[mirror_ubuntu-zesty-kernel.git] / fs / ufs / cylinder.c

/*
 *  linux/fs/ufs/cylinder.c
 *
 * Copyright (C) 1998
 * Daniel Pirkl <daniel.pirkl@email.cz>
 * Charles University, Faculty of Mathematics and Physics
 *
 *  ext2 - inode (block) bitmap caching inspired
 */

#include <linux/fs.h>
#include <linux/time.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/bitops.h>

#include <asm/byteorder.h>

#include "ufs_fs.h"
#include "ufs.h"
#include "swab.h"
#include "util.h"

/*
 * Read cylinder group into cache. The memory space for ufs_cg_private_info
 * structure is already allocated during ufs_read_super.
 */
static void ufs_read_cylinder (struct super_block * sb,
	unsigned cgno, unsigned bitmap_nr)
{
	struct ufs_sb_info * sbi = UFS_SB(sb);
	struct ufs_sb_private_info * uspi;
	struct ufs_cg_private_info * ucpi;
	struct ufs_cylinder_group * ucg;
	unsigned i, j;

	UFSD("ENTER, cgno %u, bitmap_nr %u\n", cgno, bitmap_nr);
	uspi = sbi->s_uspi;
	ucpi = sbi->s_ucpi[bitmap_nr];
	ucg = (struct ufs_cylinder_group *)sbi->s_ucg[cgno]->b_data;

	UCPI_UBH(ucpi)->fragment = ufs_cgcmin(cgno);
	UCPI_UBH(ucpi)->count = uspi->s_cgsize >> sb->s_blocksize_bits;
	/*
	 * We have already the first fragment of cylinder group block in buffer
	 */
	UCPI_UBH(ucpi)->bh[0] = sbi->s_ucg[cgno];
	for (i = 1; i < UCPI_UBH(ucpi)->count; i++)
		if (!(UCPI_UBH(ucpi)->bh[i] = sb_bread(sb, UCPI_UBH(ucpi)->fragment + i)))
			goto failed;
	sbi->s_cgno[bitmap_nr] = cgno;
			
	ucpi->c_cgx	= fs32_to_cpu(sb, ucg->cg_cgx);
	ucpi->c_ncyl	= fs16_to_cpu(sb, ucg->cg_ncyl);
	ucpi->c_niblk	= fs16_to_cpu(sb, ucg->cg_niblk);
	ucpi->c_ndblk	= fs32_to_cpu(sb, ucg->cg_ndblk);
	ucpi->c_rotor	= fs32_to_cpu(sb, ucg->cg_rotor);
	ucpi->c_frotor	= fs32_to_cpu(sb, ucg->cg_frotor);
	ucpi->c_irotor	= fs32_to_cpu(sb, ucg->cg_irotor);
	ucpi->c_btotoff	= fs32_to_cpu(sb, ucg->cg_btotoff);
	ucpi->c_boff	= fs32_to_cpu(sb, ucg->cg_boff);
	ucpi->c_iusedoff = fs32_to_cpu(sb, ucg->cg_iusedoff);
	ucpi->c_freeoff	= fs32_to_cpu(sb, ucg->cg_freeoff);
	ucpi->c_nextfreeoff = fs32_to_cpu(sb, ucg->cg_nextfreeoff);
	ucpi->c_clustersumoff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clustersumoff);
	ucpi->c_clusteroff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clusteroff);
	ucpi->c_nclusterblks = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_nclusterblks);
	UFSD("EXIT\n");
	return;	
	
failed:
	for (j = 1; j < i; j++)
		brelse (sbi->s_ucg[j]);
	sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY;
	ufs_error (sb, "ufs_read_cylinder", "can't read cylinder group block %u", cgno);
}

/*
 * Remove cylinder group from cache, doesn't release memory
 * allocated for cylinder group (this is done at ufs_put_super only).
 */
void ufs_put_cylinder (struct super_block * sb, unsigned bitmap_nr)
{
	struct ufs_sb_info * sbi = UFS_SB(sb);
	struct ufs_sb_private_info * uspi; 
	struct ufs_cg_private_info * ucpi;
	struct ufs_cylinder_group * ucg;
	unsigned i;

