[PATCH 4/6] nfs: Teach NFS about swap cache pages

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

Teach the NFS client how to treat PG_swapcache pages.

Replace all occurences of page->index and page->mapping in the NFS client
with the new page_file_index() and page_file_mapping() functions.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 fs/nfs/dir.c      |    4 ++--
 fs/nfs/file.c     |    6 +++---
 fs/nfs/pagelist.c |    8 ++++----
 fs/nfs/read.c     |   10 +++++-----
 fs/nfs/write.c    |   34 +++++++++++++++++-----------------
 5 files changed, 31 insertions(+), 31 deletions(-)

Index: linux-2.6/fs/nfs/file.c
===================================================================
--- linux-2.6.orig/fs/nfs/file.c
+++ linux-2.6/fs/nfs/file.c
@@ -303,16 +303,16 @@ static int nfs_commit_write(struct file 
 
 static void nfs_invalidate_page(struct page *page, unsigned long offset)
 {
-	struct inode *inode = page->mapping->host;
+	struct inode *inode = page_file_mapping(page)->host;
 
 	/* Cancel any unstarted writes on this page */
 	if (offset == 0)
-		nfs_sync_inode_wait(inode, page->index, 1, FLUSH_INVALIDATE);
+		nfs_sync_inode_wait(inode, page_file_index(page), 1, FLUSH_INVALIDATE);
 }
 
 static int nfs_release_page(struct page *page, gfp_t gfp)
 {
-	return !nfs_wb_page(page->mapping->host, page);
+	return !nfs_wb_page(page_file_mapping(page)->host, page);
 }
 
 const struct address_space_operations nfs_file_aops = {
Index: linux-2.6/fs/nfs/pagelist.c
===================================================================
--- linux-2.6.orig/fs/nfs/pagelist.c
+++ linux-2.6/fs/nfs/pagelist.c
@@ -82,11 +82,11 @@ nfs_create_request(struct nfs_open_conte
 	 * update_nfs_request below if the region is not locked. */
 	req->wb_page    = page;
 	atomic_set(&req->wb_complete, 0);
-	req->wb_index	= page->index;
+	req->wb_index	= page_file_index(page);
 	page_cache_get(page);
 	BUG_ON(PagePrivate(page));
 	BUG_ON(!PageLocked(page));
-	BUG_ON(page->mapping->host != inode);
+	BUG_ON(page_file_mapping(page)->host != inode);
 	req->wb_offset  = offset;
 	req->wb_pgbase	= offset;
 	req->wb_bytes   = count;
@@ -271,7 +271,7 @@ nfs_coalesce_requests(struct list_head *
  * nfs_scan_lock_dirty - Scan the radix tree for dirty requests
  * @nfsi: NFS inode
  * @dst: Destination list
- * @idx_start: lower bound of page->index to scan
+ * @idx_start: lower bound of page_file_index(page) to scan
  * @npages: idx_start + npages sets the upper bound to scan.
  *
  * Moves elements from one of the inode request lists.
@@ -328,7 +328,7 @@ out:
  * @nfsi: NFS inode
  * @head: One of the NFS inode request lists
  * @dst: Destination list
- * @idx_start: lower bound of page->index to scan
+ * @idx_start: lower bound of page_file_index(page) to scan
  * @npages: idx_start + npages sets the upper bound to scan.
  *
  * Moves elements from one of the inode request lists.
Index: linux-2.6/fs/nfs/read.c
===================================================================
--- linux-2.6.orig/fs/nfs/read.c
+++ linux-2.6/fs/nfs/read.c
@@ -84,9 +84,9 @@ unsigned int nfs_page_length(struct inod
 	if (i_size <= 0)
 		return 0;
 	idx = (i_size - 1) >> PAGE_CACHE_SHIFT;
-	if (page->index > idx)
+	if (page_file_index(page) > idx)
 		return 0;
-	if (page->index != idx)
+	if (page_file_index(page) != idx)
 		return PAGE_CACHE_SIZE;
 	return 1 + ((i_size - 1) & (PAGE_CACHE_SIZE - 1));
 }
@@ -586,11 +586,11 @@ int nfs_readpage_result(struct rpc_task 
 int nfs_readpage(struct file *file, struct page *page)
 {
 	struct nfs_open_context *ctx;
-	struct inode *inode = page->mapping->host;
+	struct inode *inode = page_file_mapping(page)->host;
 	int		error;
 
