From 2ef164414123fcf574aff7a0be5f71f7e60a3fec Mon Sep 17 00:00:00 2001 From: Jia Zhu Date: Sun, 18 Sep 2022 12:34:56 +0800 Subject: [PATCH] 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 Reviewed-by: Jingbo Xu Link: https://lore.kernel.org/r/20220918043456.147-7-zhujia.zj@bytedance.com Signed-off-by: Gao Xiang --- 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 ab74618..9f7fe6c 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), {} }; @@ -570,6 +572,16 @@ static int erofs_fc_parse_param(struct fs_context *fc, 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: return -ENOPARAM; } @@ -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; } diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c index c1383e5..341fb43a 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; -- 2.7.4