buffer.c
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/*
* linux/fs/hpfs/buffer.c
*
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
*
* general buffer i/o
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include "hpfs_fn.h"
/* Map a sector into a buffer and return pointers to it and to the buffer. */
void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
int ahead)
{
struct buffer_head *bh;
hpfs_lock_assert(s);
cond_resched();
*bhp = bh = sb_bread(s, secno);
if (bh != NULL)
return bh->b_data;
else {
printk("HPFS: hpfs_map_sector: read error\n");
return NULL;
}
}
/* Like hpfs_map_sector but don't read anything */
void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp)
{
struct buffer_head *bh;
/*return hpfs_map_sector(s, secno, bhp, 0);*/
hpfs_lock_assert(s);
cond_resched();
if ((*bhp = bh = sb_getblk(s, secno)) != NULL) {
if (!buffer_uptodate(bh)) wait_on_buffer(bh);
set_buffer_uptodate(bh);
return bh->b_data;
} else {
printk("HPFS: hpfs_get_sector: getblk failed\n");
return NULL;
}
}
/* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */
void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
int ahead)
{
struct buffer_head *bh;
char *data;
hpfs_lock_assert(s);
cond_resched();
if (secno & 3) {
printk("HPFS: hpfs_map_4sectors: unaligned read\n");
return NULL;
}
qbh->data = data = kmalloc(2048, GFP_NOFS);
if (!data) {
printk("HPFS: hpfs_map_4sectors: out of memory\n");
goto bail;
}
qbh->bh[0] = bh = sb_bread(s, secno);
if (!bh)
goto bail0;
memcpy(data, bh->b_data, 512);
qbh->bh[1] = bh = sb_bread(s, secno + 1);
if (!bh)
goto bail1;
memcpy(data + 512, bh->b_data, 512);
qbh->bh[2] = bh = sb_bread(s, secno + 2);
if (!bh)
goto bail2;
memcpy(data + 2 * 512, bh->b_data, 512);
qbh->bh[3] = bh = sb_bread(s, secno + 3);
if (!bh)
goto bail3;
memcpy(data + 3 * 512, bh->b_data, 512);
return data;
bail3:
brelse(qbh->bh[2]);
bail2:
brelse(qbh->bh[1]);
bail1:
brelse(qbh->bh[0]);
bail0:
kfree(data);
printk("HPFS: hpfs_map_4sectors: read error\n");
bail:
return NULL;
}
/* Don't read sectors */
void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
struct quad_buffer_head *qbh)
{
cond_resched();
hpfs_lock_assert(s);
if (secno & 3) {
printk("HPFS: hpfs_get_4sectors: unaligned read\n");
return NULL;
}
/*return hpfs_map_4sectors(s, secno, qbh, 0);*/
if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
printk("HPFS: hpfs_get_4sectors: out of memory\n");
return NULL;
}
if (!(hpfs_get_sector(s, secno, &qbh->bh[0]))) goto bail0;
if (!(hpfs_get_sector(s, secno + 1, &qbh->bh[1]))) goto bail1;
if (!(hpfs_get_sector(s, secno + 2, &qbh->bh[2]))) goto bail2;
if (!(hpfs_get_sector(s, secno + 3, &qbh->bh[3]))) goto bail3;
memcpy(qbh->data, qbh->bh[0]->b_data, 512);
memcpy(qbh->data + 512, qbh->bh[1]->b_data, 512);
memcpy(qbh->data + 2*512, qbh->bh[2]->b_data, 512);
memcpy(qbh->data + 3*512, qbh->bh[3]->b_data, 512);
return qbh->data;
bail3: brelse(qbh->bh[2]);
bail2: brelse(qbh->bh[1]);
bail1: brelse(qbh->bh[0]);
bail0:
return NULL;
}
void hpfs_brelse4(struct quad_buffer_head *qbh)
{
brelse(qbh->bh[3]);
brelse(qbh->bh[2]);
brelse(qbh->bh[1]);
brelse(qbh->bh[0]);
kfree(qbh->data);
}
void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
{
PRINTK(("hpfs_mark_4buffers_dirty\n"));
memcpy(qbh->bh[0]->b_data, qbh->data, 512);
memcpy(qbh->bh[1]->b_data, qbh->data + 512, 512);
memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
mark_buffer_dirty(qbh->bh[0]);
mark_buffer_dirty(qbh->bh[1]);
mark_buffer_dirty(qbh->bh[2]);
mark_buffer_dirty(qbh->bh[3]);
}