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/*

 *  linux/fs/ext/inode.c

 *

 *  Copyright (C) 1992  Remy Card (card@masi.ibp.fr)

 *

 *  from

 *

 *  linux/fs/minix/inode.c

 *

 *  Copyright (C) 1991, 1992  Linus Torvalds

 */

#include <linux/module.h>

#include <linux/sched.h>

#include <linux/ext_fs.h>

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/string.h>

#include <linux/stat.h>

#include <linux/locks.h>

#include <asm/system.h>

#include <asm/segment.h>

void ext_put_inode(struct inode *inode)

{

        if (inode->i_nlink)

                return;

        inode->i_size = 0;

        ext_truncate(inode);

        ext_free_inode(inode);

}

void ext_put_super(struct super_block *sb)

{

        lock_super(sb);

        sb->s_dev = 0;

        if (sb->u.ext_sb.s_firstfreeinodeblock)

                brelse (sb->u.ext_sb.s_firstfreeinodeblock);

        if (sb->u.ext_sb.s_firstfreeblock)

                brelse (sb->u.ext_sb.s_firstfreeblock);

        unlock_super(sb);

        MOD_DEC_USE_COUNT;

        return;

}

static struct super_operations ext_sops = {

        ext_read_inode,

        NULL,

        ext_write_inode,

        ext_put_inode,

        ext_put_super,

        ext_write_super,

        ext_statfs,

        NULL

};

struct super_block *ext_read_super(struct super_block *s,void *data,

                                   int silent)

{

        struct buffer_head *bh;

        struct ext_super_block *es;

        kdev_t dev = s->s_dev;

        int block;

        MOD_INC_USE_COUNT;

        lock_super(s);

        set_blocksize(dev, BLOCK_SIZE);

        if (!(bh = bread(dev, 1, BLOCK_SIZE))) {

                s->s_dev = 0;

                unlock_super(s);

                printk("EXT-fs: unable to read superblock\n");

                MOD_DEC_USE_COUNT;

                return NULL;

        }

        es = (struct ext_super_block *) bh->b_data;

        s->s_blocksize = 1024;

        s->s_blocksize_bits = 10;

        s->u.ext_sb.s_ninodes = es->s_ninodes;

        s->u.ext_sb.s_nzones = es->s_nzones;

        s->u.ext_sb.s_firstdatazone = es->s_firstdatazone;

        s->u.ext_sb.s_log_zone_size = es->s_log_zone_size;

        s->u.ext_sb.s_max_size = es->s_max_size;

        s->s_magic = es->s_magic;

        s->u.ext_sb.s_firstfreeblocknumber = es->s_firstfreeblock;

        s->u.ext_sb.s_freeblockscount = es->s_freeblockscount;

        s->u.ext_sb.s_firstfreeinodenumber = es->s_firstfreeinode;

        s->u.ext_sb.s_freeinodescount = es->s_freeinodescount;

        brelse(bh);

        if (s->s_magic != EXT_SUPER_MAGIC) {

                s->s_dev = 0;

                unlock_super(s);

                if (!silent)

                        printk("VFS: Can't find an extfs filesystem on dev "

                               "%s.\n", kdevname(dev));

                MOD_DEC_USE_COUNT;

                return NULL;

        }

        if (!s->u.ext_sb.s_firstfreeblocknumber)

                s->u.ext_sb.s_firstfreeblock = NULL;

        else

                if (!(s->u.ext_sb.s_firstfreeblock = bread(dev,

                        s->u.ext_sb.s_firstfreeblocknumber, BLOCK_SIZE))) {

                        printk("ext_read_super: unable to read first free block\n");

                        s->s_dev = 0;

                        unlock_super(s);

                        MOD_DEC_USE_COUNT;

                        return NULL;

                }

        if (!s->u.ext_sb.s_firstfreeinodenumber)

                s->u.ext_sb.s_firstfreeinodeblock = NULL;

        else {

                block = 2 + (s->u.ext_sb.s_firstfreeinodenumber - 1) / EXT_INODES_PER_BLOCK;

                if (!(s->u.ext_sb.s_firstfreeinodeblock = bread(dev, block, BLOCK_SIZE))) {

                        printk("ext_read_super: unable to read first free inode block\n");

                        brelse(s->u.ext_sb.s_firstfreeblock);

                        s->s_dev = 0;

                        unlock_super (s);

                        MOD_DEC_USE_COUNT;

                        return NULL;

                }

        }

        unlock_super(s);

        /* set up enough so that it can read an inode */

        s->s_dev = dev;

        s->s_op = &ext_sops;

        if (!(s->s_mounted = iget(s,EXT_ROOT_INO))) {

                s->s_dev = 0;

                printk("EXT-fs: get root inode failed\n");

                MOD_DEC_USE_COUNT;

                return NULL;

        }

        return s;

}

void ext_write_super (struct super_block *sb)

{

        struct buffer_head * bh;

        struct ext_super_block * es;

        if (!(bh = bread(sb->s_dev, 1, BLOCK_SIZE))) {

                printk ("ext_write_super: bread failed\n");

                return;

