/*
 *  linux/fs/hfs/inode.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 inode-related functions which do not depend on
 * which scheme is being used to represent forks.
 *
 * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
 */

#include <linux/pagemap.h>
#include <linux/mpage.h>
#include <linux/sched.h>

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

static const struct file_operations hfs_file_operations;
static const struct inode_operations hfs_file_inode_operations;

/*================ Variable-like macros ================*/

#define HFS_VALID_MODE_BITS  (S_IFREG | S_IFDIR | S_IRWXUGO)

static int hfs_writepage(struct page *page, struct writeback_control *wbc)
{
        return block_write_full_page(page, hfs_get_block, wbc);
}

static int hfs_readpage(struct file *file, struct page *page)
{
        return block_read_full_page(page, hfs_get_block);
}

static int hfs_write_begin(struct file *file, struct address_space *mapping,
                        loff_t pos, unsigned len, unsigned flags,
                        struct page **pagep, void **fsdata)
{
        *pagep = NULL;
        return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
                                hfs_get_block,
                                &HFS_I(mapping->host)->phys_size);
}

static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
{
        return generic_block_bmap(mapping, block, hfs_get_block);
}

static int hfs_releasepage(struct page *page, gfp_t mask)
{
        struct inode *inode = page->mapping->host;
        struct super_block *sb = inode->i_sb;
        struct hfs_btree *tree;
        struct hfs_bnode *node;
        u32 nidx;
        int i, res = 1;

        switch (inode->i_ino) {
        case HFS_EXT_CNID:
                tree = HFS_SB(sb)->ext_tree;
                break;
        case HFS_CAT_CNID:
                tree = HFS_SB(sb)->cat_tree;
                break;
        default:
                BUG();
                return 0;
        }
        if (tree->node_size >= PAGE_CACHE_SIZE) {
                nidx = page->index >> (tree->node_size_shift - PAGE_CACHE_SHIFT);
                spin_lock(&tree->hash_lock);
                node = hfs_bnode_findhash(tree, nidx);
                if (!node)
                        ;
                else if (atomic_read(&node->refcnt))
                        res = 0;
                if (res && node) {
                        hfs_bnode_unhash(node);
                        hfs_bnode_free(node);
                }
                spin_unlock(&tree->hash_lock);
        } else {
                nidx = page->index << (PAGE_CACHE_SHIFT - tree->node_size_shift);
                i = 1 << (PAGE_CACHE_SHIFT - tree->node_size_shift);
                spin_lock(&tree->hash_lock);
                do {
                        node = hfs_bnode_findhash(tree, nidx++);
                        if (!node)
                                continue;
                        if (atomic_read(&node->refcnt)) {
                                res = 0;
                                break;
                        }
                        hfs_bnode_unhash(node);
                        hfs_bnode_free(node);
                } while (--i && nidx < tree->node_count);
                spin_unlock(&tree->hash_lock);
        }
        return res ? try_to_free_buffers(page) : 0;
}

static ssize_t hfs_direct_IO(int rw, struct kiocb *iocb,
                const struct iovec *iov, loff_t offset, unsigned long nr_segs)
{
        struct file *file = iocb->ki_filp;
        struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;

        return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
                                  offset, nr_segs, hfs_get_block, NULL);
}

static int hfs_writepages(struct address_space *mapping,
                          struct writeback_control *wbc)
{
        return mpage_writepages(mapping, wbc, hfs_get_block);
}

const struct address_space_operations hfs_btree_aops = {
        .readpage       = hfs_readpage,
        .writepage      = hfs_writepage,
        .sync_page      = block_sync_page,
        .write_begin    = hfs_write_begin,
        .write_end      = generic_write_end,
        .bmap           = hfs_bmap,
        .releasepage    = hfs_releasepage,
};

const struct address_space_operations hfs_aops = {
        .readpage       = hfs_readpage,
        .writepage      = hfs_writepage,
        .sync_page      = block_sync_page,
        .write_begin    = hfs_write_begin,
        .write_end      = generic_write_end,
        .bmap           = hfs_bmap,
        .direct_IO      = hfs_direct_IO,
        .writepages     = hfs_writepages,
};

