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[Qemu-block] [PULL 20/42] qcow: add qcow_co_pwritev_compressed
From: |
Kevin Wolf |
Subject: |
[Qemu-block] [PULL 20/42] qcow: add qcow_co_pwritev_compressed |
Date: |
Mon, 5 Sep 2016 20:13:32 +0200 |
From: Pavel Butsykin <address@hidden>
Added implementation of the qcow_co_pwritev_compressed function that
will allow us to safely use compressed writes for the qcow from running
VMs.
Signed-off-by: Pavel Butsykin <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Denis V. Lunev <address@hidden>
CC: Jeff Cody <address@hidden>
CC: Markus Armbruster <address@hidden>
CC: Eric Blake <address@hidden>
CC: John Snow <address@hidden>
CC: Stefan Hajnoczi <address@hidden>
CC: Kevin Wolf <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow.c | 109 +++++++++++++++++++++++------------------------------------
1 file changed, 42 insertions(+), 67 deletions(-)
diff --git a/block/qcow.c b/block/qcow.c
index 6f9b2e2..1b9c911 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -913,75 +913,42 @@ static int qcow_make_empty(BlockDriverState *bs)
return 0;
}
-typedef struct QcowWriteCo {
- BlockDriverState *bs;
- int64_t sector_num;
- const uint8_t *buf;
- int nb_sectors;
- int ret;
-} QcowWriteCo;
-
-static void qcow_write_co_entry(void *opaque)
-{
- QcowWriteCo *co = opaque;
- QEMUIOVector qiov;
-
- struct iovec iov = (struct iovec) {
- .iov_base = (uint8_t*) co->buf,
- .iov_len = co->nb_sectors * BDRV_SECTOR_SIZE,
- };
- qemu_iovec_init_external(&qiov, &iov, 1);
-
- co->ret = qcow_co_writev(co->bs, co->sector_num, co->nb_sectors, &qiov);
-}
-
-/* Wrapper for non-coroutine contexts */
-static int qcow_write(BlockDriverState *bs, int64_t sector_num,
- const uint8_t *buf, int nb_sectors)
-{
- Coroutine *co;
- AioContext *aio_context = bdrv_get_aio_context(bs);
- QcowWriteCo data = {
- .bs = bs,
- .sector_num = sector_num,
- .buf = buf,
- .nb_sectors = nb_sectors,
- .ret = -EINPROGRESS,
- };
- co = qemu_coroutine_create(qcow_write_co_entry, &data);
- qemu_coroutine_enter(co);
- while (data.ret == -EINPROGRESS) {
- aio_poll(aio_context, true);
- }
- return data.ret;
-}
-
/* XXX: put compressed sectors first, then all the cluster aligned
tables to avoid losing bytes in alignment */
-static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
- const uint8_t *buf, int nb_sectors)
+static coroutine_fn int
+qcow_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
+ uint64_t bytes, QEMUIOVector *qiov)
{
BDRVQcowState *s = bs->opaque;
+ QEMUIOVector hd_qiov;
+ struct iovec iov;
z_stream strm;
int ret, out_len;
- uint8_t *out_buf;
+ uint8_t *buf, *out_buf;
uint64_t cluster_offset;
- if (nb_sectors != s->cluster_sectors) {
+ if (bytes != s->cluster_size) {
ret = -EINVAL;
/* Zero-pad last write if image size is not cluster aligned */
- if (sector_num + nb_sectors == bs->total_sectors &&
- nb_sectors < s->cluster_sectors) {
+ if (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS &&
+ bytes < s->cluster_size)
+ {
uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size);
memset(pad_buf, 0, s->cluster_size);
- memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE);
- ret = qcow_write_compressed(bs, sector_num,
- pad_buf, s->cluster_sectors);
+ qemu_iovec_to_buf(qiov, 0, pad_buf, s->cluster_size);
+ iov = (struct iovec) {
+ .iov_base = pad_buf,
+ .iov_len = s->cluster_size,
+ };
+ qemu_iovec_init_external(&hd_qiov, &iov, 1);
+ ret = qcow_co_pwritev_compressed(bs, offset, bytes, &hd_qiov);
qemu_vfree(pad_buf);
}
return ret;
}
+ buf = qemu_blockalign(bs, s->cluster_size);
+ qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
