Re: [RFC PATCH v6 3/7] erofs: support domain-specific page cache share

[Hongbo Li]

On 2025/3/1 22:49, Hongzhen Luo wrote:
Only files in the same domain will share the page cache. Also modify
the sysfs related content in preparation for the upcoming page cache
share feature.

Signed-off-by: Hongzhen Luo <hongz...@linux.alibaba.com>
---
  fs/erofs/super.c | 12 ++++++++----
  1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 6af02cc8b8c6..ceab0c29b061 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -489,6 +489,8 @@ static int erofs_fc_parse_param(struct fs_context *fc,
                if (!sbi->fsid)
                        return -ENOMEM;
                break;
+#endif
+#if defined(CONFIG_EROFS_FS_ONDEMAND) || defined(CONFIG_EROFS_FS_INODE_SHARE)
        case Opt_domain_id:
                kfree(sbi->domain_id);
                sbi->domain_id = kstrdup(param->string, GFP_KERNEL);
@@ -558,16 +560,16 @@ static void erofs_set_sysfs_name(struct super_block *sb)
  {
        struct erofs_sb_info *sbi = EROFS_SB(sb);
  
-	if (sbi->domain_id)
+       if (sbi->domain_id && !sbi->ishare_key)
                super_set_sysfs_name_generic(sb, "%s,%s", sbi->domain_id,
                                             sbi->fsid);
        else if (sbi->fsid)
                super_set_sysfs_name_generic(sb, "%s", sbi->fsid);
-       else if (erofs_is_fileio_mode(sbi))
I think there is no need to change this, because the inode page cache is 
just a mode for reading, not like a super block type.
+       else if (!sb->s_bdi || !sb->s_bdi->dev)
+               super_set_sysfs_name_id(sb);
+       else
                super_set_sysfs_name_generic(sb, "%s",
                                             bdi_dev_name(sb->s_bdi));
-       else
-               super_set_sysfs_name_id(sb);
  }
  
  static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
@@ -965,6 +967,8 @@ static int erofs_show_options(struct seq_file *seq, struct 
dentry *root)
  #ifdef CONFIG_EROFS_FS_ONDEMAND
        if (sbi->fsid)
                seq_printf(seq, ",fsid=%s", sbi->fsid);
+#endif
+#if defined(CONFIG_EROFS_FS_ONDEMAND) || defined(CONFIG_EROFS_FS_INODE_SHARE)
        if (sbi->domain_id)
                seq_printf(seq, ",domain_id=%s", sbi->domain_id);
  #endif