/*
 * This file is part of UBIFS.
 *
 * Copyright (C) 2006-2008 Nokia Corporation.
 *
 * (C) Copyright 2008-2010
 * Stefan Roese, DENX Software Engineering, sr@denx.de.
 *
 * Authors: Artem Bityutskiy (Битюцкий Артём)
 *          Adrian Hunter
 *
 * SPDX-License-Identifier:     GPL-2.0
 */

#include <common.h>
#include <memalign.h>
#include "ubifs.h"
#include <u-boot/zlib.h>

#include <linux/err.h>
#include <linux/lzo.h>

DECLARE_GLOBAL_DATA_PTR;

/* compress.c */

/*
 * We need a wrapper for zunzip() because the parameters are
 * incompatible with the lzo decompressor.
 */
static int gzip_decompress(const unsigned char *in, size_t in_len,
                           unsigned char *out, size_t *out_len)
{
        return zunzip(out, *out_len, (unsigned char *)in,
                      (unsigned long *)out_len, 0, 0);
}

/* Fake description object for the "none" compressor */
static struct ubifs_compressor none_compr = {
        .compr_type = UBIFS_COMPR_NONE,
        .name = "none",
        .capi_name = "",
        .decompress = NULL,
};

static struct ubifs_compressor lzo_compr = {
        .compr_type = UBIFS_COMPR_LZO,
#ifndef __UBOOT__
        .comp_mutex = &lzo_mutex,
#endif
        .name = "lzo",
        .capi_name = "lzo",
        .decompress = lzo1x_decompress_safe,
};

static struct ubifs_compressor zlib_compr = {
        .compr_type = UBIFS_COMPR_ZLIB,
#ifndef __UBOOT__
        .comp_mutex = &deflate_mutex,
        .decomp_mutex = &inflate_mutex,
#endif
        .name = "zlib",
        .capi_name = "deflate",
        .decompress = gzip_decompress,
};

/* All UBIFS compressors */
struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];


#ifdef __UBOOT__
/* from mm/util.c */

/**
 * kmemdup - duplicate region of memory
 *
 * @src: memory region to duplicate
 * @len: memory region length
 * @gfp: GFP mask to use
 */
void *kmemdup(const void *src, size_t len, gfp_t gfp)
{
        void *p;

        p = kmalloc(len, gfp);
        if (p)
                memcpy(p, src, len);
        return p;
}

struct crypto_comp {
        int compressor;
};

static inline struct crypto_comp
*crypto_alloc_comp(const char *alg_name, u32 type, u32 mask)
{
        struct ubifs_compressor *comp;
        struct crypto_comp *ptr;
        int i = 0;

        ptr = malloc_cache_aligned(sizeof(struct crypto_comp));
        while (i < UBIFS_COMPR_TYPES_CNT) {
                comp = ubifs_compressors[i];
                if (!comp) {
                        i++;
                        continue;
                }
                if (strncmp(alg_name, comp->capi_name, strlen(alg_name)) == 0) {
                        ptr->compressor = i;
                        return ptr;
                }
                i++;
        }
        if (i >= UBIFS_COMPR_TYPES_CNT) {
                dbg_gen("invalid compression type %s", alg_name);
                free (ptr);
                return NULL;
        }
        return ptr;
}
static inline int
crypto_comp_decompress(const struct ubifs_info *c, struct crypto_comp *tfm,
                       const u8 *src, unsigned int slen, u8 *dst,
                       unsigned int *dlen)
{
        struct ubifs_compressor *compr = ubifs_compressors[tfm->compressor];
        int err;

        if (compr->compr_type == UBIFS_COMPR_NONE) {
                memcpy(dst, src, slen);
                *dlen = slen;
                return 0;
        }

        err = compr->decompress(src, slen, dst, (size_t *)dlen);
        if (err)
                ubifs_err(c, "cannot decompress %d bytes, compressor %s, "
                          "error %d", slen, compr->name, err);

        return err;

        return 0;
}

/* from shrinker.c */

/* Global clean znode counter (for all mounted UBIFS instances) */
atomic_long_t ubifs_clean_zn_cnt;

