blob: c79792671e851e0f66079300c3af85d1864f53d5 [file] [log] [blame]
/*
* 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.
*/
#define _XOPEN_SOURCE 600
#define __USE_XOPEN2K
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "kerncompat.h"
#include "extent_map.h"
#include "list.h"
u64 cache_max = 1024 * 1024 * 32;
void extent_map_tree_init(struct extent_map_tree *tree)
{
cache_tree_init(&tree->state);
cache_tree_init(&tree->cache);
INIT_LIST_HEAD(&tree->lru);
tree->cache_size = 0;
}
static struct extent_state *alloc_extent_state(void)
{
struct extent_state *state;
state = malloc(sizeof(*state));
if (!state)
return NULL;
state->refs = 1;
state->state = 0;
state->private = 0;
return state;
}
static void free_extent_state(struct extent_state *state)
{
state->refs--;
BUG_ON(state->refs < 0);
if (state->refs == 0)
free(state);
}
void extent_map_tree_cleanup(struct extent_map_tree *tree)
{
struct extent_state *es;
struct extent_buffer *eb;
struct cache_extent *cache;
while(!list_empty(&tree->lru)) {
eb = list_entry(tree->lru.next, struct extent_buffer, lru);
if (eb->refs != 1) {
fprintf(stderr, "extent buffer leak: "
"start %Lu len %u\n", eb->start, eb->len);
eb->refs = 1;
}
free_extent_buffer(eb);
}
while (1) {
cache = find_first_cache_extent(&tree->state, 0);
if (!cache)
break;
es = container_of(cache, struct extent_state, cache_node);
remove_cache_extent(&tree->state, &es->cache_node);
free_extent_state(es);
}
}
static inline void update_extent_state(struct extent_state *state)
{
state->cache_node.start = state->start;
state->cache_node.size = state->end + 1 - state->start;
}
/*
* Utility function to look for merge candidates inside a given range.
* Any extents with matching state are merged together into a single
* extent in the tree. Extents with EXTENT_IO in their state field are
* not merged
*/
static int merge_state(struct extent_map_tree *tree,
struct extent_state *state)
{
struct extent_state *other;
struct cache_extent *other_node;
if (state->state & EXTENT_IOBITS)
return 0;
other_node = prev_cache_extent(&state->cache_node);
if (other_node) {
other = container_of(other_node, struct extent_state,
cache_node);
if (other->end == state->start - 1 &&
other->state == state->state) {
state->start = other->start;
update_extent_state(state);
remove_cache_extent(&tree->state, &other->cache_node);
free_extent_state(other);
}
}
other_node = next_cache_extent(&state->cache_node);
if (other_node) {
other = container_of(other_node, struct extent_state,
cache_node);
if (other->start == state->end + 1 &&
other->state == state->state) {
other->start = state->start;
update_extent_state(other);
remove_cache_extent(&tree->state, &state->cache_node);
free_extent_state(state);
}
}
return 0;
}
/*
* insert an extent_state struct into the tree. 'bits' are set on the
* struct before it is inserted.
*/
static int insert_state(struct extent_map_tree *tree,
struct extent_state *state, u64 start, u64 end,
int bits)
{
int ret;
BUG_ON(end < start);
state->state |= bits;
state->start = start;
state->end = end;
update_extent_state(state);
ret = insert_existing_cache_extent(&tree->state, &state->cache_node);
BUG_ON(ret);
merge_state(tree, state);
return 0;
}
/*
* split a given extent state struct in two, inserting the preallocated
* struct 'prealloc' as the newly created second half. 'split' indicates an
* offset inside 'orig' where it should be split.
*/
static int split_state(struct extent_map_tree *tree, struct extent_state *orig,
struct extent_state *prealloc, u64 split)
{
int ret;
prealloc->start = orig->start;
prealloc->end = split - 1;
prealloc->state = orig->state;
update_extent_state(prealloc);
orig->start = split;
update_extent_state(orig);
ret = insert_existing_cache_extent(&tree->state,
&prealloc->cache_node);
BUG_ON(ret);
return 0;
}
/*
* clear some bits on a range in the tree.
