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btrfs-progs/extent_io.c

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/*
* 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_io.h"
#include "list.h"
#include "ctree.h"
#include "volumes.h"
static u64 cache_soft_max = 1024 * 1024 * 256;
static u64 cache_hard_max = 1 * 1024 * 1024 * 1024;
void extent_io_tree_init(struct extent_io_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->cache_node.objectid = 0;
state->refs = 1;
state->state = 0;
state->xprivate = 0;
return state;
}
static void btrfs_free_extent_state(struct extent_state *state)
{
state->refs--;
BUG_ON(state->refs < 0);
if (state->refs == 0)
free(state);
}
static void free_extent_state_func(struct cache_extent *cache)
{
struct extent_state *es;
es = container_of(cache, struct extent_state, cache_node);
btrfs_free_extent_state(es);
}
void extent_io_tree_cleanup(struct extent_io_tree *tree)
{
struct extent_buffer *eb;
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 %llu len %u\n",
(unsigned long long)eb->start, eb->len);
eb->refs = 1;
}
free_extent_buffer(eb);
}
cache_tree_free_extents(&tree->state, free_extent_state_func);
}
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_io_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);
btrfs_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);
btrfs_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_io_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_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_io_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_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_io_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);
btrfs_free_extent_state(state);
} else {
merge_state(tree, state);
}
return ret;
}
/*
* clear some bits on a range in the tree.
*/
int clear_extent_bits(struct extent_io_tree *tree, u64 start,
u64 end, int bits, gfp_t mask)
{
struct extent_state *state;
struct extent_state *prealloc = NULL;
struct cache_extent *node;
u64 last_end;
int err;
int set = 0;
again:
if (!prealloc) {
prealloc = alloc_extent_state();
if (!prealloc)
return -ENOMEM;
}
/*
* this search will find the extents that end after
* our range starts
*/
node = search_cache_extent(&tree->state, start);
if (!node)
goto out;
state = container_of(node, struct extent_state, cache_node);
if (state->start > end)
goto out;
last_end = state->end;
/*
* | ---- 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) {
set |= clear_state_bit(tree, state, bits);
if (last_end == (u64)-1)
goto out;
start = last_end + 1;
} 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);
if (last_end == (u64)-1)
goto out;
start = last_end + 1;
goto search_again;
out:
if (prealloc)
btrfs_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_io_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;
u64 last_start;
u64 last_end;
again:
if (!prealloc) {
prealloc = alloc_extent_state();
if (!prealloc)
return -ENOMEM;
}
/*
* this search will find the extents that end after
* our range starts
*/
node = search_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) {
state->state |= bits;
merge_state(tree, state);
if (last_end == (u64)-1)
goto out;
start = last_end + 1;
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) {
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);
if (last_end == (u64)-1)
goto out;
start = last_end + 1;
} 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
*/
err = split_state(tree, state, prealloc, end + 1);
BUG_ON(err == -EEXIST);
state->state |= bits;
merge_state(tree, prealloc);
prealloc = NULL;
out:
if (prealloc)
btrfs_free_extent_state(prealloc);
return err;
search_again:
if (start > end)
goto out;
goto again;
}
int set_extent_dirty(struct extent_io_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_io_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_io_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 = search_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_io_tree *tree, u64 start, u64 end,
int bits, int filled)
{
struct extent_state *state = NULL;
struct cache_extent *node;
int bitset = 0;
node = search_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);
if (!node) {
if (filled)
bitset = 0;
break;
}
}
return bitset;
}
int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
{
struct cache_extent *node;
struct extent_state *state;
int ret = 0;
node = search_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->xprivate = private;
