Hi, Xiang
On 2026/1/7 14:08, Gao Xiang wrote:
On 2025/12/31 17:01, Hongbo Li wrote:
...
+
+static int erofs_ishare_file_release(struct inode *inode, struct file
*file)
+{
+ struct file *realfile = file->private_data;
+
+ iput(realfile->f_inode);
+ fput(realfile);
+ file->private_data = NULL;
+ return 0;
+}
+
+static ssize_t erofs_ishare_file_read_iter(struct kiocb *iocb,
+ struct iov_iter *to)
+{
+ struct file *realfile = iocb->ki_filp->private_data;
+ struct kiocb dedup_iocb;
+ ssize_t nread;
+
+ if (!iov_iter_count(to))
+ return 0;
+
+ /* fallback to the original file in DIRECT mode */
+ if (iocb->ki_flags & IOCB_DIRECT)
+ realfile = iocb->ki_filp;
+
+ kiocb_clone(&dedup_iocb, iocb, realfile);
+ nread = filemap_read(&dedup_iocb, to, 0);
+ iocb->ki_pos = dedup_iocb.ki_pos;
I think it will not work for the AIO cases.
In order to make it simplified, how about just
allowing sync and non-direct I/O first, and
defering DIO/AIO support later?
Ok, but what about doing the fallback logic:
1. For direct io: fallback to the original file.
2. For AIO: initialize the sync io by init_sync_kiocb (May be we can
just replace kiocb_clone with init_sync_kiocb).
Thanks,
Hongbo
+ file_accessed(iocb->ki_filp);
I don't think it's useful in practice.
Just keep in consistent with filemap_read?
+ return nread;
+}
+
+static int erofs_ishare_mmap(struct file *file, struct vm_area_struct
*vma)
+{
+ struct file *realfile = file->private_data;
+
+ vma_set_file(vma, realfile);
+ return generic_file_readonly_mmap(file, vma);
+}
+
...
@@ -649,6 +659,16 @@ static int erofs_fc_fill_super(struct super_block
*sb, struct fs_context *fc)
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_op = &erofs_sops;
+ if (sbi->domain_id &&
+ (!sbi->fsid && !test_opt(&sbi->opt, INODE_SHARE))) {
+ errorfc(fc, "domain_id should be with fsid or inode_share
option");
+ return -EINVAL;
+ }
Is that really needed?
Ok, I will remove it in next version.
Thanks,
Hongbo
+ if (test_opt(&sbi->opt, DAX_ALWAYS) && test_opt(&sbi->opt,
INODE_SHARE)) {
+ errorfc(fc, "dax is not allowed when inode_share is on");
errorfc(fc, "FSDAX is not allowed when inode_share is on");
Thanks,
Gao Xiang
