1 files changed, 161 insertions, 730 deletions

diff --git a/fs/afs/write.c b/fs/afs/write.c
index 72efcfcf9f95..93ad86ff3345 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* handling of writes to regular files and writing back to the server
  *
  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */
 
 #include <linux/backing-dev.h>
@@ -15,368 +11,146 @@
 #include <linux/pagemap.h>
 #include <linux/writeback.h>
 #include <linux/pagevec.h>
+#include <linux/netfs.h>
+#include <trace/events/netfs.h>
 #include "internal.h"
 
 /*
- * mark a page as having been made dirty and thus needing writeback
- */
-int afs_set_page_dirty(struct page *page)
-{
-	_enter("");
-	return __set_page_dirty_nobuffers(page);
-}
-
-/*
- * partly or wholly fill a page that's under preparation for writing
+ * completion of write to server
  */
-static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
-			 loff_t pos, unsigned int len, struct page *page)
+static void afs_pages_written_back(struct afs_vnode *vnode, loff_t start, unsigned int len)
 {
-	struct afs_read *req;
-	size_t p;
-	void *data;
-	int ret;
-
-	_enter(",,%llu", (unsigned long long)pos);
-
-	if (pos >= vnode->vfs_inode.i_size) {
-		p = pos & ~PAGE_MASK;
-		ASSERTCMP(p + len, <=, PAGE_SIZE);
-		data = kmap(page);
-		memset(data + p, 0, len);
-		kunmap(page);
-		return 0;
-	}
-
-	req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
-		      GFP_KERNEL);
-	if (!req)
-		return -ENOMEM;
-
-	refcount_set(&req->usage, 1);
-	req->pos = pos;
-	req->len = len;
-	req->nr_pages = 1;
-	req->pages = req->array;
-	req->pages[0] = page;
-	get_page(page);
-
-	ret = afs_fetch_data(vnode, key, req);
-	afs_put_read(req);
-	if (ret < 0) {
-		if (ret == -ENOENT) {
-			_debug("got NOENT from server"
-			       " - marking file deleted and stale");
-			set_bit(AFS_VNODE_DELETED, &vnode->flags);
-			ret = -ESTALE;
-		}
-	}
+	_enter("{%llx:%llu},{%x @%llx}",
+	       vnode->fid.vid, vnode->fid.vnode, len, start);
 
-	_leave(" = %d", ret);
-	return ret;
+	afs_prune_wb_keys(vnode);
+	_leave("");
 }
 
 /*
- * prepare to perform part of a write to a page
+ * Find a key to use for the writeback.  We cached the keys used to author the
+ * writes on the vnode.  wreq->netfs_priv2 will contain the last writeback key
+ * record used or NULL and we need to start from there if it's set.
+ * wreq->netfs_priv will be set to the key itself or NULL.
  */
-int afs_write_begin(struct file *file, struct address_space *mapping,
-		    loff_t pos, unsigned len, unsigned flags,
-		    struct page **pagep, void **fsdata)
+static void afs_get_writeback_key(struct netfs_io_request *wreq)
 {
-	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
-	struct page *page;
-	struct key *key = afs_file_key(file);
-	unsigned long priv;
-	unsigned f, from = pos & (PAGE_SIZE - 1);
-	unsigned t, to = from + len;
-	pgoff_t index = pos >> PAGE_SHIFT;
-	int ret;
+	struct afs_wb_key *wbk, *old = wreq->netfs_priv2;
+	struct afs_vnode *vnode = AFS_FS_I(wreq->inode);
 
-	_enter("{%llx:%llu},{%lx},%u,%u",
-	       vnode->fid.vid, vnode->fid.vnode, index, from, to);
+	key_put(wreq->netfs_priv);
+	wreq->netfs_priv = NULL;
+	wreq->netfs_priv2 = NULL;
 