 	dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
-		page, PAGE_CACHE_SIZE, page->index);
+		page, PAGE_CACHE_SIZE, page_file_index(page));
 	nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
 	nfs_add_stats(inode, NFSIOS_READPAGES, 1);
 
@@ -638,7 +638,7 @@ static int
 readpage_async_filler(void *data, struct page *page)
 {
 	struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
-	struct inode *inode = page->mapping->host;
+	struct inode *inode = page_file_mapping(page)->host;
 	struct nfs_page *new;
 	unsigned int len;
 
Index: linux-2.6/fs/nfs/write.c
===================================================================
--- linux-2.6.orig/fs/nfs/write.c
+++ linux-2.6/fs/nfs/write.c
@@ -152,13 +152,13 @@ void nfs_writedata_release(void *wdata)
 /* Adjust the file length if we're writing beyond the end */
 static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
 {
-	struct inode *inode = page->mapping->host;
+	struct inode *inode = page_file_mapping(page)->host;
 	loff_t end, i_size = i_size_read(inode);
 	unsigned long end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
 
-	if (i_size > 0 && page->index < end_index)
+	if (i_size > 0 && page_file_index(page) < end_index)
 		return;
-	end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count);
+	end = page_offset(page) + ((loff_t)offset+count);
 	if (i_size >= end)
 		return;
 	nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
@@ -181,11 +181,11 @@ static void nfs_mark_uptodate(struct pag
 		return;
 	}
 
-	end_offs = i_size_read(page->mapping->host) - 1;
+	end_offs = i_size_read(page_file_mapping(page)->host) - 1;
 	if (end_offs < 0)
 		return;
 	/* Is this the last page? */
-	if (page->index != (unsigned long)(end_offs >> PAGE_CACHE_SHIFT))
+	if (page_file_index(page) != (unsigned long)(end_offs >> PAGE_CACHE_SHIFT))
 		return;
 	/* This is the last page: set PG_uptodate if we cover the entire
 	 * extent of the data, then zero the rest of the page.
@@ -300,7 +300,7 @@ static int wb_priority(struct writeback_
 int nfs_writepage(struct page *page, struct writeback_control *wbc)
 {
 	struct nfs_open_context *ctx;
-	struct inode *inode = page->mapping->host;
+	struct inode *inode = page_file_mapping(page)->host;
 	unsigned long end_index;
 	unsigned offset = PAGE_CACHE_SIZE;
 	loff_t i_size = i_size_read(inode);
@@ -327,14 +327,14 @@ int nfs_writepage(struct page *page, str
 	nfs_wb_page_priority(inode, page, priority);
 
 	/* easy case */
-	if (page->index < end_index)
+	if (page_file_index(page) < end_index)
 		goto do_it;
 	/* things got complicated... */
 	offset = i_size & (PAGE_CACHE_SIZE-1);
 
 	/* OK, are we completely out? */
 	err = 0; /* potential race with truncate - ignore */
-	if (page->index >= end_index+1 || !offset)
+	if (page_file_index(page) >= end_index+1 || !offset)
 		goto out;
 do_it:
 	ctx = nfs_find_open_context(inode, NULL, FMODE_WRITE);
@@ -606,7 +606,7 @@ static void nfs_cancel_commit_list(struc
  * nfs_scan_dirty - Scan an inode for dirty requests
  * @inode: NFS inode to scan
  * @dst: destination list
- * @idx_start: lower bound of page->index to scan.
+ * @idx_start: lower bound of page_file_index(page) to scan.
  * @npages: idx_start + npages sets the upper bound to scan.
  *
  * Moves requests from the inode's dirty page list.
@@ -632,7 +632,7 @@ nfs_scan_dirty(struct inode *inode, stru
  * nfs_scan_commit - Scan an inode for commit requests
  * @inode: NFS inode to scan
  * @dst: destination list
- * @idx_start: lower bound of page->index to scan.
+ * @idx_start: lower bound of page_file_index(page) to scan.
  * @npages: idx_start + npages sets the upper bound to scan.
  *
  * Moves requests from the inode's 'commit' request list.
@@ -713,14 +713,14 @@ static struct nfs_page * nfs_update_requ
 
