1 files changed, 273 insertions, 0 deletions
diff --git a/fs/gfs2/page.c b/fs/gfs2/page.c
new file mode 100644
index 000000000000..05453c5a06f0
--- /dev/null
+++ b/fs/gfs2/page.c
@@ -0,0 +1,273 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/pagemap.h>
+#include <linux/mm.h>
+#include <asm/semaphore.h>
+
+#include "gfs2.h"
+#include "bmap.h"
+#include "inode.h"
+#include "page.h"
+#include "trans.h"
+
+/**
+ * gfs2_pte_inval - Sync and invalidate all PTEs associated with a glock
+ * @gl: the glock
+ *
+ */
+
+void gfs2_pte_inval(struct gfs2_glock *gl)
+{
+	struct gfs2_inode *ip;
+	struct inode *inode;
+
+	ip = get_gl2ip(gl);
+	if (!ip || !S_ISREG(ip->i_di.di_mode))
+		return;
+
+	if (!test_bit(GIF_PAGED, &ip->i_flags))
+		return;
+
+	inode = gfs2_ip2v_lookup(ip);
+	if (inode) {
+		unmap_shared_mapping_range(inode->i_mapping, 0, 0);
+		iput(inode);
+
+		if (test_bit(GIF_SW_PAGED, &ip->i_flags))
+			set_bit(GLF_DIRTY, &gl->gl_flags);
+	}
+
+	clear_bit(GIF_SW_PAGED, &ip->i_flags);
+}
+
+/**
+ * gfs2_page_inval - Invalidate all pages associated with a glock
+ * @gl: the glock
+ *
+ */
+
+void gfs2_page_inval(struct gfs2_glock *gl)
+{
+	struct gfs2_inode *ip;
+	struct inode *inode;
+
+	ip = get_gl2ip(gl);
+	if (!ip || !S_ISREG(ip->i_di.di_mode))
+		return;
+
+	inode = gfs2_ip2v_lookup(ip);
+	if (inode) {
+		struct address_space *mapping = inode->i_mapping;
+
+		truncate_inode_pages(mapping, 0);
+		gfs2_assert_withdraw(ip->i_sbd, !mapping->nrpages);
+
+		iput(inode);
+	}
+
+	clear_bit(GIF_PAGED, &ip->i_flags);
+}
+
+/**
+ * gfs2_page_sync - Sync the data pages (not metadata) associated with a glock
+ * @gl: the glock
+ * @flags: DIO_START | DIO_WAIT
+ *
+ * Syncs data (not metadata) for a regular file.
+ * No-op for all other types.
+ */
+
+void gfs2_page_sync(struct gfs2_glock *gl, int flags)
+{
+	struct gfs2_inode *ip;
+	struct inode *inode;
+
+	ip = get_gl2ip(gl);
+	if (!ip || !S_ISREG(ip->i_di.di_mode))
+		return;
+
+	inode = gfs2_ip2v_lookup(ip);
+	if (inode) {
+		struct address_space *mapping = inode->i_mapping;
+		int error = 0;
+
+		if (flags & DIO_START)
+			filemap_fdatawrite(mapping);
+		if (!error && (flags & DIO_WAIT))
+			error = filemap_fdatawait(mapping);
+
+		/* Put back any errors cleared by filemap_fdatawait()
+		   so they can be caught by someone who can pass them
+		   up to user space. */
+
+		if (error == -ENOSPC)
+			set_bit(AS_ENOSPC, &mapping->flags);
+		else if (error)
+			set_bit(AS_EIO, &mapping->flags);
+
+		iput(inode);
+	}
+}
+
+/**
+ * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page
+ * @ip: the inode
+ * @dibh: the dinode buffer
+ * @block: the block number that was allocated
+ * @private: any locked page held by the caller process
+ *
+ * Returns: errno
+ */
+
+int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
+			uint64_t block, void *private)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct inode *inode = ip->i_vnode;
+	struct page *page = (struct page *)private;
+	struct buffer_head *bh;
