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[Qemu-devel] [PULL 12/41] qcow2: aio support for compressed cluster read
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 12/41] qcow2: aio support for compressed cluster read |
Date: |
Wed, 12 Dec 2018 14:27:06 +0100 |
From: Vladimir Sementsov-Ogievskiy <address@hidden>
Allocate buffers locally and release qcow2 lock. Than, reads inside
qcow2_co_preadv_compressed may be done in parallel, however all
decompression is still done synchronously. Let's improve it in the
following commit.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
Reviewed-by: Alberto Garcia <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2.h | 4 ---
block/qcow2.c | 96 ++++++++++++++++++++++++++-------------------------
2 files changed, 49 insertions(+), 51 deletions(-)
diff --git a/block/qcow2.h b/block/qcow2.h
index 8662b68575..a98d24500b 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -278,9 +278,6 @@ typedef struct BDRVQcow2State {
QEMUTimer *cache_clean_timer;
unsigned cache_clean_interval;
- uint8_t *cluster_cache;
- uint8_t *cluster_data;
- uint64_t cluster_cache_offset;
QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
uint64_t *refcount_table;
@@ -616,7 +613,6 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t
min_size,
bool exact_size);
int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
-int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
uint8_t *buf, int nb_sectors, bool enc, Error
**errp);
diff --git a/block/qcow2.c b/block/qcow2.c
index d4b25d88b5..c1886c46e3 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -74,6 +74,13 @@ typedef struct {
#define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
#define QCOW2_EXT_MAGIC_BITMAPS 0x23852875
+static int coroutine_fn
+qcow2_co_preadv_compressed(BlockDriverState *bs,
+ uint64_t file_cluster_offset,
+ uint64_t offset,
+ uint64_t bytes,
+ QEMUIOVector *qiov);
+
static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
{
const QCowHeader *cow_header = (const void *)buf;
@@ -1414,7 +1421,6 @@ static int coroutine_fn qcow2_do_open(BlockDriverState
*bs, QDict *options,
goto fail;
}
- s->cluster_cache_offset = -1;
s->flags = flags;
ret = qcow2_refcount_init(bs);
@@ -1914,15 +1920,15 @@ static coroutine_fn int
qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
break;
case QCOW2_CLUSTER_COMPRESSED:
- /* add AIO support for compressed blocks ? */
- ret = qcow2_decompress_cluster(bs, cluster_offset);
+ qemu_co_mutex_unlock(&s->lock);
+ ret = qcow2_co_preadv_compressed(bs, cluster_offset,
+ offset, cur_bytes,
+ &hd_qiov);
+ qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
goto fail;
}
- qemu_iovec_from_buf(&hd_qiov, 0,
- s->cluster_cache + offset_in_cluster,
- cur_bytes);
break;
case QCOW2_CLUSTER_NORMAL:
@@ -2058,8 +2064,6 @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState
*bs, uint64_t offset,
qemu_iovec_init(&hd_qiov, qiov->niov);
- s->cluster_cache_offset = -1; /* disable compressed cache */
-
qemu_co_mutex_lock(&s->lock);
while (bytes != 0) {
@@ -2223,8 +2227,6 @@ static void qcow2_close(BlockDriverState *bs)
g_free(s->image_backing_file);
g_free(s->image_backing_format);
- g_free(s->cluster_cache);
- qemu_vfree(s->cluster_data);
qcow2_refcount_close(bs);
qcow2_free_snapshots(bs);
}
@@ -3401,7 +3403,6 @@ qcow2_co_copy_range_to(BlockDriverState *bs,
QCowL2Meta *l2meta = NULL;
assert(!bs->encrypted);
- s->cluster_cache_offset = -1; /* disable compressed cache */
qemu_co_mutex_lock(&s->lock);
@@ -3957,52 +3958,53 @@ fail:
return ret;
}
-int coroutine_fn
-qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
+static int coroutine_fn
+qcow2_co_preadv_compressed(BlockDriverState *bs,
+ uint64_t file_cluster_offset,
+ uint64_t offset,
+ uint64_t bytes,
+ QEMUIOVector *qiov)
{
BDRVQcow2State *s = bs->opaque;
- int ret, csize, nb_csectors;
+ int ret = 0, csize, nb_csectors;
uint64_t coffset;
+ uint8_t *buf, *out_buf;
struct iovec iov;
QEMUIOVector local_qiov;
+ int offset_in_cluster = offset_into_cluster(s, offset);
- coffset = cluster_offset & s->cluster_offset_mask;
- if (s->cluster_cache_offset != coffset) {
- nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
- csize = nb_csectors * 512 - (coffset & 511);
+ coffset = file_cluster_offset & s->cluster_offset_mask;
+ nb_csectors = ((file_cluster_offset >> s->csize_shift) & s->csize_mask) +
1;
+ csize = nb_csectors * 512 - (coffset & 511);
- /* Allocate buffers on first decompress operation, most images are
- * uncompressed and the memory overhead can be avoided. The buffers
- * are freed in .bdrv_close().