-	/* We want to store information about how much of a page is altered in
-	 * page->private.
-	 */
-	BUILD_BUG_ON(PAGE_SIZE > 32768 && sizeof(page->private) < 8);
-
-	page = grab_cache_page_write_begin(mapping, index, flags);
-	if (!page)
-		return -ENOMEM;
-
-	if (!PageUptodate(page) && len != PAGE_SIZE) {
-		ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page);
-		if (ret < 0) {
-			unlock_page(page);
-			put_page(page);
-			_leave(" = %d [prep]", ret);
-			return ret;
-		}
-		SetPageUptodate(page);
-	}
-
-	/* page won't leak in error case: it eventually gets cleaned off LRU */
-	*pagep = page;
-
-try_again:
-	/* See if this page is already partially written in a way that we can
-	 * merge the new write with.
-	 */
-	t = f = 0;
-	if (PagePrivate(page)) {
-		priv = page_private(page);
-		f = priv & AFS_PRIV_MAX;
-		t = priv >> AFS_PRIV_SHIFT;
-		ASSERTCMP(f, <=, t);
-	}
+	spin_lock(&vnode->wb_lock);
+	if (old)
+		wbk = list_next_entry(old, vnode_link);
+	else
+		wbk = list_first_entry(&vnode->wb_keys, struct afs_wb_key, vnode_link);
 
-	if (f != t) {
-		if (PageWriteback(page)) {
-			trace_afs_page_dirty(vnode, tracepoint_string("alrdy"),
-					     page->index, priv);
-			goto flush_conflicting_write;
+	list_for_each_entry_from(wbk, &vnode->wb_keys, vnode_link) {
+		_debug("wbk %u", key_serial(wbk->key));
+		if (key_validate(wbk->key) == 0) {
+			refcount_inc(&wbk->usage);
+			wreq->netfs_priv = key_get(wbk->key);
+			wreq->netfs_priv2 = wbk;
+			_debug("USE WB KEY %u", key_serial(wbk->key));
+			break;
 		}
-		/* If the file is being filled locally, allow inter-write
-		 * spaces to be merged into writes.  If it's not, only write
-		 * back what the user gives us.
-		 */
-		if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) &&
-		    (to < f || from > t))
-			goto flush_conflicting_write;
-		if (from < f)
-			f = from;
-		if (to > t)
-			t = to;
-	} else {
-		f = from;
-		t = to;
 	}
 
-	priv = (unsigned long)t << AFS_PRIV_SHIFT;
-	priv |= f;
-	trace_afs_page_dirty(vnode, tracepoint_string("begin"),
-			     page->index, priv);
-	SetPagePrivate(page);
-	set_page_private(page, priv);
-	_leave(" = 0");
-	return 0;
-
-	/* The previous write and this write aren't adjacent or overlapping, so
-	 * flush the page out.
-	 */
-flush_conflicting_write:
-	_debug("flush conflict");
-	ret = write_one_page(page);
-	if (ret < 0) {
-		_leave(" = %d", ret);
-		return ret;
-	}
+	spin_unlock(&vnode->wb_lock);
 
-	ret = lock_page_killable(page);
-	if (ret < 0) {
-		_leave(" = %d", ret);
-		return ret;
-	}
-	goto try_again;
+	afs_put_wb_key(old);
 }
 
-/*
- * finalise part of a write to a page
- */
-int afs_write_end(struct file *file, struct address_space *mapping,
-		  loff_t pos, unsigned len, unsigned copied,
-		  struct page *page, void *fsdata)
+static void afs_store_data_success(struct afs_operation *op)
 {
-	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
-	struct key *key = afs_file_key(file);
-	loff_t i_size, maybe_i_size;
-	int ret;
-
-	_enter("{%llx:%llu},{%lx}",
-	       vnode->fid.vid, vnode->fid.vnode, page->index);
-
-	maybe_i_size = pos + copied;
-
-	i_size = i_size_read(&vnode->vfs_inode);
-	if (maybe_i_size > i_size) {
-		spin_lock(&vnode->wb_lock);
-		i_size = i_size_read(&vnode->vfs_inode);
-		if (maybe_i_size > i_size)
-			i_size_write(&vnode->vfs_inode, maybe_i_size);
-		spin_unlock(&vnode->wb_lock);
-	}
+	struct afs_vnode *vnode = op->file[0].vnode;
 
