| Message ID | 162687509306.276387.7579641363406546284.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,01/12] afs: Sort out symlink reading | expand |
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 <dhowells@redhat.com> > --- > > 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 <jlayton@redhat.com> 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
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 */
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@redhat.com> --- fs/afs/file.c | 6 +----- fs/netfs/read_helper.c | 5 ++++- include/linux/netfs.h | 2 ++ 3 files changed, 7 insertions(+), 6 deletions(-)