        }

        es = (struct ext_super_block *) bh->b_data;

        es->s_firstfreeblock = sb->u.ext_sb.s_firstfreeblocknumber;

        es->s_freeblockscount = sb->u.ext_sb.s_freeblockscount;

        es->s_firstfreeinode = sb->u.ext_sb.s_firstfreeinodenumber;

        es->s_freeinodescount = sb->u.ext_sb.s_freeinodescount;

        mark_buffer_dirty(bh, 1);

        brelse (bh);

        sb->s_dirt = 0;

}

void ext_statfs (struct super_block *sb, struct statfs *buf, int bufsiz)

{

        struct statfs tmp;

        tmp.f_type = EXT_SUPER_MAGIC;

        tmp.f_bsize = 1024;

        tmp.f_blocks = sb->u.ext_sb.s_nzones << sb->u.ext_sb.s_log_zone_size;

        tmp.f_bfree = ext_count_free_blocks(sb);

        tmp.f_bavail = tmp.f_bfree;

        tmp.f_files = sb->u.ext_sb.s_ninodes;

        tmp.f_ffree = ext_count_free_inodes(sb);

        tmp.f_namelen = EXT_NAME_LEN;

        memcpy_tofs(buf, &tmp, bufsiz);

}

#define inode_bmap(inode,nr) ((inode)->u.ext_i.i_data[(nr)])

static inline int block_bmap(struct buffer_head * bh, int nr)

{

        int tmp;

        if (!bh)

                return 0;

        tmp = ((unsigned long *) bh->b_data)[nr];

        brelse(bh);

        return tmp;

}

int ext_bmap(struct inode * inode,int block)

{

        int i;

        if (block<0) {

                printk("ext_bmap: block<0");

                return 0;

        }

        if (block >= 9+256+256*256+256*256*256) {

                printk("ext_bmap: block>big");

                return 0;

        }

        if (block<9)

                return inode_bmap(inode,block);

        block -= 9;

        if (block<256) {

                i = inode_bmap(inode,9);

                if (!i)

                        return 0;

                return block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block);

        }

        block -= 256;

        if (block<256*256) {

                i = inode_bmap(inode,10);

                if (!i)

                        return 0;

                i = block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block>>8);

                if (!i)

                        return 0;

                return block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block & 255);

        }

        block -= 256*256;

        i = inode_bmap(inode,11);

        if (!i)

                return 0;

        i = block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block>>16);

        if (!i)

                return 0;

        i = block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),(block>>8) & 255);

        if (!i)

                return 0;

        return block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block & 255);

}

static struct buffer_head * inode_getblk(struct inode * inode, int nr, int create)

{

        int tmp;

        unsigned long * p;

        struct buffer_head * result;

        p = inode->u.ext_i.i_data + nr;

repeat:

        tmp = *p;

        if (tmp) {

                result = getblk(inode->i_dev, tmp, BLOCK_SIZE);

                if (tmp == *p)

                        return result;

                brelse(result);

                goto repeat;

        }

        if (!create)

                return NULL;

        tmp = ext_new_block(inode->i_sb);

        if (!tmp)

                return NULL;

        result = getblk(inode->i_dev, tmp, BLOCK_SIZE);

        if (*p) {

                ext_free_block(inode->i_sb,tmp);

                brelse(result);

                goto repeat;

        }

        *p = tmp;

        inode->i_ctime = CURRENT_TIME;

        inode->i_dirt = 1;

        return result;

}

static struct buffer_head * block_getblk(struct inode * inode,

        struct buffer_head * bh, int nr, int create)

{

        int tmp;

        unsigned long * p;

        struct buffer_head * result;

        if (!bh)

                return NULL;

        if (!buffer_uptodate(bh)) {

                ll_rw_block(READ, 1, &bh);

                wait_on_buffer(bh);

                if (!buffer_uptodate(bh)) {

                        brelse(bh);

                        return NULL;

                }

        }

        p = nr + (unsigned long *) bh->b_data;

repeat:

        tmp = *p;

        if (tmp) {

                result = getblk(bh->b_dev, tmp, BLOCK_SIZE);

                if (tmp == *p) {

                        brelse(bh);

                        return result;

                }

                brelse(result);

                goto repeat;

        }

        if (!create) {

                brelse(bh);

                return NULL;

        }

        tmp = ext_new_block(inode->i_sb);

        if (!tmp) {

                brelse(bh);

                return NULL;

        }

        result = getblk(bh->b_dev, tmp, BLOCK_SIZE);

        if (*p) {

                ext_free_block(inode->i_sb,tmp);

                brelse(result);

                goto repeat;

        }

        *p = tmp;

        mark_buffer_dirty(bh, 1);

        brelse(bh);

        return result;

}

struct buffer_head * ext_getblk(struct inode * inode, int block, int create)

{

        struct buffer_head * bh;

        if (block<0) {

                printk("ext_getblk: block<0\n");

                return NULL;

        }

        if (block >= 9+256+256*256+256*256*256) {

                printk("ext_getblk: block>big\n");

                return NULL;

        }

        if (block<9)

                return inode_getblk(inode,block,create);

        block -= 9;

        if (block<256) {

                bh = inode_getblk(inode,9,create);

                return block_getblk(inode,bh,block,create);

