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171 lines
6.1 KiB
171 lines
6.1 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2007 Oracle. All rights reserved. |
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*/ |
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#include <asm/unaligned.h> |
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#include "ctree.h" |
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static bool check_setget_bounds(const struct extent_buffer *eb, |
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const void *ptr, unsigned off, int size) |
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{ |
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const unsigned long member_offset = (unsigned long)ptr + off; |
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if (member_offset > eb->len) { |
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btrfs_warn(eb->fs_info, |
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"bad eb member start: ptr 0x%lx start %llu member offset %lu size %d", |
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(unsigned long)ptr, eb->start, member_offset, size); |
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return false; |
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} |
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if (member_offset + size > eb->len) { |
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btrfs_warn(eb->fs_info, |
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"bad eb member end: ptr 0x%lx start %llu member offset %lu size %d", |
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(unsigned long)ptr, eb->start, member_offset, size); |
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return false; |
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} |
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return true; |
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} |
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/* |
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* Macro templates that define helpers to read/write extent buffer data of a |
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* given size, that are also used via ctree.h for access to item members by |
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* specialized helpers. |
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* |
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* Generic helpers: |
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* - btrfs_set_8 (for 8/16/32/64) |
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* - btrfs_get_8 (for 8/16/32/64) |
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* |
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* Generic helpers with a token (cached address of the most recently accessed |
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* page): |
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* - btrfs_set_token_8 (for 8/16/32/64) |
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* - btrfs_get_token_8 (for 8/16/32/64) |
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* |
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* The set/get functions handle data spanning two pages transparently, in case |
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* metadata block size is larger than page. Every pointer to metadata items is |
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* an offset into the extent buffer page array, cast to a specific type. This |
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* gives us all the type checking. |
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* |
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* The extent buffer pages stored in the array pages do not form a contiguous |
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* phyusical range, but the API functions assume the linear offset to the range |
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* from 0 to metadata node size. |
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*/ |
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#define DEFINE_BTRFS_SETGET_BITS(bits) \ |
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u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \ |
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const void *ptr, unsigned long off) \ |
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{ \ |
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const unsigned long member_offset = (unsigned long)ptr + off; \ |
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const unsigned long idx = get_eb_page_index(member_offset); \ |
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const unsigned long oip = get_eb_offset_in_page(token->eb, \ |
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member_offset); \ |
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const int size = sizeof(u##bits); \ |
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u8 lebytes[sizeof(u##bits)]; \ |
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const int part = PAGE_SIZE - oip; \ |
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\ |
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ASSERT(token); \ |
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ASSERT(token->kaddr); \ |
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ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \ |
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if (token->offset <= member_offset && \ |
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member_offset + size <= token->offset + PAGE_SIZE) { \ |
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return get_unaligned_le##bits(token->kaddr + oip); \ |
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} \ |
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token->kaddr = page_address(token->eb->pages[idx]); \ |
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token->offset = idx << PAGE_SHIFT; \ |
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if (oip + size <= PAGE_SIZE) \ |
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return get_unaligned_le##bits(token->kaddr + oip); \ |
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\ |
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memcpy(lebytes, token->kaddr + oip, part); \ |
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token->kaddr = page_address(token->eb->pages[idx + 1]); \ |
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token->offset = (idx + 1) << PAGE_SHIFT; \ |
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memcpy(lebytes + part, token->kaddr, size - part); \ |
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return get_unaligned_le##bits(lebytes); \ |
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} \ |
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u##bits btrfs_get_##bits(const struct extent_buffer *eb, \ |
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const void *ptr, unsigned long off) \ |
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{ \ |
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const unsigned long member_offset = (unsigned long)ptr + off; \ |
