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15dc2697a5
qemu/block.c
Christoph Hellwig 15dc2697a5 block: saner flags filtering in bdrv_open2 
Clean up the current mess about figuring out which flags to pass to the
driver.  BDRV_O_FILE, BDRV_O_SNAPSHOT and BDRV_O_NO_BACKING are flags
only used by the block layer internally so filter them out directly.
Previously BDRV_O_NO_BACKING could accidentally be passed to the drivers,
but wasn't ever used.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-02-10 11:57:03 -06:00

2224 lines
60 KiB
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/*
* QEMU System Emulator block driver
*
* Copyright (c) 2003 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "config-host.h"
#include "qemu-common.h"
#include "monitor.h"
#include "block_int.h"
#include "module.h"
#include "qemu-objects.h"
#ifdef CONFIG_BSD
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/queue.h>
#ifndef __DragonFly__
#include <sys/disk.h>
#endif
#endif
#ifdef _WIN32
#include <windows.h>
#endif
static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque);
static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors);
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors);
BlockDriverState *bdrv_first;
static BlockDriver *first_drv;
/* If non-zero, use only whitelisted block drivers */
static int use_bdrv_whitelist;
int path_is_absolute(const char *path)
{
const char *p;
#ifdef _WIN32
/* specific case for names like: "\\.\d:" */
if (*path == '/' || *path == '\\')
return 1;
#endif
p = strchr(path, ':');
if (p)
p++;
else
p = path;
#ifdef _WIN32
return (*p == '/' || *p == '\\');
#else
return (*p == '/');
#endif
}
/* if filename is absolute, just copy it to dest. Otherwise, build a
path to it by considering it is relative to base_path. URL are
supported. */
void path_combine(char *dest, int dest_size,
const char *base_path,
const char *filename)
{
const char *p, *p1;
int len;
if (dest_size <= 0)
return;
if (path_is_absolute(filename)) {
pstrcpy(dest, dest_size, filename);
} else {
p = strchr(base_path, ':');
if (p)
p++;
else
p = base_path;
p1 = strrchr(base_path, '/');
#ifdef _WIN32
{
const char *p2;
p2 = strrchr(base_path, '\\');
if (!p1 || p2 > p1)
p1 = p2;
}
#endif
if (p1)
p1++;
else
p1 = base_path;
if (p1 > p)
p = p1;
len = p - base_path;
if (len > dest_size - 1)
len = dest_size - 1;
memcpy(dest, base_path, len);
dest[len] = '\0';
pstrcat(dest, dest_size, filename);
}
}
void bdrv_register(BlockDriver *bdrv)
{
if (!bdrv->bdrv_aio_readv) {
/* add AIO emulation layer */
bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
} else if (!bdrv->bdrv_read) {
/* add synchronous IO emulation layer */
bdrv->bdrv_read = bdrv_read_em;
bdrv->bdrv_write = bdrv_write_em;
}
if (!bdrv->bdrv_aio_flush)
bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
bdrv->next = first_drv;
first_drv = bdrv;
}
/* create a new block device (by default it is empty) */
BlockDriverState *bdrv_new(const char *device_name)
{
BlockDriverState **pbs, *bs;
bs = qemu_mallocz(sizeof(BlockDriverState));
pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
if (device_name[0] != '\0') {
/* insert at the end */
pbs = &bdrv_first;
while (*pbs != NULL)
pbs = &(*pbs)->next;
*pbs = bs;
}
return bs;
}
BlockDriver *bdrv_find_format(const char *format_name)
{
BlockDriver *drv1;
for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
if (!strcmp(drv1->format_name, format_name))
return drv1;
}
return NULL;
}
static int bdrv_is_whitelisted(BlockDriver *drv)
{
static const char *whitelist[] = {
CONFIG_BDRV_WHITELIST
};
const char **p;
if (!whitelist[0])
return 1; /* no whitelist, anything goes */
for (p = whitelist; *p; p++) {
if (!strcmp(drv->format_name, *p)) {
return 1;
}
}
return 0;
}
BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
{
BlockDriver *drv = bdrv_find_format(format_name);
return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
}
int bdrv_create(BlockDriver *drv, const char* filename,
QEMUOptionParameter *options)
{
if (!drv->bdrv_create)
return -ENOTSUP;
return drv->bdrv_create(filename, options);
}
#ifdef _WIN32
void get_tmp_filename(char *filename, int size)
{
char temp_dir[MAX_PATH];
GetTempPath(MAX_PATH, temp_dir);
GetTempFileName(temp_dir, "qem", 0, filename);
}
#else
void get_tmp_filename(char *filename, int size)
{
int fd;
const char *tmpdir;
/* XXX: race condition possible */
tmpdir = getenv("TMPDIR");
if (!tmpdir)
tmpdir = "/tmp";
snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
fd = mkstemp(filename);
close(fd);
}
#endif
#ifdef _WIN32
static int is_windows_drive_prefix(const char *filename)
{
return (((filename[0] >= 'a' && filename[0] <= 'z') ||
(filename[0] >= 'A' && filename[0] <= 'Z')) &&
filename[1] == ':');
}
int is_windows_drive(const char *filename)
{
if (is_windows_drive_prefix(filename) &&
filename[2] == '\0')
return 1;
if (strstart(filename, "\\\\.\\", NULL) ||
strstart(filename, "//./", NULL))
return 1;
return 0;
}
#endif
static BlockDriver *find_protocol(const char *filename)
{
BlockDriver *drv1;
char protocol[128];
int len;
const char *p;
#ifdef _WIN32
if (is_windows_drive(filename) ||
is_windows_drive_prefix(filename))
return bdrv_find_format("raw");
#endif
p = strchr(filename, ':');
if (!p)
return bdrv_find_format("raw");
len = p - filename;
if (len > sizeof(protocol) - 1)
len = sizeof(protocol) - 1;
memcpy(protocol, filename, len);
protocol[len] = '\0';
for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
if (drv1->protocol_name &&
!strcmp(drv1->protocol_name, protocol))
return drv1;
}
return NULL;
}
/*
* Detect host devices. By convention, /dev/cdrom[N] is always
* recognized as a host CDROM.
