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Diffstat (limited to 'block/io.c')
-rw-r--r--block/io.c51
1 files changed, 31 insertions, 20 deletions
diff --git a/block/io.c b/block/io.c
index ed31810c0a..91611ffb2a 100644
--- a/block/io.c
+++ b/block/io.c
@@ -130,13 +130,13 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
*/
void bdrv_enable_copy_on_read(BlockDriverState *bs)
{
- bs->copy_on_read++;
+ atomic_inc(&bs->copy_on_read);
}
void bdrv_disable_copy_on_read(BlockDriverState *bs)
{
- assert(bs->copy_on_read > 0);
- bs->copy_on_read--;
+ int old = atomic_fetch_dec(&bs->copy_on_read);
+ assert(old >= 1);
}
/* Check if any requests are in-flight (including throttled requests) */
@@ -241,7 +241,7 @@ void bdrv_drained_begin(BlockDriverState *bs)
return;
}
- if (!bs->quiesce_counter++) {
+ if (atomic_fetch_inc(&bs->quiesce_counter) == 0) {
aio_disable_external(bdrv_get_aio_context(bs));
bdrv_parent_drained_begin(bs);
}
@@ -252,7 +252,7 @@ void bdrv_drained_begin(BlockDriverState *bs)
void bdrv_drained_end(BlockDriverState *bs)
{
assert(bs->quiesce_counter > 0);
- if (--bs->quiesce_counter > 0) {
+ if (atomic_fetch_dec(&bs->quiesce_counter) > 1) {
return;
}
@@ -375,11 +375,13 @@ void bdrv_drain_all(void)
static void tracked_request_end(BdrvTrackedRequest *req)
{
if (req->serialising) {
- req->bs->serialising_in_flight--;
+ atomic_dec(&req->bs->serialising_in_flight);
}
+ qemu_co_mutex_lock(&req->bs->reqs_lock);
QLIST_REMOVE(req, list);
qemu_co_queue_restart_all(&req->wait_queue);
+ qemu_co_mutex_unlock(&req->bs->reqs_lock);
}
/**
@@ -404,7 +406,9 @@ static void tracked_request_begin(BdrvTrackedRequest *req,
qemu_co_queue_init(&req->wait_queue);
+ qemu_co_mutex_lock(&bs->reqs_lock);
QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
+ qemu_co_mutex_unlock(&bs->reqs_lock);
}
static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
@@ -414,7 +418,7 @@ static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
- overlap_offset;
if (!req->serialising) {
- req->bs->serialising_in_flight++;
+ atomic_inc(&req->bs->serialising_in_flight);
req->serialising = true;
}
@@ -501,7 +505,8 @@ static void dummy_bh_cb(void *opaque)
void bdrv_wakeup(BlockDriverState *bs)
{
- if (bs->wakeup) {
+ /* The barrier (or an atomic op) is in the caller. */
+ if (atomic_read(&bs->wakeup)) {
aio_bh_schedule_oneshot(qemu_get_aio_context(), dummy_bh_cb, NULL);
}
}
@@ -519,12 +524,13 @@ static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
bool retry;
bool waited = false;
- if (!bs->serialising_in_flight) {
+ if (!atomic_read(&bs->serialising_in_flight)) {
return false;
}
do {
retry = false;
+ qemu_co_mutex_lock(&bs->reqs_lock);
QLIST_FOREACH(req, &bs->tracked_requests, list) {
if (req == self || (!req->serialising && !self->serialising)) {
continue;
@@ -543,7 +549,7 @@ static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
* (instead of producing a deadlock in the former case). */
if (!req->waiting_for) {
self->waiting_for = req;
- qemu_co_queue_wait(&req->wait_queue, NULL);
+ qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock);
self->waiting_for = NULL;
retry = true;
waited = true;
@@ -551,6 +557,7 @@ static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
}
}
}
+ qemu_co_mutex_unlock(&bs->reqs_lock);
} while (retry);
return waited;
@@ -1144,7 +1151,7 @@ int coroutine_fn bdrv_co_preadv(BdrvChild *child,
bdrv_inc_in_flight(bs);
/* Don't do copy-on-read if we read data before write operation */
- if (bs->copy_on_read && !(flags & BDRV_REQ_NO_SERIALISING)) {
+ if (atomic_read(&bs->copy_on_read) && !(flags & BDRV_REQ_NO_SERIALISING)) {
flags |= BDRV_REQ_COPY_ON_READ;
}
@@ -1401,12 +1408,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
}
bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE);
- ++bs->write_gen;
+ atomic_inc(&bs->write_gen);
bdrv_set_dirty(bs, start_sector, end_sector - start_sector);
- if (bs->wr_highest_offset < offset + bytes) {
- bs->wr_highest_offset = offset + bytes;
- }
+ stat64_max(&bs->wr_highest_offset, offset + bytes);
if (ret >= 0) {
bs->total_sectors = MAX(bs->total_sectors, end_sector);
@@ -2292,14 +2297,17 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
goto early_exit;
}
- current_gen = bs->write_gen;
+ qemu_co_mutex_lock(&bs->reqs_lock);
+ current_gen = atomic_read(&bs->write_gen);
/* Wait until any previous flushes are completed */
while (bs->active_flush_req) {
- qemu_co_queue_wait(&bs->flush_queue, NULL);
+ qemu_co_queue_wait(&bs->flush_queue, &bs->reqs_lock);
}
+ /* Flushes reach this point in nondecreasing current_gen order. */
bs->active_flush_req = true;
+ qemu_co_mutex_unlock(&bs->reqs_lock);
/* Write back all layers by calling one driver function */
if (bs->drv->bdrv_co_flush) {
@@ -2371,9 +2379,12 @@ out:
if (ret == 0) {
bs->flushed_gen = current_gen;
}
+
+ qemu_co_mutex_lock(&bs->reqs_lock);
bs->active_flush_req = false;
/* Return value is ignored - it's ok if wait queue is empty */
qemu_co_queue_next(&bs->flush_queue);
+ qemu_co_mutex_unlock(&bs->reqs_lock);
early_exit:
bdrv_dec_in_flight(bs);
@@ -2517,7 +2528,7 @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset,
}
ret = 0;
out:
- ++bs->write_gen;
+ atomic_inc(&bs->write_gen);
bdrv_set_dirty(bs, req.offset >> BDRV_SECTOR_BITS,
req.bytes >> BDRV_SECTOR_BITS);
tracked_request_end(&req);
@@ -2644,7 +2655,7 @@ void bdrv_io_plug(BlockDriverState *bs)
bdrv_io_plug(child->bs);
}
- if (bs->io_plugged++ == 0) {
+ if (atomic_fetch_inc(&bs->io_plugged) == 0) {
BlockDriver *drv = bs->drv;
if (drv && drv->bdrv_io_plug) {
drv->bdrv_io_plug(bs);
@@ -2657,7 +2668,7 @@ void bdrv_io_unplug(BlockDriverState *bs)
BdrvChild *child;
assert(bs->io_plugged);
- if (--bs->io_plugged == 0) {
+ if (atomic_fetch_dec(&bs->io_plugged) == 1) {
BlockDriver *drv = bs->drv;
if (drv && drv->bdrv_io_unplug) {
drv->bdrv_io_unplug(bs);
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-23 19:27:47 +0000