- */
- if (!s->cluster_data) {
- /* one more sector for decompressed data alignment */
- s->cluster_data = qemu_try_blockalign(bs->file->bs,
- QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size + 512);
- if (!s->cluster_data) {
- return -ENOMEM;
- }
- }
- if (!s->cluster_cache) {
- s->cluster_cache = g_malloc(s->cluster_size);
- }
+ buf = g_try_malloc(csize);
+ if (!buf) {
+ return -ENOMEM;
+ }
+ iov.iov_base = buf;
+ iov.iov_len = csize;
+ qemu_iovec_init_external(&local_qiov, &iov, 1);
- iov.iov_base = s->cluster_data;
- iov.iov_len = csize;
- qemu_iovec_init_external(&local_qiov, &iov, 1);
+ out_buf = qemu_blockalign(bs, s->cluster_size);
- BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
- ret = bdrv_co_preadv(bs->file, coffset, csize, &local_qiov, 0);
- if (ret < 0) {
- return ret;
- }
- if (qcow2_decompress(s->cluster_cache, s->cluster_size,
- s->cluster_data, csize) < 0) {
- return -EIO;
- }
- s->cluster_cache_offset = coffset;
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
+ ret = bdrv_co_preadv(bs->file, coffset, csize, &local_qiov, 0);
+ if (ret < 0) {
+ goto fail;
}
- return 0;
+
+ if (qcow2_decompress(out_buf, s->cluster_size, buf, csize) < 0) {
+ ret = -EIO;
+ goto fail;
+ }
+
+ qemu_iovec_from_buf(qiov, 0, out_buf + offset_in_cluster, bytes);
+
+fail:
+ qemu_vfree(out_buf);
+ g_free(buf);
+
+ return ret;
}
static int make_completely_empty(BlockDriverState *bs)
--
2.19.2
- [Qemu-devel] [PULL 03/41] dmg: including dmg-lzfse module inside dmg block driver., (continued)
- [Qemu-devel] [PULL 03/41] dmg: including dmg-lzfse module inside dmg block driver., Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 05/41] block/replication: drop extra synchronization, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 04/41] dmg: exchanging hardcoded dmg UDIF block types to enum., Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 09/41] qcow2: move decompression from qcow2-cluster.c to qcow2.c, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 06/41] block/backup: drop unused synchronization interface, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 08/41] qcow2: make more generic interface for qcow2_compress, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 10/41] qcow2: refactor decompress_buffer, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 11/41] qcow2: use byte-based read in qcow2_decompress_cluster, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 07/41] qcow2: use Z_OK instead of 0 for deflateInit2 return code check, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 13/41] qcow2: do decompression in threads, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 12/41] qcow2: aio support for compressed cluster read,
Kevin Wolf <=
- [Qemu-devel] [PULL 16/41] file-posix: Avoid aio_worker() for QEMU_AIO_TRUNCATE, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 14/41] file-posix: Reorganise RawPosixAIOData, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 15/41] file-posix: Factor out raw_thread_pool_submit(), Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 18/41] file-posix: Avoid aio_worker() for QEMU_AIO_WRITE_ZEROES, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 17/41] file-posix: Avoid aio_worker() for QEMU_AIO_COPY_RANGE, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 21/41] file-posix: Move read/write operation logic out of aio_worker(), Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 19/41] file-posix: Avoid aio_worker() for QEMU_AIO_DISCARD, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 20/41] file-posix: Avoid aio_worker() for QEMU_AIO_FLUSH, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 23/41] file-posix: Remove paio_submit_co(), Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 25/41] file-posix: Avoid aio_worker() for QEMU_AIO_IOCTL, Kevin Wolf, 2018/12/12