On 9/15/22 8:42 PM, Jia Zhu wrote: > 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@xxxxxxxxxxxxx> LGTM. Reviewed-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx> > --- > fs/erofs/super.c | 17 +++++++++++++++++ > fs/erofs/sysfs.c | 19 +++++++++++++++++-- > 2 files changed, 34 insertions(+), 2 deletions(-) > > diff --git a/fs/erofs/super.c b/fs/erofs/super.c > index 24bac58285e8..5e55c4fe6220 100644 > --- a/fs/erofs/super.c > +++ b/fs/erofs/super.c > @@ -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); > } > > @@ -914,6 +928,7 @@ 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; > } > @@ -1067,6 +1082,8 @@ 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; > } > diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c > index c1383e508bbe..341fb43ad587 100644 > --- a/fs/erofs/sysfs.c > +++ b/fs/erofs/sysfs.c > @@ -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; -- Thanks, Jingbo