-	if (!PageUptodate(page)) {
-		if (copied < len) {
-			/* Try and load any missing data from the server.  The
-			 * unmarshalling routine will take care of clearing any
-			 * bits that are beyond the EOF.
-			 */
-			ret = afs_fill_page(vnode, key, pos + copied,
-					    len - copied, page);
-			if (ret < 0)
-				goto out;
-		}
-		SetPageUptodate(page);
+	op->ctime = op->file[0].scb.status.mtime_client;
+	afs_vnode_commit_status(op, &op->file[0]);
+	if (!afs_op_error(op)) {
+		afs_pages_written_back(vnode, op->store.pos, op->store.size);
+		afs_stat_v(vnode, n_stores);
+		atomic_long_add(op->store.size, &afs_v2net(vnode)->n_store_bytes);
 	}
-
-	set_page_dirty(page);
-	if (PageDirty(page))
-		_debug("dirtied");
-	ret = copied;
-
-out:
-	unlock_page(page);
-	put_page(page);
-	return ret;
 }
 
-/*
- * kill all the pages in the given range
- */
-static void afs_kill_pages(struct address_space *mapping,
-			   pgoff_t first, pgoff_t last)
-{
-	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
-	struct pagevec pv;
-	unsigned count, loop;
-
-	_enter("{%llx:%llu},%lx-%lx",
-	       vnode->fid.vid, vnode->fid.vnode, first, last);
-
-	pagevec_init(&pv);
-
-	do {
-		_debug("kill %lx-%lx", first, last);
-
-		count = last - first + 1;
-		if (count > PAGEVEC_SIZE)
-			count = PAGEVEC_SIZE;
-		pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
-		ASSERTCMP(pv.nr, ==, count);
-
-		for (loop = 0; loop < count; loop++) {
-			struct page *page = pv.pages[loop];
-			ClearPageUptodate(page);
-			SetPageError(page);
-			end_page_writeback(page);
-			if (page->index >= first)
-				first = page->index + 1;
-			lock_page(page);
-			generic_error_remove_page(mapping, page);
-		}
-
-		__pagevec_release(&pv);
-	} while (first <= last);
-
-	_leave("");
-}
+static const struct afs_operation_ops afs_store_data_operation = {
+	.issue_afs_rpc	= afs_fs_store_data,
+	.issue_yfs_rpc	= yfs_fs_store_data,
+	.success	= afs_store_data_success,
+};
 
 /*
- * Redirty all the pages in a given range.
+ * Prepare a subrequest to write to the server.  This sets the max_len
+ * parameter.
  */
-static void afs_redirty_pages(struct writeback_control *wbc,
-			      struct address_space *mapping,
-			      pgoff_t first, pgoff_t last)
+void afs_prepare_write(struct netfs_io_subrequest *subreq)
 {
-	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
-	struct pagevec pv;
-	unsigned count, loop;
-
-	_enter("{%llx:%llu},%lx-%lx",
-	       vnode->fid.vid, vnode->fid.vnode, first, last);
-
-	pagevec_init(&pv);
-
-	do {
-		_debug("redirty %lx-%lx", first, last);
-
-		count = last - first + 1;
-		if (count > PAGEVEC_SIZE)
-			count = PAGEVEC_SIZE;
-		pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
-		ASSERTCMP(pv.nr, ==, count);
+	struct netfs_io_stream *stream = &subreq->rreq->io_streams[subreq->stream_nr];
 
-		for (loop = 0; loop < count; loop++) {
-			struct page *page = pv.pages[loop];
-
-			redirty_page_for_writepage(wbc, page);
-			end_page_writeback(page);
-			if (page->index >= first)
-				first = page->index + 1;
-		}
-
-		__pagevec_release(&pv);
-	} while (first <= last);
-
-	_leave("");
+	//if (test_bit(NETFS_SREQ_RETRYING, &subreq->flags))
+	//	subreq->max_len = 512 * 1024;
+	//else
+	stream->sreq_max_len = 256 * 1024 * 1024;
 }
 