+	int release = 0;
+
+	if (!page || page->index) {
+		page = grab_cache_page(inode->i_mapping, 0);
+		if (!page)
+			return -ENOMEM;
+		release = 1;
+	}
+
+	if (!PageUptodate(page)) {
+		void *kaddr = kmap(page);
+
+		memcpy(kaddr,
+		       dibh->b_data + sizeof(struct gfs2_dinode),
+		       ip->i_di.di_size);
+		memset(kaddr + ip->i_di.di_size,
+		       0,
+		       PAGE_CACHE_SIZE - ip->i_di.di_size);
+		kunmap(page);
+
+		SetPageUptodate(page);
+	}
+
+	if (!page_has_buffers(page))
+		create_empty_buffers(page, 1 << inode->i_blkbits,
+				     (1 << BH_Uptodate));
+
+	bh = page_buffers(page);
+
+	if (!buffer_mapped(bh))
+		map_bh(bh, inode->i_sb, block);
+
+	set_buffer_uptodate(bh);
+	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED)
+		gfs2_trans_add_databuf(sdp, bh);
+	mark_buffer_dirty(bh);
+
+	if (release) {
+		unlock_page(page);
+		page_cache_release(page);
+	}
+
+	return 0;
+}
+
+/**
+ * gfs2_truncator_page - truncate a partial data block in the page cache
+ * @ip: the inode
+ * @size: the size the file should be
+ *
+ * Returns: errno
+ */
+
+int gfs2_truncator_page(struct gfs2_inode *ip, uint64_t size)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct inode *inode = ip->i_vnode;
+	struct page *page;
+	struct buffer_head *bh;
+	void *kaddr;
+	uint64_t lbn, dbn;
+	unsigned long index;
+	unsigned int offset;
+	unsigned int bufnum;
+	int new = 0;
+	int error;
+
+	lbn = size >> inode->i_blkbits;
+	error = gfs2_block_map(ip, lbn, &new, &dbn, NULL);
+	if (error || !dbn)
+		return error;
+
+	index = size >> PAGE_CACHE_SHIFT;
+	offset = size & (PAGE_CACHE_SIZE - 1);
+	bufnum = lbn - (index << (PAGE_CACHE_SHIFT - inode->i_blkbits));
+
+	page = read_cache_page(inode->i_mapping, index,
+			       (filler_t *)inode->i_mapping->a_ops->readpage,
+			       NULL);
+	if (IS_ERR(page))
+		return PTR_ERR(page);
+
+	lock_page(page);
+
+	if (!PageUptodate(page) || PageError(page)) {
+		error = -EIO;
+		goto out;
+	}
+
+	kaddr = kmap(page);
+	memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
+	kunmap(page);
+
+	if (!page_has_buffers(page))
+		create_empty_buffers(page, 1 << inode->i_blkbits,
+				     (1 << BH_Uptodate));
+
+	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
+		/* Do nothing */;
+
+	if (!buffer_mapped(bh))
+		map_bh(bh, inode->i_sb, dbn);
+
+	set_buffer_uptodate(bh);
+	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED)
+		gfs2_trans_add_databuf(sdp, bh);
+	mark_buffer_dirty(bh);
+
+ out:
+	unlock_page(page);
+	page_cache_release(page);
+
+	return error;
+}
+
+void gfs2_page_add_databufs(struct gfs2_sbd *sdp, struct page *page,
+			    unsigned int from, unsigned int to)
+{
+	struct buffer_head *head = page_buffers(page);
+	unsigned int bsize = head->b_size;
+	struct buffer_head *bh;
+	unsigned int start, end;
+
+	for (bh = head, start = 0;
+	     bh != head || !start;
+	     bh = bh->b_this_page, start = end) {
+		end = start + bsize;
+		if (end <= from || start >= to)
+			continue;
+		gfs2_trans_add_databuf(sdp, bh);
+	}
+}
+