#endif

/**
 * ubifs_decompress - decompress data.
 * @in_buf: data to decompress
 * @in_len: length of the data to decompress
 * @out_buf: output buffer where decompressed data should
 * @out_len: output length is returned here
 * @compr_type: type of compression
 *
 * This function decompresses data from buffer @in_buf into buffer @out_buf.
 * The length of the uncompressed data is returned in @out_len. This functions
 * returns %0 on success or a negative error code on failure.
 */
int ubifs_decompress(const struct ubifs_info *c, const void *in_buf,
                     int in_len, void *out_buf, int *out_len, int compr_type)
{
        int err;
        struct ubifs_compressor *compr;

        if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {
                ubifs_err(c, "invalid compression type %d", compr_type);
                return -EINVAL;
        }

        compr = ubifs_compressors[compr_type];

        if (unlikely(!compr->capi_name)) {
                ubifs_err(c, "%s compression is not compiled in", compr->name);
                return -EINVAL;
        }

        if (compr_type == UBIFS_COMPR_NONE) {
                memcpy(out_buf, in_buf, in_len);
                *out_len = in_len;
                return 0;
        }

        if (compr->decomp_mutex)
                mutex_lock(compr->decomp_mutex);
        err = crypto_comp_decompress(c, compr->cc, in_buf, in_len, out_buf,
                                     (unsigned int *)out_len);
        if (compr->decomp_mutex)
                mutex_unlock(compr->decomp_mutex);
        if (err)
                ubifs_err(c, "cannot decompress %d bytes, compressor %s,"
                          " error %d", in_len, compr->name, err);

        return err;
}

/**
 * compr_init - initialize a compressor.
 * @compr: compressor description object
 *
 * This function initializes the requested compressor and returns zero in case
 * of success or a negative error code in case of failure.
 */
static int __init compr_init(struct ubifs_compressor *compr)
{
        ubifs_compressors[compr->compr_type] = compr;

#ifdef CONFIG_NEEDS_MANUAL_RELOC
        ubifs_compressors[compr->compr_type]->name += gd->reloc_off;
        ubifs_compressors[compr->compr_type]->capi_name += gd->reloc_off;
        ubifs_compressors[compr->compr_type]->decompress += gd->reloc_off;
#endif

        if (compr->capi_name) {
                compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0);
                if (IS_ERR(compr->cc)) {
                        dbg_gen("cannot initialize compressor %s,"
                                  " error %ld", compr->name,
                                  PTR_ERR(compr->cc));
                        return PTR_ERR(compr->cc);
                }
        }

        return 0;
}

/**
 * ubifs_compressors_init - initialize UBIFS compressors.
 *
 * This function initializes the compressor which were compiled in. Returns
 * zero in case of success and a negative error code in case of failure.
 */
int __init ubifs_compressors_init(void)
{
        int err;

        err = compr_init(&lzo_compr);
        if (err)
                return err;

        err = compr_init(&zlib_compr);
        if (err)
                return err;

        err = compr_init(&none_compr);
        if (err)
                return err;

        return 0;
}

/*
 * ubifsls...
 */

static int filldir(struct ubifs_info *c, const char *name, int namlen,
                   u64 ino, unsigned int d_type)
{
        struct inode *inode;
        char filetime[32];

        switch (d_type) {
        case UBIFS_ITYPE_REG:
                printf("\t");
                break;
        case UBIFS_ITYPE_DIR:
                printf("<DIR>\t");
                break;
        case UBIFS_ITYPE_LNK:
                printf("<LNK>\t");
                break;
        default:
                printf("other\t");
                break;
        }

        inode = ubifs_iget(c->vfs_sb, ino);
        if (IS_ERR(inode)) {
                printf("%s: Error in ubifs_iget(), ino=%lld ret=%p!\n",
                       __func__, ino, inode);
                return -1;
        }
        ctime_r((time_t *)&inode->i_mtime, filetime);
        printf("%9lld  %24.24s  ", inode->i_size, filetime);
#ifndef __UBOOT__
        ubifs_iput(inode);
#endif

        printf("%s\n", name);

        return 0;
}

static int ubifs_printdir(struct file *file, void *dirent)
{
        int err, over = 0;
        struct qstr nm;
        union ubifs_key key;
        struct ubifs_dent_node *dent;
        struct inode *dir = file->f_path.dentry->d_inode;
        struct ubifs_info *c = dir->i_sb->s_fs_info;

        dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);

        if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2)
                /*
                 * The directory was seek'ed to a senseless position or there
                 * are no more entries.
                 */
                return 0;