 /*
- * write to a file
+ * Issue a subrequest to write to the server.
  */
-static int afs_store_data(struct address_space *mapping,
-			  pgoff_t first, pgoff_t last,
-			  unsigned offset, unsigned to)
+static void afs_issue_write_worker(struct work_struct *work)
 {
-	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
-	struct afs_fs_cursor fc;
-	struct afs_wb_key *wbk = NULL;
-	struct list_head *p;
-	int ret = -ENOKEY, ret2;
-
-	_enter("%s{%llx:%llu.%u},%lx,%lx,%x,%x",
+	struct netfs_io_subrequest *subreq = container_of(work, struct netfs_io_subrequest, work);
+	struct netfs_io_request *wreq = subreq->rreq;
+	struct afs_operation *op;
+	struct afs_vnode *vnode = AFS_FS_I(wreq->inode);
+	unsigned long long pos = subreq->start + subreq->transferred;
+	size_t len = subreq->len - subreq->transferred;
+	int ret = -ENOKEY;
+
+	_enter("R=%x[%x],%s{%llx:%llu.%u},%llx,%zx",
+	       wreq->debug_id, subreq->debug_index,
 	       vnode->volume->name,
 	       vnode->fid.vid,
 	       vnode->fid.vnode,
 	       vnode->fid.unique,
-	       first, last, offset, to);
+	       pos, len);
 
-	spin_lock(&vnode->wb_lock);
-	p = vnode->wb_keys.next;
+#if 0 // Error injection
+	if (subreq->debug_index == 3)
+		return netfs_write_subrequest_terminated(subreq, -ENOANO);
 
-	/* Iterate through the list looking for a valid key to use. */
-try_next_key:
-	while (p != &vnode->wb_keys) {
-		wbk = list_entry(p, struct afs_wb_key, vnode_link);
-		_debug("wbk %u", key_serial(wbk->key));
-		ret2 = key_validate(wbk->key);
-		if (ret2 == 0)
-			goto found_key;
-		if (ret == -ENOKEY)
-			ret = ret2;
-		p = p->next;
+	if (!subreq->retry_count) {
+		set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags);
+		return netfs_write_subrequest_terminated(subreq, -EAGAIN);
 	}
+#endif
 
-	spin_unlock(&vnode->wb_lock);
-	afs_put_wb_key(wbk);
-	_leave(" = %d [no keys]", ret);
-	return ret;
-
-found_key:
-	refcount_inc(&wbk->usage);
-	spin_unlock(&vnode->wb_lock);
+	op = afs_alloc_operation(wreq->netfs_priv, vnode->volume);
+	if (IS_ERR(op))
+		return netfs_write_subrequest_terminated(subreq, -EAGAIN);
 
-	_debug("USE WB KEY %u", key_serial(wbk->key));
+	afs_op_set_vnode(op, 0, vnode);
+	op->file[0].dv_delta	= 1;
+	op->file[0].modification = true;
+	op->store.pos		= pos;
+	op->store.size		= len;
+	op->flags		|= AFS_OPERATION_UNINTR;
+	op->ops			= &afs_store_data_operation;
 
-	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, vnode, wbk->key)) {
-		while (afs_select_fileserver(&fc)) {
-			fc.cb_break = afs_calc_vnode_cb_break(vnode);
-			afs_fs_store_data(&fc, mapping, first, last, offset, to);
-		}
+	afs_begin_vnode_operation(op);
 
-		afs_check_for_remote_deletion(&fc, fc.vnode);
-		afs_vnode_commit_status(&fc, vnode, fc.cb_break);
-		ret = afs_end_vnode_operation(&fc);
-	}
+	op->store.write_iter	= &subreq->io_iter;
+	op->store.i_size	= umax(pos + len, vnode->netfs.remote_i_size);
+	op->mtime		= inode_get_mtime(&vnode->netfs.inode);
 
+	afs_wait_for_operation(op);
+	ret = afs_put_operation(op);
 	switch (ret) {
 	case 0:
-		afs_stat_v(vnode, n_stores);
-		atomic_long_add((last * PAGE_SIZE + to) -
-				(first * PAGE_SIZE + offset),
-				&afs_v2net(vnode)->n_store_bytes);
+		__set_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags);
 		break;
 	case -EACCES:
 	case -EPERM:
@@ -384,364 +158,91 @@ found_key:
 	case -EKEYEXPIRED:
 	case -EKEYREJECTED:
 	case -EKEYREVOKED:
-		_debug("next");
-		spin_lock(&vnode->wb_lock);
-		p = wbk->vnode_link.next;
-		afs_put_wb_key(wbk);
-		goto try_next_key;
+		/* If there are more keys we can try, use the retry algorithm
+		 * to rotate the keys.
+		 */
+		if (wreq->netfs_priv2)
+			set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags);
+		break;
 	}
 
