779 lines
18 KiB
C
779 lines
18 KiB
C
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/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#define _XOPEN_SOURCE 600
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#define __USE_XOPEN2K
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include "kerncompat.h"
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#include "extent_io.h"
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#include "list.h"
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u64 cache_max = 1024 * 1024 * 32;
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void extent_io_tree_init(struct extent_io_tree *tree)
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{
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cache_tree_init(&tree->state);
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cache_tree_init(&tree->cache);
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INIT_LIST_HEAD(&tree->lru);
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tree->cache_size = 0;
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}
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static struct extent_state *alloc_extent_state(void)
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{
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struct extent_state *state;
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state = malloc(sizeof(*state));
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if (!state)
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return NULL;
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state->refs = 1;
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state->state = 0;
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state->private = 0;
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return state;
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}
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static void free_extent_state(struct extent_state *state)
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{
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state->refs--;
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BUG_ON(state->refs < 0);
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if (state->refs == 0)
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free(state);
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}
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void extent_io_tree_cleanup(struct extent_io_tree *tree)
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{
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struct extent_state *es;
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struct extent_buffer *eb;
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struct cache_extent *cache;
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while(!list_empty(&tree->lru)) {
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eb = list_entry(tree->lru.next, struct extent_buffer, lru);
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if (eb->refs != 1) {
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fprintf(stderr, "extent buffer leak: "
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"start %llu len %u\n",
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(unsigned long long)eb->start, eb->len);
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eb->refs = 1;
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}
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free_extent_buffer(eb);
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}
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while (1) {
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cache = find_first_cache_extent(&tree->state, 0);
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if (!cache)
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break;
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es = container_of(cache, struct extent_state, cache_node);
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remove_cache_extent(&tree->state, &es->cache_node);
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free_extent_state(es);
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}
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}
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static inline void update_extent_state(struct extent_state *state)
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{
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state->cache_node.start = state->start;
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state->cache_node.size = state->end + 1 - state->start;
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}
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/*
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* Utility function to look for merge candidates inside a given range.
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* Any extents with matching state are merged together into a single
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* extent in the tree. Extents with EXTENT_IO in their state field are
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* not merged
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*/
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static int merge_state(struct extent_io_tree *tree,
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struct extent_state *state)
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{
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struct extent_state *other;
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struct cache_extent *other_node;
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if (state->state & EXTENT_IOBITS)
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return 0;
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other_node = prev_cache_extent(&state->cache_node);
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if (other_node) {
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other = container_of(other_node, struct extent_state,
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cache_node);
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if (other->end == state->start - 1 &&
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other->state == state->state) {
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state->start = other->start;
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update_extent_state(state);
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remove_cache_extent(&tree->state, &other->cache_node);
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free_extent_state(other);
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}
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}
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other_node = next_cache_extent(&state->cache_node);
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if (other_node) {
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other = container_of(other_node, struct extent_state,
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cache_node);
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if (other->start == state->end + 1 &&
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other->state == state->state) {
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other->start = state->start;
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update_extent_state(other);
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remove_cache_extent(&tree->state, &state->cache_node);
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free_extent_state(state);
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}
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}
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return 0;
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}
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/*
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* insert an extent_state struct into the tree. 'bits' are set on the
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* struct before it is inserted.
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*/
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static int insert_state(struct extent_io_tree *tree,
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struct extent_state *state, u64 start, u64 end,
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int bits)
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{
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int ret;
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BUG_ON(end < start);
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state->state |= bits;
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state->start = start;
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state->end = end;
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update_extent_state(state);
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ret = insert_existing_cache_extent(&tree->state, &state->cache_node);
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BUG_ON(ret);
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merge_state(tree, state);
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return 0;
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}
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/*
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* split a given extent state struct in two, inserting the preallocated
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* struct 'prealloc' as the newly created second half. 'split' indicates an
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* offset inside 'orig' where it should be split.
