diff --git a/block.c b/block.c
index fa1d06d846..694396281b 100644
--- a/block.c
+++ b/block.c
@@ -320,6 +320,8 @@ BlockDriverState *bdrv_new(void)
QLIST_INIT(&bs->op_blockers[i]);
}
notifier_with_return_list_init(&bs->before_write_notifiers);
+ qemu_co_mutex_init(&bs->reqs_lock);
+ qemu_mutex_init(&bs->dirty_bitmap_mutex);
bs->refcnt = 1;
bs->aio_context = qemu_get_aio_context();
@@ -1300,7 +1302,9 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
goto fail_opts;
}
- assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */
+ /* bdrv_new() and bdrv_close() make it so */
+ assert(atomic_read(&bs->copy_on_read) == 0);
+
if (bs->open_flags & BDRV_O_COPY_ON_READ) {
if (!bs->read_only) {
bdrv_enable_copy_on_read(bs);
@@ -3063,7 +3067,7 @@ static void bdrv_close(BlockDriverState *bs)
g_free(bs->opaque);
bs->opaque = NULL;
- bs->copy_on_read = 0;
+ atomic_set(&bs->copy_on_read, 0);
bs->backing_file[0] = '\0';
bs->backing_format[0] = '\0';
bs->total_sectors = 0;
@@ -3422,7 +3426,7 @@ int bdrv_truncate(BdrvChild *child, int64_t offset, Error **errp)
ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
bdrv_dirty_bitmap_truncate(bs);
bdrv_parent_cb_resize(bs);
- ++bs->write_gen;
+ atomic_inc(&bs->write_gen);
}
return ret;
}
diff --git a/block/accounting.c b/block/accounting.c
index 3f457c4e73..87ef5bbfaa 100644
--- a/block/accounting.c
+++ b/block/accounting.c
@@ -32,23 +32,28 @@
static QEMUClockType clock_type = QEMU_CLOCK_REALTIME;
static const int qtest_latency_ns = NANOSECONDS_PER_SECOND / 1000;
-void block_acct_init(BlockAcctStats *stats, bool account_invalid,
- bool account_failed)
+void block_acct_init(BlockAcctStats *stats)
{
- stats->account_invalid = account_invalid;
- stats->account_failed = account_failed;
-
+ qemu_mutex_init(&stats->lock);
if (qtest_enabled()) {
clock_type = QEMU_CLOCK_VIRTUAL;
}
}
+void block_acct_setup(BlockAcctStats *stats, bool account_invalid,
+ bool account_failed)
+{
+ stats->account_invalid = account_invalid;
+ stats->account_failed = account_failed;
+}
+
void block_acct_cleanup(BlockAcctStats *stats)
{
BlockAcctTimedStats *s, *next;
QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) {
g_free(s);
}
+ qemu_mutex_destroy(&stats->lock);
}
void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
@@ -58,12 +63,15 @@ void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
s = g_new0(BlockAcctTimedStats, 1);
s->interval_length = interval_length;
+ s->stats = stats;
+ qemu_mutex_lock(&stats->lock);
QSLIST_INSERT_HEAD(&stats->intervals, s, entries);
for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
timed_average_init(&s->latency[i], clock_type,
(uint64_t) interval_length * NANOSECONDS_PER_SECOND);
}
+ qemu_mutex_unlock(&stats->lock);
}
BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats,
@@ -86,7 +94,8 @@ void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
cookie->type = type;
}
-void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
+static void block_account_one_io(BlockAcctStats *stats, BlockAcctCookie *cookie,
+ bool failed)
{
BlockAcctTimedStats *s;
int64_t time_ns = qemu_clock_get_ns(clock_type);
@@ -98,31 +107,16 @@ void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
assert(cookie->type < BLOCK_MAX_IOTYPE);
- stats->nr_bytes[cookie->type] += cookie->bytes;
- stats->nr_ops[cookie->type]++;
- stats->total_time_ns[cookie->type] += latency_ns;
- stats->last_access_time_ns = time_ns;
+ qemu_mutex_lock(&stats->lock);
- QSLIST_FOREACH(s, &stats->intervals, entries) {
- timed_average_account(&s->latency[cookie->type], latency_ns);
+ if (failed) {
+ stats->failed_ops[cookie->type]++;
+ } else {
+ stats->nr_bytes[cookie->type] += cookie->bytes;
+ stats->nr_ops[cookie->type]++;
}
-}
-
-void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
-{
- assert(cookie->type < BLOCK_MAX_IOTYPE);
-
- stats->failed_ops[cookie->type]++;
-
- if (stats->account_failed) {
- BlockAcctTimedStats *s;
- int64_t time_ns = qemu_clock_get_ns(clock_type);
- int64_t latency_ns = time_ns - cookie->start_time_ns;
-
- if (qtest_enabled()) {
- latency_ns = qtest_latency_ns;
- }
+ if (!failed || stats->account_failed) {
stats->total_time_ns[cookie->type] += latency_ns;
stats->last_access_time_ns = time_ns;
@@ -130,29 +124,45 @@ void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
timed_average_account(&s->latency[cookie->type], latency_ns);
}
}
+
+ qemu_mutex_unlock(&stats->lock);
+}
+
+void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
+{
+ block_account_one_io(stats, cookie, false);
+}
+
+void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
+{
+ block_account_one_io(stats, cookie, true);
}
void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type)
{
assert(type < BLOCK_MAX_IOTYPE);
- /* block_acct_done() and block_acct_failed() update
- * total_time_ns[], but this one does not. The reason is that
- * invalid requests are accounted during their submission,
- * therefore there's no actual I/O involved. */
-
+ /* block_account_one_io() updates total_time_ns[], but this one does
+ * not. The reason is that invalid requests are accounted during their
+ * submission, therefore there's no actual I/O involved.
+ */
+ qemu_mutex_lock(&stats->lock);
stats->invalid_ops[type]++;
if (stats->account_invalid) {
stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
}
+ qemu_mutex_unlock(&stats->lock);
}
void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
int num_requests)
{
assert(type < BLOCK_MAX_IOTYPE);
+
+ qemu_mutex_lock(&stats->lock);
stats->merged[type] += num_requests;
+ qemu_mutex_unlock(&stats->lock);
}
int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
@@ -167,7 +177,9 @@ double block_acct_queue_depth(BlockAcctTimedStats *stats,
assert(type < BLOCK_MAX_IOTYPE);
+ qemu_mutex_lock(&stats->stats->lock);
sum = timed_average_sum(&stats->latency[type], &elapsed);
+ qemu_mutex_unlock(&stats->stats->lock);
return (double) sum / elapsed;
}
diff --git a/block/block-backend.c b/block/block-backend.c
index 7d7f3697d1..a2bbae90b1 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -216,8 +216,10 @@ BlockBackend *blk_new(uint64_t perm, uint64_t shared_perm)
blk->shared_perm = shared_perm;
blk_set_enable_write_cache(blk, true);
+ qemu_co_mutex_init(&blk->public.throttled_reqs_lock);
qemu_co_queue_init(&blk->public.throttled_reqs[0]);
qemu_co_queue_init(&blk->public.throttled_reqs[1]);
+ block_acct_init(&blk->stats);
notifier_list_init(&blk->remove_bs_notifiers);
notifier_list_init(&blk->insert_bs_notifiers);
@@ -1953,7 +1955,7 @@ static void blk_root_drained_begin(BdrvChild *child)
/* Note that blk->root may not be accessible here yet if we are just
* attaching to a BlockDriverState that is drained. Use child instead. */
- if (blk->public.io_limits_disabled++ == 0) {
+ if (atomic_fetch_inc(&blk->public.io_limits_disabled) == 0) {
throttle_group_restart_blk(blk);
}
}
@@ -1964,7 +1966,7 @@ static void blk_root_drained_end(BdrvChild *child)
assert(blk->quiesce_counter);
assert(blk->public.io_limits_disabled);
- --blk->public.io_limits_disabled;
+ atomic_dec(&blk->public.io_limits_disabled);
if (--blk->quiesce_counter == 0) {
if (blk->dev_ops && blk->dev_ops->drained_end) {
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 519737c8d3..a04c6e4154 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -37,6 +37,7 @@
* or enabled. A frozen bitmap can only abdicate() or reclaim().