out_buf = g_malloc(s->cluster_size);
@@ -1012,27 +979,35 @@ static int qcow_write_compressed(BlockDriverState *bs,
int64_t sector_num,
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
/* could not compress: write normal cluster */
- ret = qcow_write(bs, sector_num, buf, s->cluster_sectors);
- if (ret < 0) {
- goto fail;
- }
- } else {
- cluster_offset = get_cluster_offset(bs, sector_num << 9, 2,
- out_len, 0, 0);
- if (cluster_offset == 0) {
- ret = -EIO;
- goto fail;
- }
-
- cluster_offset &= s->cluster_offset_mask;
- ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len);
+ ret = qcow_co_writev(bs, offset >> BDRV_SECTOR_BITS,
+ bytes >> BDRV_SECTOR_BITS, qiov);
if (ret < 0) {
goto fail;
}
+ goto success;
+ }
+ qemu_co_mutex_lock(&s->lock);
+ cluster_offset = get_cluster_offset(bs, offset, 2, out_len, 0, 0);
+ qemu_co_mutex_unlock(&s->lock);
+ if (cluster_offset == 0) {
+ ret = -EIO;
+ goto fail;
}
+ cluster_offset &= s->cluster_offset_mask;
+ iov = (struct iovec) {
+ .iov_base = out_buf,
+ .iov_len = out_len,
+ };
+ qemu_iovec_init_external(&hd_qiov, &iov, 1);
+ ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+success:
ret = 0;
fail:
+ qemu_vfree(buf);
g_free(out_buf);
return ret;
}
@@ -1085,7 +1060,7 @@ static BlockDriver bdrv_qcow = {
.bdrv_set_key = qcow_set_key,
.bdrv_make_empty = qcow_make_empty,
- .bdrv_write_compressed = qcow_write_compressed,
+ .bdrv_co_pwritev_compressed = qcow_co_pwritev_compressed,
.bdrv_get_info = qcow_get_info,
.create_opts = &qcow_create_opts,
--
1.8.3.1
- [Qemu-block] [PULL 10/42] block: Accept node-name for drive-backup, (continued)
- [Qemu-block] [PULL 10/42] block: Accept node-name for drive-backup, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 14/42] block: switch blk_write_compressed() to byte-based interface, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 16/42] block/io: reuse bdrv_co_pwritev() for write compressed, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 15/42] block: Convert bdrv_pwrite_compressed() to BdrvChild, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 19/42] vmdk: add vmdk_co_pwritev_compressed, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 11/42] block: Accept node-name for drive-mirror, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 13/42] nbd-server: Allow node name for nbd-server-add, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 17/42] qcow2: add qcow2_co_pwritev_compressed, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 18/42] qcow2: cleanup qcow2_co_pwritev_compressed to avoid the recursion, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 21/42] qcow: cleanup qcow_co_pwritev_compressed to avoid the recursion, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 20/42] qcow: add qcow_co_pwritev_compressed,
Kevin Wolf <=
- [Qemu-block] [PULL 22/42] block: remove BlockDriver.bdrv_write_compressed, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 28/42] qemu-iotests: test backup compression in 055, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 23/42] block/io: turn on dirty_bitmaps for the compressed writes, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 24/42] block: simplify drive-backup, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 25/42] block: simplify blockdev-backup, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 29/42] qemu-iotests: add vmdk for test backup compression in 055, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 26/42] drive-backup: added support for data compression, Kevin Wolf, 2016/09/05
- [Qemu-block] [PULL 27/42] blockdev-backup: added support for data compression, Kevin Wolf, 2016/09/05