1 files changed, 327 insertions, 413 deletions

diff --git a/fs/afs/file.c b/fs/afs/file.c
index 8415733f7bc1..d1cfb235c4b9 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -14,25 +14,30 @@
 #include <linux/gfp.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/netfs.h>
 #include "internal.h"
 
 static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
-static int afs_readpage(struct file *file, struct page *page);
-static void afs_invalidatepage(struct page *page, unsigned int offset,
-			       unsigned int length);
-static int afs_releasepage(struct page *page, gfp_t gfp_flags);
+static int afs_symlink_read_folio(struct file *file, struct folio *folio);
+static void afs_invalidate_folio(struct folio *folio, size_t offset,
+			       size_t length);
+static bool afs_release_folio(struct folio *folio, gfp_t gfp_flags);
 
-static int afs_readpages(struct file *filp, struct address_space *mapping,
-			 struct list_head *pages, unsigned nr_pages);
+static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
+static void afs_vm_open(struct vm_area_struct *area);
+static void afs_vm_close(struct vm_area_struct *area);
+static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff);
 
 const struct file_operations afs_file_operations = {
 	.open		= afs_open,
 	.release	= afs_release,
 	.llseek		= generic_file_llseek,
-	.read_iter	= generic_file_read_iter,
+	.read_iter	= afs_file_read_iter,
 	.write_iter	= afs_file_write,
 	.mmap		= afs_file_mmap,
 	.splice_read	= generic_file_splice_read,
+	.splice_write	= iter_file_splice_write,
 	.fsync		= afs_fsync,
 	.lock		= afs_lock,
 	.flock		= afs_flock,
@@ -42,25 +47,32 @@ const struct inode_operations afs_file_inode_operations = {
 	.getattr	= afs_getattr,
 	.setattr	= afs_setattr,
 	.permission	= afs_permission,
-	.listxattr	= afs_listxattr,
 };
 
-const struct address_space_operations afs_fs_aops = {
-	.readpage	= afs_readpage,
-	.readpages	= afs_readpages,
-	.set_page_dirty	= afs_set_page_dirty,
-	.launder_page	= afs_launder_page,
-	.releasepage	= afs_releasepage,
-	.invalidatepage	= afs_invalidatepage,
+const struct address_space_operations afs_file_aops = {
+	.read_folio	= netfs_read_folio,
+	.readahead	= netfs_readahead,
+	.dirty_folio	= afs_dirty_folio,
+	.launder_folio	= afs_launder_folio,
+	.release_folio	= afs_release_folio,
+	.invalidate_folio = afs_invalidate_folio,
 	.write_begin	= afs_write_begin,
 	.write_end	= afs_write_end,
 	.writepage	= afs_writepage,
 	.writepages	= afs_writepages,
 };
 
+const struct address_space_operations afs_symlink_aops = {
+	.read_folio	= afs_symlink_read_folio,
+	.release_folio	= afs_release_folio,
+	.invalidate_folio = afs_invalidate_folio,
+};
+
 static const struct vm_operations_struct afs_vm_ops = {
+	.open		= afs_vm_open,
+	.close		= afs_vm_close,
 	.fault		= filemap_fault,
-	.map_pages	= filemap_map_pages,
+	.map_pages	= afs_vm_map_pages,
 	.page_mkwrite	= afs_page_mkwrite,
 };
 
@@ -69,7 +81,7 @@ static const struct vm_operations_struct afs_vm_ops = {
  */
 void afs_put_wb_key(struct afs_wb_key *wbk)
 {
-	if (refcount_dec_and_test(&wbk->usage)) {
+	if (wbk && refcount_dec_and_test(&wbk->usage)) {
 		key_put(wbk->key);
 		kfree(wbk);
 	}
@@ -145,7 +157,9 @@ int afs_open(struct inode *inode, struct file *file)
 
 	if (file->f_flags & O_TRUNC)
 		set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
-	
+
+	fscache_use_cookie(afs_vnode_cache(vnode), file->f_mode & FMODE_WRITE);
+
 	file->private_data = af;
 	_leave(" = 0");
 	return 0;
@@ -164,8 +178,10 @@ error:
  */
 int afs_release(struct inode *inode, struct file *file)
 {
+	struct afs_vnode_cache_aux aux;
 	struct afs_vnode *vnode = AFS_FS_I(inode);
 	struct afs_file *af = file->private_data;
+	loff_t i_size;
 	int ret = 0;
 
