/*
 *  linux/fs/hfs/super.c
 *
 * Copyright (C) 1995-1997  Paul H. Hargrove
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 * This file may be distributed under the terms of the GNU General Public License.
 *
 * This file contains hfs_read_super(), some of the super_ops and
 * init_hfs_fs() and exit_hfs_fs().  The remaining super_ops are in
 * inode.c since they deal with inodes.
 *
 * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
 */

#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/nls.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/vfs.h>

#include "hfs_fs.h"
#include "btree.h"

static struct kmem_cache *hfs_inode_cachep;

MODULE_DESCRIPTION("Apple Macintosh file system support");
MODULE_LICENSE("GPL");

static int hfs_sync_fs(struct super_block *sb, int wait)
{
        is_hfs_cnid_counts_valid(sb);
        hfs_mdb_commit(sb);
        return 0;
}

/*
 * hfs_put_super()
 *
 * This is the put_super() entry in the super_operations structure for
 * HFS filesystems.  The purpose is to release the resources
 * associated with the superblock sb.
 */
static void hfs_put_super(struct super_block *sb)
{
        cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
        hfs_mdb_close(sb);
        /* release the MDB's resources */
        hfs_mdb_put(sb);
}

static void flush_mdb(struct work_struct *work)
{
        struct hfs_sb_info *sbi;
        struct super_block *sb;

        sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
        sb = sbi->sb;

        spin_lock(&sbi->work_lock);
        sbi->work_queued = 0;
        spin_unlock(&sbi->work_lock);

        is_hfs_cnid_counts_valid(sb);

        hfs_mdb_commit(sb);
}

void hfs_mark_mdb_dirty(struct super_block *sb)
{
        struct hfs_sb_info *sbi = HFS_SB(sb);
        unsigned long delay;

        if (sb_rdonly(sb))
                return;

        spin_lock(&sbi->work_lock);
        if (!sbi->work_queued) {
                delay = msecs_to_jiffies(dirty_writeback_interval * 10);
                queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
                sbi->work_queued = 1;
        }
        spin_unlock(&sbi->work_lock);
}

/*
 * hfs_statfs()
 *
 * This is the statfs() entry in the super_operations structure for
 * HFS filesystems.  The purpose is to return various data about the
 * filesystem.
 *
 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
 */
static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
        struct super_block *sb = dentry->d_sb;
        u64 id = huge_encode_dev(sb->s_bdev->bd_dev);

        buf->f_type = HFS_SUPER_MAGIC;
        buf->f_bsize = sb->s_blocksize;
        buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
        buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
        buf->f_bavail = buf->f_bfree;
        buf->f_files = HFS_SB(sb)->fs_ablocks;
        buf->f_ffree = HFS_SB(sb)->free_ablocks;
        buf->f_fsid = u64_to_fsid(id);
        buf->f_namelen = HFS_NAMELEN;

        return 0;
}

static int hfs_reconfigure(struct fs_context *fc)
{
        struct super_block *sb = fc->root->d_sb;

        sync_filesystem(sb);
        fc->sb_flags |= SB_NODIRATIME;
        if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
                return 0;

        if (!(fc->sb_flags & SB_RDONLY)) {
                if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
                        pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
                        sb->s_flags |= SB_RDONLY;
                        fc->sb_flags |= SB_RDONLY;
                } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
                        pr_warn("filesystem is marked locked, leaving read-only.\n");
                        sb->s_flags |= SB_RDONLY;
                        fc->sb_flags |= SB_RDONLY;
                }
        }
        return 0;
}

static int hfs_show_options(struct seq_file *seq, struct dentry *root)
{
        struct hfs_sb_info *sbi = HFS_SB(root->d_sb);

        if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
                seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
        if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
                seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
        seq_printf(seq, ",uid=%u,gid=%u",
                        from_kuid_munged(&init_user_ns, sbi->s_uid),
                        from_kgid_munged(&init_user_ns, sbi->s_gid));
        if (sbi->s_file_umask != 0133)
                seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
        if (sbi->s_dir_umask != 0022)
                seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
        if (sbi->part >= 0)
                seq_printf(seq, ",part=%u", sbi->part);
        if (sbi->session >= 0)
                seq_printf(seq, ",session=%u", sbi->session);
        if (sbi->nls_disk)
                seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
        if (sbi->nls_io)
                seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
        if (sbi->s_quiet)
                seq_printf(seq, ",quiet");
        return 0;
}

static struct inode *hfs_alloc_inode(struct super_block *sb)
{
        struct hfs_inode_info *i;

