ||
+ copy_to_user(&ufsuuid->fsu_uuid[0], uuid, UUID_SIZE))
+ return -EFAULT;
+ return 0;
+}
+
/*
* These long-unused ioctls were removed from the official ioctl API in 5.17,
* but retain these definitions so that we can log warnings about them.
@@ -2153,6 +2186,9 @@ xfs_file_ioctl(
return error;
}
+ case FS_IOC_GETFSUUID:
+ return xfs_ioctl_getuuid(mp, arg);
+
default:
return -ENOTTY;
}
--
2.25.1
