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/*

 *  linux/fs/affs/inode.c

 *

 *  (c) 1996  Hans-Joachim Widmaier - Rewritten

 *

 *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.

 *

 *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.

 *

 *  (C) 1991  Linus Torvalds - minix filesystem

 */

#include <linux/module.h>

#include <linux/init.h>

#include <linux/statfs.h>

#include <linux/parser.h>

#include <linux/magic.h>

#include <linux/sched.h>

#include "affs.h"

extern struct timezone sys_tz;

static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);

static int affs_remount (struct super_block *sb, int *flags, char *data);

static void

affs_put_super(struct super_block *sb)

{

        struct affs_sb_info *sbi = AFFS_SB(sb);

        pr_debug("AFFS: put_super()\n");

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

                AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);

                secs_to_datestamp(get_seconds(),

                                  &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);

                affs_fix_checksum(sb, sbi->s_root_bh);

                mark_buffer_dirty(sbi->s_root_bh);

        }

        kfree(sbi->s_prefix);

        affs_free_bitmap(sb);

        affs_brelse(sbi->s_root_bh);

        kfree(sbi);

        sb->s_fs_info = NULL;

        return;

}

static void

affs_write_super(struct super_block *sb)

{

        int clean = 2;

        struct affs_sb_info *sbi = AFFS_SB(sb);

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

                //      if (sbi->s_bitmap[i].bm_bh) {

                //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {

                //                      clean = 0;

                AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);

                secs_to_datestamp(get_seconds(),

                                  &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);

                affs_fix_checksum(sb, sbi->s_root_bh);

                mark_buffer_dirty(sbi->s_root_bh);

                sb->s_dirt = !clean;    /* redo until bitmap synced */

        } else

                sb->s_dirt = 0;

        pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);

}

static struct kmem_cache * affs_inode_cachep;

static struct inode *affs_alloc_inode(struct super_block *sb)

{

        struct affs_inode_info *ei;

        ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);

        if (!ei)

                return NULL;

        ei->vfs_inode.i_version = 1;

        return &ei->vfs_inode;

}

static void affs_destroy_inode(struct inode *inode)

{

        kmem_cache_free(affs_inode_cachep, AFFS_I(inode));

}

static void init_once(struct kmem_cache *cachep, void *foo)

{

        struct affs_inode_info *ei = (struct affs_inode_info *) foo;

        init_MUTEX(&ei->i_link_lock);

        init_MUTEX(&ei->i_ext_lock);

        inode_init_once(&ei->vfs_inode);

}

static int init_inodecache(void)

{

        affs_inode_cachep = kmem_cache_create("affs_inode_cache",

                                             sizeof(struct affs_inode_info),

                                             0, (SLAB_RECLAIM_ACCOUNT|

                                                SLAB_MEM_SPREAD),

                                             init_once);

        if (affs_inode_cachep == NULL)

                return -ENOMEM;

        return 0;

}

static void destroy_inodecache(void)

{

        kmem_cache_destroy(affs_inode_cachep);

}

static const struct super_operations affs_sops = {

        .alloc_inode    = affs_alloc_inode,

        .destroy_inode  = affs_destroy_inode,

        .read_inode     = affs_read_inode,

        .write_inode    = affs_write_inode,

        .put_inode      = affs_put_inode,

        .drop_inode     = affs_drop_inode,

        .delete_inode   = affs_delete_inode,

        .clear_inode    = affs_clear_inode,

        .put_super      = affs_put_super,

        .write_super    = affs_write_super,

        .statfs         = affs_statfs,

        .remount_fs     = affs_remount,

};

enum {

        Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,

        Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,

        Opt_verbose, Opt_volume, Opt_ignore, Opt_err,

};

static match_table_t tokens = {

        {Opt_bs, "bs=%u"},

        {Opt_mode, "mode=%o"},

        {Opt_mufs, "mufs"},

        {Opt_prefix, "prefix=%s"},

        {Opt_protect, "protect"},

        {Opt_reserved, "reserved=%u"},

        {Opt_root, "root=%u"},

        {Opt_setgid, "setgid=%u"},

        {Opt_setuid, "setuid=%u"},

        {Opt_verbose, "verbose"},

        {Opt_volume, "volume=%s"},

        {Opt_ignore, "grpquota"},

        {Opt_ignore, "noquota"},

        {Opt_ignore, "quota"},

        {Opt_ignore, "usrquota"},

        {Opt_err, NULL},

};

static int

parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,

                int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)

