efs: fix the efs new mount api implementation

Commit 39a6c66 (efs: convert efs to use the new mount api)
did not include anything from v2 and v3 that were also submitted.
Fix this by bringing in those changes that were proposed in v2 and
v3.

Fixes: 39a6c66 efs: convert efs to use the new mount api.

Signed-off-by: Bill O'Donnell <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

Author: Bill O'Donnell

fs/efs/super.c

@@ -15,7 +15,6 @@
 #include <linux/vfs.h>
 #include <linux/blkdev.h>
 #include <linux/fs_context.h>
-#include <linux/fs_parser.h>
 #include "efs.h"
 #include <linux/efs_vh.h>
 #include <linux/efs_fs_sb.h>
@@ -49,15 +48,6 @@ static struct pt_types sgi_pt_types[] = {
 	{0,		NULL}
 };
 
-enum {
-	Opt_explicit_open,
-};
-
-static const struct fs_parameter_spec efs_param_spec[] = {
-	fsparam_flag    ("explicit-open",       Opt_explicit_open),
-	{}
-};
-
 /*
  * File system definition and registration.
  */
@@ -67,7 +57,6 @@ static struct file_system_type efs_fs_type = {
 	.kill_sb		= efs_kill_sb,
 	.fs_flags		= FS_REQUIRES_DEV,
 	.init_fs_context	= efs_init_fs_context,
-	.parameters		= efs_param_spec,
 };
 MODULE_ALIAS_FS("efs");
 
@@ -265,7 +254,8 @@ static int efs_fill_super(struct super_block *s, struct fs_context *fc)
 	if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {
 		pr_err("device does not support %d byte blocks\n",
 			EFS_BLOCKSIZE);
-		return -EINVAL;
+		return invalf(fc, "device does not support %d byte blocks\n",
+			      EFS_BLOCKSIZE);
 	}
 
 	/* read the vh (volume header) block */
@@ -327,56 +317,29 @@ static int efs_fill_super(struct super_block *s, struct fs_context *fc)
 	return 0;
 }
 
-static void efs_free_fc(struct fs_context *fc)
-{
-	kfree(fc->fs_private);
-}
-
 static int efs_get_tree(struct fs_context *fc)
 {
 	return get_tree_bdev(fc, efs_fill_super);
 }
 
-static int efs_parse_param(struct fs_context *fc, struct fs_parameter *param)
-{
-	int token;
-	struct fs_parse_result result;
-
-	token = fs_parse(fc, efs_param_spec, param, &result);
-	if (token < 0)
-		return token;
-	return 0;
-}
-
 static int efs_reconfigure(struct fs_context *fc)
 {
 	sync_filesystem(fc->root->d_sb);
+	fc->sb_flags |= SB_RDONLY;
 
 	return 0;
 }
 
-struct efs_context {
-	unsigned long s_mount_opts;
-};
-
 static const struct fs_context_operations efs_context_opts = {
-	.parse_param	= efs_parse_param,
 	.get_tree	= efs_get_tree,
 	.reconfigure	= efs_reconfigure,
-	.free		= efs_free_fc,
 };
 
 /*
  * Set up the filesystem mount context.
  */
 static int efs_init_fs_context(struct fs_context *fc)
 {
-	struct efs_context *ctx;
-
-	ctx = kzalloc(sizeof(struct efs_context), GFP_KERNEL);
-	if (!ctx)
-		return -ENOMEM;
-	fc->fs_private = ctx;
 	fc->ops = &efs_context_opts;
 
 	return 0;