Subject: linux-next: manual merge of the vfs tree with the erofs tree

From: Stephen Rothwell <[email-masked]>
Date: Mon, 5 Dec 2022 09:24:15 +1100

Hi all,

Today's linux-next merge of the vfs tree got a conflict in:

  fs/erofs/fscache.c

between commits:

  89175ef1262d ("erofs: switch to prepare_ondemand_read() in fscache mode")
  89175ef1262d ("erofs: switch to prepare_ondemand_read() in fscache mode")

from the erofs tree and commit:

  89175ef1262d ("erofs: switch to prepare_ondemand_read() in fscache mode")

from the vfs tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc fs/erofs/fscache.c
index f14886c479bd,4c837be3b6e3..000000000000
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@@ -126,28 -159,47 +126,28 @@@ static int erofs_fscache_read_folios_as
  
  	ret = fscache_begin_read_operation(cres, cookie);
  	if (ret)
 -		goto out;
 +		return ret;
  
  	while (done < len) {
 -		subreq = kzalloc(sizeof(struct netfs_io_subrequest),
 -				 GFP_KERNEL);
 -		if (subreq) {
 -			INIT_LIST_HEAD(&subreq->rreq_link);
 -			refcount_set(&subreq->ref, 2);
 -			subreq->rreq = rreq;
 -			refcount_inc(&rreq->ref);
 -		} else {
 -			ret = -ENOMEM;
 -			goto out;
 -		}
 -
 -		subreq->start = pstart + done;
 -		subreq->len	=  len - done;
 -		subreq->flags = 1 << NETFS_SREQ_ONDEMAND;
 +		loff_t sstart = pstart + done;
 +		size_t slen = len - done;
 +		unsigned long flags = 1 << NETFS_SREQ_ONDEMAND;
  
 -		list_add_tail(&subreq->rreq_link, &rreq->subrequests);
 -
 -		source = cres->ops->prepare_read(subreq, LLONG_MAX);
 -		if (WARN_ON(subreq->len == 0))
 +		source = cres->ops->prepare_ondemand_read(cres,
 +				sstart, &slen, LLONG_MAX, &flags, 0);
 +		if (WARN_ON(slen == 0))
  			source = NETFS_INVALID_READ;
  		if (source != NETFS_READ_FROM_CACHE) {
 -			erofs_err(sb, "failed to fscache prepare_read (source %d)",
 -				  source);
 -			ret = -EIO;
 -			subreq->error = ret;
 -			erofs_fscache_put_subrequest(subreq);
 -			goto out;
 +			erofs_err(sb, "failed to fscache prepare_read (source %d)", source);
 +			return -EIO;
  		}
  
 -		atomic_inc(&rreq->nr_outstanding);
 +		refcount_inc(&req->ref);
- 		iov_iter_xarray(&iter, READ, &req->mapping->i_pages,
++		iov_iter_xarray(&iter, ITER_DEST, &req->mapping->i_pages,
 +				lstart + done, slen);
  
 -		iov_iter_xarray(&iter, ITER_DEST, &rreq->mapping->i_pages,
 -				start + done, subreq->len);
 -
 -		ret = fscache_read(cres, subreq->start, &iter,
 -				   NETFS_READ_HOLE_FAIL,
 -				   erofc_fscache_subreq_complete, subreq);
 +		ret = fscache_read(cres, sstart, &iter, NETFS_READ_HOLE_FAIL,
 +				   erofs_fscache_subreq_complete, req);
  		if (ret == -EIOCBQUEUED)
  			ret = 0;
  		if (ret) {
@@@ -233,19 -297,17 +233,19 @@@ static int erofs_fscache_data_read_slic
  		}
  		iov_iter_zero(PAGE_SIZE - size, &iter);
  		erofs_put_metabuf(&buf);
 -		return PAGE_SIZE;
 +		primary->submitted += PAGE_SIZE;
 +		return 0;
  	}
  
 +	count = primary->len - primary->submitted;
  	if (!(map.m_flags & EROFS_MAP_MAPPED)) {
- 		iov_iter_xarray(&iter, READ, &mapping->i_pages, pos, count);
 -		count = len;
+ 		iov_iter_xarray(&iter, ITER_DEST, &mapping->i_pages, pos, count);
  		iov_iter_zero(count, &iter);
 -		return count;
 +		primary->submitted += count;
 +		return 0;
  	}
  
 -	count = min_t(size_t, map.m_llen - (pos - map.m_la), len);
 +	count = min_t(size_t, map.m_llen - (pos - map.m_la), count);
  	DBG_BUGON(!count || count % PAGE_SIZE);
  
  	mdev = (struct erofs_map_dev) {