 	_enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
@@ -176,6 +192,15 @@ int afs_release(struct inode *inode, struct file *file)
 	file->private_data = NULL;
 	if (af->wb)
 		afs_put_wb_key(af->wb);
+
+	if ((file->f_mode & FMODE_WRITE)) {
+		i_size = i_size_read(&vnode->netfs.inode);
+		afs_set_cache_aux(vnode, &aux);
+		fscache_unuse_cookie(afs_vnode_cache(vnode), &aux, &i_size);
+	} else {
+		fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
+	}
+
 	key_put(af->key);
 	kfree(af);
 	afs_prune_wb_keys(vnode);
@@ -184,418 +209,253 @@ int afs_release(struct inode *inode, struct file *file)
 }
 
 /*
+ * Allocate a new read record.
+ */
+struct afs_read *afs_alloc_read(gfp_t gfp)
+{
+	struct afs_read *req;
+
+	req = kzalloc(sizeof(struct afs_read), gfp);
+	if (req)
+		refcount_set(&req->usage, 1);
+
+	return req;
+}
+
+/*
  * Dispose of a ref to a read record.
  */
 void afs_put_read(struct afs_read *req)
 {
-	int i;
-
 	if (refcount_dec_and_test(&req->usage)) {
-		if (req->pages) {
-			for (i = 0; i < req->nr_pages; i++)
-				if (req->pages[i])
-					put_page(req->pages[i]);
-			if (req->pages != req->array)
-				kfree(req->pages);
-		}
+		if (req->cleanup)
+			req->cleanup(req);
+		key_put(req->key);
 		kfree(req);
 	}
 }
 
-#ifdef CONFIG_AFS_FSCACHE
-/*
- * deal with notification that a page was read from the cache
- */
-static void afs_file_readpage_read_complete(struct page *page,
-					    void *data,
-					    int error)
+static void afs_fetch_data_notify(struct afs_operation *op)
 {
-	_enter("%p,%p,%d", page, data, error);
+	struct afs_read *req = op->fetch.req;
+	struct netfs_io_subrequest *subreq = req->subreq;
+	int error = op->error;
+
+	if (error == -ECONNABORTED)
+		error = afs_abort_to_error(op->ac.abort_code);
+	req->error = error;
+
+	if (subreq) {
+		__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+		netfs_subreq_terminated(subreq, error ?: req->actual_len, false);
+		req->subreq = NULL;
+	} else if (req->done) {
+		req->done(req);
+	}
+}
 
-	/* if the read completes with an error, we just unlock the page and let
-	 * the VM reissue the readpage */
-	if (!error)
-		SetPageUptodate(page);
-	unlock_page(page);
+static void afs_fetch_data_success(struct afs_operation *op)
+{
+	struct afs_vnode *vnode = op->file[0].vnode;
+
+	_enter("op=%08x", op->debug_id);
+	afs_vnode_commit_status(op, &op->file[0]);
+	afs_stat_v(vnode, n_fetches);
+	atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes);
+	afs_fetch_data_notify(op);
+}
+
+static void afs_fetch_data_put(struct afs_operation *op)
+{
+	op->fetch.req->error = op->error;
+	afs_put_read(op->fetch.req);
 }
-#endif
+
+static const struct afs_operation_ops afs_fetch_data_operation = {
+	.issue_afs_rpc	= afs_fs_fetch_data,
+	.issue_yfs_rpc	= yfs_fs_fetch_data,
+	.success	= afs_fetch_data_success,
+	.aborted	= afs_check_for_remote_deletion,
+	.failed		= afs_fetch_data_notify,
+	.put		= afs_fetch_data_put,
+};
 
 /*
  * Fetch file data from the volume.
  */
-int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *req)
+int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req)
 {
-	struct afs_fs_cursor fc;
-	struct afs_status_cb *scb;
-	int ret;
+	struct afs_operation *op;
 
 	_enter("%s{%llx:%llu.%u},%x,,,",
 	       vnode->volume->name,
 	       vnode->fid.vid,
 	       vnode->fid.vnode,
 	       vnode->fid.unique,
-	       key_serial(key));
-
-	scb = kzalloc(sizeof(struct afs_status_cb), GFP_KERNEL);
-	if (!scb)
-		return -ENOMEM;
+	       key_serial(req->key));
 