        if (file->f_pos == 1) {
                /* Find the first entry in TNC and save it */
                lowest_dent_key(c, &key, dir->i_ino);
                nm.name = NULL;
                dent = ubifs_tnc_next_ent(c, &key, &nm);
                if (IS_ERR(dent)) {
                        err = PTR_ERR(dent);
                        goto out;
                }

                file->f_pos = key_hash_flash(c, &dent->key);
                file->private_data = dent;
        }

        dent = file->private_data;
        if (!dent) {
                /*
                 * The directory was seek'ed to and is now readdir'ed.
                 * Find the entry corresponding to @file->f_pos or the
                 * closest one.
                 */
                dent_key_init_hash(c, &key, dir->i_ino, file->f_pos);
                nm.name = NULL;
                dent = ubifs_tnc_next_ent(c, &key, &nm);
                if (IS_ERR(dent)) {
                        err = PTR_ERR(dent);
                        goto out;
                }
                file->f_pos = key_hash_flash(c, &dent->key);
                file->private_data = dent;
        }

        while (1) {
                dbg_gen("feed '%s', ino %llu, new f_pos %#x",
                        dent->name, (unsigned long long)le64_to_cpu(dent->inum),
                        key_hash_flash(c, &dent->key));
                ubifs_assert(le64_to_cpu(dent->ch.sqnum) > ubifs_inode(dir)->creat_sqnum);

                nm.len = le16_to_cpu(dent->nlen);
                over = filldir(c, (char *)dent->name, nm.len,
                               le64_to_cpu(dent->inum), dent->type);
                if (over)
                        return 0;

                /* Switch to the next entry */
                key_read(c, &dent->key, &key);
                nm.name = (char *)dent->name;
                dent = ubifs_tnc_next_ent(c, &key, &nm);
                if (IS_ERR(dent)) {
                        err = PTR_ERR(dent);
                        goto out;
                }

                kfree(file->private_data);
                file->f_pos = key_hash_flash(c, &dent->key);
                file->private_data = dent;
                cond_resched();
        }

out:
        if (err != -ENOENT) {
                ubifs_err(c, "cannot find next direntry, error %d", err);
                return err;
        }

        kfree(file->private_data);
        file->private_data = NULL;
        file->f_pos = 2;
        return 0;
}

static int ubifs_finddir(struct super_block *sb, char *dirname,
                         unsigned long root_inum, unsigned long *inum)
{
        int err;
        struct qstr nm;
        union ubifs_key key;
        struct ubifs_dent_node *dent;
        struct ubifs_info *c;
        struct file *file;
        struct dentry *dentry;
        struct inode *dir;
        int ret = 0;

        file = kzalloc(sizeof(struct file), 0);
        dentry = kzalloc(sizeof(struct dentry), 0);
        dir = kzalloc(sizeof(struct inode), 0);
        if (!file || !dentry || !dir) {
                printf("%s: Error, no memory for malloc!\n", __func__);
                err = -ENOMEM;
                goto out;
        }

        dir->i_sb = sb;
        file->f_path.dentry = dentry;
        file->f_path.dentry->d_parent = dentry;
        file->f_path.dentry->d_inode = dir;
        file->f_path.dentry->d_inode->i_ino = root_inum;
        c = sb->s_fs_info;

        dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);

        /* Find the first entry in TNC and save it */
        lowest_dent_key(c, &key, dir->i_ino);
        nm.name = NULL;
        dent = ubifs_tnc_next_ent(c, &key, &nm);
        if (IS_ERR(dent)) {
                err = PTR_ERR(dent);
                goto out;
        }

        file->f_pos = key_hash_flash(c, &dent->key);
        file->private_data = dent;

        while (1) {
                dbg_gen("feed '%s', ino %llu, new f_pos %#x",
                        dent->name, (unsigned long long)le64_to_cpu(dent->inum),
                        key_hash_flash(c, &dent->key));
                ubifs_assert(le64_to_cpu(dent->ch.sqnum) > ubifs_inode(dir)->creat_sqnum);

                nm.len = le16_to_cpu(dent->nlen);
                if ((strncmp(dirname, (char *)dent->name, nm.len) == 0) &&
                    (strlen(dirname) == nm.len)) {
                        *inum = le64_to_cpu(dent->inum);
                        ret = 1;
                        goto out_free;
                }