        }

        block -= 256;

        if (block<256*256) {

                bh = inode_getblk(inode,10,create);

                bh = block_getblk(inode,bh,block>>8,create);

                return block_getblk(inode,bh,block & 255,create);

        }

        block -= 256*256;

        bh = inode_getblk(inode,11,create);

        bh = block_getblk(inode,bh,block>>16,create);

        bh = block_getblk(inode,bh,(block>>8) & 255,create);

        return block_getblk(inode,bh,block & 255,create);

}

struct buffer_head * ext_bread(struct inode * inode, int block, int create)

{

        struct buffer_head * bh;

        bh = ext_getblk(inode,block,create);

        if (!bh || buffer_uptodate(bh))

                return bh;

        ll_rw_block(READ, 1, &bh);

        wait_on_buffer(bh);

        if (buffer_uptodate(bh))

                return bh;

        brelse(bh);

        return NULL;

}

void ext_read_inode(struct inode * inode)

{

        struct buffer_head * bh;

        struct ext_inode * raw_inode;

        int block;

        block = 2 + (inode->i_ino-1)/EXT_INODES_PER_BLOCK;

        if (!(bh=bread(inode->i_dev, block, BLOCK_SIZE)))

                panic("unable to read i-node block");

        raw_inode = ((struct ext_inode *) bh->b_data) +

                (inode->i_ino-1)%EXT_INODES_PER_BLOCK;

        inode->i_mode = raw_inode->i_mode;

        inode->i_uid = raw_inode->i_uid;

        inode->i_gid = raw_inode->i_gid;

        inode->i_nlink = raw_inode->i_nlinks;

        inode->i_size = raw_inode->i_size;

        inode->i_mtime = inode->i_atime = inode->i_ctime = raw_inode->i_time;

        inode->i_blocks = inode->i_blksize = 0;

        if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))

                inode->i_rdev = to_kdev_t(raw_inode->i_zone[0]);

        else for (block = 0; block < 12; block++)

                inode->u.ext_i.i_data[block] = raw_inode->i_zone[block];

        brelse(bh);

        inode->i_op = NULL;

        if (S_ISREG(inode->i_mode))

                inode->i_op = &ext_file_inode_operations;

        else if (S_ISDIR(inode->i_mode))

                inode->i_op = &ext_dir_inode_operations;

        else if (S_ISLNK(inode->i_mode))

                inode->i_op = &ext_symlink_inode_operations;

        else if (S_ISCHR(inode->i_mode))

                inode->i_op = &chrdev_inode_operations;

        else if (S_ISBLK(inode->i_mode))

                inode->i_op = &blkdev_inode_operations;

        else if (S_ISFIFO(inode->i_mode))

                init_fifo(inode);

}

static struct buffer_head * ext_update_inode(struct inode * inode)

{

        struct buffer_head * bh;

        struct ext_inode * raw_inode;

        int block;

        block = 2 + (inode->i_ino-1)/EXT_INODES_PER_BLOCK;

        if (!(bh=bread(inode->i_dev, block, BLOCK_SIZE)))

                panic("unable to read i-node block");

        raw_inode = ((struct ext_inode *)bh->b_data) +

                (inode->i_ino-1)%EXT_INODES_PER_BLOCK;

        raw_inode->i_mode = inode->i_mode;

        raw_inode->i_uid = inode->i_uid;

        raw_inode->i_gid = inode->i_gid;

        raw_inode->i_nlinks = inode->i_nlink;

        raw_inode->i_size = inode->i_size;

        raw_inode->i_time = inode->i_mtime;

        if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))

                raw_inode->i_zone[0] = kdev_t_to_nr(inode->i_rdev);

        else for (block = 0; block < 12; block++)

                raw_inode->i_zone[block] = inode->u.ext_i.i_data[block];

        mark_buffer_dirty(bh, 1);

        inode->i_dirt=0;

        return bh;

}

void ext_write_inode(struct inode * inode)

{

        struct buffer_head *bh;

        bh = ext_update_inode (inode);

        brelse(bh);

}

int ext_sync_inode (struct inode *inode)

{

        int err = 0;

        struct buffer_head *bh;

        bh = ext_update_inode(inode);

        if (bh && buffer_dirty(bh))

        {

                ll_rw_block(WRITE, 1, &bh);

                wait_on_buffer(bh);

                if (buffer_req(bh) && !buffer_uptodate(bh))

                {

                        printk ("IO error syncing ext inode ["

                                "%s:%08lx]\n",

                                kdevname(inode->i_dev), inode->i_ino);

                        err = -1;

                }

        }

        else if (!bh)

                err = -1;

        brelse (bh);

        return err;

}

static struct file_system_type ext_fs_type = {

        ext_read_super, "ext", 1, NULL

};

int init_ext_fs(void)

{

        return register_filesystem(&ext_fs_type);

}

#ifdef MODULE

int init_module(void)

{

        int status;

        if ((status = init_ext_fs()) == 0)

                register_symtab(0);

        return status;

}

void cleanup_module(void)

{

        unregister_filesystem(&ext_fs_type);

}

#endif