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/*
* dedupe.c
*
* Copyright (C) 2013 SUSE. 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 version 2 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.
*
* Authors: Mark Fasheh <mfasheh@suse.de>
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <sys/vfs.h>
#include <sys/ioctl.h>
#include <errno.h>
#include "kernel.h"
#include "list.h"
#include "filerec.h"
#include "dedupe.h"
#include "debug.h"
static int must_align_len = 0;
struct dedupe_req {
struct filerec *req_file;
struct list_head req_list; /* see comment in dedupe.h */
uint64_t req_loff;
uint64_t req_total; /* total bytes processed by kernel */
int req_status;
int req_idx; /* index into same->info */
};
static struct dedupe_req *new_dedupe_req(struct filerec *file, uint64_t loff)
{
struct dedupe_req *req = calloc(1, sizeof(*req));
if (req) {
INIT_LIST_HEAD(&req->req_list);
req->req_file = file;
req->req_loff = loff;
}
return req;
}
static void free_dedupe_req(struct dedupe_req *req)
{
if (req) {
if (!list_empty(&req->req_list)) {
struct filerec *file = req->req_file;
fprintf(stderr,
"%s: freeing request with nonempty list\n",
file ? file->filename : "(null)");
list_del(&req->req_list);
}
free(req);
}
}
static struct dedupe_req *same_idx_to_request(struct dedupe_ctxt *ctxt, int idx)
{
int i;
struct dedupe_req *req;
struct list_head *lists[3] = { &ctxt->queued,
&ctxt->in_progress,
&ctxt->completed, };
for (i = 0; i < 3; i++) {
list_for_each_entry(req, lists[i], req_list) {
if (req->req_idx == idx)
return req;
}
}
return NULL;
}
#define _PRE "(dedupe) "
static void print_btrfs_same_info(struct dedupe_ctxt *ctxt)
{
int i;
struct filerec *file = ctxt->ioctl_file;
struct file_dedupe_range *same = ctxt->same;
struct file_dedupe_range_info *info;
struct dedupe_req *req;
dprintf(_PRE"btrfs same info: ioctl_file: \"%s\"\n",
file ? file->filename : "(null)");
dprintf(_PRE"logical_offset: %llu, length: %llu, dest_count: %u\n",
(unsigned long long)same->src_offset,
(unsigned long long)same->src_length, same->dest_count);
for (i = 0; i < same->dest_count; i++) {
info = &same->info[i];
req = same_idx_to_request(ctxt, i);
file = req->req_file;
dprintf(_PRE"info[%d]: name: \"%s\", fd: %lld, logical_offset: "
"%llu, bytes_deduped: %llu, status: %d\n",
i, file ? file->filename : "(null)", (long long)info->dest_fd,
(unsigned long long)info->dest_offset,
(unsigned long long)info->bytes_deduped, info->status);
}
}
static void clear_lists(struct dedupe_ctxt *ctxt)
{
int i;
struct list_head *lists[3] = { &ctxt->queued,
&ctxt->in_progress,
&ctxt->completed, };
struct dedupe_req *req, *tmp;
for (i = 0; i < 3; i++) {
list_for_each_entry_safe(req, tmp, lists[i], req_list) {
list_del_init(&req->req_list);
free_dedupe_req(req);
}
}
}
void free_dedupe_ctxt(struct dedupe_ctxt *ctxt)
{
if (ctxt) {
clear_lists(ctxt);
if (ctxt->same)
free(ctxt->same);
free(ctxt);
}
}
static unsigned int get_fs_blocksize(struct filerec *file)
{
int ret;
struct statfs fs;
static int bsize_warned = 0;
ret = fstatfs(file->fd, &fs);
if (ret) {
if (!bsize_warned) {
fprintf(stderr, "Error %d (\"%s\") while getting fs "
"blocksize, defaulting to 4096 bytes for this "
"dedupe.\n", errno, strerror(errno));
bsize_warned = 1;
}
return 4096;
}
return fs.f_bsize;
}
struct dedupe_ctxt *new_dedupe_ctxt(unsigned int max_extents, uint64_t loff,
uint64_t elen, struct filerec *ioctl_file)
{
struct dedupe_ctxt *ctxt = calloc(1, sizeof(*ctxt));
struct file_dedupe_range *same;
unsigned int same_size;
unsigned int max_dest_files;
if (ctxt == NULL)
return NULL;
if (max_extents > MAX_DEDUPES_PER_IOCTL)
max_extents = MAX_DEDUPES_PER_IOCTL;
max_dest_files = max_extents - 1;
same_size = sizeof(*same) +
max_dest_files * sizeof(struct file_dedupe_range_info);
same = calloc(1, same_size);
if (same == NULL) {
free(same);
free(ctxt);
return NULL;
}
ctxt->same = same;
ctxt->same_size = same_size;
ctxt->max_queable = max_dest_files;
ctxt->len = ctxt->orig_len = elen;
ctxt->ioctl_file = ioctl_file;
ctxt->ioctl_file_off = ctxt->orig_file_off = loff;
INIT_LIST_HEAD(&ctxt->queued);
INIT_LIST_HEAD(&ctxt->in_progress);
