Merge remote-tracking branch 'remotes/cody/tags/block-pull-request' into staging
# gpg: Signature made Fri 14 Aug 2015 14:54:27 BST using RSA key ID C0DE3057
# gpg: Good signature from "Jeffrey Cody <jcody@redhat.com>"
# gpg: aka "Jeffrey Cody <jeff@codyprime.org>"
# gpg: aka "Jeffrey Cody <codyprime@gmail.com>"
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# Primary key fingerprint: 9957 4B4D 3474 90E7 9D98 D624 BDBE 7B27 C0DE 3057
* remotes/cody/tags/block-pull-request:
mirror: Fix coroutine reentrance
block/mirror: limit qiov to IOV_MAX elements
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/block/mirror.c b/block/mirror.c
index fc4d8f5..9474443 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -60,6 +60,7 @@
int sectors_in_flight;
int ret;
bool unmap;
+ bool waiting_for_io;
} MirrorBlockJob;
typedef struct MirrorOp {
@@ -114,11 +115,7 @@
qemu_iovec_destroy(&op->qiov);
g_slice_free(MirrorOp, op);
- /* Enter coroutine when it is not sleeping. The coroutine sleeps to
- * rate-limit itself. The coroutine will eventually resume since there is
- * a sleep timeout so don't wake it early.
- */
- if (s->common.busy) {
+ if (s->waiting_for_io) {
qemu_coroutine_enter(s->common.co, NULL);
}
}
@@ -203,7 +200,9 @@
/* Wait for I/O to this cluster (from a previous iteration) to be done. */
while (test_bit(next_chunk, s->in_flight_bitmap)) {
trace_mirror_yield_in_flight(s, sector_num, s->in_flight);
+ s->waiting_for_io = true;
qemu_coroutine_yield();
+ s->waiting_for_io = false;
}
do {
@@ -239,12 +238,18 @@
*/
while (nb_chunks == 0 && s->buf_free_count < added_chunks) {
trace_mirror_yield_buf_busy(s, nb_chunks, s->in_flight);
+ s->waiting_for_io = true;
qemu_coroutine_yield();
+ s->waiting_for_io = false;
}
if (s->buf_free_count < nb_chunks + added_chunks) {
trace_mirror_break_buf_busy(s, nb_chunks, s->in_flight);
break;
}
+ if (IOV_MAX < nb_chunks + added_chunks) {
+ trace_mirror_break_iov_max(s, nb_chunks, added_chunks);
+ break;
+ }
/* We have enough free space to copy these sectors. */
bitmap_set(s->in_flight_bitmap, next_chunk, added_chunks);
@@ -333,7 +338,9 @@
static void mirror_drain(MirrorBlockJob *s)
{
while (s->in_flight > 0) {
+ s->waiting_for_io = true;
qemu_coroutine_yield();
+ s->waiting_for_io = false;
}
}
@@ -506,7 +513,9 @@
if (s->in_flight == MAX_IN_FLIGHT || s->buf_free_count == 0 ||
(cnt == 0 && s->in_flight > 0)) {
trace_mirror_yield(s, s->in_flight, s->buf_free_count, cnt);
+ s->waiting_for_io = true;
qemu_coroutine_yield();
+ s->waiting_for_io = false;
continue;
} else if (cnt != 0) {
delay_ns = mirror_iteration(s);
diff --git a/trace-events b/trace-events
index 94bf3bb..8f9614a 100644
--- a/trace-events
+++ b/trace-events
@@ -94,6 +94,7 @@
mirror_yield_in_flight(void *s, int64_t sector_num, int in_flight) "s %p sector_num %"PRId64" in_flight %d"
mirror_yield_buf_busy(void *s, int nb_chunks, int in_flight) "s %p requested chunks %d in_flight %d"
mirror_break_buf_busy(void *s, int nb_chunks, int in_flight) "s %p requested chunks %d in_flight %d"
+mirror_break_iov_max(void *s, int nb_chunks, int added_chunks) "s %p requested chunks %d added_chunks %d"
# block/backup.c
backup_do_cow_enter(void *job, int64_t start, int64_t sector_num, int nb_sectors) "job %p start %"PRId64" sector_num %"PRId64" nb_sectors %d"