 	end = offset + bytes;
 
-	if (nfs_wait_on_write_congestion(page->mapping, server->flags & NFS_MOUNT_INTR))
+	if (nfs_wait_on_write_congestion(page_file_mapping(page), server->flags & NFS_MOUNT_INTR))
 		return ERR_PTR(-ERESTARTSYS);
 	for (;;) {
 		/* Loop over all inode entries and see if we find
 		 * A request for the page we wish to update
 		 */
 		spin_lock(&nfsi->req_lock);
-		req = _nfs_find_request(inode, page->index);
+		req = _nfs_find_request(inode, page_file_index(page));
 		if (req) {
 			if (!nfs_lock_request_dontget(req)) {
 				int error;
@@ -791,7 +791,7 @@ static struct nfs_page * nfs_update_requ
 int nfs_flush_incompatible(struct file *file, struct page *page)
 {
 	struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data;
-	struct inode	*inode = page->mapping->host;
+	struct inode	*inode = page_file_mapping(page)->host;
 	struct nfs_page	*req;
 	int		status = 0;
 	/*
@@ -802,7 +802,7 @@ int nfs_flush_incompatible(struct file *
 	 * Also do the same if we find a request from an existing
 	 * dropped page.
 	 */
-	req = nfs_find_request(inode, page->index);
+	req = nfs_find_request(inode, page_file_index(page));
 	if (req) {
 		if (req->wb_page != page || ctx != req->wb_context)
 			status = nfs_wb_page(inode, page);
@@ -821,7 +821,7 @@ int nfs_updatepage(struct file *file, st
 		unsigned int offset, unsigned int count)
 {
 	struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data;
-	struct inode	*inode = page->mapping->host;
+	struct inode	*inode = page_file_mapping(page)->host;
 	struct nfs_page	*req;
 	int		status = 0;
 
@@ -854,12 +854,12 @@ int nfs_updatepage(struct file *file, st
 		offset = 0;
 		if (unlikely(end_offs < 0)) {
 			/* Do nothing */
-		} else if (page->index == end_index) {
+		} else if (page_file_index(page) == end_index) {
 			unsigned int pglen;
 			pglen = (unsigned int)(end_offs & (PAGE_CACHE_SIZE-1)) + 1;
 			if (count < pglen)
 				count = pglen;
-		} else if (page->index < end_index)
+		} else if (page_file_index(page) < end_index)
 			count = PAGE_CACHE_SIZE;
 	}
 
Index: linux-2.6/fs/nfs/dir.c
===================================================================
--- linux-2.6.orig/fs/nfs/dir.c
+++ linux-2.6/fs/nfs/dir.c
@@ -177,7 +177,7 @@ int nfs_readdir_filler(nfs_readdir_descr
 
 	dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n",
 			__FUNCTION__, (long long)desc->entry->cookie,
-			page->index);
+			page_file_index(page));
 
  again:
 	timestamp = jiffies;
@@ -201,7 +201,7 @@ int nfs_readdir_filler(nfs_readdir_descr
 	 * Note: assumes we have exclusive access to this mapping either
 	 *	 through inode->i_mutex or some other mechanism.
 	 */
-	if (page->index == 0)
+	if (page_file_index(page) == 0)
 		invalidate_inode_pages2_range(inode->i_mapping, PAGE_CACHE_SIZE, -1);
 	unlock_page(page);
 	return 0;