-/*\r
- * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)\r
- *\r
- *\r
- * HelenOS:\r
- * Copyright (c) 2012 Martin Sucha\r
- * Copyright (c) 2012 Frantisek Princ\r
- * All rights reserved.\r
- *\r
- * Redistribution and use in source and binary forms, with or without\r
- * modification, are permitted provided that the following conditions\r
- * are met:\r
- *\r
- * - Redistributions of source code must retain the above copyright\r
- * notice, this list of conditions and the following disclaimer.\r
- * - Redistributions in binary form must reproduce the above copyright\r
- * notice, this list of conditions and the following disclaimer in the\r
- * documentation and/or other materials provided with the distribution.\r
- * - The name of the author may not be used to endorse or promote products\r
- * derived from this software without specific prior written permission.\r
- *\r
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\r
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES\r
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.\r
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,\r
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT\r
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,\r
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY\r
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT\r
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF\r
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\r
- */\r
-\r
-/** @addtogroup lwext4\r
- * @{\r
- */\r
-/**\r
- * @file ext4_extent.c\r
- * @brief More complex filesystem functions.\r
- */\r
-\r
-#include <ext4_config.h>\r
-#include <ext4_extent.h>\r
-#include <ext4_inode.h>\r
-#include <ext4_super.h>\r
-#include <ext4_blockdev.h>\r
-#include <ext4_balloc.h>\r
-\r
-#include <string.h>\r
-#include <stdlib.h>\r
-\r
-uint32_t ext4_extent_get_first_block(struct ext4_extent *extent)\r
-{\r
- return to_le32(extent->first_block);\r
-}\r
-\r
-\r
-void ext4_extent_set_first_block(struct ext4_extent *extent, uint32_t iblock)\r
-{\r
- extent->first_block = to_le32(iblock);\r
-}\r
-\r
-\r
-uint16_t ext4_extent_get_block_count(struct ext4_extent *extent)\r
-{\r
- return to_le16(extent->block_count);\r
-}\r
-\r
-\r
-void ext4_extent_set_block_count(struct ext4_extent *extent, uint16_t count)\r
-{\r
- extent->block_count = to_le16(count);\r
-}\r
-\r
-\r
-uint64_t ext4_extent_get_start(struct ext4_extent *extent)\r
-{\r
- return ((uint64_t)to_le16(extent->start_hi)) << 32 |\r
- ((uint64_t)to_le32(extent->start_lo));\r
-}\r
-\r
-\r
-void ext4_extent_set_start(struct ext4_extent *extent, uint64_t fblock)\r
-{\r
- extent->start_lo = to_le32((fblock << 32) >> 32);\r
- extent->start_hi = to_le16((uint16_t)(fblock >> 32));\r
-}\r
-\r
-\r
-uint32_t ext4_extent_index_get_first_block(struct ext4_extent_index *index)\r
-{\r
- return to_le32(index->first_block);\r
-}\r
-\r
-\r
-void ext4_extent_index_set_first_block(struct ext4_extent_index *index,\r
- uint32_t iblock)\r
-{\r
- index->first_block = to_le32(iblock);\r
-}\r
-\r
-\r
-uint64_t ext4_extent_index_get_leaf(struct ext4_extent_index *index)\r
-{\r
- return ((uint64_t) to_le16(index->leaf_hi)) << 32 |\r
- ((uint64_t)to_le32(index->leaf_lo));\r
-}\r
-\r
-void ext4_extent_index_set_leaf(struct ext4_extent_index *index,\r
- uint64_t fblock)\r
-{\r
- index->leaf_lo = to_le32((fblock << 32) >> 32);\r
- index->leaf_hi = to_le16((uint16_t) (fblock >> 32));\r
-}\r
-\r
-\r
-uint16_t ext4_extent_header_get_magic(struct ext4_extent_header *header)\r
-{\r
- return to_le16(header->magic);\r
-}\r
-\r
-\r
-void ext4_extent_header_set_magic(struct ext4_extent_header *header,\r
- uint16_t magic)\r
-{\r
- header->magic = to_le16(magic);\r
-}\r
-\r
-\r
-uint16_t ext4_extent_header_get_entries_count(struct ext4_extent_header *header)\r
-{\r
- return to_le16(header->entries_count);\r
-}\r
-\r
-\r
-void ext4_extent_header_set_entries_count(struct ext4_extent_header *header,\r
- uint16_t count)\r
-{\r
- header->entries_count = to_le16(count);\r
-}\r
-\r
-\r
-uint16_t ext4_extent_header_get_max_entries_count(struct ext4_extent_header *header)\r
-{\r
- return to_le16(header->max_entries_count);\r
-}\r
-\r
-\r
-void ext4_extent_header_set_max_entries_count(struct ext4_extent_header *header,\r
- uint16_t max_count)\r
-{\r
- header->max_entries_count = to_le16(max_count);\r
-}\r
-\r
-\r
-uint16_t ext4_extent_header_get_depth(struct ext4_extent_header *header)\r
-{\r
- return to_le16(header->depth);\r
-}\r
-\r
-\r
-void ext4_extent_header_set_depth(struct ext4_extent_header *header,\r
- uint16_t depth)\r
-{\r
- header->depth = to_le16(depth);\r
-}\r
-\r
-\r
-uint32_t ext4_extent_header_get_generation(struct ext4_extent_header *header)\r
-{\r
- return to_le32(header->generation);\r
-}\r
-\r
-\r
-void ext4_extent_header_set_generation(struct ext4_extent_header *header,\r
- uint32_t generation)\r
-{\r
- header->generation = to_le32(generation);\r
-}\r
-\r
-/**@brief Binary search in extent index node.\r
- * @param header Extent header of index node\r
- * @param index Output value - found index will be set here\r
- * @param iblock Logical block number to find in index node */\r
-static void ext4_extent_binsearch_idx(struct ext4_extent_header *header,\r
- struct ext4_extent_index **index, uint32_t iblock)\r
-{\r
- struct ext4_extent_index *r;\r
- struct ext4_extent_index *l;\r
- struct ext4_extent_index *m;\r
-\r
- uint16_t entries_count =\r
- ext4_extent_header_get_entries_count(header);\r
-\r
- /* Initialize bounds */\r
- l = EXT4_EXTENT_FIRST_INDEX(header) + 1;\r
- r = EXT4_EXTENT_FIRST_INDEX(header) + entries_count - 1;\r
-\r
- /* Do binary search */\r
- while (l <= r) {\r
- m = l + (r - l) / 2;\r
- uint32_t first_block = ext4_extent_index_get_first_block(m);\r
-\r
- if (iblock < first_block)\r
- r = m - 1;\r
- else\r
- l = m + 1;\r
- }\r
-\r
- /* Set output value */\r
- *index = l - 1;\r
-}\r
-\r
-/**@brief Binary search in extent leaf node.\r
- * @param header Extent header of leaf node\r
- * @param extent Output value - found extent will be set here,\r
- * or NULL if node is empty\r
- * @param iblock Logical block number to find in leaf node */\r
-static void ext4_extent_binsearch(struct ext4_extent_header *header,\r
- struct ext4_extent **extent, uint32_t iblock)\r
-{\r
- struct ext4_extent *r;\r
- struct ext4_extent *l;\r
- struct ext4_extent *m;\r
-\r
- uint16_t entries_count =\r
- ext4_extent_header_get_entries_count(header);\r
-\r
- if (entries_count == 0) {\r
- /* this leaf is empty */\r
- *extent = NULL;\r
- return;\r
- }\r
-\r
- /* Initialize bounds */\r
- l = EXT4_EXTENT_FIRST(header) + 1;\r
- r = EXT4_EXTENT_FIRST(header) + entries_count - 1;\r
-\r
- /* Do binary search */\r
- while (l <= r) {\r
- m = l + (r - l) / 2;\r
- uint32_t first_block = ext4_extent_get_first_block(m);\r
-\r
- if (iblock < first_block)\r
- r = m - 1;\r
- else\r
- l = m + 1;\r
- }\r
-\r
- /* Set output value */\r
- *extent = l - 1;\r
-}\r
-\r
-\r
-int ext4_extent_find_block(struct ext4_inode_ref *inode_ref, uint32_t iblock,\r
- uint32_t *fblock)\r
-{\r
- /* Compute bound defined by i-node size */\r