out:
return ret;
}
int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
{
struct cache_extent *node;
struct extent_state *state;
int ret = 0;
node = search_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->xprivate;
out:
return ret;
}
static int free_some_buffers(struct extent_io_tree *tree)
{
u32 nrscan = 0;
struct extent_buffer *eb;
struct list_head *node, *next;
if (tree->cache_size < cache_soft_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_hard_max)
break;
} else {
list_move_tail(&eb->lru, &tree->lru);
}
if (nrscan++ > 64 && tree->cache_size < cache_hard_max)
break;
}
return 0;
}
static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
u64 bytenr, u32 blocksize)
{
struct extent_buffer *eb;
int ret;
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;
INIT_LIST_HEAD(&eb->recow);
free_some_buffers(tree);
ret = insert_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);
list_del_init(&eb->recow);
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 = lookup_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 = search_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 = lookup_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);
free_extent_buffer(eb);
}
eb = __alloc_extent_buffer(tree, bytenr, blocksize);
}
return eb;
}
int read_extent_from_disk(struct extent_buffer *eb,
unsigned long offset, unsigned long len)
{
int ret;
ret = pread(eb->fd, eb->data + offset, len, eb->dev_bytenr);
if (ret < 0)
goto out;
if (ret != 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 read_data_from_disk(struct btrfs_fs_info *info, void *buf, u64 offset,
u64 bytes, int mirror)
{
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
u64 bytes_left = bytes;
u64 read_len;
u64 total_read = 0;
int ret;
while (bytes_left) {
read_len = bytes_left;
ret = btrfs_map_block(&info->mapping_tree, READ, offset,
&read_len, &multi, mirror, NULL);
if (ret) {
fprintf(stderr, "Couldn't map the block %Lu\n",
offset);
return -EIO;
}
device = multi->stripes[0].dev;
read_len = min(bytes_left, read_len);
if (device->fd == 0) {
kfree(multi);
return -EIO;
}
ret = pread(device->fd, buf + total_read, read_len,
multi->stripes[0].physical);
kfree(multi);
if (ret < 0) {
fprintf(stderr, "Error reading %Lu, %d\n", offset,
ret);
return ret;
}
if (ret != read_len) {
fprintf(stderr, "Short read for %Lu, read %d, "
"read_len %Lu\n", offset, ret, read_len);
return -EIO;
}
bytes_left -= read_len;
offset += read_len;
total_read += read_len;
}
return 0;
}
int write_data_to_disk(struct btrfs_fs_info *info, void *buf, u64 offset,
u64 bytes, int mirror)
{
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
u64 bytes_left = bytes;
u64 this_len;
u64 total_write = 0;
u64 *raid_map = NULL;
u64 dev_bytenr;
int dev_nr;
int ret = 0;
while (bytes_left > 0) {
this_len = bytes_left;
dev_nr = 0;
ret = btrfs_map_block(&info->mapping_tree, WRITE, offset,
&this_len, &multi, mirror, &raid_map);
if (ret) {
fprintf(stderr, "Couldn't map the block %Lu\n",
offset);
return -EIO;
}
if (raid_map) {
struct extent_buffer *eb;
u64 stripe_len = this_len;
this_len = min(this_len, bytes_left);
this_len = min(this_len, (u64)info->tree_root->leafsize);
eb = malloc(sizeof(struct extent_buffer) + this_len);
BUG_ON(!eb);
memset(eb, 0, sizeof(struct extent_buffer) + this_len);
eb->start = offset;
eb->len = this_len;
memcpy(eb->data, buf + total_write, this_len);
ret = write_raid56_with_parity(info, eb, multi,
stripe_len, raid_map);
BUG_ON(ret);
free(eb);
kfree(raid_map);
raid_map = NULL;
} else while (dev_nr < multi->num_stripes) {
device = multi->stripes[dev_nr].dev;
if (device->fd == 0) {
kfree(multi);
return -EIO;
}
dev_bytenr = multi->stripes[dev_nr].physical;
this_len = min(this_len, bytes_left);
dev_nr++;
ret = pwrite(device->fd, buf + total_write, this_len, dev_bytenr);
if (ret != this_len) {
if (ret < 0) {
fprintf(stderr, "Error writing to "
"device %d\n", errno);
ret = errno;
kfree(multi);
return ret;
} else {
fprintf(stderr, "Short write\n");
kfree(multi);
return -EIO;
}
}
}
BUG_ON(bytes_left < this_len);
bytes_left -= this_len;
offset += this_len;
total_write += this_len;
kfree(multi);
multi = NULL;
}
return 0;
}
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)
return 0;
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 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);
}
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