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: Jia Zhu <zhujia.zj@bytedance.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220918043456.147-7-zhujia.zj@bytedance.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
This commit is contained in:
Jia Zhu 2022-09-18 12:34:56 +08:00 committed by Gao Xiang
parent 7d41963759
commit 2ef1644141
2 changed files with 34 additions and 2 deletions

View File

@ -440,6 +440,7 @@ enum {
Opt_dax_enum, Opt_dax_enum,
Opt_device, Opt_device,
Opt_fsid, Opt_fsid,
Opt_domain_id,
Opt_err 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_enum("dax", Opt_dax_enum, erofs_dax_param_enums),
fsparam_string("device", Opt_device), fsparam_string("device", Opt_device),
fsparam_string("fsid", Opt_fsid), 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; return -ENOMEM;
#else #else
errorfc(fc, "fsid option not supported"); 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 #endif
break; break;
default: default:
@ -702,6 +714,7 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_fs_info = sbi; sb->s_fs_info = sbi;
sbi->opt = ctx->opt; sbi->opt = ctx->opt;
ctx->opt.fsid = NULL; ctx->opt.fsid = NULL;
ctx->opt.domain_id = NULL;
sbi->devs = ctx->devs; sbi->devs = ctx->devs;
ctx->devs = NULL; ctx->devs = NULL;
@ -846,6 +859,7 @@ static void erofs_fc_free(struct fs_context *fc)
erofs_free_dev_context(ctx->devs); erofs_free_dev_context(ctx->devs);
kfree(ctx->opt.fsid); kfree(ctx->opt.fsid);
kfree(ctx->opt.domain_id);
kfree(ctx); kfree(ctx);
} }
@ -916,6 +930,7 @@ static void erofs_kill_sb(struct super_block *sb)
fs_put_dax(sbi->dax_dev, NULL); fs_put_dax(sbi->dax_dev, NULL);
erofs_fscache_unregister_fs(sb); erofs_fscache_unregister_fs(sb);
kfree(sbi->opt.fsid); kfree(sbi->opt.fsid);
kfree(sbi->opt.domain_id);
kfree(sbi); kfree(sbi);
sb->s_fs_info = NULL; 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 #ifdef CONFIG_EROFS_FS_ONDEMAND
if (opt->fsid) if (opt->fsid)
seq_printf(seq, ",fsid=%s", opt->fsid); seq_printf(seq, ",fsid=%s", opt->fsid);
if (opt->domain_id)
seq_printf(seq, ",domain_id=%s", opt->domain_id);
#endif #endif
return 0; return 0;
} }

View File

@ -201,12 +201,27 @@ static struct kobject erofs_feat = {
int erofs_register_sysfs(struct super_block *sb) int erofs_register_sysfs(struct super_block *sb)
{ {
struct erofs_sb_info *sbi = EROFS_SB(sb); struct erofs_sb_info *sbi = EROFS_SB(sb);
char *name;
char *str = NULL;
int err; 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; sbi->s_kobj.kset = &erofs_root;
init_completion(&sbi->s_kobj_unregister); init_completion(&sbi->s_kobj_unregister);
err = kobject_init_and_add(&sbi->s_kobj, &erofs_sb_ktype, NULL, "%s", err = kobject_init_and_add(&sbi->s_kobj, &erofs_sb_ktype, NULL, "%s", name);
erofs_is_fscache_mode(sb) ? sbi->opt.fsid : sb->s_id); kfree(str);
if (err) if (err)
goto put_sb_kobj; goto put_sb_kobj;
return 0; return 0;