        i = alloc_inode_sb(sb, hfs_inode_cachep, GFP_KERNEL);
        return i ? &i->vfs_inode : NULL;
}

static void hfs_free_inode(struct inode *inode)
{
        kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
}

static const struct super_operations hfs_super_operations = {
        .alloc_inode    = hfs_alloc_inode,
        .free_inode     = hfs_free_inode,
        .write_inode    = hfs_write_inode,
        .evict_inode    = hfs_evict_inode,
        .put_super      = hfs_put_super,
        .sync_fs        = hfs_sync_fs,
        .statfs         = hfs_statfs,
        .show_options   = hfs_show_options,
};

enum {
        opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
        opt_part, opt_session, opt_type, opt_creator, opt_quiet,
        opt_codepage, opt_iocharset,
};

static const struct fs_parameter_spec hfs_param_spec[] = {
        fsparam_u32     ("uid",         opt_uid),
        fsparam_u32     ("gid",         opt_gid),
        fsparam_u32oct  ("umask",       opt_umask),
        fsparam_u32oct  ("file_umask",  opt_file_umask),
        fsparam_u32oct  ("dir_umask",   opt_dir_umask),
        fsparam_u32     ("part",        opt_part),
        fsparam_u32     ("session",     opt_session),
        fsparam_string  ("type",        opt_type),
        fsparam_string  ("creator",     opt_creator),
        fsparam_flag    ("quiet",       opt_quiet),
        fsparam_string  ("codepage",    opt_codepage),
        fsparam_string  ("iocharset",   opt_iocharset),
        {}
};

/*
 * hfs_parse_param()
 *
 * This function is called by the vfs to parse the mount options.
 */
static int hfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
        struct hfs_sb_info *hsb = fc->s_fs_info;
        struct fs_parse_result result;
        int opt;

        /* hfs does not honor any fs-specific options on remount */
        if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
                return 0;

        opt = fs_parse(fc, hfs_param_spec, param, &result);
        if (opt < 0)
                return opt;

        switch (opt) {
        case opt_uid:
                hsb->s_uid = result.uid;
                break;
        case opt_gid:
                hsb->s_gid = result.gid;
                break;
        case opt_umask:
                hsb->s_file_umask = (umode_t)result.uint_32;
                hsb->s_dir_umask = (umode_t)result.uint_32;
                break;
        case opt_file_umask:
                hsb->s_file_umask = (umode_t)result.uint_32;
                break;
        case opt_dir_umask:
                hsb->s_dir_umask = (umode_t)result.uint_32;
                break;
        case opt_part:
                hsb->part = result.uint_32;
                break;
        case opt_session:
                hsb->session = result.uint_32;
                break;
        case opt_type:
                if (strlen(param->string) != 4) {
                        pr_err("type requires a 4 character value\n");
                        return -EINVAL;
                }
                memcpy(&hsb->s_type, param->string, 4);
                break;
        case opt_creator:
                if (strlen(param->string) != 4) {
                        pr_err("creator requires a 4 character value\n");
                        return -EINVAL;
                }
                memcpy(&hsb->s_creator, param->string, 4);
                break;
        case opt_quiet:
                hsb->s_quiet = 1;
                break;
        case opt_codepage:
                if (hsb->nls_disk) {
                        pr_err("unable to change codepage\n");
                        return -EINVAL;
                }
                hsb->nls_disk = load_nls(param->string);
                if (!hsb->nls_disk) {
                        pr_err("unable to load codepage \"%s\"\n",
                                        param->string);
                        return -EINVAL;
                }
                break;
        case opt_iocharset:
                if (hsb->nls_io) {
                        pr_err("unable to change iocharset\n");
                        return -EINVAL;
                }
                hsb->nls_io = load_nls(param->string);
                if (!hsb->nls_io) {
                        pr_err("unable to load iocharset \"%s\"\n",
                                        param->string);
                        return -EINVAL;
                }
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

/*
 * hfs_read_super()
 *
 * This is the function that is responsible for mounting an HFS
 * filesystem.  It performs all the tasks necessary to get enough data
 * from the disk to read the root inode.  This includes parsing the
 * mount options, dealing with Macintosh partitions, reading the
 * superblock and the allocation bitmap blocks, calling
 * hfs_btree_init() to get the necessary data about the extents and
 * catalog B-trees and, finally, reading the root inode into memory.
 */
static int hfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
        struct hfs_sb_info *sbi = HFS_SB(sb);
        struct hfs_find_data fd;
        hfs_cat_rec rec;
        struct inode *root_inode;
        int silent = fc->sb_flags & SB_SILENT;
        int res;

        atomic64_set(&sbi->file_count, 0);
        atomic64_set(&sbi->folder_count, 0);
        atomic64_set(&sbi->next_id, 0);

