qemu/block/blkverify.c

384 lines
10 KiB
C

/*
* Block protocol for block driver correctness testing
*
* Copyright (C) 2010 IBM, Corp.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include <stdarg.h>
#include "qemu_socket.h" /* for EINPROGRESS on Windows */
#include "block_int.h"
typedef struct {
BlockDriverState *test_file;
} BDRVBlkverifyState;
typedef struct BlkverifyAIOCB BlkverifyAIOCB;
struct BlkverifyAIOCB {
BlockDriverAIOCB common;
QEMUBH *bh;
/* Request metadata */
bool is_write;
int64_t sector_num;
int nb_sectors;
int ret; /* first completed request's result */
unsigned int done; /* completion counter */
bool *finished; /* completion signal for cancel */
QEMUIOVector *qiov; /* user I/O vector */
QEMUIOVector raw_qiov; /* cloned I/O vector for raw file */
void *buf; /* buffer for raw file I/O */
void (*verify)(BlkverifyAIOCB *acb);
};
static void blkverify_aio_cancel(BlockDriverAIOCB *blockacb)
{
BlkverifyAIOCB *acb = (BlkverifyAIOCB *)blockacb;
bool finished = false;
/* Wait until request completes, invokes its callback, and frees itself */
acb->finished = &finished;
while (!finished) {
qemu_aio_wait();
}
}
static AIOPool blkverify_aio_pool = {
.aiocb_size = sizeof(BlkverifyAIOCB),
.cancel = blkverify_aio_cancel,
};
static void GCC_FMT_ATTR(2, 3) blkverify_err(BlkverifyAIOCB *acb,
const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fprintf(stderr, "blkverify: %s sector_num=%" PRId64 " nb_sectors=%d ",
acb->is_write ? "write" : "read", acb->sector_num,
acb->nb_sectors);
vfprintf(stderr, fmt, ap);
fprintf(stderr, "\n");
va_end(ap);
exit(1);
}
/* Valid blkverify filenames look like blkverify:path/to/raw_image:path/to/image */
static int blkverify_open(BlockDriverState *bs, const char *filename, int flags)
{
BDRVBlkverifyState *s = bs->opaque;
int ret;
char *raw, *c;
/* Parse the blkverify: prefix */
if (strncmp(filename, "blkverify:", strlen("blkverify:"))) {
return -EINVAL;
}
filename += strlen("blkverify:");
/* Parse the raw image filename */
c = strchr(filename, ':');
if (c == NULL) {
return -EINVAL;
}
raw = strdup(filename);
raw[c - filename] = '\0';
ret = bdrv_file_open(&bs->file, raw, flags);
free(raw);
if (ret < 0) {
return ret;
}
filename = c + 1;
/* Open the test file */
s->test_file = bdrv_new("");
ret = bdrv_open(s->test_file, filename, flags, NULL);
if (ret < 0) {
bdrv_delete(s->test_file);
s->test_file = NULL;
return ret;
}
return 0;
}
static void blkverify_close(BlockDriverState *bs)
{
BDRVBlkverifyState *s = bs->opaque;
bdrv_delete(s->test_file);
s->test_file = NULL;
}
static int blkverify_flush(BlockDriverState *bs)
{
BDRVBlkverifyState *s = bs->opaque;
/* Only flush test file, the raw file is not important */
return bdrv_flush(s->test_file);
}
static int64_t blkverify_getlength(BlockDriverState *bs)
{
BDRVBlkverifyState *s = bs->opaque;
return bdrv_getlength(s->test_file);
}
/**
* Check that I/O vector contents are identical
*
* @a: I/O vector
* @b: I/O vector
* @ret: Offset to first mismatching byte or -1 if match
*/
static ssize_t blkverify_iovec_compare(QEMUIOVector *a, QEMUIOVector *b)
{
int i;
ssize_t offset = 0;
assert(a->niov == b->niov);
for (i = 0; i < a->niov; i++) {
size_t len = 0;
uint8_t *p = (uint8_t *)a->iov[i].iov_base;
uint8_t *q = (uint8_t *)b->iov[i].iov_base;
assert(a->iov[i].iov_len == b->iov[i].iov_len);
while (len < a->iov[i].iov_len && *p++ == *q++) {
len++;
}
offset += len;
if (len != a->iov[i].iov_len) {
return offset;
}
}
return -1;
}
typedef struct {
int src_index;
struct iovec *src_iov;
void *dest_base;
} IOVectorSortElem;
static int sortelem_cmp_src_base(const void *a, const void *b)
{
const IOVectorSortElem *elem_a = a;
const IOVectorSortElem *elem_b = b;
/* Don't overflow */
if (elem_a->src_iov->iov_base < elem_b->src_iov->iov_base) {
return -1;
} else if (elem_a->src_iov->iov_base > elem_b->src_iov->iov_base) {
return 1;
} else {
return 0;
}
}
static int sortelem_cmp_src_index(const void *a, const void *b)
{
const IOVectorSortElem *elem_a = a;
const IOVectorSortElem *elem_b = b;
return elem_a->src_index - elem_b->src_index;
}
/**
* Copy contents of I/O vector
*
* The relative relationships of overlapping iovecs are preserved. This is
* necessary to ensure identical semantics in the cloned I/O vector.