- uint64_t inode_size =\r
- ext4_inode_get_size(&inode_ref->fs->sb, inode_ref->inode);\r
-\r
- uint32_t block_size =\r
- ext4_sb_get_block_size(&inode_ref->fs->sb);\r
-\r
- uint32_t last_idx = (inode_size - 1) / block_size;\r
-\r
- /* Check if requested iblock is not over size of i-node */\r
- if (iblock > last_idx) {\r
- *fblock = 0;\r
- return EOK;\r
- }\r
-\r
- struct ext4_block block;\r
- block.lb_id = 0;\r
-\r
- /* Walk through extent tree */\r
- struct ext4_extent_header *header =\r
- ext4_inode_get_extent_header(inode_ref->inode);\r
-\r
- while (ext4_extent_header_get_depth(header) != 0) {\r
- /* Search index in node */\r
- struct ext4_extent_index *index;\r
- ext4_extent_binsearch_idx(header, &index, iblock);\r
-\r
- /* Load child node and set values for the next iteration */\r
- uint64_t child = ext4_extent_index_get_leaf(index);\r
-\r
- if (block.lb_id)\r
- ext4_block_set(inode_ref->fs->bdev, &block);\r
-\r
-\r
- int rc = ext4_block_get(inode_ref->fs->bdev, &block, child);\r
- if (rc != EOK)\r
- return rc;\r
-\r
- header = (struct ext4_extent_header *)block.data;\r
- }\r
-\r
- /* Search extent in the leaf block */\r
- struct ext4_extent* extent = NULL;\r
- ext4_extent_binsearch(header, &extent, iblock);\r
-\r
- /* Prevent empty leaf */\r
- if (extent == NULL) {\r
- *fblock = 0;\r
- } else {\r
- /* Compute requested physical block address */\r
- uint32_t phys_block;\r
- uint32_t first = ext4_extent_get_first_block(extent);\r
- phys_block = ext4_extent_get_start(extent) + iblock - first;\r
-\r
- *fblock = phys_block;\r
- }\r
-\r
- /* Cleanup */\r
- if (block.lb_id)\r
- ext4_block_set(inode_ref->fs->bdev, &block);\r
-\r
- return EOK;\r
-}\r
-\r
-/**@brief Find extent for specified iblock.\r
- * This function is used for finding block in the extent tree with\r
- * saving the path through the tree for possible future modifications.\r
- * @param inode_ref I-node to read extent tree from\r
- * @param iblock Iblock to find extent for\r
- * @param ret_path Output value for loaded path from extent tree\r
- * @return Error code */\r
-static int ext4_extent_find_extent(struct ext4_inode_ref *inode_ref,\r
- uint32_t iblock, struct ext4_extent_path **ret_path)\r
-{\r
- struct ext4_extent_header *eh =\r
- ext4_inode_get_extent_header(inode_ref->inode);\r
-\r
- uint16_t depth = ext4_extent_header_get_depth(eh);\r
- uint16_t i;\r
- struct ext4_extent_path *tmp_path;\r
-\r
- /* Added 2 for possible tree growing */\r
- tmp_path = malloc(sizeof(struct ext4_extent_path) * (depth + 2));\r
- if (tmp_path == NULL)\r
- return ENOMEM;\r
-\r
- /* Initialize structure for algorithm start */\r
- tmp_path[0].block = inode_ref->block;\r
- tmp_path[0].header = eh;\r
-\r
- /* Walk through the extent tree */\r
- uint16_t pos = 0;\r
- int rc;\r
- while (ext4_extent_header_get_depth(eh) != 0) {\r
- /* Search index in index node by iblock */\r
- ext4_extent_binsearch_idx(tmp_path[pos].header,\r
- &tmp_path[pos].index, iblock);\r
-\r
- tmp_path[pos].depth = depth;\r
- tmp_path[pos].extent = NULL;\r
-\r
- ext4_assert(tmp_path[pos].index != 0);\r
-\r
- /* Load information for the next iteration */\r
- uint64_t fblock = ext4_extent_index_get_leaf(tmp_path[pos].index);\r
-\r
- struct ext4_block block;\r
- rc = ext4_block_get(inode_ref->fs->bdev, &block, fblock);\r
- if (rc != EOK)\r
- goto cleanup;\r
-\r
- pos++;\r
-\r
- eh = (struct ext4_extent_header *)block.data;\r
- tmp_path[pos].block = block;\r
- tmp_path[pos].header = eh;\r
- }\r
-\r
- tmp_path[pos].depth = 0;\r
- tmp_path[pos].extent = NULL;\r
- tmp_path[pos].index = NULL;\r
-\r
- /* Find extent in the leaf node */\r
- ext4_extent_binsearch(tmp_path[pos].header, &tmp_path[pos].extent, iblock);\r
- *ret_path = tmp_path;\r
-\r
- return EOK;\r
-\r
-cleanup:\r
- /*\r
- * Put loaded blocks\r
- * From 1: 0 is a block with inode data\r
- */\r
- for (i = 1; i < tmp_path->depth; ++i) {\r
- if (tmp_path[i].block.lb_id)\r
- ext4_block_set(inode_ref->fs->bdev, &tmp_path[i].block);\r
- }\r
-\r
- /* Destroy temporary data structure */\r
- free(tmp_path);\r
-\r
- return rc;\r
-}\r
-\r
-/**@brief Release extent and all data blocks covered by the extent.\r
- * @param inode_ref I-node to release extent and block from\r
- * @param extent Extent to release\r
- * @return Error code */\r
-static int ext4_extent_release(struct ext4_inode_ref *inode_ref,\r
- struct ext4_extent *extent)\r
-{\r
- /* Compute number of the first physical block to release */\r
- uint64_t start = ext4_extent_get_start(extent);\r
- uint16_t block_count = ext4_extent_get_block_count(extent);\r
-\r
- return ext4_balloc_free_blocks(inode_ref, start, block_count);\r
-}\r
-\r
-/** Recursively release the whole branch of the extent tree.\r
- * For each entry of the node release the subbranch and finally release\r
- * the node. In the leaf node all extents will be released.\r
- * @param inode_ref I-node where the branch is released\r
- * @param index Index in the non-leaf node to be released\r
- * with the whole subtree\r
- * @return Error code */\r
-static int ext4_extent_release_branch(struct ext4_inode_ref *inode_ref,\r
- struct ext4_extent_index *index)\r
-{\r
- uint32_t fblock = ext4_extent_index_get_leaf(index);\r
- uint32_t i;\r
- struct ext4_block block;\r
- int rc = ext4_block_get(inode_ref->fs->bdev, &block, fblock);\r
- if (rc != EOK)\r
- return rc;\r
-\r
- struct ext4_extent_header *header = (void *)block.data;\r
-\r
- if (ext4_extent_header_get_depth(header)) {\r
- /* The node is non-leaf, do recursion */\r
- struct ext4_extent_index *idx = EXT4_EXTENT_FIRST_INDEX(header);\r
-\r
- /* Release all subbranches */\r
- for (i = 0; i < ext4_extent_header_get_entries_count(header);\r
- ++i, ++idx) {\r
- rc = ext4_extent_release_branch(inode_ref, idx);\r
- if (rc != EOK)\r
- return rc;\r
- }\r
- } else {\r
- /* Leaf node reached */\r
- struct ext4_extent *ext = EXT4_EXTENT_FIRST(header);\r
-\r
- /* Release all extents and stop recursion */\r
- for (i = 0; i < ext4_extent_header_get_entries_count(header);\r
- ++i, ++ext) {\r
- rc = ext4_extent_release(inode_ref, ext);\r
- if (rc != EOK)\r
- return rc;\r
- }\r
- }\r
-\r
- /* Release data block where the node was stored */\r
-\r
- rc = ext4_block_set(inode_ref->fs->bdev, &block);\r
- if (rc != EOK)\r
- return rc;\r
-\r
- ext4_balloc_free_block(inode_ref, fblock);\r
-\r
- return EOK;\r
-}\r
-\r
-\r
-int ext4_extent_release_blocks_from(struct ext4_inode_ref *inode_ref,\r
- uint32_t iblock_from)\r
-{\r
- /* Find the first extent to modify */\r
- struct ext4_extent_path *path;\r
- uint16_t i;\r
- int rc = ext4_extent_find_extent(inode_ref, iblock_from, &path);\r
- if (rc != EOK)\r
- return rc;\r
-\r
- /* Jump to last item of the path (extent) */\r
- struct ext4_extent_path *path_ptr = path;\r
- while (path_ptr->depth != 0)\r
- path_ptr++;\r
-\r
- ext4_assert(path_ptr->extent != NULL);\r
-\r
- /* First extent maybe released partially */\r
- uint32_t first_iblock =\r
- ext4_extent_get_first_block(path_ptr->extent);\r
- uint32_t first_fblock =\r
- ext4_extent_get_start(path_ptr->extent) + iblock_from - first_iblock;\r
