From: John Snow <js...@redhat.com>
64K might not always be appropriate, make this a runtime value.
Signed-off-by: John Snow <js...@redhat.com>
Reviewed-by: Fam Zheng <f...@redhat.com>
Message-id: 1456433911-24718-2-git-send-email-js...@redhat.com
Signed-off-by: Jeff Cody <jc...@redhat.com>
---
block/backup.c | 64 +++++++++++++++++++++++++++++++++-------------------------
1 file changed, 36 insertions(+), 28 deletions(-)
diff --git a/block/backup.c b/block/backup.c
index 00cafdb..76addef 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -21,10 +21,7 @@
#include "qemu/ratelimit.h"
#include "sysemu/block-backend.h"
-#define BACKUP_CLUSTER_BITS 16
-#define BACKUP_CLUSTER_SIZE (1 << BACKUP_CLUSTER_BITS)
-#define BACKUP_SECTORS_PER_CLUSTER (BACKUP_CLUSTER_SIZE / BDRV_SECTOR_SIZE)
-
+#define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
#define SLICE_TIME 100000000ULL /* ns */
typedef struct CowRequest {
@@ -46,9 +43,16 @@ typedef struct BackupBlockJob {
CoRwlock flush_rwlock;
uint64_t sectors_read;
HBitmap *bitmap;
+ int64_t cluster_size;
QLIST_HEAD(, CowRequest) inflight_reqs;
} BackupBlockJob;
+/* Size of a cluster in sectors, instead of bytes. */
+static inline int64_t cluster_size_sectors(BackupBlockJob *job)
+{
+ return job->cluster_size / BDRV_SECTOR_SIZE;
+}
+
/* See if in-flight requests overlap and wait for them to complete */
static void coroutine_fn wait_for_overlapping_requests(BackupBlockJob *job,
int64_t start,
@@ -97,13 +101,14 @@ static int coroutine_fn backup_do_cow(BlockDriverState *bs,
QEMUIOVector bounce_qiov;
void *bounce_buffer = NULL;
int ret = 0;
+ int64_t sectors_per_cluster = cluster_size_sectors(job);
int64_t start, end;
int n;
qemu_co_rwlock_rdlock(&job->flush_rwlock);
- start = sector_num / BACKUP_SECTORS_PER_CLUSTER;
- end = DIV_ROUND_UP(sector_num + nb_sectors, BACKUP_SECTORS_PER_CLUSTER);
+ start = sector_num / sectors_per_cluster;
+ end = DIV_ROUND_UP(sector_num + nb_sectors, sectors_per_cluster);
trace_backup_do_cow_enter(job, start, sector_num, nb_sectors);
@@ -118,12 +123,12 @@ static int coroutine_fn backup_do_cow(BlockDriverState
*bs,
trace_backup_do_cow_process(job, start);
- n = MIN(BACKUP_SECTORS_PER_CLUSTER,
+ n = MIN(sectors_per_cluster,
job->common.len / BDRV_SECTOR_SIZE -
- start * BACKUP_SECTORS_PER_CLUSTER);
+ start * sectors_per_cluster);
if (!bounce_buffer) {
- bounce_buffer = qemu_blockalign(bs, BACKUP_CLUSTER_SIZE);
+ bounce_buffer = qemu_blockalign(bs, job->cluster_size);
}
iov.iov_base = bounce_buffer;
iov.iov_len = n * BDRV_SECTOR_SIZE;
@@ -131,10 +136,10 @@ static int coroutine_fn backup_do_cow(BlockDriverState
*bs,
if (is_write_notifier) {
ret = bdrv_co_readv_no_serialising(bs,
- start * BACKUP_SECTORS_PER_CLUSTER,
+ start * sectors_per_cluster,
n, &bounce_qiov);
} else {
- ret = bdrv_co_readv(bs, start * BACKUP_SECTORS_PER_CLUSTER, n,
+ ret = bdrv_co_readv(bs, start * sectors_per_cluster, n,
&bounce_qiov);
}
if (ret < 0) {
@@ -147,11 +152,11 @@ static int coroutine_fn backup_do_cow(BlockDriverState
*bs,
if (buffer_is_zero(iov.iov_base, iov.iov_len)) {
ret = bdrv_co_write_zeroes(job->target,
- start * BACKUP_SECTORS_PER_CLUSTER,
+ start * sectors_per_cluster,
n, BDRV_REQ_MAY_UNMAP);
} else {
ret = bdrv_co_writev(job->target,
- start * BACKUP_SECTORS_PER_CLUSTER, n,
+ start * sectors_per_cluster, n,
&bounce_qiov);
}
if (ret < 0) {
@@ -322,21 +327,22 @@ static int coroutine_fn
backup_run_incremental(BackupBlockJob *job)
int64_t cluster;
int64_t end;
int64_t last_cluster = -1;
+ int64_t sectors_per_cluster = cluster_size_sectors(job);
BlockDriverState *bs = job->common.bs;
HBitmapIter hbi;
granularity = bdrv_dirty_bitmap_granularity(job->sync_bitmap);
- clusters_per_iter = MAX((granularity / BACKUP_CLUSTER_SIZE), 1);
