233 lines
5.3 KiB
C
233 lines
5.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* 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 <linux/blkdev.h>
|
|
#include "hpfs_fn.h"
|
|
|
|
secno hpfs_search_hotfix_map(struct super_block *s, secno sec)
|
|
{
|
|
unsigned i;
|
|
struct hpfs_sb_info *sbi = hpfs_sb(s);
|
|
for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
|
|
if (sbi->hotfix_from[i] == sec) {
|
|
return sbi->hotfix_to[i];
|
|
}
|
|
}
|
|
return sec;
|
|
}
|
|
|
|
unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n)
|
|
{
|
|
unsigned i;
|
|
struct hpfs_sb_info *sbi = hpfs_sb(s);
|
|
for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
|
|
if (sbi->hotfix_from[i] >= sec && sbi->hotfix_from[i] < sec + n) {
|
|
n = sbi->hotfix_from[i] - sec;
|
|
}
|
|
}
|
|
return n;
|
|
}
|
|
|
|
void hpfs_prefetch_sectors(struct super_block *s, unsigned secno, int n)
|
|
{
|
|
struct buffer_head *bh;
|
|
struct blk_plug plug;
|
|
|
|
if (n <= 0 || unlikely(secno >= hpfs_sb(s)->sb_fs_size))
|
|
return;
|
|
|
|
if (unlikely(hpfs_search_hotfix_map_for_range(s, secno, n) != n))
|
|
return;
|
|
|
|
bh = sb_find_get_block(s, secno);
|
|
if (bh) {
|
|
if (buffer_uptodate(bh)) {
|
|
brelse(bh);
|
|
return;
|
|
}
|
|
brelse(bh);
|
|
}
|
|
|
|
blk_start_plug(&plug);
|
|
while (n > 0) {
|
|
if (unlikely(secno >= hpfs_sb(s)->sb_fs_size))
|
|
break;
|
|
sb_breadahead(s, secno);
|
|
secno++;
|
|
n--;
|
|
}
|
|
blk_finish_plug(&plug);
|
|
}
|
|
|
|
/* 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);
|
|
|
|
hpfs_prefetch_sectors(s, secno, ahead);
|
|
|
|
cond_resched();
|
|
|
|
*bhp = bh = sb_bread(s, hpfs_search_hotfix_map(s, secno));
|
|
if (bh != NULL)
|
|
return bh->b_data;
|
|
else {
|
|
pr_err("%s(): read error\n", __func__);
|
|
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, hpfs_search_hotfix_map(s, secno))) != NULL) {
|
|
if (!buffer_uptodate(bh)) wait_on_buffer(bh);
|
|
set_buffer_uptodate(bh);
|
|
return bh->b_data;
|
|
} else {
|
|
pr_err("%s(): getblk failed\n", __func__);
|
|
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)
|
|
{
|
|
char *data;
|
|
|
|
hpfs_lock_assert(s);
|
|
|
|
cond_resched();
|
|
|
|
if (secno & 3) {
|
|
pr_err("%s(): unaligned read\n", __func__);
|
|
return NULL;
|
|
}
|
|
|
|
hpfs_prefetch_sectors(s, secno, 4 + ahead);
|
|
|
|
if (!hpfs_map_sector(s, secno + 0, &qbh->bh[0], 0)) goto bail0;
|
|
if (!hpfs_map_sector(s, secno + 1, &qbh->bh[1], 0)) goto bail1;
|
|
if (!hpfs_map_sector(s, secno + 2, &qbh->bh[2], 0)) goto bail2;
|
|
if (!hpfs_map_sector(s, secno + 3, &qbh->bh[3], 0)) goto bail3;
|
|
|
|
if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
|
|
likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
|
|
likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
|
|
return qbh->data = qbh->bh[0]->b_data;
|
|
}
|
|
|
|
qbh->data = data = kmalloc(2048, GFP_NOFS);
|
|
if (!data) {
|
|
pr_err("%s(): out of memory\n", __func__);
|
|
goto bail4;
|
|
}
|
|
|
|
memcpy(data + 0 * 512, qbh->bh[0]->b_data, 512);
|
|
memcpy(data + 1 * 512, qbh->bh[1]->b_data, 512);
|
|
memcpy(data + 2 * 512, qbh->bh[2]->b_data, 512);
|
|
memcpy(data + 3 * 512, qbh->bh[3]->b_data, 512);
|
|
|
|
return data;
|
|
|
|
bail4:
|
|
brelse(qbh->bh[3]);
|
|
bail3:
|
|
brelse(qbh->bh[2]);
|
|
bail2:
|
|
brelse(qbh->bh[1]);
|
|
bail1:
|
|
brelse(qbh->bh[0]);
|
|
bail0:
|
|
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) {
|
|
pr_err("%s(): unaligned read\n", __func__);
|
|
return NULL;
|
|
}
|
|
|
|
if (!hpfs_get_sector(s, secno + 0, &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;
|
|
|
|
if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
|
|
likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
|
|
likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
|
|
return qbh->data = qbh->bh[0]->b_data;
|
|
}
|
|
|
|
if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
|
|
pr_err("%s(): out of memory\n", __func__);
|
|
goto bail4;
|
|
}
|
|
return qbh->data;
|
|
|
|
bail4:
|
|
brelse(qbh->bh[3]);
|
|
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)
|
|
{
|
|
if (unlikely(qbh->data != qbh->bh[0]->b_data))
|
|
kfree(qbh->data);
|
|
brelse(qbh->bh[0]);
|
|
brelse(qbh->bh[1]);
|
|
brelse(qbh->bh[2]);
|
|
brelse(qbh->bh[3]);
|
|
}
|
|
|
|
void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
|
|
{
|
|
if (unlikely(qbh->data != qbh->bh[0]->b_data)) {
|
|
memcpy(qbh->bh[0]->b_data, qbh->data + 0 * 512, 512);
|
|
memcpy(qbh->bh[1]->b_data, qbh->data + 1 * 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]);
|
|
}
|