Re: [External] Re: [PATCH V2 3/5] erofs: add 'domain_id' prefix when register sysfs

Jia Zhu <zhujia.zj@xxxxxxxxxxxxx> · Tue, 13 Sep 2022 12:35:58 +0800

在 2022/9/9 17:26, JeffleXu 写道:


On 9/9/22 5:23 PM, JeffleXu wrote:


On 9/2/22 6:53 PM, Jia Zhu wrote:
In shared domain mount procedure, add 'domain_id' prefix to register
sysfs entry. Thus we could distinguish mounts that don't use shared
domain.

Signed-off-by: Jia Zhu <zhujia.zj@xxxxxxxxxxxxx>
---
  fs/erofs/sysfs.c | 11 ++++++++++-
  1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
index c1383e508bbe..c0031d7bd817 100644
--- a/fs/erofs/sysfs.c
+++ b/fs/erofs/sysfs.c
@@ -201,12 +201,21 @@ static struct kobject erofs_feat = {
  int erofs_register_sysfs(struct super_block *sb)
  {
  	struct erofs_sb_info *sbi = EROFS_SB(sb);
+	char *name = NULL;
  	int err;
  
+	if (erofs_is_fscache_mode(sb)) {
+		name = kasprintf(GFP_KERNEL, "%s%s%s", sbi->opt.domain_id ?
+				sbi->opt.domain_id : "", sbi->opt.domain_id ? "," : "",
+				sbi->opt.fsid);
+		if (!name)
+			return -ENOMEM;
+	}


How about:

name = erofs_is_fscache_mode(sb) ? sbi->opt.fsid : sb->s_id;
if (sbi->opt.domain_id) {
	str = kasprintf(GFP_KERNEL, "%s,%s", sbi->opt.domain_id, sbi->opt.fsid);
	name = str;
}

Another choice:

if (erofs_is_fscache_mode(sb)) {
	if (sbi->opt.domain_id) {
		str = kasprintf(GFP_KERNEL, "%s,%s", sbi->opt.domain_id, sbi->opt.fsid);
		name = str;
	} else {
		name = sbi->opt.fsid;
	}
} else {
	name = sb->s_id;
}


Thanks for your advise, this version looks more intuitive. I'll apply it
in next version.




  	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);
+			name ? name : sb->s_id);

	kobject_init_and_add(..., "%s", name);
	kfree(str);

though it's still not such straightforward...

Any better idea?


+	kfree(name);
  	if (err)
  		goto put_sb_kobj;
  	return 0;