                /* Switch to the next entry */
                key_read(c, &dent->key, &key);
                nm.name = (char *)dent->name;
                dent = ubifs_tnc_next_ent(c, &key, &nm);
                if (IS_ERR(dent)) {
                        err = PTR_ERR(dent);
                        goto out;
                }

                kfree(file->private_data);
                file->f_pos = key_hash_flash(c, &dent->key);
                file->private_data = dent;
                cond_resched();
        }

out:
        if (err != -ENOENT)
                dbg_gen("cannot find next direntry, error %d", err);

out_free:
        if (file->private_data)
                kfree(file->private_data);
        if (file)
                free(file);
        if (dentry)
                free(dentry);
        if (dir)
                free(dir);

        return ret;
}

static unsigned long ubifs_findfile(struct super_block *sb, char *filename)
{
        int ret;
        char *next;
        char fpath[128];
        char symlinkpath[128];
        char *name = fpath;
        unsigned long root_inum = 1;
        unsigned long inum;
        int symlink_count = 0; /* Don't allow symlink recursion */
        char link_name[64];

        strcpy(fpath, filename);

        /* Remove all leading slashes */
        while (*name == '/')
                name++;

        /*
         * Handle root-direcoty ('/')
         */
        inum = root_inum;
        if (!name || *name == '\0')
                return inum;

        for (;;) {
                struct inode *inode;
                struct ubifs_inode *ui;

                /* Extract the actual part from the pathname.  */
                next = strchr(name, '/');
                if (next) {
                        /* Remove all leading slashes.  */
                        while (*next == '/')
                                *(next++) = '\0';
                }

                ret = ubifs_finddir(sb, name, root_inum, &inum);
                if (!ret)
                        return 0;
                inode = ubifs_iget(sb, inum);

                if (!inode)
                        return 0;
                ui = ubifs_inode(inode);

                if ((inode->i_mode & S_IFMT) == S_IFLNK) {
                        char buf[128];

                        /* We have some sort of symlink recursion, bail out */
                        if (symlink_count++ > 8) {
                                printf("Symlink recursion, aborting\n");
                                return 0;
                        }
                        memcpy(link_name, ui->data, ui->data_len);
                        link_name[ui->data_len] = '\0';

                        if (link_name[0] == '/') {
                                /* Absolute path, redo everything without
                                 * the leading slash */
                                next = name = link_name + 1;
                                root_inum = 1;
                                continue;
                        }
                        /* Relative to cur dir */
                        sprintf(buf, "%s/%s",
                                        link_name, next == NULL ? "" : next);
                        memcpy(symlinkpath, buf, sizeof(buf));
                        next = name = symlinkpath;
                        continue;
                }

                /*
                 * Check if directory with this name exists
                 */

                /* Found the node!  */
                if (!next || *next == '\0')
                        return inum;

                root_inum = inum;
                name = next;
        }

        return 0;
}

int ubifs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info)
{
        if (rbdd) {
                debug("UBIFS cannot be used with normal block devices\n");
                return -1;
        }

        /*
         * Should never happen since get_device_and_partition() already checks
         * this, but better safe then sorry.
         */
        if (!ubifs_is_mounted()) {
                debug("UBIFS not mounted, use ubifsmount to mount volume first!\n");
                return -1;
        }

        return 0;
}

int ubifs_ls(const char *filename)
{
        struct ubifs_info *c = ubifs_sb->s_fs_info;
        struct file *file;
        struct dentry *dentry;
        struct inode *dir;
        void *dirent = NULL;
        unsigned long inum;
        int ret = 0;

        c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
        inum = ubifs_findfile(ubifs_sb, (char *)filename);
        if (!inum) {
                ret = -1;
                goto out;
        }

        file = kzalloc(sizeof(struct file), 0);
        dentry = kzalloc(sizeof(struct dentry), 0);
        dir = kzalloc(sizeof(struct inode), 0);
        if (!file || !dentry || !dir) {
                printf("%s: Error, no memory for malloc!\n", __func__);
                ret = -ENOMEM;
                goto out_mem;
        }

        dir->i_sb = ubifs_sb;
        file->f_path.dentry = dentry;
        file->f_path.dentry->d_parent = dentry;
        file->f_path.dentry->d_inode = dir;
        file->f_path.dentry->d_inode->i_ino = inum;
        file->f_pos = 1;
        file->private_data = NULL;
        ubifs_printdir(file, dirent);