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*/
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static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
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struct extent_state *prealloc, u64 split)
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{
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int ret;
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prealloc->start = orig->start;
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prealloc->end = split - 1;
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prealloc->state = orig->state;
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update_extent_state(prealloc);
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orig->start = split;
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update_extent_state(orig);
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ret = insert_existing_cache_extent(&tree->state,
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&prealloc->cache_node);
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BUG_ON(ret);
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return 0;
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}
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/*
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* clear some bits on a range in the tree.
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*/
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static int clear_state_bit(struct extent_io_tree *tree,
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struct extent_state *state, int bits)
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{
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int ret = state->state & bits;
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state->state &= ~bits;
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if (state->state == 0) {
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remove_cache_extent(&tree->state, &state->cache_node);
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free_extent_state(state);
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} else {
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merge_state(tree, state);
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}
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return ret;
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}
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/*
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* set some bits on a range in the tree.
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*/
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int clear_extent_bits(struct extent_io_tree *tree, u64 start,
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u64 end, int bits, gfp_t mask)
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{
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struct extent_state *state;
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struct extent_state *prealloc = NULL;
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struct cache_extent *node;
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u64 last_end;
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int err;
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int set = 0;
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again:
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prealloc = alloc_extent_state();
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if (!prealloc)
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return -ENOMEM;
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/*
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* this search will find the extents that end after
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* our range starts
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*/
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node = find_first_cache_extent(&tree->state, start);
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if (!node)
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goto out;
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state = container_of(node, struct extent_state, cache_node);
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if (state->start > end)
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goto out;
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last_end = state->end;
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/*
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* | ---- desired range ---- |
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* | state | or
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* | ------------- state -------------- |
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*
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* We need to split the extent we found, and may flip
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* bits on second half.
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*
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* If the extent we found extends past our range, we
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* just split and search again. It'll get split again
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* the next time though.
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*
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* If the extent we found is inside our range, we clear
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* the desired bit on it.
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*/
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if (state->start < start) {
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err = split_state(tree, state, prealloc, start);
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BUG_ON(err == -EEXIST);
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prealloc = NULL;
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if (err)
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goto out;
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if (state->end <= end) {
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set |= clear_state_bit(tree, state, bits);
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if (last_end == (u64)-1)
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goto out;
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start = last_end + 1;
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} else {
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start = state->start;
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}
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goto search_again;
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}
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/*
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* | ---- desired range ---- |
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* | state |
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* We need to split the extent, and clear the bit
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* on the first half
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*/
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if (state->start <= end && state->end > end) {
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err = split_state(tree, state, prealloc, end + 1);
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BUG_ON(err == -EEXIST);
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set |= clear_state_bit(tree, prealloc, bits);
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prealloc = NULL;
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goto out;
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}
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start = state->end + 1;
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set |= clear_state_bit(tree, state, bits);
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if (last_end == (u64)-1)
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goto out;
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start = last_end + 1;
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goto search_again;
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out:
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if (prealloc)
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free_extent_state(prealloc);
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return set;
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search_again:
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if (start > end)
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goto out;
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goto again;
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}
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/*
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* set some bits on a range in the tree.
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*/
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int set_extent_bits(struct extent_io_tree *tree, u64 start,
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u64 end, int bits, gfp_t mask)
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{
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struct extent_state *state;
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struct extent_state *prealloc = NULL;
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struct cache_extent *node;
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int err = 0;
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u64 last_start;
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u64 last_end;
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again:
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prealloc = alloc_extent_state();
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if (!prealloc)
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return -ENOMEM;
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/*
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* this search will find the extents that end after
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* our range starts
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*/
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node = find_first_cache_extent(&tree->state, start);
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if (!node) {
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err = insert_state(tree, prealloc, start, end, bits);
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BUG_ON(err == -EEXIST);
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prealloc = NULL;
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goto out;
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}
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state = container_of(node, struct extent_state, cache_node);
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last_start = state->start;
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last_end = state->end;
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/*
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* | ---- desired range ---- |
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* | state |
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*
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* Just lock what we found and keep going
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*/
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if (state->start == start && state->end <= end) {
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state->state |= bits;
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merge_state(tree, state);
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if (last_end == (u64)-1)
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goto out;
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start = last_end + 1;
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goto search_again;
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}
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/*
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* | ---- desired range ---- |
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* | state |
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* or
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* | ------------- state -------------- |
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*
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* We need to split the extent we found, and may flip bits on
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* second half.
