[5/8] cifs: (untested) Move to using the alternate (deprecated) fscache I/O API

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index d0216472f1c6..865802a97ad5 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -4174,11 +4174,8 @@  static vm_fault_t
 cifs_page_mkwrite(struct vm_fault *vmf)
 {
 	struct page *page = vmf->page;
-	struct file *file = vmf->vma->vm_file;
-	struct inode *inode = file_inode(file);
-
-	cifs_fscache_wait_on_page_write(inode, page);
 
+	wait_on_page_fscache(page);
 	lock_page(page);
 	return VM_FAULT_LOCKED;
 }
@@ -4251,8 +4248,6 @@  cifs_readv_complete(struct work_struct *work)
 		if (rdata->result == 0 ||
 		    (rdata->result == -EAGAIN && got_bytes))
 			cifs_readpage_to_fscache(rdata->mapping->host, page);
-		else
-			cifs_fscache_uncache_page(rdata->mapping->host, page);
 
 		got_bytes -= min_t(unsigned int, PAGE_SIZE, got_bytes);
 
@@ -4375,6 +4370,7 @@  readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
 
 	INIT_LIST_HEAD(tmplist);
 
+again:
 	page = lru_to_page(page_list);
 
 	/*
@@ -4392,6 +4388,18 @@  readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
 		return rc;
 	}
 
+	rc = cifs_readpage_from_fscache(mapping->host, page);
+	if (rc == 0) {
+		list_del_init(&page->lru);
+		SetPageUptodate(page);
+		lru_cache_add(page);
+		unlock_page(page);
+		put_page(page);
+		if (list_empty(page_list))
+			return 0;
+		goto again;
+	}
+
 	/* move first page to the tmplist */
 	*offset = (loff_t)page->index << PAGE_SHIFT;
 	*bytes = PAGE_SIZE;
@@ -4415,10 +4423,20 @@  readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
 			__ClearPageLocked(page);
 			break;
 		}
-		list_move_tail(&page->lru, tmplist);
-		(*bytes) += PAGE_SIZE;
+
+		rc = cifs_readpage_from_fscache(mapping->host, page);
+		if (rc == 0) {
+			list_del_init(&page->lru);
+			SetPageUptodate(page);
+			lru_cache_add(page);
+			unlock_page(page);
+			put_page(page);
+		} else {
+			list_move_tail(&page->lru, tmplist);
+			(*bytes) += PAGE_SIZE;
+			(*nr_pages)++;
+		}
 		expected_index++;
-		(*nr_pages)++;
 	}
 	return rc;
 }
@@ -4436,19 +4454,6 @@  static int cifs_readpages(struct file *file, struct address_space *mapping,
 	unsigned int xid;
 
 	xid = get_xid();
-	/*
-	 * Reads as many pages as possible from fscache. Returns -ENOBUFS
-	 * immediately if the cookie is negative
-	 *
-	 * After this point, every page in the list might have PG_fscache set,
-	 * so we will need to clean that up off of every page we don't use.
-	 */
-	rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
-					 &num_pages);
-	if (rc == 0) {
-		free_xid(xid);
-		return rc;
-	}
 
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
 		pid = open_file->pid;
@@ -4573,7 +4578,6 @@  static int cifs_readpages(struct file *file, struct address_space *mapping,
 	 * the pagecache must be uncached before they get returned to the
 	 * allocator.
 	 */
-	cifs_fscache_readpages_cancel(mapping->host, page_list);
 	free_xid(xid);
 	return rc;
 }
@@ -4777,17 +4781,19 @@  static int cifs_release_page(struct page *page, gfp_t gfp)
 {
 	if (PagePrivate(page))
 		return 0;
-
-	return cifs_fscache_release_page(page, gfp);
+	if (PageFsCache(page)) {
+		if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS))
+			return false;
+		wait_on_page_fscache(page);
+	}
+	return true;
 }
 
 static void cifs_invalidate_page(struct page *page, unsigned int offset,
 				 unsigned int length)
 {
-	struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
-
 	if (offset == 0 && length == PAGE_SIZE)
-		cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
+		wait_on_page_fscache(page);
 }
 
 static int cifs_launder_page(struct page *page)
@@ -4807,7 +4813,7 @@  static int cifs_launder_page(struct page *page)
 	if (clear_page_dirty_for_io(page))
 		rc = cifs_writepage_locked(page, &wbc);
 
-	cifs_fscache_invalidate_page(page, page->mapping->host);
+	wait_on_page_fscache(page);
 	return rc;
 }
 
diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
index fab47fa7df74..d00f7ad61c5b 100644
--- a/fs/cifs/fscache.c
+++ b/fs/cifs/fscache.c
@@ -223,30 +223,6 @@  void cifs_fscache_reset_inode_cookie(struct inode *inode)
 	}
 }
 