	UFSD("ENTER, bitmap_nr %u\n", bitmap_nr);

	uspi = sbi->s_uspi;
	if (sbi->s_cgno[bitmap_nr] == UFS_CGNO_EMPTY) {
		UFSD("EXIT\n");
		return;
	}
	ucpi = sbi->s_ucpi[bitmap_nr];
	ucg = ubh_get_ucg(UCPI_UBH(ucpi));

	if (uspi->s_ncg > UFS_MAX_GROUP_LOADED && bitmap_nr >= sbi->s_cg_loaded) {
		ufs_panic (sb, "ufs_put_cylinder", "internal error");
		return;
	}
	/*
	 * rotor is not so important data, so we put it to disk 
	 * at the end of working with cylinder
	 */
	ucg->cg_rotor = cpu_to_fs32(sb, ucpi->c_rotor);
	ucg->cg_frotor = cpu_to_fs32(sb, ucpi->c_frotor);
	ucg->cg_irotor = cpu_to_fs32(sb, ucpi->c_irotor);
	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
	for (i = 1; i < UCPI_UBH(ucpi)->count; i++) {
		brelse (UCPI_UBH(ucpi)->bh[i]);
	}

	sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY;
	UFSD("EXIT\n");
}

/*
 * Find cylinder group in cache and return it as pointer.
 * If cylinder group is not in cache, we will load it from disk.
 *
 * The cache is managed by LRU algorithm. 
 */
struct ufs_cg_private_info * ufs_load_cylinder (
	struct super_block * sb, unsigned cgno)
{
	struct ufs_sb_info * sbi = UFS_SB(sb);
	struct ufs_sb_private_info * uspi;
	struct ufs_cg_private_info * ucpi;
	unsigned cg, i, j;

	UFSD("ENTER, cgno %u\n", cgno);