*/
struct BdrvDirtyBitmap {
+ QemuMutex *mutex;
HBitmap *bitmap; /* Dirty sector bitmap implementation */
HBitmap *meta; /* Meta dirty bitmap */
BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
@@ -52,6 +53,27 @@ struct BdrvDirtyBitmapIter {
BdrvDirtyBitmap *bitmap;
};
+static inline void bdrv_dirty_bitmaps_lock(BlockDriverState *bs)
+{
+ qemu_mutex_lock(&bs->dirty_bitmap_mutex);
+}
+
+static inline void bdrv_dirty_bitmaps_unlock(BlockDriverState *bs)
+{
+ qemu_mutex_unlock(&bs->dirty_bitmap_mutex);
+}
+
+void bdrv_dirty_bitmap_lock(BdrvDirtyBitmap *bitmap)
+{
+ qemu_mutex_lock(bitmap->mutex);
+}
+
+void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap)
+{
+ qemu_mutex_unlock(bitmap->mutex);
+}
+
+/* Called with BQL or dirty_bitmap lock taken. */
BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
{
BdrvDirtyBitmap *bm;
@@ -65,6 +87,7 @@ BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
return NULL;
}
+/* Called with BQL taken. */
void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
{
assert(!bdrv_dirty_bitmap_frozen(bitmap));
@@ -72,6 +95,7 @@ void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
bitmap->name = NULL;
}
+/* Called with BQL taken. */
BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
uint32_t granularity,
const char *name,
@@ -96,11 +120,14 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
return NULL;
}
bitmap = g_new0(BdrvDirtyBitmap, 1);
+ bitmap->mutex = &bs->dirty_bitmap_mutex;
bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity));
bitmap->size = bitmap_size;
bitmap->name = g_strdup(name);
bitmap->disabled = false;
+ bdrv_dirty_bitmaps_lock(bs);
QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
+ bdrv_dirty_bitmaps_unlock(bs);
return bitmap;
}
@@ -119,20 +146,24 @@ void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap,
int chunk_size)
{
assert(!bitmap->meta);
+ qemu_mutex_lock(bitmap->mutex);
bitmap->meta = hbitmap_create_meta(bitmap->bitmap,
chunk_size * BITS_PER_BYTE);
+ qemu_mutex_unlock(bitmap->mutex);
}
void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap)
{
assert(bitmap->meta);
+ qemu_mutex_lock(bitmap->mutex);
hbitmap_free_meta(bitmap->bitmap);
bitmap->meta = NULL;
+ qemu_mutex_unlock(bitmap->mutex);
}
-int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
- BdrvDirtyBitmap *bitmap, int64_t sector,
- int nb_sectors)
+int bdrv_dirty_bitmap_get_meta_locked(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap, int64_t sector,
+ int nb_sectors)
{
uint64_t i;
int sectors_per_bit = 1 << hbitmap_granularity(bitmap->meta);
@@ -147,11 +178,26 @@ int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
return false;
}
+int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap, int64_t sector,
+ int nb_sectors)
+{
+ bool dirty;
+
+ qemu_mutex_lock(bitmap->mutex);
+ dirty = bdrv_dirty_bitmap_get_meta_locked(bs, bitmap, sector, nb_sectors);
+ qemu_mutex_unlock(bitmap->mutex);
+
+ return dirty;
+}
+
void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap, int64_t sector,
int nb_sectors)
{
+ qemu_mutex_lock(bitmap->mutex);
hbitmap_reset(bitmap->meta, sector, nb_sectors);
+ qemu_mutex_unlock(bitmap->mutex);
}
int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap)
@@ -164,16 +210,19 @@ const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap)
return bitmap->name;
}
+/* Called with BQL taken. */
bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap)
{
return bitmap->successor;
}
+/* Called with BQL taken. */
bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap)
{
return !(bitmap->disabled || bitmap->successor);
}
+/* Called with BQL taken. */
DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap)
{
if (bdrv_dirty_bitmap_frozen(bitmap)) {
@@ -188,6 +237,7 @@ DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap)
/**
* Create a successor bitmap destined to replace this bitmap after an operation.
* Requires that the bitmap is not frozen and has no successor.
+ * Called with BQL taken.
*/
int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap, Error **errp)
@@ -220,6 +270,7 @@ int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
/**
* For a bitmap with a successor, yield our name to the successor,
* delete the old bitmap, and return a handle to the new bitmap.
+ * Called with BQL taken.
*/
BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap,
@@ -247,6 +298,7 @@ BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
* In cases of failure where we can no longer safely delete the parent,
* we may wish to re-join the parent and child/successor.
* The merged parent will be un-frozen, but not explicitly re-enabled.
+ * Called with BQL taken.
*/
BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
BdrvDirtyBitmap *parent,
@@ -271,25 +323,30 @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
/**
* Truncates _all_ bitmaps attached to a BDS.
+ * Called with BQL taken.
*/
void bdrv_dirty_bitmap_truncate(BlockDriverState *bs)
{
BdrvDirtyBitmap *bitmap;
uint64_t size = bdrv_nb_sectors(bs);
+ bdrv_dirty_bitmaps_lock(bs);
QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
assert(!bdrv_dirty_bitmap_frozen(bitmap));
assert(!bitmap->active_iterators);
hbitmap_truncate(bitmap->bitmap, size);
bitmap->size = size;
}
+ bdrv_dirty_bitmaps_unlock(bs);
}
+/* Called with BQL taken. */
static void bdrv_do_release_matching_dirty_bitmap(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap,
bool only_named)
{
BdrvDirtyBitmap *bm, *next;
+ bdrv_dirty_bitmaps_lock(bs);
QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) {
if ((!bitmap || bm == bitmap) && (!only_named || bm->name)) {
assert(!bm->active_iterators);
@@ -301,15 +358,19 @@ static void bdrv_do_release_matching_dirty_bitmap(BlockDriverState *bs,
g_free(bm);
if (bitmap) {
- return;
+ goto out;
}
}
}
if (bitmap) {
abort();
}
+
+out:
+ bdrv_dirty_bitmaps_unlock(bs);
}
+/* Called with BQL taken. */
void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
{
bdrv_do_release_matching_dirty_bitmap(bs, bitmap, false);
@@ -318,18 +379,21 @@ void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
/**
* Release all named dirty bitmaps attached to a BDS (for use in bdrv_close()).
