| /* |
| * Copyright (C) 2007 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include "kerncompat.h" |
| #include "radix-tree.h" |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "print-tree.h" |
| #include "crc32c.h" |
| |
| #define MAX_CSUM_ITEMS(r,size) ((((BTRFS_LEAF_DATA_SIZE(r) - \ |
| sizeof(struct btrfs_item) * 2) / \ |
| size) - 1)) |
| int btrfs_create_file(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 dirid, u64 *objectid) |
| { |
| return 0; |
| } |
| |
| int btrfs_insert_file_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 objectid, u64 pos, u64 offset, |
| u64 disk_num_bytes, u64 num_bytes) |
| { |
| int ret = 0; |
| struct btrfs_file_extent_item *item; |
| struct btrfs_key file_key; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| |
| path = btrfs_alloc_path(); |
| BUG_ON(!path); |
| file_key.objectid = objectid; |
| file_key.offset = pos; |
| btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY); |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &file_key, |
| sizeof(*item)); |
| if (ret < 0) |
| goto out; |
| BUG_ON(ret); |
| leaf = path->nodes[0]; |
| item = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_disk_bytenr(leaf, item, offset); |
| btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes); |
| btrfs_set_file_extent_offset(leaf, item, 0); |
| btrfs_set_file_extent_num_bytes(leaf, item, num_bytes); |
| btrfs_set_file_extent_ram_bytes(leaf, item, num_bytes); |
| btrfs_set_file_extent_generation(leaf, item, trans->transid); |
| btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); |
| btrfs_set_file_extent_compression(leaf, item, 0); |
| btrfs_set_file_extent_encryption(leaf, item, 0); |
| btrfs_set_file_extent_other_encoding(leaf, item, 0); |
| btrfs_mark_buffer_dirty(leaf); |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_insert_inline_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 objectid, |
| u64 offset, char *buffer, size_t size) |
| { |
| struct btrfs_key key; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| unsigned long ptr; |
| struct btrfs_file_extent_item *ei; |
| u32 datasize; |
| int err = 0; |
| int ret; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| key.objectid = objectid; |
| key.offset = offset; |
| btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); |
| |
| datasize = btrfs_file_extent_calc_inline_size(size); |
| ret = btrfs_insert_empty_item(trans, root, path, &key, datasize); |
| if (ret) { |
| err = ret; |
| goto fail; |
| } |
| |
| leaf = path->nodes[0]; |
| ei = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_generation(leaf, ei, trans->transid); |
| btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); |
| btrfs_set_file_extent_ram_bytes(leaf, ei, size); |
| btrfs_set_file_extent_compression(leaf, ei, 0); |
| btrfs_set_file_extent_encryption(leaf, ei, 0); |
| btrfs_set_file_extent_other_encoding(leaf, ei, 0); |
| |
| ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset; |
| write_extent_buffer(leaf, buffer, ptr, size); |
| btrfs_mark_buffer_dirty(leaf); |
| fail: |
| btrfs_free_path(path); |
| return err; |
| } |
| |
| struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 bytenr, int cow) |
| { |
| int ret; |
| struct btrfs_key file_key; |
| struct btrfs_key found_key; |
| struct btrfs_csum_item *item; |
| struct extent_buffer *leaf; |
| u64 csum_offset = 0; |
| u16 csum_size = |
| btrfs_super_csum_size(&root->fs_info->super_copy); |
| int csums_in_item; |
| |
| file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; |
| file_key.offset = bytenr; |
| btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY); |
| ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow); |
| if (ret < 0) |
| goto fail; |
| leaf = path->nodes[0]; |
| if (ret > 0) { |
| ret = 1; |
| if (path->slots[0] == 0) |
| goto fail; |
| path->slots[0]--; |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY) |
| goto fail; |
| |
| csum_offset = (bytenr - found_key.offset) / root->sectorsize; |
| csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]); |
| csums_in_item /= csum_size; |
| |
| if (csum_offset >= csums_in_item) { |
| ret = -EFBIG; |
| goto fail; |
| } |
| } |
| item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); |
| item = (struct btrfs_csum_item *)((unsigned char *)item + |
| csum_offset * csum_size); |
| return item; |
| fail: |
| if (ret > 0) |
| ret = -ENOENT; |
| return ERR_PTR(ret); |
| } |
| |
| int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, u64 objectid, |
| u64 offset, int mod) |
| { |
| int ret; |
