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/*
* 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/ufs_fs.h>
#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/locks.h>
#include <asm/bitops.h>
#include <asm/byteorder.h>
#include "swab.h"
#include "util.h"
#undef UFS_CYLINDER_DEBUG
#ifdef UFS_CYLINDER_DEBUG
#define UFSD(x) printk("(%s, %d), %s:", __FILE__, __LINE__, __FUNCTION__); printk x;
#else
#define UFSD(x)
#endif
/*
* 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_private_info * uspi;
struct ufs_cg_private_info * ucpi;
struct ufs_cylinder_group * ucg;
unsigned i, j;
unsigned swab;
UFSD(("ENTER, cgno %u, bitmap_nr %u\n", cgno, bitmap_nr))
swab = sb->u.ufs_sb.s_swab;
uspi = sb->u.ufs_sb.s_uspi;
ucpi = sb->u.ufs_sb.s_ucpi[bitmap_nr];
ucg = (struct ufs_cylinder_group *)sb->u.ufs_sb.s_ucg[cgno]->b_data;
UCPI_UBH->fragment = ufs_cgcmin(cgno);
UCPI_UBH->count = uspi->s_cgsize >> sb->s_blocksize_bits;
/*
* We have already the first fragment of cylinder group block in buffer
*/
UCPI_UBH->bh[0] = sb->u.ufs_sb.s_ucg[cgno];
for (i = 1; i < UCPI_UBH->count; i++)
if (!(UCPI_UBH->bh[i] = bread (sb->s_dev, UCPI_UBH->fragment + i, sb->s_blocksize)))
goto failed;
sb->u.ufs_sb.s_cgno[bitmap_nr] = cgno;
ucpi->c_cgx = SWAB32(ucg->cg_cgx);
ucpi->c_ncyl = SWAB16(ucg->cg_ncyl);
ucpi->c_niblk = SWAB16(ucg->cg_niblk);
ucpi->c_ndblk = SWAB32(ucg->cg_ndblk);
ucpi->c_rotor = SWAB32(ucg->cg_rotor);
ucpi->c_frotor = SWAB32(ucg->cg_frotor);
ucpi->c_irotor = SWAB32(ucg->cg_irotor);
ucpi->c_btotoff = SWAB32(ucg->cg_btotoff);
ucpi->c_boff = SWAB32(ucg->cg_boff);
ucpi->c_iusedoff = SWAB32(ucg->cg_iusedoff);
ucpi->c_freeoff = SWAB32(ucg->cg_freeoff);
ucpi->c_nextfreeoff = SWAB32(ucg->cg_nextfreeoff);
ucpi->c_clustersumoff = SWAB32(ucg->cg_u.cg_44.cg_clustersumoff);
ucpi->c_clusteroff = SWAB32(ucg->cg_u.cg_44.cg_clusteroff);
ucpi->c_nclusterblks = SWAB32(ucg->cg_u.cg_44.cg_nclusterblks);
UFSD(("EXIT\n"))
return;
failed:
for (j = 1; j < i; j++)
brelse (sb->u.ufs_sb.s_ucg[j]);
sb->u.ufs_sb.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, does'n 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_private_info * uspi;
struct ufs_cg_private_info * ucpi;
struct ufs_cylinder_group * ucg;
unsigned i;
unsigned swab;
UFSD(("ENTER, bitmap_nr %u\n", bitmap_nr))
swab = sb->u.ufs_sb.s_swab;
uspi = sb->u.ufs_sb.s_uspi;
if (sb->u.ufs_sb.s_cgno[bitmap_nr] == UFS_CGNO_EMPTY) {
UFSD(("EXIT\n"))
return;
}
ucpi = sb->u.ufs_sb.s_ucpi[bitmap_nr];
ucg = ubh_get_ucg(UCPI_UBH);
if (uspi->s_ncg > UFS_MAX_GROUP_LOADED && bitmap_nr >= sb->u.ufs_sb.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 = SWAB32(ucpi->c_rotor);
ucg->cg_frotor = SWAB32(ucpi->c_frotor);
ucg->cg_irotor = SWAB32(ucpi->c_irotor);
ubh_mark_buffer_dirty (UCPI_UBH, 1);
for (i = 1; i < UCPI_UBH->count; i++) {
brelse (UCPI_UBH->bh[i]);
}
sb->u.ufs_sb.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 alghoritm.
*/
struct ufs_cg_private_info * ufs_load_cylinder (
struct super_block * sb, unsigned cgno)
{
struct ufs_sb_private_info * uspi;
struct ufs_cg_private_info * ucpi;
unsigned cg, i, j;
UFSD(("ENTER, cgno %u\n", cgno))
uspi = sb->u.ufs_sb.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 (sb->u.ufs_sb.s_cgno[0] == cgno) {
UFSD(("EXIT\n"))
return sb->u.ufs_sb.s_ucpi[0];
}
/*
* Number of cylinder groups is not higher than UFS_MAX_GROUP_LOADED
*/
if (uspi->s_ncg <= UFS_MAX_GROUP_LOADED) {
if (sb->u.ufs_sb.s_cgno[cgno] != UFS_CGNO_EMPTY) {
if (sb->u.ufs_sb.s_cgno[cgno] != cgno) {
ufs_panic (sb, "ufs_load_cylinder", "internal error, wrog number of cg in cache");
UFSD(("EXIT (FAILED)\n"))
return NULL;
}
else {
UFSD(("EXIT\n"))
return sb->u.ufs_sb.s_ucpi[cgno];
}
} else {
ufs_read_cylinder (sb, cgno, cgno);
UFSD(("EXIT\n"))
return sb->u.ufs_sb.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 < sb->u.ufs_sb.s_cg_loaded && sb->u.ufs_sb.s_cgno[i] != cgno; i++);
if (i < sb->u.ufs_sb.s_cg_loaded && sb->u.ufs_sb.s_cgno[i] == cgno) {
cg = sb->u.ufs_sb.s_cgno[i];
ucpi = sb->u.ufs_sb.s_ucpi[i];
for (j = i; j > 0; j--) {
sb->u.ufs_sb.s_cgno[j] = sb->u.ufs_sb.s_cgno[j-1];
sb->u.ufs_sb.s_ucpi[j] = sb->u.ufs_sb.s_ucpi[j-1];
}
sb->u.ufs_sb.s_cgno[0] = cg;
sb->u.ufs_sb.s_ucpi[0] = ucpi;
/*
* Cylinder group number cg is not in cache, we will read it from disk
* and put it to the first possition
*/
} else {
if (sb->u.ufs_sb.s_cg_loaded < UFS_MAX_GROUP_LOADED)
sb->u.ufs_sb.s_cg_loaded++;
else
ufs_put_cylinder (sb, UFS_MAX_GROUP_LOADED-1);
ucpi = sb->u.ufs_sb.s_ucpi[sb->u.ufs_sb.s_cg_loaded - 1];
for (j = sb->u.ufs_sb.s_cg_loaded - 1; j > 0; j--) {
sb->u.ufs_sb.s_cgno[j] = sb->u.ufs_sb.s_cgno[j-1];
sb->u.ufs_sb.s_ucpi[j] = sb->u.ufs_sb.s_ucpi[j-1];
}
sb->u.ufs_sb.s_ucpi[0] = ucpi;
ufs_read_cylinder (sb, cgno, 0);
}
UFSD(("EXIT\n"))
return sb->u.ufs_sb.s_ucpi[0];
}
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