	uspi = sbi->s_uspi;
	if (cgno >= uspi->s_ncg) {
		ufs_panic (sb, "ufs_load_cylinder", "internal error, high number of cg");
		return NULL;
	}
	/*
	 * Cylinder group number cg it in cache and it was last used
	 */
	if (sbi->s_cgno[0] == cgno) {
		UFSD("EXIT\n");
		return sbi->s_ucpi[0];
	}
	/*
	 * Number of cylinder groups is not higher than UFS_MAX_GROUP_LOADED
	 */
	if (uspi->s_ncg <= UFS_MAX_GROUP_LOADED) {
		if (sbi->s_cgno[cgno] != UFS_CGNO_EMPTY) {
			if (sbi->s_cgno[cgno] != cgno) {
				ufs_panic (sb, "ufs_load_cylinder", "internal error, wrong number of cg in cache");
				UFSD("EXIT (FAILED)\n");
				return NULL;
			}
			else {
				UFSD("EXIT\n");
				return sbi->s_ucpi[cgno];
			}
		} else {
			ufs_read_cylinder (sb, cgno, cgno);
			UFSD("EXIT\n");
			return sbi->s_ucpi[cgno];
		}
	}
	/*
	 * Cylinder group number cg is in cache but it was not last used, 
	 * we will move to the first position
	 */
	for (i = 0; i < sbi->s_cg_loaded && sbi->s_cgno[i] != cgno; i++);
	if (i < sbi->s_cg_loaded && sbi->s_cgno[i] == cgno) {
		cg = sbi->s_cgno[i];
		ucpi = sbi->s_ucpi[i];
		for (j = i; j > 0; j--) {
			sbi->s_cgno[j] = sbi->s_cgno[j-1];
			sbi->s_ucpi[j] = sbi->s_ucpi[j-1];
		}
		sbi->s_cgno[0] = cg;
		sbi->s_ucpi[0] = ucpi;
	/*
	 * Cylinder group number cg is not in cache, we will read it from disk
	 * and put it to the first position
	 */
	} else {
		if (sbi->s_cg_loaded < UFS_MAX_GROUP_LOADED)
			sbi->s_cg_loaded++;
		else
			ufs_put_cylinder (sb, UFS_MAX_GROUP_LOADED-1);
		ucpi = sbi->s_ucpi[sbi->s_cg_loaded - 1];
		for (j = sbi->s_cg_loaded - 1; j > 0; j--) {
			sbi->s_cgno[j] = sbi->s_cgno[j-1];
			sbi->s_ucpi[j] = sbi->s_ucpi[j-1];
		}
		sbi->s_ucpi[0] = ucpi;
		ufs_read_cylinder (sb, cgno, 0);
	}
	UFSD("EXIT\n");
	return sbi->s_ucpi[0];
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/ufs/cylinder.c
	3	*
	4	* Copyright (C) 1998
	5	* Daniel Pirkl <daniel.pirkl@email.cz>
	6	* Charles University, Faculty of Mathematics and Physics
	7	*
	8	* ext2 - inode (block) bitmap caching inspired
	9	*/
	10
	11	#include <linux/fs.h>
1da177e4 LT	12	#include <linux/time.h>
	13	#include <linux/stat.h>
	14	#include <linux/string.h>
	15	#include <linux/bitops.h>
	16
	17	#include <asm/byteorder.h>
	18
e5420598	19	#include "ufs_fs.h"
bcd6d4ec	20	#include "ufs.h"
1da177e4 LT	21	#include "swab.h"
	22	#include "util.h"
	23
1da177e4 LT	24	/*
	25	* Read cylinder group into cache. The memory space for ufs_cg_private_info
	26	* structure is already allocated during ufs_read_super.
	27	*/
	28	static void ufs_read_cylinder (struct super_block * sb,
	29	unsigned cgno, unsigned bitmap_nr)
	30	{
	31	struct ufs_sb_info * sbi = UFS_SB(sb);
	32	struct ufs_sb_private_info * uspi;
	33	struct ufs_cg_private_info * ucpi;
	34	struct ufs_cylinder_group * ucg;
	35	unsigned i, j;
	36
abf5d15f	37	UFSD("ENTER, cgno %u, bitmap_nr %u\n", cgno, bitmap_nr);
1da177e4 LT	38	uspi = sbi->s_uspi;
	39	ucpi = sbi->s_ucpi[bitmap_nr];
	40	ucg = (struct ufs_cylinder_group *)sbi->s_ucg[cgno]->b_data;
	41
9695ef16 ED	42	UCPI_UBH(ucpi)->fragment = ufs_cgcmin(cgno);
9695ef16 ED	43	UCPI_UBH(ucpi)->count = uspi->s_cgsize >> sb->s_blocksize_bits;
1da177e4 LT	44	/*
	45	* We have already the first fragment of cylinder group block in buffer
	46	*/
9695ef16 ED	47	UCPI_UBH(ucpi)->bh[0] = sbi->s_ucg[cgno];
	48	for (i = 1; i < UCPI_UBH(ucpi)->count; i++)
	49	if (!(UCPI_UBH(ucpi)->bh[i] = sb_bread(sb, UCPI_UBH(ucpi)->fragment + i)))
1da177e4 LT	50	goto failed;
	51	sbi->s_cgno[bitmap_nr] = cgno;
	52
	53	ucpi->c_cgx = fs32_to_cpu(sb, ucg->cg_cgx);
	54	ucpi->c_ncyl = fs16_to_cpu(sb, ucg->cg_ncyl);
	55	ucpi->c_niblk = fs16_to_cpu(sb, ucg->cg_niblk);
	56	ucpi->c_ndblk = fs32_to_cpu(sb, ucg->cg_ndblk);
	57	ucpi->c_rotor = fs32_to_cpu(sb, ucg->cg_rotor);
	58	ucpi->c_frotor = fs32_to_cpu(sb, ucg->cg_frotor);
	59	ucpi->c_irotor = fs32_to_cpu(sb, ucg->cg_irotor);
	60	ucpi->c_btotoff = fs32_to_cpu(sb, ucg->cg_btotoff);
	61	ucpi->c_boff = fs32_to_cpu(sb, ucg->cg_boff);
	62	ucpi->c_iusedoff = fs32_to_cpu(sb, ucg->cg_iusedoff);
	63	ucpi->c_freeoff = fs32_to_cpu(sb, ucg->cg_freeoff);
	64	ucpi->c_nextfreeoff = fs32_to_cpu(sb, ucg->cg_nextfreeoff);
	65	ucpi->c_clustersumoff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clustersumoff);
	66	ucpi->c_clusteroff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clusteroff);
	67	ucpi->c_nclusterblks = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_nclusterblks);
