source: mainline/uspace/lib/ext4/libext4_inode.c@ b12ca16

/*
 * Copyright (c) 2011 Frantisek Princ
 * 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 libext4
 * @{
 */ 

/**
 * @file        libext4_inode.c
 * @brief       Ext4 inode structure operations.
 */

#include <byteorder.h>
#include <errno.h>
#include <libblock.h>
#include "libext4.h"

static uint32_t ext4_inode_block_bits_count(uint32_t block_size)
{
        uint32_t bits = 8;
        uint32_t size = block_size;

        do {
                bits++;
                size = size >> 1;
        } while (size > 256);

        return bits;
}

uint32_t ext4_inode_get_mode(ext4_superblock_t *sb, ext4_inode_t *inode)
{
        if (ext4_superblock_get_creator_os(sb) == EXT4_SUPERBLOCK_OS_HURD) {
                return ((uint32_t)uint16_t_le2host(inode->osd2.hurd2.mode_high)) << 16 |
                    ((uint32_t)uint16_t_le2host(inode->mode));
        }
        return uint16_t_le2host(inode->mode);
}

bool ext4_inode_is_type(ext4_superblock_t *sb, ext4_inode_t *inode, uint32_t type)
{
        uint32_t mode = ext4_inode_get_mode(sb, inode);
        return (mode & EXT4_INODE_MODE_TYPE_MASK) == type;
}

/*
uint32_t ext4_inode_get_uid(ext4_inode_t *inode)
*/

uint64_t ext4_inode_get_size(ext4_superblock_t *sb, ext4_inode_t *inode)
{
        uint32_t major_rev = ext4_superblock_get_rev_level(sb);

        if ((major_rev > 0) && ext4_inode_is_type(sb, inode, EXT4_INODE_MODE_FILE)) {
                return ((uint64_t)uint32_t_le2host(inode->size_hi)) << 32 |
                            ((uint64_t)uint32_t_le2host(inode->size_lo));
        }
        return uint32_t_le2host(inode->size_lo);
}

void ext4_inode_set_size(ext4_inode_t *inode, uint64_t value) {
        inode->size_lo = host2uint32_t_le((value << 32) >> 32);
        inode->size_hi = host2uint32_t_le(value >> 32);
}

/*
extern uint32_t ext4_inode_get_access_time(ext4_inode_t *);
extern uint32_t ext4_inode_get_change_inode_time(ext4_inode_t *);
extern uint32_t ext4_inode_get_modification_time(ext4_inode_t *);
extern uint32_t ext4_inode_get_deletion_time(ext4_inode_t *);
extern uint32_t ext4_inode_get_gid(ext4_inode_t *);
*/

uint16_t ext4_inode_get_links_count(ext4_inode_t *inode)
{
        return uint16_t_le2host(inode->links_count);
}


uint64_t ext4_inode_get_blocks_count(ext4_superblock_t *sb, ext4_inode_t *inode)
{
        uint64_t count;

        if (ext4_superblock_has_feature_read_only(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {

                /* 48-bit field */
                count = ((uint64_t)uint16_t_le2host(inode->osd2.linux2.blocks_high)) << 32 |
                                uint32_t_le2host(inode->blocks_count_lo);

                if (ext4_inode_has_flag(inode, EXT4_INODE_FLAG_HUGE_FILE)) {
                uint32_t block_size = ext4_superblock_get_block_size(sb);
                uint32_t block_bits = ext4_inode_block_bits_count(block_size);
                        return count  << (block_bits - 9);
                } else {
                        return count;
                }
        } else {
                return uint32_t_le2host(inode->blocks_count_lo);
    }

}

int ext4_inode_set_blocks_count(ext4_superblock_t *sb, ext4_inode_t *inode,
                uint64_t count)
{
    // 32-bit maximum
    uint64_t max = 0;
    max = ~max >> 32;

    if (count <= max) {
        inode->blocks_count_lo = host2uint32_t_le(count);
        inode->osd2.linux2.blocks_high = 0;
        ext4_inode_clear_flag(inode, EXT4_INODE_FLAG_HUGE_FILE);
        return EOK;
    }

    if (!ext4_superblock_has_feature_read_only(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
        return EINVAL;
    }

    // 48-bit maximum
    max = 0;
    max = ~max >> 16;

    if (count <= max) {
        inode->blocks_count_lo = host2uint32_t_le(count);
        inode->osd2.linux2.blocks_high = host2uint16_t_le(count >> 32);
        ext4_inode_clear_flag(inode, EXT4_INODE_FLAG_HUGE_FILE);
    } else {
        uint32_t block_size = ext4_superblock_get_block_size(sb);
        uint32_t block_bits = ext4_inode_block_bits_count(block_size);
        ext4_inode_set_flag(inode, EXT4_INODE_FLAG_HUGE_FILE);
        count = count >> (block_bits - 9);
        inode->blocks_count_lo = host2uint32_t_le(count);
        inode->osd2.linux2.blocks_high = host2uint16_t_le(count >> 32);
    }
    return EOK;