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const unsigned long oip = get_eb_offset_in_page(eb, member_offset); \ |
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const unsigned long idx = get_eb_page_index(member_offset); \ |
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char *kaddr = page_address(eb->pages[idx]); \ |
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const int size = sizeof(u##bits); \ |
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const int part = PAGE_SIZE - oip; \ |
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u8 lebytes[sizeof(u##bits)]; \ |
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\ |
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ASSERT(check_setget_bounds(eb, ptr, off, size)); \ |
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if (oip + size <= PAGE_SIZE) \ |
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return get_unaligned_le##bits(kaddr + oip); \ |
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\ |
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memcpy(lebytes, kaddr + oip, part); \ |
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kaddr = page_address(eb->pages[idx + 1]); \ |
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memcpy(lebytes + part, kaddr, size - part); \ |
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return get_unaligned_le##bits(lebytes); \ |
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} \ |
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void btrfs_set_token_##bits(struct btrfs_map_token *token, \ |
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const void *ptr, unsigned long off, \ |
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u##bits val) \ |
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{ \ |
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const unsigned long member_offset = (unsigned long)ptr + off; \ |
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const unsigned long idx = get_eb_page_index(member_offset); \ |
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const unsigned long oip = get_eb_offset_in_page(token->eb, \ |
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member_offset); \ |
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const int size = sizeof(u##bits); \ |
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u8 lebytes[sizeof(u##bits)]; \ |
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const int part = PAGE_SIZE - oip; \ |
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\ |
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ASSERT(token); \ |
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ASSERT(token->kaddr); \ |
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ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \ |
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if (token->offset <= member_offset && \ |
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member_offset + size <= token->offset + PAGE_SIZE) { \ |
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put_unaligned_le##bits(val, token->kaddr + oip); \ |
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return; \ |
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} \ |
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token->kaddr = page_address(token->eb->pages[idx]); \ |
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token->offset = idx << PAGE_SHIFT; \ |
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if (oip + size <= PAGE_SIZE) { \ |
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put_unaligned_le##bits(val, token->kaddr + oip); \ |
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return; \ |
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} \ |
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put_unaligned_le##bits(val, lebytes); \ |
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memcpy(token->kaddr + oip, lebytes, part); \ |
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token->kaddr = page_address(token->eb->pages[idx + 1]); \ |
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token->offset = (idx + 1) << PAGE_SHIFT; \ |
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memcpy(token->kaddr, lebytes + part, size - part); \ |
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} \ |
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void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr, \ |
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unsigned long off, u##bits val) \ |
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{ \ |
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const unsigned long member_offset = (unsigned long)ptr + off; \ |
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const unsigned long oip = get_eb_offset_in_page(eb, member_offset); \ |
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const unsigned long idx = get_eb_page_index(member_offset); \ |
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char *kaddr = page_address(eb->pages[idx]); \ |
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const int size = sizeof(u##bits); \ |
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const int part = PAGE_SIZE - oip; \ |
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u8 lebytes[sizeof(u##bits)]; \ |
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\ |
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ASSERT(check_setget_bounds(eb, ptr, off, size)); \ |
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if (oip + size <= PAGE_SIZE) { \ |
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put_unaligned_le##bits(val, kaddr + oip); \ |
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return; \ |
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} \ |
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\ |
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put_unaligned_le##bits(val, lebytes); \ |
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memcpy(kaddr + oip, lebytes, part); \ |
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kaddr = page_address(eb->pages[idx + 1]); \ |
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memcpy(kaddr, lebytes + part, size - part); \ |
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} |
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DEFINE_BTRFS_SETGET_BITS(8) |
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DEFINE_BTRFS_SETGET_BITS(16) |
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DEFINE_BTRFS_SETGET_BITS(32) |
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DEFINE_BTRFS_SETGET_BITS(64) |
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void btrfs_node_key(const struct extent_buffer *eb, |
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struct btrfs_disk_key *disk_key, int nr) |
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{ |
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unsigned long ptr = btrfs_node_key_ptr_offset(nr); |
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read_eb_member(eb, (struct btrfs_key_ptr *)ptr, |
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struct btrfs_key_ptr, key, disk_key); |
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}
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