*/
static BlockDriver *find_hdev_driver(const char *filename)
{
int score_max = 0, score;
BlockDriver *drv = NULL, *d;
for (d = first_drv; d; d = d->next) {
if (d->bdrv_probe_device) {
score = d->bdrv_probe_device(filename);
if (score > score_max) {
score_max = score;
drv = d;
}
}
}
return drv;
}
static BlockDriver *find_image_format(const char *filename)
{
int ret, score, score_max;
BlockDriver *drv1, *drv;
uint8_t buf[2048];
BlockDriverState *bs;
drv = find_protocol(filename);
/* no need to test disk image formats for vvfat */
if (drv && strcmp(drv->format_name, "vvfat") == 0)
return drv;
ret = bdrv_file_open(&bs, filename, 0);
if (ret < 0)
return NULL;
ret = bdrv_pread(bs, 0, buf, sizeof(buf));
bdrv_delete(bs);
if (ret < 0) {
return NULL;
}
score_max = 0;
for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
if (drv1->bdrv_probe) {
score = drv1->bdrv_probe(buf, ret, filename);
if (score > score_max) {
score_max = score;
drv = drv1;
}
}
}
return drv;
}
int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
{
BlockDriverState *bs;
int ret;
bs = bdrv_new("");
ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
if (ret < 0) {
bdrv_delete(bs);
return ret;
}
bs->growable = 1;
*pbs = bs;
return 0;
}
int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
{
return bdrv_open2(bs, filename, flags, NULL);
}
int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
BlockDriver *drv)
{
int ret, open_flags;
char tmp_filename[PATH_MAX];
char backing_filename[PATH_MAX];
bs->is_temporary = 0;
bs->encrypted = 0;
bs->valid_key = 0;
/* buffer_alignment defaulted to 512, drivers can change this value */
bs->buffer_alignment = 512;
if (flags & BDRV_O_SNAPSHOT) {
BlockDriverState *bs1;
int64_t total_size;
int is_protocol = 0;
BlockDriver *bdrv_qcow2;
QEMUOptionParameter *options;
/* if snapshot, we create a temporary backing file and open it
instead of opening 'filename' directly */
/* if there is a backing file, use it */
bs1 = bdrv_new("");
ret = bdrv_open2(bs1, filename, 0, drv);
if (ret < 0) {
bdrv_delete(bs1);
return ret;
}
total_size = bdrv_getlength(bs1) >> BDRV_SECTOR_BITS;
if (bs1->drv && bs1->drv->protocol_name)
is_protocol = 1;
bdrv_delete(bs1);
get_tmp_filename(tmp_filename, sizeof(tmp_filename));
/* Real path is meaningless for protocols */
if (is_protocol)
snprintf(backing_filename, sizeof(backing_filename),
"%s", filename);
else if (!realpath(filename, backing_filename))
return -errno;
bdrv_qcow2 = bdrv_find_format("qcow2");
options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size * 512);
set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
if (drv) {
set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
drv->format_name);
}
ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
if (ret < 0) {
return ret;
}
filename = tmp_filename;
drv = bdrv_qcow2;
bs->is_temporary = 1;
}
pstrcpy(bs->filename, sizeof(bs->filename), filename);
if (flags & BDRV_O_FILE) {
drv = find_protocol(filename);
} else if (!drv) {
drv = find_hdev_driver(filename);
if (!drv) {
drv = find_image_format(filename);
}
}
if (!drv) {
ret = -ENOENT;
goto unlink_and_fail;
}
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
ret = -ENOTSUP;
goto unlink_and_fail;
}
bs->drv = drv;
bs->opaque = qemu_mallocz(drv->instance_size);
/*
* Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
* write cache to the guest. We do need the fdatasync to flush
* out transactions for block allocations, and we maybe have a
* volatile write cache in our backing device to deal with.
*/
if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
bs->enable_write_cache = 1;
bs->read_only = (flags & BDRV_O_RDWR) == 0;
/*
* Clear flags that are internal to the block layer before opening the
* image.
*/
open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
/*
* Snapshots should be writeable.
*
* XXX(hch): and what is the point of a snapshot during a read-only open?
*/
if (!(flags & BDRV_O_FILE) && bs->is_temporary) {
open_flags |= BDRV_O_RDWR;
}
ret = drv->bdrv_open(bs, filename, open_flags);
if (ret < 0) {
goto free_and_fail;
}
if (drv->bdrv_getlength) {
bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
}
#ifndef _WIN32
if (bs->is_temporary) {
unlink(filename);
}
#endif
if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
/* if there is a backing file, use it */
BlockDriver *back_drv = NULL;
bs->backing_hd = bdrv_new("");
path_combine(backing_filename, sizeof(backing_filename),
filename, bs->backing_file);
if (bs->backing_format[0] != '\0')
back_drv = bdrv_find_format(bs->backing_format);
ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags,
back_drv);
bs->backing_hd->read_only = (open_flags & BDRV_O_RDWR) == 0;
if (ret < 0) {
bdrv_close(bs);
return ret;
}
}
if (!bdrv_key_required(bs)) {
/* call the change callback */
bs->media_changed = 1;
if (bs->change_cb)
bs->change_cb(bs->change_opaque);
}
return 0;
free_and_fail:
qemu_free(bs->opaque);
bs->opaque = NULL;
bs->drv = NULL;
unlink_and_fail:
if (bs->is_temporary)
unlink(filename);
return ret;
}
void bdrv_close(BlockDriverState *bs)
{
if (bs->drv) {
if (bs->backing_hd)
bdrv_delete(bs->backing_hd);
bs->drv->bdrv_close(bs);
qemu_free(bs->opaque);
#ifdef _WIN32
if (bs->is_temporary) {
unlink(bs->filename);
}
#endif
bs->opaque = NULL;
bs->drv = NULL;
/* call the change callback */
bs->media_changed = 1;
if (bs->change_cb)
bs->change_cb(bs->change_opaque);
}
}
void bdrv_delete(BlockDriverState *bs)
{
BlockDriverState **pbs;
pbs = &bdrv_first;
while (*pbs != bs && *pbs != NULL)
pbs = &(*pbs)->next;
if (*pbs == bs)
*pbs = bs->next;
bdrv_close(bs);
qemu_free(bs);
}
/*
* Run consistency checks on an image
*
* Returns the number of errors or -errno when an internal error occurs
*/
int bdrv_check(BlockDriverState *bs)
{
if (bs->drv->bdrv_check == NULL) {
return -ENOTSUP;
}
return bs->drv->bdrv_check(bs);
}
/* commit COW file into the raw image */
int bdrv_commit(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
int64_t i, total_sectors;
int n, j;
int ret = 0;
unsigned char sector[512];
if (!drv)
return -ENOMEDIUM;
if (bs->read_only) {
return -EACCES;
}
if (!bs->backing_hd) {
return -ENOTSUP;
}
total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
for (i = 0; i < total_sectors;) {
if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
for(j = 0; j < n; j++) {
if (bdrv_read(bs, i, sector, 1) != 0) {
return -EIO;
}
if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
return -EIO;
}
i++;
}
} else {
i += n;
}
}
if (drv->bdrv_make_empty) {
ret = drv->bdrv_make_empty(bs);
bdrv_flush(bs);
}
/*
* Make sure all data we wrote to the backing device is actually
* stable on disk.