*/
static int clear_state_bit(struct extent_map_tree *tree,
struct extent_state *state, int bits)
{
int ret = state->state & bits;
state->state &= ~bits;
if (state->state == 0) {
remove_cache_extent(&tree->state, &state->cache_node);
free_extent_state(state);
} else {
merge_state(tree, state);
}
return ret;
}
/*
* set some bits on a range in the tree.
*/
int clear_extent_bits(struct extent_map_tree *tree, u64 start,
u64 end, int bits, gfp_t mask)
{
struct extent_state *state;
struct extent_state *prealloc = NULL;
struct cache_extent *node;
int err;
int set = 0;
again:
prealloc = alloc_extent_state();
if (!prealloc)
return -ENOMEM;
/*
* this search will find the extents that end after
* our range starts
*/
node = find_first_cache_extent(&tree->state, start);
if (!node)
goto out;
state = container_of(node, struct extent_state, cache_node);
if (state->start > end)
goto out;
/*
* | ---- desired range ---- |
* | state | or
* | ------------- state -------------- |
*
* We need to split the extent we found, and may flip
* bits on second half.
*
* If the extent we found extends past our range, we
* just split and search again. It'll get split again
* the next time though.
*
* If the extent we found is inside our range, we clear
* the desired bit on it.
*/
if (state->start < start) {
err = split_state(tree, state, prealloc, start);
BUG_ON(err == -EEXIST);
prealloc = NULL;
if (err)
goto out;
if (state->end <= end) {
start = state->end + 1;
set |= clear_state_bit(tree, state, bits);
} else {
start = state->start;
}
goto search_again;
}
/*
* | ---- desired range ---- |
* | state |
* We need to split the extent, and clear the bit
* on the first half
*/
if (state->start <= end && state->end > end) {
err = split_state(tree, state, prealloc, end + 1);
BUG_ON(err == -EEXIST);
set |= clear_state_bit(tree, prealloc, bits);
prealloc = NULL;
goto out;
}
start = state->end + 1;
set |= clear_state_bit(tree, state, bits);
goto search_again;
out:
if (prealloc)
free_extent_state(prealloc);
return set;
search_again:
if (start > end)
goto out;
goto again;
}
/*
* set some bits on a range in the tree.
*/
int set_extent_bits(struct extent_map_tree *tree, u64 start,
u64 end, int bits, gfp_t mask)
{
struct extent_state *state;
struct extent_state *prealloc = NULL;
struct cache_extent *node;
int err = 0;
int set;
u64 last_start;
u64 last_end;
again:
prealloc = alloc_extent_state();
if (!prealloc)
return -ENOMEM;
/*
* this search will find the extents that end after
* our range starts
*/
node = find_first_cache_extent(&tree->state, start);
if (!node) {
err = insert_state(tree, prealloc, start, end, bits);
BUG_ON(err == -EEXIST);
prealloc = NULL;
goto out;
}
state = container_of(node, struct extent_state, cache_node);
last_start = state->start;
last_end = state->end;
/*
* | ---- desired range ---- |
* | state |
*
* Just lock what we found and keep going
*/
if (state->start == start && state->end <= end) {
set = state->state & bits;
state->state |= bits;
start = state->end + 1;
merge_state(tree, state);
goto search_again;
}
/*
* | ---- desired range ---- |
* | state |
* or
* | ------------- state -------------- |
*
* We need to split the extent we found, and may flip bits on
* second half.
*
* If the extent we found extends past our
* range, we just split and search again. It'll get split
* again the next time though.
*
* If the extent we found is inside our range, we set the
* desired bit on it.
*/
if (state->start < start) {
set = state->state & bits;
err = split_state(tree, state, prealloc, start);
BUG_ON(err == -EEXIST);
prealloc = NULL;
if (err)
goto out;
if (state->end <= end) {
state->state |= bits;
start = state->end + 1;
merge_state(tree, state);
} else {
start = state->start;
}
goto search_again;
}
/*
* | ---- desired range ---- |
* | state | or | state |
*
* There's a hole, we need to insert something in it and
* ignore the extent we found.
