1 files changed, 267 insertions, 0 deletions
diff --git a/fs/gfs2/page.c b/fs/gfs2/page.c
new file mode 100644
index 00000000000..b93caf294b9
--- /dev/null
+++ b/fs/gfs2/page.c
@@ -0,0 +1,267 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 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 <linux/gfs2_ondisk.h>
+
+#include "gfs2.h"
+#include "lm_interface.h"
+#include "incore.h"
+#include "bmap.h"
+#include "inode.h"
+#include "page.h"
+#include "trans.h"
+#include "ops_address.h"
+#include "util.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 = gl->gl_object;
+	inode = &ip->i_inode;
+	if (!ip || !S_ISREG(ip->i_di.di_mode))
+		return;
+
+	if (!test_bit(GIF_PAGED, &ip->i_flags))
+		return;
+
+	unmap_shared_mapping_range(inode->i_mapping, 0, 0);
+
+	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 = gl->gl_object;
+	inode = &ip->i_inode;
+	if (!ip || !S_ISREG(ip->i_di.di_mode))
+		return;
+
+	truncate_inode_pages(inode->i_mapping, 0);
+	gfs2_assert_withdraw(GFS2_SB(&ip->i_inode), !inode->i_mapping->nrpages);
+	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;
+	struct address_space *mapping;
+	int error = 0;
+
+	ip = gl->gl_object;
+	inode = &ip->i_inode;
+	if (!ip || !S_ISREG(ip->i_di.di_mode))
+		return;
+
+	mapping = inode->i_mapping;
+
+	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);
+
+}
+
+/**
+ * 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 = GFS2_SB(&ip->i_inode);
+	struct inode *inode = &ip->i_inode;
+	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_is_jdata(ip))
+		gfs2_trans_add_bh(ip->i_gl, bh, 0);
+	mark_buffer_dirty(bh);
+
+	if (release) {
+		unlock_page(page);
+		page_cache_release(page);
+	}
+
+	return 0;
+}
+
+/**
+ * gfs2_block_truncate_page - Deal with zeroing out data for truncate
+ *
+ * This is partly borrowed from ext3.
+ */
+int gfs2_block_truncate_page(struct address_space *mapping)
+{
+	struct inode *inode = mapping->host;
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	loff_t from = inode->i_size;
+	unsigned long index = from >> PAGE_CACHE_SHIFT;
+	unsigned offset = from & (PAGE_CACHE_SIZE-1);
+	unsigned blocksize, iblock, length, pos;
+	struct buffer_head *bh;
+	struct page *page;
+	void *kaddr;
+	int err;
+
+	page = grab_cache_page(mapping, index);
+	if (!page)
+		return 0;
+
+	blocksize = inode->i_sb->s_blocksize;
+	length = blocksize - (offset & (blocksize - 1));
+	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
+
+	if (!page_has_buffers(page))
+		create_empty_buffers(page, blocksize, 0);
+
+	/* Find the buffer that contains "offset" */
+	bh = page_buffers(page);
+	pos = blocksize;
+	while (offset >= pos) {
+		bh = bh->b_this_page;
+		iblock++;
+		pos += blocksize;
+	}
+
+	err = 0;
+
+	if (!buffer_mapped(bh)) {
+		gfs2_get_block(inode, iblock, bh, 0);
+		/* unmapped? It's a hole - nothing to do */
+		if (!buffer_mapped(bh))
+			goto unlock;
+	}
+
+	/* Ok, it's mapped. Make sure it's up-to-date */
+	if (PageUptodate(page))
+		set_buffer_uptodate(bh);
+
+	if (!buffer_uptodate(bh)) {
+		err = -EIO;
+		ll_rw_block(READ, 1, &bh);
+		wait_on_buffer(bh);
+		/* Uhhuh. Read error. Complain and punt. */
+		if (!buffer_uptodate(bh))
+			goto unlock;
+	}
+
+	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip))
+		gfs2_trans_add_bh(ip->i_gl, bh, 0);
+
+	kaddr = kmap_atomic(page, KM_USER0);
+	memset(kaddr + offset, 0, length);
+	flush_dcache_page(page);
+	kunmap_atomic(kaddr, KM_USER0);
+
+unlock:
+	unlock_page(page);
+	page_cache_release(page);
+	return err;
+}
+
+void gfs2_page_add_databufs(struct gfs2_inode *ip, 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_bh(ip->i_gl, bh, 0);
+	}
+}
+