*/
if (bs->backing_hd)
bdrv_flush(bs->backing_hd);
return ret;
}
/*
* Return values:
* 0 - success
* -EINVAL - backing format specified, but no file
* -ENOSPC - can't update the backing file because no space is left in the
* image file header
* -ENOTSUP - format driver doesn't support changing the backing file
*/
int bdrv_change_backing_file(BlockDriverState *bs,
const char *backing_file, const char *backing_fmt)
{
BlockDriver *drv = bs->drv;
if (drv->bdrv_change_backing_file != NULL) {
return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
} else {
return -ENOTSUP;
}
}
static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
size_t size)
{
int64_t len;
if (!bdrv_is_inserted(bs))
return -ENOMEDIUM;
if (bs->growable)
return 0;
len = bdrv_getlength(bs);
if (offset < 0)
return -EIO;
if ((offset > len) || (len - offset < size))
return -EIO;
return 0;
}
static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
int nb_sectors)
{
return bdrv_check_byte_request(bs, sector_num * 512, nb_sectors * 512);
}
/* return < 0 if error. See bdrv_write() for the return codes */
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (bdrv_check_request(bs, sector_num, nb_sectors))
return -EIO;
return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
}
static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int dirty)
{
int64_t start, end;
unsigned long val, idx, bit;
start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
for (; start <= end; start++) {
idx = start / (sizeof(unsigned long) * 8);
bit = start % (sizeof(unsigned long) * 8);
val = bs->dirty_bitmap[idx];
if (dirty) {
if (!(val & (1 << bit))) {
bs->dirty_count++;
val |= 1 << bit;
}
} else {
if (val & (1 << bit)) {
bs->dirty_count--;
val &= ~(1 << bit);
}
}
bs->dirty_bitmap[idx] = val;
}
}
/* Return < 0 if error. Important errors are:
-EIO generic I/O error (may happen for all errors)
-ENOMEDIUM No media inserted.
-EINVAL Invalid sector number or nb_sectors
-EACCES Trying to write a read-only device
*/
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
BlockDriver *drv = bs->drv;
if (!bs->drv)
return -ENOMEDIUM;
if (bs->read_only)
return -EACCES;
if (bdrv_check_request(bs, sector_num, nb_sectors))
return -EIO;
if (bs->dirty_bitmap) {
set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
}
return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
}
int bdrv_pread(BlockDriverState *bs, int64_t offset,
void *buf, int count1)
{
uint8_t tmp_buf[BDRV_SECTOR_SIZE];
int len, nb_sectors, count;
int64_t sector_num;
int ret;
count = count1;
/* first read to align to sector start */
len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
if (len > count)
len = count;
sector_num = offset >> BDRV_SECTOR_BITS;
if (len > 0) {
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
return ret;
memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
count -= len;
if (count == 0)
return count1;
sector_num++;
buf += len;
}
/* read the sectors "in place" */
nb_sectors = count >> BDRV_SECTOR_BITS;
if (nb_sectors > 0) {
if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
return ret;
sector_num += nb_sectors;
len = nb_sectors << BDRV_SECTOR_BITS;
buf += len;
count -= len;
}
/* add data from the last sector */
if (count > 0) {
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
return ret;
memcpy(buf, tmp_buf, count);
}
return count1;
}
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
const void *buf, int count1)
{
uint8_t tmp_buf[BDRV_SECTOR_SIZE];
int len, nb_sectors, count;
int64_t sector_num;
int ret;
count = count1;
/* first write to align to sector start */
len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
if (len > count)
len = count;
sector_num = offset >> BDRV_SECTOR_BITS;
if (len > 0) {
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
return ret;
memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
return ret;
count -= len;
if (count == 0)
return count1;
sector_num++;
buf += len;
}
/* write the sectors "in place" */
nb_sectors = count >> BDRV_SECTOR_BITS;
if (nb_sectors > 0) {
if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
return ret;
sector_num += nb_sectors;
len = nb_sectors << BDRV_SECTOR_BITS;
buf += len;
count -= len;
}
/* add data from the last sector */
if (count > 0) {
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
return ret;
memcpy(tmp_buf, buf, count);
if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
return ret;
}
return count1;
}
/**
* Truncate file to 'offset' bytes (needed only for file protocols)
*/
int bdrv_truncate(BlockDriverState *bs, int64_t offset)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_truncate)
return -ENOTSUP;
if (bs->read_only)
return -EACCES;
return drv->bdrv_truncate(bs, offset);
}
/**
* Length of a file in bytes. Return < 0 if error or unknown.