{

        char *p;

        substring_t args[MAX_OPT_ARGS];

        /* Fill in defaults */

        *uid        = current->uid;

        *gid        = current->gid;

        *reserved   = 2;

        *root       = -1;

        *blocksize  = -1;

        volume[0]   = ':';

        volume[1]   = 0;

        *mount_opts = 0;

        if (!options)

                return 1;

        while ((p = strsep(&options, ",")) != NULL) {

                int token, n, option;

                if (!*p)

                        continue;

                token = match_token(p, tokens, args);

                switch (token) {

                case Opt_bs:

                        if (match_int(&args[0], &n))

                                return -EINVAL;

                        if (n != 512 && n != 1024 && n != 2048

                            && n != 4096) {

                                printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");

                                return 0;

                        }

                        *blocksize = n;

                        break;

                case Opt_mode:

                        if (match_octal(&args[0], &option))

                                return 1;

                        *mode = option & 0777;

                        *mount_opts |= SF_SETMODE;

                        break;

                case Opt_mufs:

                        *mount_opts |= SF_MUFS;

                        break;

                case Opt_prefix:

                        /* Free any previous prefix */

                        kfree(*prefix);

                        *prefix = NULL;

                        *prefix = match_strdup(&args[0]);

                        if (!*prefix)

                                return 0;

                        *mount_opts |= SF_PREFIX;

                        break;

                case Opt_protect:

                        *mount_opts |= SF_IMMUTABLE;

                        break;

                case Opt_reserved:

                        if (match_int(&args[0], reserved))

                                return 1;

                        break;

                case Opt_root:

                        if (match_int(&args[0], root))

                                return 1;

                        break;

                case Opt_setgid:

                        if (match_int(&args[0], &option))

                                return 1;

                        *gid = option;

                        *mount_opts |= SF_SETGID;

                        break;

                case Opt_setuid:

                        if (match_int(&args[0], &option))

                                return -EINVAL;

                        *uid = option;

                        *mount_opts |= SF_SETUID;

                        break;

                case Opt_verbose:

                        *mount_opts |= SF_VERBOSE;

                        break;

                case Opt_volume: {

                        char *vol = match_strdup(&args[0]);

                        strlcpy(volume, vol, 32);

                        kfree(vol);

                        break;

                }

                case Opt_ignore:

                        /* Silently ignore the quota options */

                        break;

                default:

                        printk("AFFS: Unrecognized mount option \"%s\" "

                                        "or missing value\n", p);

                        return 0;

                }

        }

        return 1;

}

/* This function definitely needs to be split up. Some fine day I'll

 * hopefully have the guts to do so. Until then: sorry for the mess.

 */

static int affs_fill_super(struct super_block *sb, void *data, int silent)

{

        struct affs_sb_info     *sbi;

        struct buffer_head      *root_bh = NULL;

        struct buffer_head      *boot_bh;

        struct inode            *root_inode = NULL;

        s32                      root_block;

        int                      size, blocksize;

        u32                      chksum;

        int                      num_bm;

        int                      i, j;

        s32                      key;

        uid_t                    uid;

        gid_t                    gid;

        int                      reserved;

        unsigned long            mount_flags;

        int                      tmp_flags;     /* fix remount prototype... */

        u8                       sig[4];

        pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");

        sb->s_magic             = AFFS_SUPER_MAGIC;

        sb->s_op                = &affs_sops;

        sb->s_flags |= MS_NODIRATIME;

        sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);

        if (!sbi)

                return -ENOMEM;

        sb->s_fs_info = sbi;

        init_MUTEX(&sbi->s_bmlock);

        if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,

                                &blocksize,&sbi->s_prefix,

                                sbi->s_volume, &mount_flags)) {

                printk(KERN_ERR "AFFS: Error parsing options\n");

                return -EINVAL;

        }

        /* N.B. after this point s_prefix must be released */

        sbi->s_flags   = mount_flags;

        sbi->s_mode    = i;

        sbi->s_uid     = uid;

        sbi->s_gid     = gid;

        sbi->s_reserved= reserved;

        /* Get the size of the device in 512-byte blocks.

