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/*

 *      fs/bfs/inode.c

 *      BFS superblock and inode operations.

 *      Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>

 *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.

 */

#include <linux/module.h>

#include <linux/mm.h>

#include <linux/slab.h>

#include <linux/init.h>

#include <linux/locks.h>

#include <linux/bfs_fs.h>

#include <linux/smp_lock.h>

#include <asm/uaccess.h>

#include "bfs_defs.h"

MODULE_AUTHOR("Tigran A. Aivazian <tigran@veritas.com>");

MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");

MODULE_LICENSE("GPL");

EXPORT_NO_SYMBOLS;

#undef DEBUG

#ifdef DEBUG

#define dprintf(x...)   printf(x)

#else

#define dprintf(x...)

#endif

void dump_imap(const char *prefix, struct super_block * s);

static void bfs_read_inode(struct inode * inode)

{

        unsigned long ino = inode->i_ino;

        kdev_t dev = inode->i_dev;

        struct bfs_inode * di;

        struct buffer_head * bh;

        int block, off;

        if (ino < BFS_ROOT_INO || ino > inode->i_sb->su_lasti) {

                printf("Bad inode number %s:%08lx\n", bdevname(dev), ino);

                make_bad_inode(inode);

                return;

        }

        block = (ino - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;

        bh = sb_bread(inode->i_sb, block);

        if (!bh) {

                printf("Unable to read inode %s:%08lx\n", bdevname(dev), ino);

                make_bad_inode(inode);

                return;

        }

        off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;

        di = (struct bfs_inode *)bh->b_data + off;

        inode->i_mode = 0x0000FFFF & di->i_mode;

        if (di->i_vtype == BFS_VDIR) {

                inode->i_mode |= S_IFDIR;

                inode->i_op = &bfs_dir_inops;

                inode->i_fop = &bfs_dir_operations;

        } else if (di->i_vtype == BFS_VREG) {

                inode->i_mode |= S_IFREG;

                inode->i_op = &bfs_file_inops;

                inode->i_fop = &bfs_file_operations;

                inode->i_mapping->a_ops = &bfs_aops;

        }

        inode->i_uid = di->i_uid;

        inode->i_gid = di->i_gid;

        inode->i_nlink = di->i_nlink;

        inode->i_size = BFS_FILESIZE(di);

        inode->i_blocks = BFS_FILEBLOCKS(di);

        inode->i_blksize = PAGE_SIZE;

        inode->i_atime = di->i_atime;

        inode->i_mtime = di->i_mtime;

        inode->i_ctime = di->i_ctime;

        inode->iu_dsk_ino = di->i_ino; /* can be 0 so we store a copy */

        inode->iu_sblock = di->i_sblock;

        inode->iu_eblock = di->i_eblock;

        brelse(bh);

}

static void bfs_write_inode(struct inode * inode, int unused)

{

        unsigned long ino = inode->i_ino;

        kdev_t dev = inode->i_dev;

        struct bfs_inode * di;

        struct buffer_head * bh;

        int block, off;

        if (ino < BFS_ROOT_INO || ino > inode->i_sb->su_lasti) {

                printf("Bad inode number %s:%08lx\n", bdevname(dev), ino);

                return;

        }

        lock_kernel();

        block = (ino - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;

        bh = sb_bread(inode->i_sb, block);

        if (!bh) {

                printf("Unable to read inode %s:%08lx\n", bdevname(dev), ino);

                unlock_kernel();

                return;

        }

        off = (ino - BFS_ROOT_INO)%BFS_INODES_PER_BLOCK;

        di = (struct bfs_inode *)bh->b_data + off;

        if (inode->i_ino == BFS_ROOT_INO)

                di->i_vtype = BFS_VDIR;

        else

                di->i_vtype = BFS_VREG;

        di->i_ino = inode->i_ino;

        di->i_mode = inode->i_mode;

        di->i_uid = inode->i_uid;

        di->i_gid = inode->i_gid;

        di->i_nlink = inode->i_nlink;

        di->i_atime = inode->i_atime;

        di->i_mtime = inode->i_mtime;

        di->i_ctime = inode->i_ctime;

        di->i_sblock = inode->iu_sblock;

        di->i_eblock = inode->iu_eblock;

        di->i_eoffset = di->i_sblock * BFS_BSIZE + inode->i_size - 1;

        mark_buffer_dirty(bh);

        brelse(bh);

        unlock_kernel();

}

static void bfs_delete_inode(struct inode * inode)

{

        unsigned long ino = inode->i_ino;

        kdev_t dev = inode->i_dev;

        struct bfs_inode * di;

        struct buffer_head * bh;

        int block, off;

        struct super_block * s = inode->i_sb;

        dprintf("ino=%08lx\n", inode->i_ino);

        if (inode->i_ino < BFS_ROOT_INO || inode->i_ino > inode->i_sb->su_lasti) {

                printf("invalid ino=%08lx\n", inode->i_ino);

                return;

        }

        inode->i_size = 0;

        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;

        lock_kernel();

        mark_inode_dirty(inode);

        block = (ino - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;

        bh = sb_bread(s, block);

        if (!bh) {

                printf("Unable to read inode %s:%08lx\n", bdevname(dev), ino);

                unlock_kernel();

                return;

        }

        off = (ino - BFS_ROOT_INO)%BFS_INODES_PER_BLOCK;

        di = (struct bfs_inode *)bh->b_data + off;

        if (di->i_ino) {

                s->su_freeb += BFS_FILEBLOCKS(di);

                s->su_freei++;

                clear_bit(di->i_ino, s->su_imap);

                dump_imap("delete_inode", s);

        }

        di->i_ino = 0;

        di->i_sblock = 0;

        mark_buffer_dirty(bh);

        brelse(bh);

