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202 lines
5.7 KiB
202 lines
5.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* linux/fs/ufs/cylinder.c |
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* |
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* Copyright (C) 1998 |
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* Daniel Pirkl <[email protected]> |
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* Charles University, Faculty of Mathematics and Physics |
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* |
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* ext2 - inode (block) bitmap caching inspired |
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*/ |
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#include <linux/fs.h> |
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#include <linux/time.h> |
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#include <linux/stat.h> |
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#include <linux/string.h> |
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#include <linux/bitops.h> |
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#include <asm/byteorder.h> |
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#include "ufs_fs.h" |
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#include "ufs.h" |
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#include "swab.h" |
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#include "util.h" |
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/* |
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* Read cylinder group into cache. The memory space for ufs_cg_private_info |
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* structure is already allocated during ufs_read_super. |
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*/ |
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static void ufs_read_cylinder (struct super_block * sb, |
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unsigned cgno, unsigned bitmap_nr) |
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{ |
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struct ufs_sb_info * sbi = UFS_SB(sb); |
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struct ufs_sb_private_info * uspi; |
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struct ufs_cg_private_info * ucpi; |
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struct ufs_cylinder_group * ucg; |
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unsigned i, j; |
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UFSD("ENTER, cgno %u, bitmap_nr %u\n", cgno, bitmap_nr); |
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uspi = sbi->s_uspi; |
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ucpi = sbi->s_ucpi[bitmap_nr]; |
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ucg = (struct ufs_cylinder_group *)sbi->s_ucg[cgno]->b_data; |
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UCPI_UBH(ucpi)->fragment = ufs_cgcmin(cgno); |
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UCPI_UBH(ucpi)->count = uspi->s_cgsize >> sb->s_blocksize_bits; |
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/* |
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* We have already the first fragment of cylinder group block in buffer |
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*/ |
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UCPI_UBH(ucpi)->bh[0] = sbi->s_ucg[cgno]; |
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for (i = 1; i < UCPI_UBH(ucpi)->count; i++) |
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if (!(UCPI_UBH(ucpi)->bh[i] = sb_bread(sb, UCPI_UBH(ucpi)->fragment + i))) |
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goto failed; |
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sbi->s_cgno[bitmap_nr] = cgno; |
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ucpi->c_cgx = fs32_to_cpu(sb, ucg->cg_cgx); |
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ucpi->c_ncyl = fs16_to_cpu(sb, ucg->cg_ncyl); |
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ucpi->c_niblk = fs16_to_cpu(sb, ucg->cg_niblk); |
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ucpi->c_ndblk = fs32_to_cpu(sb, ucg->cg_ndblk); |
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ucpi->c_rotor = fs32_to_cpu(sb, ucg->cg_rotor); |
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ucpi->c_frotor = fs32_to_cpu(sb, ucg->cg_frotor); |
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ucpi->c_irotor = fs32_to_cpu(sb, ucg->cg_irotor); |
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ucpi->c_btotoff = fs32_to_cpu(sb, ucg->cg_btotoff); |
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ucpi->c_boff = fs32_to_cpu(sb, ucg->cg_boff); |
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ucpi->c_iusedoff = fs32_to_cpu(sb, ucg->cg_iusedoff); |
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ucpi->c_freeoff = fs32_to_cpu(sb, ucg->cg_freeoff); |
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ucpi->c_nextfreeoff = fs32_to_cpu(sb, ucg->cg_nextfreeoff); |
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ucpi->c_clustersumoff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clustersumoff); |
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ucpi->c_clusteroff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clusteroff); |
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ucpi->c_nclusterblks = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_nclusterblks); |
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UFSD("EXIT\n"); |
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return; |
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failed: |
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for (j = 1; j < i; j++) |
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brelse (sbi->s_ucg[j]); |
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sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY; |
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ufs_error (sb, "ufs_read_cylinder", "can't read cylinder group block %u", cgno); |
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} |
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/* |
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* Remove cylinder group from cache, doesn't release memory |
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* allocated for cylinder group (this is done at ufs_put_super only). |
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*/ |
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void ufs_put_cylinder (struct super_block * sb, unsigned bitmap_nr) |
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{ |
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struct ufs_sb_info * sbi = UFS_SB(sb); |
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struct ufs_sb_private_info * uspi; |
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struct ufs_cg_private_info * ucpi; |
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struct ufs_cylinder_group * ucg; |
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unsigned i; |
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UFSD("ENTER, bitmap_nr %u\n", bitmap_nr); |
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uspi = sbi->s_uspi; |
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if (sbi->s_cgno[bitmap_nr] == UFS_CGNO_EMPTY) { |
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UFSD("EXIT\n"); |
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return; |
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} |
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ucpi = sbi->s_ucpi[bitmap_nr]; |
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ucg = ubh_get_ucg(UCPI_UBH(ucpi)); |
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if (uspi->s_ncg > UFS_MAX_GROUP_LOADED && bitmap_nr >= sbi->s_cg_loaded) { |
