@@ -577,6 +577,7 @@ __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp,
ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
u64 dst_pos, u64 count)
{
+ ssize_t ret;
/*
* Limit copy to 4MB to prevent indefinitely blocking an nfsd
@@ -587,7 +588,12 @@ ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
* limit like this and pipeline multiple COPY requests.
*/
count = min_t(u64, count, 1 << 22);
- return vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
+ ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
+
+ if (ret == -EOPNOTSUPP || ret == -EXDEV)
+ ret = generic_copy_file_range(src, src_pos, dst, dst_pos,
+ count, 0);
+ return ret;
}
__be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
@@ -1381,28 +1381,6 @@ ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
}
EXPORT_SYMBOL(generic_copy_file_range);
-static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- size_t len, unsigned int flags)
-{
- /*
- * Although we now allow filesystems to handle cross sb copy, passing
- * a file of the wrong filesystem type to filesystem driver can result
- * in an attempt to dereference the wrong type of ->private_data, so
- * avoid doing that until we really have a good reason. NFS defines
- * several different file_system_type structures, but they all end up
- * using the same ->copy_file_range() function pointer.
- */
- if (file_out->f_op->copy_file_range &&
- file_out->f_op->copy_file_range == file_in->f_op->copy_file_range)
- return file_out->f_op->copy_file_range(file_in, pos_in,
- file_out, pos_out,
- len, flags);
-
- return generic_copy_file_range(file_in, pos_in, file_out, pos_out, len,
- flags);
-}
-
/*
* Performs necessary checks before doing a file copy
*
@@ -1424,6 +1402,25 @@ static int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
if (ret)
return ret;
+ /*
+ * Although we now allow filesystems to handle cross sb copy, passing
+ * a file of the wrong filesystem type to filesystem driver can result
+ * in an attempt to dereference the wrong type of ->private_data, so
+ * avoid doing that until we really have a good reason. NFS defines
+ * several different file_system_type structures, but they all end up
+ * using the same ->copy_file_range() function pointer.
+ */
+ if (file_out->f_op->copy_file_range) {
+ if (file_in->f_op->copy_file_range !=
+ file_out->f_op->copy_file_range)
+ return -EXDEV;
+ } else if (file_in->f_op->remap_file_range) {
+ if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
+ return -EXDEV;
+ } else {
+ return -EOPNOTSUPP;
+ }
+
/* Don't touch certain kinds of inodes */
if (IS_IMMUTABLE(inode_out))
return -EPERM;
@@ -1489,26 +1486,36 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
file_start_write(file_out);
/*
- * Try cloning first, this is supported by more file systems, and
- * more efficient if both clone and copy are supported (e.g. NFS).
+ * Cloning is supported by more file systems, so we implement copy on
+ * same sb using clone, but for filesystems were both clone and copy
+ * are supported (e.g. NFS), we only call the copy method.
*/
- if (file_in->f_op->remap_file_range &&
- file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) {
- loff_t cloned;
-
- cloned = file_in->f_op->remap_file_range(file_in, pos_in,
+ if (file_out->f_op->copy_file_range) {
+ ret = file_out->f_op->copy_file_range(file_in, pos_in,
+ file_out, pos_out,
+ len, flags);
+ } else if (file_in->f_op->remap_file_range &&
+ file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) {
+ ret = file_in->f_op->remap_file_range(file_in, pos_in,
file_out, pos_out,
min_t(loff_t, MAX_RW_COUNT, len),
REMAP_FILE_CAN_SHORTEN);
- if (cloned > 0) {
- ret = cloned;
- goto done;
- }
}
- ret = do_copy_file_range(file_in, pos_in, file_out, pos_out, len,
- flags);
- WARN_ON_ONCE(ret == -EOPNOTSUPP);
+ if (ret > 0)
+ goto done;
+
+ /*
+ * We can get here if filesystem supports clone but rejected the clone
+ * request (e.g. because it was not block aligned).
+ * In that case, fall back to kernel copy so we are able to maintain a
+ * consistent story about which filesystems support copy_file_range()
+ * and which filesystems do not, that will allow userspace tools to
+ * make consistent desicions w.r.t using copy_file_range().
+ */
+ ret = generic_copy_file_range(file_in, pos_in, file_out, pos_out, len,
+ flags);
+
done:
if (ret > 0) {
fsnotify_access(file_in);