-	afs_put_wb_key(wbk);
-	_leave(" = %d", ret);
-	return ret;
+	netfs_write_subrequest_terminated(subreq, ret < 0 ? ret : subreq->len);
+}
+
+void afs_issue_write(struct netfs_io_subrequest *subreq)
+{
+	subreq->work.func = afs_issue_write_worker;
+	if (!queue_work(system_dfl_wq, &subreq->work))
+		WARN_ON_ONCE(1);
 }
 
 /*
- * Synchronously write back the locked page and any subsequent non-locked dirty
- * pages.
+ * Writeback calls this when it finds a folio that needs uploading.  This isn't
+ * called if writeback only has copy-to-cache to deal with.
  */
-static int afs_write_back_from_locked_page(struct address_space *mapping,
-					   struct writeback_control *wbc,
-					   struct page *primary_page,
-					   pgoff_t final_page)
+void afs_begin_writeback(struct netfs_io_request *wreq)
 {
-	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
-	struct page *pages[8], *page;
-	unsigned long count, priv;
-	unsigned n, offset, to, f, t;
-	pgoff_t start, first, last;
-	int loop, ret;
-
-	_enter(",%lx", primary_page->index);
-
-	count = 1;
-	if (test_set_page_writeback(primary_page))
-		BUG();
-
-	/* Find all consecutive lockable dirty pages that have contiguous
-	 * written regions, stopping when we find a page that is not
-	 * immediately lockable, is not dirty or is missing, or we reach the
-	 * end of the range.
-	 */
-	start = primary_page->index;
-	priv = page_private(primary_page);
-	offset = priv & AFS_PRIV_MAX;
-	to = priv >> AFS_PRIV_SHIFT;
-	trace_afs_page_dirty(vnode, tracepoint_string("store"),
-			     primary_page->index, priv);
-
-	WARN_ON(offset == to);
-	if (offset == to)
-		trace_afs_page_dirty(vnode, tracepoint_string("WARN"),
-				     primary_page->index, priv);
-
-	if (start >= final_page ||
-	    (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)))
-		goto no_more;
-
-	start++;
-	do {
-		_debug("more %lx [%lx]", start, count);
-		n = final_page - start + 1;
-		if (n > ARRAY_SIZE(pages))
-			n = ARRAY_SIZE(pages);
-		n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages);
-		_debug("fgpc %u", n);
-		if (n == 0)
-			goto no_more;
-		if (pages[0]->index != start) {
-			do {
-				put_page(pages[--n]);
-			} while (n > 0);
-			goto no_more;
-		}
-
-		for (loop = 0; loop < n; loop++) {
-			page = pages[loop];
-			if (to != PAGE_SIZE &&
-			    !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))
-				break;
-			if (page->index > final_page)
-				break;
-			if (!trylock_page(page))
-				break;
-			if (!PageDirty(page) || PageWriteback(page)) {
-				unlock_page(page);
-				break;
-			}
-
-			priv = page_private(page);
-			f = priv & AFS_PRIV_MAX;
-			t = priv >> AFS_PRIV_SHIFT;
-			if (f != 0 &&
-			    !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) {
-				unlock_page(page);
-				break;
-			}
-			to = t;
-
-			trace_afs_page_dirty(vnode, tracepoint_string("store+"),
-					     page->index, priv);
-
-			if (!clear_page_dirty_for_io(page))
-				BUG();
-			if (test_set_page_writeback(page))
-				BUG();
-			unlock_page(page);
-			put_page(page);
-		}
-		count += loop;
-		if (loop < n) {
-			for (; loop < n; loop++)
-				put_page(pages[loop]);
-			goto no_more;
-		}
-
-		start += loop;
-	} while (start <= final_page && count < 65536);
-
-no_more:
-	/* We now have a contiguous set of dirty pages, each with writeback
-	 * set; the first page is still locked at this point, but all the rest
-	 * have been unlocked.
-	 */
-	unlock_page(primary_page);
-
-	first = primary_page->index;
-	last = first + count - 1;
-
-	_debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to);
+	if (S_ISREG(wreq->inode->i_mode))
+		afs_get_writeback_key(wreq);
+}
 