         * If we later see that the partition uses bigger

         * blocks, we will have to change it.

         */

        size = sb->s_bdev->bd_inode->i_size >> 9;

        pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);

        affs_set_blocksize(sb, PAGE_SIZE);

        /* Try to find root block. Its location depends on the block size. */

        i = 512;

        j = 4096;

        if (blocksize > 0) {

                i = j = blocksize;

                size = size / (blocksize / 512);

        }

        for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {

                sbi->s_root_block = root_block;

                if (root_block < 0)

                        sbi->s_root_block = (reserved + size - 1) / 2;

                pr_debug("AFFS: setting blocksize to %d\n", blocksize);

                affs_set_blocksize(sb, blocksize);

                sbi->s_partition_size = size;

                /* The root block location that was calculated above is not

                 * correct if the partition size is an odd number of 512-

                 * byte blocks, which will be rounded down to a number of

                 * 1024-byte blocks, and if there were an even number of

                 * reserved blocks. Ideally, all partition checkers should

                 * report the real number of blocks of the real blocksize,

                 * but since this just cannot be done, we have to try to

                 * find the root block anyways. In the above case, it is one

                 * block behind the calculated one. So we check this one, too.

                 */

                for (num_bm = 0; num_bm < 2; num_bm++) {

                        pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "

                                "size=%d, reserved=%d\n",

                                sb->s_id,

                                sbi->s_root_block + num_bm,

                                blocksize, size, reserved);

                        root_bh = affs_bread(sb, sbi->s_root_block + num_bm);

                        if (!root_bh)

                                continue;

                        if (!affs_checksum_block(sb, root_bh) &&

                            be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&

                            be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {

                                sbi->s_hashsize    = blocksize / 4 - 56;

                                sbi->s_root_block += num_bm;

                                key                        = 1;

                                goto got_root;

                        }

                        affs_brelse(root_bh);

                        root_bh = NULL;

                }

        }

        if (!silent)

                printk(KERN_ERR "AFFS: No valid root block on device %s\n",

                        sb->s_id);

        goto out_error;

        /* N.B. after this point bh must be released */

got_root:

        root_block = sbi->s_root_block;

        /* Find out which kind of FS we have */

        boot_bh = sb_bread(sb, 0);

        if (!boot_bh) {

                printk(KERN_ERR "AFFS: Cannot read boot block\n");

                goto out_error;

        }

        memcpy(sig, boot_bh->b_data, 4);

        brelse(boot_bh);

        chksum = be32_to_cpu(*(__be32 *)sig);

        /* Dircache filesystems are compatible with non-dircache ones

         * when reading. As long as they aren't supported, writing is

         * not recommended.

         */

        if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS

             || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {

                printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",

                        sb->s_id);

                sb->s_flags |= MS_RDONLY;

        }

        switch (chksum) {

                case MUFS_FS:

                case MUFS_INTLFFS:

                case MUFS_DCFFS:

                        sbi->s_flags |= SF_MUFS;

                        /* fall thru */

                case FS_INTLFFS:

                case FS_DCFFS:

                        sbi->s_flags |= SF_INTL;

                        break;

                case MUFS_FFS:

                        sbi->s_flags |= SF_MUFS;

                        break;

                case FS_FFS:

                        break;

                case MUFS_OFS:

                        sbi->s_flags |= SF_MUFS;

                        /* fall thru */

                case FS_OFS:

                        sbi->s_flags |= SF_OFS;

                        sb->s_flags |= MS_NOEXEC;

                        break;

                case MUFS_DCOFS:

                case MUFS_INTLOFS:

