From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
To: qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Emanuele Giuseppe Esposito <eesposit@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-devel@nongnu.org, Max Reitz <mreitz@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>, John Snow <jsnow@redhat.com>
Subject: [PATCH v2 7/7] block-copy: protect BlockCopyState .method fields
Date: Tue, 18 May 2021 12:07:57 +0200 [thread overview]
Message-ID: <20210518100757.31243-8-eesposit@redhat.com> (raw)
In-Reply-To: <20210518100757.31243-1-eesposit@redhat.com>
With tasks and calls lock protecting all State fields,
.method is the last BlockCopyState field left unprotected.
Set it as atomic.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block/block-copy.c | 37 ++++++++++++++++++-------------------
1 file changed, 18 insertions(+), 19 deletions(-)
diff --git a/block/block-copy.c b/block/block-copy.c
index 573e96fefb..ebccb7fbc6 100644
--- a/block/block-copy.c
+++ b/block/block-copy.c
@@ -108,7 +108,7 @@ typedef struct BlockCopyState {
/* State */
int64_t in_flight_bytes; /* protected by tasks_lock */
- BlockCopyMethod method;
+ BlockCopyMethod method; /* atomic */
CoMutex tasks_lock;
QLIST_HEAD(, BlockCopyTask) tasks; /* All tasks from all block-copy calls */
QemuMutex calls_lock;
@@ -184,7 +184,7 @@ static bool coroutine_fn block_copy_wait_one(BlockCopyState *s, int64_t offset,
static inline int64_t block_copy_chunk_size(BlockCopyState *s)
{
- switch (s->method) {
+ switch (qatomic_read(&s->method)) {
case COPY_READ_WRITE_CLUSTER:
return s->cluster_size;
case COPY_READ_WRITE:
@@ -338,16 +338,17 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
* buffered copying (read and write respect max_transfer on their
* behalf).
*/
- s->method = COPY_READ_WRITE_CLUSTER;
+ qatomic_set(&s->method, COPY_READ_WRITE_CLUSTER);
} else if (write_flags & BDRV_REQ_WRITE_COMPRESSED) {
/* Compression supports only cluster-size writes and no copy-range. */
- s->method = COPY_READ_WRITE_CLUSTER;
+ qatomic_set(&s->method, COPY_READ_WRITE_CLUSTER);
} else {
/*
* We enable copy-range, but keep small copy_size, until first
* successful copy_range (look at block_copy_do_copy).
*/
- s->method = use_copy_range ? COPY_RANGE_SMALL : COPY_READ_WRITE;
+ qatomic_set(&s->method, use_copy_range ? COPY_RANGE_SMALL :
+ COPY_READ_WRITE);
}
ratelimit_init(&s->rate_limit);
@@ -432,26 +433,24 @@ static int coroutine_fn block_copy_do_copy(BlockCopyState *s,
return ret;
}
- if (s->method >= COPY_RANGE_SMALL) {
+ if (qatomic_read(&s->method) >= COPY_RANGE_SMALL) {
ret = bdrv_co_copy_range(s->source, offset, s->target, offset, nbytes,
0, s->write_flags);
if (ret < 0) {
trace_block_copy_copy_range_fail(s, offset, ret);
- s->method = COPY_READ_WRITE;
+ qatomic_set(&s->method, COPY_READ_WRITE);
/* Fallback to read+write with allocated buffer */
} else {
- if (s->method == COPY_RANGE_SMALL) {
- /*
- * Successful copy-range. Now increase copy_size. copy_range
- * does not respect max_transfer (it's a TODO), so we factor
- * that in here.
- *
- * Note: we double-check s->method for the case when
- * parallel block-copy request unsets it during previous
- * bdrv_co_copy_range call.
- */
- s->method = COPY_RANGE_FULL;
- }
+ /*
+ * Successful copy-range. Now increase copy_size. copy_range
+ * does not respect max_transfer (it's a TODO), so we factor
+ * that in here.
+ *
+ * Note: we double-check s->method for the case when
+ * parallel block-copy request unsets it during previous
+ * bdrv_co_copy_range call.