-	ret = afs_store_data(mapping, first, last, offset, to);
-	switch (ret) {
-	case 0:
-		ret = count;
+/*
+ * Prepare to retry the writes in request.  Use this to try rotating the
+ * available writeback keys.
+ */
+void afs_retry_request(struct netfs_io_request *wreq, struct netfs_io_stream *stream)
+{
+	struct netfs_io_subrequest *subreq =
+		list_first_entry(&stream->subrequests,
+				 struct netfs_io_subrequest, rreq_link);
+
+	switch (wreq->origin) {
+	case NETFS_READAHEAD:
+	case NETFS_READPAGE:
+	case NETFS_READ_GAPS:
+	case NETFS_READ_SINGLE:
+	case NETFS_READ_FOR_WRITE:
+	case NETFS_UNBUFFERED_READ:
+	case NETFS_DIO_READ:
+		return;
+	default:
 		break;
+	}
 
-	default:
-		pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret);
-		/* Fall through */
+	switch (subreq->error) {
 	case -EACCES:
 	case -EPERM:
 	case -ENOKEY:
 	case -EKEYEXPIRED:
 	case -EKEYREJECTED:
 	case -EKEYREVOKED:
-		afs_redirty_pages(wbc, mapping, first, last);
-		mapping_set_error(mapping, ret);
-		break;
-
-	case -EDQUOT:
-	case -ENOSPC:
-		afs_redirty_pages(wbc, mapping, first, last);
-		mapping_set_error(mapping, -ENOSPC);
-		break;
-
-	case -EROFS:
-	case -EIO:
-	case -EREMOTEIO:
-	case -EFBIG:
-	case -ENOENT:
-	case -ENOMEDIUM:
-	case -ENXIO:
-		trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail);
-		afs_kill_pages(mapping, first, last);
-		mapping_set_error(mapping, ret);
+		afs_get_writeback_key(wreq);
+		if (!wreq->netfs_priv)
+			stream->failed = true;
 		break;
 	}
-
-	_leave(" = %d", ret);
-	return ret;
-}
-
-/*
- * write a page back to the server
- * - the caller locked the page for us
- */
-int afs_writepage(struct page *page, struct writeback_control *wbc)
-{
-	int ret;
-
-	_enter("{%lx},", page->index);
-
-	ret = afs_write_back_from_locked_page(page->mapping, wbc, page,
-					      wbc->range_end >> PAGE_SHIFT);
-	if (ret < 0) {
-		_leave(" = %d", ret);
-		return 0;
-	}
-
-	wbc->nr_to_write -= ret;
-
-	_leave(" = 0");
-	return 0;
-}
-
-/*
- * write a region of pages back to the server
- */
-static int afs_writepages_region(struct address_space *mapping,
-				 struct writeback_control *wbc,
-				 pgoff_t index, pgoff_t end, pgoff_t *_next)
-{
-	struct page *page;
-	int ret, n;
-
-	_enter(",,%lx,%lx,", index, end);
-
-	do {
-		n = find_get_pages_range_tag(mapping, &index, end,
-					PAGECACHE_TAG_DIRTY, 1, &page);
-		if (!n)
-			break;
-
-		_debug("wback %lx", page->index);
-
-		/*
-		 * at this point we hold neither the i_pages lock nor the
-		 * page lock: the page may be truncated or invalidated
-		 * (changing page->mapping to NULL), or even swizzled
-		 * back from swapper_space to tmpfs file mapping
-		 */
-		ret = lock_page_killable(page);
-		if (ret < 0) {
-			put_page(page);
-			_leave(" = %d", ret);
-			return ret;
-		}
-
-		if (page->mapping != mapping || !PageDirty(page)) {
-			unlock_page(page);
-			put_page(page);
-			continue;
-		}
-
-		if (PageWriteback(page)) {
-			unlock_page(page);
-			if (wbc->sync_mode != WB_SYNC_NONE)
-				wait_on_page_writeback(page);
-			put_page(page);
-			continue;
-		}
-
-		if (!clear_page_dirty_for_io(page))
-			BUG();
-		ret = afs_write_back_from_locked_page(mapping, wbc, page, end);
-		put_page(page);
-		if (ret < 0) {
-			_leave(" = %d", ret);
-			return ret;
-		}
-
-		wbc->nr_to_write -= ret;
-
-		cond_resched();
-	} while (index < end && wbc->nr_to_write > 0);
-
-	*_next = index;
-	_leave(" = 0 [%lx]", *_next);
-	return 0;
 }
 