-\r
- uint16_t block_count = ext4_extent_get_block_count(path_ptr->extent);\r
-\r
- uint16_t delete_count = block_count -\r
- (ext4_extent_get_start(path_ptr->extent) - first_fblock);\r
-\r
- /* Release all blocks */\r
- rc = ext4_balloc_free_blocks(inode_ref, first_fblock, delete_count);\r
- if (rc != EOK)\r
- goto cleanup;\r
-\r
- /* Correct counter */\r
- block_count -= delete_count;\r
- ext4_extent_set_block_count(path_ptr->extent, block_count);\r
-\r
- /* Initialize the following loop */\r
- uint16_t entries =\r
- ext4_extent_header_get_entries_count(path_ptr->header);\r
- struct ext4_extent *tmp_ext = path_ptr->extent + 1;\r
- struct ext4_extent *stop_ext = EXT4_EXTENT_FIRST(path_ptr->header) + entries;\r
-\r
- /* If first extent empty, release it */\r
- if (block_count == 0)\r
- entries--;\r
-\r
- /* Release all successors of the first extent in the same node */\r
- while (tmp_ext < stop_ext) {\r
- first_fblock = ext4_extent_get_start(tmp_ext);\r
- delete_count = ext4_extent_get_block_count(tmp_ext);\r
-\r
- rc = ext4_balloc_free_blocks(inode_ref, first_fblock, delete_count);\r
- if (rc != EOK)\r
- goto cleanup;\r
-\r
- entries--;\r
- tmp_ext++;\r
- }\r
-\r
- ext4_extent_header_set_entries_count(path_ptr->header, entries);\r
- path_ptr->block.dirty = true;\r
-\r
- /* If leaf node is empty, parent entry must be modified */\r
- bool remove_parent_record = false;\r
-\r
- /* Don't release root block (including inode data) !!! */\r
- if ((path_ptr != path) && (entries == 0)) {\r
- rc = ext4_balloc_free_block(inode_ref, path_ptr->block.lb_id);\r
- if (rc != EOK)\r
- goto cleanup;\r
-\r
- remove_parent_record = true;\r
- }\r
-\r
- /* Jump to the parent */\r
- --path_ptr;\r
-\r
- /* Release all successors in all tree levels */\r
- while (path_ptr >= path) {\r
- entries = ext4_extent_header_get_entries_count(path_ptr->header);\r
- struct ext4_extent_index *index = path_ptr->index + 1;\r
- struct ext4_extent_index *stop =\r
- EXT4_EXTENT_FIRST_INDEX(path_ptr->header) + entries;\r
-\r
- /* Correct entries count because of changes in the previous iteration */\r
- if (remove_parent_record)\r
- entries--;\r
-\r
- /* Iterate over all entries and release the whole subtrees */\r
- while (index < stop) {\r
- rc = ext4_extent_release_branch(inode_ref, index);\r
- if (rc != EOK)\r
- goto cleanup;\r
-\r
- ++index;\r
- --entries;\r
- }\r
-\r
- ext4_extent_header_set_entries_count(path_ptr->header, entries);\r
- path_ptr->block.dirty = true;\r
-\r
- /* Free the node if it is empty */\r
- if ((entries == 0) && (path_ptr != path)) {\r
- rc = ext4_balloc_free_block(inode_ref, path_ptr->block.lb_id);\r
- if (rc != EOK)\r
- goto cleanup;\r
-\r
- /* Mark parent to be checked */\r
- remove_parent_record = true;\r
- } else\r
- remove_parent_record = false;\r
-\r
- --path_ptr;\r
- }\r
-\r
-cleanup:\r
- /*\r
- * Put loaded blocks\r
- * starting from 1: 0 is a block with inode data\r
- */\r
- for (i = 1; i <= path->depth; ++i) {\r
- if (path[i].block.lb_id)\r
- ext4_block_set(inode_ref->fs->bdev, &path[i].block);\r
- }\r
-\r
- /* Destroy temporary data structure */\r
- free(path);\r
-\r
- return rc;\r
-}\r
-\r
-/**@brief Append new extent to the i-node and do some splitting if necessary.\r
- * @param inode_ref I-node to append extent to\r
- * @param path Path in the extent tree for possible splitting\r
- * @param last_path_item Input/output parameter for pointer to the last\r
- * valid item in the extent tree path\r
- * @param iblock Logical index of block to append extent for\r
- * @return Error code */\r
-static int ext4_extent_append_extent(struct ext4_inode_ref *inode_ref,\r
- struct ext4_extent_path *path, uint32_t iblock)\r
-{\r
- struct ext4_extent_path *path_ptr = path + path->depth;\r
-\r
- uint32_t block_size =\r
- ext4_sb_get_block_size(&inode_ref->fs->sb);\r
-\r
- /* Start splitting */\r
- while (path_ptr > path) {\r
- uint16_t entries =\r
- ext4_extent_header_get_entries_count(path_ptr->header);\r
- uint16_t limit =\r
- ext4_extent_header_get_max_entries_count(path_ptr->header);\r
-\r
- if (entries == limit) {\r
- /* Full node - allocate block for new one */\r
- uint32_t fblock;\r
- int rc = ext4_balloc_alloc_block(inode_ref, &fblock);\r
- if (rc != EOK)\r
- return rc;\r
-\r
- struct ext4_block block;\r
- rc = ext4_block_get(inode_ref->fs->bdev, &block, fblock);\r
- if (rc != EOK) {\r
- ext4_balloc_free_block(inode_ref, fblock);\r
- return rc;\r
- }\r
-\r
- /* Put back not modified old block */\r
- ext4_block_set(inode_ref->fs->bdev, &path_ptr->block);\r
-\r
- /* Initialize newly allocated block and remember it */\r
- memset(block.data, 0, block_size);\r
- path_ptr->block = block;\r
-\r
- /* Update pointers in extent path structure */\r
- path_ptr->header = (void *)block.data;\r
- if (path_ptr->depth) {\r
- path_ptr->index = EXT4_EXTENT_FIRST_INDEX(path_ptr->header);\r
- ext4_extent_index_set_first_block(path_ptr->index, iblock);\r
- ext4_extent_index_set_leaf(path_ptr->index,\r
- (path_ptr + 1)->block.lb_id);\r
- limit = (block_size - sizeof(struct ext4_extent_header)) /\r
- sizeof(struct ext4_extent_index);\r
- } else {\r
- path_ptr->extent = EXT4_EXTENT_FIRST(path_ptr->header);\r
- ext4_extent_set_first_block(path_ptr->extent, iblock);\r
- limit = (block_size - sizeof(struct ext4_extent_header)) /\r
- sizeof(struct ext4_extent);\r
- }\r
-\r
- /* Initialize on-disk structure (header) */\r
- ext4_extent_header_set_entries_count(path_ptr->header, 1);\r
- ext4_extent_header_set_max_entries_count(path_ptr->header, limit);\r
- ext4_extent_header_set_magic(path_ptr->header, EXT4_EXTENT_MAGIC);\r
- ext4_extent_header_set_depth(path_ptr->header, path_ptr->depth);\r
- ext4_extent_header_set_generation(path_ptr->header, 0);\r
-\r
- path_ptr->block.dirty = true;\r
-\r
- /* Jump to the preceeding item */\r
- path_ptr--;\r
- } else {\r
- /* Node with free space */\r
- if (path_ptr->depth) {\r
- path_ptr->index = EXT4_EXTENT_FIRST_INDEX(path_ptr->header) + entries;\r
- ext4_extent_index_set_first_block(path_ptr->index, iblock);\r
- ext4_extent_index_set_leaf(path_ptr->index,\r
- (path_ptr + 1)->block.lb_id);\r
- } else {\r
- path_ptr->extent = EXT4_EXTENT_FIRST(path_ptr->header) + entries;\r
- ext4_extent_set_first_block(path_ptr->extent, iblock);\r
- }\r
-\r
- ext4_extent_header_set_entries_count(path_ptr->header, entries + 1);\r
- path_ptr->block.dirty = true;\r
-\r
- /* No more splitting needed */\r
- return EOK;\r
- }\r
- }\r
-\r
- ext4_assert(path_ptr == path);\r
-\r
- /* Should be the root split too? */\r
-\r
- uint16_t entries = ext4_extent_header_get_entries_count(path->header);\r
- uint16_t limit = ext4_extent_header_get_max_entries_count(path->header);\r
-\r
- if (entries == limit) {\r
- uint32_t new_fblock;\r
- int rc = ext4_balloc_alloc_block(inode_ref, &new_fblock);\r
- if (rc != EOK)\r
- return rc;\r
-\r
- struct ext4_block block;\r
- rc = ext4_block_get(inode_ref->fs->bdev, &block, new_fblock);\r
- if (rc != EOK)\r
- return rc;\r
-\r
- /* Initialize newly allocated block */\r
- memset(block.data, 0, block_size);\r
-\r
- /* Move data from root to the new block */\r
