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 <d...@openvz.org>
Acked-by: Roman Kagan <rka...@parallels.com>
CC: Kevin Wolf <kw...@redhat.com>
CC: Stefan Hajnoczi <stefa...@redhat.com>
---
block/parallels.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 75 insertions(+), 2 deletions(-)
diff --git a/block/parallels.c b/block/parallels.c
index 306f2e3..dca3d0b 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -81,8 +81,6 @@ 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;
@@ -159,6 +157,37 @@ static int64_t seek_to_sector(BDRVParallelsState *s,
int64_t sector_num)
return (uint64_t)s->catalog_bitmap[index] * s->off_multiplier + offset;
}
+static int64_t allocate_sector(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;
+ bdrv_truncate(bs->file, (pos + s->tracks) << BDRV_SECTOR_BITS);
+ s->catalog_bitmap[idx] = pos / s->off_multiplier;
+
+ tmp = cpu_to_le32(s->catalog_bitmap[idx]);
+
+ ret = bdrv_pwrite_sync(bs->file,
+ sizeof(ParallelsHeader) + idx * sizeof(tmp), &tmp, sizeof(tmp));
+ if (ret < 0) {
+ return ret;
+ }
+ return (uint64_t)s->catalog_bitmap[idx] * s->off_multiplier + offset;
+}
+
static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
int nb_sectors)
{
@@ -186,6 +215,49 @@ 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);
+
+ qemu_co_mutex_lock(&s->lock);
+ while (nb_sectors > 0) {
+ int64_t position = allocate_sector(bs, sector_num);
+ int n = cluster_remainder(s, sector_num, nb_sectors);
+ int nbytes = n << BDRV_SECTOR_BITS;
+
+ if (position < 0) {
+ ret = (int)position;
+ break;
+ }
+
+ qemu_iovec_reset(&hd_qiov);
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
+
+ qemu_co_mutex_unlock(&s->lock);
+ ret = bdrv_co_writev(bs->file, position, n, &hd_qiov);
+ qemu_co_mutex_lock(&s->lock);
+
+ if (ret < 0) {
+ goto fail;
+ }
+
+ nb_sectors -= n;
+ sector_num += n;
+ bytes_done += nbytes;
+ }
+ qemu_co_mutex_unlock(&s->lock);
+
+fail:
+ 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)
{
@@ -242,6 +314,7 @@ static BlockDriver bdrv_parallels = {
.bdrv_close = parallels_close,
.bdrv_co_get_block_status = parallels_co_get_block_status,
.bdrv_co_readv = parallels_co_readv,
+ .bdrv_co_writev = parallels_co_writev,
};
static void bdrv_parallels_init(void)
--
1.9.1