*/
int64_t bdrv_getlength(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_getlength) {
/* legacy mode */
return bs->total_sectors * BDRV_SECTOR_SIZE;
}
return drv->bdrv_getlength(bs);
}
/* return 0 as number of sectors if no device present or error */
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
{
int64_t length;
length = bdrv_getlength(bs);
if (length < 0)
length = 0;
else
length = length >> BDRV_SECTOR_BITS;
*nb_sectors_ptr = length;
}
struct partition {
uint8_t boot_ind; /* 0x80 - active */
uint8_t head; /* starting head */
uint8_t sector; /* starting sector */
uint8_t cyl; /* starting cylinder */
uint8_t sys_ind; /* What partition type */
uint8_t end_head; /* end head */
uint8_t end_sector; /* end sector */
uint8_t end_cyl; /* end cylinder */
uint32_t start_sect; /* starting sector counting from 0 */
uint32_t nr_sects; /* nr of sectors in partition */
} __attribute__((packed));
/* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
static int guess_disk_lchs(BlockDriverState *bs,
int *pcylinders, int *pheads, int *psectors)
{
uint8_t buf[512];
int ret, i, heads, sectors, cylinders;
struct partition *p;
uint32_t nr_sects;
uint64_t nb_sectors;
bdrv_get_geometry(bs, &nb_sectors);
ret = bdrv_read(bs, 0, buf, 1);
if (ret < 0)
return -1;
/* test msdos magic */
if (buf[510] != 0x55 || buf[511] != 0xaa)
return -1;
for(i = 0; i < 4; i++) {
p = ((struct partition *)(buf + 0x1be)) + i;
nr_sects = le32_to_cpu(p->nr_sects);
if (nr_sects && p->end_head) {
/* We make the assumption that the partition terminates on
a cylinder boundary */
heads = p->end_head + 1;
sectors = p->end_sector & 63;
if (sectors == 0)
continue;
cylinders = nb_sectors / (heads * sectors);
if (cylinders < 1 || cylinders > 16383)
continue;
*pheads = heads;
*psectors = sectors;
*pcylinders = cylinders;
#if 0
printf("guessed geometry: LCHS=%d %d %d\n",
cylinders, heads, sectors);
#endif
return 0;
}
}
return -1;
}
void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
{
int translation, lba_detected = 0;
int cylinders, heads, secs;
uint64_t nb_sectors;
/* if a geometry hint is available, use it */
bdrv_get_geometry(bs, &nb_sectors);
bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
translation = bdrv_get_translation_hint(bs);
if (cylinders != 0) {
*pcyls = cylinders;
*pheads = heads;
*psecs = secs;
} else {
if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
if (heads > 16) {
/* if heads > 16, it means that a BIOS LBA
translation was active, so the default
hardware geometry is OK */
lba_detected = 1;
goto default_geometry;
} else {
*pcyls = cylinders;
*pheads = heads;
*psecs = secs;
/* disable any translation to be in sync with
the logical geometry */
if (translation == BIOS_ATA_TRANSLATION_AUTO) {
bdrv_set_translation_hint(bs,
BIOS_ATA_TRANSLATION_NONE);
}
}
} else {
default_geometry:
/* if no geometry, use a standard physical disk geometry */
cylinders = nb_sectors / (16 * 63);
if (cylinders > 16383)
cylinders = 16383;
else if (cylinders < 2)
cylinders = 2;
*pcyls = cylinders;
*pheads = 16;
*psecs = 63;
if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
if ((*pcyls * *pheads) <= 131072) {
bdrv_set_translation_hint(bs,
BIOS_ATA_TRANSLATION_LARGE);
} else {
bdrv_set_translation_hint(bs,
BIOS_ATA_TRANSLATION_LBA);
}
}
}
bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
}
}
void bdrv_set_geometry_hint(BlockDriverState *bs,
int cyls, int heads, int secs)
{
bs->cyls = cyls;
bs->heads = heads;
bs->secs = secs;
}
void bdrv_set_type_hint(BlockDriverState *bs, int type)
{
bs->type = type;
bs->removable = ((type == BDRV_TYPE_CDROM ||
type == BDRV_TYPE_FLOPPY));
}
void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
{
bs->translation = translation;
}
void bdrv_get_geometry_hint(BlockDriverState *bs,
int *pcyls, int *pheads, int *psecs)
{
*pcyls = bs->cyls;
*pheads = bs->heads;
*psecs = bs->secs;
}
int bdrv_get_type_hint(BlockDriverState *bs)
{
return bs->type;
}
int bdrv_get_translation_hint(BlockDriverState *bs)
{
return bs->translation;
}
int bdrv_is_removable(BlockDriverState *bs)
{
return bs->removable;
}
int bdrv_is_read_only(BlockDriverState *bs)
{
return bs->read_only;
}
int bdrv_is_sg(BlockDriverState *bs)
{
return bs->sg;
}
int bdrv_enable_write_cache(BlockDriverState *bs)
{
return bs->enable_write_cache;
}
/* XXX: no longer used */
void bdrv_set_change_cb(BlockDriverState *bs,
void (*change_cb)(void *opaque), void *opaque)
{
bs->change_cb = change_cb;
bs->change_opaque = opaque;
}
int bdrv_is_encrypted(BlockDriverState *bs)
{
if (bs->backing_hd && bs->backing_hd->encrypted)
return 1;
return bs->encrypted;
}
int bdrv_key_required(BlockDriverState *bs)
{
BlockDriverState *backing_hd = bs->backing_hd;
if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
return 1;
return (bs->encrypted && !bs->valid_key);
}
int bdrv_set_key(BlockDriverState *bs, const char *key)
{
int ret;
if (bs->backing_hd && bs->backing_hd->encrypted) {
ret = bdrv_set_key(bs->backing_hd, key);
if (ret < 0)
return ret;
if (!bs->encrypted)
return 0;
}
if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
return -1;
ret = bs->drv->bdrv_set_key(bs, key);
if (ret < 0) {
bs->valid_key = 0;
} else if (!bs->valid_key) {
bs->valid_key = 1;
/* call the change callback now, we skipped it on open */
bs->media_changed = 1;
if (bs->change_cb)
bs->change_cb(bs->change_opaque);
}
return ret;
}
void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
{
if (!bs->drv) {
buf[0] = '\0';
} else {
pstrcpy(buf, buf_size, bs->drv->format_name);
}
}
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
void *opaque)
{
BlockDriver *drv;
for (drv = first_drv; drv != NULL; drv = drv->next) {
it(opaque, drv->format_name);
}
}
BlockDriverState *bdrv_find(const char *name)
{
BlockDriverState *bs;
for (bs = bdrv_first; bs != NULL; bs = bs->next) {
if (!strcmp(name, bs->device_name))
return bs;
}
return NULL;
}
void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
{
BlockDriverState *bs;
for (bs = bdrv_first; bs != NULL; bs = bs->next) {
it(opaque, bs);
}
}
const char *bdrv_get_device_name(BlockDriverState *bs)
{
return bs->device_name;
}
void bdrv_flush(BlockDriverState *bs)
{
if (bs->drv && bs->drv->bdrv_flush)
bs->drv->bdrv_flush(bs);
}
void bdrv_flush_all(void)
{
BlockDriverState *bs;
for (bs = bdrv_first; bs != NULL; bs = bs->next)
if (bs->drv && !bdrv_is_read_only(bs) &&
(!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
bdrv_flush(bs);
}
/*
* Returns true iff the specified sector is present in the disk image. Drivers
* not implementing the functionality are assumed to not support backing files,
* hence all their sectors are reported as allocated.