- memcpy(block.data, inode_ref->inode->blocks,\r
- EXT4_INODE_BLOCKS * sizeof(uint32_t));\r
-\r
- /* Data block is initialized */\r
-\r
- struct ext4_block *root_block = &path->block;\r
- uint16_t root_depth = path->depth;\r
- struct ext4_extent_header *root_header = path->header;\r
-\r
- /* Make space for tree growing */\r
- struct ext4_extent_path *new_root = path;\r
- struct ext4_extent_path *old_root = path + 1;\r
-\r
- size_t nbytes = sizeof(struct ext4_extent_path) * (path->depth + 1);\r
- memmove(old_root, new_root, nbytes);\r
- memset(new_root, 0, sizeof(struct ext4_extent_path));\r
-\r
- /* Update old root structure */\r
- old_root->block = block;\r
- old_root->header = (struct ext4_extent_header *)block.data;\r
-\r
- /* Add new entry and update limit for entries */\r
- if (old_root->depth) {\r
- limit = (block_size - sizeof(struct ext4_extent_header)) /\r
- sizeof(struct ext4_extent_index);\r
- old_root->index = EXT4_EXTENT_FIRST_INDEX(old_root->header) + entries;\r
- ext4_extent_index_set_first_block(old_root->index, iblock);\r
- ext4_extent_index_set_leaf(old_root->index,\r
- (old_root + 1)->block.lb_id);\r
- old_root->extent = NULL;\r
- } else {\r
- limit = (block_size - sizeof(struct ext4_extent_header)) /\r
- sizeof(struct ext4_extent);\r
- old_root->extent = EXT4_EXTENT_FIRST(old_root->header) + entries;\r
- ext4_extent_set_first_block(old_root->extent, iblock);\r
- old_root->index = NULL;\r
- }\r
-\r
- ext4_extent_header_set_entries_count(old_root->header, entries + 1);\r
- ext4_extent_header_set_max_entries_count(old_root->header, limit);\r
-\r
- old_root->block.dirty = true;\r
-\r
- /* Re-initialize new root metadata */\r
- new_root->depth = root_depth + 1;\r
- new_root->block = *root_block;\r
- new_root->header = root_header;\r
- new_root->extent = NULL;\r
- new_root->index = EXT4_EXTENT_FIRST_INDEX(new_root->header);\r
-\r
- ext4_extent_header_set_depth(new_root->header, new_root->depth);\r
-\r
- /* Create new entry in root */\r
- ext4_extent_header_set_entries_count(new_root->header, 1);\r
- ext4_extent_index_set_first_block(new_root->index, 0);\r
- ext4_extent_index_set_leaf(new_root->index, new_fblock);\r
-\r
- new_root->block.dirty = true;\r
- } else {\r
- if (path->depth) {\r
- path->index = EXT4_EXTENT_FIRST_INDEX(path->header) + entries;\r
- ext4_extent_index_set_first_block(path->index, iblock);\r
- ext4_extent_index_set_leaf(path->index, (path + 1)->block.lb_id);\r
- } else {\r
- path->extent = EXT4_EXTENT_FIRST(path->header) + entries;\r
- ext4_extent_set_first_block(path->extent, iblock);\r
- }\r
-\r
- ext4_extent_header_set_entries_count(path->header, entries + 1);\r
- path->block.dirty = true;\r
- }\r
-\r
- return EOK;\r
-}\r
-\r
-\r
-int ext4_extent_append_block(struct ext4_inode_ref *inode_ref,\r
- uint32_t *iblock, uint32_t *fblock, bool update_size)\r
-{\r
- uint16_t i;\r
- struct ext4_sblock *sb = &inode_ref->fs->sb;\r
- uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);\r
- uint32_t block_size = ext4_sb_get_block_size(sb);\r
-\r
- /* Calculate number of new logical block */\r
- uint32_t new_block_idx = 0;\r
- if (inode_size > 0) {\r
- if ((inode_size % block_size) != 0)\r
- inode_size += block_size - (inode_size % block_size);\r
-\r
- new_block_idx = inode_size / block_size;\r
- }\r
-\r
- /* Load the nearest leaf (with extent) */\r
- struct ext4_extent_path *path;\r
- int rc = ext4_extent_find_extent(inode_ref, new_block_idx, &path);\r
- if (rc != EOK)\r
- return rc;\r
-\r
- /* Jump to last item of the path (extent) */\r
- struct ext4_extent_path *path_ptr = path;\r
- while (path_ptr->depth != 0)\r
- path_ptr++;\r
-\r
- /* Add new extent to the node if not present */\r
- if (path_ptr->extent == NULL)\r
- goto append_extent;\r
-\r
- uint16_t block_count = ext4_extent_get_block_count(path_ptr->extent);\r
- uint16_t block_limit = (1 << 15);\r
-\r
- uint32_t phys_block = 0;\r
- if (block_count < block_limit) {\r
- /* There is space for new block in the extent */\r
- if (block_count == 0) {\r
- /* Existing extent is empty */\r
- rc = ext4_balloc_alloc_block(inode_ref, &phys_block);\r
- if (rc != EOK)\r
- goto finish;\r
-\r
- /* Initialize extent */\r
- ext4_extent_set_first_block(path_ptr->extent, new_block_idx);\r
- ext4_extent_set_start(path_ptr->extent, phys_block);\r
- ext4_extent_set_block_count(path_ptr->extent, 1);\r
-\r
- /* Update i-node */\r
- if (update_size) {\r
- ext4_inode_set_size(inode_ref->inode, inode_size + block_size);\r
- inode_ref->dirty = true;\r
- }\r
-\r
- path_ptr->block.dirty = true;\r
-\r
- goto finish;\r
- } else {\r
- /* Existing extent contains some blocks */\r
- phys_block = ext4_extent_get_start(path_ptr->extent);\r
- phys_block += ext4_extent_get_block_count(path_ptr->extent);\r
-\r
- /* Check if the following block is free for allocation */\r
- bool free;\r
- rc = ext4_balloc_try_alloc_block(inode_ref, phys_block, &free);\r
- if (rc != EOK)\r
- goto finish;\r
-\r
- if (!free) {\r
- /* Target is not free, new block must be appended to new extent */\r
- goto append_extent;\r
- }\r
-\r
- /* Update extent */\r
- ext4_extent_set_block_count(path_ptr->extent, block_count + 1);\r
-\r
- /* Update i-node */\r
- if (update_size) {\r
- ext4_inode_set_size(inode_ref->inode, inode_size + block_size);\r
- inode_ref->dirty = true;\r
- }\r
-\r
- path_ptr->block.dirty = true;\r
-\r
- goto finish;\r
- }\r
- }\r
-\r
-\r
-append_extent:\r
- /* Append new extent to the tree */\r
- phys_block = 0;\r
-\r
- /* Allocate new data block */\r
- rc = ext4_balloc_alloc_block(inode_ref, &phys_block);\r
- if (rc != EOK)\r
- goto finish;\r
-\r
- /* Append extent for new block (includes tree splitting if needed) */\r
- rc = ext4_extent_append_extent(inode_ref, path, new_block_idx);\r
- if (rc != EOK) {\r
- ext4_balloc_free_block(inode_ref, phys_block);\r
- goto finish;\r
- }\r
-\r
- uint32_t tree_depth = ext4_extent_header_get_depth(path->header);\r
- path_ptr = path + tree_depth;\r
-\r
- /* Initialize newly created extent */\r
- ext4_extent_set_block_count(path_ptr->extent, 1);\r
- ext4_extent_set_first_block(path_ptr->extent, new_block_idx);\r
- ext4_extent_set_start(path_ptr->extent, phys_block);\r
-\r
- /* Update i-node */\r
- if (update_size) {\r
- ext4_inode_set_size(inode_ref->inode, inode_size + block_size);\r
- inode_ref->dirty = true;\r
- }\r
-\r
- path_ptr->block.dirty = true;\r
-\r
-finish:\r
- /* Set return values */\r
- *iblock = new_block_idx;\r
- *fblock = phys_block;\r
-\r
- /*\r
- * Put loaded blocks\r
- * starting from 1: 0 is a block with inode data\r
- */\r
- for (i = 1; i <= path->depth; ++i) {\r
- if (path[i].block.lb_id)\r
- ext4_block_set(inode_ref->fs->bdev, &path[i].block);\r
- }\r
-\r
- /* Destroy temporary data structure */\r
- free(path);\r
-\r
- return rc;\r
-}\r
-\r
-/**\r
- * @}\r
- */\r
+/*
+ * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
+ *
+ *
+ * HelenOS:
+ * Copyright (c) 2012 Martin Sucha
+ * Copyright (c) 2012 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 lwext4
+ * @{
+ */
+/**
+ * @file ext4_extent.c
+ * @brief More complex filesystem functions.
