在 2022/9/1 11:31, Gao Xiang 写道:
> 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 <[email protected]>
>> ---
>> 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
>
Thanks for catching this. Maybe something went wrong when I split the
patch. I'll fix it in next version.
Thanks,
Zhu Jia
>> #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