 /*
  * write some of the pending data back to the server
  */
-int afs_writepages(struct address_space *mapping,
-		   struct writeback_control *wbc)
+int afs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 {
-	pgoff_t start, end, next;
+	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
 	int ret;
 
-	_enter("");
-
-	if (wbc->range_cyclic) {
-		start = mapping->writeback_index;
-		end = -1;
-		ret = afs_writepages_region(mapping, wbc, start, end, &next);
-		if (start > 0 && wbc->nr_to_write > 0 && ret == 0)
-			ret = afs_writepages_region(mapping, wbc, 0, start,
-						    &next);
-		mapping->writeback_index = next;
-	} else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
-		end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT);
-		ret = afs_writepages_region(mapping, wbc, 0, end, &next);
-		if (wbc->nr_to_write > 0)
-			mapping->writeback_index = next;
-	} else {
-		start = wbc->range_start >> PAGE_SHIFT;
-		end = wbc->range_end >> PAGE_SHIFT;
-		ret = afs_writepages_region(mapping, wbc, start, end, &next);
-	}
-
-	_leave(" = %d", ret);
-	return ret;
-}
-
-/*
- * completion of write to server
- */
-void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
-{
-	struct pagevec pv;
-	unsigned long priv;
-	unsigned count, loop;
-	pgoff_t first = call->first, last = call->last;
-
-	_enter("{%llx:%llu},{%lx-%lx}",
-	       vnode->fid.vid, vnode->fid.vnode, first, last);
-
-	pagevec_init(&pv);
-
-	do {
-		_debug("done %lx-%lx", first, last);
-
-		count = last - first + 1;
-		if (count > PAGEVEC_SIZE)
-			count = PAGEVEC_SIZE;
-		pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping,
-					      first, count, pv.pages);
-		ASSERTCMP(pv.nr, ==, count);
-
-		for (loop = 0; loop < count; loop++) {
-			priv = page_private(pv.pages[loop]);
-			trace_afs_page_dirty(vnode, tracepoint_string("clear"),
-					     pv.pages[loop]->index, priv);
-			set_page_private(pv.pages[loop], 0);
-			end_page_writeback(pv.pages[loop]);
-		}
-		first += count;
-		__pagevec_release(&pv);
-	} while (first <= last);
-
-	afs_prune_wb_keys(vnode);
-	_leave("");
-}
-
-/*
- * write to an AFS file
- */
-ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
-{
-	struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
-	ssize_t result;
-	size_t count = iov_iter_count(from);
-
-	_enter("{%llx:%llu},{%zu},",
-	       vnode->fid.vid, vnode->fid.vnode, count);
-
-	if (IS_SWAPFILE(&vnode->vfs_inode)) {
-		printk(KERN_INFO
-		       "AFS: Attempt to write to active swap file!\n");
-		return -EBUSY;
-	}
-
-	if (!count)
+	/* We have to be careful as we can end up racing with setattr()
+	 * truncating the pagecache since the caller doesn't take a lock here
+	 * to prevent it.
+	 */
+	if (wbc->sync_mode == WB_SYNC_ALL)
+		down_read(&vnode->validate_lock);
+	else if (!down_read_trylock(&vnode->validate_lock))
 		return 0;
 
-	result = generic_file_write_iter(iocb, from);
-
-	_leave(" = %zd", result);
-	return result;
+	ret = netfs_writepages(mapping, wbc);
+	up_read(&vnode->validate_lock);
+	return ret;
 }
 
 /*
@@ -751,13 +252,18 @@ ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
  */
 int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 {
-	struct inode *inode = file_inode(file);
-	struct afs_vnode *vnode = AFS_FS_I(inode);
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
+	struct afs_file *af = file->private_data;
+	int ret;
 
