linux: implement filesystem-side copy/clone functions for EL7

Redhat have backported copy_file_range and clone_file_range to the EL7
kernel using an "extended file operations" wrapper structure. This
connects all that up to let cloning work there too.

Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Kay Pedersen <[email protected]>
Signed-off-by: Rob Norris <[email protected]>
Sponsored-By: OpenDrives Inc.
Sponsored-By: Klara Inc.
Closes #15050

4 files changed, 34 insertions, 8 deletions

diff --git a/module/os/linux/zfs/zfs_vfsops.c b/module/os/linux/zfs/zfs_vfsops.c
index 87c4e6dca..464c12e11 100644
--- a/module/os/linux/zfs/zfs_vfsops.c
+++ b/module/os/linux/zfs/zfs_vfsops.c
@@ -2092,6 +2092,9 @@ zfs_init(void)
 	zfs_znode_init();
 	dmu_objset_register_type(DMU_OST_ZFS, zpl_get_file_info);
 	register_filesystem(&zpl_fs_type);
+#ifdef HAVE_VFS_FILE_OPERATIONS_EXTEND
+	register_fo_extend(&zpl_file_operations);
+#endif
 }
 
 void
@@ -2102,6 +2105,9 @@ zfs_fini(void)
 	 */
 	taskq_wait(system_delay_taskq);
 	taskq_wait(system_taskq);
+#ifdef HAVE_VFS_FILE_OPERATIONS_EXTEND
+	unregister_fo_extend(&zpl_file_operations);
+#endif
 	unregister_filesystem(&zpl_fs_type);
 	zfs_znode_fini();
 	zfsctl_fini();
diff --git a/module/os/linux/zfs/zfs_znode.c b/module/os/linux/zfs/zfs_znode.c
index 02b1af3ed..335ae3460 100644
--- a/module/os/linux/zfs/zfs_znode.c
+++ b/module/os/linux/zfs/zfs_znode.c
@@ -415,7 +415,11 @@ zfs_inode_set_ops(zfsvfs_t *zfsvfs, struct inode *ip)
 	switch (ip->i_mode & S_IFMT) {
 	case S_IFREG:
 		ip->i_op = &zpl_inode_operations;
+#ifdef HAVE_VFS_FILE_OPERATIONS_EXTEND
+		ip->i_fop = &zpl_file_operations.kabi_fops;
+#else
 		ip->i_fop = &zpl_file_operations;
+#endif
 		ip->i_mapping->a_ops = &zpl_address_space_operations;
 		break;
 
@@ -455,7 +459,11 @@ zfs_inode_set_ops(zfsvfs_t *zfsvfs, struct inode *ip)
 		/* Assume the inode is a file and attempt to continue */
 		ip->i_mode = S_IFREG | 0644;
 		ip->i_op = &zpl_inode_operations;
+#ifdef HAVE_VFS_FILE_OPERATIONS_EXTEND
+		ip->i_fop = &zpl_file_operations.kabi_fops;
+#else
 		ip->i_fop = &zpl_file_operations;
+#endif
 		ip->i_mapping->a_ops = &zpl_address_space_operations;
 		break;
 	}
diff --git a/module/os/linux/zfs/zpl_file.c b/module/os/linux/zfs/zpl_file.c
index 87a248af8..73526db73 100644
--- a/module/os/linux/zfs/zpl_file.c
+++ b/module/os/linux/zfs/zpl_file.c
@@ -1311,7 +1311,12 @@ const struct address_space_operations zpl_address_space_operations = {
 #endif
 };
 