+ */
+
+#include "ext4_config.h"
+#include "ext4_extent.h"
+#include "ext4_inode.h"
+#include "ext4_super.h"
+#include "ext4_blockdev.h"
+#include "ext4_balloc.h"
+#include "ext4_fs.h"
+
+#include <string.h>
+#include <stdlib.h>
+
+#if !CONFIG_EXTENT_FULL
+
+/**@brief Binary search in extent index node.
+ * @param header Extent header of index node
+ * @param index Output value - found index will be set here
+ * @param iblock Logical block number to find in index node */
+static void ext4_extent_binsearch_idx(struct ext4_extent_header *header,
+ struct ext4_extent_index **index,
+ uint32_t iblock)
+{
+ struct ext4_extent_index *r;
+ struct ext4_extent_index *l;
+ struct ext4_extent_index *m;
+
+ uint16_t entries_count = ext4_extent_header_get_entries_count(header);
+
+ /* Initialize bounds */
+ l = EXT4_EXTENT_FIRST_INDEX(header) + 1;
+ r = EXT4_EXTENT_FIRST_INDEX(header) + entries_count - 1;
+
+ /* Do binary search */
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ uint32_t first_block = ext4_extent_index_get_first_block(m);
+
+ if (iblock < first_block)
+ r = m - 1;
+ else
+ l = m + 1;
+ }
+
+ /* Set output value */
+ *index = l - 1;
+}
+
+/**@brief Binary search in extent leaf node.
+ * @param header Extent header of leaf node
+ * @param extent Output value - found extent will be set here,
+ * or NULL if node is empty
+ * @param iblock Logical block number to find in leaf node */
+static void ext4_extent_binsearch(struct ext4_extent_header *header,
+ struct ext4_extent **extent, uint32_t iblock)
+{
+ struct ext4_extent *r;
+ struct ext4_extent *l;
+ struct ext4_extent *m;
+
+ uint16_t entries_count = ext4_extent_header_get_entries_count(header);
+
+ if (entries_count == 0) {
+ /* this leaf is empty */
+ *extent = NULL;
+ return;
+ }
+
+ /* Initialize bounds */
+ l = EXT4_EXTENT_FIRST(header) + 1;
+ r = EXT4_EXTENT_FIRST(header) + entries_count - 1;
+
+ /* Do binary search */
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ uint32_t first_block = ext4_extent_get_first_block(m);
+
+ if (iblock < first_block)
+ r = m - 1;
+ else
+ l = m + 1;
+ }
+
+ /* Set output value */
+ *extent = l - 1;
+}
+
+static uint32_t ext4_ext_block_csum(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_header *eh)
+{
+ uint32_t checksum = 0;
+ struct ext4_sblock *sb = &inode_ref->fs->sb;
+
+ if (ext4_sb_has_feature_read_only(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+ uint32_t ino_index = to_le32(inode_ref->index);
+ uint32_t ino_gen =
+ to_le32(ext4_inode_get_generation(inode_ref->inode));
+ /* First calculate crc32 checksum against fs uuid */
+ checksum = ext4_crc32c(~0, sb->uuid, sizeof(sb->uuid));
+ /* Then calculate crc32 checksum against inode number
+ * and inode generation */
+ checksum = ext4_crc32c(checksum, &ino_index,
+ sizeof(ino_index));
+ checksum = ext4_crc32c(checksum, &ino_gen,
+ sizeof(ino_gen));
+ /* Finally calculate crc32 checksum against
+ * the entire extent block up to the checksum field */
+ checksum = ext4_crc32c(checksum, eh,
+ EXT4_EXTENT_TAIL_OFFSET(eh));
+ }
+ return checksum;
+}
+
+/*
+ * BIG FAT NOTES:
+ * Currently we do not verify the checksum of extent
+ * (only the case in ext4_extent.c)
+ */
+
+static void ext4_extent_block_csum_set(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_header *eh)
+{
+ struct ext4_extent_tail *tail;
+
+ tail = find_ext4_extent_tail(eh);
+ tail->et_checksum = to_le32(ext4_ext_block_csum(inode_ref, eh));
+}
+
+/**@brief Get physical block in the extent tree by logical block number.
+ * There is no need to save path in the tree during this algorithm.
+ * @param inode_ref I-node to load block from
+ * @param iblock Logical block number to find
+ * @param fblock Output value for physical block number
+ * @return Error code*/
+static int
+ext4_extent_find_block(struct ext4_inode_ref *inode_ref, uint32_t iblock,
+ ext4_fsblk_t *fblock)
+{
+ int rc;
+ /* Compute bound defined by i-node size */
+ uint64_t inode_size =
+ ext4_inode_get_size(&inode_ref->fs->sb, inode_ref->inode);
+
+ uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
+
+ uint32_t last_idx = (inode_size - 1) / block_size;
+
+ /* Check if requested iblock is not over size of i-node */
+ if (iblock > last_idx) {
+ *fblock = 0;
+ return EOK;
+ }
+
+ struct ext4_block block;
+ block.lb_id = 0;
+
+ /* Walk through extent tree */
+ struct ext4_extent_header *header =
+ ext4_inode_get_extent_header(inode_ref->inode);
+
+ while (ext4_extent_header_get_depth(header) != 0) {
+ /* Search index in node */
+ struct ext4_extent_index *index;
+ ext4_extent_binsearch_idx(header, &index, iblock);
+
+ /* Load child node and set values for the next iteration */
+ uint64_t child = ext4_extent_index_get_leaf(index);
+
+ if (block.lb_id) {
+ rc = ext4_block_set(inode_ref->fs->bdev, &block);
+ if (rc != EOK)
+ return rc;
+ }
+
+ int rc = ext4_block_get(inode_ref->fs->bdev, &block, child);
+ if (rc != EOK)
+ return rc;
+
+ header = (struct ext4_extent_header *)block.data;
+ }
+
+ /* Search extent in the leaf block */
+ struct ext4_extent *extent = NULL;
+ ext4_extent_binsearch(header, &extent, iblock);
+
+ /* Prevent empty leaf */
+ if (extent == NULL) {
+ *fblock = 0;
+ } else {
+ /* Compute requested physical block address */
+ ext4_fsblk_t phys_block;
+ uint32_t first = ext4_extent_get_first_block(extent);
+ phys_block = ext4_extent_get_start(extent) + iblock - first;
+
+ *fblock = phys_block;
+ }
+
+ /* Cleanup */
+ if (block.lb_id) {
+ rc = ext4_block_set(inode_ref->fs->bdev, &block);
+ if (rc != EOK)
+ return rc;
+ }
+
+ return EOK;
+}
+
+/**@brief Find extent for specified iblock.
+ * This function is used for finding block in the extent tree with
+ * saving the path through the tree for possible future modifications.
