tmpfs_dump.c

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/*
 * 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.
 */

#include "tmpfs.h"
#include "../../vfs/vfs.h"
#include <errno.h>
#include <stdlib.h>
#include <str.h>
#include <sys/types.h>
#include <as.h>
#include <libblock.h>
#include <byteorder.h>

#define TMPFS_COMM_SIZE         1024

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

static bool
tmpfs_restore_recursion(devmap_handle_t dev, size_t *bufpos, size_t *buflen,
    aoff64_t *pos, fs_node_t *pfn)
{
        struct rdentry entry;
        libfs_ops_t *ops = &tmpfs_libfs_ops;
        int rc;
        
        do {
                char *fname;
                fs_node_t *fn;
                tmpfs_node_t *nodep;
                uint32_t size;
                
                if (block_seqread(dev, bufpos, buflen, pos, &entry,
                    sizeof(entry)) != EOK)
                        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;
                        
                        rc = ops->create(&fn, dev, L_FILE);
                        if (rc != EOK || fn == NULL) {
                                free(fname);
                                return false;
                        }
                        
                        if (block_seqread(dev, bufpos, buflen, pos, fname,
                            entry.len) != EOK) {
                                (void) ops->destroy(fn);
                                free(fname);
                                return false;
                        }
                        fname[entry.len] = 0;
                        
                        rc = ops->link(pfn, fn, fname);
                        if (rc != EOK) {
                                (void) ops->destroy(fn);
                                free(fname);
                                return false;
                        }
                        free(fname);
                        
                        if (block_seqread(dev, bufpos, buflen, pos, &size,
                            sizeof(size)) != EOK)
                                return false;
                        
                        size = uint32_t_le2host(size);
                        
                        nodep = TMPFS_NODE(fn);
                        nodep->data = malloc(size);
                        if (nodep->data == NULL)
                                return false;
                        
                        nodep->size = size;
                        if (block_seqread(dev, bufpos, buflen, pos, nodep->data,
                            size) != EOK)
                                return false;
                        
                        break;
                case TMPFS_DIRECTORY:
                        fname = malloc(entry.len + 1);
                        if (fname == NULL)
                                return false;
                        
                        rc = ops->create(&fn, dev, L_DIRECTORY);
                        if (rc != EOK || fn == NULL) {
                                free(fname);
                                return false;
                        }
                        
                        if (block_seqread(dev, bufpos, buflen, pos, fname,
                            entry.len) != EOK) {
                                (void) ops->destroy(fn);
                                free(fname);
                                return false;
                        }
                        fname[entry.len] = 0;

                        rc = ops->link(pfn, fn, fname);
                        if (rc != EOK) {
                                (void) ops->destroy(fn);
                                free(fname);
                                return false;
                        }
                        free(fname);
                        
                        if (!tmpfs_restore_recursion(dev, bufpos, buflen, pos,
                            fn))
                                return false;
                        
                        break;
                default:
                        return false;
                }
        } while (entry.type != TMPFS_NONE);
        
        return true;
}

bool tmpfs_restore(devmap_handle_t dev)
{
        libfs_ops_t *ops = &tmpfs_libfs_ops;
        fs_node_t *fn;
        int rc;

        rc = block_init(dev, TMPFS_COMM_SIZE);
        if (rc != EOK)
                return false; 
        
        size_t bufpos = 0;
        size_t buflen = 0;
        aoff64_t pos = 0;
        
        char tag[6];
        if (block_seqread(dev, &bufpos, &buflen, &pos, tag, 5) != EOK)
                goto error;
        
        tag[5] = 0;
        if (str_cmp(tag, "TMPFS") != 0)
                goto error;
        
        rc = ops->root_get(&fn, dev);
        if (rc != EOK)
                goto error;

        if (!tmpfs_restore_recursion(dev, &bufpos, &buflen, &pos, fn))
                goto error;
                
        block_fini(dev);
        return true;
        
error:
        block_fini(dev);
        return false;
}

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