*
* 'pnum' is set to the number of sectors (including and immediately following
* the specified sector) that are known to be in the same
* allocated/unallocated state.
*
* 'nb_sectors' is the max value 'pnum' should be set to.
*/
int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
int *pnum)
{
int64_t n;
if (!bs->drv->bdrv_is_allocated) {
if (sector_num >= bs->total_sectors) {
*pnum = 0;
return 0;
}
n = bs->total_sectors - sector_num;
*pnum = (n < nb_sectors) ? (n) : (nb_sectors);
return 1;
}
return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
}
void bdrv_mon_event(const BlockDriverState *bdrv,
BlockMonEventAction action, int is_read)
{
QObject *data;
const char *action_str;
switch (action) {
case BDRV_ACTION_REPORT:
action_str = "report";
break;
case BDRV_ACTION_IGNORE:
action_str = "ignore";
break;
case BDRV_ACTION_STOP:
action_str = "stop";
break;
default:
abort();
}
data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
bdrv->device_name,
action_str,
is_read ? "read" : "write");
monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
qobject_decref(data);
}
static void bdrv_print_dict(QObject *obj, void *opaque)
{
QDict *bs_dict;
Monitor *mon = opaque;
bs_dict = qobject_to_qdict(obj);
monitor_printf(mon, "%s: type=%s removable=%d",
qdict_get_str(bs_dict, "device"),
qdict_get_str(bs_dict, "type"),
qdict_get_bool(bs_dict, "removable"));
if (qdict_get_bool(bs_dict, "removable")) {
monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
}
if (qdict_haskey(bs_dict, "inserted")) {
QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
monitor_printf(mon, " file=");
monitor_print_filename(mon, qdict_get_str(qdict, "file"));
if (qdict_haskey(qdict, "backing_file")) {
monitor_printf(mon, " backing_file=");
monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
}
monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
qdict_get_bool(qdict, "ro"),
qdict_get_str(qdict, "drv"),
qdict_get_bool(qdict, "encrypted"));
} else {
monitor_printf(mon, " [not inserted]");
}
monitor_printf(mon, "\n");
}
void bdrv_info_print(Monitor *mon, const QObject *data)
{
qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
}
/**
* bdrv_info(): Block devices information
*
* Each block device information is stored in a QDict and the
* returned QObject is a QList of all devices.
*
* The QDict contains the following:
*
* - "device": device name
* - "type": device type
* - "removable": true if the device is removable, false otherwise
* - "locked": true if the device is locked, false otherwise
* - "inserted": only present if the device is inserted, it is a QDict
* containing the following:
* - "file": device file name
* - "ro": true if read-only, false otherwise
* - "drv": driver format name
* - "backing_file": backing file name if one is used
* - "encrypted": true if encrypted, false otherwise
*
* Example:
*
* [ { "device": "ide0-hd0", "type": "hd", "removable": false, "locked": false,
* "inserted": { "file": "/tmp/foobar", "ro": false, "drv": "qcow2" } },
* { "device": "floppy0", "type": "floppy", "removable": true,
* "locked": false } ]
*/
void bdrv_info(Monitor *mon, QObject **ret_data)
{
QList *bs_list;
BlockDriverState *bs;
bs_list = qlist_new();
for (bs = bdrv_first; bs != NULL; bs = bs->next) {
QObject *bs_obj;
const char *type = "unknown";
switch(bs->type) {
case BDRV_TYPE_HD:
type = "hd";
break;
case BDRV_TYPE_CDROM:
type = "cdrom";
break;
case BDRV_TYPE_FLOPPY:
type = "floppy";
break;
}
bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
"'removable': %i, 'locked': %i }",
bs->device_name, type, bs->removable,
bs->locked);
assert(bs_obj != NULL);
if (bs->drv) {
QObject *obj;
QDict *bs_dict = qobject_to_qdict(bs_obj);
obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
"'encrypted': %i }",
bs->filename, bs->read_only,
bs->drv->format_name,
bdrv_is_encrypted(bs));
assert(obj != NULL);
if (bs->backing_file[0] != '\0') {
QDict *qdict = qobject_to_qdict(obj);
qdict_put(qdict, "backing_file",
qstring_from_str(bs->backing_file));
}
qdict_put_obj(bs_dict, "inserted", obj);
}
qlist_append_obj(bs_list, bs_obj);
}
*ret_data = QOBJECT(bs_list);
}
static void bdrv_stats_iter(QObject *data, void *opaque)
{
QDict *qdict;
Monitor *mon = opaque;
qdict = qobject_to_qdict(data);
monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
monitor_printf(mon, " rd_bytes=%" PRId64
" wr_bytes=%" PRId64
" rd_operations=%" PRId64
" wr_operations=%" PRId64
"\n",
qdict_get_int(qdict, "rd_bytes"),
qdict_get_int(qdict, "wr_bytes"),
qdict_get_int(qdict, "rd_operations"),
qdict_get_int(qdict, "wr_operations"));
}
void bdrv_stats_print(Monitor *mon, const QObject *data)
{
qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
}
/**
* bdrv_info_stats(): show block device statistics
*
* Each device statistic information is stored in a QDict and
* the returned QObject is a QList of all devices.