+ * @param inode_ref I-node to read extent tree from
+ * @param iblock Iblock to find extent for
+ * @param ret_path Output value for loaded path from extent tree
+ * @return Error code */
+static int ext4_extent_find_extent(struct ext4_inode_ref *inode_ref,
+ uint32_t iblock,
+ struct ext4_extent_path **ret_path)
+{
+ struct ext4_extent_header *eh =
+ ext4_inode_get_extent_header(inode_ref->inode);
+
+ uint16_t depth = ext4_extent_header_get_depth(eh);
+ uint16_t i;
+ struct ext4_extent_path *tmp_path;
+
+ /* Added 2 for possible tree growing */
+ tmp_path = malloc(sizeof(struct ext4_extent_path) * (depth + 2));
+ if (tmp_path == NULL)
+ return ENOMEM;
+
+ /* Initialize structure for algorithm start */
+ tmp_path[0].block = inode_ref->block;
+ tmp_path[0].header = eh;
+
+ /* Walk through the extent tree */
+ uint16_t pos = 0;
+ int rc;
+ while (ext4_extent_header_get_depth(eh) != 0) {
+ /* Search index in index node by iblock */
+ ext4_extent_binsearch_idx(tmp_path[pos].header,
+ &tmp_path[pos].index, iblock);
+
+ tmp_path[pos].depth = depth;
+ tmp_path[pos].extent = NULL;
+
+ ext4_assert(tmp_path[pos].index != 0);
+
+ /* Load information for the next iteration */
+ uint64_t fblock =
+ ext4_extent_index_get_leaf(tmp_path[pos].index);
+
+ struct ext4_block block;
+ rc = ext4_block_get(inode_ref->fs->bdev, &block, fblock);
+ if (rc != EOK)
+ goto cleanup;
+
+ pos++;
+
+ eh = (struct ext4_extent_header *)block.data;
+ tmp_path[pos].block = block;
+ tmp_path[pos].header = eh;
+ }
+
+ tmp_path[pos].depth = 0;
+ tmp_path[pos].extent = NULL;
+ tmp_path[pos].index = NULL;
+
+ /* Find extent in the leaf node */
+ ext4_extent_binsearch(tmp_path[pos].header, &tmp_path[pos].extent,
+ iblock);
+ *ret_path = tmp_path;
+
+ return EOK;
+
+cleanup:
+ /*
+ * Put loaded blocks
+ * From 1: 0 is a block with inode data
+ */
+ for (i = 1; i < tmp_path->depth; ++i) {
+ if (tmp_path[i].block.lb_id) {
+ int r = ext4_block_set(inode_ref->fs->bdev,
+ &tmp_path[i].block);
+ if (r != EOK)
+ rc = r;
+ }
+ }
+
+ /* Destroy temporary data structure */
+ free(tmp_path);
+
+ return rc;
+}
+
+/**@brief Release extent and all data blocks covered by the extent.
+ * @param inode_ref I-node to release extent and block from
+ * @param extent Extent to release
+ * @return Error code */
+static int ext4_extent_release(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent *extent)
+{
+ /* Compute number of the first physical block to release */
+ uint64_t start = ext4_extent_get_start(extent);
+ uint16_t block_count = ext4_extent_get_block_count(extent);
+
+ return ext4_balloc_free_blocks(inode_ref, start, block_count);
+}
+
+/** Recursively release the whole branch of the extent tree.
+ * For each entry of the node release the subbranch and finally release
+ * the node. In the leaf node all extents will be released.
+ * @param inode_ref I-node where the branch is released
+ * @param index Index in the non-leaf node to be released
+ * with the whole subtree
+ * @return Error code */
+static int ext4_extent_release_branch(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_index *index)
+{
+ ext4_fsblk_t fblock = ext4_extent_index_get_leaf(index);
+ uint32_t i;
+ struct ext4_block block;
+ int rc = ext4_block_get(inode_ref->fs->bdev, &block, fblock);
+ if (rc != EOK)
+ return rc;
+
+ struct ext4_extent_header *header = (void *)block.data;
+
+ if (ext4_extent_header_get_depth(header)) {
+ /* The node is non-leaf, do recursion */
+ struct ext4_extent_index *idx = EXT4_EXTENT_FIRST_INDEX(header);
+
+ /* Release all subbranches */
+ for (i = 0; i < ext4_extent_header_get_entries_count(header);
+ ++i, ++idx) {
+ rc = ext4_extent_release_branch(inode_ref, idx);
+ if (rc != EOK)
+ return rc;
+ }
+ } else {
+ /* Leaf node reached */
+ struct ext4_extent *ext = EXT4_EXTENT_FIRST(header);
+
+ /* Release all extents and stop recursion */
+ for (i = 0; i < ext4_extent_header_get_entries_count(header);
+ ++i, ++ext) {
+ rc = ext4_extent_release(inode_ref, ext);
+ if (rc != EOK)
+ return rc;
+ }
+ }
+
+ /* Release data block where the node was stored */
+
+ rc = ext4_block_set(inode_ref->fs->bdev, &block);
+ if (rc != EOK)
+ return rc;
+
+ return ext4_balloc_free_block(inode_ref, fblock);
+}
+
+int ext4_extent_remove_space(struct ext4_inode_ref *inode_ref, ext4_lblk_t from,
+ ext4_lblk_t to)
+{
+ if (to != EXT_MAX_BLOCKS)
+ return ENOTSUP;
+
+ /* Find the first extent to modify */
+ struct ext4_extent_path *path;
+ uint16_t i;
+ int rc = ext4_extent_find_extent(inode_ref, from, &path);
+ if (rc != EOK)
+ return rc;
+
+ /* Jump to last item of the path (extent) */
+ struct ext4_extent_path *path_ptr = path;
+ while (path_ptr->depth != 0)
+ path_ptr++;
+
+ ext4_assert(path_ptr->extent != NULL);
+
+ /* First extent maybe released partially */
+ uint32_t first_iblock = ext4_extent_get_first_block(path_ptr->extent);
+ ext4_fsblk_t first_fblock = ext4_extent_get_start(path_ptr->extent) +
+ from - first_iblock;
+
+ uint16_t block_count = ext4_extent_get_block_count(path_ptr->extent);
+
+ uint16_t delete_count =
+ block_count -
+ (ext4_extent_get_start(path_ptr->extent) - first_fblock);
+
+ /* Release all blocks */
+ rc = ext4_balloc_free_blocks(inode_ref, first_fblock, delete_count);
+ if (rc != EOK)
+ goto cleanup;
+
+ /* Correct counter */
+ block_count -= delete_count;
+ ext4_extent_set_block_count(path_ptr->extent, block_count,
+ EXT4_EXT_IS_UNWRITTEN(path_ptr->extent));
+
+ /* Initialize the following loop */
+ uint16_t entries =
+ ext4_extent_header_get_entries_count(path_ptr->header);
+ struct ext4_extent *tmp_ext = path_ptr->extent + 1;
+ struct ext4_extent *stop_ext =
+ EXT4_EXTENT_FIRST(path_ptr->header) + entries;
+
+ /* If first extent empty, release it */
+ if (block_count == 0)
+ entries--;
+
+ /* Release all successors of the first extent in the same node */
+ while (tmp_ext < stop_ext) {
+ first_fblock = ext4_extent_get_start(tmp_ext);
+ delete_count = ext4_extent_get_block_count(tmp_ext);
+
+ rc = ext4_balloc_free_blocks(inode_ref, first_fblock,
+ delete_count);
+ if (rc != EOK)
+ goto cleanup;
+
+ entries--;
+ tmp_ext++;
+ }
+
+ ext4_extent_header_set_entries_count(path_ptr->header, entries);
+ ext4_extent_block_csum_set(inode_ref, path_ptr->header);
+ path_ptr->block.dirty = true;
+
+ /* If leaf node is empty, parent entry must be modified */
+ bool remove_parent_record = false;
+
+ /* Don't release root block (including inode data) !!! */
+ if ((path_ptr != path) && (entries == 0)) {
+ rc = ext4_balloc_free_block(inode_ref, path_ptr->block.lb_id);
+ if (rc != EOK)
+ goto cleanup;
+
+ remove_parent_record = true;
+ }
+
+ /* Jump to the parent */
+ --path_ptr;
+
+ /* Release all successors in all tree levels */
+ while (path_ptr >= path) {
+ entries =
+ ext4_extent_header_get_entries_count(path_ptr->header);
+ struct ext4_extent_index *index = path_ptr->index + 1;
+ struct ext4_extent_index *stop =
+ EXT4_EXTENT_FIRST_INDEX(path_ptr->header) + entries;
+
+ /* Correct entries count because of changes in the previous
+ * iteration */
+ if (remove_parent_record)
+ entries--;
+
+ /* Iterate over all entries and release the whole subtrees */
+ while (index < stop) {
+ rc = ext4_extent_release_branch(inode_ref, index);
+ if (rc != EOK)
+ goto cleanup;
+
+ ++index;
+ --entries;
+ }
+
+ ext4_extent_header_set_entries_count(path_ptr->header, entries);
+ ext4_extent_block_csum_set(inode_ref, path_ptr->header);
+ path_ptr->block.dirty = true;
+
+ /* Free the node if it is empty */
+ if ((entries == 0) && (path_ptr != path)) {
+ rc = ext4_balloc_free_block(inode_ref,
+ path_ptr->block.lb_id);
+ if (rc != EOK)
+ goto cleanup;
+
+ /* Mark parent to be checked */
+ remove_parent_record = true;
+ } else
+ remove_parent_record = false;
+
+ --path_ptr;
+ }
+
+ if (!entries)
+ ext4_extent_header_set_depth(path->header, 0);
+
+cleanup:
+ /*
+ * Put loaded blocks
+ * starting from 1: 0 is a block with inode data
+ */
+ for (i = 1; i <= path->depth; ++i) {
+ if (path[i].block.lb_id) {
+ int r =
+ ext4_block_set(inode_ref->fs->bdev, &path[i].block);
+ if (r != EOK)
+ rc = r;
+ }
+ }
+
+ /* Destroy temporary data structure */
+ free(path);
+
+ return rc;
+}
+
+/**@brief Append new extent to the i-node and do some splitting if necessary.