* There must not be any frozen bitmaps attached.
+ * Called with BQL taken.
*/
void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs)
{
bdrv_do_release_matching_dirty_bitmap(bs, NULL, true);
}
+/* Called with BQL taken. */
void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
{
assert(!bdrv_dirty_bitmap_frozen(bitmap));
bitmap->disabled = true;
}
+/* Called with BQL taken. */
void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
{
assert(!bdrv_dirty_bitmap_frozen(bitmap));
@@ -342,6 +406,7 @@ BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
BlockDirtyInfoList *list = NULL;
BlockDirtyInfoList **plist = &list;
+ bdrv_dirty_bitmaps_lock(bs);
QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1);
BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1);
@@ -354,12 +419,14 @@ BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
*plist = entry;
plist = &entry->next;
}
+ bdrv_dirty_bitmaps_unlock(bs);
return list;
}
-int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
- int64_t sector)
+/* Called within bdrv_dirty_bitmap_lock..unlock */
+int bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+ int64_t sector)
{
if (bitmap) {
return hbitmap_get(bitmap->bitmap, sector);
@@ -432,23 +499,42 @@ int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
return hbitmap_iter_next(&iter->hbi);
}
-void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
- int64_t cur_sector, int64_t nr_sectors)
+/* Called within bdrv_dirty_bitmap_lock..unlock */
+void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
+ int64_t cur_sector, int64_t nr_sectors)
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
}
-void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
- int64_t cur_sector, int64_t nr_sectors)
+void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+ int64_t cur_sector, int64_t nr_sectors)
+{
+ bdrv_dirty_bitmap_lock(bitmap);
+ bdrv_set_dirty_bitmap_locked(bitmap, cur_sector, nr_sectors);
+ bdrv_dirty_bitmap_unlock(bitmap);
+}
+
+/* Called within bdrv_dirty_bitmap_lock..unlock */
+void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
+ int64_t cur_sector, int64_t nr_sectors)
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
}
+void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+ int64_t cur_sector, int64_t nr_sectors)
+{
+ bdrv_dirty_bitmap_lock(bitmap);
+ bdrv_reset_dirty_bitmap_locked(bitmap, cur_sector, nr_sectors);
+ bdrv_dirty_bitmap_unlock(bitmap);
+}
+
void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
+ bdrv_dirty_bitmap_lock(bitmap);
if (!out) {
hbitmap_reset_all(bitmap->bitmap);
} else {
@@ -457,6 +543,7 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
hbitmap_granularity(backup));
*out = backup;
}
+ bdrv_dirty_bitmap_unlock(bitmap);
}
void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in)
@@ -508,12 +595,19 @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
int64_t nr_sectors)
{
BdrvDirtyBitmap *bitmap;
+
+ if (QLIST_EMPTY(&bs->dirty_bitmaps)) {
+ return;
+ }
+
+ bdrv_dirty_bitmaps_lock(bs);
QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
if (!bdrv_dirty_bitmap_enabled(bitmap)) {
continue;
}
hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
}
+ bdrv_dirty_bitmaps_unlock(bs);
}
/**
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);
diff --git a/block/mirror.c b/block/mirror.c
index a2a970301c..19afcc6f1a 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -342,6 +342,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
int max_io_sectors = MAX((s->buf_size >> BDRV_SECTOR_BITS) / MAX_IN_FLIGHT,
MAX_IO_SECTORS);
+ bdrv_dirty_bitmap_lock(s->dirty_bitmap);
sector_num = bdrv_dirty_iter_next(s->dbi);
if (sector_num < 0) {
bdrv_set_dirty_iter(s->dbi, 0);
@@ -349,6 +350,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap));
assert(sector_num >= 0);
}
+ bdrv_dirty_bitmap_unlock(s->dirty_bitmap);
first_chunk = sector_num / sectors_per_chunk;
while (test_bit(first_chunk, s->in_flight_bitmap)) {
@@ -360,12 +362,13 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
/* Find the number of consective dirty chunks following the first dirty
* one, and wait for in flight requests in them. */
+ bdrv_dirty_bitmap_lock(s->dirty_bitmap);
while (nb_chunks * sectors_per_chunk < (s->buf_size >> BDRV_SECTOR_BITS)) {
int64_t next_dirty;
int64_t next_sector = sector_num + nb_chunks * sectors_per_chunk;
int64_t next_chunk = next_sector / sectors_per_chunk;
if (next_sector >= end ||
- !bdrv_get_dirty(source, s->dirty_bitmap, next_sector)) {
+ !bdrv_get_dirty_locked(source, s->dirty_bitmap, next_sector)) {
break;
}
if (test_bit(next_chunk, s->in_flight_bitmap)) {
@@ -386,8 +389,10 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
* calling bdrv_get_block_status_above could yield - if some blocks are
* marked dirty in this window, we need to know.
*/
- bdrv_reset_dirty_bitmap(s->dirty_bitmap, sector_num,
- nb_chunks * sectors_per_chunk);
+ bdrv_reset_dirty_bitmap_locked(s->dirty_bitmap, sector_num,
+ nb_chunks * sectors_per_chunk);
+ bdrv_dirty_bitmap_unlock(s->dirty_bitmap);
+
bitmap_set(s->in_flight_bitmap, sector_num / sectors_per_chunk, nb_chunks);
while (nb_chunks > 0 && sector_num < end) {
int64_t ret;
@@ -506,6 +511,8 @@ static void mirror_exit(BlockJob *job, void *opaque)
BlockDriverState *mirror_top_bs = s->mirror_top_bs;
Error *local_err = NULL;
+ bdrv_release_dirty_bitmap(src, s->dirty_bitmap);
+
/* Make sure that the source BDS doesn't go away before we called
* block_job_completed(). */
bdrv_ref(src);
@@ -904,7 +911,6 @@ immediate_exit:
g_free(s->cow_bitmap);
g_free(s->in_flight_bitmap);
bdrv_dirty_iter_free(s->dbi);
- bdrv_release_dirty_bitmap(bs, s->dirty_bitmap);
data = g_malloc(sizeof(*data));
data->ret = ret;
diff --git a/block/nfs.c b/block/nfs.c
index 848b2c0bb0..18c87d2f25 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -730,7 +730,9 @@ nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
if (task->ret < 0) {
error_report("NFS Error: %s", nfs_get_error(nfs));
}
- task->complete = 1;
+
+ /* Set task->complete before reading bs->wakeup. */
+ atomic_mb_set(&task->complete, 1);
bdrv_wakeup(task->bs);
}
diff --git a/block/qapi.c b/block/qapi.c
index a40922ea26..14b60ae66c 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -441,7 +441,7 @@ static BlockStats *bdrv_query_bds_stats(const BlockDriverState *bs,
s->node_name = g_strdup(bdrv_get_node_name(bs));
}
- s->stats->wr_highest_offset = bs->wr_highest_offset;
+ s->stats->wr_highest_offset = stat64_get(&bs->wr_highest_offset);
if (bs->file) {
s->has_parent = true;
diff --git a/block/sheepdog.c b/block/sheepdog.c
index a18315a1ca..5ebf5d9fbb 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -698,7 +698,8 @@ out:
srco->co = NULL;
srco->ret = ret;
- srco->finished = true;
+ /* Set srco->finished before reading bs->wakeup. */
+ atomic_mb_set(&srco->finished, true);
if (srco->bs) {
bdrv_wakeup(srco->bs);
}
diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index b73e7a800b..a181cb1dee 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -240,7 +240,7 @@ static bool throttle_group_schedule_timer(BlockBackend *blk, bool is_write)
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
bool must_wait;
- if (blkp->io_limits_disabled) {
+ if (atomic_read(&blkp->io_limits_disabled)) {
return false;
}
@@ -260,6 +260,25 @@ static bool throttle_group_schedule_timer(BlockBackend *blk, bool is_write)
return must_wait;
}
+/* Start the next pending I/O request for a BlockBackend. Return whether
+ * any request was actually pending.