*
* The QDict contains the following:
*
* - "device": device name
* - "stats": A QDict with the statistics information, it contains:
* - "rd_bytes": bytes read
* - "wr_bytes": bytes written
* - "rd_operations": read operations
* - "wr_operations": write operations
*
* Example:
*
* [ { "device": "ide0-hd0",
* "stats": { "rd_bytes": 512,
* "wr_bytes": 0,
* "rd_operations": 1,
* "wr_operations": 0 } },
* { "device": "ide1-cd0",
* "stats": { "rd_bytes": 0,
* "wr_bytes": 0,
* "rd_operations": 0,
* "wr_operations": 0 } } ]
*/
void bdrv_info_stats(Monitor *mon, QObject **ret_data)
{
QObject *obj;
QList *devices;
BlockDriverState *bs;
devices = qlist_new();
for (bs = bdrv_first; bs != NULL; bs = bs->next) {
obj = qobject_from_jsonf("{ 'device': %s, 'stats': {"
"'rd_bytes': %" PRId64 ","
"'wr_bytes': %" PRId64 ","
"'rd_operations': %" PRId64 ","
"'wr_operations': %" PRId64
"} }",
bs->device_name,
bs->rd_bytes, bs->wr_bytes,
bs->rd_ops, bs->wr_ops);
assert(obj != NULL);
qlist_append_obj(devices, obj);
}
*ret_data = QOBJECT(devices);
}
const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
{
if (bs->backing_hd && bs->backing_hd->encrypted)
return bs->backing_file;
else if (bs->encrypted)
return bs->filename;
else
return NULL;
}
void bdrv_get_backing_filename(BlockDriverState *bs,
char *filename, int filename_size)
{
if (!bs->backing_file) {
pstrcpy(filename, filename_size, "");
} else {
pstrcpy(filename, filename_size, bs->backing_file);
}
}
int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_write_compressed)
return -ENOTSUP;
if (bdrv_check_request(bs, sector_num, nb_sectors))
return -EIO;
if (bs->dirty_bitmap) {
set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
}
return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
}
int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_get_info)
return -ENOTSUP;
memset(bdi, 0, sizeof(*bdi));
return drv->bdrv_get_info(bs, bdi);
}
int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
int64_t pos, int size)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_save_vmstate)
return -ENOTSUP;
return drv->bdrv_save_vmstate(bs, buf, pos, size);
}
int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
int64_t pos, int size)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_load_vmstate)
return -ENOTSUP;
return drv->bdrv_load_vmstate(bs, buf, pos, size);
}
/**************************************************************/
/* handling of snapshots */
int bdrv_snapshot_create(BlockDriverState *bs,
QEMUSnapshotInfo *sn_info)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_snapshot_create)
return -ENOTSUP;
return drv->bdrv_snapshot_create(bs, sn_info);
}
int bdrv_snapshot_goto(BlockDriverState *bs,
const char *snapshot_id)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_snapshot_goto)
return -ENOTSUP;
return drv->bdrv_snapshot_goto(bs, snapshot_id);
}
int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_snapshot_delete)
return -ENOTSUP;
return drv->bdrv_snapshot_delete(bs, snapshot_id);
}
int bdrv_snapshot_list(BlockDriverState *bs,
QEMUSnapshotInfo **psn_info)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_snapshot_list)
return -ENOTSUP;
return drv->bdrv_snapshot_list(bs, psn_info);
}
#define NB_SUFFIXES 4
char *get_human_readable_size(char *buf, int buf_size, int64_t size)
{
static const char suffixes[NB_SUFFIXES] = "KMGT";
int64_t base;
int i;
if (size <= 999) {
snprintf(buf, buf_size, "%" PRId64, size);
} else {
base = 1024;
for(i = 0; i < NB_SUFFIXES; i++) {
if (size < (10 * base)) {
snprintf(buf, buf_size, "%0.1f%c",
(double)size / base,
suffixes[i]);
break;
} else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
snprintf(buf, buf_size, "%" PRId64 "%c",
((size + (base >> 1)) / base),
suffixes[i]);
break;
}
base = base * 1024;
}
}
return buf;
}
char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
{
char buf1[128], date_buf[128], clock_buf[128];
#ifdef _WIN32
struct tm *ptm;
#else
struct tm tm;
#endif
time_t ti;
int64_t secs;
if (!sn) {
snprintf(buf, buf_size,
"%-10s%-20s%7s%20s%15s",
"ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
} else {
ti = sn->date_sec;
#ifdef _WIN32
ptm = localtime(&ti);
strftime(date_buf, sizeof(date_buf),
"%Y-%m-%d %H:%M:%S", ptm);
#else
localtime_r(&ti, &tm);
strftime(date_buf, sizeof(date_buf),
"%Y-%m-%d %H:%M:%S", &tm);
#endif
secs = sn->vm_clock_nsec / 1000000000;
snprintf(clock_buf, sizeof(clock_buf),
"%02d:%02d:%02d.%03d",
(int)(secs / 3600),
(int)((secs / 60) % 60),
(int)(secs % 60),
(int)((sn->vm_clock_nsec / 1000000) % 1000));
snprintf(buf, buf_size,
"%-10s%-20s%7s%20s%15s",
sn->id_str, sn->name,
get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
date_buf,
clock_buf);
}
return buf;
}
/**************************************************************/
/* async I/Os */
BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriver *drv = bs->drv;
BlockDriverAIOCB *ret;
if (!drv)
return NULL;
if (bdrv_check_request(bs, sector_num, nb_sectors))
return NULL;
ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
cb, opaque);
if (ret) {
/* Update stats even though technically transfer has not happened. */
bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
bs->rd_ops ++;
}
return ret;
}
BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriver *drv = bs->drv;
BlockDriverAIOCB *ret;
if (!drv)
return NULL;
if (bs->read_only)
return NULL;
if (bdrv_check_request(bs, sector_num, nb_sectors))
return NULL;
if (bs->dirty_bitmap) {
set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
}
ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
cb, opaque);
if (ret) {
/* Update stats even though technically transfer has not happened. */
bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
bs->wr_ops ++;
}
return ret;
}
typedef struct MultiwriteCB {
int error;
int num_requests;
int num_callbacks;
struct {
BlockDriverCompletionFunc *cb;
void *opaque;
QEMUIOVector *free_qiov;
void *free_buf;
} callbacks[];
} MultiwriteCB;
static void multiwrite_user_cb(MultiwriteCB *mcb)
{
int i;
for (i = 0; i < mcb->num_callbacks; i++) {
mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
qemu_free(mcb->callbacks[i].free_qiov);
qemu_vfree(mcb->callbacks[i].free_buf);
}
}
static void multiwrite_cb(void *opaque, int ret)
{
MultiwriteCB *mcb = opaque;
if (ret < 0) {
mcb->error = ret;
multiwrite_user_cb(mcb);
}
mcb->num_requests--;
if (mcb->num_requests == 0) {
if (mcb->error == 0) {
multiwrite_user_cb(mcb);
}
qemu_free(mcb);
}
}
static int multiwrite_req_compare(const void *a, const void *b)
{
return (((BlockRequest*) a)->sector - ((BlockRequest*) b)->sector);
}
/*
* Takes a bunch of requests and tries to merge them. Returns the number of
* requests that remain after merging.