}

uint32_t ext4_inode_get_flags(ext4_inode_t *inode) {
        return uint32_t_le2host(inode->flags);
}

void ext4_inode_set_flags(ext4_inode_t *inode, uint32_t flags) {
        inode->flags = host2uint32_t_le(flags);
}

uint32_t ext4_inode_get_direct_block(ext4_inode_t *inode, uint32_t idx)
{
        assert(idx < EXT4_INODE_DIRECT_BLOCK_COUNT);
        return uint32_t_le2host(inode->blocks[idx]);
}

void ext4_inode_set_direct_block(ext4_inode_t *inode, uint32_t idx, uint32_t fblock)
{
        assert(idx < EXT4_INODE_DIRECT_BLOCK_COUNT);
        inode->blocks[idx] = host2uint32_t_le(fblock);
}

uint32_t ext4_inode_get_indirect_block(ext4_inode_t *inode, uint32_t idx)
{
        return uint32_t_le2host(inode->blocks[idx + EXT4_INODE_INDIRECT_BLOCK]);
}

void ext4_inode_set_indirect_block(ext4_inode_t *inode, uint32_t idx, uint32_t fblock)
{
        inode->blocks[idx + EXT4_INODE_INDIRECT_BLOCK] = host2uint32_t_le(fblock);
}


uint32_t ext4_inode_get_extent_block(ext4_inode_t *inode, uint64_t idx, service_id_t service_id)
{
        ext4_extent_header_t *header = ext4_inode_get_extent_header(inode);
        ext4_extent_t *extent;
        ext4_extent_index_t *extent_index;

        uint32_t first_block;
        uint16_t block_count;
        uint64_t phys_block = 0;
        uint64_t child;

        int rc;
        block_t* block = NULL;

        while (ext4_extent_header_get_depth(header) != 0) {

                extent_index = EXT4_EXTENT_FIRST_INDEX(header);

                for (uint16_t i = 0; i < ext4_extent_header_get_entries_count(header); ++i) {
                        if(idx >= ext4_extent_index_get_first_block(extent_index)) {

                                child = ext4_extent_index_get_leaf(extent_index);

                                if (block != NULL) {
                                        block_put(block);
                                }

                                rc = block_get(&block, service_id, child, BLOCK_FLAGS_NONE);
                                if (rc != EOK) {
                                        return 0;
                                }

                                header = (ext4_extent_header_t *)block->data;
                                break;
                        }
                }
        }

        extent = EXT4_EXTENT_FIRST(header);

        for (uint16_t i = 0; i < ext4_extent_header_get_entries_count(header); ++i) {

                first_block = ext4_extent_get_first_block(extent);
                block_count = ext4_extent_get_block_count(extent);

                if ((idx >= first_block) && (idx < first_block + block_count)) {
                        phys_block = ext4_extent_get_start(extent) + idx;
                        phys_block -= ext4_extent_get_first_block(extent);

                        // Memory leak prevention
                        if (block != NULL) {
                                block_put(block);
                        }
                        return phys_block;
                }
                // Go to the next extent
                ++extent;
        }


        EXT4FS_DBG("ERROR - reached function end");
        return phys_block;
}

ext4_extent_header_t * ext4_inode_get_extent_header(ext4_inode_t *inode)
{
        return (ext4_extent_header_t *)inode->blocks;
}

// Flags operations
bool ext4_inode_has_flag(ext4_inode_t *inode, uint32_t flag)
{
        if (ext4_inode_get_flags(inode) & flag) {
                return true;
        }
        return false;
}

void ext4_inode_clear_flag(ext4_inode_t *inode, uint32_t clear_flag)
{
        uint32_t flags = ext4_inode_get_flags(inode);
        flags = flags & (~clear_flag);
        ext4_inode_set_flags(inode, flags);
}

void ext4_inode_set_flag(ext4_inode_t *inode, uint32_t set_flag)
{
        uint32_t flags = ext4_inode_get_flags(inode);
        flags = flags | set_flag;
        ext4_inode_set_flags(inode, flags);
}

bool ext4_inode_can_truncate(ext4_superblock_t *sb, ext4_inode_t *inode)
{
         if (ext4_inode_has_flag(inode, EXT4_INODE_FLAG_APPEND)
                         || ext4_inode_has_flag(inode, EXT4_INODE_FLAG_IMMUTABLE)) {
                 return false;
         }

         if (ext4_inode_is_type(sb, inode, EXT4_INODE_MODE_FILE)
                         || ext4_inode_is_type(sb, inode, EXT4_INODE_MODE_DIRECTORY)) {
                 return true;
         }

         return false;
}

/**
 * @}
 */