[linux.git] / fs / hpfs / buffer.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hpfs/buffer.c
 *
 *  Mikulas Patocka ([email protected]), 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]);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/hpfs/buffer.c
	4	*
	5	* Mikulas Patocka ([email protected]), 1998-1999
	6	*
	7	* general buffer i/o
	8	*/
e8edc6e0	9	#include <linux/sched.h>
5a0e3ad6	10	#include <linux/slab.h>
275f495d	11	#include <linux/blkdev.h>
1da177e4 LT	12	#include "hpfs_fn.h"
1da177e4 LT	13
a64eefaa MP	14	secno hpfs_search_hotfix_map(struct super_block *s, secno sec)
	15	{
	16	unsigned i;
	17	struct hpfs_sb_info *sbi = hpfs_sb(s);
	18	for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
	19	if (sbi->hotfix_from[i] == sec) {
	20	return sbi->hotfix_to[i];
	21	}
	22	}
	23	return sec;
	24	}
	25
	26	unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n)
	27	{
	28	unsigned i;
	29	struct hpfs_sb_info *sbi = hpfs_sb(s);
	30	for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
	31	if (sbi->hotfix_from[i] >= sec && sbi->hotfix_from[i] < sec + n) {
	32	n = sbi->hotfix_from[i] - sec;
	33	}
	34	}
	35	return n;
	36	}
	37
275f495d MP	38	void hpfs_prefetch_sectors(struct super_block *s, unsigned secno, int n)
	39	{
	40	struct buffer_head *bh;
	41	struct blk_plug plug;
	42
	43	if (n <= 0 \|\| unlikely(secno >= hpfs_sb(s)->sb_fs_size))
	44	return;
	45
a64eefaa MP	46	if (unlikely(hpfs_search_hotfix_map_for_range(s, secno, n) != n))
	47	return;
	48
275f495d MP	49	bh = sb_find_get_block(s, secno);
	50	if (bh) {
	51	if (buffer_uptodate(bh)) {
	52	brelse(bh);
	53	return;
	54	}
	55	brelse(bh);
9fa88c5d	56	}
275f495d MP	57
	58	blk_start_plug(&plug);
	59	while (n > 0) {
	60	if (unlikely(secno >= hpfs_sb(s)->sb_fs_size))
	61	break;
	62	sb_breadahead(s, secno);
	63	secno++;
	64	n--;
	65	}
	66	blk_finish_plug(&plug);
	67	}
	68
1da177e4 LT	69	/* Map a sector into a buffer and return pointers to it and to the buffer. */
	70
	71	void hpfs_map_sector(struct super_block s, unsigned secno, struct buffer_head **bhp,
	72	int ahead)
	73	{
	74	struct buffer_head *bh;
	75
7dd29d8d MP	76	hpfs_lock_assert(s);
7dd29d8d MP	77
275f495d MP	78	hpfs_prefetch_sectors(s, secno, ahead);
275f495d MP	79
1da177e4 LT	80	cond_resched();
1da177e4 LT	81
a64eefaa	82	*bhp = bh = sb_bread(s, hpfs_search_hotfix_map(s, secno));
1da177e4 LT	83	if (bh != NULL)
	84	return bh->b_data;
	85	else {
a19189e5	86	pr_err("%s(): read error\n", __func__);
1da177e4 LT	87	return NULL;
	88	}
	89	}
	90
	91	/* Like hpfs_map_sector but don't read anything */
	92
	93	void hpfs_get_sector(struct super_block s, unsigned secno, struct buffer_head **bhp)
	94	{
	95	struct buffer_head *bh;
	96	/return hpfs_map_sector(s, secno, bhp, 0);/
	97
7dd29d8d MP	98	hpfs_lock_assert(s);
7dd29d8d MP	99
1da177e4 LT	100	cond_resched();
1da177e4 LT	101
a64eefaa	102	if ((*bhp = bh = sb_getblk(s, hpfs_search_hotfix_map(s, secno))) != NULL) {
1da177e4 LT	103	if (!buffer_uptodate(bh)) wait_on_buffer(bh);
	104	set_buffer_uptodate(bh);
	105	return bh->b_data;
	106	} else {
a19189e5	107	pr_err("%s(): getblk failed\n", __func__);
1da177e4 LT	108	return NULL;
	109	}
	110	}
	111
	112	/* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */
	113
	114	void hpfs_map_4sectors(struct super_block s, unsigned secno, struct quad_buffer_head *qbh,
	115	int ahead)
	116	{
1da177e4 LT	117	char *data;
1da177e4 LT	118
7dd29d8d MP	119	hpfs_lock_assert(s);
7dd29d8d MP	120
1da177e4 LT	121	cond_resched();
	122
	123	if (secno & 3) {
a19189e5	124	pr_err("%s(): unaligned read\n", __func__);
