On Wed, Aug 31, 2022 at 08:31:21PM +0800, 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>
> ---
> fs/erofs/internal.h | 1 +
> fs/erofs/super.c | 17 +++++++++++++++++
> 2 files changed, 18 insertions(+)
>
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index cfee49d33b95..fe435d077f1a 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -76,6 +76,7 @@ struct erofs_mount_opts {
> #endif
> unsigned int mount_opt;
> char *fsid;
> + char *domain_id;
> };
>
> struct erofs_dev_context {
> diff --git a/fs/erofs/super.c b/fs/erofs/super.c
> index 3173debeaa5a..fb5a84a07bd5 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:
> + kfree(ctx->opt.domain_id);
> + ctx->opt.domain_id = kstrdup(param->string, GFP_KERNEL);
> + if (!ctx->opt.domain_id)
> + return -ENOMEM;
> +#ifdef CONFIG_EROFS_FS_ONDEMAND
> +#else
> + errorfc(fc, "domain_id option not supported");
Just one question, why not write as below?
#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
Thanks,
Gao Xiang
> #endif
> break;
> default:
> @@ -695,6 +707,7 @@ 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;
>
> @@ -838,6 +851,7 @@ 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);
> }
>
> @@ -892,6 +906,7 @@ static void erofs_kill_sb(struct super_block *sb)
> erofs_fscache_unregister_cookie(&sbi->s_fscache);
> erofs_fscache_unregister_fs(sb);
> kfree(sbi->opt.fsid);
> + kfree(sbi->opt.domain_id);
> kfree(sbi);
> sb->s_fs_info = NULL;
> }
> @@ -1044,6 +1059,8 @@ 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;
> }
> --
> 2.20.1