+ clusters_per_iter = MAX((granularity / job->cluster_size), 1);
bdrv_dirty_iter_init(job->sync_bitmap, &hbi);
/* Find the next dirty sector(s) */
while ((sector = hbitmap_iter_next(&hbi)) != -1) {
- cluster = sector / BACKUP_SECTORS_PER_CLUSTER;
+ cluster = sector / sectors_per_cluster;
/* Fake progress updates for any clusters we skipped */
if (cluster != last_cluster + 1) {
job->common.offset += ((cluster - last_cluster - 1) *
- BACKUP_CLUSTER_SIZE);
+ job->cluster_size);
}
for (end = cluster + clusters_per_iter; cluster < end; cluster++) {
@@ -344,8 +350,8 @@ static int coroutine_fn
backup_run_incremental(BackupBlockJob *job)
if (yield_and_check(job)) {
return ret;
}
- ret = backup_do_cow(bs, cluster * BACKUP_SECTORS_PER_CLUSTER,
- BACKUP_SECTORS_PER_CLUSTER, &error_is_read,
+ ret = backup_do_cow(bs, cluster * sectors_per_cluster,
+ sectors_per_cluster, &error_is_read,
false);
if ((ret < 0) &&
backup_error_action(job, error_is_read, -ret) ==
@@ -357,17 +363,17 @@ static int coroutine_fn
backup_run_incremental(BackupBlockJob *job)
/* If the bitmap granularity is smaller than the backup granularity,
* we need to advance the iterator pointer to the next cluster. */
- if (granularity < BACKUP_CLUSTER_SIZE) {
- bdrv_set_dirty_iter(&hbi, cluster * BACKUP_SECTORS_PER_CLUSTER);
+ if (granularity < job->cluster_size) {
+ bdrv_set_dirty_iter(&hbi, cluster * sectors_per_cluster);
}
last_cluster = cluster - 1;
}
/* Play some final catchup with the progress meter */
- end = DIV_ROUND_UP(job->common.len, BACKUP_CLUSTER_SIZE);
+ end = DIV_ROUND_UP(job->common.len, job->cluster_size);
if (last_cluster + 1 < end) {
- job->common.offset += ((end - last_cluster - 1) * BACKUP_CLUSTER_SIZE);
+ job->common.offset += ((end - last_cluster - 1) * job->cluster_size);
}
return ret;
@@ -384,13 +390,14 @@ static void coroutine_fn backup_run(void *opaque)
.notify = backup_before_write_notify,
};
int64_t start, end;
+ int64_t sectors_per_cluster = cluster_size_sectors(job);
int ret = 0;
QLIST_INIT(&job->inflight_reqs);
qemu_co_rwlock_init(&job->flush_rwlock);
start = 0;
- end = DIV_ROUND_UP(job->common.len, BACKUP_CLUSTER_SIZE);
+ end = DIV_ROUND_UP(job->common.len, job->cluster_size);
job->bitmap = hbitmap_alloc(end, 0);
@@ -427,7 +434,7 @@ static void coroutine_fn backup_run(void *opaque)
/* Check to see if these blocks are already in the
* backing file. */
- for (i = 0; i < BACKUP_SECTORS_PER_CLUSTER;) {
+ for (i = 0; i < sectors_per_cluster;) {
/* bdrv_is_allocated() only returns true/false based
* on the first set of sectors it comes across that
* are are all in the same state.
@@ -436,8 +443,8 @@ static void coroutine_fn backup_run(void *opaque)
* needed but at some point that is always the case. */
alloced =
bdrv_is_allocated(bs,
- start * BACKUP_SECTORS_PER_CLUSTER + i,
- BACKUP_SECTORS_PER_CLUSTER - i, &n);
+ start * sectors_per_cluster + i,
+ sectors_per_cluster - i, &n);
i += n;
if (alloced == 1 || n == 0) {
@@ -452,8 +459,8 @@ static void coroutine_fn backup_run(void *opaque)
}
}
/* FULL sync mode we copy the whole drive. */
- ret = backup_do_cow(bs, start * BACKUP_SECTORS_PER_CLUSTER,
- BACKUP_SECTORS_PER_CLUSTER, &error_is_read, false);
+ ret = backup_do_cow(bs, start * sectors_per_cluster,
+ sectors_per_cluster, &error_is_read, false);
if (ret < 0) {
/* Depending on error action, fail now or retry cluster */
BlockErrorAction action =
@@ -571,6 +578,7 @@ void backup_start(BlockDriverState *bs, BlockDriverState
*target,
job->sync_mode = sync_mode;
job->sync_bitmap = sync_mode == MIRROR_SYNC_MODE_INCREMENTAL ?
sync_bitmap : NULL;
+ job->cluster_size = BACKUP_CLUSTER_SIZE_DEFAULT;
job->common.len = len;
job->common.co = qemu_coroutine_create(backup_run);
block_job_txn_add_job(txn, &job->common);
--
1.9.3