 	_enter("{%llx:%llu},{n=%pD},%d",
 	       vnode->fid.vid, vnode->fid.vnode, file,
 	       datasync);
 
+	ret = afs_validate(vnode, af->key);
+	if (ret < 0)
+		return ret;
+
 	return file_write_and_wait_range(file, start, end);
 }
 
@@ -768,44 +274,10 @@ int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
 {
 	struct file *file = vmf->vma->vm_file;
-	struct inode *inode = file_inode(file);
-	struct afs_vnode *vnode = AFS_FS_I(inode);
-	unsigned long priv;
-
-	_enter("{{%llx:%llu}},{%lx}",
-	       vnode->fid.vid, vnode->fid.vnode, vmf->page->index);
-
-	sb_start_pagefault(inode->i_sb);
-
-	/* Wait for the page to be written to the cache before we allow it to
-	 * be modified.  We then assume the entire page will need writing back.
-	 */
-#ifdef CONFIG_AFS_FSCACHE
-	fscache_wait_on_page_write(vnode->cache, vmf->page);
-#endif
-
-	if (PageWriteback(vmf->page) &&
-	    wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
-		return VM_FAULT_RETRY;
 
-	if (lock_page_killable(vmf->page) < 0)
-		return VM_FAULT_RETRY;
-
-	/* We mustn't change page->private until writeback is complete as that
-	 * details the portion of the page we need to write back and we might
-	 * need to redirty the page if there's a problem.
-	 */
-	wait_on_page_writeback(vmf->page);
-
-	priv = (unsigned long)PAGE_SIZE << AFS_PRIV_SHIFT; /* To */
-	priv |= 0; /* From */
-	trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"),
-			     vmf->page->index, priv);
-	SetPagePrivate(vmf->page);
-	set_page_private(vmf->page, priv);
-
-	sb_end_pagefault(inode->i_sb);
-	return VM_FAULT_LOCKED;
+	if (afs_validate(AFS_FS_I(file_inode(file)), afs_file_key(file)) < 0)
+		return VM_FAULT_SIGBUS;
+	return netfs_page_mkwrite(vmf, NULL);
 }
 
 /*
@@ -819,8 +291,8 @@ void afs_prune_wb_keys(struct afs_vnode *vnode)
 	/* Discard unused keys */
 	spin_lock(&vnode->wb_lock);
 
-	if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) &&
-	    !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) {
+	if (!mapping_tagged(&vnode->netfs.inode.i_data, PAGECACHE_TAG_WRITEBACK) &&
+	    !mapping_tagged(&vnode->netfs.inode.i_data, PAGECACHE_TAG_DIRTY)) {
 		list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) {
 			if (refcount_read(&wbk->usage) == 1)
 				list_move(&wbk->vnode_link, &graveyard);
@@ -835,44 +307,3 @@ void afs_prune_wb_keys(struct afs_vnode *vnode)
 		afs_put_wb_key(wbk);
 	}
 }
-
-/*
- * Clean up a page during invalidation.
- */
-int afs_launder_page(struct page *page)
-{
-	struct address_space *mapping = page->mapping;
-	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
-	unsigned long priv;
-	unsigned int f, t;
-	int ret = 0;
-
-	_enter("{%lx}", page->index);
-
-	priv = page_private(page);
-	if (clear_page_dirty_for_io(page)) {
-		f = 0;
-		t = PAGE_SIZE;
-		if (PagePrivate(page)) {
-			f = priv & AFS_PRIV_MAX;
-			t = priv >> AFS_PRIV_SHIFT;
-		}
-
-		trace_afs_page_dirty(vnode, tracepoint_string("launder"),
-				     page->index, priv);
-		ret = afs_store_data(mapping, page->index, page->index, t, f);
-	}
-
-	trace_afs_page_dirty(vnode, tracepoint_string("laundered"),
-			     page->index, priv);
-	set_page_private(page, 0);
-	ClearPagePrivate(page);
-
-#ifdef CONFIG_AFS_FSCACHE
-	if (PageFsCache(page)) {
-		fscache_wait_on_page_write(vnode->cache, page);
-		fscache_uncache_page(vnode->cache, page);
-	}
-#endif
-	return ret;
-}