+ *
+ * @blk: the current BlockBackend
+ * @is_write: the type of operation (read/write)
+ */
+static bool coroutine_fn throttle_group_co_restart_queue(BlockBackend *blk,
+ bool is_write)
+{
+ BlockBackendPublic *blkp = blk_get_public(blk);
+ bool ret;
+
+ qemu_co_mutex_lock(&blkp->throttled_reqs_lock);
+ ret = qemu_co_queue_next(&blkp->throttled_reqs[is_write]);
+ qemu_co_mutex_unlock(&blkp->throttled_reqs_lock);
+
+ return ret;
+}
+
/* Look for the next pending I/O request and schedule it.
*
* This assumes that tg->lock is held.
@@ -287,12 +306,12 @@ static void schedule_next_request(BlockBackend *blk, bool is_write)
if (!must_wait) {
/* Give preference to requests from the current blk */
if (qemu_in_coroutine() &&
- qemu_co_queue_next(&blkp->throttled_reqs[is_write])) {
+ throttle_group_co_restart_queue(blk, is_write)) {
token = blk;
} else {
ThrottleTimers *tt = &blk_get_public(token)->throttle_timers;
int64_t now = qemu_clock_get_ns(tt->clock_type);
- timer_mod(tt->timers[is_write], now + 1);
+ timer_mod(tt->timers[is_write], now);
tg->any_timer_armed[is_write] = true;
}
tg->tokens[is_write] = token;
@@ -326,7 +345,10 @@ void coroutine_fn throttle_group_co_io_limits_intercept(BlockBackend *blk,
if (must_wait || blkp->pending_reqs[is_write]) {
blkp->pending_reqs[is_write]++;
qemu_mutex_unlock(&tg->lock);
- qemu_co_queue_wait(&blkp->throttled_reqs[is_write], NULL);
+ qemu_co_mutex_lock(&blkp->throttled_reqs_lock);
+ qemu_co_queue_wait(&blkp->throttled_reqs[is_write],
+ &blkp->throttled_reqs_lock);
+ qemu_co_mutex_unlock(&blkp->throttled_reqs_lock);
qemu_mutex_lock(&tg->lock);
blkp->pending_reqs[is_write]--;
}
@@ -340,15 +362,50 @@ void coroutine_fn throttle_group_co_io_limits_intercept(BlockBackend *blk,
qemu_mutex_unlock(&tg->lock);
}
+typedef struct {
+ BlockBackend *blk;
+ bool is_write;
+} RestartData;
+
+static void coroutine_fn throttle_group_restart_queue_entry(void *opaque)
+{
+ RestartData *data = opaque;
+ BlockBackend *blk = data->blk;
+ bool is_write = data->is_write;
+ BlockBackendPublic *blkp = blk_get_public(blk);
+ ThrottleGroup *tg = container_of(blkp->throttle_state, ThrottleGroup, ts);
+ bool empty_queue;
+
+ empty_queue = !throttle_group_co_restart_queue(blk, is_write);
+
+ /* If the request queue was empty then we have to take care of
+ * scheduling the next one */
+ if (empty_queue) {
+ qemu_mutex_lock(&tg->lock);
+ schedule_next_request(blk, is_write);
+ qemu_mutex_unlock(&tg->lock);
+ }
+}
+
+static void throttle_group_restart_queue(BlockBackend *blk, bool is_write)
+{
+ Coroutine *co;
+ RestartData rd = {
+ .blk = blk,
+ .is_write = is_write
+ };
+
+ co = qemu_coroutine_create(throttle_group_restart_queue_entry, &rd);
+ aio_co_enter(blk_get_aio_context(blk), co);
+}
+
void throttle_group_restart_blk(BlockBackend *blk)
{
BlockBackendPublic *blkp = blk_get_public(blk);
- int i;
- for (i = 0; i < 2; i++) {
- while (qemu_co_enter_next(&blkp->throttled_reqs[i])) {
- ;
- }
+ if (blkp->throttle_state) {
+ throttle_group_restart_queue(blk, 0);
+ throttle_group_restart_queue(blk, 1);
}
}
@@ -376,8 +433,7 @@ void throttle_group_config(BlockBackend *blk, ThrottleConfig *cfg)
throttle_config(ts, tt, cfg);
qemu_mutex_unlock(&tg->lock);
- qemu_co_enter_next(&blkp->throttled_reqs[0]);
- qemu_co_enter_next(&blkp->throttled_reqs[1]);
+ throttle_group_restart_blk(blk);
}
/* Get the throttle configuration from a particular group. Similar to
@@ -408,7 +464,6 @@ static void timer_cb(BlockBackend *blk, bool is_write)
BlockBackendPublic *blkp = blk_get_public(blk);
ThrottleState *ts = blkp->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
- bool empty_queue;
/* The timer has just been fired, so we can update the flag */
qemu_mutex_lock(&tg->lock);
@@ -416,17 +471,7 @@ static void timer_cb(BlockBackend *blk, bool is_write)
qemu_mutex_unlock(&tg->lock);
/* Run the request that was waiting for this timer */
- aio_context_acquire(blk_get_aio_context(blk));
- empty_queue = !qemu_co_enter_next(&blkp->throttled_reqs[is_write]);
- aio_context_release(blk_get_aio_context(blk));
-
- /* If the request queue was empty then we have to take care of
- * scheduling the next one */
- if (empty_queue) {
- qemu_mutex_lock(&tg->lock);
- schedule_next_request(blk, is_write);
- qemu_mutex_unlock(&tg->lock);
- }
+ throttle_group_restart_queue(blk, is_write);
}
static void read_timer_cb(void *opaque)
diff --git a/blockdev.c b/blockdev.c
index 6472548186..39d6b9712b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -595,7 +595,7 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
autostart = 0;
}
- block_acct_init(blk_get_stats(blk), account_invalid, account_failed);
+ block_acct_setup(blk_get_stats(blk), account_invalid, account_failed);
if (!parse_stats_intervals(blk_get_stats(blk), interval_list, errp)) {
blk_unref(blk);
@@ -1362,12 +1362,10 @@ out_aio_context:
static BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
const char *name,
BlockDriverState **pbs,
- AioContext **paio,
Error **errp)
{
BlockDriverState *bs;
BdrvDirtyBitmap *bitmap;
- AioContext *aio_context;
if (!node) {
error_setg(errp, "Node cannot be NULL");
@@ -1383,29 +1381,17 @@ static BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
return NULL;
}
- aio_context = bdrv_get_aio_context(bs);
- aio_context_acquire(aio_context);
-
bitmap = bdrv_find_dirty_bitmap(bs, name);
if (!bitmap) {
error_setg(errp, "Dirty bitmap '%s' not found", name);
- goto fail;
+ return NULL;
}
if (pbs) {
*pbs = bs;
}
- if (paio) {
- *paio = aio_context;
- } else {
- aio_context_release(aio_context);
- }
return bitmap;
-
- fail:
- aio_context_release(aio_context);
- return NULL;
}
/* New and old BlockDriverState structs for atomic group operations */