out_mem:
        if (file)
                free(file);
        if (dentry)
                free(dentry);
        if (dir)
                free(dir);

out:
        ubi_close_volume(c->ubi);
        return ret;
}

int ubifs_exists(const char *filename)
{
        struct ubifs_info *c = ubifs_sb->s_fs_info;
        unsigned long inum;

        c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
        inum = ubifs_findfile(ubifs_sb, (char *)filename);
        ubi_close_volume(c->ubi);

        return inum != 0;
}

int ubifs_size(const char *filename, loff_t *size)
{
        struct ubifs_info *c = ubifs_sb->s_fs_info;
        unsigned long inum;
        struct inode *inode;
        int err = 0;

        c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);

        inum = ubifs_findfile(ubifs_sb, (char *)filename);
        if (!inum) {
                err = -1;
                goto out;
        }

        inode = ubifs_iget(ubifs_sb, inum);
        if (IS_ERR(inode)) {
                printf("%s: Error reading inode %ld!\n", __func__, inum);
                err = PTR_ERR(inode);
                goto out;
        }

        *size = inode->i_size;

        ubifs_iput(inode);
out:
        ubi_close_volume(c->ubi);
        return err;
}

/*
 * ubifsload...
 */

/* file.c */

static inline void *kmap(struct page *page)
{
        return page->addr;
}

static int read_block(struct inode *inode, void *addr, unsigned int block,
                      struct ubifs_data_node *dn)
{
        struct ubifs_info *c = inode->i_sb->s_fs_info;
        int err, len, out_len;
        union ubifs_key key;
        unsigned int dlen;

        data_key_init(c, &key, inode->i_ino, block);
        err = ubifs_tnc_lookup(c, &key, dn);
        if (err) {
                if (err == -ENOENT)
                        /* Not found, so it must be a hole */
                        memset(addr, 0, UBIFS_BLOCK_SIZE);
                return err;
        }

        ubifs_assert(le64_to_cpu(dn->ch.sqnum) > ubifs_inode(inode)->creat_sqnum);

        len = le32_to_cpu(dn->size);
        if (len <= 0 || len > UBIFS_BLOCK_SIZE)
                goto dump;

        dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
        out_len = UBIFS_BLOCK_SIZE;
        err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
                               le16_to_cpu(dn->compr_type));
        if (err || len != out_len)
                goto dump;

        /*
         * Data length can be less than a full block, even for blocks that are
         * not the last in the file (e.g., as a result of making a hole and
         * appending data). Ensure that the remainder is zeroed out.
         */
        if (len < UBIFS_BLOCK_SIZE)
                memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);

        return 0;

dump:
        ubifs_err(c, "bad data node (block %u, inode %lu)",
                  block, inode->i_ino);
        ubifs_dump_node(c, dn);
        return -EINVAL;
}

static int do_readpage(struct ubifs_info *c, struct inode *inode,
                       struct page *page, int last_block_size)
{
        void *addr;
        int err = 0, i;
        unsigned int block, beyond;
        struct ubifs_data_node *dn;
        loff_t i_size = inode->i_size;

        dbg_gen("ino %lu, pg %lu, i_size %lld",
                inode->i_ino, page->index, i_size);

        addr = kmap(page);

        block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
        beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
        if (block >= beyond) {
                /* Reading beyond inode */
                memset(addr, 0, PAGE_CACHE_SIZE);
                goto out;
        }

        dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
        if (!dn)
                return -ENOMEM;

        i = 0;
        while (1) {
                int ret;

                if (block >= beyond) {
                        /* Reading beyond inode */
                        err = -ENOENT;
                        memset(addr, 0, UBIFS_BLOCK_SIZE);
                } else {
                        /*
                         * Reading last block? Make sure to not write beyond
                         * the requested size in the destination buffer.
                         */
                        if (((block + 1) == beyond) || last_block_size) {
                                void *buff;
                                int dlen;

                                /*
                                 * We need to buffer the data locally for the
                                 * last block. This is to not pad the
                                 * destination area to a multiple of
                                 * UBIFS_BLOCK_SIZE.
                                 */
                                buff = malloc_cache_aligned(UBIFS_BLOCK_SIZE);
                                if (!buff) {
                                        printf("%s: Error, malloc fails!\n",
                                               __func__);
                                        err = -ENOMEM;
                                        break;
                                }

