1 files changed, 209 insertions, 0 deletions

diff --git a/fs/ufs/cylinder.c b/fs/ufs/cylinder.c
new file mode 100644
index 000000000000..14abb8b835f7
--- /dev/null
+++ b/fs/ufs/cylinder.c
@@ -0,0 +1,209 @@
+/*
+ *  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/time.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/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_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->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] = sbi->s_ucg[cgno];
+        for (i = 1; i < UCPI_UBH->count; i++)
+                if (!(UCPI_UBH->bh[i] = sb_bread(sb, UCPI_UBH->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);
+
+        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);
+        for (i = 1; i < UCPI_UBH->count; i++) {
+                brelse (UCPI_UBH->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];
+}