+ * @param inode_ref I-node to append extent to
+ * @param path Path in the extent tree for possible splitting
+ * @param last_path_item Input/output parameter for pointer to the last
+ * valid item in the extent tree path
+ * @param iblock Logical index of block to append extent for
+ * @return Error code */
+static int ext4_extent_append_extent(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_path *path,
+ uint32_t iblock)
+{
+ struct ext4_extent_path *path_ptr = path + path->depth;
+
+ uint32_t block_size = ext4_sb_get_block_size(&inode_ref->fs->sb);
+
+ /* Start splitting */
+ while (path_ptr > path) {
+ uint16_t entries =
+ ext4_extent_header_get_entries_count(path_ptr->header);
+ uint16_t limit =
+ ext4_extent_header_get_max_entries_count(path_ptr->header);
+
+ if (entries == limit) {
+ /* Full node - allocate block for new one */
+ ext4_fsblk_t goal, fblock;
+ int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
+ if (rc != EOK)
+ return rc;
+
+ rc = ext4_balloc_alloc_block(inode_ref, goal, &fblock);
+ if (rc != EOK)
+ return rc;
+
+ struct ext4_block block;
+ rc =
+ ext4_block_get(inode_ref->fs->bdev, &block, fblock);
+ if (rc != EOK) {
+ ext4_balloc_free_block(inode_ref, fblock);
+ return rc;
+ }
+
+ /* Put back not modified old block */
+ rc = ext4_block_set(inode_ref->fs->bdev,
+ &path_ptr->block);
+ if (rc != EOK) {
+ ext4_balloc_free_block(inode_ref, fblock);
+ return rc;
+ }
+
+ /* Initialize newly allocated block and remember it */
+ memset(block.data, 0, block_size);
+ path_ptr->block = block;
+
+ /* Update pointers in extent path structure */
+ path_ptr->header = (void *)block.data;
+ if (path_ptr->depth) {
+ path_ptr->index =
+ EXT4_EXTENT_FIRST_INDEX(path_ptr->header);
+ ext4_extent_index_set_first_block(
+ path_ptr->index, iblock);
+ ext4_extent_index_set_leaf(
+ path_ptr->index,
+ (path_ptr + 1)->block.lb_id);
+ limit = (block_size -
+ sizeof(struct ext4_extent_header)) /
+ sizeof(struct ext4_extent_index);
+ } else {
+ path_ptr->extent =
+ EXT4_EXTENT_FIRST(path_ptr->header);
+ ext4_extent_set_first_block(path_ptr->extent,
+ iblock);
+ limit = (block_size -
+ sizeof(struct ext4_extent_header)) /
+ sizeof(struct ext4_extent);
+ }
+
+ /* Initialize on-disk structure (header) */
+ ext4_extent_header_set_entries_count(path_ptr->header,
+ 1);
+ ext4_extent_header_set_max_entries_count(
+ path_ptr->header, limit);
+ ext4_extent_header_set_magic(path_ptr->header,
+ EXT4_EXTENT_MAGIC);
+ ext4_extent_header_set_depth(path_ptr->header,
+ path_ptr->depth);
+ ext4_extent_header_set_generation(path_ptr->header, 0);
+
+ ext4_extent_block_csum_set(inode_ref, path_ptr->header);
+ path_ptr->block.dirty = true;
+
+ /* Jump to the preceding item */
+ path_ptr--;
+ } else {
+ /* Node with free space */
+ if (path_ptr->depth) {
+ path_ptr->index =
+ EXT4_EXTENT_FIRST_INDEX(path_ptr->header) +
+ entries;
+ ext4_extent_index_set_first_block(
+ path_ptr->index, iblock);
+ ext4_extent_index_set_leaf(
+ path_ptr->index,
+ (path_ptr + 1)->block.lb_id);
+ } else {
+ path_ptr->extent =
+ EXT4_EXTENT_FIRST(path_ptr->header) +
+ entries;
+ ext4_extent_set_first_block(path_ptr->extent,
+ iblock);
+ }
+
+ ext4_extent_header_set_entries_count(path_ptr->header,
+ entries + 1);
+ ext4_extent_block_csum_set(inode_ref, path_ptr->header);
+ path_ptr->block.dirty = true;
+
+ /* No more splitting needed */
+ return EOK;
+ }
+ }
+
+ ext4_assert(path_ptr == path);
+
+ /* Should be the root split too? */
+
+ uint16_t entries = ext4_extent_header_get_entries_count(path->header);
+ uint16_t limit = ext4_extent_header_get_max_entries_count(path->header);
+
+ if (entries == limit) {
+ ext4_fsblk_t goal, new_fblock;
+ int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
+ if (rc != EOK)
+ return rc;
+
+ rc = ext4_balloc_alloc_block(inode_ref, goal, &new_fblock);
+ if (rc != EOK)
+ return rc;
+
+ struct ext4_block block;
+ rc = ext4_block_get(inode_ref->fs->bdev, &block, new_fblock);
+ if (rc != EOK)
+ return rc;
+
+ /* Initialize newly allocated block */
+ memset(block.data, 0, block_size);
+
+ /* Move data from root to the new block */
+ memcpy(block.data, inode_ref->inode->blocks,
+ EXT4_INODE_BLOCKS * sizeof(uint32_t));
+
+ /* Data block is initialized */
+
+ struct ext4_block *root_block = &path->block;
+ uint16_t root_depth = path->depth;
+ struct ext4_extent_header *root_header = path->header;
+
+ /* Make space for tree growing */
+ struct ext4_extent_path *new_root = path;
+ struct ext4_extent_path *old_root = path + 1;
+
+ size_t nbytes =
+ sizeof(struct ext4_extent_path) * (path->depth + 1);
+ memmove(old_root, new_root, nbytes);
+ memset(new_root, 0, sizeof(struct ext4_extent_path));
+
+ /* Update old root structure */
+ old_root->block = block;
+ old_root->header = (struct ext4_extent_header *)block.data;
+
+ /* Add new entry and update limit for entries */
+ if (old_root->depth) {
+ limit =
+ (block_size - sizeof(struct ext4_extent_header)) /
+ sizeof(struct ext4_extent_index);
+ old_root->index =
+ EXT4_EXTENT_FIRST_INDEX(old_root->header) + entries;
+ ext4_extent_index_set_first_block(old_root->index,
+ iblock);
+ ext4_extent_index_set_leaf(old_root->index,
+ (old_root + 1)->block.lb_id);
+ old_root->extent = NULL;
+ } else {
+ limit =
+ (block_size - sizeof(struct ext4_extent_header)) /
+ sizeof(struct ext4_extent);
+ old_root->extent =
+ EXT4_EXTENT_FIRST(old_root->header) + entries;
+ ext4_extent_set_first_block(old_root->extent, iblock);
+ old_root->index = NULL;
+ }
+
+ ext4_extent_header_set_entries_count(old_root->header,
+ entries + 1);
+ ext4_extent_header_set_max_entries_count(old_root->header,
+ limit);
+
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(old_root->block));
+ old_root->block.dirty = true;
+
+ /* Re-initialize new root metadata */
+ new_root->depth = root_depth + 1;
+ new_root->block = *root_block;
+ new_root->header = root_header;
+ new_root->extent = NULL;
+ new_root->index = EXT4_EXTENT_FIRST_INDEX(new_root->header);
+
+ ext4_extent_header_set_depth(new_root->header, new_root->depth);
+
+ /* Create new entry in root */
+ ext4_extent_header_set_entries_count(new_root->header, 1);
+ ext4_extent_index_set_first_block(new_root->index, 0);
+ ext4_extent_index_set_leaf(new_root->index, new_fblock);
+
+ /* Since new_root belongs to on-disk inode,
+ * we don't do checksum here */
+ new_root->block.dirty = true;
+ } else {
+ if (path->depth) {
+ path->index =
+ EXT4_EXTENT_FIRST_INDEX(path->header) + entries;
+ ext4_extent_index_set_first_block(path->index, iblock);
+ ext4_extent_index_set_leaf(path->index,
+ (path + 1)->block.lb_id);
+ } else {
+ path->extent =
+ EXT4_EXTENT_FIRST(path->header) + entries;
+ ext4_extent_set_first_block(path->extent, iblock);
+ }
+
+ ext4_extent_header_set_entries_count(path->header, entries + 1);
+ /* Since new_root belongs to on-disk inode,
+ * we don't do checksum here */
+ path->block.dirty = true;
+ }
+
+ return EOK;
+}
+
+/**@brief Append data block to the i-node.
