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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [sysv/] [ialloc.c] - Blame information for rev 1775

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Line No. Rev Author Line
1 199 simons
/*
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 *  linux/fs/sysv/ialloc.c
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 *
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 *  minix/bitmap.c
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 *  Copyright (C) 1991, 1992  Linus Torvalds
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 *
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 *  ext/freelists.c
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 *  Copyright (C) 1992  Remy Card (card@masi.ibp.fr)
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 *
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 *  xenix/alloc.c
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 *  Copyright (C) 1992  Doug Evans
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 *
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 *  coh/alloc.c
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 *  Copyright (C) 1993  Pascal Haible, Bruno Haible
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 *
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 *  sysv/ialloc.c
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 *  Copyright (C) 1993  Bruno Haible
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 *
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 *  This file contains code for allocating/freeing inodes.
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 */
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/sysv_fs.h>
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#include <linux/stddef.h>
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#include <linux/stat.h>
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#include <linux/string.h>
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#include <linux/locks.h>
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/* We don't trust the value of
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   sb->sv_sbd2->s_tinode = *sb->sv_sb_total_free_inodes
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   but we nevertheless keep it up to date. */
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/* An inode on disk is considered free if both i_mode == 0 and i_nlink == 0. */
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/* return &sb->sv_sb_fic_inodes[i] = &sbd->s_inode[i]; */
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static inline sysv_ino_t * sv_sb_fic_inode (struct super_block * sb, unsigned int i)
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{
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        if (sb->sv_bh1 == sb->sv_bh2)
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                return &sb->sv_sb_fic_inodes[i];
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        else {
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                /* 512 byte Xenix FS */
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                unsigned int offset = offsetof(struct xenix_super_block, s_inode[i]);
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                if (offset < 512)
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                        return (sysv_ino_t*)(sb->sv_sbd1 + offset);
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                else
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                        return (sysv_ino_t*)(sb->sv_sbd2 + offset);
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        }
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}
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void sysv_free_inode(struct inode * inode)
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{
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        struct super_block * sb;
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        unsigned int ino;
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        struct buffer_head * bh;
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        struct sysv_inode * raw_inode;
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        if (!inode)
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                return;
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        if (!inode->i_dev) {
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                printk("sysv_free_inode: inode has no device\n");
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                return;
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        }
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        if (inode->i_count != 1) {
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                printk("sysv_free_inode: inode has count=%ld\n", inode->i_count);
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                return;
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        }
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        if (inode->i_nlink) {
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                printk("sysv_free_inode: inode has nlink=%d\n", inode->i_nlink);
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                return;
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        }
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        if (!(sb = inode->i_sb)) {
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                printk("sysv_free_inode: inode on nonexistent device\n");
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                return;
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        }
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        ino = inode->i_ino;
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        if (ino <= SYSV_ROOT_INO || ino > sb->sv_ninodes) {
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                printk("sysv_free_inode: inode 0,1,2 or nonexistent inode\n");
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                return;
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        }
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        if (!(bh = sv_bread(sb, inode->i_dev, sb->sv_firstinodezone + ((ino-1) >> sb->sv_inodes_per_block_bits)))) {
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                printk("sysv_free_inode: unable to read inode block on device "
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                       "%s\n", kdevname(inode->i_dev));
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                clear_inode(inode);
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                return;
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        }
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        raw_inode = (struct sysv_inode *) bh->b_data + ((ino-1) & sb->sv_inodes_per_block_1);
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        lock_super(sb);
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        if (*sb->sv_sb_fic_count < sb->sv_fic_size)
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                *sv_sb_fic_inode(sb,(*sb->sv_sb_fic_count)++) = ino;
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        (*sb->sv_sb_total_free_inodes)++;
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        mark_buffer_dirty(sb->sv_bh1, 1); /* super-block has been modified */
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        if (sb->sv_bh1 != sb->sv_bh2) mark_buffer_dirty(sb->sv_bh2, 1);
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        sb->s_dirt = 1; /* and needs time stamp */
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        memset(raw_inode, 0, sizeof(struct sysv_inode));
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        mark_buffer_dirty(bh, 1);
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        unlock_super(sb);
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        brelse(bh);
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        clear_inode(inode);
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}
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struct inode * sysv_new_inode(const struct inode * dir)
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{
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        struct inode * inode;
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        struct super_block * sb;
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        struct buffer_head * bh;
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        struct sysv_inode * raw_inode;
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        int i,j,ino,block;
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        if (!dir || !(inode = get_empty_inode()))
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                return NULL;
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        sb = dir->i_sb;
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        inode->i_sb = sb;
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        inode->i_flags = inode->i_sb->s_flags;
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        lock_super(sb);         /* protect against task switches */
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        if ((*sb->sv_sb_fic_count == 0)