INIT_LIST_HEAD(&ctxt->completed);
ctxt->fs_blocksize = get_fs_blocksize(ioctl_file);
return ctxt;
}
int add_extent_to_dedupe(struct dedupe_ctxt *ctxt, uint64_t loff,
struct filerec *file)
{
struct dedupe_req *req = new_dedupe_req(file, loff);
abort_on(ctxt->num_queued >= ctxt->max_queable);
if (req == NULL)
return -1;
list_add_tail(&req->req_list, &ctxt->queued);
ctxt->num_queued++;
return ctxt->max_queable - ctxt->num_queued;
}
static void add_dedupe_request(struct dedupe_ctxt *ctxt,
struct file_dedupe_range *same,
struct dedupe_req *req)
{
int same_idx = same->dest_count;
struct file_dedupe_range_info *info;
struct filerec *file = req->req_file;
abort_on(same->dest_count >= ctxt->max_queable);
req->req_idx = same_idx;
info = &same->info[same_idx];
info->dest_fd = file->fd;
info->dest_offset = req->req_loff;
info->bytes_deduped = 0;
same->dest_count++;
dprintf("add ioctl request %s, off: %llu, dest: %d\n", file->filename,
(unsigned long long)req->req_loff, same->dest_count);
}
static void set_aligned_same_length(struct dedupe_ctxt *ctxt,
struct file_dedupe_range *same)
{
same->src_length = ctxt->len;
if (must_align_len && ctxt->len > ctxt->fs_blocksize)
same->src_length = ctxt->len & ~(ctxt->fs_blocksize - 1);
}
static void populate_dedupe_request(struct dedupe_ctxt *ctxt,
struct file_dedupe_range *same)
{
struct dedupe_req *req, *tmp;
memset(same, 0, ctxt->same_size);
set_aligned_same_length(ctxt, same);
same->src_offset = ctxt->ioctl_file_off;
list_for_each_entry_safe(req, tmp, &ctxt->queued, req_list) {
add_dedupe_request(ctxt, same, req);
list_move_tail(&req->req_list, &ctxt->in_progress);
ctxt->num_queued--;
}
}
/* Returns 1 when there are no more dedupes to process. */
static void process_dedupes(struct dedupe_ctxt *ctxt,
struct file_dedupe_range *same)
{
int same_idx;
uint64_t max_deduped = 0;
struct file_dedupe_range_info *info;
struct dedupe_req *req, *tmp;
list_for_each_entry_safe(req, tmp, &ctxt->in_progress, req_list) {
same_idx = req->req_idx;
info = &same->info[same_idx];
if (info->bytes_deduped > max_deduped)
max_deduped = info->bytes_deduped;
req->req_loff += info->bytes_deduped;
req->req_total += info->bytes_deduped;
if (info->status || req->req_total >= ctxt->orig_len) {
/*
* Only bother taking the final status (the
* rest will be 0)
*/
req->req_status = info->status;
list_move_tail(&req->req_list, &ctxt->completed);
} else {
/*
* put us back on the queued list for another
* go around
*/
list_move_tail(&req->req_list, &ctxt->queued);
ctxt->num_queued++;
}
}
/* Increment our ioctl file pointers */
ctxt->len -= max_deduped;
ctxt->ioctl_file_off += max_deduped;
if (ctxt->len < ctxt->fs_blocksize && must_align_len) {
/*
* If we go around again in this situation, we'll just
* get -EINVAL on all the fds. Short circuit this then
* by moving everything off the queued list.
*/
list_splice_init(&ctxt->queued, &ctxt->completed);
}
}
int dedupe_extents(struct dedupe_ctxt *ctxt)
{
int ret = 0;
while (!list_empty(&ctxt->queued)) {
/* Convert the queued list into an actual request */
populate_dedupe_request(ctxt, ctxt->same);
retry:
ret = ioctl(ctxt->ioctl_file->fd, FIDEDUPERANGE, ctxt->same);
if (ret)
break;
if (debug)
print_btrfs_same_info(ctxt);
if (ctxt->same->info[0].status == -EINVAL && !must_align_len) {
must_align_len = 1;
set_aligned_same_length(ctxt, ctxt->same);
goto retry;
}
process_dedupes(ctxt, ctxt->same);
}
return ret;
}
/*
* Returns 1 when we have no more items.
*/
int pop_one_dedupe_result(struct dedupe_ctxt *ctxt, int *status,
uint64_t *off, uint64_t *bytes_deduped,
struct filerec **file)
{
struct dedupe_req *req;
/*
* We should not be called if dedupe_extents wasn't called or if
* we already passed back all the results..
*/
abort_on(list_empty(&ctxt->completed));
req = list_entry(ctxt->completed.next, struct dedupe_req, req_list);
list_del_init(&req->req_list);
*status = req->req_status;
*off = req->req_loff - req->req_total;
*bytes_deduped = req->req_total;
*file = req->req_file;
free_dedupe_req(req);
return !!list_empty(&ctxt->completed);
}
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