/*
 * hfs_new_inode
 */
struct inode *hfs_new_inode(struct inode *dir, struct qstr *name, int mode)
{
        struct super_block *sb = dir->i_sb;
        struct inode *inode = new_inode(sb);
        if (!inode)
                return NULL;

        init_MUTEX(&HFS_I(inode)->extents_lock);
        INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
        hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
        inode->i_ino = HFS_SB(sb)->next_id++;
        inode->i_mode = mode;
        inode->i_uid = current->fsuid;
        inode->i_gid = current->fsgid;
        inode->i_nlink = 1;
        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
        HFS_I(inode)->flags = 0;
        HFS_I(inode)->rsrc_inode = NULL;
        HFS_I(inode)->fs_blocks = 0;
        if (S_ISDIR(mode)) {
                inode->i_size = 2;
                HFS_SB(sb)->folder_count++;
                if (dir->i_ino == HFS_ROOT_CNID)
                        HFS_SB(sb)->root_dirs++;
                inode->i_op = &hfs_dir_inode_operations;
                inode->i_fop = &hfs_dir_operations;
                inode->i_mode |= S_IRWXUGO;
                inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
        } else if (S_ISREG(mode)) {
                HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
                HFS_SB(sb)->file_count++;
                if (dir->i_ino == HFS_ROOT_CNID)
                        HFS_SB(sb)->root_files++;
                inode->i_op = &hfs_file_inode_operations;
                inode->i_fop = &hfs_file_operations;
                inode->i_mapping->a_ops = &hfs_aops;
                inode->i_mode |= S_IRUGO|S_IXUGO;
                if (mode & S_IWUSR)
                        inode->i_mode |= S_IWUGO;
                inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
                HFS_I(inode)->phys_size = 0;
                HFS_I(inode)->alloc_blocks = 0;
                HFS_I(inode)->first_blocks = 0;
                HFS_I(inode)->cached_start = 0;
                HFS_I(inode)->cached_blocks = 0;
                memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
                memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
        }
        insert_inode_hash(inode);
        mark_inode_dirty(inode);
        set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
        sb->s_dirt = 1;

        return inode;
}

void hfs_delete_inode(struct inode *inode)
{
        struct super_block *sb = inode->i_sb;

        dprint(DBG_INODE, "delete_inode: %lu\n", inode->i_ino);
        if (S_ISDIR(inode->i_mode)) {
                HFS_SB(sb)->folder_count--;
                if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
                        HFS_SB(sb)->root_dirs--;
                set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
                sb->s_dirt = 1;
                return;
        }
        HFS_SB(sb)->file_count--;
        if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
                HFS_SB(sb)->root_files--;
        if (S_ISREG(inode->i_mode)) {
                if (!inode->i_nlink) {
                        inode->i_size = 0;
                        hfs_file_truncate(inode);
                }
        }
        set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
        sb->s_dirt = 1;
}

void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
                         __be32 __log_size, __be32 phys_size, u32 clump_size)
{
        struct super_block *sb = inode->i_sb;
        u32 log_size = be32_to_cpu(__log_size);
        u16 count;
        int i;

        memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
        for (count = 0, i = 0; i < 3; i++)
                count += be16_to_cpu(ext[i].count);
        HFS_I(inode)->first_blocks = count;

        inode->i_size = HFS_I(inode)->phys_size = log_size;
        HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
        inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
        HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
                                     HFS_SB(sb)->alloc_blksz;
        HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
        if (!HFS_I(inode)->clump_blocks)
                HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
}

struct hfs_iget_data {
        struct hfs_cat_key *key;
        hfs_cat_rec *rec;
};

static int hfs_test_inode(struct inode *inode, void *data)
{
        struct hfs_iget_data *idata = data;
        hfs_cat_rec *rec;

        rec = idata->rec;
        switch (rec->type) {
        case HFS_CDR_DIR:
                return inode->i_ino == be32_to_cpu(rec->dir.DirID);
        case HFS_CDR_FIL:
                return inode->i_ino == be32_to_cpu(rec->file.FlNum);
        default:
                BUG();
                return 1;
        }
}

/*
 * hfs_read_inode
 */
static int hfs_read_inode(struct inode *inode, void *data)
{
        struct hfs_iget_data *idata = data;
        struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
        hfs_cat_rec *rec;

        HFS_I(inode)->flags = 0;
        HFS_I(inode)->rsrc_inode = NULL;
        init_MUTEX(&HFS_I(inode)->extents_lock);
        INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);

        /* Initialize the inode */
        inode->i_uid = hsb->s_uid;
        inode->i_gid = hsb->s_gid;
        inode->i_nlink = 1;

        if (idata->key)
                HFS_I(inode)->cat_key = *idata->key;
        else
                HFS_I(inode)->flags |= HFS_FLG_RSRC;
        HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;

        rec = idata->rec;
        switch (rec->type) {
        case HFS_CDR_FIL:
                if (!HFS_IS_RSRC(inode)) {
                        hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
                                            rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
                } else {
                        hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
                                            rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
                }

