/*
* 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 <asm/semaphore.h>
#include <asm/uaccess.h>
#include "gfs2.h"
#include "bmap.h"
#include "inode.h"
#include "jdata.h"
#include "meta_io.h"
#include "trans.h"
int gfs2_jdata_get_buffer(struct gfs2_inode *ip, uint64_t block, int new,
struct buffer_head **bhp)
{
struct buffer_head *bh;
int error = 0;
if (new) {
bh = gfs2_meta_new(ip->i_gl, block);
gfs2_trans_add_bh(ip->i_gl, bh, 1);
gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
} else {
error = gfs2_meta_read(ip->i_gl, block,
DIO_START | DIO_WAIT, &bh);
if (error)
return error;
if (gfs2_metatype_check(ip->i_sbd, bh, GFS2_METATYPE_JD)) {
brelse(bh);
return -EIO;
}
}
*bhp = bh;
return 0;
}
/**
* gfs2_copy2mem - Trivial copy function for gfs2_jdata_read()
* @bh: The buffer to copy from, or NULL meaning zero the buffer
* @buf: The buffer to copy/zero
* @offset: The offset in the buffer to copy from
* @size: The amount of data to copy/zero
*
* Returns: errno
*/
int gfs2_copy2mem(struct buffer_head *bh, char **buf, unsigned int offset,
unsigned int size)
{
if (bh)
memcpy(*buf, bh->b_data + offset, size);
else
memset(*buf, 0, size);
*buf += size;
return 0;
}
/**
* gfs2_copy2user - Copy bytes to user space for gfs2_jdata_read()
* @bh: The buffer
* @buf: The destination of the data
* @offset: The offset into the buffer
* @size: The amount of data to copy
*
* Returns: errno
*/
int gfs2_copy2user(struct buffer_head *bh, char **buf, unsigned int offset,
unsigned int size)
{
int error;
if (bh)
error = copy_to_user(*buf, bh->b_data + offset, size);
else
error = clear_user(*buf, size);
if (error)
error = -EFAULT;
else
*buf += size;
return error;
}
static int jdata_read_stuffed(struct gfs2_inode *ip, char *buf,
unsigned int offset, unsigned int size,
read_copy_fn_t copy_fn)
{
struct buffer_head *dibh;
int error;
error = gfs2_meta_inode_buffer(ip, &dibh);
if (!error) {
error = copy_fn(dibh, &buf,
offset + sizeof(struct gfs2_dinode), size);
brelse(dibh);
}
return (error) ? error : size;
}
/**
* gfs2_jdata_read - Read a jdata file
* @ip: The GFS2 Inode
* @buf: The buffer to place result into
* @offset: File offset to begin jdata_readng from
* @size: Amount of data to transfer
* @copy_fn: Function to actually perform the copy
*
* The @copy_fn only copies a maximum of a single block at once so
* we are safe calling it with int arguments. It is done so that
* we don't needlessly put 64bit arguments on the stack and it
* also makes the code in the @copy_fn nicer too.
*
* Returns: The amount of data actually copied or the error
*/
int gfs2_jdata_read(struct gfs2_inode *ip, char __user *buf, uint64_t offset,
unsigned int size, read_copy_fn_t copy_fn)
{
struct gfs2_sbd *sdp = ip->i_sbd;
uint64_t lblock, dblock;
uint32_t extlen = 0;
unsigned int o;
int copied = 0;
int error = 0;
if (offset >= ip->i_di.di_size)
return 0;
if ((offset + size) > ip->i_di.di_size)
size = ip->i_di.di_size - offset;
if (!size)
return 0;
if (gfs2_is_stuffed(ip))
return jdata_read_stuffed(ip, buf, (unsigned int)offset, size,
copy_fn);
if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
return -EINVAL;
lblock = offset;
o = do_div(lblock, sdp->sd_jbsize) +
sizeof(struct gfs2_meta_header);
while (copied < size) {
unsigned int amount;
struct buffer_head *bh;
int new;
amount = size - copied;
if (amount > sdp->sd_sb.sb_bsize - o)
amount = sdp->sd_sb.sb_bsize - o;
if (!extlen) {
new = 0;
error = gfs2_block_map(ip, lblock, &new,
&dblock, &extlen);
if (error)
goto fail;
}
if (extlen > 1)
gfs2_meta_ra(ip->i_gl, dblock, extlen);
if (dblock) {
error = gfs2_jdata_get_buffer(ip, dblock, new, &bh);
if (error)
goto fail;
dblock++;
extlen--;
} else
bh = NULL;
error = copy_fn(bh, &buf, o, amount);
