diff options
Diffstat (limited to '')
| -rw-r--r-- | fs/ufs/cylinder.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/fs/ufs/cylinder.c b/fs/ufs/cylinder.c new file mode 100644 index 0000000000..1abe5454de --- /dev/null +++ b/fs/ufs/cylinder.c @@ -0,0 +1,202 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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]; +} |