Add an iov_iter to the read subrequest and set it up to define the
destination buffer to write into. This will allow future patches to point
to a bounce buffer instead for purposes of handling oversize writes,
decryption (where we want to save the encrypted data to the cache) and
decompression.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
fs/afs/file.c | 6 +-----
fs/netfs/read_helper.c | 5 ++++-
include/linux/netfs.h | 2 ++
3 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/fs/afs/file.c b/fs/afs/file.c
index c9c21ad0e7c9..ca529f23515a 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -319,11 +319,7 @@ static void afs_req_issue_op(struct netfs_read_subrequest *subreq)
fsreq->len = subreq->len - subreq->transferred;
fsreq->key = subreq->rreq->netfs_priv;
fsreq->vnode = vnode;
- fsreq->iter = &fsreq->def_iter;
-
- iov_iter_xarray(&fsreq->def_iter, READ,
- &fsreq->vnode->vfs_inode.i_mapping->i_pages,
- fsreq->pos, fsreq->len);
+ fsreq->iter = &subreq->iter;
afs_fetch_data(fsreq->vnode, fsreq);
}
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 0b6cd3b8734c..715f3e9c380d 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c
@@ -150,7 +150,7 @@ static void netfs_clear_unread(struct netfs_read_subrequest *subreq)
{
struct iov_iter iter;
- iov_iter_xarray(&iter, WRITE, &subreq->rreq->mapping->i_pages,
+ iov_iter_xarray(&iter, READ, &subreq->rreq->mapping->i_pages,
subreq->start + subreq->transferred,
subreq->len - subreq->transferred);
iov_iter_zero(iov_iter_count(&iter), &iter);
@@ -745,6 +745,9 @@ netfs_rreq_prepare_read(struct netfs_read_request *rreq,
if (WARN_ON(subreq->len == 0))
source = NETFS_INVALID_READ;
+ iov_iter_xarray(&subreq->iter, READ, &rreq->mapping->i_pages,
+ subreq->start, subreq->len);
+
out:
subreq->source = source;
trace_netfs_sreq(subreq, netfs_sreq_trace_prepare);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index fe9887768292..5e4fafcc9480 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -17,6 +17,7 @@
#include <linux/workqueue.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
+#include <linux/uio.h>
/*
* Overload PG_private_2 to give us PG_fscache - this is used to indicate that
@@ -112,6 +113,7 @@ struct netfs_cache_resources {
struct netfs_read_subrequest {
struct netfs_read_request *rreq; /* Supervising read request */
struct list_head rreq_link; /* Link in rreq->subrequests */
+ struct iov_iter iter; /* Iterator for this subrequest */
loff_t start; /* Where to start the I/O */
size_t len; /* Size of the I/O */
size_t transferred; /* Amount of data transferred */
