[36bca8eb] | 1 | /*
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| 2 | * Copyright (c) 2011 Martin Sucha
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| 3 | * All rights reserved.
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| 4 | *
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| 5 | * Redistribution and use in source and binary forms, with or without
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| 6 | * modification, are permitted provided that the following conditions
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| 7 | * are met:
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| 8 | *
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| 9 | * - Redistributions of source code must retain the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer.
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| 11 | * - Redistributions in binary form must reproduce the above copyright
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| 12 | * notice, this list of conditions and the following disclaimer in the
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| 13 | * documentation and/or other materials provided with the distribution.
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| 14 | * - The name of the author may not be used to endorse or promote products
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| 15 | * derived from this software without specific prior written permission.
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| 16 | *
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | */
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| 28 |
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| 29 | /** @addtogroup libext2
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| 30 | * @{
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| 31 | */
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| 32 | /**
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| 33 | * @file
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| 34 | */
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| 35 |
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[d241aae] | 36 | #include "libext2_filesystem.h"
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| 37 | #include "libext2_superblock.h"
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| 38 | #include "libext2_block_group.h"
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[ce13577] | 39 | #include "libext2_inode.h"
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[36bca8eb] | 40 | #include <errno.h>
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| 41 | #include <libblock.h>
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| 42 | #include <malloc.h>
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| 43 |
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| 44 | /**
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| 45 | * Initialize an instance of filesystem on the device.
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| 46 | * This function reads superblock from the device and
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| 47 | * initializes libblock cache with appropriate logical block size.
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[566c401] | 48 | *
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[8bd5dad] | 49 | * @param fs Pointer to ext2_filesystem_t to initialize
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| 50 | * @param devmap_handle Device handle of the block device
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[1d6f507] | 51 | *
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| 52 | * @return EOK on success or negative error code on failure
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[36bca8eb] | 53 | */
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[566c401] | 54 | int ext2_filesystem_init(ext2_filesystem_t *fs, devmap_handle_t devmap_handle)
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| 55 | {
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[36bca8eb] | 56 | int rc;
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| 57 | ext2_superblock_t *temp_superblock;
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[8bd5dad] | 58 | size_t block_size;
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[36bca8eb] | 59 |
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[566c401] | 60 | fs->device = devmap_handle;
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[36bca8eb] | 61 |
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| 62 | rc = block_init(fs->device, 2048);
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| 63 | if (rc != EOK) {
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| 64 | return rc;
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| 65 | }
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| 66 |
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[566c401] | 67 | rc = ext2_superblock_read_direct(fs->device, &temp_superblock);
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[36bca8eb] | 68 | if (rc != EOK) {
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[566c401] | 69 | block_fini(fs->device);
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[36bca8eb] | 70 | return rc;
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| 71 | }
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| 72 |
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[8bd5dad] | 73 | block_size = ext2_superblock_get_block_size(temp_superblock);
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| 74 |
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| 75 | if (block_size > EXT2_MAX_BLOCK_SIZE) {
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| 76 | block_fini(fs->device);
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| 77 | return ENOTSUP;
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| 78 | }
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| 79 |
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| 80 | rc = block_cache_init(devmap_handle, block_size, 0, CACHE_MODE_WT);
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| 81 | if (rc != EOK) {
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| 82 | block_fini(fs->device);
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| 83 | return rc;
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| 84 | }
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| 85 |
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| 86 | fs->superblock = temp_superblock;
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[36bca8eb] | 87 |
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| 88 | return EOK;
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| 89 | }
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| 90 |
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[1d6f507] | 91 | /**
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| 92 | * Check filesystem for sanity
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| 93 | *
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| 94 | * @param fs Pointer to ext2_filesystem_t to check
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| 95 | * @return EOK on success or negative error code on failure
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| 96 | */
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| 97 | int ext2_filesystem_check_sanity(ext2_filesystem_t *fs)
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| 98 | {
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| 99 | int rc;
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| 100 |
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| 101 | rc = ext2_superblock_check_sanity(fs->superblock);
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| 102 | if (rc != EOK) {
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| 103 | return rc;
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| 104 | }
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| 105 |
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| 106 | return EOK;
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| 107 | }
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| 108 |
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[d241aae] | 109 | /**
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| 110 | * Get a reference to block descriptor
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| 111 | *
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| 112 | * @param fs Pointer to filesystem information
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| 113 | * @param bgid Index of block group to find
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| 114 | * @param ref Pointer where to store pointer to block group reference
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| 115 | *
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| 116 | * @return EOK on success or negative error code on failure
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| 117 | */
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| 118 | int ext2_filesystem_get_block_group_ref(ext2_filesystem_t *fs, uint32_t bgid,
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| 119 | ext2_block_group_ref_t **ref)
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| 120 | {
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| 121 | int rc;
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| 122 | aoff64_t block_id;
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| 123 | uint32_t descriptors_per_block;
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| 124 | size_t offset;
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| 125 | ext2_block_group_ref_t *newref;
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| 126 |
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| 127 | newref = malloc(sizeof(ext2_block_group_ref_t));
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| 128 | if (newref == NULL) {
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| 129 | return ENOMEM;
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| 130 | }
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| 131 |
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| 132 | descriptors_per_block = ext2_superblock_get_block_size(fs->superblock)
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| 133 | / EXT2_BLOCK_GROUP_DESCRIPTOR_SIZE;
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| 134 |
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| 135 | // Block group descriptor table starts at the next block after superblock
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| 136 | block_id = ext2_superblock_get_first_block(fs->superblock) + 1;
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| 137 |
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| 138 | // Find the block containing the descriptor we are looking for
