ext4: fix incorrect options show of original mount_opt and extend mount_opt2

maillist inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6D5XF

Reference: https://lore.kernel.org/linux-ext4/20230130111138.76tp6pij3yhh4brh@quack3/T/#t

--------------------------------

Current _ext4_show_options() do not distinguish MOPT_2 flag, so it mixed
extend sbi->s_mount_opt2 options with sbi->s_mount_opt, it could lead to
show incorrect options, e.g. show fc_debug_force if we mount with
errors=continue mode and miss it if we set.

  $ mkfs.ext4 /dev/pmem0
  $ mount -o errors=remount-ro /dev/pmem0 /mnt
  $ cat /proc/fs/ext4/pmem0/options | grep fc_debug_force
    #empty
  $ mount -o remount,errors=continue /mnt
  $ cat /proc/fs/ext4/pmem0/options | grep fc_debug_force
    fc_debug_force
  $ mount -o remount,errors=remount-ro,fc_debug_force /mnt
  $ cat /proc/fs/ext4/pmem0/options | grep fc_debug_force
    #empty

Fixes: 995a3ed6 ("ext4: add fast_commit feature and handling for extended mount options")
Signed-off-by: NZhang Yi <yi.zhang@huawei.com>

Conflict:
  fs/ext4/super.c
Reviewed-by: NZhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: NZhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

fs/ext4/ext4.h

@@ -1459,6 +1459,7 @@ struct ext4_sb_info {
 	unsigned int s_mount_opt2;
 	unsigned long s_mount_flags;
 	unsigned int s_def_mount_opt;
+	unsigned int s_def_mount_opt2;
 	ext4_fsblk_t s_sb_block;
 	atomic64_t s_resv_clusters;
 	kuid_t s_resuid;

fs/ext4/super.c

@@ -2585,7 +2585,7 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_super_block *es = sbi->s_es;
-	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
+	int def_errors;
 	const struct mount_opts *m;
 	char sep = nodefs ? '\n' : ',';
 
@@ -2597,15 +2597,28 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
 
 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
 		int want_set = m->flags & MOPT_SET;
+		int opt_2 = m->flags & MOPT_2;
+		unsigned int mount_opt, def_mount_opt;
+
 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
 		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
 			continue;
-		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
-			continue; /* skip if same as the default */
+
+		if (opt_2) {
+			mount_opt = sbi->s_mount_opt2;
+			def_mount_opt = sbi->s_def_mount_opt2;
+		} else {
+			mount_opt = sbi->s_mount_opt;
+			def_mount_opt = sbi->s_def_mount_opt;
+		}
+		/* skip if same as the default */
+		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
+			continue;
+		/* select Opt_noFoo vs Opt_Foo */
 		if ((want_set &&
-		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
-		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
-			continue; /* select Opt_noFoo vs Opt_Foo */
+		     (mount_opt & m->mount_opt) != m->mount_opt) ||
+		    (!want_set && (mount_opt & m->mount_opt)))
+			continue;
 		SEQ_OPTS_PRINT("%s", token2str(m->token));
 	}
 
@@ -2635,7 +2648,7 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
 	if (nodefs || sbi->s_stripe)
 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
-			(sbi->s_mount_opt ^ def_mount_opt)) {
+			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 			SEQ_OPTS_PUTS("data=journal");
 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
@@ -4340,6 +4353,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		kfree(s_mount_opts);
 	}
 	sbi->s_def_mount_opt = sbi->s_mount_opt;
+	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
 	if (!parse_options((char *) data, sb, &journal_devnum,
 			   &journal_ioprio, 0))
 		goto failed_mount;