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root/fs/sysv/inode.c

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DEFINITIONS

This source file includes following definitions.
  1. sysv_write_super
  2. sysv_remount
  3. sysv_put_super
  4. sysv_statfs
  5. read3byte
  6. write3byte
  7. sysv_set_inode
  8. sysv_iget
  9. sysv_update_inode
  10. sysv_write_inode
  11. sysv_sync_inode
  12. sysv_delete_inode
  13. sysv_alloc_inode
  14. sysv_destroy_inode
  15. init_once
  16. sysv_init_icache
  17. sysv_destroy_icache

/*
 *  linux/fs/sysv/inode.c
 *
 *  minix/inode.c
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  xenix/inode.c
 *  Copyright (C) 1992  Doug Evans
 *
 *  coh/inode.c
 *  Copyright (C) 1993  Pascal Haible, Bruno Haible
 *
 *  sysv/inode.c
 *  Copyright (C) 1993  Paul B. Monday
 *
 *  sysv/inode.c
 *  Copyright (C) 1993  Bruno Haible
 *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
 *
 *  This file contains code for allocating/freeing inodes and for read/writing
 *  the superblock.
 */

#include <linux/smp_lock.h>
#include <linux/highuid.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <asm/byteorder.h>
#include "sysv.h"

/* This is only called on sync() and umount(), when s_dirt=1. */
static void sysv_write_super(struct super_block *sb)
{
        struct sysv_sb_info *sbi = SYSV_SB(sb);
        unsigned long time = get_seconds(), old_time;

        lock_kernel();
        if (sb->s_flags & MS_RDONLY)
                goto clean;

        /*
         * If we are going to write out the super block,
         * then attach current time stamp.
         * But if the filesystem was marked clean, keep it clean.
         */
        old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
        if (sbi->s_type == FSTYPE_SYSV4) {
                if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
                        *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
                *sbi->s_sb_time = cpu_to_fs32(sbi, time);
                mark_buffer_dirty(sbi->s_bh2);
        }
clean:
        sb->s_dirt = 0;
        unlock_kernel();
}

static int sysv_remount(struct super_block *sb, int *flags, char *data)
{
        struct sysv_sb_info *sbi = SYSV_SB(sb);
        if (sbi->s_forced_ro)
                *flags |= MS_RDONLY;
        if (!(*flags & MS_RDONLY))
                sb->s_dirt = 1;
        return 0;
}

static void sysv_put_super(struct super_block *sb)
{
        struct sysv_sb_info *sbi = SYSV_SB(sb);

        if (!(sb->s_flags & MS_RDONLY)) {
                /* XXX ext2 also updates the state here */
                mark_buffer_dirty(sbi->s_bh1);
                if (sbi->s_bh1 != sbi->s_bh2)
                        mark_buffer_dirty(sbi->s_bh2);
        }

        brelse(sbi->s_bh1);
        if (sbi->s_bh1 != sbi->s_bh2)
                brelse(sbi->s_bh2);

        kfree(sbi);
}

static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
{
        struct super_block *sb = dentry->d_sb;
        struct sysv_sb_info *sbi = SYSV_SB(sb);

        buf->f_type = sb->s_magic;
        buf->f_bsize = sb->s_blocksize;
        buf->f_blocks = sbi->s_ndatazones;
        buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
        buf->f_files = sbi->s_ninodes;
        buf->f_ffree = sysv_count_free_inodes(sb);
        buf->f_namelen = SYSV_NAMELEN;
        return 0;
}

/* 
 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
 */
static inline void read3byte(struct sysv_sb_info *sbi,
        unsigned char * from, unsigned char * to)
{
        if (sbi->s_bytesex == BYTESEX_PDP) {
                to[0] = from[0];
                to[1] = 0;
                to[2] = from[1];
                to[3] = from[2];
        } else if (sbi->s_bytesex == BYTESEX_LE) {
                to[0] = from[0];
                to[1] = from[1];
                to[2] = from[2];
                to[3] = 0;
        } else {
                to[0] = 0;
                to[1] = from[0];
                to[2] = from[1];
                to[3] = from[2];
        }
}

static inline void write3byte(struct sysv_sb_info *sbi,
        unsigned char * from, unsigned char * to)
{
        if (sbi->s_bytesex == BYTESEX_PDP) {
                to[0] = from[0];
                to[1] = from[2];
                to[2] = from[3];
        } else if (sbi->s_bytesex == BYTESEX_LE) {
                to[0] = from[0];
                to[1] = from[1];
                to[2] = from[2];
        } else {
                to[0] = from[1];
                to[1] = from[2];
                to[2] = from[3];
        }
}

static const struct inode_operations sysv_symlink_inode_operations = {
        .readlink       = generic_readlink,
        .follow_link    = page_follow_link_light,
        .put_link       = page_put_link,
        .getattr        = sysv_getattr,
};

void sysv_set_inode(struct inode *inode, dev_t rdev)
{
        if (S_ISREG(inode->i_mode)) {
                inode->i_op = &sysv_file_inode_operations;
                inode->i_fop = &sysv_file_operations;
                inode->i_mapping->a_ops = &sysv_aops;
        } else if (S_ISDIR(inode->i_mode)) {
                inode->i_op = &sysv_dir_inode_operations;
                inode->i_fop = &sysv_dir_operations;
                inode->i_mapping->a_ops = &sysv_aops;
        } else if (S_ISLNK(inode->i_mode)) {
                if (inode->i_blocks) {
                        inode->i_op = &sysv_symlink_inode_operations;
                        inode->i_mapping->a_ops = &sysv_aops;
                } else
                        inode->i_op = &sysv_fast_symlink_inode_operations;
        } else
                init_special_inode(inode, inode->i_mode, rdev);
}

struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
{
        struct sysv_sb_info * sbi = SYSV_SB(sb);
        struct buffer_head * bh;
        struct sysv_inode * raw_inode;
        struct sysv_inode_info * si;
        struct inode *inode;
        unsigned int block;

        if (!ino || ino > sbi->s_ninodes) {
                printk("Bad inode number on dev %s: %d is out of range\n",
                       sb->s_id, ino);
                return ERR_PTR(-EIO);
        }

        inode = iget_locked(sb, ino);
        if (!inode)
                return ERR_PTR(-ENOMEM);
        if (!(inode->i_state & I_NEW))
                return inode;

        raw_inode = sysv_raw_inode(sb, ino, &bh);
        if (!raw_inode) {
                printk("Major problem: unable to read inode from dev %s\n",
                       inode->i_sb->s_id);
                goto bad_inode;
        }
        /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
        inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
        inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
        inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
        inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
        inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
        inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
        inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
        inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
        inode->i_ctime.tv_nsec = 0;
        inode->i_atime.tv_nsec = 0;
        inode->i_mtime.tv_nsec = 0;
        inode->i_blocks = 0;

        si = SYSV_I(inode);
        for (block = 0; block < 10+1+1+1; block++)
                read3byte(sbi, &raw_inode->i_data[3*block],
                                (u8 *)&si->i_data[block]);
        brelse(bh);
        si->i_dir_start_lookup = 0;
        if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
                sysv_set_inode(inode,
                               old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
        else
                sysv_set_inode(inode, 0);
        unlock_new_inode(inode);
        return inode;

bad_inode:
        iget_failed(inode);
        return ERR_PTR(-EIO);
}

static struct buffer_head * sysv_update_inode(struct inode * inode)
{
        struct super_block * sb = inode->i_sb;
        struct sysv_sb_info * sbi = SYSV_SB(sb);
        struct buffer_head * bh;
        struct sysv_inode * raw_inode;
        struct sysv_inode_info * si;
        unsigned int ino, block;

        ino = inode->i_ino;
        if (!ino || ino > sbi->s_ninodes) {
                printk("Bad inode number on dev %s: %d is out of range\n",
                       inode->i_sb->s_id, ino);
                return NULL;
        }
        raw_inode = sysv_raw_inode(sb, ino, &bh);
        if (!raw_inode) {
                printk("unable to read i-node block\n");
                return NULL;
        }

        raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
        raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
        raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
        raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
        raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
        raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
        raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
        raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);

        si = SYSV_I(inode);
        if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
                si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
        for (block = 0; block < 10+1+1+1; block++)
                write3byte(sbi, (u8 *)&si->i_data[block],
                        &raw_inode->i_data[3*block]);
        mark_buffer_dirty(bh);
        return bh;
}

int sysv_write_inode(struct inode * inode, int wait)
{
        struct buffer_head *bh;
        lock_kernel();
        bh = sysv_update_inode(inode);
        brelse(bh);
        unlock_kernel();
        return 0;
}

int sysv_sync_inode(struct inode * inode)
{
        int err = 0;
        struct buffer_head *bh;

        bh = sysv_update_inode(inode);
        if (bh && buffer_dirty(bh)) {
                sync_dirty_buffer(bh);
                if (buffer_req(bh) && !buffer_uptodate(bh)) {
                        printk ("IO error syncing sysv inode [%s:%08lx]\n",
                                inode->i_sb->s_id, inode->i_ino);
                        err = -1;
                }
        }
        else if (!bh)
                err = -1;
        brelse (bh);
        return err;
}

static void sysv_delete_inode(struct inode *inode)
{
        truncate_inode_pages(&inode->i_data, 0);
        inode->i_size = 0;
        sysv_truncate(inode);
        lock_kernel();
        sysv_free_inode(inode);
        unlock_kernel();
}

static struct kmem_cache *sysv_inode_cachep;

static struct inode *sysv_alloc_inode(struct super_block *sb)
{
        struct sysv_inode_info *si;

        si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
        if (!si)
                return NULL;
        return &si->vfs_inode;
}

static void sysv_destroy_inode(struct inode *inode)
{
        kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
}

static void init_once(void *p)
{
        struct sysv_inode_info *si = (struct sysv_inode_info *)p;

        inode_init_once(&si->vfs_inode);
}

const struct super_operations sysv_sops = {
        .alloc_inode    = sysv_alloc_inode,
        .destroy_inode  = sysv_destroy_inode,
        .write_inode    = sysv_write_inode,
        .delete_inode   = sysv_delete_inode,
        .put_super      = sysv_put_super,
        .write_super    = sysv_write_super,
        .remount_fs     = sysv_remount,
        .statfs         = sysv_statfs,
};

int __init sysv_init_icache(void)
{
        sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
                        sizeof(struct sysv_inode_info), 0,
                        SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
                        init_once);
        if (!sysv_inode_cachep)
                return -ENOMEM;
        return 0;
}

void sysv_destroy_icache(void)
{
        kmem_cache_destroy(sysv_inode_cachep);
}

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