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[Qemu-devel] [RFC V2 17/20] qcow2: Integrate deduplication in qcow2_co_w
From: |
Benoît Canet |
Subject: |
[Qemu-devel] [RFC V2 17/20] qcow2: Integrate deduplication in qcow2_co_writev loop. |
Date: |
Wed, 17 Oct 2012 18:00:26 +0200 |
---
block/qcow2.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 78 insertions(+), 1 deletion(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index c6879ea..e0c1a68 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -330,6 +330,7 @@ static int qcow2_open(BlockDriverState *bs, int flags)
QCowHeader header;
uint64_t ext_end;
+ s->has_dedup = false;
ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
if (ret < 0) {
goto fail;
@@ -812,6 +813,12 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
QEMUIOVector hd_qiov;
uint64_t bytes_done = 0;
uint8_t *cluster_data = NULL;
+ uint8_t *dedup_cluster_data = NULL;
+ uint8_t *next_call_first_hash;
+ int dedup_cluster_data_nr;
+ int deduped_sectors_nr;
+ int skip_before_dedup_clusters_nr;
+ int next_non_dedupable_sectors_nr;
QCowL2Meta l2meta = {
.nb_clusters = 0,
};
@@ -827,11 +834,66 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
qemu_co_mutex_lock(&s->lock);
+ if (s->has_dedup) {
+ /* if deduplication is on we make sure dedup_cluster_data
+ * contains a multiple of cluster size of data in order
+ * to compute the hashes
+ */
+ ret = qcow2_dedup_read_missing_and_concatenate(bs,
+ qiov,
+ sector_num,
+ remaining_sectors,
+ &dedup_cluster_data,
+ &dedup_cluster_data_nr);
+
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+
+ next_call_first_hash = NULL;
+ next_non_dedupable_sectors_nr = 0;
+ skip_before_dedup_clusters_nr = 0;
while (remaining_sectors != 0) {
trace_qcow2_writev_start_part(qemu_coroutine_self());
+
+ if (s->has_dedup && next_non_dedupable_sectors_nr == 0) {
+ /* Try to deduplicate as much clusters as possible */
+ deduped_sectors_nr = qcow2_dedup(bs,
+ sector_num,
+ dedup_cluster_data,
+ dedup_cluster_data_nr,
+ &skip_before_dedup_clusters_nr,
+ &next_non_dedupable_sectors_nr,
+ &next_call_first_hash);
+
+ remaining_sectors -= deduped_sectors_nr;
+ sector_num += deduped_sectors_nr;
+ bytes_done += deduped_sectors_nr * 512;
+
+ /* no more data to write -> exit
+ * Can be < 0 because of the presence of sectors we read in
+ * qcow2_read_missing_dedup_sectors_and_concatenate.
+ */
+ if (next_non_dedupable_sectors_nr <= 0) {
+ goto fail;
+ }
+
+ /* if we deduped something trace it */
+ if (deduped_sectors_nr) {
+ trace_qcow2_writev_done_part(qemu_coroutine_self(),
+ deduped_sectors_nr);
+ trace_qcow2_writev_start_part(qemu_coroutine_self());
+ }
+ }
+
index_in_cluster = sector_num & (s->cluster_sectors - 1);
- n_end = index_in_cluster + remaining_sectors;
+ n_end = s->has_dedup &&
+ next_non_dedupable_sectors_nr < remaining_sectors ?
+ index_in_cluster + next_non_dedupable_sectors_nr :
+ index_in_cluster + remaining_sectors;
+
if (s->crypt_method &&
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) {
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
@@ -873,6 +935,19 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
cur_nr_sectors * 512);
}
+ /* Write the non duplicated clusters hashes to disk
+ * just before writing non duplicated data.
+ */
+ if (s->has_dedup) {
+ ret = qcow2_dedup_write_new_hashes(bs,
+ (cluster_offset >> 9),
+ cur_nr_sectors /
+ s->cluster_sectors);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
qemu_co_mutex_unlock(&s->lock);
trace_qcow2_writev_data(qemu_coroutine_self(),
@@ -892,6 +967,7 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
run_dependent_requests(s, &l2meta);
+ next_non_dedupable_sectors_nr -= cur_nr_sectors;
remaining_sectors -= cur_nr_sectors;
sector_num += cur_nr_sectors;
bytes_done += cur_nr_sectors * 512;
@@ -906,6 +982,7 @@ fail:
qemu_iovec_destroy(&hd_qiov);
qemu_vfree(cluster_data);
+ qemu_vfree(dedup_cluster_data);
trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
return ret;
--
1.7.10.4
- [Qemu-devel] [RFC V2 06/20] qcow2: Add qcow2_dedup and related functions., (continued)
- [Qemu-devel] [RFC V2 06/20] qcow2: Add qcow2_dedup and related functions., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 07/20] qcow2: Add qcow2_dedup_write_new_hashes., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 08/20] qcow2: Implement qcow2_compute_cluster_hash., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 09/20] qcow2: Add qcow2_co_load_dedup_hashes., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 05/20] qcow2: Rename update_refcount into qcow2_update_refcount., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 04/20] qcow2: Add qcow2_de dup_read_missing_and_concatenate, Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 15/20] block: Add dedup image create option., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 01/20] qcow2: Add deduplication to the qcow2 specification., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 17/20] qcow2: Integrate deduplication in qcow2_co_writev loop.,
Benoît Canet <=
- [Qemu-devel] [RFC V2 16/20] qcow2: Allow creation of images using deduplication., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 10/20] qcow2: Add qcow2_dedup_grow_table., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 12/20] qcow2: Extract qcow2_do_table_init., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 20/20] qemu-iotests: Filter dedup=on/off so existing tests don't break., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 13/20] qcow2: Add qcow2_dedup_init and qcow2_dedup_close., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 18/20] qcow2: Add method to destroy the deduplication red black tree., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 19/20] qcow2: init and cleanup deduplication., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 02/20] qcow2: Add kernel red black trees, Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 11/20] qcow2: Load and save deduplication table header extension., Benoît Canet, 2012/10/17
- [Qemu-devel] [RFC V2 14/20] qcow2: Extract qcow2_add_feature and qcow2_remove_feature., Benoît Canet, 2012/10/17