-	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
-		afs_dataversion_t data_version = vnode->status.data_version;
-
-		while (afs_select_fileserver(&fc)) {
-			fc.cb_break = afs_calc_vnode_cb_break(vnode);
-			afs_fs_fetch_data(&fc, scb, req);
-		}
-
-		afs_check_for_remote_deletion(&fc, vnode);
-		afs_vnode_commit_status(&fc, vnode, fc.cb_break,
-					&data_version, scb);
-		ret = afs_end_vnode_operation(&fc);
+	op = afs_alloc_operation(req->key, vnode->volume);
+	if (IS_ERR(op)) {
+		if (req->subreq)
+			netfs_subreq_terminated(req->subreq, PTR_ERR(op), false);
+		return PTR_ERR(op);
 	}
 
-	if (ret == 0) {
-		afs_stat_v(vnode, n_fetches);
-		atomic_long_add(req->actual_len,
-				&afs_v2net(vnode)->n_fetch_bytes);
-	}
+	afs_op_set_vnode(op, 0, vnode);
 
-	kfree(scb);
-	_leave(" = %d", ret);
-	return ret;
+	op->fetch.req	= afs_get_read(req);
+	op->ops		= &afs_fetch_data_operation;
+	return afs_do_sync_operation(op);
 }
 
-/*
- * read page from file, directory or symlink, given a key to use
- */
-int afs_page_filler(void *data, struct page *page)
+static void afs_issue_read(struct netfs_io_subrequest *subreq)
 {
-	struct inode *inode = page->mapping->host;
-	struct afs_vnode *vnode = AFS_FS_I(inode);
-	struct afs_read *req;
-	struct key *key = data;
-	int ret;
-
-	_enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
-
-	BUG_ON(!PageLocked(page));
-
-	ret = -ESTALE;
-	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
-		goto error;
-
-	/* is it cached? */
-#ifdef CONFIG_AFS_FSCACHE
-	ret = fscache_read_or_alloc_page(vnode->cache,
-					 page,
-					 afs_file_readpage_read_complete,
-					 NULL,
-					 GFP_KERNEL);
-#else
-	ret = -ENOBUFS;
-#endif
-	switch (ret) {
-		/* read BIO submitted (page in cache) */
-	case 0:
-		break;
-
-		/* page not yet cached */
-	case -ENODATA:
-		_debug("cache said ENODATA");
-		goto go_on;
-
-		/* page will not be cached */
-	case -ENOBUFS:
-		_debug("cache said ENOBUFS");
-
-		/* fall through */
-	default:
-	go_on:
-		req = kzalloc(struct_size(req, array, 1), GFP_KERNEL);
-		if (!req)
-			goto enomem;
-
-		/* We request a full page.  If the page is a partial one at the
-		 * end of the file, the server will return a short read and the
-		 * unmarshalling code will clear the unfilled space.
-		 */
-		refcount_set(&req->usage, 1);
-		req->pos = (loff_t)page->index << PAGE_SHIFT;
-		req->len = PAGE_SIZE;
-		req->nr_pages = 1;
-		req->pages = req->array;
-		req->pages[0] = page;
-		get_page(page);
-
-		/* read the contents of the file from the server into the
-		 * 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;
-			}
-
-#ifdef CONFIG_AFS_FSCACHE
-			fscache_uncache_page(vnode->cache, page);
-#endif
-			BUG_ON(PageFsCache(page));
-
-			if (ret == -EINTR ||
-			    ret == -ENOMEM ||
-			    ret == -ERESTARTSYS ||
-			    ret == -EAGAIN)
-				goto error;
-			goto io_error;
-		}
+	struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
+	struct afs_read *fsreq;
+
+	fsreq = afs_alloc_read(GFP_NOFS);
+	if (!fsreq)
+		return netfs_subreq_terminated(subreq, -ENOMEM, false);
+
+	fsreq->subreq	= subreq;
+	fsreq->pos	= subreq->start + subreq->transferred;
+	fsreq->len	= subreq->len   - subreq->transferred;
+	fsreq->key	= key_get(subreq->rreq->netfs_priv);
+	fsreq->vnode	= vnode;
+	fsreq->iter	= &fsreq->def_iter;
+
+	iov_iter_xarray(&fsreq->def_iter, READ,
+			&fsreq->vnode->netfs.inode.i_mapping->i_pages,
+			fsreq->pos, fsreq->len);
+
+	afs_fetch_data(fsreq->vnode, fsreq);
+	afs_put_read(fsreq);
+}
 