@@ -1791,7 +1777,7 @@ static void external_snapshot_commit(BlkActionState *common)
/* We don't need (or want) to use the transactional
* bdrv_reopen_multiple() across all the entries at once, because we
* don't want to abort all of them if one of them fails the reopen */
- if (!state->old_bs->copy_on_read) {
+ if (!atomic_read(&state->old_bs->copy_on_read)) {
bdrv_reopen(state->old_bs, state->old_bs->open_flags & ~BDRV_O_RDWR,
NULL);
}
@@ -2025,7 +2011,6 @@ static void block_dirty_bitmap_clear_prepare(BlkActionState *common,
state->bitmap = block_dirty_bitmap_lookup(action->node,
action->name,
&state->bs,
- &state->aio_context,
errp);
if (!state->bitmap) {
return;
@@ -2733,7 +2718,6 @@ void qmp_block_dirty_bitmap_add(const char *node, const char *name,
bool has_granularity, uint32_t granularity,
Error **errp)
{
- AioContext *aio_context;
BlockDriverState *bs;
if (!name || name[0] == '\0') {
@@ -2746,14 +2730,11 @@ void qmp_block_dirty_bitmap_add(const char *node, const char *name,
return;
}
- aio_context = bdrv_get_aio_context(bs);
- aio_context_acquire(aio_context);
-
if (has_granularity) {
if (granularity < 512 || !is_power_of_2(granularity)) {
error_setg(errp, "Granularity must be power of 2 "
"and at least 512");
- goto out;
+ return;
}
} else {
/* Default to cluster size, if available: */
@@ -2761,19 +2742,15 @@ void qmp_block_dirty_bitmap_add(const char *node, const char *name,
}
bdrv_create_dirty_bitmap(bs, granularity, name, errp);
-
- out:
- aio_context_release(aio_context);
}
void qmp_block_dirty_bitmap_remove(const char *node, const char *name,
Error **errp)
{
- AioContext *aio_context;
BlockDriverState *bs;
BdrvDirtyBitmap *bitmap;
- bitmap = block_dirty_bitmap_lookup(node, name, &bs, &aio_context, errp);
+ bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
if (!bitmap || !bs) {
return;
}
@@ -2782,13 +2759,10 @@ void qmp_block_dirty_bitmap_remove(const char *node, const char *name,
error_setg(errp,
"Bitmap '%s' is currently frozen and cannot be removed",
name);
- goto out;
+ return;
}
bdrv_dirty_bitmap_make_anon(bitmap);
bdrv_release_dirty_bitmap(bs, bitmap);
-
- out:
- aio_context_release(aio_context);
}
/**
@@ -2798,11 +2772,10 @@ void qmp_block_dirty_bitmap_remove(const char *node, const char *name,
void qmp_block_dirty_bitmap_clear(const char *node, const char *name,
Error **errp)
{
- AioContext *aio_context;
BdrvDirtyBitmap *bitmap;
BlockDriverState *bs;
- bitmap = block_dirty_bitmap_lookup(node, name, &bs, &aio_context, errp);
+ bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
if (!bitmap || !bs) {
return;
}
@@ -2811,18 +2784,15 @@ void qmp_block_dirty_bitmap_clear(const char *node, const char *name,
error_setg(errp,
"Bitmap '%s' is currently frozen and cannot be modified",
name);
- goto out;
+ return;
} else if (!bdrv_dirty_bitmap_enabled(bitmap)) {
error_setg(errp,
"Bitmap '%s' is currently disabled and cannot be cleared",
name);
- goto out;
+ return;
}
bdrv_clear_dirty_bitmap(bitmap, NULL);
-
- out:
- aio_context_release(aio_context);
}
void hmp_drive_del(Monitor *mon, const QDict *qdict)
diff --git a/include/block/accounting.h b/include/block/accounting.h
index 20891639d5..b833d26d6c 100644
--- a/include/block/accounting.h
+++ b/include/block/accounting.h
@@ -26,8 +26,10 @@
#define BLOCK_ACCOUNTING_H
#include "qemu/timed-average.h"
+#include "qemu/thread.h"
typedef struct BlockAcctTimedStats BlockAcctTimedStats;
+typedef struct BlockAcctStats BlockAcctStats;
enum BlockAcctType {
BLOCK_ACCT_READ,
@@ -37,12 +39,14 @@ enum BlockAcctType {
};
struct BlockAcctTimedStats {
+ BlockAcctStats *stats;
TimedAverage latency[BLOCK_MAX_IOTYPE];
unsigned interval_length; /* in seconds */
QSLIST_ENTRY(BlockAcctTimedStats) entries;
};
-typedef struct BlockAcctStats {
+struct BlockAcctStats {
+ QemuMutex lock;
uint64_t nr_bytes[BLOCK_MAX_IOTYPE];
uint64_t nr_ops[BLOCK_MAX_IOTYPE];
uint64_t invalid_ops[BLOCK_MAX_IOTYPE];
@@ -53,7 +57,7 @@ typedef struct BlockAcctStats {
QSLIST_HEAD(, BlockAcctTimedStats) intervals;
bool account_invalid;
bool account_failed;
-} BlockAcctStats;
+};
typedef struct BlockAcctCookie {
int64_t bytes;
@@ -61,7 +65,8 @@ typedef struct BlockAcctCookie {
enum BlockAcctType type;
} BlockAcctCookie;
-void block_acct_init(BlockAcctStats *stats, bool account_invalid,
+void block_acct_init(BlockAcctStats *stats);
+void block_acct_setup(BlockAcctStats *stats, bool account_invalid,
bool account_failed);
void block_acct_cleanup(BlockAcctStats *stats);
void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length);
diff --git a/include/block/block.h b/include/block/block.h
index 9b355e92d8..a4f09df95a 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -402,7 +402,8 @@ void bdrv_drain_all(void);
* block_job_defer_to_main_loop for how to do it). \
*/ \
assert(!bs_->wakeup); \
- bs_->wakeup = true; \
+ /* Set bs->wakeup before evaluating cond. */ \
+ atomic_mb_set(&bs_->wakeup, true); \
while (busy_) { \
if ((cond)) { \
waited_ = busy_ = true; \
@@ -414,7 +415,7 @@ void bdrv_drain_all(void);
waited_ |= busy_; \
} \
} \
- bs_->wakeup = false; \
+ atomic_set(&bs_->wakeup, false); \
} \
waited_; })
diff --git a/include/block/block_int.h b/include/block/block_int.h
index cb78c4fa82..748970055e 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -29,6 +29,7 @@
#include "qemu/option.h"
#include "qemu/queue.h"
#include "qemu/coroutine.h"
+#include "qemu/stats64.h"
#include "qemu/timer.h"
#include "qapi-types.h"
#include "qemu/hbitmap.h"
@@ -595,11 +596,6 @@ struct BlockDriverState {
/* Protected by AioContext lock */
- /* If true, copy read backing sectors into image. Can be >1 if more
- * than one client has requested copy-on-read.