*/
static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
int num_reqs, MultiwriteCB *mcb)
{
int i, outidx;
// Sort requests by start sector
qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
// Check if adjacent requests touch the same clusters. If so, combine them,
// filling up gaps with zero sectors.
outidx = 0;
for (i = 1; i < num_reqs; i++) {
int merge = 0;
int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
// This handles the cases that are valid for all block drivers, namely
// exactly sequential writes and overlapping writes.
if (reqs[i].sector <= oldreq_last) {
merge = 1;
}
// The block driver may decide that it makes sense to combine requests
// even if there is a gap of some sectors between them. In this case,
// the gap is filled with zeros (therefore only applicable for yet
// unused space in format like qcow2).
if (!merge && bs->drv->bdrv_merge_requests) {
merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
}
if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
merge = 0;
}
if (merge) {
size_t size;
QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
qemu_iovec_init(qiov,
reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
// Add the first request to the merged one. If the requests are
// overlapping, drop the last sectors of the first request.
size = (reqs[i].sector - reqs[outidx].sector) << 9;
qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
// We might need to add some zeros between the two requests
if (reqs[i].sector > oldreq_last) {
size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
uint8_t *buf = qemu_blockalign(bs, zero_bytes);
memset(buf, 0, zero_bytes);
qemu_iovec_add(qiov, buf, zero_bytes);
mcb->callbacks[i].free_buf = buf;
}
// Add the second request
qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
reqs[outidx].nb_sectors += reqs[i].nb_sectors;
reqs[outidx].qiov = qiov;
mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
} else {
outidx++;
reqs[outidx].sector = reqs[i].sector;
reqs[outidx].nb_sectors = reqs[i].nb_sectors;
reqs[outidx].qiov = reqs[i].qiov;
}
}
return outidx + 1;
}
/*
* Submit multiple AIO write requests at once.
*
* On success, the function returns 0 and all requests in the reqs array have
* been submitted. In error case this function returns -1, and any of the
* requests may or may not be submitted yet. In particular, this means that the
* callback will be called for some of the requests, for others it won't. The
* caller must check the error field of the BlockRequest to wait for the right
* callbacks (if error != 0, no callback will be called).
*
* The implementation may modify the contents of the reqs array, e.g. to merge
* requests. However, the fields opaque and error are left unmodified as they
* are used to signal failure for a single request to the caller.
*/
int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
{
BlockDriverAIOCB *acb;
MultiwriteCB *mcb;
int i;
if (num_reqs == 0) {
return 0;
}
// Create MultiwriteCB structure
mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
mcb->num_requests = 0;
mcb->num_callbacks = num_reqs;
for (i = 0; i < num_reqs; i++) {
mcb->callbacks[i].cb = reqs[i].cb;
mcb->callbacks[i].opaque = reqs[i].opaque;
}
// Check for mergable requests
num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
// Run the aio requests
for (i = 0; i < num_reqs; i++) {
acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
reqs[i].nb_sectors, multiwrite_cb, mcb);
if (acb == NULL) {
// We can only fail the whole thing if no request has been
// submitted yet. Otherwise we'll wait for the submitted AIOs to
// complete and report the error in the callback.
