v2.6.22.24-op1

[linux-2.6.22.y-op.git] / fs / bfs / inode.c

/*
 *      fs/bfs/inode.c
 *      BFS superblock and inode operations.
 *      Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
 *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
 *
 *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
 */

#include <linux/module.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <asm/uaccess.h>
#include "bfs.h"

MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
MODULE_LICENSE("GPL");

#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;
        struct bfs_inode * di;
        struct buffer_head * bh;
        int block, off;

        if (ino < BFS_ROOT_INO || ino > BFS_SB(inode->i_sb)->si_lasti) {
                printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, 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", inode->i_sb->s_id, 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 &  le32_to_cpu(di->i_mode);
        if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
                inode->i_mode |= S_IFDIR;
                inode->i_op = &bfs_dir_inops;
                inode->i_fop = &bfs_dir_operations;
        } else if (le32_to_cpu(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;
        }

        BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
        BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
        inode->i_uid =  le32_to_cpu(di->i_uid);
        inode->i_gid =  le32_to_cpu(di->i_gid);
        inode->i_nlink =  le32_to_cpu(di->i_nlink);
        inode->i_size = BFS_FILESIZE(di);
        inode->i_blocks = BFS_FILEBLOCKS(di);
        if (inode->i_size || inode->i_blocks) dprintf("Registered inode with %lld size, %ld blocks\n", inode->i_size, inode->i_blocks);
        inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
        inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
        inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
        inode->i_atime.tv_nsec = 0;
        inode->i_mtime.tv_nsec = 0;
        inode->i_ctime.tv_nsec = 0;
        BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino); /* can be 0 so we store a copy */

        brelse(bh);
}

static int bfs_write_inode(struct inode * inode, int unused)
{
        unsigned int ino = (u16)inode->i_ino;
        unsigned long i_sblock;
        struct bfs_inode * di;
        struct buffer_head * bh;
        int block, off;

        dprintf("ino=%08x\n", ino);

        if (ino < BFS_ROOT_INO || ino > BFS_SB(inode->i_sb)->si_lasti) {
                printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
                return -EIO;
        }

        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:%08x\n", inode->i_sb->s_id, ino);
                unlock_kernel();
                return -EIO;
        }

        off = (ino - BFS_ROOT_INO)%BFS_INODES_PER_BLOCK;
        di = (struct bfs_inode *)bh->b_data + off;

        if (ino == BFS_ROOT_INO)
                di->i_vtype = cpu_to_le32(BFS_VDIR);
        else
                di->i_vtype = cpu_to_le32(BFS_VREG);

        di->i_ino = cpu_to_le16(ino);
        di->i_mode = cpu_to_le32(inode->i_mode);
        di->i_uid = cpu_to_le32(inode->i_uid);
        di->i_gid = cpu_to_le32(inode->i_gid);
        di->i_nlink = cpu_to_le32(inode->i_nlink);
        di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
        di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
        di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
        i_sblock = BFS_I(inode)->i_sblock;
        di->i_sblock = cpu_to_le32(i_sblock);
        di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
        di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);

        mark_buffer_dirty(bh);
        dprintf("Written ino=%d into %d:%d\n",le16_to_cpu(di->i_ino),block,off);
        brelse(bh);
        unlock_kernel();
        return 0;
}

static void bfs_delete_inode(struct inode * inode)
{
        unsigned long ino = inode->i_ino;
        struct bfs_inode * di;
        struct buffer_head * bh;
        int block, off;
        struct super_block * s = inode->i_sb;
        struct bfs_sb_info * info = BFS_SB(s);
        struct bfs_inode_info * bi = BFS_I(inode);

        dprintf("ino=%08lx\n", ino);

        truncate_inode_pages(&inode->i_data, 0);

        if (ino < BFS_ROOT_INO || ino > info->si_lasti) {
                printf("invalid ino=%08lx\n", ino);
                return;
        }
        
        inode->i_size = 0;
        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
        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", inode->i_sb->s_id, ino);
                unlock_kernel();
                return;
        }
        off = (ino - BFS_ROOT_INO)%BFS_INODES_PER_BLOCK;
        di = (struct bfs_inode *) bh->b_data + off;
        if (bi->i_dsk_ino) {
                info->si_freeb += 1 + bi->i_eblock - bi->i_sblock;
                info->si_freei++;
                clear_bit(ino, info->si_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 (info->si_lf_eblk == BFS_I(inode)->i_eblock) {
                info->si_lf_eblk = BFS_I(inode)->i_sblock - 1;
                mark_buffer_dirty(info->si_sbh);
        }
        unlock_kernel();
        clear_inode(inode);
}

static void bfs_put_super(struct super_block *s)
{
        struct bfs_sb_info *info = BFS_SB(s);
        brelse(info->si_sbh);
        kfree(info->si_imap);
        kfree(info);
        s->s_fs_info = NULL;
}

static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
        struct super_block *s = dentry->d_sb;
        struct bfs_sb_info *info = BFS_SB(s);
        u64 id = huge_encode_dev(s->s_bdev->bd_dev);
        buf->f_type = BFS_MAGIC;
        buf->f_bsize = s->s_blocksize;
        buf->f_blocks = info->si_blocks;
        buf->f_bfree = buf->f_bavail = info->si_freeb;
        buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
        buf->f_ffree = info->si_freei;
        buf->f_fsid.val[0] = (u32)id;
        buf->f_fsid.val[1] = (u32)(id >> 32);
        buf->f_namelen = BFS_NAMELEN;
        return 0;
}

static void bfs_write_super(struct super_block *s)
{
        lock_kernel();
        if (!(s->s_flags & MS_RDONLY))
                mark_buffer_dirty(BFS_SB(s)->si_sbh);
        s->s_dirt = 0;
        unlock_kernel();
}

