Commit 2ef16441 authored by Jia Zhu's avatar Jia Zhu Committed by Gao Xiang
Browse files

erofs: introduce 'domain_id' mount option 



Introduce 'domain_id' mount option to enable shared domain sementics.
In which case, the related cookie is shared if two mountpoints in the
same domain have the same data blob. Users could specify the name of
domain by this mount option.

Signed-off-by: default avatarJia Zhu <zhujia.zj@bytedance.com>
Reviewed-by: default avatarJingbo Xu <jefflexu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220918043456.147-7-zhujia.zj@bytedance.com


Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 7d419637

fs/erofs/super.c

+17 −0
Original line number Diff line number Diff line
@@ -440,6 +440,7 @@ enum { 
	Opt_dax_enum,

	Opt_device,

	Opt_fsid,

	Opt_domain_id,

	Opt_err

};
@@ -465,6 +466,7 @@ static const struct fs_parameter_spec erofs_fs_parameters[] = { 
	fsparam_enum("dax",		Opt_dax_enum, erofs_dax_param_enums),

	fsparam_string("device",	Opt_device),

	fsparam_string("fsid",		Opt_fsid),

	fsparam_string("domain_id",	Opt_domain_id),

	{}

};
@@ -568,6 +570,16 @@ static int erofs_fc_parse_param(struct fs_context *fc, 
			return -ENOMEM;

#else

		errorfc(fc, "fsid option not supported");

#endif

		break;

	case Opt_domain_id:

#ifdef CONFIG_EROFS_FS_ONDEMAND

		kfree(ctx->opt.domain_id);

		ctx->opt.domain_id = kstrdup(param->string, GFP_KERNEL);

		if (!ctx->opt.domain_id)

			return -ENOMEM;

#else

		errorfc(fc, "domain_id option not supported");

#endif

		break;

	default:
@@ -702,6 +714,7 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) 
	sb->s_fs_info = sbi;

	sbi->opt = ctx->opt;

	ctx->opt.fsid = NULL;

	ctx->opt.domain_id = NULL;

	sbi->devs = ctx->devs;

	ctx->devs = NULL;
@@ -846,6 +859,7 @@ static void erofs_fc_free(struct fs_context *fc) 


	erofs_free_dev_context(ctx->devs);

	kfree(ctx->opt.fsid);

	kfree(ctx->opt.domain_id);

	kfree(ctx);

}
@@ -916,6 +930,7 @@ static void erofs_kill_sb(struct super_block *sb) 
	fs_put_dax(sbi->dax_dev, NULL);

	erofs_fscache_unregister_fs(sb);

	kfree(sbi->opt.fsid);

	kfree(sbi->opt.domain_id);

	kfree(sbi);

	sb->s_fs_info = NULL;

}
@@ -1068,6 +1083,8 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root) 
#ifdef CONFIG_EROFS_FS_ONDEMAND

	if (opt->fsid)

		seq_printf(seq, ",fsid=%s", opt->fsid);

	if (opt->domain_id)

		seq_printf(seq, ",domain_id=%s", opt->domain_id);

#endif

	return 0;

}

fs/erofs/sysfs.c

+17 −2
Original line number Diff line number Diff line
@@ -201,12 +201,27 @@ static struct kobject erofs_feat = { 
int erofs_register_sysfs(struct super_block *sb)

{

	struct erofs_sb_info *sbi = EROFS_SB(sb);

	char *name;

	char *str = NULL;

	int err;



	if (erofs_is_fscache_mode(sb)) {

		if (sbi->opt.domain_id) {

			str = kasprintf(GFP_KERNEL, "%s,%s", sbi->opt.domain_id,

					sbi->opt.fsid);

			if (!str)

				return -ENOMEM;

			name = str;

		} else {

			name = sbi->opt.fsid;

		}

	} else {

		name = sb->s_id;

	}

	sbi->s_kobj.kset = &erofs_root;

	init_completion(&sbi->s_kobj_unregister);

	err = kobject_init_and_add(&sbi->s_kobj, &erofs_sb_ktype, NULL, "%s",

			erofs_is_fscache_mode(sb) ? sbi->opt.fsid : sb->s_id);

	err = kobject_init_and_add(&sbi->s_kobj, &erofs_sb_ktype, NULL, "%s", name);

	kfree(str);

	if (err)

		goto put_sb_kobj;

	return 0;