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/******************************************************************************
*******************************************************************************
**
** 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 <stdint.h>
#include "list.h"
#include "gfs_ondisk.h"
#include "libgfs.h"
/*
* get_buf - get a buffer
* @sdp: the super block
* @blkno: blk # that this buffer will be associated with
* @bhp: the location where the buffer is returned
*
* This function allocates space for a buffer head structure
* and the corresponding data. It does not fill in the
* actual data - that is done by read_buf.
*
* Returns: 0 on success, -1 on error
*/
int get_buf(uint32_t sb_bsize, uint64 blkno, osi_buf_t **bhp)
{
osi_buf_t *bh = NULL;
*bhp = NULL;
bh = (osi_buf_t *)malloc(sizeof(osi_buf_t));
if(!bh){
log_err("Unable to allocate memory for new buffer head.\n");
return -1;
}
if(!memset(bh, 0, sizeof(osi_buf_t))) {
log_err("Unable to zero buffer head\n");
return -1;
}
/* FIXME: Not sure how this will work on all
* architectures without the casts */
bh->b_blocknr = blkno;
bh->b_size = sb_bsize;
bh->b_state = 0;
if(!(bh->b_data = malloc(BH_SIZE(bh)))) {
free(bh);
log_err("Unable to allocate memory for new buffer "
"blkno = %"PRIu64", size = %u\n", blkno, BH_SIZE(bh));
return -1;
}
if(!memset(BH_DATA(bh), 0, BH_SIZE(bh))) {
free(bh);
log_err("Unable to zero memory for new buffer "
"blkno = %"PRIu64", size = %u\n", blkno, BH_SIZE(bh));
}
*bhp = bh;
return 0;
}
/*
* relse_buf - release a buffer
* @sdp: the super block
* @bh: the buffer to release
*
* This function will release the memory of the buffer
* and associated buffer head.
*
* Returns: nothing
*/
void relse_buf(osi_buf_t *bh){
if(bh){
if(BH_DATA(bh)) {
free(BH_DATA(bh));
bh->b_data = NULL;
}
free(bh);
bh = NULL;
}
}
/*
* read_buf - read a buffer
* @sdp: the super block
* @blkno: block number
* @bhp: place where buffer is returned
* @flags:
*
* Returns 0 on success, -1 on error
*/
int read_buf(int disk_fd, osi_buf_t *bh, int flags){
if(do_lseek(disk_fd, (uint64)(BH_BLKNO(bh)*BH_SIZE(bh)))){
log_err("Unable to seek to position %"PRIu64" "
"(%"PRIu64" * %u) on storage device.\n",
(uint64)(BH_BLKNO(bh) * BH_SIZE(bh)),
BH_BLKNO(bh), BH_SIZE(bh));
return -1;
}
if(do_read(disk_fd, BH_DATA(bh), BH_SIZE(bh))){
log_err("Unable to read %u bytes from position %"PRIu64"\n",
BH_SIZE(bh), (uint64)(BH_BLKNO(bh) * BH_SIZE(bh)));
return -1;
}
return 0;
}
/*
* write_buf - write a buffer
* @sdp: the super block
* @bh: buffer head that describes buffer to write
* @flags: flags that determine usage
*
* Returns: 0 on success, -1 on failure
*/
int write_buf(int disk_fd, osi_buf_t *bh, int flags){
if(do_lseek(disk_fd, (uint64)(BH_BLKNO(bh) * BH_SIZE(bh)))) {
log_err("Unable to seek to position %"PRIu64
"(%"PRIu64" * %u) on storage device.\n",
(uint64)(BH_BLKNO(bh) * BH_SIZE(bh)),
BH_BLKNO(bh), BH_SIZE(bh));
return -1;
}
log_debug("Writing to %"PRIu64" - %"PRIu64" %u\n",
(uint64)(BH_BLKNO(bh) * BH_SIZE(bh)),
BH_BLKNO(bh), BH_SIZE(bh));
if(do_write(disk_fd, BH_DATA(bh), BH_SIZE(bh))) {
log_err("Unable to write %u bytes to position %"PRIu64"\n",
BH_SIZE(bh), (uint64)(BH_BLKNO(bh) * BH_SIZE(bh)));
return -1;
}
if(flags & BW_WAIT){
fsync(disk_fd);
}
return 0;
}
/*
* get_and_read_buf - combines get_buf and read_buf functions
* @sdp
* @blkno
* @bhp
* @flags
*
* Returns: 0 on success, -1 on error
*/
int get_and_read_buf(int disk_fd, uint32_t sb_bsize, uint64 blkno,
osi_buf_t **bhp, int flags)
{
if(get_buf(sb_bsize, blkno, bhp)) {
stack;
return -1;
}
if(read_buf(disk_fd, *bhp, flags)){
stack;
relse_buf(*bhp);
*bhp = NULL; /* guarantee that ptr is NULL in failure cases */
return -1;
}
return 0;
}

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