| struct btrfs_key file_key; |
| int ins_len = mod < 0 ? -1 : 0; |
| int cow = mod != 0; |
| |
| file_key.objectid = objectid; |
| file_key.offset = offset; |
| btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY); |
| ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow); |
| return ret; |
| } |
| |
| int btrfs_csum_file_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 alloc_end, |
| u64 bytenr, char *data, size_t len) |
| { |
| int ret = 0; |
| struct btrfs_key file_key; |
| struct btrfs_key found_key; |
| u64 next_offset = (u64)-1; |
| int found_next = 0; |
| struct btrfs_path *path; |
| struct btrfs_csum_item *item; |
| struct extent_buffer *leaf = NULL; |
| u64 csum_offset; |
| u32 csum_result = ~(u32)0; |
| u32 nritems; |
| u32 ins_size; |
| u16 csum_size = |
| btrfs_super_csum_size(&root->fs_info->super_copy); |
| |
| path = btrfs_alloc_path(); |
| BUG_ON(!path); |
| |
| file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; |
| file_key.offset = bytenr; |
| file_key.type = BTRFS_EXTENT_CSUM_KEY; |
| |
| item = btrfs_lookup_csum(trans, root, path, bytenr, 1); |
| if (!IS_ERR(item)) { |
| leaf = path->nodes[0]; |
| ret = 0; |
| goto found; |
| } |
| ret = PTR_ERR(item); |
| if (ret == -EFBIG) { |
| u32 item_size; |
| /* we found one, but it isn't big enough yet */ |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| if ((item_size / csum_size) >= MAX_CSUM_ITEMS(root, csum_size)) { |
| /* already at max size, make a new one */ |
| goto insert; |
| } |
| } else { |
| int slot = path->slots[0] + 1; |
| /* we didn't find a csum item, insert one */ |
| nritems = btrfs_header_nritems(path->nodes[0]); |
| if (path->slots[0] >= nritems - 1) { |
| ret = btrfs_next_leaf(root, path); |
| if (ret == 1) |
| found_next = 1; |
| if (ret != 0) |
| goto insert; |
| slot = 0; |
| } |
| btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot); |
| if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || |
| found_key.type != BTRFS_EXTENT_CSUM_KEY) { |
| found_next = 1; |
| goto insert; |
| } |
| next_offset = found_key.offset; |
| found_next = 1; |
| goto insert; |
| } |
| |
| /* |
| * at this point, we know the tree has an item, but it isn't big |
| * enough yet to put our csum in. Grow it |
| */ |
| btrfs_release_path(root, path); |
| ret = btrfs_search_slot(trans, root, &file_key, path, |
| csum_size, 1); |
| if (ret < 0) |
| goto fail; |
| if (ret == 0) { |
| BUG(); |
| } |
| if (path->slots[0] == 0) { |
| goto insert; |
| } |
| path->slots[0]--; |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| csum_offset = (file_key.offset - found_key.offset) / root->sectorsize; |
| if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || |
| found_key.type != BTRFS_EXTENT_CSUM_KEY || |
| csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) { |
| goto insert; |
| } |
| if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) / |
| csum_size) { |
| u32 diff = (csum_offset + 1) * csum_size; |
| diff = diff - btrfs_item_size_nr(leaf, path->slots[0]); |
| if (diff != csum_size) |
| goto insert; |
| ret = btrfs_extend_item(trans, root, path, diff); |
| BUG_ON(ret); |
| goto csum; |
| } |
| |
| insert: |
| btrfs_release_path(root, path); |
| csum_offset = 0; |
| if (found_next) { |
| u64 tmp = min(alloc_end, next_offset); |
| tmp -= file_key.offset; |
| tmp /= root->sectorsize; |
| tmp = max((u64)1, tmp); |
| tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size)); |
| ins_size = csum_size * tmp; |
| } else { |
| ins_size = csum_size; |
| } |
| ret = btrfs_insert_empty_item(trans, root, path, &file_key, |
| ins_size); |
| if (ret < 0) |
| goto fail; |
| if (ret != 0) { |
| WARN_ON(1); |
| goto fail; |
| } |
| csum: |
| leaf = path->nodes[0]; |
| item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); |
| ret = 0; |
| item = (struct btrfs_csum_item *)((unsigned char *)item + |
| csum_offset * csum_size); |
| found: |
| csum_result = btrfs_csum_data(root, data, csum_result, len); |
| btrfs_csum_final(csum_result, (char *)&csum_result); |
| if (csum_result == 0) { |
| printk("csum result is 0 for block %llu\n", |
| (unsigned long long)bytenr); |
| } |
| |
| write_extent_buffer(leaf, &csum_result, (unsigned long)item, |
| csum_size); |
| btrfs_mark_buffer_dirty(path->nodes[0]); |
| fail: |
| btrfs_release_path(root, path); |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * helper function for csum removal, this expects the |
| * key to describe the csum pointed to by the path, and it expects |
| * the csum to overlap the range [bytenr, len] |
| * |
