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 <[email protected]>
---
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 */
On Wed, 2021-07-21 at 14:44 +0100, David Howells wrote:
> 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 <[email protected]>
> ---
>
> 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,
What's up with the WRITE -> READ change here? Was that a preexisting
bug?
> 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 */
>
>
--
Jeff Layton <[email protected]>
Jeff Layton <[email protected]> wrote:
> > - iov_iter_xarray(&iter, WRITE, &subreq->rreq->mapping->i_pages,
> > + iov_iter_xarray(&iter, READ, &subreq->rreq->mapping->i_pages,
>
> What's up with the WRITE -> READ change here? Was that a preexisting
> bug?
Actually, yes - I need to split that out and send it to Linus.
David