1da177e4 LT	125	return NULL;
	126	}
	127
275f495d MP	128	hpfs_prefetch_sectors(s, secno, 4 + ahead);
275f495d MP	129
a64eefaa MP	130	if (!hpfs_map_sector(s, secno + 0, &qbh->bh[0], 0)) goto bail0;
	131	if (!hpfs_map_sector(s, secno + 1, &qbh->bh[1], 0)) goto bail1;
	132	if (!hpfs_map_sector(s, secno + 2, &qbh->bh[2], 0)) goto bail2;
	133	if (!hpfs_map_sector(s, secno + 3, &qbh->bh[3], 0)) goto bail3;
1c0b8a7a MP	134
	135	if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
	136	likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
	137	likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
	138	return qbh->data = qbh->bh[0]->b_data;
	139	}
	140
f52720ca	141	qbh->data = data = kmalloc(2048, GFP_NOFS);
1da177e4	142	if (!data) {
a19189e5	143	pr_err("%s(): out of memory\n", __func__);
1c0b8a7a	144	goto bail4;
1da177e4 LT	145	}
1da177e4 LT	146
1c0b8a7a MP	147	memcpy(data + 0 * 512, qbh->bh[0]->b_data, 512);
	148	memcpy(data + 1 * 512, qbh->bh[1]->b_data, 512);
	149	memcpy(data + 2 * 512, qbh->bh[2]->b_data, 512);
	150	memcpy(data + 3 * 512, qbh->bh[3]->b_data, 512);
1da177e4 LT	151
	152	return data;
	153
1c0b8a7a MP	154	bail4:
1c0b8a7a MP	155	brelse(qbh->bh[3]);
1da177e4 LT	156	bail3:
	157	brelse(qbh->bh[2]);
	158	bail2:
	159	brelse(qbh->bh[1]);
	160	bail1:
	161	brelse(qbh->bh[0]);
	162	bail0:
1da177e4 LT	163	return NULL;
	164	}
	165
	166	/* Don't read sectors */
	167
	168	void hpfs_get_4sectors(struct super_block s, unsigned secno,
	169	struct quad_buffer_head *qbh)
	170	{
	171	cond_resched();
	172
7dd29d8d MP	173	hpfs_lock_assert(s);
7dd29d8d MP	174
1da177e4	175	if (secno & 3) {
a19189e5	176	pr_err("%s(): unaligned read\n", __func__);
1da177e4 LT	177	return NULL;
	178	}
	179
1c0b8a7a MP	180	if (!hpfs_get_sector(s, secno + 0, &qbh->bh[0])) goto bail0;
	181	if (!hpfs_get_sector(s, secno + 1, &qbh->bh[1])) goto bail1;
	182	if (!hpfs_get_sector(s, secno + 2, &qbh->bh[2])) goto bail2;
	183	if (!hpfs_get_sector(s, secno + 3, &qbh->bh[3])) goto bail3;
	184
	185	if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
	186	likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
	187	likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
	188	return qbh->data = qbh->bh[0]->b_data;
	189	}
	190
1da177e4	191	if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
a19189e5	192	pr_err("%s(): out of memory\n", __func__);
1c0b8a7a	193	goto bail4;
1da177e4	194	}
1da177e4 LT	195	return qbh->data;
1da177e4 LT	196
1c0b8a7a MP	197	bail4:
	198	brelse(qbh->bh[3]);
	199	bail3:
	200	brelse(qbh->bh[2]);
	201	bail2:
	202	brelse(qbh->bh[1]);
	203	bail1:
	204	brelse(qbh->bh[0]);
	205	bail0:
1da177e4 LT	206	return NULL;
	207	}
	208
	209
	210	void hpfs_brelse4(struct quad_buffer_head *qbh)
	211	{
1c0b8a7a MP	212	if (unlikely(qbh->data != qbh->bh[0]->b_data))
1c0b8a7a MP	213	kfree(qbh->data);
1da177e4	214	brelse(qbh->bh[0]);
1c0b8a7a MP	215	brelse(qbh->bh[1]);
	216	brelse(qbh->bh[2]);
	217	brelse(qbh->bh[3]);
1da177e4 LT	218	}
	219
	220	void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
	221	{
1c0b8a7a MP	222	if (unlikely(qbh->data != qbh->bh[0]->b_data)) {
	223	memcpy(qbh->bh[0]->b_data, qbh->data + 0 * 512, 512);
	224	memcpy(qbh->bh[1]->b_data, qbh->data + 1 * 512, 512);
	225	memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
	226	memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
	227	}
1da177e4 LT	228	mark_buffer_dirty(qbh->bh[0]);
	229	mark_buffer_dirty(qbh->bh[1]);
	230	mark_buffer_dirty(qbh->bh[2]);
	231	mark_buffer_dirty(qbh->bh[3]);
	232	}