-		SetPageUptodate(page);
+static int afs_symlink_read_folio(struct file *file, struct folio *folio)
+{
+	struct afs_vnode *vnode = AFS_FS_I(folio->mapping->host);
+	struct afs_read *fsreq;
+	int ret;
 
-		/* send the page to the cache */
-#ifdef CONFIG_AFS_FSCACHE
-		if (PageFsCache(page) &&
-		    fscache_write_page(vnode->cache, page, vnode->status.size,
-				       GFP_KERNEL) != 0) {
-			fscache_uncache_page(vnode->cache, page);
-			BUG_ON(PageFsCache(page));
-		}
-#endif
-		unlock_page(page);
-	}
+	fsreq = afs_alloc_read(GFP_NOFS);
+	if (!fsreq)
+		return -ENOMEM;
 
-	_leave(" = 0");
-	return 0;
+	fsreq->pos	= folio_pos(folio);
+	fsreq->len	= folio_size(folio);
+	fsreq->vnode	= vnode;
+	fsreq->iter	= &fsreq->def_iter;
+	iov_iter_xarray(&fsreq->def_iter, READ, &folio->mapping->i_pages,
+			fsreq->pos, fsreq->len);
 
-io_error:
-	SetPageError(page);
-	goto error;
-enomem:
-	ret = -ENOMEM;
-error:
-	unlock_page(page);
-	_leave(" = %d", ret);
+	ret = afs_fetch_data(fsreq->vnode, fsreq);
+	if (ret == 0)
+		folio_mark_uptodate(folio);
+	folio_unlock(folio);
 	return ret;
 }
 
-/*
- * read page from file, directory or symlink, given a file to nominate the key
- * to be used
- */
-static int afs_readpage(struct file *file, struct page *page)
+static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
 {
-	struct key *key;
-	int ret;
-
-	if (file) {
-		key = afs_file_key(file);
-		ASSERT(key != NULL);
-		ret = afs_page_filler(key, page);
-	} else {
-		struct inode *inode = page->mapping->host;
-		key = afs_request_key(AFS_FS_S(inode->i_sb)->cell);
-		if (IS_ERR(key)) {
-			ret = PTR_ERR(key);
-		} else {
-			ret = afs_page_filler(key, page);
-			key_put(key);
-		}
-	}
-	return ret;
+	rreq->netfs_priv = key_get(afs_file_key(file));
+	return 0;
 }
 
-/*
- * Make pages available as they're filled.
- */
-static void afs_readpages_page_done(struct afs_read *req)
+static int afs_begin_cache_operation(struct netfs_io_request *rreq)
 {
 #ifdef CONFIG_AFS_FSCACHE
-	struct afs_vnode *vnode = req->vnode;
-#endif
-	struct page *page = req->pages[req->index];
-
-	req->pages[req->index] = NULL;
-	SetPageUptodate(page);
+	struct afs_vnode *vnode = AFS_FS_I(rreq->inode);
 
-	/* send the page to the cache */
-#ifdef CONFIG_AFS_FSCACHE
-	if (PageFsCache(page) &&
-	    fscache_write_page(vnode->cache, page, vnode->status.size,
-			       GFP_KERNEL) != 0) {
-		fscache_uncache_page(vnode->cache, page);
-		BUG_ON(PageFsCache(page));
-	}
+	return fscache_begin_read_operation(&rreq->cache_resources,
+					    afs_vnode_cache(vnode));
+#else
+	return -ENOBUFS;
 #endif
-	unlock_page(page);
-	put_page(page);
 }
 