-int cifs_fscache_release_page(struct page *page, gfp_t gfp)
-{
-	if (PageFsCache(page)) {
-		struct inode *inode = page->mapping->host;
-		struct cifsInodeInfo *cifsi = CIFS_I(inode);
-
-		cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
-			 __func__, page, cifsi->fscache);
-		if (!fscache_maybe_release_page(cifsi->fscache, page, gfp))
-			return 0;
-	}
-
-	return 1;
-}
-
-static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx,
-						int error)
-{
-	cifs_dbg(FYI, "%s: (0x%p/%d)\n", __func__, page, error);
-	if (!error)
-		SetPageUptodate(page);
-	unlock_page(page);
-}
-
 /*
  * Retrieve a page from FS-Cache
  */
@@ -256,12 +232,9 @@  int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
 
 	cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n",
 		 __func__, CIFS_I(inode)->fscache, page, inode);
-	ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page,
-					 cifs_readpage_from_fscache_complete,
-					 NULL,
-					 GFP_KERNEL);
-	switch (ret) {
 
+	ret = fscache_deprecated_read_page(cifs_inode_cookie(inode), page);
+	switch (ret) {
 	case 0: /* page found in fscache, read submitted */
 		cifs_dbg(FYI, "%s: submitted\n", __func__);
 		return ret;
@@ -276,86 +249,14 @@  int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
 	return ret;
 }
 
-/*
- * Retrieve a set of pages from FS-Cache
- */
-int __cifs_readpages_from_fscache(struct inode *inode,
-				struct address_space *mapping,
-				struct list_head *pages,
-				unsigned *nr_pages)
-{
-	int ret;
-
-	cifs_dbg(FYI, "%s: (0x%p/%u/0x%p)\n",
-		 __func__, CIFS_I(inode)->fscache, *nr_pages, inode);
-	ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping,
-					  pages, nr_pages,
-					  cifs_readpage_from_fscache_complete,
-					  NULL,
-					  mapping_gfp_mask(mapping));
-	switch (ret) {
-	case 0:	/* read submitted to the cache for all pages */
-		cifs_dbg(FYI, "%s: submitted\n", __func__);
-		return ret;
-
-	case -ENOBUFS:	/* some pages are not cached and can't be */
-	case -ENODATA:	/* some pages are not cached */
-		cifs_dbg(FYI, "%s: no page\n", __func__);
-		return 1;
-
-	default:
-		cifs_dbg(FYI, "unknown error ret = %d\n", ret);
-	}
-
-	return ret;
-}
-
 void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
 {
 	struct cifsInodeInfo *cifsi = CIFS_I(inode);
-	int ret;
 
 	WARN_ON(!cifsi->fscache);
 
 	cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
 		 __func__, cifsi->fscache, page, inode);
-	ret = fscache_write_page(cifsi->fscache, page,
-				 cifsi->vfs_inode.i_size, GFP_KERNEL);
-	if (ret != 0)
-		fscache_uncache_page(cifsi->fscache, page);
-}
-
-void __cifs_fscache_readpages_cancel(struct inode *inode, struct list_head *pages)
-{
-	cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n",
-		 __func__, CIFS_I(inode)->fscache, inode);
-	fscache_readpages_cancel(CIFS_I(inode)->fscache, pages);
-}
-
-void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
-{
-	struct cifsInodeInfo *cifsi = CIFS_I(inode);
-	struct fscache_cookie *cookie = cifsi->fscache;
-
-	cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
-	fscache_wait_on_page_write(cookie, page);
-	fscache_uncache_page(cookie, page);
-}
-
-void __cifs_fscache_wait_on_page_write(struct inode *inode, struct page *page)
-{
-	struct cifsInodeInfo *cifsi = CIFS_I(inode);
-	struct fscache_cookie *cookie = cifsi->fscache;
-
-	cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
-	fscache_wait_on_page_write(cookie, page);
-}
-
-void __cifs_fscache_uncache_page(struct inode *inode, struct page *page)
-{
-	struct cifsInodeInfo *cifsi = CIFS_I(inode);
-	struct fscache_cookie *cookie = cifsi->fscache;
 
-	cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
-	fscache_uncache_page(cookie, page);
+	fscache_deprecated_write_page(cifs_inode_cookie(inode), page);
 }
diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
index cfea3cf5d2af..fbc0b0632169 100644
--- a/fs/cifs/fscache.h
+++ b/fs/cifs/fscache.h
@@ -9,7 +9,7 @@ 
 #ifndef _CIFS_FSCACHE_H
 #define _CIFS_FSCACHE_H
 
