--- /dev/null
+/*
+ * 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];
+}
Code Review / kvmfornfv.git / blobdiff