- */
- int copy_on_read;
-
/* If we are reading a disk image, give its size in sectors.
* Generally read-only; it is written to by load_snapshot and
* save_snaphost, but the block layer is quiescent during those.
@@ -609,34 +605,57 @@ struct BlockDriverState {
/* Callback before write request is processed */
NotifierWithReturnList before_write_notifiers;
- /* number of in-flight requests; overall and serialising */
- unsigned int in_flight;
- unsigned int serialising_in_flight;
-
- bool wakeup;
-
- /* Offset after the highest byte written to */
- uint64_t wr_highest_offset;
-
/* threshold limit for writes, in bytes. "High water mark". */
uint64_t write_threshold_offset;
NotifierWithReturn write_threshold_notifier;
- /* counter for nested bdrv_io_plug */
- unsigned io_plugged;
-
- QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
- CoQueue flush_queue; /* Serializing flush queue */
- bool active_flush_req; /* Flush request in flight? */
- unsigned int write_gen; /* Current data generation */
- unsigned int flushed_gen; /* Flushed write generation */
-
+ /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
+ * Reading from the list can be done with either the BQL or the
+ * dirty_bitmap_mutex. Modifying a bitmap only requires
+ * dirty_bitmap_mutex. */
+ QemuMutex dirty_bitmap_mutex;
QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
+ /* Offset after the highest byte written to */
+ Stat64 wr_highest_offset;
+
+ /* If true, copy read backing sectors into image. Can be >1 if more
+ * than one client has requested copy-on-read. Accessed with atomic
+ * ops.
+ */
+ int copy_on_read;
+
+ /* number of in-flight requests; overall and serialising.
+ * Accessed with atomic ops.
+ */
+ unsigned int in_flight;
+ unsigned int serialising_in_flight;
+
+ /* Internal to BDRV_POLL_WHILE and bdrv_wakeup. Accessed with atomic
+ * ops.
+ */
+ bool wakeup;
+
+ /* counter for nested bdrv_io_plug.
+ * Accessed with atomic ops.
+ */
+ unsigned io_plugged;
+
/* do we need to tell the quest if we have a volatile write cache? */
int enable_write_cache;
+ /* Accessed with atomic ops. */
int quiesce_counter;
+ unsigned int write_gen; /* Current data generation */
+
+ /* Protected by reqs_lock. */
+ CoMutex reqs_lock;
+ QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
+ CoQueue flush_queue; /* Serializing flush queue */
+ bool active_flush_req; /* Flush request in flight? */
+
+ /* Only read/written by whoever has set active_flush_req to true. */
+ unsigned int flushed_gen; /* Flushed write generation */
};
struct BlockBackendRootState {
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 9dea14ba03..ad6558af56 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -36,8 +36,6 @@ bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap);
const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap);
int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap);
DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap);
-int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
- int64_t sector);
void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
int64_t cur_sector, int64_t nr_sectors);
void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
@@ -45,6 +43,9 @@ void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap, int64_t sector,
int nb_sectors);
+int bdrv_dirty_bitmap_get_meta_locked(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap, int64_t sector,
+ int nb_sectors);
void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap, int64_t sector,
int nb_sectors);
@@ -52,11 +53,6 @@ BdrvDirtyBitmapIter *bdrv_dirty_meta_iter_new(BdrvDirtyBitmap *bitmap);
BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap,
uint64_t first_sector);
void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter);
-int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter);
-void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *hbi, int64_t sector_num);
-int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap);
-int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap);
-void bdrv_dirty_bitmap_truncate(BlockDriverState *bs);
uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
uint64_t start, uint64_t count);
@@ -72,4 +68,19 @@ void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap,
bool finish);
void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap);
+/* Functions that require manual locking. */
+void bdrv_dirty_bitmap_lock(BdrvDirtyBitmap *bitmap);
+void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap);
+int bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+ int64_t sector);
+void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
+ int64_t cur_sector, int64_t nr_sectors);
+void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
+ int64_t cur_sector, int64_t nr_sectors);
+int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter);
+void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *hbi, int64_t sector_num);
+int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap);
+int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap);
+void bdrv_dirty_bitmap_truncate(BlockDriverState *bs);
+
#endif
diff --git a/include/qemu/stats64.h b/include/qemu/stats64.h
new file mode 100644
index 0000000000..4a357b3e9d
--- /dev/null
+++ b/include/qemu/stats64.h
@@ -0,0 +1,193 @@
+/*
+ * Atomic operations on 64-bit quantities.
+ *
+ * Copyright (C) 2017 Red Hat, Inc.
+ *
+ * Author: Paolo Bonzini <pbonzini@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_STATS64_H
+#define QEMU_STATS64_H 1
+
+#include "qemu/atomic.h"
+
+/* This provides atomic operations on 64-bit type, using a reader-writer
+ * spinlock on architectures that do not have 64-bit accesses. Even on
+ * those architectures, it tries hard not to take the lock.