        /* if this was the last file, make the previous

           block "last files last block" even if there is no real file there,

           saves us 1 gap */

        if (s->su_lf_eblk == inode->iu_eblock) {

                s->su_lf_eblk = inode->iu_sblock - 1;

                mark_buffer_dirty(s->su_sbh);

        }

        unlock_kernel();

        clear_inode(inode);

}

static void bfs_put_super(struct super_block *s)

{

        brelse(s->su_sbh);

        kfree(s->su_imap);

}

static int bfs_statfs(struct super_block *s, struct statfs *buf)

{

        buf->f_type = BFS_MAGIC;

        buf->f_bsize = s->s_blocksize;

        buf->f_blocks = s->su_blocks;

        buf->f_bfree = buf->f_bavail = s->su_freeb;

        buf->f_files = s->su_lasti + 1 - BFS_ROOT_INO;

        buf->f_ffree = s->su_freei;

        buf->f_fsid.val[0] = kdev_t_to_nr(s->s_dev);

        buf->f_namelen = BFS_NAMELEN;

        return 0;

}

static void bfs_write_super(struct super_block *s)

{

        if (!(s->s_flags & MS_RDONLY))

                mark_buffer_dirty(s->su_sbh);

        s->s_dirt = 0;

}

static struct super_operations bfs_sops = {

        read_inode:     bfs_read_inode,

        write_inode:    bfs_write_inode,

        delete_inode:   bfs_delete_inode,

        put_super:      bfs_put_super,

        write_super:    bfs_write_super,

        statfs:         bfs_statfs,

};

void dump_imap(const char *prefix, struct super_block * s)

{

#if 0

        int i;

        char *tmpbuf = (char *)get_free_page(GFP_KERNEL);

        if (!tmpbuf)

                return;

        for (i=s->su_lasti; i>=0; i--) {

                if (i>PAGE_SIZE-100) break;

                if (test_bit(i, s->su_imap))

                        strcat(tmpbuf, "1");

                else

                        strcat(tmpbuf, "0");

        }

        printk(KERN_ERR "BFS-fs: %s: lasti=%08lx <%s>\n", prefix, s->su_lasti, tmpbuf);

        free_page((unsigned long)tmpbuf);

#endif

}

static struct super_block * bfs_read_super(struct super_block * s,

        void * data, int silent)

{

        kdev_t dev;

        struct buffer_head * bh;

        struct bfs_super_block * bfs_sb;

        struct inode * inode;

        int i, imap_len;

        dev = s->s_dev;

        set_blocksize(dev, BFS_BSIZE);

        s->s_blocksize = BFS_BSIZE;

        s->s_blocksize_bits = BFS_BSIZE_BITS;

        bh = sb_bread(s, 0);

        if(!bh)

                goto out;

        bfs_sb = (struct bfs_super_block *)bh->b_data;

        if (bfs_sb->s_magic != BFS_MAGIC) {

                if (!silent)

                        printf("No BFS filesystem on %s (magic=%08x)\n",

                                bdevname(dev), bfs_sb->s_magic);

                goto out;

        }

        if (BFS_UNCLEAN(bfs_sb, s) && !silent)

                printf("%s is unclean, continuing\n", bdevname(dev));

        s->s_magic = BFS_MAGIC;

        s->su_bfs_sb = bfs_sb;

        s->su_sbh = bh;

        s->su_lasti = (bfs_sb->s_start - BFS_BSIZE)/sizeof(struct bfs_inode)

                        + BFS_ROOT_INO - 1;

        imap_len = s->su_lasti/8 + 1;

        s->su_imap = kmalloc(imap_len, GFP_KERNEL);

        if (!s->su_imap)

                goto out;

        memset(s->su_imap, 0, imap_len);

        for (i=0; i<BFS_ROOT_INO; i++)

                set_bit(i, s->su_imap);

        s->s_op = &bfs_sops;

        inode = iget(s, BFS_ROOT_INO);

        if (!inode) {

                kfree(s->su_imap);

                goto out;

        }

        s->s_root = d_alloc_root(inode);

        if (!s->s_root) {

                iput(inode);

                kfree(s->su_imap);

                goto out;

        }

        s->su_blocks = (bfs_sb->s_end + 1)>>BFS_BSIZE_BITS; /* for statfs(2) */

        s->su_freeb = (bfs_sb->s_end + 1 - bfs_sb->s_start)>>BFS_BSIZE_BITS;

        s->su_freei = 0;

        s->su_lf_eblk = 0;

        s->su_lf_sblk = 0;

        s->su_lf_ioff = 0;

        for (i=BFS_ROOT_INO; i<=s->su_lasti; i++) {

                inode = iget(s,i);

                if (inode->iu_dsk_ino == 0)

                        s->su_freei++;

                else {

                        set_bit(i, s->su_imap);

                        s->su_freeb -= inode->i_blocks;

                        if (inode->iu_eblock > s->su_lf_eblk) {

                                s->su_lf_eblk = inode->iu_eblock;

                                s->su_lf_sblk = inode->iu_sblock;

                                s->su_lf_ioff = BFS_INO2OFF(i);

                        }

                }

                iput(inode);

        }

        if (!(s->s_flags & MS_RDONLY)) {

                mark_buffer_dirty(bh);

                s->s_dirt = 1;

        }

        dump_imap("read_super", s);

        return s;

out:

        brelse(bh);

        return NULL;

}

static DECLARE_FSTYPE_DEV(bfs_fs_type, "bfs", bfs_read_super);

static int __init init_bfs_fs(void)

{

        return register_filesystem(&bfs_fs_type);

}

static void __exit exit_bfs_fs(void)

{

        unregister_filesystem(&bfs_fs_type);

}

module_init(init_bfs_fs)

module_exit(exit_bfs_fs)