brelse(bh);
if (error)
goto fail;
copied += amount;
lblock++;
o = sizeof(struct gfs2_meta_header);
}
return copied;
fail:
return (copied) ? copied : error;
}
/**
* gfs2_copy_from_mem - Trivial copy function for gfs2_jdata_write()
* @bh: The buffer to copy to or clear
* @buf: The buffer to copy from
* @offset: The offset in the buffer to write to
* @size: The amount of data to write
*
* Returns: errno
*/
int gfs2_copy_from_mem(struct gfs2_inode *ip, struct buffer_head *bh,
const char **buf, unsigned int offset, unsigned int size)
{
gfs2_trans_add_bh(ip->i_gl, bh, 1);
memcpy(bh->b_data + offset, *buf, size);
*buf += size;
return 0;
}
/**
* gfs2_copy_from_user - Copy bytes from user space for gfs2_jdata_write()
* @bh: The buffer to copy to or clear
* @buf: The buffer to copy from
* @offset: The offset in the buffer to write to
* @size: The amount of data to write
*
* Returns: errno
*/
int gfs2_copy_from_user(struct gfs2_inode *ip, struct buffer_head *bh,
const char __user **buf, unsigned int offset, unsigned int size)
{
int error = 0;
gfs2_trans_add_bh(ip->i_gl, bh, 1);
if (copy_from_user(bh->b_data + offset, *buf, size))
error = -EFAULT;
else
*buf += size;
return error;
}
static int jdata_write_stuffed(struct gfs2_inode *ip, char *buf,
unsigned int offset, unsigned int size,
write_copy_fn_t copy_fn)
{
struct buffer_head *dibh;
int error;
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
return error;
error = copy_fn(ip,
dibh, &buf,
offset + sizeof(struct gfs2_dinode), size);
if (!error) {
if (ip->i_di.di_size < offset + size)
ip->i_di.di_size = offset + size;
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
gfs2_dinode_out(&ip->i_di, dibh->b_data);
}
brelse(dibh);
return (error) ? error : size;
}
/**
* gfs2_jdata_write - Write bytes to a file
* @ip: The GFS2 inode
* @buf: The buffer containing information to be written
* @offset: The file offset to start writing at
* @size: The amount of data to write
* @copy_fn: Function to do the actual copying
*
* Returns: The number of bytes correctly written or error code
*/
int gfs2_jdata_write(struct gfs2_inode *ip, const char __user *buf, uint64_t offset,
unsigned int size, write_copy_fn_t copy_fn)
{
struct gfs2_sbd *sdp = ip->i_sbd;
struct buffer_head *dibh;
uint64_t lblock, dblock;
uint32_t extlen = 0;
unsigned int o;
int copied = 0;
int error = 0;
if (!size)
return 0;
if (gfs2_is_stuffed(ip) &&
offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
return jdata_write_stuffed(ip, buf, (unsigned int)offset, size,
copy_fn);
if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
return -EINVAL;
if (gfs2_is_stuffed(ip)) {
error = gfs2_unstuff_dinode(ip, NULL, NULL);
if (error)
return error;
}
lblock = offset;
o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
while (copied < size) {
unsigned int amount;
struct buffer_head *bh;
int new;
amount = size - copied;
if (amount > sdp->sd_sb.sb_bsize - o)
amount = sdp->sd_sb.sb_bsize - o;
if (!extlen) {
new = 1;
error = gfs2_block_map(ip, lblock, &new,
&dblock, &extlen);
if (error)
goto fail;
error = -EIO;
if (gfs2_assert_withdraw(sdp, dblock))
goto fail;
}
error = gfs2_jdata_get_buffer(ip, dblock,
(amount == sdp->sd_jbsize) ? 1 : new,
&bh);
if (error)
goto fail;
error = copy_fn(ip, bh, &buf, o, amount);
brelse(bh);
if (error)
goto fail;
copied += amount;
lblock++;
dblock++;
extlen--;
o = sizeof(struct gfs2_meta_header);
}
out:
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
return error;
if (ip->i_di.di_size < offset + copied)
ip->i_di.di_size = offset + copied;
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_dinode_out(&ip->i_di, dibh->b_data);
brelse(dibh);
return copied;
fail:
if (copied)
goto out;
return error;
}