if (mcb->num_requests == 0) {
reqs[i].error = EIO;
goto fail;
} else {
mcb->error = EIO;
break;
}
} else {
mcb->num_requests++;
}
}
return 0;
fail:
free(mcb);
return -1;
}
BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriver *drv = bs->drv;
if (!drv)
return NULL;
return drv->bdrv_aio_flush(bs, cb, opaque);
}
void bdrv_aio_cancel(BlockDriverAIOCB *acb)
{
acb->pool->cancel(acb);
}
/**************************************************************/
/* async block device emulation */
typedef struct BlockDriverAIOCBSync {
BlockDriverAIOCB common;
QEMUBH *bh;
int ret;
/* vector translation state */
QEMUIOVector *qiov;
uint8_t *bounce;
int is_write;
} BlockDriverAIOCBSync;
static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
{
BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
qemu_bh_delete(acb->bh);
acb->bh = NULL;
qemu_aio_release(acb);
}
static AIOPool bdrv_em_aio_pool = {
.aiocb_size = sizeof(BlockDriverAIOCBSync),
.cancel = bdrv_aio_cancel_em,
};
static void bdrv_aio_bh_cb(void *opaque)
{
BlockDriverAIOCBSync *acb = opaque;
if (!acb->is_write)
qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
qemu_vfree(acb->bounce);
acb->common.cb(acb->common.opaque, acb->ret);
qemu_bh_delete(acb->bh);
acb->bh = NULL;
qemu_aio_release(acb);
}
static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
int64_t sector_num,
QEMUIOVector *qiov,
int nb_sectors,
BlockDriverCompletionFunc *cb,
void *opaque,
int is_write)
{
BlockDriverAIOCBSync *acb;
acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
acb->is_write = is_write;
acb->qiov = qiov;
acb->bounce = qemu_blockalign(bs, qiov->size);
if (!acb->bh)
acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
if (is_write) {
qemu_iovec_to_buffer(acb->qiov, acb->bounce);
acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
} else {
acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
}
qemu_bh_schedule(acb->bh);
return &acb->common;
}
static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
}
static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
}
static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriverAIOCBSync *acb;
acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
acb->is_write = 1; /* don't bounce in the completion hadler */
acb->qiov = NULL;
acb->bounce = NULL;
acb->ret = 0;
if (!acb->bh)
acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
bdrv_flush(bs);
qemu_bh_schedule(acb->bh);
return &acb->common;
}
/**************************************************************/
/* sync block device emulation */
static void bdrv_rw_em_cb(void *opaque, int ret)
{
*(int *)opaque = ret;
}
#define NOT_DONE 0x7fffffff
static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
int async_ret;
BlockDriverAIOCB *acb;
struct iovec iov;
QEMUIOVector qiov;
async_context_push();
async_ret = NOT_DONE;
iov.iov_base = (void *)buf;
iov.iov_len = nb_sectors * 512;
qemu_iovec_init_external(&qiov, &iov, 1);
acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
bdrv_rw_em_cb, &async_ret);
if (acb == NULL) {
async_ret = -1;
goto fail;
}
while (async_ret == NOT_DONE) {
qemu_aio_wait();
}
fail:
async_context_pop();
return async_ret;
}
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
int async_ret;
BlockDriverAIOCB *acb;
struct iovec iov;
QEMUIOVector qiov;
async_context_push();
async_ret = NOT_DONE;
iov.iov_base = (void *)buf;
iov.iov_len = nb_sectors * 512;
qemu_iovec_init_external(&qiov, &iov, 1);
acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
bdrv_rw_em_cb, &async_ret);
if (acb == NULL) {
async_ret = -1;
goto fail;
}
while (async_ret == NOT_DONE) {
qemu_aio_wait();
}
fail:
async_context_pop();
return async_ret;
}
void bdrv_init(void)
{
module_call_init(MODULE_INIT_BLOCK);
}
void bdrv_init_with_whitelist(void)
{
use_bdrv_whitelist = 1;
bdrv_init();
}
void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriverAIOCB *acb;
if (pool->free_aiocb) {
acb = pool->free_aiocb;
pool->free_aiocb = acb->next;
} else {
acb = qemu_mallocz(pool->aiocb_size);
acb->pool = pool;
}
acb->bs = bs;
acb->cb = cb;
acb->opaque = opaque;
return acb;
}
void qemu_aio_release(void *p)
{
BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
AIOPool *pool = acb->pool;
acb->next = pool->free_aiocb;
pool->free_aiocb = acb;
}
/**************************************************************/
/* removable device support */
/**
* Return TRUE if the media is present
*/
int bdrv_is_inserted(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
int ret;
if (!drv)
return 0;
if (!drv->bdrv_is_inserted)
return 1;
ret = drv->bdrv_is_inserted(bs);
return ret;
}
/**
* Return TRUE if the media changed since the last call to this
* function. It is currently only used for floppy disks
*/
int bdrv_media_changed(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
int ret;
if (!drv || !drv->bdrv_media_changed)
ret = -ENOTSUP;
else
ret = drv->bdrv_media_changed(bs);
if (ret == -ENOTSUP)
ret = bs->media_changed;
bs->media_changed = 0;
return ret;
}
/**
* If eject_flag is TRUE, eject the media. Otherwise, close the tray
*/
int bdrv_eject(BlockDriverState *bs, int eject_flag)
{
BlockDriver *drv = bs->drv;
int ret;
if (bs->locked) {
return -EBUSY;
}
if (!drv || !drv->bdrv_eject) {
ret = -ENOTSUP;
} else {
ret = drv->bdrv_eject(bs, eject_flag);
}
if (ret == -ENOTSUP) {
if (eject_flag)
bdrv_close(bs);
ret = 0;
}
return ret;
}
int bdrv_is_locked(BlockDriverState *bs)
{
return bs->locked;
}
/**
* Lock or unlock the media (if it is locked, the user won't be able
* to eject it manually).
*/
void bdrv_set_locked(BlockDriverState *bs, int locked)
{
BlockDriver *drv = bs->drv;
bs->locked = locked;
if (drv && drv->bdrv_set_locked) {
drv->bdrv_set_locked(bs, locked);
}
}
/* needed for generic scsi interface */
int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
{
BlockDriver *drv = bs->drv;
if (drv && drv->bdrv_ioctl)
return drv->bdrv_ioctl(bs, req, buf);
return -ENOTSUP;
}
BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
unsigned long int req, void *buf,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriver *drv = bs->drv;
if (drv && drv->bdrv_aio_ioctl)
return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
return NULL;
}
void *qemu_blockalign(BlockDriverState *bs, size_t size)
{
return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
}
void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
{
int64_t bitmap_size;
bs->dirty_count = 0;
if (enable) {
if (!bs->dirty_bitmap) {
bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
bs->dirty_bitmap = qemu_mallocz(bitmap_size);
}
} else {
if (bs->dirty_bitmap) {
qemu_free(bs->dirty_bitmap);
bs->dirty_bitmap = NULL;
}
}
}
int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
{
int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
if (bs->dirty_bitmap &&
(sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
return bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
(1 << (chunk % (sizeof(unsigned long) * 8)));
} else {
return 0;
}
}
void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
int nr_sectors)
{
set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
}
int64_t bdrv_get_dirty_count(BlockDriverState *bs)
{
return bs->dirty_count;
}
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