1 files changed, 240 insertions, 0 deletions

diff --git a/fs/sysv/ialloc.c b/fs/sysv/ialloc.c
new file mode 100644
index 000000000000..9b585d1081c0
--- /dev/null
+++ b/fs/sysv/ialloc.c
@@ -0,0 +1,240 @@
+/*
+ *  linux/fs/sysv/ialloc.c
+ *
+ *  minix/bitmap.c
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext/freelists.c
+ *  Copyright (C) 1992  Remy Card (card@masi.ibp.fr)
+ *
+ *  xenix/alloc.c
+ *  Copyright (C) 1992  Doug Evans
+ *
+ *  coh/alloc.c
+ *  Copyright (C) 1993  Pascal Haible, Bruno Haible
+ *
+ *  sysv/ialloc.c
+ *  Copyright (C) 1993  Bruno Haible
+ *
+ *  This file contains code for allocating/freeing inodes.
+ */
+
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/buffer_head.h>
+#include "sysv.h"
+
+/* We don't trust the value of
+   sb->sv_sbd2->s_tinode = *sb->sv_sb_total_free_inodes
+   but we nevertheless keep it up to date. */
+
+/* An inode on disk is considered free if both i_mode == 0 and i_nlink == 0. */
+
+/* return &sb->sv_sb_fic_inodes[i] = &sbd->s_inode[i]; */
+static inline sysv_ino_t *
+sv_sb_fic_inode(struct super_block * sb, unsigned int i)
+{
+        struct sysv_sb_info *sbi = SYSV_SB(sb);
+
+        if (sbi->s_bh1 == sbi->s_bh2)
+                return &sbi->s_sb_fic_inodes[i];
+        else {
+                /* 512 byte Xenix FS */
+                unsigned int offset = offsetof(struct xenix_super_block, s_inode[i]);
+                if (offset < 512)
+                        return (sysv_ino_t*)(sbi->s_sbd1 + offset);
+                else
+                        return (sysv_ino_t*)(sbi->s_sbd2 + offset);
+        }
+}
+
+struct sysv_inode *
+sysv_raw_inode(struct super_block *sb, unsigned ino, struct buffer_head **bh)
+{
+        struct sysv_sb_info *sbi = SYSV_SB(sb);
+        struct sysv_inode *res;
+        int block = sbi->s_firstinodezone + sbi->s_block_base;
+
+        block += (ino-1) >> sbi->s_inodes_per_block_bits;
+        *bh = sb_bread(sb, block);
+        if (!*bh)
+                return NULL;
+        res = (struct sysv_inode *)(*bh)->b_data;
+        return res + ((ino-1) & sbi->s_inodes_per_block_1);
+}
+
+static int refill_free_cache(struct super_block *sb)
+{
+        struct sysv_sb_info *sbi = SYSV_SB(sb);
+        struct buffer_head * bh;
+        struct sysv_inode * raw_inode;
+        int i = 0, ino;
+
+        ino = SYSV_ROOT_INO+1;
+        raw_inode = sysv_raw_inode(sb, ino, &bh);
+        if (!raw_inode)
+                goto out;
+        while (ino <= sbi->s_ninodes) {
+                if (raw_inode->i_mode == 0 && raw_inode->i_nlink == 0) {
+                        *sv_sb_fic_inode(sb,i++) = cpu_to_fs16(SYSV_SB(sb), ino);
+                        if (i == sbi->s_fic_size)
+                                break;
+                }
+                if ((ino++ & sbi->s_inodes_per_block_1) == 0) {
+                        brelse(bh);
+                        raw_inode = sysv_raw_inode(sb, ino, &bh);
+                        if (!raw_inode)
+                                goto out;
+                } else
+                        raw_inode++;
+        }
+        brelse(bh);
+out:
+        return i;
+}
+
+void sysv_free_inode(struct inode * inode)
+{
+        struct super_block *sb = inode->i_sb;
+        struct sysv_sb_info *sbi = SYSV_SB(sb);
+        unsigned int ino;
+        struct buffer_head * bh;
+        struct sysv_inode * raw_inode;
+        unsigned count;
+
+        sb = inode->i_sb;
+        ino = inode->i_ino;
+        if (ino <= SYSV_ROOT_INO || ino > sbi->s_ninodes) {
+                printk("sysv_free_inode: inode 0,1,2 or nonexistent inode\n");
+                return;
+        }
+        raw_inode = sysv_raw_inode(sb, ino, &bh);
+        clear_inode(inode);
+        if (!raw_inode) {
+                printk("sysv_free_inode: unable to read inode block on device "
+                       "%s\n", inode->i_sb->s_id);
+                return;
+        }
+        lock_super(sb);
+        count = fs16_to_cpu(sbi, *sbi->s_sb_fic_count);