+ * This function allocates data block, tries to append it
+ * to some existing extent or creates new extents.
+ * It includes possible extent tree modifications (splitting).
+ * @param inode_ref I-node to append block to
+ * @param iblock Output logical number of newly allocated block
+ * @param fblock Output physical block address of newly allocated block
+ *
+ * @return Error code*/
+static int
+ext4_extent_append_block(struct ext4_inode_ref *inode_ref, uint32_t *iblock,
+ ext4_fsblk_t *fblock, bool update_size)
+{
+ uint16_t i;
+ ext4_fsblk_t goal;
+ struct ext4_sblock *sb = &inode_ref->fs->sb;
+ uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
+ uint32_t block_size = ext4_sb_get_block_size(sb);
+
+ /* Calculate number of new logical block */
+ uint32_t new_block_idx = 0;
+ if (inode_size > 0) {
+ if ((inode_size % block_size) != 0)
+ inode_size += block_size - (inode_size % block_size);
+
+ new_block_idx = inode_size / block_size;
+ }
+
+ /* Load the nearest leaf (with extent) */
+ struct ext4_extent_path *path;
+ int rc = ext4_extent_find_extent(inode_ref, new_block_idx, &path);
+ if (rc != EOK)
+ return rc;
+
+ /* Jump to last item of the path (extent) */
+ struct ext4_extent_path *path_ptr = path;
+ while (path_ptr->depth != 0)
+ path_ptr++;
+
+ /* Add new extent to the node if not present */
+ if (path_ptr->extent == NULL)
+ goto append_extent;
+
+ uint16_t block_count = ext4_extent_get_block_count(path_ptr->extent);
+ uint16_t block_limit = (1 << 15);
+
+ ext4_fsblk_t phys_block = 0;
+ if (block_count < block_limit) {
+ /* There is space for new block in the extent */
+ if (block_count == 0) {
+ int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
+ if (rc != EOK)
+ goto finish;
+
+ /* Existing extent is empty */
+ rc = ext4_balloc_alloc_block(inode_ref, goal, &phys_block);
+ if (rc != EOK)
+ goto finish;
+
+ /* Initialize extent */
+ ext4_extent_set_first_block(path_ptr->extent,
+ new_block_idx);
+ ext4_extent_set_start(path_ptr->extent, phys_block);
+ ext4_extent_set_block_count(path_ptr->extent, 1,
+ false);
+
+ /* Update i-node */
+ if (update_size) {
+ ext4_inode_set_size(inode_ref->inode,
+ inode_size + block_size);
+ inode_ref->dirty = true;
+ }
+
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(path_ptr->block));
+ path_ptr->block.dirty = true;
+
+ goto finish;
+ } else {
+ ext4_fsblk_t goal;
+ int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
+ if (rc != EOK)
+ goto finish;
+
+ /* Existing extent contains some blocks */
+ phys_block = ext4_extent_get_start(path_ptr->extent);
+ phys_block +=
+ ext4_extent_get_block_count(path_ptr->extent);
+
+ /* Check if the following block is free for allocation
+ */
+ bool free;
+ rc = ext4_balloc_try_alloc_block(inode_ref, phys_block,
+ &free);
+ if (rc != EOK)
+ goto finish;
+
+ if (!free) {
+ /* Target is not free, new block must be
+ * appended to new extent
+ */
+ goto append_extent;
+ }
+
+ /* Update extent */
+ ext4_extent_set_block_count(path_ptr->extent,
+ block_count + 1,
+ false);
+
+ /* Update i-node */
+ if (update_size) {
+ ext4_inode_set_size(inode_ref->inode,
+ inode_size + block_size);
+ inode_ref->dirty = true;
+ }
+
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(path_ptr->block));
+ path_ptr->block.dirty = true;
+
+ goto finish;
+ }
+ }
+
+append_extent:
+ /* Append new extent to the tree */
+ phys_block = 0;
+
+ rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
+ if (rc != EOK)
+ goto finish;
+
+ /* Allocate new data block */
+ rc = ext4_balloc_alloc_block(inode_ref, goal, &phys_block);
+ if (rc != EOK)
+ goto finish;
+
+ /* Append extent for new block (includes tree splitting if needed) */
+ rc = ext4_extent_append_extent(inode_ref, path, new_block_idx);
+ if (rc != EOK) {
+ ext4_balloc_free_block(inode_ref, phys_block);
+ goto finish;
+ }
+
+ uint32_t tree_depth = ext4_extent_header_get_depth(path->header);
+ path_ptr = path + tree_depth;
+
+ /* Initialize newly created extent */
+ ext4_extent_set_block_count(path_ptr->extent, 1, false);
+ ext4_extent_set_first_block(path_ptr->extent, new_block_idx);
+ ext4_extent_set_start(path_ptr->extent, phys_block);
+
+ /* Update i-node */
+ if (update_size) {
+ ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
+ inode_ref->dirty = true;
+ }
+
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(path_ptr->block));
+ path_ptr->block.dirty = true;
+
+finish:
+ /* Set return values */
+ *iblock = new_block_idx;
+ *fblock = phys_block;
+
+ /*
+ * Put loaded blocks
+ * starting from 1: 0 is a block with inode data
+ */
+ for (i = 1; i <= path->depth; ++i) {
+ if (path[i].block.lb_id) {
+ int r =
+ ext4_block_set(inode_ref->fs->bdev, &path[i].block);
+ if (r != EOK)
+ rc = r;
+ }
+ }
+
+ /* Destroy temporary data structure */
+ free(path);
+
+ return rc;
+}
+
+int ext4_extent_get_blocks(struct ext4_inode_ref *inode_ref, ext4_fsblk_t iblock,
+ ext4_lblk_t max_blocks, ext4_fsblk_t *result, bool create,
+ ext4_lblk_t *blocks_count)
+{
+ uint32_t iblk = iblock;
+ ext4_fsblk_t fblk = 0;
+ int r;
+
+ if (blocks_count)
+ return ENOTSUP;
+ if (max_blocks != 1)
+ return ENOTSUP;
+
+ if (!create)
+ r = ext4_extent_find_block(inode_ref, iblk, &fblk);
+ else
+ r = ext4_extent_append_block(inode_ref, &iblk, &fblk, false);
+
+ *result = fblk;
+ return r;
+}
+
+#endif
+/**
+ * @}
+ */
projects / lwext4.git / blobdiff