+ */
+ qatomic_cmpxchg(&s->method, COPY_RANGE_SMALL, COPY_RANGE_FULL);
goto out;
}
}
--
2.30.2
next prev parent reply other threads:[~2021-05-18 10:32 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-18 10:07 [PATCH v2 0/7] block-copy: protect block-copy internal structures Emanuele Giuseppe Esposito
2021-05-18 10:07 ` [PATCH v2 1/7] block-copy: streamline choice of copy_range vs. read/write Emanuele Giuseppe Esposito
2021-05-20 14:42 ` Vladimir Sementsov-Ogievskiy
2021-05-20 15:06 ` Emanuele Giuseppe Esposito
2021-05-20 15:24 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:10 ` Paolo Bonzini
2021-05-21 15:48 ` Vladimir Sementsov-Ogievskiy
2021-05-21 16:43 ` Paolo Bonzini
2021-05-21 17:51 ` Vladimir Sementsov-Ogievskiy
2021-05-27 8:20 ` Stefan Hajnoczi
2021-05-27 19:04 ` Paolo Bonzini
2021-05-18 10:07 ` [PATCH v2 2/7] block-copy: improve documentation of BlockCopyTask and BlockCopyState types and functions Emanuele Giuseppe Esposito
2021-05-20 15:00 ` Vladimir Sementsov-Ogievskiy
2021-05-20 15:15 ` Emanuele Giuseppe Esposito
2021-05-18 10:07 ` [PATCH v2 3/7] block-copy: move progress_set_remaining in block_copy_task_end Emanuele Giuseppe Esposito
2021-05-20 15:03 ` Vladimir Sementsov-Ogievskiy
2021-05-18 10:07 ` [PATCH v2 4/7] block-copy: add a CoMutex to the BlockCopyTask list Emanuele Giuseppe Esposito
2021-05-20 15:19 ` Vladimir Sementsov-Ogievskiy
2021-05-25 10:07 ` Emanuele Giuseppe Esposito
2021-05-25 10:25 ` Vladimir Sementsov-Ogievskiy
2021-05-26 14:58 ` Paolo Bonzini
2021-05-26 16:13 ` Vladimir Sementsov-Ogievskiy
2021-05-27 9:07 ` Stefan Hajnoczi
2021-05-18 10:07 ` [PATCH v2 5/7] block-copy: add QemuMutex lock for BlockCopyCallState list Emanuele Giuseppe Esposito
2021-05-20 15:30 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:01 ` Paolo Bonzini
2021-05-25 10:58 ` Emanuele Giuseppe Esposito
2021-05-26 14:49 ` Paolo Bonzini
2021-05-28 10:53 ` Paolo Bonzini
2021-05-18 10:07 ` [PATCH v2 6/7] block-copy: atomic .cancelled and .finished fields in BlockCopyCallState Emanuele Giuseppe Esposito
2021-05-20 15:34 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:02 ` Paolo Bonzini
2021-05-21 15:53 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:56 ` Vladimir Sementsov-Ogievskiy
2021-05-21 16:47 ` Paolo Bonzini
2021-05-18 10:07 ` Emanuele Giuseppe Esposito [this message]
2021-05-21 17:10 ` [PATCH v2 7/7] block-copy: protect BlockCopyState .method fields Vladimir Sementsov-Ogievskiy
2021-05-25 10:18 ` Emanuele Giuseppe Esposito
2021-05-25 11:00 ` Vladimir Sementsov-Ogievskiy
2021-05-26 14:48 ` Paolo Bonzini
2021-05-26 17:18 ` Vladimir Sementsov-Ogievskiy
2021-05-28 10:24 ` Paolo Bonzini
2021-05-28 11:01 ` Paolo Bonzini
2021-05-28 11:52 ` Vladimir Sementsov-Ogievskiy
2021-05-28 12:44 ` Vladimir Sementsov-Ogievskiy
2021-05-20 13:47 ` [PATCH v2 0/7] block-copy: protect block-copy internal structures Vladimir Sementsov-Ogievskiy
2021-05-20 14:33 ` Emanuele Giuseppe Esposito
2021-05-27 10:31 ` Stefan Hajnoczi
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