+        if (count < sbi->s_fic_size) {
+                *sv_sb_fic_inode(sb,count++) = cpu_to_fs16(sbi, ino);
+                *sbi->s_sb_fic_count = cpu_to_fs16(sbi, count);
+        }
+        fs16_add(sbi, sbi->s_sb_total_free_inodes, 1);
+        dirty_sb(sb);
+        memset(raw_inode, 0, sizeof(struct sysv_inode));
+        mark_buffer_dirty(bh);
+        unlock_super(sb);
+        brelse(bh);
+}
+
+struct inode * sysv_new_inode(const struct inode * dir, mode_t mode)
+{
+        struct super_block *sb = dir->i_sb;
+        struct sysv_sb_info *sbi = SYSV_SB(sb);
+        struct inode *inode;
+        sysv_ino_t ino;
+        unsigned count;
+
+        inode = new_inode(sb);
+        if (!inode)
+                return ERR_PTR(-ENOMEM);
+
+        lock_super(sb);
+        count = fs16_to_cpu(sbi, *sbi->s_sb_fic_count);
+        if (count == 0 || (*sv_sb_fic_inode(sb,count-1) == 0)) {
+                count = refill_free_cache(sb);
+                if (count == 0) {
+                        iput(inode);
+                        unlock_super(sb);
+                        return ERR_PTR(-ENOSPC);
+                }
+        }
+        /* Now count > 0. */
+        ino = *sv_sb_fic_inode(sb,--count);
+        *sbi->s_sb_fic_count = cpu_to_fs16(sbi, count);
+        fs16_add(sbi, sbi->s_sb_total_free_inodes, -1);
+        dirty_sb(sb);
+        
+        if (dir->i_mode & S_ISGID) {
+                inode->i_gid = dir->i_gid;
+                if (S_ISDIR(mode))
+                        mode |= S_ISGID;
+        } else
+                inode->i_gid = current->fsgid;
+
+        inode->i_uid = current->fsuid;
+        inode->i_ino = fs16_to_cpu(sbi, ino);
+        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+        inode->i_blocks = inode->i_blksize = 0;
+        memset(SYSV_I(inode)->i_data, 0, sizeof(SYSV_I(inode)->i_data));
+        SYSV_I(inode)->i_dir_start_lookup = 0;
+        insert_inode_hash(inode);
+        mark_inode_dirty(inode);
+
+        inode->i_mode = mode;           /* for sysv_write_inode() */
+        sysv_write_inode(inode, 0);     /* ensure inode not allocated again */
+        mark_inode_dirty(inode);        /* cleared by sysv_write_inode() */
+        /* That's it. */
+        unlock_super(sb);
+        return inode;
+}
+
+unsigned long sysv_count_free_inodes(struct super_block * sb)
+{
+        struct sysv_sb_info *sbi = SYSV_SB(sb);
+        struct buffer_head * bh;
+        struct sysv_inode * raw_inode;
+        int ino, count, sb_count;
+
+        lock_super(sb);
+
+        sb_count = fs16_to_cpu(sbi, *sbi->s_sb_total_free_inodes);
+
+        if (0)
+                goto trust_sb;
+
+        /* this causes a lot of disk traffic ... */
+        count = 0;
+        ino = SYSV_ROOT_INO+1;
+        raw_inode = sysv_raw_inode(sb, ino, &bh);
+        if (!raw_inode)
+                goto Eio;
+        while (ino <= sbi->s_ninodes) {
+                if (raw_inode->i_mode == 0 && raw_inode->i_nlink == 0)
+                        count++;
+                if ((ino++ & sbi->s_inodes_per_block_1) == 0) {
+                        brelse(bh);
+                        raw_inode = sysv_raw_inode(sb, ino, &bh);
+                        if (!raw_inode)
+                                goto Eio;
+                } else
+                        raw_inode++;
+        }
+        brelse(bh);
+        if (count != sb_count)
+                goto Einval;
+out:
+        unlock_super(sb);
+        return count;
+
+Einval:
+        printk("sysv_count_free_inodes: "
+                "free inode count was %d, correcting to %d\n",
+                sb_count, count);
+        if (!(sb->s_flags & MS_RDONLY)) {
+                *sbi->s_sb_total_free_inodes = cpu_to_fs16(SYSV_SB(sb), count);
+                dirty_sb(sb);
+        }
+        goto out;
+
+Eio:
+        printk("sysv_count_free_inodes: unable to read inode table\n");
+trust_sb:
+        count = sb_count;
+        goto out;
+}