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            || (*sv_sb_fic_inode(sb,(*sb->sv_sb_fic_count)-1) == 0) /* Applies only to SystemV2 FS */
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           ) {
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                /* Rebuild cache of free inodes: */
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                /* i : index into cache slot being filled            */
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                /* ino : inode we are trying                         */
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                /* block : firstinodezone + (ino-1)/inodes_per_block */
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                /* j : (ino-1)%inodes_per_block                      */
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                /* bh : buffer for block                             */
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                /* raw_inode : pointer to inode ino in the block     */
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                for (i = 0, ino = SYSV_ROOT_INO+1, block = sb->sv_firstinodezone, j = SYSV_ROOT_INO ; i < sb->sv_fic_size && block < sb->sv_firstdatazone ; block++, j = 0) {
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                        if (!(bh = sv_bread(sb, sb->s_dev, block))) {
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                                printk("sysv_new_inode: unable to read inode table\n");
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                                break;  /* go with what we've got */
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                                /* FIXME: Perhaps try the next block? */
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                        }
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                        raw_inode = (struct sysv_inode *) bh->b_data + j;
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                        for (; j < sb->sv_inodes_per_block && i < sb->sv_fic_size; ino++, j++, raw_inode++) {
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                                if (raw_inode->i_mode == 0 && raw_inode->i_nlink == 0)
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                                        *sv_sb_fic_inode(sb,i++) = ino;
137
                        }
138
                        brelse(bh);
139
                }
140
                if (i == 0) {
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                        iput(inode);
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                        unlock_super(sb);
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                        return NULL;    /* no inodes available */
144
                }
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                *sb->sv_sb_fic_count = i;
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        }
147
        /* Now *sb->sv_sb_fic_count > 0. */
148
        ino = *sv_sb_fic_inode(sb,--(*sb->sv_sb_fic_count));
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        mark_buffer_dirty(sb->sv_bh1, 1); /* super-block has been modified */
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        if (sb->sv_bh1 != sb->sv_bh2) mark_buffer_dirty(sb->sv_bh2, 1);
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        sb->s_dirt = 1; /* and needs time stamp */
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        inode->i_count = 1;
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        inode->i_nlink = 1;
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        inode->i_dev = sb->s_dev;
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        inode->i_uid = current->fsuid;
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        inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
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        inode->i_dirt = 1;
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        inode->i_ino = ino;
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        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
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        inode->i_op = NULL;
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        inode->i_blocks = inode->i_blksize = 0;
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        insert_inode_hash(inode);
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        /* Change directory entry: */
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        inode->i_mode = 0;               /* for sysv_write_inode() */
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        inode->i_size = 0;               /* ditto */
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        sysv_write_inode(inode);        /* ensure inode not allocated again */
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                                        /* FIXME: caller may call this too. */
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        inode->i_dirt = 1;              /* cleared by sysv_write_inode() */
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        /* That's it. */
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        (*sb->sv_sb_total_free_inodes)--;
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        mark_buffer_dirty(sb->sv_bh2, 1); /* super-block has been modified again */
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        sb->s_dirt = 1; /* and needs time stamp again */
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        unlock_super(sb);
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        return inode;
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}
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unsigned long sysv_count_free_inodes(struct super_block * sb)
178
{
179
#if 1 /* test */
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        struct buffer_head * bh;
181
        struct sysv_inode * raw_inode;
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        int j,block,count;
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184
        /* this causes a lot of disk traffic ... */
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        count = 0;
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        lock_super(sb);
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        /* i : index into cache slot being filled            */
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        /* ino : inode we are trying                         */
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        /* block : firstinodezone + (ino-1)/inodes_per_block */
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        /* j : (ino-1)%inodes_per_block                      */
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        /* bh : buffer for block                             */
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        /* raw_inode : pointer to inode ino in the block     */
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        for (block = sb->sv_firstinodezone, j = SYSV_ROOT_INO ; block < sb->sv_firstdatazone ; block++, j = 0) {
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                if (!(bh = sv_bread(sb, sb->s_dev, block))) {
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                        printk("sysv_count_free_inodes: unable to read inode table\n");
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                        break;  /* go with what we've got */
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                        /* FIXME: Perhaps try the next block? */
198
                }
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                raw_inode = (struct sysv_inode *) bh->b_data + j;
200
                for (; j < sb->sv_inodes_per_block ; j++, raw_inode++)
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                        if (raw_inode->i_mode == 0 && raw_inode->i_nlink == 0)
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                                count++;
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                brelse(bh);
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        }
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        if (count != *sb->sv_sb_total_free_inodes) {
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                printk("sysv_count_free_inodes: free inode count was %d, correcting to %d\n",(short)(*sb->sv_sb_total_free_inodes),count);
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                if (!(sb->s_flags & MS_RDONLY)) {
208
                        *sb->sv_sb_total_free_inodes = count;
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                        mark_buffer_dirty(sb->sv_bh2, 1); /* super-block has been modified */
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                        sb->s_dirt = 1; /* and needs time stamp */
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                }
212
        }
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        unlock_super(sb);
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        return count;
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#else
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        return *sb->sv_sb_total_free_inodes;
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#endif
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}
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