nfs42: respect clone_blksize

draft-ietf-nfsv4-minorversion2-38.txt says:
   Both cl_src_offset and
   cl_dst_offset must be aligned to the clone block size Section 12.2.1.
   The number of bytes to be cloned must be a multiple of the clone
   block size, except in the case in which cl_src_offset plus the number
   of bytes to be cloned is equal to the source file size.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index fc68ba5f030cfea044e609df8da768b9e6f992cb..4f463dd8bae3c2aa979cd523f7401a49edac17b7 100644 (file)
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -199,8 +199,10 @@ nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
                  u64 src_off, u64 dst_off, u64 count)
 {
        struct inode *dst_inode = file_inode(dst_file);
+       struct nfs_server *server = NFS_SERVER(dst_inode);
        struct fd src_file;
        struct inode *src_inode;
+       unsigned int bs = server->clone_blksize;
        int ret;
 
        /* dst file must be opened for writing */
@@ -238,6 +240,15 @@ nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
            src_inode->i_sb != dst_inode->i_sb)
                goto out_fput;
 
+       /* check alignment w.r.t. clone_blksize */
+       ret = -EINVAL;
+       if (bs) {
+               if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
+                       goto out_fput;
+               if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
+                       goto out_fput;
+       }
+
        /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
        if (dst_inode < src_inode) {
                mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_PARENT);