+/*
+ * 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"
+#include "internal.h"
+
+#define MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r->fs_info) - \
+ sizeof(struct btrfs_item) * 2) / \
+ size) - 1))
+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;
+ int is_hole = 0;
+ struct btrfs_file_extent_item *item;
+ struct btrfs_key file_key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+
+ if (offset == 0)
+ is_hole = 1;
+ /* For NO_HOLES, we don't insert hole file extent */
+ if (btrfs_fs_incompat(root->fs_info, NO_HOLES) && is_hole)
+ return 0;
+
+ /* For hole, its disk_bytenr and disk_num_bytes must be 0 */
+ if (is_hole)
+ disk_num_bytes = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ file_key.objectid = objectid;
+ file_key.offset = pos;
+ file_key.type = 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, const 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;
+ key.type = 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;
+}
+
+static 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;
+ file_key.type = 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 (found_key.type != BTRFS_EXTENT_CSUM_KEY)
+ goto fail;
+
+ csum_offset = (bytenr - found_key.offset) /
+ root->fs_info->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_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 sectorsize = root->fs_info->sectorsize;
+ u32 nritems;
+ u32 ins_size;
+ u16 csum_size =
+ btrfs_super_csum_size(root->fs_info->super_copy);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ 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(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) / 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(root, path, diff);
+ BUG_ON(ret);
+ goto csum;
+ }
+
+insert:
+ btrfs_release_path(path);
+ csum_offset = 0;
+ if (found_next) {
+ u64 tmp = min(alloc_end, next_offset);
+ tmp -= file_key.offset;
+ tmp /= 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(data, csum_result, len);
+ btrfs_csum_final(csum_result, (u8 *)&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_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_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->fs_info->sectorsize;
+ int ret;
+
+ leaf = path->nodes[0];
+ csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
+ csum_end *= root->fs_info->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(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(root, path, new_size, 0);
+ BUG_ON(ret);
+
+ key->offset = end_byte;
+ ret = btrfs_set_item_key_safe(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->fs_info->sectorsize;
+
+ root = root->fs_info->csum_root;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ 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(root, path, &key, bytenr, len);
+ BUG_ON(ret);
+ }
+ btrfs_release_path(path);
+ }
+out:
+ btrfs_free_path(path);
+ return 0;
+}
projects / platform / upstream / btrfs-progs.git / blobdiff