*/
static void blkverify_iovec_clone(QEMUIOVector *dest, const QEMUIOVector *src,
void *buf)
{
IOVectorSortElem sortelems[src->niov];
void *last_end;
int i;
/* Sort by source iovecs by base address */
for (i = 0; i < src->niov; i++) {
sortelems[i].src_index = i;
sortelems[i].src_iov = &src->iov[i];
}
qsort(sortelems, src->niov, sizeof(sortelems[0]), sortelem_cmp_src_base);
/* Allocate buffer space taking into account overlapping iovecs */
last_end = NULL;
for (i = 0; i < src->niov; i++) {
struct iovec *cur = sortelems[i].src_iov;
ptrdiff_t rewind = 0;
/* Detect overlap */
if (last_end && last_end > cur->iov_base) {
rewind = last_end - cur->iov_base;
}
sortelems[i].dest_base = buf - rewind;
buf += cur->iov_len - MIN(rewind, cur->iov_len);
last_end = MAX(cur->iov_base + cur->iov_len, last_end);
}
/* Sort by source iovec index and build destination iovec */
qsort(sortelems, src->niov, sizeof(sortelems[0]), sortelem_cmp_src_index);
for (i = 0; i < src->niov; i++) {
qemu_iovec_add(dest, sortelems[i].dest_base, src->iov[i].iov_len);
}
}
static BlkverifyAIOCB *blkverify_aio_get(BlockDriverState *bs, bool is_write,
int64_t sector_num, QEMUIOVector *qiov,
int nb_sectors,
BlockDriverCompletionFunc *cb,
void *opaque)
{
BlkverifyAIOCB *acb = qemu_aio_get(&blkverify_aio_pool, bs, cb, opaque);
acb->bh = NULL;
acb->is_write = is_write;
acb->sector_num = sector_num;
acb->nb_sectors = nb_sectors;
acb->ret = -EINPROGRESS;
acb->done = 0;
acb->qiov = qiov;
acb->buf = NULL;
acb->verify = NULL;
acb->finished = NULL;
return acb;
}
static void blkverify_aio_bh(void *opaque)
{
BlkverifyAIOCB *acb = opaque;
qemu_bh_delete(acb->bh);
if (acb->buf) {
qemu_iovec_destroy(&acb->raw_qiov);
qemu_vfree(acb->buf);
}
acb->common.cb(acb->common.opaque, acb->ret);
if (acb->finished) {
*acb->finished = true;
}
qemu_aio_release(acb);
}
static void blkverify_aio_cb(void *opaque, int ret)
{
BlkverifyAIOCB *acb = opaque;
switch (++acb->done) {
case 1:
acb->ret = ret;
break;
case 2:
if (acb->ret != ret) {
blkverify_err(acb, "return value mismatch %d != %d", acb->ret, ret);
}
if (acb->verify) {
acb->verify(acb);
}
acb->bh = qemu_bh_new(blkverify_aio_bh, acb);
qemu_bh_schedule(acb->bh);
break;
}
}
static void blkverify_verify_readv(BlkverifyAIOCB *acb)
{
ssize_t offset = blkverify_iovec_compare(acb->qiov, &acb->raw_qiov);
if (offset != -1) {
blkverify_err(acb, "contents mismatch in sector %" PRId64,
acb->sector_num + (int64_t)(offset / BDRV_SECTOR_SIZE));
}
}
static BlockDriverAIOCB *blkverify_aio_readv(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVBlkverifyState *s = bs->opaque;
BlkverifyAIOCB *acb = blkverify_aio_get(bs, false, sector_num, qiov,
nb_sectors, cb, opaque);
acb->verify = blkverify_verify_readv;
acb->buf = qemu_blockalign(bs->file, qiov->size);
qemu_iovec_init(&acb->raw_qiov, acb->qiov->niov);
blkverify_iovec_clone(&acb->raw_qiov, qiov, acb->buf);
if (!bdrv_aio_readv(s->test_file, sector_num, qiov, nb_sectors,
blkverify_aio_cb, acb)) {
blkverify_aio_cb(acb, -EIO);
}
if (!bdrv_aio_readv(bs->file, sector_num, &acb->raw_qiov, nb_sectors,
blkverify_aio_cb, acb)) {
blkverify_aio_cb(acb, -EIO);
}
return &acb->common;
}
static BlockDriverAIOCB *blkverify_aio_writev(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVBlkverifyState *s = bs->opaque;
BlkverifyAIOCB *acb = blkverify_aio_get(bs, true, sector_num, qiov,
nb_sectors, cb, opaque);
if (!bdrv_aio_writev(s->test_file, sector_num, qiov, nb_sectors,
blkverify_aio_cb, acb)) {
blkverify_aio_cb(acb, -EIO);
}
if (!bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors,
blkverify_aio_cb, acb)) {
blkverify_aio_cb(acb, -EIO);
}
return &acb->common;
}
static BlockDriverAIOCB *blkverify_aio_flush(BlockDriverState *bs,
BlockDriverCompletionFunc *cb,
void *opaque)
{
BDRVBlkverifyState *s = bs->opaque;
/* Only flush test file, the raw file is not important */
return bdrv_aio_flush(s->test_file, cb, opaque);
}
static BlockDriver bdrv_blkverify = {
.format_name = "blkverify",
.protocol_name = "blkverify",
.instance_size = sizeof(BDRVBlkverifyState),
.bdrv_getlength = blkverify_getlength,
.bdrv_file_open = blkverify_open,
.bdrv_close = blkverify_close,
.bdrv_flush = blkverify_flush,
.bdrv_aio_readv = blkverify_aio_readv,
.bdrv_aio_writev = blkverify_aio_writev,
.bdrv_aio_flush = blkverify_aio_flush,
};
static void bdrv_blkverify_init(void)
{
bdrv_register(&bdrv_blkverify);
}
block_init(bdrv_blkverify_init);