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*
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* If the extent we found extends past our
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* range, we just split and search again. It'll get split
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* again the next time though.
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*
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* If the extent we found is inside our range, we set the
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* desired bit on it.
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*/
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if (state->start < start) {
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err = split_state(tree, state, prealloc, start);
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BUG_ON(err == -EEXIST);
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prealloc = NULL;
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if (err)
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goto out;
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if (state->end <= end) {
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state->state |= bits;
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start = state->end + 1;
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merge_state(tree, state);
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if (last_end == (u64)-1)
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goto out;
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start = last_end + 1;
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} else {
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start = state->start;
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}
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goto search_again;
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}
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/*
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* | ---- desired range ---- |
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* | state | or | state |
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*
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* There's a hole, we need to insert something in it and
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* ignore the extent we found.
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*/
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if (state->start > start) {
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u64 this_end;
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if (end < last_start)
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this_end = end;
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else
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this_end = last_start -1;
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err = insert_state(tree, prealloc, start, this_end,
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bits);
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BUG_ON(err == -EEXIST);
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prealloc = NULL;
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if (err)
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goto out;
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start = this_end + 1;
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goto search_again;
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}
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/*
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* | ---- desired range ---- |
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* | ---------- state ---------- |
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* We need to split the extent, and set the bit
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* on the first half
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*/
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err = split_state(tree, state, prealloc, end + 1);
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BUG_ON(err == -EEXIST);
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state->state |= bits;
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merge_state(tree, prealloc);
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prealloc = NULL;
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out:
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if (prealloc)
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free_extent_state(prealloc);
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return err;
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search_again:
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if (start > end)
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goto out;
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goto again;
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}
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int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
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gfp_t mask)
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{
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return set_extent_bits(tree, start, end, EXTENT_DIRTY, mask);
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}
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int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
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gfp_t mask)
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{
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return clear_extent_bits(tree, start, end, EXTENT_DIRTY, mask);
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}
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int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
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u64 *start_ret, u64 *end_ret, int bits)
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{
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struct cache_extent *node;
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struct extent_state *state;
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int ret = 1;
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/*
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* this search will find all the extents that end after
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* our range starts.
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*/
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node = find_first_cache_extent(&tree->state, start);
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if (!node)
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goto out;
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while(1) {