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| 139 | block_id += bgid / descriptors_per_block;
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| 140 | offset = (bgid % descriptors_per_block) * EXT2_BLOCK_GROUP_DESCRIPTOR_SIZE;
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| 141 |
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| 142 | rc = block_get(&newref->block, fs->device, block_id, 0);
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| 143 | if (rc != EOK) {
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| 144 | free(newref);
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| 145 | return rc;
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| 146 | }
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| 147 |
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| 148 | newref->block_group = newref->block->data + offset;
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| 149 |
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| 150 | *ref = newref;
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| 151 |
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| 152 | return EOK;
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| 153 | }
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| 154 |
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| 155 | /**
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| 156 | * Free a reference to block group
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| 157 | *
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| 158 | * @param ref Pointer to block group reference to free
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| 159 | *
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| 160 | * @return EOK on success or negative error code on failure
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| 161 | */
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| 162 | int ext2_filesystem_put_block_group_ref(ext2_block_group_ref_t *ref)
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| 163 | {
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| 164 | int rc;
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| 165 |
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| 166 | rc = block_put(ref->block);
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| 167 | free(ref);
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| 168 |
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| 169 | return rc;
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| 170 | }
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| 171 |
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[ce13577] | 172 | /**
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| 173 | * Get a reference to inode
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| 174 | *
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| 175 | * @param fs Pointer to filesystem information
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| 176 | * @param index The index number of the inode
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| 177 | * @param ref Pointer where to store pointer to inode reference
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| 178 | *
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| 179 | * @return EOK on success or negative error code on failure
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| 180 | */
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| 181 | int ext2_filesystem_get_inode_ref(ext2_filesystem_t *fs, uint32_t index,
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| 182 | ext2_inode_ref_t **ref)
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| 183 | {
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| 184 | int rc;
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| 185 | aoff64_t block_id;
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| 186 | uint32_t block_group;
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| 187 | uint32_t offset_in_group;
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[a2a1792] | 188 | uint32_t byte_offset_in_group;
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| 189 | size_t offset_in_block;
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[ce13577] | 190 | uint32_t inodes_per_group;
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| 191 | uint32_t inode_table_start;
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| 192 | uint16_t inode_size;
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| 193 | uint32_t block_size;
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| 194 | ext2_block_group_ref_t *bg_ref;
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| 195 | ext2_inode_ref_t *newref;
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| 196 |
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| 197 | newref = malloc(sizeof(ext2_inode_ref_t));
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| 198 | if (newref == NULL) {
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| 199 | return ENOMEM;
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| 200 | }
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| 201 |
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| 202 | inodes_per_group = ext2_superblock_get_inodes_per_group(fs->superblock);
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| 203 |
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| 204 | // inode numbers are 1-based
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| 205 | index -= 1;
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| 206 | block_group = index / inodes_per_group;
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| 207 | offset_in_group = index % inodes_per_group;
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| 208 |
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| 209 | rc = ext2_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
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| 210 | if (rc != EOK) {
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| 211 | free(newref);
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| 212 | return rc;
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| 213 | }
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| 214 |
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| 215 | inode_table_start = ext2_block_group_get_inode_table_first_block(
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| 216 | bg_ref->block_group);
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| 217 |
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| 218 | inode_size = ext2_superblock_get_inode_size(fs->superblock);
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| 219 | block_size = ext2_superblock_get_block_size(fs->superblock);
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| 220 |
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[a2a1792] | 221 | byte_offset_in_group = offset_in_group * inode_size;
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| 222 |
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| 223 | block_id = inode_table_start + (byte_offset_in_group / block_size);
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| 224 | offset_in_block = byte_offset_in_group % block_size;
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[ce13577] | 225 |
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| 226 | rc = block_get(&newref->block, fs->device, block_id, 0);
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| 227 | if (rc != EOK) {
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| 228 | free(newref);
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| 229 | return rc;
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| 230 | }
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| 231 |
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[a2a1792] | 232 | newref->inode = newref->block->data + offset_in_block;
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[ce13577] | 233 |
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| 234 | *ref = newref;
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| 235 |
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| 236 | return EOK;
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| 237 | }
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| 238 |
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| 239 | /**
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| 240 | * Free a reference to inode
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| 241 | *
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| 242 | * @param ref Pointer to inode reference to free
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| 243 | *
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| 244 | * @return EOK on success or negative error code on failure
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| 245 | */
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| 246 | int ext2_filesystem_put_inode_ref(ext2_inode_ref_t *ref)
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| 247 | {
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| 248 | int rc;
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| 249 |
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| 250 | rc = block_put(ref->block);
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| 251 | free(ref);
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| 252 |
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| 253 | return rc;
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| 254 | }
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| 255 |
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[36bca8eb] | 256 | /**
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| 257 | * Finalize an instance of filesystem
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[566c401] | 258 | *
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| 259 | * @param fs Pointer to ext2_filesystem_t to finalize
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[36bca8eb] | 260 | */
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[566c401] | 261 | void ext2_filesystem_fini(ext2_filesystem_t *fs)
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| 262 | {
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[8bd5dad] | 263 | free(fs->superblock);
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[36bca8eb] | 264 | block_fini(fs->device);
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| 265 | }
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| 266 |
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| 267 |
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| 268 | /** @}
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| 269 | */
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