nfsd: Ensure exclusion between CLONE and WRITE errors

Ensure that we can distinguish between synchronous CLONE and
WRITE errors, and that we can assign them correctly.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 7950f2e..126149b 100644 (file)
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -536,22 +536,33 @@ __be32 nfsd4_clone_file_range(struct nfsd_file *nf_src, u64 src_pos,
        struct file *src = nf_src->nf_file;
        struct file *dst = nf_dst->nf_file;
        loff_t cloned;
+       __be32 ret = 0;
 
+       down_write(&nf_dst->nf_rwsem);
        cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
-       if (cloned < 0)
-               return nfserrno(cloned);
-       if (count && cloned != count)
-               return nfserrno(-EINVAL);
+       if (cloned < 0) {
+               ret = nfserrno(cloned);
+               goto out_err;
+       }
+       if (count && cloned != count) {
+               ret = nfserrno(-EINVAL);
+               goto out_err;
+       }
        if (sync) {
                loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
                int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
 
                if (!status)
                        status = commit_inode_metadata(file_inode(src));
-               if (status < 0)
-                       return nfserrno(status);
+               if (status < 0) {
+                       nfsd_reset_boot_verifier(net_generic(nf_dst->nf_net,
+                                                nfsd_net_id));
+                       ret = nfserrno(status);
+               }
        }
-       return 0;
+out_err:
+       up_write(&nf_dst->nf_rwsem);
+       return ret;
 }
 
 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,