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state = container_of(node, struct extent_state, cache_node);
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if (state->end >= start && (state->state & bits)) {
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*start_ret = state->start;
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*end_ret = state->end;
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ret = 0;
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break;
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}
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node = next_cache_extent(node);
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if (!node)
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break;
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}
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out:
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return ret;
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}
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int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
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int bits, int filled)
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{
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struct extent_state *state = NULL;
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struct cache_extent *node;
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int bitset = 0;
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node = find_first_cache_extent(&tree->state, start);
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while (node && start <= end) {
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state = container_of(node, struct extent_state, cache_node);
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if (filled && state->start > start) {
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bitset = 0;
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break;
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}
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if (state->start > end)
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break;
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if (state->state & bits) {
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bitset = 1;
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if (!filled)
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break;
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} else if (filled) {
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bitset = 0;
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break;
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}
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start = state->end + 1;
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if (start > end)
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break;
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node = next_cache_extent(node);
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if (!node) {
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if (filled)
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bitset = 0;
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break;
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}
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}
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return bitset;
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}
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int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
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{
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struct cache_extent *node;
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struct extent_state *state;
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int ret = 0;
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node = find_first_cache_extent(&tree->state, start);
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if (!node) {
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ret = -ENOENT;
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goto out;
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}
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state = container_of(node, struct extent_state, cache_node);
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if (state->start != start) {
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ret = -ENOENT;
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goto out;
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}
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state->private = private;
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out:
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return ret;
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}
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int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
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{
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struct cache_extent *node;
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struct extent_state *state;
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int ret = 0;
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node = find_first_cache_extent(&tree->state, start);
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if (!node) {
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ret = -ENOENT;
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goto out;
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}
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state = container_of(node, struct extent_state, cache_node);
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if (state->start != start) {
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ret = -ENOENT;
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goto out;
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}
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*private = state->private;
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out:
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return ret;
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}
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static int free_some_buffers(struct extent_io_tree *tree)
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{
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u32 nrscan = 0;
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struct extent_buffer *eb;
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struct list_head *node, *next;
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if (tree->cache_size < cache_max)
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return 0;
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list_for_each_safe(node, next, &tree->lru) {
