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[Qemu-devel] [PATCH v6 04/16] qcow2: add qcow2_co_pwritev_compressed
From: |
Denis V. Lunev |
Subject: |
[Qemu-devel] [PATCH v6 04/16] qcow2: add qcow2_co_pwritev_compressed |
Date: |
Thu, 21 Jul 2016 22:40:07 +0300 |
From: Pavel Butsykin <address@hidden>
Added implementation of the qcow2_co_pwritev_compressed function that
will allow us to safely use compressed writes for the qcow2 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>
---
block/qcow2.c | 124 +++++++++++++++++++++++-----------------------------------
1 file changed, 50 insertions(+), 74 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index d620d0a..b5c69df 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2533,84 +2533,49 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t
offset)
return 0;
}
-typedef struct Qcow2WriteCo {
- BlockDriverState *bs;
- int64_t sector_num;
- const uint8_t *buf;
- int nb_sectors;
- int ret;
-} Qcow2WriteCo;
-
-static void qcow2_write_co_entry(void *opaque)
-{
- Qcow2WriteCo *co = opaque;
- QEMUIOVector qiov;
- uint64_t offset = co->sector_num * BDRV_SECTOR_SIZE;
- uint64_t bytes = co->nb_sectors * BDRV_SECTOR_SIZE;
-
- struct iovec iov = (struct iovec) {
- .iov_base = (uint8_t*) co->buf,
- .iov_len = bytes,
- };
- qemu_iovec_init_external(&qiov, &iov, 1);
-
- co->ret = qcow2_co_pwritev(co->bs, offset, bytes, &qiov, 0);
-}
-
-/* Wrapper for non-coroutine contexts */
-static int qcow2_write(BlockDriverState *bs, int64_t sector_num,
- const uint8_t *buf, int nb_sectors)
-{
- Coroutine *co;
- AioContext *aio_context = bdrv_get_aio_context(bs);
- Qcow2WriteCo data = {
- .bs = bs,
- .sector_num = sector_num,
- .buf = buf,
- .nb_sectors = nb_sectors,
- .ret = -EINPROGRESS,
- };
- co = qemu_coroutine_create(qcow2_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 qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num,
- const uint8_t *buf, int nb_sectors)
+static coroutine_fn int
+qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
+ uint64_t bytes, QEMUIOVector *qiov)
{
BDRVQcow2State *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 == 0) {
+ if (bytes == 0) {
/* align end of file to a sector boundary to ease reading with
sector based I/Os */
cluster_offset = bdrv_getlength(bs->file->bs);
return bdrv_truncate(bs->file->bs, 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 = qcow2_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 = qcow2_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, s->cluster_size);
out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
@@ -2641,33 +2606,44 @@ static int qcow2_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 = qcow2_write(bs, sector_num, buf, s->cluster_sectors);
+ ret = qcow2_co_pwritev(bs, offset, bytes, qiov, 0);
if (ret < 0) {
goto fail;
}
- } else {
- cluster_offset = qcow2_alloc_compressed_cluster_offset(bs,
- sector_num << 9, out_len);
- if (!cluster_offset) {
- ret = -EIO;
- goto fail;
- }
- cluster_offset &= s->cluster_offset_mask;
+ goto success;
+ }
- ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len);
- if (ret < 0) {
- goto fail;
- }
+ qemu_co_mutex_lock(&s->lock);
+ cluster_offset =
+ qcow2_alloc_compressed_cluster_offset(bs, offset, out_len);
+ if (!cluster_offset) {
+ qemu_co_mutex_unlock(&s->lock);
+ ret = -EIO;
+ goto fail;
+ }
+ cluster_offset &= s->cluster_offset_mask;
- BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
- ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len);
- if (ret < 0) {
- goto fail;
- }
+ ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len);
+ qemu_co_mutex_unlock(&s->lock);
+ if (ret < 0) {
+ goto fail;
}
+ iov = (struct iovec) {
+ .iov_base = out_buf,
+ .iov_len = out_len,
+ };
+ qemu_iovec_init_external(&hd_qiov, &iov, 1);
+
+ BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
+ 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;
}
@@ -3412,7 +3388,7 @@ BlockDriver bdrv_qcow2 = {
.bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes,
.bdrv_co_pdiscard = qcow2_co_pdiscard,
.bdrv_truncate = qcow2_truncate,
- .bdrv_write_compressed = qcow2_write_compressed,
+ .bdrv_co_pwritev_compressed = qcow2_co_pwritev_compressed,
.bdrv_make_empty = qcow2_make_empty,
.bdrv_snapshot_create = qcow2_snapshot_create,
--
2.5.0
- [Qemu-devel] [PATCH v6 00/16] backup compression, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 10/16] block/io: turn on dirty_bitmaps for the compressed writes, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 06/16] vmdk: add vmdk_co_pwritev_compressed, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 11/16] block: simplify drive-backup, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 04/16] qcow2: add qcow2_co_pwritev_compressed,
Denis V. Lunev <=
- [Qemu-devel] [PATCH v6 08/16] qcow: cleanup qcow_co_pwritev_compressed to avoid the recursion, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 03/16] block/io: reuse bdrv_co_pwritev() for write compressed, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 16/16] qemu-iotests: add vmdk for test backup compression in 055, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 05/16] qcow2: cleanup qcow2_co_pwritev_compressed to avoid the recursion, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 09/16] block: remove BlockDriver.bdrv_write_compressed, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 12/16] block: simplify blockdev-backup, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 15/16] qemu-iotests: test backup compression in 055, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 13/16] drive-backup: added support for data compression, Denis V. Lunev, 2016/07/21
- [Qemu-devel] [PATCH v6 01/16] block: switch blk_write_compressed() to byte-based interface, Denis V. Lunev, 2016/07/21