-#define FSCACHE_USE_OLD_IO_API
+#define FSCACHE_USE_DEPRECATED_IO_API
 #include <linux/fscache.h>
 
 #include "cifsglob.h"
@@ -60,40 +60,9 @@  extern void cifs_fscache_update_inode_cookie(struct inode *inode);
 extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *);
 extern void cifs_fscache_reset_inode_cookie(struct inode *);
 
-extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);
-extern void __cifs_fscache_wait_on_page_write(struct inode *inode, struct page *page);
-extern void __cifs_fscache_uncache_page(struct inode *inode, struct page *page);
-extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);
 extern int __cifs_readpage_from_fscache(struct inode *, struct page *);
-extern int __cifs_readpages_from_fscache(struct inode *,
-					 struct address_space *,
-					 struct list_head *,
-					 unsigned *);
-extern void __cifs_fscache_readpages_cancel(struct inode *, struct list_head *);
-
 extern void __cifs_readpage_to_fscache(struct inode *, struct page *);
 
-static inline void cifs_fscache_invalidate_page(struct page *page,
-					       struct inode *inode)
-{
-	if (PageFsCache(page))
-		__cifs_fscache_invalidate_page(page, inode);
-}
-
-static inline void cifs_fscache_wait_on_page_write(struct inode *inode,
-						   struct page *page)
-{
-	if (PageFsCache(page))
-		__cifs_fscache_wait_on_page_write(inode, page);
-}
-
-static inline void cifs_fscache_uncache_page(struct inode *inode,
-						   struct page *page)
-{
-	if (PageFsCache(page))
-		__cifs_fscache_uncache_page(inode, page);
-}
-
 static inline int cifs_readpage_from_fscache(struct inode *inode,
 					     struct page *page)
 {
@@ -103,17 +72,6 @@  static inline int cifs_readpage_from_fscache(struct inode *inode,
 	return -ENOBUFS;
 }
 
-static inline int cifs_readpages_from_fscache(struct inode *inode,
-					      struct address_space *mapping,
-					      struct list_head *pages,
-					      unsigned *nr_pages)
-{
-	if (CIFS_I(inode)->fscache)
-		return __cifs_readpages_from_fscache(inode, mapping, pages,
-						     nr_pages);
-	return -ENOBUFS;
-}
-
 static inline void cifs_readpage_to_fscache(struct inode *inode,
 					    struct page *page)
 {
@@ -121,11 +79,9 @@  static inline void cifs_readpage_to_fscache(struct inode *inode,
 		__cifs_readpage_to_fscache(inode, page);
 }
 
-static inline void cifs_fscache_readpages_cancel(struct inode *inode,
-						 struct list_head *pages)
+static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
 {
-	if (CIFS_I(inode)->fscache)
-		return __cifs_fscache_readpages_cancel(inode, pages);
+	return CIFS_I(inode)->fscache;
 }
 
 #else /* CONFIG_CIFS_FSCACHE */
@@ -145,17 +101,7 @@  static inline void cifs_fscache_update_inode_cookie(struct inode *inode) {}
 static inline void cifs_fscache_set_inode_cookie(struct inode *inode,
 						 struct file *filp) {}
 static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {}
-static inline int cifs_fscache_release_page(struct page *page, gfp_t gfp)
-{
-	return 1; /* May release page */
-}
 
-static inline void cifs_fscache_invalidate_page(struct page *page,
-			struct inode *inode) {}
-static inline void cifs_fscache_wait_on_page_write(struct inode *inode,
-						   struct page *page) {}
-static inline void cifs_fscache_uncache_page(struct inode *inode,
-						   struct page *page) {}
 
 static inline int
 cifs_readpage_from_fscache(struct inode *inode, struct page *page)
@@ -163,21 +109,10 @@  cifs_readpage_from_fscache(struct inode *inode, struct page *page)
 	return -ENOBUFS;
 }
 
-static inline int cifs_readpages_from_fscache(struct inode *inode,
-					      struct address_space *mapping,
-					      struct list_head *pages,
-					      unsigned *nr_pages)
-{
-	return -ENOBUFS;
-}
-
 static inline void cifs_readpage_to_fscache(struct inode *inode,
 			struct page *page) {}
-
-static inline void cifs_fscache_readpages_cancel(struct inode *inode,
-						 struct list_head *pages)
-{
-}
+static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
+{ return NULL; }
 
 #endif /* CONFIG_CIFS_FSCACHE */