-/*
- * Read a contiguous set of pages.
- */
-static int afs_readpages_one(struct file *file, struct address_space *mapping,
-			     struct list_head *pages)
+static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len,
+				 struct folio **foliop, void **_fsdata)
 {
-	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
-	struct afs_read *req;
-	struct list_head *p;
-	struct page *first, *page;
-	struct key *key = afs_file_key(file);
-	pgoff_t index;
-	int ret, n, i;
-
-	/* Count the number of contiguous pages at the front of the list.  Note
-	 * that the list goes prev-wards rather than next-wards.
-	 */
-	first = lru_to_page(pages);
-	index = first->index + 1;
-	n = 1;
-	for (p = first->lru.prev; p != pages; p = p->prev) {
-		page = list_entry(p, struct page, lru);
-		if (page->index != index)
-			break;
-		index++;
-		n++;
-	}
-
-	req = kzalloc(struct_size(req, array, n), GFP_NOFS);
-	if (!req)
-		return -ENOMEM;
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
 
-	refcount_set(&req->usage, 1);
-	req->vnode = vnode;
-	req->page_done = afs_readpages_page_done;
-	req->pos = first->index;
-	req->pos <<= PAGE_SHIFT;
-	req->pages = req->array;
-
-	/* Transfer the pages to the request.  We add them in until one fails
-	 * to add to the LRU and then we stop (as that'll make a hole in the
-	 * contiguous run.
-	 *
-	 * Note that it's possible for the file size to change whilst we're
-	 * doing this, but we rely on the server returning less than we asked
-	 * for if the file shrank.  We also rely on this to deal with a partial
-	 * page at the end of the file.
-	 */
-	do {
-		page = lru_to_page(pages);
-		list_del(&page->lru);
-		index = page->index;
-		if (add_to_page_cache_lru(page, mapping, index,
-					  readahead_gfp_mask(mapping))) {
-#ifdef CONFIG_AFS_FSCACHE
-			fscache_uncache_page(vnode->cache, page);
-#endif
-			put_page(page);
-			break;
-		}
-
-		req->pages[req->nr_pages++] = page;
-		req->len += PAGE_SIZE;
-	} while (req->nr_pages < n);
+	return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0;
+}
 
-	if (req->nr_pages == 0) {
-		kfree(req);
-		return 0;
-	}
+static void afs_free_request(struct netfs_io_request *rreq)
+{
+	key_put(rreq->netfs_priv);
+}
 
-	ret = afs_fetch_data(vnode, key, req);
-	if (ret < 0)
-		goto error;
+const struct netfs_request_ops afs_req_ops = {
+	.init_request		= afs_init_request,
+	.free_request		= afs_free_request,
+	.begin_cache_operation	= afs_begin_cache_operation,
+	.check_write_begin	= afs_check_write_begin,
+	.issue_read		= afs_issue_read,
+};
 
-	task_io_account_read(PAGE_SIZE * req->nr_pages);
-	afs_put_read(req);
+int afs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	fscache_unpin_writeback(wbc, afs_vnode_cache(AFS_FS_I(inode)));
 	return 0;
-
-error:
-	if (ret == -ENOENT) {
-		_debug("got NOENT from server"
-		       " - marking file deleted and stale");
-		set_bit(AFS_VNODE_DELETED, &vnode->flags);
-		ret = -ESTALE;
-	}
-
-	for (i = 0; i < req->nr_pages; i++) {
-		page = req->pages[i];
-		if (page) {
-#ifdef CONFIG_AFS_FSCACHE
-			fscache_uncache_page(vnode->cache, page);
-#endif
-			SetPageError(page);
-			unlock_page(page);
-		}
-	}
-
-	afs_put_read(req);
-	return ret;
 }
 
 /*
- * read a set of pages
+ * Adjust the dirty region of the page on truncation or full invalidation,
+ * getting rid of the markers altogether if the region is entirely invalidated.
  */
-static int afs_readpages(struct file *file, struct address_space *mapping,
-			 struct list_head *pages, unsigned nr_pages)
+static void afs_invalidate_dirty(struct folio *folio, size_t offset,
+				 size_t length)
 {
-	struct key *key = afs_file_key(file);
-	struct afs_vnode *vnode;
-	int ret = 0;
-
-	_enter("{%d},{%lu},,%d",
-	       key_serial(key), mapping->host->i_ino, nr_pages);
-
-	ASSERT(key != NULL);
-
-	vnode = AFS_FS_I(mapping->host);
-	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
-		_leave(" = -ESTALE");
-		return -ESTALE;
-	}
-
-	/* attempt to read as many of the pages as possible */
-#ifdef CONFIG_AFS_FSCACHE
-	ret = fscache_read_or_alloc_pages(vnode->cache,
-					  mapping,
-					  pages,
-					  &nr_pages,
-					  afs_file_readpage_read_complete,
-					  NULL,
-					  mapping_gfp_mask(mapping));
-#else
-	ret = -ENOBUFS;
-#endif
-
-	switch (ret) {
-		/* all pages are being read from the cache */
-	case 0:
-		BUG_ON(!list_empty(pages));
-		BUG_ON(nr_pages != 0);
-		_leave(" = 0 [reading all]");
-		return 0;
-
-		/* there were pages that couldn't be read from the cache */
-	case -ENODATA:
-	case -ENOBUFS:
-		break;
-
-		/* other error */
-	default:
-		_leave(" = %d", ret);
-		return ret;
-	}
+	struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
+	unsigned long priv;
+	unsigned int f, t, end = offset + length;
 
