/*
* 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 <linux/gfs2_ondisk.h>
#include <asm/semaphore.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;
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 = gl->gl_object;
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 = gl->gl_object;
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_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 = inode->u.generic_ip;
struct gfs2_sbd *sdp = ip->i_sbd;
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);
}
}
