Index: uspace/lib/ext2/Makefile =================================================================== --- uspace/lib/ext2/Makefile (revision 1d6f507f0b213da5fe9346663a8a45869e166812) +++ uspace/lib/ext2/Makefile (revision d241aae2bcae062a85266628d2e2c611d2dee48a) @@ -36,5 +36,6 @@ SOURCES = \ libext2_filesystem.c \ - libext2_superblock.c + libext2_superblock.c \ + libext2_block_group.c include $(USPACE_PREFIX)/Makefile.common Index: uspace/lib/ext2/libext2.h =================================================================== --- uspace/lib/ext2/libext2.h (revision 1d6f507f0b213da5fe9346663a8a45869e166812) +++ uspace/lib/ext2/libext2.h (revision d241aae2bcae062a85266628d2e2c611d2dee48a) @@ -38,4 +38,5 @@ #include "libext2_superblock.h" +#include "libext2_block_group.h" #include "libext2_filesystem.h" Index: uspace/lib/ext2/libext2_block_group.c =================================================================== --- uspace/lib/ext2/libext2_block_group.c (revision d241aae2bcae062a85266628d2e2c611d2dee48a) +++ uspace/lib/ext2/libext2_block_group.c (revision d241aae2bcae062a85266628d2e2c611d2dee48a) @@ -0,0 +1,102 @@ +/* + * Copyright (c) 2011 Martin Sucha + * 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 libext2 + * @{ + */ +/** + * @file + */ + +#include "libext2.h" +#include "libext2_block_group.h" +#include + +/** + * Get block ID corresponding to the block bitmap of this block group + * + * @param bg pointer to block group descriptor + */ +inline uint32_t ext2_block_group_get_block_bitmap_block(ext2_block_group_t *bg) +{ + return uint32_t_le2host(bg->block_bitmap_block); +} + +/** + * Get block ID corresponding to the inode bitmap of this block group + * + * @param bg pointer to block group descriptor + */ +inline uint32_t ext2_block_group_get_inode_bitmap_block(ext2_block_group_t *bg) +{ + return uint32_t_le2host(bg->inode_bitmap_block); +} + +/** + * Get block ID of first block in inode table + * + * @param bg pointer to block group descriptor + */ +inline uint32_t ext2_block_group_get_inode_table_first_block(ext2_block_group_t *bg) +{ + return uint32_t_le2host(bg->inode_table_first_block); +} + +/** + * Get amount of free blocks in this block group + * + * @param bg pointer to block group descriptor + */ +inline uint16_t ext2_block_group_get_free_block_count(ext2_block_group_t *bg) +{ + return uint16_t_le2host(bg->free_block_count); +} + +/** + * Get amount of free inodes in this block group + * + * @param bg pointer to block group descriptor + */ +inline uint16_t ext2_block_group_get_free_inode_count(ext2_block_group_t *bg) +{ + return uint16_t_le2host(bg->free_inode_count); +} + +/** + * Get amount of inodes allocated for directories + * + * @param bg pointer to block group descriptor + */ +inline uint16_t ext2_block_group_get_directory_inode_count(ext2_block_group_t *bg) +{ + return uint16_t_le2host(bg->directory_inode_count); +} + + +/** @} + */ Index: uspace/lib/ext2/libext2_block_group.h =================================================================== --- uspace/lib/ext2/libext2_block_group.h (revision d241aae2bcae062a85266628d2e2c611d2dee48a) +++ uspace/lib/ext2/libext2_block_group.h (revision d241aae2bcae062a85266628d2e2c611d2dee48a) @@ -0,0 +1,67 @@ +/* + * Copyright (c) 2011 Martin Sucha + * 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 libext2 + * @{ + */ +/** + * @file + */ + +#ifndef LIBEXT2_LIBEXT2_BLOCK_GROUP_H_ +#define LIBEXT2_LIBEXT2_BLOCK_GROUP_H_ + +#include + +typedef struct ext2_block_group { + uint32_t block_bitmap_block; // Block ID for block bitmap + uint32_t inode_bitmap_block; // Block ID for inode bitmap + uint32_t inode_table_first_block; // Block ID of first block of inode table + uint16_t free_block_count; // Count of free blocks + uint16_t free_inode_count; // Count of free inodes + uint16_t directory_inode_count; // Number of inodes allocated to directories +} ext2_block_group_t; + +typedef struct ext2_block_group_ref { + block_t *block; // Reference to a block containing this block group descr + ext2_block_group_t *block_group; +} ext2_block_group_ref_t; + +#define EXT2_BLOCK_GROUP_DESCRIPTOR_SIZE 32 + +inline uint32_t ext2_block_group_get_block_bitmap_block(ext2_block_group_t *); +inline uint32_t ext2_block_group_get_inode_bitmap_block(ext2_block_group_t *); +inline uint32_t ext2_block_group_get_inode_table_first_block(ext2_block_group_t *); +inline uint16_t ext2_block_group_get_free_block_count(ext2_block_group_t *); +inline uint16_t ext2_block_group_get_free_inode_count(ext2_block_group_t *); +inline uint16_t ext2_block_group_get_directory_inode_count(ext2_block_group_t *); + +#endif + +/** @} + */ Index: uspace/lib/ext2/libext2_filesystem.c =================================================================== --- uspace/lib/ext2/libext2_filesystem.c (revision 1d6f507f0b213da5fe9346663a8a45869e166812) +++ uspace/lib/ext2/libext2_filesystem.c (revision d241aae2bcae062a85266628d2e2c611d2dee48a) @@ -34,5 +34,7 @@ */ -#include "libext2.h" +#include "libext2_filesystem.h" +#include "libext2_superblock.h" +#include "libext2_block_group.h" #include #include @@ -105,4 +107,67 @@ /** + * Get a reference to block descriptor + * + * @param fs Pointer to filesystem information + * @param bgid Index of block group to find + * @param ref Pointer where to store pointer to block group reference + * + * @return EOK on success or negative error code on failure + */ +int ext2_filesystem_get_block_group_ref(ext2_filesystem_t *fs, uint32_t bgid, + ext2_block_group_ref_t **ref) +{ + int rc; + aoff64_t block_id; + uint32_t descriptors_per_block; + size_t offset; + ext2_block_group_ref_t *newref; + + newref = malloc(sizeof(ext2_block_group_ref_t)); + if (newref == NULL) { + return ENOMEM; + } + + descriptors_per_block = ext2_superblock_get_block_size(fs->superblock) + / EXT2_BLOCK_GROUP_DESCRIPTOR_SIZE; + + // Block group descriptor table starts at the next block after superblock + block_id = ext2_superblock_get_first_block(fs->superblock) + 1; + + // Find the block containing the descriptor we are looking for + block_id += bgid / descriptors_per_block; + offset = (bgid % descriptors_per_block) * EXT2_BLOCK_GROUP_DESCRIPTOR_SIZE; + + rc = block_get(&newref->block, fs->device, block_id, 0); + if (rc != EOK) { + free(newref); + return rc; + } + + newref->block_group = newref->block->data + offset; + + *ref = newref; + + return EOK; +} + +/** + * Free a reference to block group + * + * @param ref Pointer to block group reference to free + * + * @return EOK on success or negative error code on failure + */ +int ext2_filesystem_put_block_group_ref(ext2_block_group_ref_t *ref) +{ + int rc; + + rc = block_put(ref->block); + free(ref); + + return rc; +} + +/** * Finalize an instance of filesystem * Index: uspace/lib/ext2/libext2_filesystem.h =================================================================== --- uspace/lib/ext2/libext2_filesystem.h (revision 1d6f507f0b213da5fe9346663a8a45869e166812) +++ uspace/lib/ext2/libext2_filesystem.h (revision d241aae2bcae062a85266628d2e2c611d2dee48a) @@ -39,4 +39,5 @@ #include #include "libext2_superblock.h" +#include "libext2_block_group.h" typedef struct ext2_filesystem { @@ -52,4 +53,7 @@ extern int ext2_filesystem_init(ext2_filesystem_t *, devmap_handle_t); extern int ext2_filesystem_check_sanity(ext2_filesystem_t *); +extern int ext2_filesystem_get_block_group_ref(ext2_filesystem_t *, uint32_t, + ext2_block_group_ref_t **); +extern int ext2_filesystem_put_block_group_ref(ext2_block_group_ref_t *); extern void ext2_filesystem_fini(ext2_filesystem_t *); Index: uspace/lib/ext2/libext2_superblock.c =================================================================== --- uspace/lib/ext2/libext2_superblock.c (revision 1d6f507f0b213da5fe9346663a8a45869e166812) +++ uspace/lib/ext2/libext2_superblock.c (revision d241aae2bcae062a85266628d2e2c611d2dee48a) @@ -260,10 +260,31 @@ * Compute count of block groups present in the filesystem * + * Note: This function works only for correct filesystem, + * i.e. it assumes that total block count > 0 and + * blocks per group > 0 + * + * Example: + * If there are 3 blocks per group, the result should be as follows: + * Total blocks Result + * 1 1 + * 2 1 + * 3 1 + * 4 2 + * + * * @param sb pointer to superblock */ inline uint32_t ext2_superblock_get_block_group_count(ext2_superblock_t *sb) { - return ext2_superblock_get_total_block_count(sb) / - ext2_superblock_get_blocks_per_group(sb); + /* We add one to the result because e.g. 2/3 = 0, while to store + * 2 blocks in 3-block group we need one (1) block group + * + * We subtract one first because of special case that to store e.g. + * 3 blocks in a 3-block group we need only one group + * (and 3/3 yields one - this is one more that we want as we + * already add one at the end) + */ + return ((ext2_superblock_get_total_block_count(sb)-1) / + ext2_superblock_get_blocks_per_group(sb))+1; }