Index: uspace/lib/ext2/libext2_filesystem.c =================================================================== --- uspace/lib/ext2/libext2_filesystem.c (revision a54af668b195587f801880c219d838ca1c5537fe) +++ uspace/lib/ext2/libext2_filesystem.c (revision ad34feb47f3ea02025abdcc9a3565f7e7df1ec6a) @@ -41,4 +41,5 @@ #include #include +#include /** @@ -255,4 +256,94 @@ /** + * Find a filesystem block number where iblock-th data block + * of the given inode is located. + * + * @return EOK on success or negative error code on failure + */ +int ext2_filesystem_get_inode_data_block_index(ext2_filesystem_t *fs, ext2_inode_t* inode, + aoff64_t iblock, uint32_t* fblock) +{ + int rc; + aoff64_t limits[4]; + uint32_t block_ids_per_block; + aoff64_t blocks_per_level[4]; + uint32_t offset_in_block; + uint32_t current_block; + aoff64_t block_offset_in_level; + int i; + int level; + block_t *block; + + if (iblock < EXT2_INODE_DIRECT_BLOCKS) { + current_block = ext2_inode_get_direct_block(inode, (uint32_t)iblock); + if (current_block == 0) { + return EIO; + } + *fblock = current_block; + return EOK; + } + + // Compute limits for indirect block levels + // TODO: compute this once when loading filesystem and store in ext2_filesystem_t + block_ids_per_block = ext2_superblock_get_block_size(fs->superblock) / sizeof(uint32_t); + limits[0] = EXT2_INODE_DIRECT_BLOCKS; + blocks_per_level[0] = 1; + for (i = 1; i < 4; i++) { + blocks_per_level[i] = blocks_per_level[i-1] * + block_ids_per_block; + limits[i] = limits[i-1] + blocks_per_level[i]; + } + + // Determine the indirection level needed to get the desired block + level = -1; + for (i = 1; i < 4; i++) { + if (iblock < limits[i]) { + level = i; + break; + } + } + + if (level == -1) { + return EIO; + } + + block_offset_in_level = iblock - limits[level-1]; + current_block = ext2_inode_get_indirect_block(inode, level-1); + offset_in_block = block_offset_in_level / blocks_per_level[level-1]; + + while (level > 0) { + rc = block_get(&block, fs->device, current_block, 0); + if (rc != EOK) { + return rc; + } + + assert(offset_in_block < block_ids_per_block); + current_block = ((uint32_t*)block->data)[offset_in_block]; + + rc = block_put(block); + if (rc != EOK) { + return rc; + } + + if (current_block == 0) { + return EIO; + } + + level -= 1; + + if (level == 0) { + break; + } + + offset_in_block = block_offset_in_level / blocks_per_level[level-1]; + block_offset_in_level %= blocks_per_level[level-1]; + } + + *fblock = current_block; + + return EOK; +} + +/** * Finalize an instance of filesystem * Index: uspace/lib/ext2/libext2_filesystem.h =================================================================== --- uspace/lib/ext2/libext2_filesystem.h (revision a54af668b195587f801880c219d838ca1c5537fe) +++ uspace/lib/ext2/libext2_filesystem.h (revision ad34feb47f3ea02025abdcc9a3565f7e7df1ec6a) @@ -60,4 +60,6 @@ ext2_inode_ref_t **); extern int ext2_filesystem_put_inode_ref(ext2_inode_ref_t *); +extern int ext2_filesystem_get_inode_data_block_index(ext2_filesystem_t *, ext2_inode_t*, + aoff64_t, uint32_t*); extern void ext2_filesystem_fini(ext2_filesystem_t *); Index: uspace/lib/ext2/libext2_inode.c =================================================================== --- uspace/lib/ext2/libext2_inode.c (revision a54af668b195587f801880c219d838ca1c5537fe) +++ uspace/lib/ext2/libext2_inode.c (revision ad34feb47f3ea02025abdcc9a3565f7e7df1ec6a) @@ -38,4 +38,5 @@ #include "libext2_superblock.h" #include +#include /** @@ -142,4 +143,17 @@ /** + * Get number of blocks allocated for contents of the file + * represented by this inode. + * + * @param inode pointer to inode + */ +inline uint32_t ext2_inode_get_reserved_blocks(ext2_superblock_t *sb, + ext2_inode_t *inode) +{ + return ext2_inode_get_reserved_512_blocks(inode) / + (ext2_superblock_get_block_size(sb) / 512); +} + +/** * Get inode flags * @@ -158,4 +172,5 @@ inline uint32_t ext2_inode_get_direct_block(ext2_inode_t *inode, uint8_t idx) { + assert(idx < EXT2_INODE_DIRECT_BLOCKS); return uint32_t_le2host(inode->direct_blocks[idx]); } @@ -165,31 +180,12 @@ * * @param inode pointer to inode + * @param idx Indirection level. Valid values are 0 <= idx < 3, where 0 is + * singly-indirect block and 2 is triply-indirect-block */ -inline uint32_t ext2_inode_get_single_indirect_block(ext2_inode_t *inode) +inline uint32_t ext2_inode_get_indirect_block(ext2_inode_t *inode, uint8_t idx) { - return uint32_t_le2host(inode->single_indirect_block); + assert(idx < 3); + return uint32_t_le2host(inode->indirect_blocks[idx]); } - -/** - * Get double indirect block ID - * - * @param inode pointer to inode - */ -inline uint32_t ext2_inode_get_double_indirect_block(ext2_inode_t *inode) -{ - return uint32_t_le2host(inode->double_indirect_block); -} - -/** - * Get triple indirect block ID - * - * @param inode pointer to inode - */ -inline uint32_t ext2_inode_get_triple_indirect_block(ext2_inode_t *inode) -{ - return uint32_t_le2host(inode->triple_indirect_block); -} - - /** @} Index: uspace/lib/ext2/libext2_inode.h =================================================================== --- uspace/lib/ext2/libext2_inode.h (revision a54af668b195587f801880c219d838ca1c5537fe) +++ uspace/lib/ext2/libext2_inode.h (revision ad34feb47f3ea02025abdcc9a3565f7e7df1ec6a) @@ -51,7 +51,5 @@ uint8_t unused2[4]; uint32_t direct_blocks[12]; // Direct block ids stored in this inode - uint32_t single_indirect_block; - uint32_t double_indirect_block; - uint32_t triple_indirect_block; + uint32_t indirect_blocks[3]; uint32_t version; uint32_t file_acl; @@ -75,4 +73,5 @@ #define EXT2_INODE_MODE_ACCESS_MASK 0x0FFF #define EXT2_INODE_MODE_TYPE_MASK 0xF000 +#define EXT2_INODE_DIRECT_BLOCKS 12 typedef struct ext2_inode_ref { @@ -88,9 +87,9 @@ inline uint16_t ext2_inode_get_usage_count(ext2_inode_t *); inline uint32_t ext2_inode_get_reserved_512_blocks(ext2_inode_t *); +inline uint32_t ext2_inode_get_reserved_blocks(ext2_superblock_t *, + ext2_inode_t *); inline uint32_t ext2_inode_get_flags(ext2_inode_t *); inline uint32_t ext2_inode_get_direct_block(ext2_inode_t *, uint8_t); -inline uint32_t ext2_inode_get_single_indirect_block(ext2_inode_t *); -inline uint32_t ext2_inode_get_double_indirect_block(ext2_inode_t *); -inline uint32_t ext2_inode_get_triple_indirect_block(ext2_inode_t *); +inline uint32_t ext2_inode_get_indirect_block(ext2_inode_t *, uint8_t level);