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[Qemu-devel] [RFC V3 18/24] qcow2: Integrate deduplication in qcow2_co_w
From: |
Benoît Canet |
Subject: |
[Qemu-devel] [RFC V3 18/24] qcow2: Integrate deduplication in qcow2_co_writev loop. |
Date: |
Mon, 26 Nov 2012 14:05:17 +0100 |
Signed-off-by: Benoit Canet <address@hidden>
---
block/qcow2.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 85 insertions(+), 1 deletion(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index e641049..d5f28dd 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;
@@ -812,11 +813,19 @@ 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;
+ UndedupableHashes u;
QCowL2Meta l2meta = {
.nb_clusters = 0,
.oflag_copied = true,
.overwrite = false,
};
+ QTAILQ_INIT(&u.undedupable_hashes);
trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num,
remaining_sectors);
@@ -829,11 +838,67 @@ 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,
+ &u,
+ 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;
@@ -875,6 +940,23 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
cur_nr_sectors * 512);
}
+ /* Write the non duplicated clusters hashes to disk */
+ if (s->has_dedup) {
+ int count = cur_nr_sectors / s->cluster_sectors;
+ int has_ending = ((cluster_offset >> 9) + index_in_cluster +
+ cur_nr_sectors) & (s->cluster_sectors - 1);
+ count = index_in_cluster ? count + 1 : count;
+ count = has_ending ? count + 1 : count;
+ ret = qcow2_dedup_write_new_hashes(bs,
+ &u,
+ count,
+ sector_num,
+ (cluster_offset >> 9));
+ 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(),
@@ -894,6 +976,7 @@ 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;
@@ -908,6 +991,7 @@ 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 V3 12/24] qcow2: Extract qcow2_do_table_init., (continued)
- [Qemu-devel] [RFC V3 12/24] qcow2: Extract qcow2_do_table_init., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 11/24] qcow2: Load and save deduplication table header extension., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 14/24] qcow2: Extract qcow2_add_feature and qcow2_remove_feature., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 16/24] qcow2: Allow creation of images using deduplication., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 17/24] qcow2: Behave correctly when refcount reach 0 or 2^16., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 19/24] qcow2: Add verification of dedup table., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 24/24] qemu-iotests: Filter dedup=on/off so existing tests don't break., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 20/24] qcow2: Adapt checking of QCOW_OFLAG_COPIED for dedup., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 22/24] qcow2: Do not overwrite existing entries with QCOW_OFLAG_COPIED., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 07/24] qcow2: Add qcow2_dedup_write_new_hashes., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 18/24] qcow2: Integrate deduplication in qcow2_co_writev loop.,
Benoît Canet <=
- [Qemu-devel] [RFC V3 08/24] qcow2: Implement qcow2_compute_cluster_hash., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 21/24] qcow2: Add check_dedup_l2 in order to check l2 of dedup table., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 23/24] qcow2: init and cleanup deduplication., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 10/24] qcow2: create function to load deduplication hashes at startup., Benoît Canet, 2012/11/26
- [Qemu-devel] [RFC V3 15/24] block: Add dedup image create option., Benoît Canet, 2012/11/26