Linux 5.6 compat: struct proc_ops

The proc_ops structure was introduced to replace the use of of the
file_operations structure when registering proc handlers.  This
change creates a new kstat_proc_op_t typedef for compatibility
which can be used to pass around the correct structure.

This change additionally adds the 'const' keyword to all of the
existing proc operations structures.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #9961

module/os/linux/spl/spl-kstat.c

@@ -507,12 +507,20 @@ proc_kstat_write(struct file *filp, const char __user *buf, size_t len,
 	return (len);
 }
 
-static struct file_operations proc_kstat_operations = {
+static const kstat_proc_op_t proc_kstat_operations = {
+#ifdef HAVE_PROC_OPS_STRUCT
+	.proc_open	= proc_kstat_open,
+	.proc_write	= proc_kstat_write,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release,
+#else
 	.open		= proc_kstat_open,
 	.write		= proc_kstat_write,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
+#endif
 };
 
 void
@@ -656,7 +664,7 @@ kstat_detect_collision(kstat_proc_entry_t *kpep)
  */
 void
 kstat_proc_entry_install(kstat_proc_entry_t *kpep, mode_t mode,
-    const struct file_operations *file_ops, void *data)
+    const kstat_proc_op_t *proc_ops, void *data)
 {
 	kstat_module_t *module;
 	kstat_proc_entry_t *tmp = NULL;
@@ -690,7 +698,7 @@ kstat_proc_entry_install(kstat_proc_entry_t *kpep, mode_t mode,
 
 	kpep->kpe_owner = module;
 	kpep->kpe_proc = proc_create_data(kpep->kpe_name, mode,
-	    module->ksm_proc, file_ops, data);
+	    module->ksm_proc, proc_ops, data);
 	if (kpep->kpe_proc == NULL) {
 		list_del_init(&kpep->kpe_list);
 		if (list_empty(&module->ksm_kstat_list))

module/os/linux/spl/spl-proc.c

@@ -532,11 +532,18 @@ proc_slab_open(struct inode *inode, struct file *filp)
 	return (seq_open(filp, &slab_seq_ops));
 }
 
-static struct file_operations proc_slab_operations = {
-	.open	   = proc_slab_open,
-	.read	   = seq_read,
-	.llseek	 = seq_lseek,
+static const kstat_proc_op_t proc_slab_operations = {
+#ifdef HAVE_PROC_OPS_STRUCT
+	.proc_open	= proc_slab_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release,
+#else
+	.open		= proc_slab_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
 	.release	= seq_release,
+#endif
 };
 
 static void
@@ -571,18 +578,32 @@ proc_taskq_open(struct inode *inode, struct file *filp)
 	return (seq_open(filp, &taskq_seq_ops));
 }
 
-static struct file_operations proc_taskq_all_operations = {
+static const kstat_proc_op_t proc_taskq_all_operations = {
+#ifdef HAVE_PROC_OPS_STRUCT
+	.proc_open	= proc_taskq_all_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release,
+#else
 	.open		= proc_taskq_all_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
+#endif
 };
 
-static struct file_operations proc_taskq_operations = {
+static const kstat_proc_op_t proc_taskq_operations = {
+#ifdef HAVE_PROC_OPS_STRUCT
+	.proc_open	= proc_taskq_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release,
+#else
 	.open		= proc_taskq_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
+#endif
 };
 
 static struct ctl_table spl_kmem_table[] = {

module/os/linux/spl/spl-procfs-list.c

@@ -185,13 +185,20 @@ procfs_list_write(struct file *filp, const char __user *buf, size_t len,
 	return (len);
 }
 
-static struct file_operations procfs_list_operations = {
-	.owner		= THIS_MODULE,
+static const kstat_proc_op_t procfs_list_operations = {
+#ifdef HAVE_PROC_OPS_STRUCT
+	.proc_open	= procfs_list_open,
+	.proc_write	= procfs_list_write,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release_private,
+#else
 	.open		= procfs_list_open,
 	.write		= procfs_list_write,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= seq_release_private,
+#endif
 };
 
 /*