*/
if (state->start > start) {
u64 this_end;
if (end < last_start)
this_end = end;
else
this_end = last_start -1;
err = insert_state(tree, prealloc, start, this_end,
bits);
BUG_ON(err == -EEXIST);
prealloc = NULL;
if (err)
goto out;
start = this_end + 1;
goto search_again;
}
/*
* | ---- desired range ---- |
* | ---------- state ---------- |
* We need to split the extent, and set the bit
* on the first half
*/
set = state->state & bits;
err = split_state(tree, state, prealloc, end + 1);
BUG_ON(err == -EEXIST);
state->state |= bits;
merge_state(tree, prealloc);
prealloc = NULL;
out:
if (prealloc)
free_extent_state(prealloc);
return err;
search_again:
if (start > end)
goto out;
goto again;
}
int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return set_extent_bits(tree, start, end, EXTENT_DIRTY, mask);
}
int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
gfp_t mask)
{
return clear_extent_bits(tree, start, end, EXTENT_DIRTY, mask);
}
int find_first_extent_bit(struct extent_map_tree *tree, u64 start,
u64 *start_ret, u64 *end_ret, int bits)
{
struct cache_extent *node;
struct extent_state *state;
int ret = 1;
/*
* this search will find all the extents that end after
* our range starts.
*/
node = find_first_cache_extent(&tree->state, start);
if (!node)
goto out;
while(1) {
state = container_of(node, struct extent_state, cache_node);
if (state->end >= start && (state->state & bits)) {
*start_ret = state->start;
*end_ret = state->end;
ret = 0;
break;
}
node = next_cache_extent(node);
if (!node)
break;
}
out:
return ret;
}
int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end,
int bits, int filled)
{
struct extent_state *state = NULL;
struct cache_extent *node;
int bitset = 0;
node = find_first_cache_extent(&tree->state, start);
while (node && start <= end) {
state = container_of(node, struct extent_state, cache_node);
if (filled && state->start > start) {
bitset = 0;
break;
}
if (state->start > end)
break;
if (state->state & bits) {
bitset = 1;
if (!filled)
break;
} else if (filled) {
bitset = 0;
break;
}
start = state->end + 1;
if (start > end)
break;
node = next_cache_extent(node);
}
return bitset;
}
int set_state_private(struct extent_map_tree *tree, u64 start, u64 private)
{
struct cache_extent *node;
struct extent_state *state;
int ret = 0;
node = find_first_cache_extent(&tree->state, start);
if (!node) {
ret = -ENOENT;
goto out;
}
state = container_of(node, struct extent_state, cache_node);
if (state->start != start) {
ret = -ENOENT;
goto out;
}
state->private = private;
out:
return ret;
}
int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private)
{
struct cache_extent *node;
struct extent_state *state;
int ret = 0;
node = find_first_cache_extent(&tree->state, start);
if (!node) {
ret = -ENOENT;
goto out;
}
state = container_of(node, struct extent_state, cache_node);
if (state->start != start) {
ret = -ENOENT;
goto out;
}
*private = state->private;
out:
return ret;
}
static int free_some_buffers(struct extent_map_tree *tree)
{
u32 nrscan = 0;
struct extent_buffer *eb;
struct list_head *node, *next;
if (tree->cache_size < cache_max)
return 0;
list_for_each_safe(node, next, &tree->lru) {
eb = list_entry(node, struct extent_buffer, lru);
if (eb->refs == 1) {
free_extent_buffer(eb);
if (tree->cache_size < cache_max)
break;
}
if (nrscan++ > 64)
break;
}
return 0;
}
static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree,
u64 bytenr, u32 blocksize)
{
struct extent_buffer *eb;
int ret;
eb = malloc(sizeof(struct extent_buffer) + blocksize);
if (!eb)
return NULL;
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_map_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_map_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_map_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_map_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 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_map_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_map_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);
}