+#ifdef HAVE_VFS_FILE_OPERATIONS_EXTEND
+const struct file_operations_extend zpl_file_operations = {
+	.kabi_fops = {
+#else
 const struct file_operations zpl_file_operations = {
+#endif
 	.open		= zpl_open,
 	.release	= zpl_release,
 	.llseek		= zpl_llseek,
@@ -1341,12 +1346,12 @@ const struct file_operations zpl_file_operations = {
 #ifdef HAVE_VFS_COPY_FILE_RANGE
 	.copy_file_range	= zpl_copy_file_range,
 #endif
-#ifdef HAVE_VFS_REMAP_FILE_RANGE
-	.remap_file_range	= zpl_remap_file_range,
-#endif
 #ifdef HAVE_VFS_CLONE_FILE_RANGE
 	.clone_file_range	= zpl_clone_file_range,
 #endif
+#ifdef HAVE_VFS_REMAP_FILE_RANGE
+	.remap_file_range	= zpl_remap_file_range,
+#endif
 #ifdef HAVE_VFS_DEDUPE_FILE_RANGE
 	.dedupe_file_range	= zpl_dedupe_file_range,
 #endif
@@ -1357,6 +1362,11 @@ const struct file_operations zpl_file_operations = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= zpl_compat_ioctl,
 #endif
+#ifdef HAVE_VFS_FILE_OPERATIONS_EXTEND
+	}, /* kabi_fops */
+	.copy_file_range	= zpl_copy_file_range,
+	.clone_file_range	= zpl_clone_file_range,
+#endif
 };
 
 const struct file_operations zpl_dir_file_operations = {
diff --git a/module/os/linux/zfs/zpl_file_range.c b/module/os/linux/zfs/zpl_file_range.c
index aad502a80..18efebfc1 100644
--- a/module/os/linux/zfs/zpl_file_range.c
+++ b/module/os/linux/zfs/zpl_file_range.c
@@ -77,7 +77,8 @@ __zpl_clone_file_range(struct file *src_file, loff_t src_off,
 	return ((ssize_t)len_o);
 }
 
-#ifdef HAVE_VFS_COPY_FILE_RANGE
+#if defined(HAVE_VFS_COPY_FILE_RANGE) || \
+    defined(HAVE_VFS_FILE_OPERATIONS_EXTEND)
 /*
  * Entry point for copy_file_range(). Copy len bytes from src_off in src_file
  * to dst_off in dst_file. We are permitted to do this however we like, so we
@@ -94,7 +95,7 @@ zpl_copy_file_range(struct file *src_file, loff_t src_off,
 		return (-EINVAL);
 
 	/* Try to do it via zfs_clone_range() */
-	ret =__zpl_clone_file_range(src_file, src_off,
+	ret = __zpl_clone_file_range(src_file, src_off,
 	    dst_file, dst_off, len);
 
 #ifdef HAVE_VFS_GENERIC_COPY_FILE_RANGE
@@ -109,7 +110,7 @@ zpl_copy_file_range(struct file *src_file, loff_t src_off,
 
 	return (ret);
 }
-#endif /* HAVE_VFS_COPY_FILE_RANGE */
+#endif /* HAVE_VFS_COPY_FILE_RANGE || HAVE_VFS_FILE_OPERATIONS_EXTEND */
 
 #ifdef HAVE_VFS_REMAP_FILE_RANGE
 /*
@@ -152,7 +153,8 @@ zpl_remap_file_range(struct file *src_file, loff_t src_off,
 }
 #endif /* HAVE_VFS_REMAP_FILE_RANGE */
 
-#ifdef HAVE_VFS_CLONE_FILE_RANGE
+#if defined(HAVE_VFS_CLONE_FILE_RANGE) || \
+    defined(HAVE_VFS_FILE_OPERATIONS_EXTEND)
 /*
  * Entry point for FICLONE and FICLONERANGE, before Linux 4.20.
  */
@@ -167,7 +169,7 @@ zpl_clone_file_range(struct file *src_file, loff_t src_off,
 	return (__zpl_clone_file_range(src_file, src_off,
 	    dst_file, dst_off, len));
 }
-#endif /* HAVE_VFS_CLONE_FILE_RANGE */
+#endif /* HAVE_VFS_CLONE_FILE_RANGE || HAVE_VFS_FILE_OPERATIONS_EXTEND */
 
 #ifdef HAVE_VFS_DEDUPE_FILE_RANGE
 /*