-	while (!list_empty(pages)) {
-		ret = afs_readpages_one(file, mapping, pages);
-		if (ret < 0)
-			break;
-	}
+	priv = (unsigned long)folio_get_private(folio);
 
-	_leave(" = %d [netting]", ret);
-	return ret;
+	/* we clean up only if the entire page is being invalidated */
+	if (offset == 0 && length == folio_size(folio))
+		goto full_invalidate;
+
+	 /* If the page was dirtied by page_mkwrite(), the PTE stays writable
+	  * and we don't get another notification to tell us to expand it
+	  * again.
+	  */
+	if (afs_is_folio_dirty_mmapped(priv))
+		return;
+
+	/* We may need to shorten the dirty region */
+	f = afs_folio_dirty_from(folio, priv);
+	t = afs_folio_dirty_to(folio, priv);
+
+	if (t <= offset || f >= end)
+		return; /* Doesn't overlap */
+
+	if (f < offset && t > end)
+		return; /* Splits the dirty region - just absorb it */
+
+	if (f >= offset && t <= end)
+		goto undirty;
+
+	if (f < offset)
+		t = offset;
+	else
+		f = end;
+	if (f == t)
+		goto undirty;
+
+	priv = afs_folio_dirty(folio, f, t);
+	folio_change_private(folio, (void *)priv);
+	trace_afs_folio_dirty(vnode, tracepoint_string("trunc"), folio);
+	return;
+
+undirty:
+	trace_afs_folio_dirty(vnode, tracepoint_string("undirty"), folio);
+	folio_clear_dirty_for_io(folio);
+full_invalidate:
+	trace_afs_folio_dirty(vnode, tracepoint_string("inval"), folio);
+	folio_detach_private(folio);
 }
 
 /*
@@ -603,35 +463,17 @@ static int afs_readpages(struct file *file, struct address_space *mapping,
  * - release a page and clean up its private data if offset is 0 (indicating
  *   the entire page)
  */
-static void afs_invalidatepage(struct page *page, unsigned int offset,
-			       unsigned int length)
+static void afs_invalidate_folio(struct folio *folio, size_t offset,
+			       size_t length)
 {
-	struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
-	unsigned long priv;
-
-	_enter("{%lu},%u,%u", page->index, offset, length);
-
-	BUG_ON(!PageLocked(page));
+	_enter("{%lu},%zu,%zu", folio->index, offset, length);
 
-	/* we clean up only if the entire page is being invalidated */
-	if (offset == 0 && length == PAGE_SIZE) {
-#ifdef CONFIG_AFS_FSCACHE
-		if (PageFsCache(page)) {
-			struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
-			fscache_wait_on_page_write(vnode->cache, page);
-			fscache_uncache_page(vnode->cache, page);
-		}
-#endif
+	BUG_ON(!folio_test_locked(folio));
 
-		if (PagePrivate(page)) {
-			priv = page_private(page);
-			trace_afs_page_dirty(vnode, tracepoint_string("inval"),
-					     page->index, priv);
-			set_page_private(page, 0);
-			ClearPagePrivate(page);
-		}
-	}
+	if (folio_get_private(folio))
+		afs_invalidate_dirty(folio, offset, length);
 
+	folio_wait_fscache(folio);
 	_leave("");
 }
 
@@ -639,35 +481,60 @@ static void afs_invalidatepage(struct page *page, unsigned int offset,
  * release a page and clean up its private state if it's not busy
  * - return true if the page can now be released, false if not
  */
-static int afs_releasepage(struct page *page, gfp_t gfp_flags)
+static bool afs_release_folio(struct folio *folio, gfp_t gfp)
 {
-	struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
-	unsigned long priv;
+	struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
 