+ */
+
+typedef struct Stat64 {
+#ifdef CONFIG_ATOMIC64
+ uint64_t value;
+#else
+ uint32_t low, high;
+ uint32_t lock;
+#endif
+} Stat64;
+
+#ifdef CONFIG_ATOMIC64
+static inline void stat64_init(Stat64 *s, uint64_t value)
+{
+ /* This is not guaranteed to be atomic! */
+ *s = (Stat64) { value };
+}
+
+static inline uint64_t stat64_get(const Stat64 *s)
+{
+ return atomic_read__nocheck(&s->value);
+}
+
+static inline void stat64_add(Stat64 *s, uint64_t value)
+{
+ atomic_add(&s->value, value);
+}
+
+static inline void stat64_min(Stat64 *s, uint64_t value)
+{
+ uint64_t orig = atomic_read__nocheck(&s->value);
+ while (orig > value) {
+ orig = atomic_cmpxchg__nocheck(&s->value, orig, value);
+ }
+}
+
+static inline void stat64_max(Stat64 *s, uint64_t value)
+{
+ uint64_t orig = atomic_read__nocheck(&s->value);
+ while (orig < value) {
+ orig = atomic_cmpxchg__nocheck(&s->value, orig, value);
+ }
+}
+#else
+uint64_t stat64_get(const Stat64 *s);
+bool stat64_min_slow(Stat64 *s, uint64_t value);
+bool stat64_max_slow(Stat64 *s, uint64_t value);
+bool stat64_add32_carry(Stat64 *s, uint32_t low, uint32_t high);
+
+static inline void stat64_init(Stat64 *s, uint64_t value)
+{
+ /* This is not guaranteed to be atomic! */
+ *s = (Stat64) { .low = value, .high = value >> 32, .lock = 0 };
+}
+
+static inline void stat64_add(Stat64 *s, uint64_t value)
+{
+ uint32_t low, high;
+ high = value >> 32;
+ low = (uint32_t) value;
+ if (!low) {
+ if (high) {
+ atomic_add(&s->high, high);
+ }
+ return;
+ }
+
+ for (;;) {
+ uint32_t orig = s->low;
+ uint32_t result = orig + low;
+ uint32_t old;
+
+ if (result < low || high) {
+ /* If the high part is affected, take the lock. */
+ if (stat64_add32_carry(s, low, high)) {
+ return;
+ }
+ continue;
+ }
+
+ /* No carry, try with a 32-bit cmpxchg. The result is independent of
+ * the high 32 bits, so it can race just fine with stat64_add32_carry
+ * and even stat64_get!
+ */
+ old = atomic_cmpxchg(&s->low, orig, result);
+ if (orig == old) {
+ return;
+ }
+ }
+}
+
+static inline void stat64_min(Stat64 *s, uint64_t value)
+{
+ uint32_t low, high;
+ uint32_t orig_low, orig_high;
+
+ high = value >> 32;
+ low = (uint32_t) value;
+ do {
+ orig_high = atomic_read(&s->high);
+ if (orig_high < high) {
+ return;
+ }
+
+ if (orig_high == high) {
+ /* High 32 bits are equal. Read low after high, otherwise we
+ * can get a false positive (e.g. 0x1235,0x0000 changes to
+ * 0x1234,0x8000 and we read it as 0x1234,0x0000). Pairs with
+ * the write barrier in stat64_min_slow.
+ */
+ smp_rmb();
+ orig_low = atomic_read(&s->low);
+ if (orig_low <= low) {
+ return;
+ }
+
+ /* See if we were lucky and a writer raced against us. The
+ * barrier is theoretically unnecessary, but if we remove it
+ * we may miss being lucky.
+ */
+ smp_rmb();
+ orig_high = atomic_read(&s->high);
+ if (orig_high < high) {
+ return;
+ }
+ }
+
+ /* If the value changes in any way, we have to take the lock. */
+ } while (!stat64_min_slow(s, value));
+}
+
+static inline void stat64_max(Stat64 *s, uint64_t value)
+{
+ uint32_t low, high;
+ uint32_t orig_low, orig_high;
+
+ high = value >> 32;
+ low = (uint32_t) value;
+ do {
+ orig_high = atomic_read(&s->high);
+ if (orig_high > high) {
+ return;
+ }
+
+ if (orig_high == high) {
+ /* High 32 bits are equal. Read low after high, otherwise we
+ * can get a false positive (e.g. 0x1234,0x8000 changes to
+ * 0x1235,0x0000 and we read it as 0x1235,0x8000). Pairs with
+ * the write barrier in stat64_max_slow.
+ */
+ smp_rmb();
+ orig_low = atomic_read(&s->low);
+ if (orig_low >= low) {
+ return;
+ }
+
+ /* See if we were lucky and a writer raced against us. The
+ * barrier is theoretically unnecessary, but if we remove it
+ * we may miss being lucky.
+ */
+ smp_rmb();
+ orig_high = atomic_read(&s->high);
+ if (orig_high > high) {
+ return;
+ }
+ }
+
+ /* If the value changes in any way, we have to take the lock. */
+ } while (!stat64_max_slow(s, value));
+}
+
+#endif
+
+#endif
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 840ad6134c..999eb2333a 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -72,15 +72,13 @@ typedef struct BlockDevOps {
* fields that must be public. This is in particular for QLIST_ENTRY() and
* friends so that BlockBackends can be kept in lists outside block-backend.c */
typedef struct BlockBackendPublic {
- /* I/O throttling has its own locking, but also some fields are
- * protected by the AioContext lock.
- */
-
- /* Protected by AioContext lock. */
+ /* throttled_reqs_lock protects the CoQueues for throttled requests. */
+ CoMutex throttled_reqs_lock;
CoQueue throttled_reqs[2];
/* Nonzero if the I/O limits are currently being ignored; generally
- * it is zero. */
+ * it is zero. Accessed with atomic operations.
+ */
unsigned int io_limits_disabled;
/* The following fields are protected by the ThrottleGroup lock.
diff --git a/migration/block.c b/migration/block.c
index 3aae5a375e..7674ae1078 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -341,10 +341,8 @@ static int set_dirty_tracking(void)
int ret;
QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
- aio_context_acquire(blk_get_aio_context(bmds->blk));
bmds->dirty_bitmap = bdrv_create_dirty_bitmap(blk_bs(bmds->blk),
BLOCK_SIZE, NULL, NULL);
- aio_context_release(blk_get_aio_context(bmds->blk));
if (!bmds->dirty_bitmap) {
ret = -errno;
goto fail;
@@ -355,9 +353,7 @@ static int set_dirty_tracking(void)
fail:
QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
if (bmds->dirty_bitmap) {
- aio_context_acquire(blk_get_aio_context(bmds->blk));
bdrv_release_dirty_bitmap(blk_bs(bmds->blk), bmds->dirty_bitmap);
- aio_context_release(blk_get_aio_context(bmds->blk));
}
}
return ret;
@@ -370,9 +366,7 @@ static void unset_dirty_tracking(void)
BlkMigDevState *bmds;
QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
- aio_context_acquire(blk_get_aio_context(bmds->blk));
bdrv_release_dirty_bitmap(blk_bs(bmds->blk), bmds->dirty_bitmap);
- aio_context_release(blk_get_aio_context(bmds->blk));
}
}
@@ -531,13 +525,16 @@ static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