                inode->i_ino = be32_to_cpu(rec->file.FlNum);
                inode->i_mode = S_IRUGO | S_IXUGO;
                if (!(rec->file.Flags & HFS_FIL_LOCK))
                        inode->i_mode |= S_IWUGO;
                inode->i_mode &= ~hsb->s_file_umask;
                inode->i_mode |= S_IFREG;
                inode->i_ctime = inode->i_atime = inode->i_mtime =
                                hfs_m_to_utime(rec->file.MdDat);
                inode->i_op = &hfs_file_inode_operations;
                inode->i_fop = &hfs_file_operations;
                inode->i_mapping->a_ops = &hfs_aops;
                break;
        case HFS_CDR_DIR:
                inode->i_ino = be32_to_cpu(rec->dir.DirID);
                inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
                HFS_I(inode)->fs_blocks = 0;
                inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
                inode->i_ctime = inode->i_atime = inode->i_mtime =
                                hfs_m_to_utime(rec->dir.MdDat);
                inode->i_op = &hfs_dir_inode_operations;
                inode->i_fop = &hfs_dir_operations;
                break;
        default:
                make_bad_inode(inode);
        }
        return 0;
}

/*
 * __hfs_iget()
 *
 * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
 * the catalog B-tree and the 'type' of the desired file return the
 * inode for that file/directory or NULL.  Note that 'type' indicates
 * whether we want the actual file or directory, or the corresponding
 * metadata (AppleDouble header file or CAP metadata file).
 */
struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
{
        struct hfs_iget_data data = { key, rec };
        struct inode *inode;
        u32 cnid;

        switch (rec->type) {
        case HFS_CDR_DIR:
                cnid = be32_to_cpu(rec->dir.DirID);
                break;
        case HFS_CDR_FIL:
                cnid = be32_to_cpu(rec->file.FlNum);
                break;
        default:
                return NULL;
        }
        inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
        if (inode && (inode->i_state & I_NEW))
                unlock_new_inode(inode);
        return inode;
}

void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
                          __be32 *log_size, __be32 *phys_size)
{
        memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));

        if (log_size)
                *log_size = cpu_to_be32(inode->i_size);
        if (phys_size)
                *phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
                                         HFS_SB(inode->i_sb)->alloc_blksz);
}

int hfs_write_inode(struct inode *inode, int unused)
{
        struct inode *main_inode = inode;
        struct hfs_find_data fd;
        hfs_cat_rec rec;

        dprint(DBG_INODE, "hfs_write_inode: %lu\n", inode->i_ino);
        hfs_ext_write_extent(inode);

        if (inode->i_ino < HFS_FIRSTUSER_CNID) {
                switch (inode->i_ino) {
                case HFS_ROOT_CNID:
                        break;
                case HFS_EXT_CNID:
                        hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
                        return 0;
                case HFS_CAT_CNID:
                        hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
                        return 0;
                default:
                        BUG();
                        return -EIO;
                }
        }

        if (HFS_IS_RSRC(inode))
                main_inode = HFS_I(inode)->rsrc_inode;

        if (!main_inode->i_nlink)
                return 0;

        if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
                /* panic? */
                return -EIO;

        fd.search_key->cat = HFS_I(main_inode)->cat_key;
        if (hfs_brec_find(&fd))
                /* panic? */
                goto out;

        if (S_ISDIR(main_inode->i_mode)) {
                if (fd.entrylength < sizeof(struct hfs_cat_dir))
                        /* panic? */;
                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
                           sizeof(struct hfs_cat_dir));
                if (rec.type != HFS_CDR_DIR ||
                    be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
                }

                rec.dir.MdDat = hfs_u_to_mtime(inode->i_mtime);
                rec.dir.Val = cpu_to_be16(inode->i_size - 2);

                hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
                            sizeof(struct hfs_cat_dir));
        } else if (HFS_IS_RSRC(inode)) {
                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
                               sizeof(struct hfs_cat_file));
                hfs_inode_write_fork(inode, rec.file.RExtRec,
                                     &rec.file.RLgLen, &rec.file.RPyLen);
                hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
                                sizeof(struct hfs_cat_file));
        } else {
                if (fd.entrylength < sizeof(struct hfs_cat_file))
                        /* panic? */;
                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
                           sizeof(struct hfs_cat_file));
                if (rec.type != HFS_CDR_FIL ||
                    be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
                }

                if (inode->i_mode & S_IWUSR)
                        rec.file.Flags &= ~HFS_FIL_LOCK;
                else
                        rec.file.Flags |= HFS_FIL_LOCK;
                hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
                rec.file.MdDat = hfs_u_to_mtime(inode->i_mtime);

                hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
                            sizeof(struct hfs_cat_file));
        }
out:
        hfs_find_exit(&fd);
        return 0;
}

static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
                                      struct nameidata *nd)
{
        struct inode *inode = NULL;
        hfs_cat_rec rec;
        struct hfs_find_data fd;
        int res;

        if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
                goto out;

        inode = HFS_I(dir)->rsrc_inode;
        if (inode)
                goto out;

        inode = new_inode(dir->i_sb);
        if (!inode)
                return ERR_PTR(-ENOMEM);

        hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
        fd.search_key->cat = HFS_I(dir)->cat_key;
        res = hfs_brec_read(&fd, &rec, sizeof(rec));
        if (!res) {
                struct hfs_iget_data idata = { NULL, &rec };
                hfs_read_inode(inode, &idata);
        }
        hfs_find_exit(&fd);
        if (res) {
                iput(inode);
                return ERR_PTR(res);
        }
        HFS_I(inode)->rsrc_inode = dir;
        HFS_I(dir)->rsrc_inode = inode;
        igrab(dir);
        hlist_add_head(&inode->i_hash, &HFS_SB(dir->i_sb)->rsrc_inodes);
        mark_inode_dirty(inode);
out:
        d_add(dentry, inode);
        return NULL;
}

void hfs_clear_inode(struct inode *inode)
{
        if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
                HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
                iput(HFS_I(inode)->rsrc_inode);
        }
}

static int hfs_permission(struct inode *inode, int mask,
                          struct nameidata *nd)
{
        if (S_ISREG(inode->i_mode) && mask & MAY_EXEC)
                return 0;
        return generic_permission(inode, mask, NULL);
}

static int hfs_file_open(struct inode *inode, struct file *file)
{
        if (HFS_IS_RSRC(inode))
                inode = HFS_I(inode)->rsrc_inode;
        if (atomic_read(&file->f_count) != 1)
                return 0;
        atomic_inc(&HFS_I(inode)->opencnt);
        return 0;
}

static int hfs_file_release(struct inode *inode, struct file *file)
{
        //struct super_block *sb = inode->i_sb;

        if (HFS_IS_RSRC(inode))
                inode = HFS_I(inode)->rsrc_inode;
        if (atomic_read(&file->f_count) != 0)
                return 0;
        if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
                mutex_lock(&inode->i_mutex);
                hfs_file_truncate(inode);
                //if (inode->i_flags & S_DEAD) {
                //      hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
                //      hfs_delete_inode(inode);
                //}
                mutex_unlock(&inode->i_mutex);
        }
        return 0;
}

/*
 * hfs_notify_change()
 *
 * Based very closely on fs/msdos/inode.c by Werner Almesberger
 *
 * This is the notify_change() field in the super_operations structure
 * for HFS file systems.  The purpose is to take that changes made to
 * an inode and apply then in a filesystem-dependent manner.  In this
 * case the process has a few of tasks to do:
 *  1) prevent changes to the i_uid and i_gid fields.
 *  2) map file permissions to the closest allowable permissions
 *  3) Since multiple Linux files can share the same on-disk inode under
 *     HFS (for instance the data and resource forks of a file) a change
 *     to permissions must be applied to all other in-core inodes which
 *     correspond to the same HFS file.
 */

int hfs_inode_setattr(struct dentry *dentry, struct iattr * attr)
{
        struct inode *inode = dentry->d_inode;
        struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
        int error;

        error = inode_change_ok(inode, attr); /* basic permission checks */
        if (error)
                return error;

        /* no uig/gid changes and limit which mode bits can be set */
        if (((attr->ia_valid & ATTR_UID) &&
             (attr->ia_uid != hsb->s_uid)) ||
            ((attr->ia_valid & ATTR_GID) &&
             (attr->ia_gid != hsb->s_gid)) ||
            ((attr->ia_valid & ATTR_MODE) &&
             ((S_ISDIR(inode->i_mode) &&
               (attr->ia_mode != inode->i_mode)) ||
              (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
                return hsb->s_quiet ? 0 : error;
        }

        if (attr->ia_valid & ATTR_MODE) {
                /* Only the 'w' bits can ever change and only all together. */
                if (attr->ia_mode & S_IWUSR)
                        attr->ia_mode = inode->i_mode | S_IWUGO;
                else
                        attr->ia_mode = inode->i_mode & ~S_IWUGO;
                attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
        }
        error = inode_setattr(inode, attr);
        if (error)
                return error;

        return 0;
}


static const struct file_operations hfs_file_operations = {
        .llseek         = generic_file_llseek,
        .read           = do_sync_read,
        .aio_read       = generic_file_aio_read,
        .write          = do_sync_write,
        .aio_write      = generic_file_aio_write,
        .mmap           = generic_file_mmap,
        .splice_read    = generic_file_splice_read,
        .fsync          = file_fsync,
        .open           = hfs_file_open,
        .release        = hfs_file_release,
};

static const struct inode_operations hfs_file_inode_operations = {
        .lookup         = hfs_file_lookup,
        .truncate       = hfs_file_truncate,
        .setattr        = hfs_inode_setattr,
        .permission     = hfs_permission,
        .setxattr       = hfs_setxattr,
        .getxattr       = hfs_getxattr,
        .listxattr      = hfs_listxattr,
};