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block/parallels: _co_writev callback for Parallels format

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Support write on Parallels images. The code is almost the same as one
in the previous patch implemented scatter-gather IO for read.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Roman Kagan <rkagan@parallels.com>
Signed-off-by: Roman Kagan <rkagan@parallels.com>
Message-id: 1430207220-24458-10-git-send-email-den@openvz.org
CC: Roman Kagan <rkagan@parallels.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Denis V. Lunev 2015-04-28 10:46:42 +03:00 committed by Stefan Hajnoczi
parent d0e61ce56d
commit 5a41e1fa95
1 changed files with 88 additions and 2 deletions
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90
block/parallels.c
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@ -60,6 +60,8 @@ typedef struct BDRVParallelsState {
unsigned int tracks;
unsigned int off_multiplier;
bool has_truncate;
} BDRVParallelsState;
static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename)
@ -85,8 +87,6 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
ParallelsHeader ph;
int ret;
bs->read_only = 1; // no write support yet
ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
if (ret < 0) {
goto fail;
@ -139,6 +139,9 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
for (i = 0; i < s->catalog_size; i++)
le32_to_cpus(&s->catalog_bitmap[i]);
s->has_truncate = bdrv_has_zero_init(bs->file) &&
bdrv_truncate(bs->file, bdrv_getlength(bs->file)) == 0;
qemu_co_mutex_init(&s->lock);
return 0;
@ -170,6 +173,46 @@ static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
return MIN(nb_sectors, ret);
}
static int64_t allocate_cluster(BlockDriverState *bs, int64_t sector_num)
{
BDRVParallelsState *s = bs->opaque;
uint32_t idx, offset, tmp;
int64_t pos;
int ret;
idx = sector_num / s->tracks;
offset = sector_num % s->tracks;
if (idx >= s->catalog_size) {
return -EINVAL;
}
if (s->catalog_bitmap[idx] != 0) {
return (uint64_t)s->catalog_bitmap[idx] * s->off_multiplier + offset;
}
pos = bdrv_getlength(bs->file) >> BDRV_SECTOR_BITS;
if (s->has_truncate) {
ret = bdrv_truncate(bs->file, (pos + s->tracks) << BDRV_SECTOR_BITS);
} else {
ret = bdrv_write_zeroes(bs->file, pos, s->tracks, 0);
}
if (ret < 0) {
return ret;
}
s->catalog_bitmap[idx] = pos / s->off_multiplier;
tmp = cpu_to_le32(s->catalog_bitmap[idx]);
ret = bdrv_pwrite(bs->file,
sizeof(ParallelsHeader) + idx * sizeof(tmp), &tmp, sizeof(tmp));
if (ret < 0) {
s->catalog_bitmap[idx] = 0;
return ret;
}
return (uint64_t)s->catalog_bitmap[idx] * s->off_multiplier + offset;
}
static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, int *pnum)
{
@ -190,6 +233,48 @@ static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
}
static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
BDRVParallelsState *s = bs->opaque;
uint64_t bytes_done = 0;
QEMUIOVector hd_qiov;
int ret = 0;
qemu_iovec_init(&hd_qiov, qiov->niov);
while (nb_sectors > 0) {
int64_t position;
int n, nbytes;
qemu_co_mutex_lock(&s->lock);
position = allocate_cluster(bs, sector_num);
qemu_co_mutex_unlock(&s->lock);
if (position < 0) {
ret = (int)position;
break;
}
n = cluster_remainder(s, sector_num, nb_sectors);
nbytes = n << BDRV_SECTOR_BITS;
qemu_iovec_reset(&hd_qiov);
qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
ret = bdrv_co_writev(bs->file, position, n, &hd_qiov);
if (ret < 0) {
break;
}
nb_sectors -= n;
sector_num += n;
bytes_done += nbytes;
}
qemu_iovec_destroy(&hd_qiov);
return ret;
}
static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
@ -247,6 +332,7 @@ static BlockDriver bdrv_parallels = {
.bdrv_co_get_block_status = parallels_co_get_block_status,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_readv = parallels_co_readv,
.bdrv_co_writev = parallels_co_writev,
};
static void bdrv_parallels_init(void)