                                /* Read block-size into temp buffer */
                                ret = read_block(inode, buff, block, dn);
                                if (ret) {
                                        err = ret;
                                        if (err != -ENOENT) {
                                                free(buff);
                                                break;
                                        }
                                }

                                if (last_block_size)
                                        dlen = last_block_size;
                                else
                                        dlen = le32_to_cpu(dn->size);

                                /* Now copy required size back to dest */
                                memcpy(addr, buff, dlen);

                                free(buff);
                        } else {
                                ret = read_block(inode, addr, block, dn);
                                if (ret) {
                                        err = ret;
                                        if (err != -ENOENT)
                                                break;
                                }
                        }
                }
                if (++i >= UBIFS_BLOCKS_PER_PAGE)
                        break;
                block += 1;
                addr += UBIFS_BLOCK_SIZE;
        }
        if (err) {
                if (err == -ENOENT) {
                        /* Not found, so it must be a hole */
                        dbg_gen("hole");
                        goto out_free;
                }
                ubifs_err(c, "cannot read page %lu of inode %lu, error %d",
                          page->index, inode->i_ino, err);
                goto error;
        }

out_free:
        kfree(dn);
out:
        return 0;

error:
        kfree(dn);
        return err;
}

int ubifs_read(const char *filename, void *buf, loff_t offset,
               loff_t size, loff_t *actread)
{
        struct ubifs_info *c = ubifs_sb->s_fs_info;
        unsigned long inum;
        struct inode *inode;
        struct page page;
        int err = 0;
        int i;
        int count;
        int last_block_size = 0;

        *actread = 0;

        if (offset & (PAGE_SIZE - 1)) {
                printf("ubifs: Error offset must be a multple of %d\n",
                       PAGE_SIZE);
                return -1;
        }

        c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
        /* ubifs_findfile will resolve symlinks, so we know that we get
         * the real file here */
        inum = ubifs_findfile(ubifs_sb, (char *)filename);
        if (!inum) {
                err = -1;
                goto out;
        }

        /*
         * Read file inode
         */
        inode = ubifs_iget(ubifs_sb, inum);
        if (IS_ERR(inode)) {
                printf("%s: Error reading inode %ld!\n", __func__, inum);
                err = PTR_ERR(inode);
                goto out;
        }

        if (offset > inode->i_size) {
                printf("ubifs: Error offset (%lld) > file-size (%lld)\n",
                       offset, size);
                err = -1;
                goto put_inode;
        }

        /*
         * If no size was specified or if size bigger than filesize
         * set size to filesize
         */
        if ((size == 0) || (size > (inode->i_size - offset)))
                size = inode->i_size - offset;

        count = (size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;

        page.addr = buf;
        page.index = offset / PAGE_SIZE;
        page.inode = inode;
        for (i = 0; i < count; i++) {
                /*
                 * Make sure to not read beyond the requested size
                 */
                if (((i + 1) == count) && (size < inode->i_size))
                        last_block_size = size - (i * PAGE_SIZE);

                err = do_readpage(c, inode, &page, last_block_size);
                if (err)
                        break;

                page.addr += PAGE_SIZE;
                page.index++;
        }

        if (err) {
                printf("Error reading file '%s'\n", filename);
                *actread = i * PAGE_SIZE;
        } else {
                *actread = size;
        }

put_inode:
        ubifs_iput(inode);

out:
        ubi_close_volume(c->ubi);
        return err;
}

void ubifs_close(void)
{
}

/* Compat wrappers for common/cmd_ubifs.c */
int ubifs_load(char *filename, u32 addr, u32 size)
{
        loff_t actread;
        int err;

        printf("Loading file '%s' to addr 0x%08x...\n", filename, addr);

        err = ubifs_read(filename, (void *)addr, 0, size, &actread);
        if (err == 0) {
                setenv_hex("filesize", actread);
                printf("Done\n");
        }

        return err;
}

void uboot_ubifs_umount(void)
{
        if (ubifs_sb) {
                printf("Unmounting UBIFS volume %s!\n",
                       ((struct ubifs_info *)(ubifs_sb->s_fs_info))->vi.name);
                ubifs_umount(ubifs_sb->s_fs_info);
                ubifs_sb = NULL;
        }
}