| * The csum should not be entirely contained in the range and the |
| * range should not be entirely contained in the csum. |
| * |
| * This calls btrfs_truncate_item with the correct args based on the |
| * overlap, and fixes up the key as required. |
| */ |
| static noinline int truncate_one_csum(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_key *key, |
| u64 bytenr, u64 len) |
| { |
| struct extent_buffer *leaf; |
| u16 csum_size = |
| btrfs_super_csum_size(&root->fs_info->super_copy); |
| u64 csum_end; |
| u64 end_byte = bytenr + len; |
| u32 blocksize = root->sectorsize; |
| int ret; |
| |
| leaf = path->nodes[0]; |
| csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size; |
| csum_end *= root->sectorsize; |
| csum_end += key->offset; |
| |
| if (key->offset < bytenr && csum_end <= end_byte) { |
| /* |
| * [ bytenr - len ] |
| * [ ] |
| * [csum ] |
| * A simple truncate off the end of the item |
| */ |
| u32 new_size = (bytenr - key->offset) / blocksize; |
| new_size *= csum_size; |
| ret = btrfs_truncate_item(trans, root, path, new_size, 1); |
| BUG_ON(ret); |
| } else if (key->offset >= bytenr && csum_end > end_byte && |
| end_byte > key->offset) { |
| /* |
| * [ bytenr - len ] |
| * [ ] |
| * [csum ] |
| * we need to truncate from the beginning of the csum |
| */ |
| u32 new_size = (csum_end - end_byte) / blocksize; |
| new_size *= csum_size; |
| |
| ret = btrfs_truncate_item(trans, root, path, new_size, 0); |
| BUG_ON(ret); |
| |
| key->offset = end_byte; |
| ret = btrfs_set_item_key_safe(trans, root, path, key); |
| BUG_ON(ret); |
| } else { |
| BUG(); |
| } |
| return 0; |
| } |
| |
| /* |
| * deletes the csum items from the csum tree for a given |
| * range of bytes. |
| */ |
| int btrfs_del_csums(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 bytenr, u64 len) |
| { |
| struct btrfs_path *path; |
| struct btrfs_key key; |
| u64 end_byte = bytenr + len; |
| u64 csum_end; |
| struct extent_buffer *leaf; |
| int ret; |
| u16 csum_size = |
| btrfs_super_csum_size(&root->fs_info->super_copy); |
| int blocksize = root->sectorsize; |
| |
| root = root->fs_info->csum_root; |
| |
| path = btrfs_alloc_path(); |
| |
| while (1) { |
| key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; |
| key.offset = end_byte - 1; |
| key.type = BTRFS_EXTENT_CSUM_KEY; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret > 0) { |
| if (path->slots[0] == 0) |
| goto out; |
| path->slots[0]--; |
| } |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| |
| if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || |
| key.type != BTRFS_EXTENT_CSUM_KEY) { |
| break; |
| } |
| |
| if (key.offset >= end_byte) |
| break; |
| |
| csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size; |
| csum_end *= blocksize; |
| csum_end += key.offset; |
| |
| /* this csum ends before we start, we're done */ |
| if (csum_end <= bytenr) |
| break; |
| |
| /* delete the entire item, it is inside our range */ |
| if (key.offset >= bytenr && csum_end <= end_byte) { |
| ret = btrfs_del_item(trans, root, path); |
| BUG_ON(ret); |
| } else if (key.offset < bytenr && csum_end > end_byte) { |
| unsigned long offset; |
| unsigned long shift_len; |
| unsigned long item_offset; |
| /* |
| * [ bytenr - len ] |
| * [csum ] |
| * |
| * Our bytes are in the middle of the csum, |
| * we need to split this item and insert a new one. |
| * |
| * But we can't drop the path because the |
| * csum could change, get removed, extended etc. |
| * |
| * The trick here is the max size of a csum item leaves |
| * enough room in the tree block for a single |
| * item header. So, we split the item in place, |
| * adding a new header pointing to the existing |
| * bytes. Then we loop around again and we have |
| * a nicely formed csum item that we can neatly |
| * truncate. |
| */ |
| offset = (bytenr - key.offset) / blocksize; |
| offset *= csum_size; |
| |
| shift_len = (len / blocksize) * csum_size; |
| |
| item_offset = btrfs_item_ptr_offset(leaf, |
| path->slots[0]); |
| |
| memset_extent_buffer(leaf, 0, item_offset + offset, |
| shift_len); |
| key.offset = bytenr; |
| |
| /* |
| * btrfs_split_item returns -EAGAIN when the |
| * item changed size or key |
| */ |
| ret = btrfs_split_item(trans, root, path, &key, offset); |
| BUG_ON(ret && ret != -EAGAIN); |
| |
| key.offset = end_byte - 1; |
| } else { |
| ret = truncate_one_csum(trans, root, path, |
| &key, bytenr, len); |
| BUG_ON(ret); |
| } |
| btrfs_release_path(root, path); |
| } |
| out: |
| btrfs_free_path(path); |
| return 0; |
| } |