                        sbi->s_flags |= SF_MUFS;

                case FS_DCOFS:

                case FS_INTLOFS:

                        sbi->s_flags |= SF_INTL | SF_OFS;

                        sb->s_flags |= MS_NOEXEC;

                        break;

                default:

                        printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",

                                sb->s_id, chksum);

                        goto out_error;

        }

        if (mount_flags & SF_VERBOSE) {

                u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];

                printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",

                        len > 31 ? 31 : len,

                        AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,

                        sig, sig[3] + '0', blocksize);

        }

        sb->s_flags |= MS_NODEV | MS_NOSUID;

        sbi->s_data_blksize = sb->s_blocksize;

        if (sbi->s_flags & SF_OFS)

                sbi->s_data_blksize -= 24;

        /* Keep super block in cache */

        sbi->s_root_bh = root_bh;

        /* N.B. after this point s_root_bh must be released */

        tmp_flags = sb->s_flags;

        if (affs_init_bitmap(sb, &tmp_flags))

                goto out_error;

        sb->s_flags = tmp_flags;

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

        root_inode = iget(sb, root_block);

        sb->s_root = d_alloc_root(root_inode);

        if (!sb->s_root) {

                printk(KERN_ERR "AFFS: Get root inode failed\n");

                goto out_error;

        }

        sb->s_root->d_op = &affs_dentry_operations;

        pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);

        return 0;

        /*

         * Begin the cascaded cleanup ...

         */

out_error:

        if (root_inode)

                iput(root_inode);

        kfree(sbi->s_bitmap);

        affs_brelse(root_bh);

        kfree(sbi->s_prefix);

        kfree(sbi);

        sb->s_fs_info = NULL;

        return -EINVAL;

}

static int

affs_remount(struct super_block *sb, int *flags, char *data)

{

        struct affs_sb_info     *sbi = AFFS_SB(sb);

        int                      blocksize;

        uid_t                    uid;

        gid_t                    gid;

        int                      mode;

        int                      reserved;

        int                      root_block;

        unsigned long            mount_flags;

        int                      res = 0;

        pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);

        *flags |= MS_NODIRATIME;

        if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,

            &blocksize,&sbi->s_prefix,sbi->s_volume,&mount_flags))

                return -EINVAL;

        sbi->s_flags = mount_flags;

        sbi->s_mode  = mode;

        sbi->s_uid   = uid;

        sbi->s_gid   = gid;

        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))

                return 0;

        if (*flags & MS_RDONLY) {

                sb->s_dirt = 1;

                while (sb->s_dirt)

                        affs_write_super(sb);

                affs_free_bitmap(sb);

        } else

                res = affs_init_bitmap(sb, flags);

        return res;

}

static int

affs_statfs(struct dentry *dentry, struct kstatfs *buf)

{

        struct super_block *sb = dentry->d_sb;

        int              free;

        pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,

             AFFS_SB(sb)->s_reserved);

        free          = affs_count_free_blocks(sb);

        buf->f_type    = AFFS_SUPER_MAGIC;

        buf->f_bsize   = sb->s_blocksize;

        buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;

        buf->f_bfree   = free;

        buf->f_bavail  = free;

        return 0;

}

static int affs_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, affs_fill_super,

                           mnt);

}

static struct file_system_type affs_fs_type = {

        .owner          = THIS_MODULE,

        .name           = "affs",

        .get_sb         = affs_get_sb,

        .kill_sb        = kill_block_super,

        .fs_flags       = FS_REQUIRES_DEV,

};

static int __init init_affs_fs(void)

{

        int err = init_inodecache();

        if (err)

                goto out1;

        err = register_filesystem(&affs_fs_type);

        if (err)

                goto out;

        return 0;

out:

        destroy_inodecache();

out1:

        return err;

}

static void __exit exit_affs_fs(void)

{

        unregister_filesystem(&affs_fs_type);

        destroy_inodecache();

}

MODULE_DESCRIPTION("Amiga filesystem support for Linux");

MODULE_LICENSE("GPL");

module_init(init_affs_fs)

module_exit(exit_affs_fs)