 	_enter("{{%llx:%llu}[%lu],%lx},%x",
-	       vnode->fid.vid, vnode->fid.vnode, page->index, page->flags,
-	       gfp_flags);
+	       vnode->fid.vid, vnode->fid.vnode, folio_index(folio), folio->flags,
+	       gfp);
 
-	/* deny if page is being written to the cache and the caller hasn't
+	/* deny if folio is being written to the cache and the caller hasn't
 	 * elected to wait */
 #ifdef CONFIG_AFS_FSCACHE
-	if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) {
-		_leave(" = F [cache busy]");
-		return 0;
+	if (folio_test_fscache(folio)) {
+		if (current_is_kswapd() || !(gfp & __GFP_FS))
+			return false;
+		folio_wait_fscache(folio);
 	}
+	fscache_note_page_release(afs_vnode_cache(vnode));
 #endif
 
-	if (PagePrivate(page)) {
-		priv = page_private(page);
-		trace_afs_page_dirty(vnode, tracepoint_string("rel"),
-				     page->index, priv);
-		set_page_private(page, 0);
-		ClearPagePrivate(page);
+	if (folio_test_private(folio)) {
+		trace_afs_folio_dirty(vnode, tracepoint_string("rel"), folio);
+		folio_detach_private(folio);
 	}
 
-	/* indicate that the page can be released */
+	/* Indicate that the folio can be released */
 	_leave(" = T");
-	return 1;
+	return true;
+}
+
+static void afs_add_open_mmap(struct afs_vnode *vnode)
+{
+	if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) {
+		down_write(&vnode->volume->cell->fs_open_mmaps_lock);
+
+		if (list_empty(&vnode->cb_mmap_link))
+			list_add_tail(&vnode->cb_mmap_link,
+				      &vnode->volume->cell->fs_open_mmaps);
+
+		up_write(&vnode->volume->cell->fs_open_mmaps_lock);
+	}
+}
+
+static void afs_drop_open_mmap(struct afs_vnode *vnode)
+{
+	if (!atomic_dec_and_test(&vnode->cb_nr_mmap))
+		return;
+
+	down_write(&vnode->volume->cell->fs_open_mmaps_lock);
+
+	if (atomic_read(&vnode->cb_nr_mmap) == 0)
+		list_del_init(&vnode->cb_mmap_link);
+
+	up_write(&vnode->volume->cell->fs_open_mmaps_lock);
+	flush_work(&vnode->cb_work);
 }
 
 /*
@@ -675,10 +542,57 @@ static int afs_releasepage(struct page *page, gfp_t gfp_flags)
  */
 static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
 	int ret;
 
+	afs_add_open_mmap(vnode);
+
 	ret = generic_file_mmap(file, vma);
 	if (ret == 0)
 		vma->vm_ops = &afs_vm_ops;
+	else
+		afs_drop_open_mmap(vnode);
 	return ret;
 }
+
+static void afs_vm_open(struct vm_area_struct *vma)
+{
+	afs_add_open_mmap(AFS_FS_I(file_inode(vma->vm_file)));
+}
+
+static void afs_vm_close(struct vm_area_struct *vma)
+{
+	afs_drop_open_mmap(AFS_FS_I(file_inode(vma->vm_file)));
+}
+
+static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff)
+{
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(vmf->vma->vm_file));
+	struct afs_file *af = vmf->vma->vm_file->private_data;
+
+	switch (afs_validate(vnode, af->key)) {
+	case 0:
+		return filemap_map_pages(vmf, start_pgoff, end_pgoff);
+	case -ENOMEM:
+		return VM_FAULT_OOM;
+	case -EINTR:
+	case -ERESTARTSYS:
+		return VM_FAULT_RETRY;
+	case -ESTALE:
+	default:
+		return VM_FAULT_SIGBUS;
+	}
+}
+
+static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
+	struct afs_file *af = iocb->ki_filp->private_data;
+	int ret;
+
+	ret = afs_validate(vnode, af->key);
+	if (ret < 0)
+		return ret;
+
+	return generic_file_read_iter(iocb, iter);
+}