static struct kmem_cache * bfs_inode_cachep;

static struct inode *bfs_alloc_inode(struct super_block *sb)
{
        struct bfs_inode_info *bi;
        bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
        if (!bi)
                return NULL;
        return &bi->vfs_inode;
}

static void bfs_destroy_inode(struct inode *inode)
{
        kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
}

static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
{
        struct bfs_inode_info *bi = foo;

        inode_init_once(&bi->vfs_inode);
}
 
static int init_inodecache(void)
{
        bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
                                             sizeof(struct bfs_inode_info),
                                             0, (SLAB_RECLAIM_ACCOUNT|
                                                SLAB_MEM_SPREAD),
                                             init_once, NULL);
        if (bfs_inode_cachep == NULL)
                return -ENOMEM;
        return 0;
}

static void destroy_inodecache(void)
{
        kmem_cache_destroy(bfs_inode_cachep);
}

static const struct super_operations bfs_sops = {
        .alloc_inode    = bfs_alloc_inode,
        .destroy_inode  = bfs_destroy_inode,
        .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)
{
#ifdef DEBUG
        int i;
        char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);

        if (!tmpbuf)
                return;
        for (i=BFS_SB(s)->si_lasti; i>=0; i--) {
                if (i > PAGE_SIZE-100) break;
                if (test_bit(i, BFS_SB(s)->si_imap))
                        strcat(tmpbuf, "1");
                else
                        strcat(tmpbuf, "0");
        }
        printk(KERN_ERR "BFS-fs: %s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
        free_page((unsigned long)tmpbuf);
#endif
}

static int bfs_fill_super(struct super_block *s, void *data, int silent)
{
        struct buffer_head * bh;
        struct bfs_super_block * bfs_sb;
        struct inode * inode;
        unsigned i, imap_len;
        struct bfs_sb_info * info;

        info = kzalloc(sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;
        s->s_fs_info = info;

        sb_set_blocksize(s, BFS_BSIZE);

        bh = sb_bread(s, 0);
        if(!bh)
                goto out;
        bfs_sb = (struct bfs_super_block *)bh->b_data;
        if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
                if (!silent)
                        printf("No BFS filesystem on %s (magic=%08x)\n", 
                                s->s_id,  le32_to_cpu(bfs_sb->s_magic));
                goto out;
        }
        if (BFS_UNCLEAN(bfs_sb, s) && !silent)
                printf("%s is unclean, continuing\n", s->s_id);

        s->s_magic = BFS_MAGIC;
        info->si_sbh = bh;
        info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE)/sizeof(struct bfs_inode)
                        + BFS_ROOT_INO - 1;

        imap_len = info->si_lasti/8 + 1;
        info->si_imap = kzalloc(imap_len, GFP_KERNEL);
        if (!info->si_imap)
                goto out;
        for (i=0; i<BFS_ROOT_INO; i++) 
                set_bit(i, info->si_imap);

        s->s_op = &bfs_sops;
        inode = iget(s, BFS_ROOT_INO);
        if (!inode) {
                kfree(info->si_imap);
                goto out;
        }
        s->s_root = d_alloc_root(inode);
        if (!s->s_root) {
                iput(inode);
                kfree(info->si_imap);
                goto out;
        }

        info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1)>>BFS_BSIZE_BITS; /* for statfs(2) */
        info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 -  le32_to_cpu(bfs_sb->s_start))>>BFS_BSIZE_BITS;
        info->si_freei = 0;
        info->si_lf_eblk = 0;
        info->si_lf_sblk = 0;
        info->si_lf_ioff = 0;
        bh = NULL;
        for (i=BFS_ROOT_INO; i<=info->si_lasti; i++) {
                struct bfs_inode *di;
                int block = (i - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;
                int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
                unsigned long sblock, eblock;

                if (!off) {
                        brelse(bh);
                        bh = sb_bread(s, block);
                }

                if (!bh)
                        continue;

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

                if (!di->i_ino) {
                        info->si_freei++;
                        continue;
                }
                set_bit(i, info->si_imap);
                info->si_freeb -= BFS_FILEBLOCKS(di);

                sblock =  le32_to_cpu(di->i_sblock);
                eblock =  le32_to_cpu(di->i_eblock);
                if (eblock > info->si_lf_eblk) {
                        info->si_lf_eblk = eblock;
                        info->si_lf_sblk = sblock;
                        info->si_lf_ioff = BFS_INO2OFF(i);
                }
        }
        brelse(bh);
        if (!(s->s_flags & MS_RDONLY)) {
                mark_buffer_dirty(info->si_sbh);
                s->s_dirt = 1;
        } 
        dump_imap("read_super", s);
        return 0;

out:
        brelse(bh);
        kfree(info);
        s->s_fs_info = NULL;
        return -EINVAL;
}

static int bfs_get_sb(struct file_system_type *fs_type,
        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
        return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
}

static struct file_system_type bfs_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "bfs",
        .get_sb         = bfs_get_sb,
        .kill_sb        = kill_block_super,
        .fs_flags       = FS_REQUIRES_DEV,
};

static int __init init_bfs_fs(void)
{
        int err = init_inodecache();
        if (err)
                goto out1;
        err = register_filesystem(&bfs_fs_type);
        if (err)
                goto out;
        return 0;
out:
        destroy_inodecache();
out1:
        return err;
}

static void __exit exit_bfs_fs(void)
{
        unregister_filesystem(&bfs_fs_type);
        destroy_inodecache();
}

module_init(init_bfs_fs)
module_exit(exit_bfs_fs)