abf5d15f	68	UFSD("EXIT\n");
1da177e4 LT	69	return;
	70
	71	failed:
	72	for (j = 1; j < i; j++)
	73	brelse (sbi->s_ucg[j]);
	74	sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY;
	75	ufs_error (sb, "ufs_read_cylinder", "can't read cylinder group block %u", cgno);
	76	}
	77
	78	/*
	79	* Remove cylinder group from cache, doesn't release memory
	80	* allocated for cylinder group (this is done at ufs_put_super only).
	81	*/
	82	void ufs_put_cylinder (struct super_block * sb, unsigned bitmap_nr)
	83	{
	84	struct ufs_sb_info * sbi = UFS_SB(sb);
	85	struct ufs_sb_private_info * uspi;
	86	struct ufs_cg_private_info * ucpi;
	87	struct ufs_cylinder_group * ucg;
	88	unsigned i;
	89
abf5d15f	90	UFSD("ENTER, bitmap_nr %u\n", bitmap_nr);
1da177e4 LT	91
	92	uspi = sbi->s_uspi;
	93	if (sbi->s_cgno[bitmap_nr] == UFS_CGNO_EMPTY) {
abf5d15f	94	UFSD("EXIT\n");
1da177e4 LT	95	return;
	96	}
	97	ucpi = sbi->s_ucpi[bitmap_nr];
9695ef16	98	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
1da177e4 LT	99
	100	if (uspi->s_ncg > UFS_MAX_GROUP_LOADED && bitmap_nr >= sbi->s_cg_loaded) {
	101	ufs_panic (sb, "ufs_put_cylinder", "internal error");
	102	return;
	103	}
	104	/*
	105	* rotor is not so important data, so we put it to disk
	106	* at the end of working with cylinder
	107	*/
	108	ucg->cg_rotor = cpu_to_fs32(sb, ucpi->c_rotor);
	109	ucg->cg_frotor = cpu_to_fs32(sb, ucpi->c_frotor);
	110	ucg->cg_irotor = cpu_to_fs32(sb, ucpi->c_irotor);
9695ef16 ED	111	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
	112	for (i = 1; i < UCPI_UBH(ucpi)->count; i++) {
	113	brelse (UCPI_UBH(ucpi)->bh[i]);
1da177e4 LT	114	}
	115
	116	sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY;
abf5d15f	117	UFSD("EXIT\n");
1da177e4 LT	118	}
	119
	120	/*
	121	* Find cylinder group in cache and return it as pointer.
	122	* If cylinder group is not in cache, we will load it from disk.
	123	*
	124	* The cache is managed by LRU algorithm.
	125	*/
	126	struct ufs_cg_private_info * ufs_load_cylinder (
	127	struct super_block * sb, unsigned cgno)
	128	{
	129	struct ufs_sb_info * sbi = UFS_SB(sb);
	130	struct ufs_sb_private_info * uspi;
	131	struct ufs_cg_private_info * ucpi;
	132	unsigned cg, i, j;
	133
abf5d15f	134	UFSD("ENTER, cgno %u\n", cgno);
1da177e4 LT	135
	136	uspi = sbi->s_uspi;
	137	if (cgno >= uspi->s_ncg) {
	138	ufs_panic (sb, "ufs_load_cylinder", "internal error, high number of cg");
	139	return NULL;
	140	}
	141	/*
	142	* Cylinder group number cg it in cache and it was last used
	143	*/
	144	if (sbi->s_cgno[0] == cgno) {
abf5d15f	145	UFSD("EXIT\n");
1da177e4 LT	146	return sbi->s_ucpi[0];
	147	}
	148	/*
	149	* Number of cylinder groups is not higher than UFS_MAX_GROUP_LOADED
	150	*/
	151	if (uspi->s_ncg <= UFS_MAX_GROUP_LOADED) {
	152	if (sbi->s_cgno[cgno] != UFS_CGNO_EMPTY) {
	153	if (sbi->s_cgno[cgno] != cgno) {
	154	ufs_panic (sb, "ufs_load_cylinder", "internal error, wrong number of cg in cache");
abf5d15f	155	UFSD("EXIT (FAILED)\n");
1da177e4 LT	156	return NULL;
	157	}
	158	else {
abf5d15f	159	UFSD("EXIT\n");
1da177e4 LT	160	return sbi->s_ucpi[cgno];
	161	}
	162	} else {
	163	ufs_read_cylinder (sb, cgno, cgno);
abf5d15f	164	UFSD("EXIT\n");
1da177e4 LT	165	return sbi->s_ucpi[cgno];
	166	}
	167	}
	168	/*
	169	* Cylinder group number cg is in cache but it was not last used,
	170	* we will move to the first position
	171	*/
	172	for (i = 0; i < sbi->s_cg_loaded && sbi->s_cgno[i] != cgno; i++);
	173	if (i < sbi->s_cg_loaded && sbi->s_cgno[i] == cgno) {
	174	cg = sbi->s_cgno[i];
	175	ucpi = sbi->s_ucpi[i];
	176	for (j = i; j > 0; j--) {
	177	sbi->s_cgno[j] = sbi->s_cgno[j-1];
	178	sbi->s_ucpi[j] = sbi->s_ucpi[j-1];
	179	}
	180	sbi->s_cgno[0] = cg;
	181	sbi->s_ucpi[0] = ucpi;
	182	/*
	183	* Cylinder group number cg is not in cache, we will read it from disk
	184	* and put it to the first position
	185	*/
	186	} else {
	187	if (sbi->s_cg_loaded < UFS_MAX_GROUP_LOADED)
	188	sbi->s_cg_loaded++;
	189	else
	190	ufs_put_cylinder (sb, UFS_MAX_GROUP_LOADED-1);
	191	ucpi = sbi->s_ucpi[sbi->s_cg_loaded - 1];
	192	for (j = sbi->s_cg_loaded - 1; j > 0; j--) {
	193	sbi->s_cgno[j] = sbi->s_cgno[j-1];
	194	sbi->s_ucpi[j] = sbi->s_ucpi[j-1];
	195	}
	196	sbi->s_ucpi[0] = ucpi;
	197	ufs_read_cylinder (sb, cgno, 0);
	198	}
abf5d15f	199	UFSD("EXIT\n");
1da177e4 LT	200	return sbi->s_ucpi[0];
1da177e4 LT	201	}