} else {
blk_mig_unlock();
}
- if (bdrv_get_dirty(bs, bmds->dirty_bitmap, sector)) {
-
+ bdrv_dirty_bitmap_lock(bmds->dirty_bitmap);
+ if (bdrv_get_dirty_locked(bs, bmds->dirty_bitmap, sector)) {
if (total_sectors - sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
nr_sectors = total_sectors - sector;
} else {
nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
}
+ bdrv_reset_dirty_bitmap_locked(bmds->dirty_bitmap, sector, nr_sectors);
+ bdrv_dirty_bitmap_unlock(bmds->dirty_bitmap);
+
blk = g_new(BlkMigBlock, 1);
blk->buf = g_malloc(BLOCK_SIZE);
blk->bmds = bmds;
@@ -570,12 +567,12 @@ static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
g_free(blk);
}
- bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, sector, nr_sectors);
sector += nr_sectors;
bmds->cur_dirty = sector;
-
break;
}
+
+ bdrv_dirty_bitmap_unlock(bmds->dirty_bitmap);
sector += BDRV_SECTORS_PER_DIRTY_CHUNK;
bmds->cur_dirty = sector;
}
diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include
index 03eda37bf4..0ed8c3d323 100644
--- a/tests/docker/Makefile.include
+++ b/tests/docker/Makefile.include
@@ -126,7 +126,7 @@ docker-run: docker-qemu-src
" COPYING $(EXECUTABLE) to $(IMAGE)"))
$(call quiet-command, \
$(SRC_PATH)/tests/docker/docker.py run \
- -t \
+ $(if $(NOUSER),,-u $(shell id -u)) -t \
$(if $V,,--rm) \
$(if $(DEBUG),-i,--net=none) \
-e TARGET_LIST=$(TARGET_LIST) \
diff --git a/tests/docker/dockerfiles/centos6.docker b/tests/docker/dockerfiles/centos6.docker
index 34e0d3b91e..17a4d24d54 100644
--- a/tests/docker/dockerfiles/centos6.docker
+++ b/tests/docker/dockerfiles/centos6.docker
@@ -1,7 +1,7 @@
FROM centos:6
RUN yum install -y epel-release
ENV PACKAGES libfdt-devel ccache \
- tar git make gcc g++ \
+ tar git make gcc g++ flex bison \
zlib-devel glib2-devel SDL-devel pixman-devel \
epel-release
RUN yum install -y $PACKAGES
diff --git a/tests/docker/dockerfiles/fedora.docker b/tests/docker/dockerfiles/fedora.docker
index c4f80ad3d8..4eaa8ed2a5 100644
--- a/tests/docker/dockerfiles/fedora.docker
+++ b/tests/docker/dockerfiles/fedora.docker
@@ -1,8 +1,8 @@
FROM fedora:latest
ENV PACKAGES \
- ccache git tar PyYAML sparse flex bison python2 \
+ ccache git tar PyYAML sparse flex bison python2 bzip2 hostname \
glib2-devel pixman-devel zlib-devel SDL-devel libfdt-devel \
- gcc gcc-c++ clang make perl which bc findutils \
+ gcc gcc-c++ clang make perl which bc findutils libaio-devel \
mingw32-pixman mingw32-glib2 mingw32-gmp mingw32-SDL mingw32-pkg-config \
mingw32-gtk2 mingw32-gtk3 mingw32-gnutls mingw32-nettle mingw32-libtasn1 \
mingw32-libjpeg-turbo mingw32-libpng mingw32-curl mingw32-libssh2 \
diff --git a/util/Makefile.objs b/util/Makefile.objs
index c6205ebf86..8a333d3dd7 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -42,4 +42,5 @@ util-obj-y += log.o
util-obj-y += qdist.o
util-obj-y += qht.o
util-obj-y += range.o
+util-obj-y += stats64.o
util-obj-y += systemd.o
diff --git a/util/stats64.c b/util/stats64.c
new file mode 100644
index 0000000000..9968fcceac
--- /dev/null
+++ b/util/stats64.c
@@ -0,0 +1,137 @@
+/*
+ * Atomic operations on 64-bit quantities.
+ *
+ * Copyright (C) 2017 Red Hat, Inc.
+ *
+ * Author: Paolo Bonzini <pbonzini@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/atomic.h"
+#include "qemu/stats64.h"
+#include "qemu/processor.h"
+
+#ifndef CONFIG_ATOMIC64
+static inline void stat64_rdlock(Stat64 *s)
+{
+ /* Keep out incoming writers to avoid them starving us. */
+ atomic_add(&s->lock, 2);
+
+ /* If there is a concurrent writer, wait for it. */
+ while (atomic_read(&s->lock) & 1) {
+ cpu_relax();
+ }
+}
+
+static inline void stat64_rdunlock(Stat64 *s)
+{
+ atomic_sub(&s->lock, 2);
+}
+
+static inline bool stat64_wrtrylock(Stat64 *s)
+{
+ return atomic_cmpxchg(&s->lock, 0, 1) == 0;
+}
+
+static inline void stat64_wrunlock(Stat64 *s)
+{
+ atomic_dec(&s->lock);
+}
+
+uint64_t stat64_get(const Stat64 *s)
+{
+ uint32_t high, low;
+
+ stat64_rdlock((Stat64 *)s);
+
+ /* 64-bit writes always take the lock, so we can read in
+ * any order.
+ */
+ high = atomic_read(&s->high);
+ low = atomic_read(&s->low);
+ stat64_rdunlock((Stat64 *)s);
+
+ return ((uint64_t)high << 32) | low;
+}
+
+bool stat64_add32_carry(Stat64 *s, uint32_t low, uint32_t high)
+{
+ uint32_t old;
+
+ if (!stat64_wrtrylock(s)) {
+ cpu_relax();
+ return false;
+ }
+
+ /* 64-bit reads always take the lock, so they don't care about the
+ * order of our update. By updating s->low first, we can check
+ * whether we have to carry into s->high.
+ */
+ old = atomic_fetch_add(&s->low, low);
+ high += (old + low) < old;
+ atomic_add(&s->high, high);
+ stat64_wrunlock(s);
+ return true;
+}
+
+bool stat64_min_slow(Stat64 *s, uint64_t value)
+{
+ uint32_t high, low;
+ uint64_t orig;
+
+ if (!stat64_wrtrylock(s)) {
+ cpu_relax();
+ return false;
+ }
+
+ high = atomic_read(&s->high);
+ low = atomic_read(&s->low);
+
+ orig = ((uint64_t)high << 32) | low;
+ if (orig < value) {
+ /* We have to set low before high, just like stat64_min reads
+ * high before low. The value may become higher temporarily, but
+ * stat64_get does not notice (it takes the lock) and the only ill
+ * effect on stat64_min is that the slow path may be triggered
+ * unnecessarily.
+ */
+ atomic_set(&s->low, (uint32_t)value);
+ smp_wmb();
+ atomic_set(&s->high, value >> 32);
+ }
+ stat64_wrunlock(s);
+ return true;
+}
+
+bool stat64_max_slow(Stat64 *s, uint64_t value)
+{
+ uint32_t high, low;
+ uint64_t orig;
+
+ if (!stat64_wrtrylock(s)) {
+ cpu_relax();
+ return false;
+ }
+
+ high = atomic_read(&s->high);
+ low = atomic_read(&s->low);
+
+ orig = ((uint64_t)high << 32) | low;
+ if (orig > value) {
+ /* We have to set low before high, just like stat64_max reads
+ * high before low. The value may become lower temporarily, but
+ * stat64_get does not notice (it takes the lock) and the only ill
+ * effect on stat64_max is that the slow path may be triggered
+ * unnecessarily.
+ */
+ atomic_set(&s->low, (uint32_t)value);
+ smp_wmb();
+ atomic_set(&s->high, value >> 32);
+ }
+ stat64_wrunlock(s);
+ return true;
+}
+#endif