source: mainline/uspace/srv/fs/tmpfs/tmpfs_dump.c@ 9f429c0

/*
 * Copyright (c) 2008 Jakub Jermar 
 * Copyright (c) 2008 Martin Decky 
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup fs
 * @{
 */ 

/**
 * @file        tmpfs_dump.c
 * @brief       Support for loading TMPFS file system dump.
 */

#include "tmpfs.h"
#include "../../vfs/vfs.h"
#include <ipc/ipc.h>
#include <async.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <as.h>
#include <libfs.h>
#include <ipc/services.h>
#include <ipc/devmap.h>
#include <sys/mman.h>
#include <byteorder.h>

#define BLOCK_SIZE                      1024    // FIXME
#define RD_BASE                         1024    // FIXME
#define RD_READ_BLOCK   (RD_BASE + 1)

struct rdentry {
        uint8_t type;
        uint32_t len;
} __attribute__((packed));

static bool 
tmpfs_blockread(int phone, void *buffer, size_t *bufpos, size_t *buflen,
    size_t *pos, void *dst, size_t size)
{
        size_t offset = 0;
        size_t left = size;
        
        while (left > 0) {
                size_t rd;
                
                if (*bufpos + left < *buflen)
                        rd = left;
                else
                        rd = *buflen - *bufpos;
                
                if (rd > 0) {
                        memcpy(dst + offset, buffer + *bufpos, rd);
                        offset += rd;
                        *bufpos += rd;
                        *pos += rd;
                        left -= rd;
                }
                
                if (*bufpos == *buflen) {
                        ipcarg_t retval;
                        int rc = async_req_2_1(phone, RD_READ_BLOCK,
                            *pos / BLOCK_SIZE, BLOCK_SIZE, &retval);
                        if ((rc != EOK) || (retval != EOK))
                                return false;
                        
                        *bufpos = 0;
                        *buflen = BLOCK_SIZE;
                }
        }
        
        return true;
}

static bool
tmpfs_restore_recursion(int phone, void *block, size_t *bufpos, size_t *buflen,
    size_t *pos, tmpfs_dentry_t *parent)
{
        struct rdentry entry;
        libfs_ops_t *ops = &tmpfs_libfs_ops;
        
        do {
                char *fname;
                tmpfs_dentry_t *node;
                uint32_t size;
                
                if (!tmpfs_blockread(phone, block, bufpos, buflen, pos, &entry,
                    sizeof(entry)))
                        return false;
                
                entry.len = uint32_t_le2host(entry.len);
                
                switch (entry.type) {
                case TMPFS_NONE:
                        break;
                case TMPFS_FILE:
                        fname = malloc(entry.len + 1);
                        if (fname == NULL)
                                return false;
                        
                        node = (tmpfs_dentry_t *) ops->create(L_FILE);
                        if (node == NULL) {
                                free(fname);
                                return false;
                        }
                        
                        if (!tmpfs_blockread(phone, block, bufpos, buflen, pos,
                            fname, entry.len)) {
                                ops->destroy((void *) node);
                                free(fname);
                                return false;
                        }
                        fname[entry.len] = 0;
                        
                        if (!ops->link((void *) parent, (void *) node, fname)) {
                                ops->destroy((void *) node);
                                free(fname);
                                return false;
                        }
                        free(fname);
                        
                        if (!tmpfs_blockread(phone, block, bufpos, buflen, pos,
                            &size, sizeof(size)))
                                return false;
                        
                        size = uint32_t_le2host(size);
                        
                        node->data = malloc(size);
                        if (node->data == NULL)
                                return false;
                        
                        node->size = size;
                        if (!tmpfs_blockread(phone, block, bufpos, buflen, pos,
                            node->data, size))
                                return false;
                        
                        break;
                case TMPFS_DIRECTORY:
                        fname = malloc(entry.len + 1);
                        if (fname == NULL)
                                return false;
                        
                        node = (tmpfs_dentry_t *) ops->create(L_DIRECTORY);
                        if (node == NULL) {
                                free(fname);
                                return false;
                        }
                        
                        if (!tmpfs_blockread(phone, block, bufpos, buflen, pos,
                            fname, entry.len)) {
                                ops->destroy((void *) node);
                                free(fname);
                                return false;
                        }
                        fname[entry.len] = 0;
                        
                        if (!ops->link((void *) parent, (void *) node, fname)) {
                                ops->destroy((void *) node);
                                free(fname);
                                return false;
                        }
                        free(fname);
                        
                        if (!tmpfs_restore_recursion(phone, block, bufpos,
                            buflen, pos, node))
                                return false;
                        
                        break;
                default:
                        return false;
                }
        } while (entry.type != TMPFS_NONE);
        
        return true;
}

bool tmpfs_restore(dev_handle_t dev)
{
        libfs_ops_t *ops = &tmpfs_libfs_ops;

        void *block = mmap(NULL, BLOCK_SIZE,
            PROTO_READ | PROTO_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
        
        if (block == NULL)
                return false;
        
        int phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,
            DEVMAP_CONNECT_TO_DEVICE, dev);

        if (phone < 0) {
                munmap(block, BLOCK_SIZE);
                return false;
        }
        
        if (ipc_share_out_start(phone, block, AS_AREA_READ | AS_AREA_WRITE) !=
            EOK)
                goto error;
        
        size_t bufpos = 0;
        size_t buflen = 0;
        size_t pos = 0;
        
        char tag[6];
        if (!tmpfs_blockread(phone, block, &bufpos, &buflen, &pos, tag, 5))
                goto error;
        
        tag[5] = 0;
        if (strcmp(tag, "TMPFS") != 0)
                goto error;
        
        if (!tmpfs_restore_recursion(phone, block, &bufpos, &buflen, &pos,
            ops->root_get(dev)))
                goto error;
                
        ipc_hangup(phone);
        munmap(block, BLOCK_SIZE);
        return true;
        
error:
        ipc_hangup(phone);
        munmap(block, BLOCK_SIZE);
        return false;
}

/**
 * @}
 */