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block: Switch BdrvTrackedRequest to byte granularity 

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
This commit is contained in:
Kevin Wolf 2013-12-03 15:31:25 +01:00
parent 6601553e27
commit 793ed47a7a
3 changed files with 42 additions and 21 deletions
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52
block.c
View File

@ -2217,13 +2217,13 @@ static void tracked_request_end(BdrvTrackedRequest *req)
*/
static void tracked_request_begin(BdrvTrackedRequest *req,
BlockDriverState *bs,
int64_t sector_num,
int nb_sectors, bool is_write)
int64_t offset,
unsigned int bytes, bool is_write)
{
*req = (BdrvTrackedRequest){
.bs = bs,
.sector_num = sector_num,
.nb_sectors = nb_sectors,
.offset = offset,
.bytes = bytes,
.is_write = is_write,
.co = qemu_coroutine_self(),
};
@ -2254,25 +2254,43 @@ void bdrv_round_to_clusters(BlockDriverState *bs,
}
}
static void round_bytes_to_clusters(BlockDriverState *bs,
int64_t offset, unsigned int bytes,
int64_t *cluster_offset,
unsigned int *cluster_bytes)
{
BlockDriverInfo bdi;
if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) {
*cluster_offset = offset;
*cluster_bytes = bytes;
} else {
*cluster_offset = QEMU_ALIGN_DOWN(offset, bdi.cluster_size);
*cluster_bytes = QEMU_ALIGN_UP(offset - *cluster_offset + bytes,
bdi.cluster_size);
}
}
static bool tracked_request_overlaps(BdrvTrackedRequest *req,
int64_t sector_num, int nb_sectors) {
int64_t offset, unsigned int bytes)
{
/* aaaa bbbb */
if (sector_num >= req->sector_num + req->nb_sectors) {
if (offset >= req->offset + req->bytes) {
return false;
}
/* bbbb aaaa */
if (req->sector_num >= sector_num + nb_sectors) {
if (req->offset >= offset + bytes) {
return false;
}
return true;
}
static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs,
int64_t sector_num, int nb_sectors)
int64_t offset, unsigned int bytes)
{
BdrvTrackedRequest *req;
int64_t cluster_sector_num;
int cluster_nb_sectors;
int64_t cluster_offset;
unsigned int cluster_bytes;
bool retry;
/* If we touch the same cluster it counts as an overlap. This guarantees
@ -2281,14 +2299,12 @@ static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs,
* CoR read and write operations are atomic and guest writes cannot
* interleave between them.
*/
bdrv_round_to_clusters(bs, sector_num, nb_sectors,
&cluster_sector_num, &cluster_nb_sectors);
round_bytes_to_clusters(bs, offset, bytes, &cluster_offset, &cluster_bytes);
do {
retry = false;
QLIST_FOREACH(req, &bs->tracked_requests, list) {
if (tracked_request_overlaps(req, cluster_sector_num,
cluster_nb_sectors)) {
if (tracked_request_overlaps(req, cluster_offset, cluster_bytes)) {
/* Hitting this means there was a reentrant request, for
* example, a block driver issuing nested requests. This must
* never happen since it means deadlock.
@ -2908,10 +2924,10 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
}
if (bs->copy_on_read_in_flight) {
wait_for_overlapping_requests(bs, sector_num, nb_sectors);
wait_for_overlapping_requests(bs, offset, bytes);
}
tracked_request_begin(&req, bs, sector_num, nb_sectors, false);
tracked_request_begin(&req, bs, offset, bytes, false);
if (flags & BDRV_REQ_COPY_ON_READ) {
int pnum;
@ -3160,10 +3176,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
if (bs->copy_on_read_in_flight) {
wait_for_overlapping_requests(bs, sector_num, nb_sectors);
wait_for_overlapping_requests(bs, offset, bytes);
}
tracked_request_begin(&req, bs, sector_num, nb_sectors, true);
tracked_request_begin(&req, bs, offset, bytes, true);
ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req);

7
block/backup.c
View File

@ -181,8 +181,13 @@ static int coroutine_fn backup_before_write_notify(
void *opaque)
{
BdrvTrackedRequest *req = opaque;
int64_t sector_num = req->offset >> BDRV_SECTOR_BITS;
int nb_sectors = req->bytes >> BDRV_SECTOR_BITS;
return backup_do_cow(req->bs, req->sector_num, req->nb_sectors, NULL);
assert((req->offset & (BDRV_SECTOR_SIZE - 1)) == 0);
assert((req->bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
return backup_do_cow(req->bs, sector_num, nb_sectors, NULL);
}
static void backup_set_speed(BlockJob *job, int64_t speed, Error **errp)

4
include/block/block_int.h
View File

@ -57,8 +57,8 @@
typedef struct BdrvTrackedRequest {
BlockDriverState *bs;
int64_t sector_num;
int nb_sectors;
int64_t offset;
unsigned int bytes;
bool is_write;
QLIST_ENTRY(BdrvTrackedRequest) list;
Coroutine *co; /* owner, used for deadlock detection */