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ufs_panic (sb, "ufs_put_cylinder", "internal error"); |
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return; |
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} |
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/* |
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* rotor is not so important data, so we put it to disk |
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* at the end of working with cylinder |
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*/ |
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ucg->cg_rotor = cpu_to_fs32(sb, ucpi->c_rotor); |
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ucg->cg_frotor = cpu_to_fs32(sb, ucpi->c_frotor); |
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ucg->cg_irotor = cpu_to_fs32(sb, ucpi->c_irotor); |
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ubh_mark_buffer_dirty (UCPI_UBH(ucpi)); |
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for (i = 1; i < UCPI_UBH(ucpi)->count; i++) { |
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brelse (UCPI_UBH(ucpi)->bh[i]); |
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} |
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sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY; |
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UFSD("EXIT\n"); |
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} |
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/* |
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* Find cylinder group in cache and return it as pointer. |
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* If cylinder group is not in cache, we will load it from disk. |
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* |
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* The cache is managed by LRU algorithm. |
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*/ |
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struct ufs_cg_private_info * ufs_load_cylinder ( |
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struct super_block * sb, unsigned cgno) |
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{ |
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struct ufs_sb_info * sbi = UFS_SB(sb); |
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struct ufs_sb_private_info * uspi; |
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struct ufs_cg_private_info * ucpi; |
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unsigned cg, i, j; |
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UFSD("ENTER, cgno %u\n", cgno); |
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uspi = sbi->s_uspi; |
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if (cgno >= uspi->s_ncg) { |
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ufs_panic (sb, "ufs_load_cylinder", "internal error, high number of cg"); |
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return NULL; |
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} |
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/* |
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* Cylinder group number cg it in cache and it was last used |
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*/ |
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if (sbi->s_cgno[0] == cgno) { |
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UFSD("EXIT\n"); |
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return sbi->s_ucpi[0]; |
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} |
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/* |
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* Number of cylinder groups is not higher than UFS_MAX_GROUP_LOADED |
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*/ |
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if (uspi->s_ncg <= UFS_MAX_GROUP_LOADED) { |
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if (sbi->s_cgno[cgno] != UFS_CGNO_EMPTY) { |
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if (sbi->s_cgno[cgno] != cgno) { |
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ufs_panic (sb, "ufs_load_cylinder", "internal error, wrong number of cg in cache"); |
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UFSD("EXIT (FAILED)\n"); |
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return NULL; |
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} |
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else { |
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UFSD("EXIT\n"); |
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return sbi->s_ucpi[cgno]; |
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} |
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} else { |
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ufs_read_cylinder (sb, cgno, cgno); |
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UFSD("EXIT\n"); |
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return sbi->s_ucpi[cgno]; |
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} |
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} |
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/* |
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* Cylinder group number cg is in cache but it was not last used, |
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* we will move to the first position |
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*/ |
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for (i = 0; i < sbi->s_cg_loaded && sbi->s_cgno[i] != cgno; i++); |
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if (i < sbi->s_cg_loaded && sbi->s_cgno[i] == cgno) { |
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cg = sbi->s_cgno[i]; |
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ucpi = sbi->s_ucpi[i]; |
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for (j = i; j > 0; j--) { |
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sbi->s_cgno[j] = sbi->s_cgno[j-1]; |
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sbi->s_ucpi[j] = sbi->s_ucpi[j-1]; |
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} |
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sbi->s_cgno[0] = cg; |
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sbi->s_ucpi[0] = ucpi; |
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/* |
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* Cylinder group number cg is not in cache, we will read it from disk |
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* and put it to the first position |
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*/ |
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} else { |
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if (sbi->s_cg_loaded < UFS_MAX_GROUP_LOADED) |
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sbi->s_cg_loaded++; |
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else |
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ufs_put_cylinder (sb, UFS_MAX_GROUP_LOADED-1); |
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ucpi = sbi->s_ucpi[sbi->s_cg_loaded - 1]; |
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for (j = sbi->s_cg_loaded - 1; j > 0; j--) { |
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sbi->s_cgno[j] = sbi->s_cgno[j-1]; |
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sbi->s_ucpi[j] = sbi->s_ucpi[j-1]; |
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} |
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sbi->s_ucpi[0] = ucpi; |
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ufs_read_cylinder (sb, cgno, 0); |
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} |
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UFSD("EXIT\n"); |
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return sbi->s_ucpi[0]; |
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}
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