        /* load_nls_default does not fail */
        if (sbi->nls_disk && !sbi->nls_io)
                sbi->nls_io = load_nls_default();
        sbi->s_dir_umask &= 0777;
        sbi->s_file_umask &= 0577;

        spin_lock_init(&sbi->work_lock);
        INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);

        sbi->sb = sb;
        sb->s_op = &hfs_super_operations;
        sb->s_xattr = hfs_xattr_handlers;
        sb->s_flags |= SB_NODIRATIME;
        mutex_init(&sbi->bitmap_lock);

        res = hfs_mdb_get(sb);
        if (res) {
                if (!silent)
                        pr_warn("can't find a HFS filesystem on dev %s\n",
                                hfs_mdb_name(sb));
                res = -EINVAL;
                goto bail;
        }

        /* try to get the root inode */
        res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
        if (res)
                goto bail_no_root;
        res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
        if (!res) {
                if (fd.entrylength != sizeof(rec.dir)) {
                        res =  -EIO;
                        goto bail_hfs_find;
                }
                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
                if (rec.type != HFS_CDR_DIR)
                        res = -EIO;
        }
        if (res)
                goto bail_hfs_find;
        res = -EINVAL;
        root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
        hfs_find_exit(&fd);
        if (!root_inode)
                goto bail_no_root;

        set_default_d_op(sb, &hfs_dentry_operations);
        res = -ENOMEM;
        sb->s_root = d_make_root(root_inode);
        if (!sb->s_root)
                goto bail_no_root;

        /* everything's okay */
        return 0;

bail_hfs_find:
        hfs_find_exit(&fd);
bail_no_root:
        pr_err("get root inode failed\n");
bail:
        hfs_mdb_put(sb);
        return res;
}

static int hfs_get_tree(struct fs_context *fc)
{
        return get_tree_bdev(fc, hfs_fill_super);
}

static void hfs_free_fc(struct fs_context *fc)
{
        kfree(fc->s_fs_info);
}

static const struct fs_context_operations hfs_context_ops = {
        .parse_param    = hfs_parse_param,
        .get_tree       = hfs_get_tree,
        .reconfigure    = hfs_reconfigure,
        .free           = hfs_free_fc,
};

static int hfs_init_fs_context(struct fs_context *fc)
{
        struct hfs_sb_info *hsb;

        hsb = kzalloc_obj(struct hfs_sb_info);
        if (!hsb)
                return -ENOMEM;

        fc->s_fs_info = hsb;
        fc->ops = &hfs_context_ops;

        if (fc->purpose != FS_CONTEXT_FOR_RECONFIGURE) {
                /* initialize options with defaults */
                hsb->s_uid = current_uid();
                hsb->s_gid = current_gid();
                hsb->s_file_umask = 0133;
                hsb->s_dir_umask = 0022;
                hsb->s_type = cpu_to_be32(0x3f3f3f3f); /* == '????' */
                hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
                hsb->s_quiet = 0;
                hsb->part = -1;
                hsb->session = -1;
        }

        return 0;
}

static void hfs_kill_super(struct super_block *sb)
{
        struct hfs_sb_info *hsb = HFS_SB(sb);

        kill_block_super(sb);
        kfree(hsb);
}

static struct file_system_type hfs_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "hfs",
        .kill_sb        = hfs_kill_super,
        .fs_flags       = FS_REQUIRES_DEV,
        .init_fs_context = hfs_init_fs_context,
};
MODULE_ALIAS_FS("hfs");

static void hfs_init_once(void *p)
{
        struct hfs_inode_info *i = p;

        inode_init_once(&i->vfs_inode);
}

static int __init init_hfs_fs(void)
{
        int err;

        hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
                sizeof(struct hfs_inode_info), 0,
                SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
        if (!hfs_inode_cachep)
                return -ENOMEM;
        err = register_filesystem(&hfs_fs_type);
        if (err)
                kmem_cache_destroy(hfs_inode_cachep);
        return err;
}

static void __exit exit_hfs_fs(void)
{
        unregister_filesystem(&hfs_fs_type);

        /*
         * Make sure all delayed rcu free inodes are flushed before we
         * destroy cache.
         */
        rcu_barrier();
        kmem_cache_destroy(hfs_inode_cachep);
}

module_init(init_hfs_fs)
module_exit(exit_hfs_fs)