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eb = list_entry(node, struct extent_buffer, lru);
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if (eb->refs == 1) {
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free_extent_buffer(eb);
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if (tree->cache_size < cache_max)
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break;
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} else {
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list_move_tail(&eb->lru, &tree->lru);
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}
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if (nrscan++ > 64)
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break;
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}
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return 0;
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}
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static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
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u64 bytenr, u32 blocksize)
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{
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struct extent_buffer *eb;
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int ret;
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|
|
eb = malloc(sizeof(struct extent_buffer) + blocksize);
|
|
if (!eb) {
|
|
BUG();
|
|
return NULL;
|
|
}
|
|
memset(eb, 0, sizeof(struct extent_buffer) + blocksize);
|
|
|
|
eb->start = bytenr;
|
|
eb->len = blocksize;
|
|
eb->refs = 2;
|
|
eb->flags = 0;
|
|
eb->tree = tree;
|
|
eb->fd = -1;
|
|
eb->dev_bytenr = (u64)-1;
|
|
eb->cache_node.start = bytenr;
|
|
eb->cache_node.size = blocksize;
|
|
|
|
free_some_buffers(tree);
|
|
ret = insert_existing_cache_extent(&tree->cache, &eb->cache_node);
|
|
if (ret) {
|
|
free(eb);
|
|
return NULL;
|
|
}
|
|
list_add_tail(&eb->lru, &tree->lru);
|
|
tree->cache_size += blocksize;
|
|
return eb;
|
|
}
|
|
|
|
void free_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
if (!eb)
|
|
return;
|
|
|
|
eb->refs--;
|
|
BUG_ON(eb->refs < 0);
|
|
if (eb->refs == 0) {
|
|
struct extent_io_tree *tree = eb->tree;
|
|
BUG_ON(eb->flags & EXTENT_DIRTY);
|
|
list_del_init(&eb->lru);
|
|
remove_cache_extent(&tree->cache, &eb->cache_node);
|
|
BUG_ON(tree->cache_size < eb->len);
|
|
tree->cache_size -= eb->len;
|
|
free(eb);
|
|
}
|
|
}
|
|
|
|
struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
|
|
u64 bytenr, u32 blocksize)
|
|
{
|
|
struct extent_buffer *eb = NULL;
|
|
struct cache_extent *cache;
|
|
|
|
cache = find_cache_extent(&tree->cache, bytenr, blocksize);
|
|
if (cache && cache->start == bytenr && cache->size == blocksize) {
|
|
eb = container_of(cache, struct extent_buffer, cache_node);
|
|
list_move_tail(&eb->lru, &tree->lru);
|
|
eb->refs++;
|
|
}
|
|
return eb;
|
|
}
|
|
|
|
struct extent_buffer *find_first_extent_buffer(struct extent_io_tree *tree,
|
|
u64 start)
|
|
{
|
|
struct extent_buffer *eb = NULL;
|
|
struct cache_extent *cache;
|
|
|
|
cache = find_first_cache_extent(&tree->cache, start);
|
|
if (cache) {
|
|
eb = container_of(cache, struct extent_buffer, cache_node);
|
|
list_move_tail(&eb->lru, &tree->lru);
|
|
eb->refs++;
|
|
}
|
|
return eb;
|
|
}
|
|
|
|
struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
|
|
u64 bytenr, u32 blocksize)
|
|
{
|
|
struct extent_buffer *eb;
|
|
struct cache_extent *cache;
|
|
|
|
cache = find_cache_extent(&tree->cache, bytenr, blocksize);
|
|
if (cache && cache->start == bytenr && cache->size == blocksize) {
|
|
eb = container_of(cache, struct extent_buffer, cache_node);
|
|
list_move_tail(&eb->lru, &tree->lru);
|
|
eb->refs++;
|
|
} else {
|
|
if (cache) {
|
|
eb = container_of(cache, struct extent_buffer,
|
|
cache_node);
|
|
BUG_ON(eb->refs != 1);
|
|
free_extent_buffer(eb);
|
|
}
|
|
eb = __alloc_extent_buffer(tree, bytenr, blocksize);
|
|
}
|
|
return eb;
|
|
}
|
|
|
|
int read_extent_from_disk(struct extent_buffer *eb)
|
|
{
|
|
int ret;
|
|
ret = pread(eb->fd, eb->data, eb->len, eb->dev_bytenr);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret != eb->len) {
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
ret = 0;
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
int write_extent_to_disk(struct extent_buffer *eb)
|
|
{
|
|
int ret;
|
|
ret = pwrite(eb->fd, eb->data, eb->len, eb->dev_bytenr);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret != eb->len) {
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
ret = 0;
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
int set_extent_buffer_uptodate(struct extent_buffer *eb)
|
|
{
|
|
eb->flags |= EXTENT_UPTODATE;
|
|
return 0;
|
|
}
|
|
|
|
int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
|
|
struct extent_buffer *eb)
|
|
{
|
|
eb->flags &= ~EXTENT_UPTODATE;
|
|
return 0;
|
|
}
|
|
|
|
int extent_buffer_uptodate(struct extent_buffer *eb)
|
|
{
|
|
if (eb->flags & EXTENT_UPTODATE)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
int set_extent_buffer_dirty(struct extent_buffer *eb)
|
|
{
|
|
struct extent_io_tree *tree = eb->tree;
|
|
if (!(eb->flags & EXTENT_DIRTY)) {
|
|
eb->flags |= EXTENT_DIRTY;
|
|
set_extent_dirty(tree, eb->start, eb->start + eb->len - 1, 0);
|
|
extent_buffer_get(eb);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int clear_extent_buffer_dirty(struct extent_buffer *eb)
|
|
{
|
|
struct extent_io_tree *tree = eb->tree;
|
|
if (eb->flags & EXTENT_DIRTY) {
|
|
eb->flags &= ~EXTENT_DIRTY;
|
|
clear_extent_dirty(tree, eb->start, eb->start + eb->len - 1, 0);
|
|
free_extent_buffer(eb);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
return memcmp(eb->data + start, ptrv, len);
|
|
}
|
|
|
|
void read_extent_buffer(struct extent_buffer *eb, void *dst,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
memcpy(dst, eb->data + start, len);
|
|
}
|
|
|
|
void write_extent_buffer(struct extent_buffer *eb, const void *src,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
memcpy(eb->data + start, src, len);
|
|
}
|
|
|
|
void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
|
|
unsigned long dst_offset, unsigned long src_offset,
|
|
unsigned long len)
|
|
{
|
|
memcpy(dst->data + dst_offset, src->data + src_offset, len);
|
|
}
|
|
|
|
void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
|
|
unsigned long src_offset, unsigned long len)
|
|
{
|
|
memcpy(dst->data + dst_offset, dst->data + src_offset, len);
|
|
}
|
|
|
|
void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
|
|
unsigned long src_offset, unsigned long len)
|
|
{
|
|
memmove(dst->data + dst_offset, dst->data + src_offset, len);
|
|
}
|
|
|
|
void memset_extent_buffer(struct extent_buffer *eb, char c,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
memset(eb->data + start, c, len);
|
|
}
|