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authorFam Zheng <famz@redhat.com>2015-12-01 17:36:28 +0800
committerStefan Hajnoczi <stefanha@redhat.com>2015-12-03 11:08:07 +0800
commit61408b250eaa6157e49fbdcfe21f2f53e50b9277 (patch)
tree78f39e253a091ed8e5303f0c13fa89a0f231c60c
parentd21e8776f6578be155714ae95c7d6c1bb03e8e34 (diff)
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block: Don't wait serialising for non-COR read requests
The assertion problem was noticed in 06c3916b35a, but it wasn't completely fixed, because even though the req is not marked as serialising, it still gets serialised by wait_serialising_requests against other serialising requests, which could lead to the same assertion failure. Fix it by even more explicitly skipping the serialising for this specific case. Signed-off-by: Fam Zheng <famz@redhat.com> Message-id: 1448962590-2842-2-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-rw-r--r--block/backup.c2
-rw-r--r--block/io.c12
-rw-r--r--include/block/block.h4
-rw-r--r--trace-events2
4 files changed, 11 insertions, 9 deletions
diff --git a/block/backup.c b/block/backup.c
index 3b3911925..705bb7766 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -132,7 +132,7 @@ static int coroutine_fn backup_do_cow(BlockDriverState *bs,
qemu_iovec_init_external(&bounce_qiov, &iov, 1);
if (is_write_notifier) {
- ret = bdrv_co_no_copy_on_readv(bs,
+ ret = bdrv_co_readv_no_serialising(bs,
start * BACKUP_SECTORS_PER_CLUSTER,
n, &bounce_qiov);
} else {
diff --git a/block/io.c b/block/io.c
index adc1eabef..e00fb5d69 100644
--- a/block/io.c
+++ b/block/io.c
@@ -863,7 +863,9 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
mark_request_serialising(req, bdrv_get_cluster_size(bs));
}
- wait_serialising_requests(req);
+ if (!(flags & BDRV_REQ_NO_SERIALISING)) {
+ wait_serialising_requests(req);
+ }
if (flags & BDRV_REQ_COPY_ON_READ) {
int pnum;
@@ -952,7 +954,7 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
}
/* Don't do copy-on-read if we read data before write operation */
- if (bs->copy_on_read && !(flags & BDRV_REQ_NO_COPY_ON_READ)) {
+ if (bs->copy_on_read && !(flags & BDRV_REQ_NO_SERIALISING)) {
flags |= BDRV_REQ_COPY_ON_READ;
}
@@ -1021,13 +1023,13 @@ int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0);
}
-int coroutine_fn bdrv_co_no_copy_on_readv(BlockDriverState *bs,
+int coroutine_fn bdrv_co_readv_no_serialising(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
- trace_bdrv_co_no_copy_on_readv(bs, sector_num, nb_sectors);
+ trace_bdrv_co_readv_no_serialising(bs, sector_num, nb_sectors);
return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov,
- BDRV_REQ_NO_COPY_ON_READ);
+ BDRV_REQ_NO_SERIALISING);
}
int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
diff --git a/include/block/block.h b/include/block/block.h
index 73edb1a79..347732873 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -61,7 +61,7 @@ typedef enum {
* opened with BDRV_O_UNMAP.
*/
BDRV_REQ_MAY_UNMAP = 0x4,
- BDRV_REQ_NO_COPY_ON_READ = 0x8,
+ BDRV_REQ_NO_SERIALISING = 0x8,
} BdrvRequestFlags;
typedef struct BlockSizes {
@@ -248,7 +248,7 @@ int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov);
int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
-int coroutine_fn bdrv_co_no_copy_on_readv(BlockDriverState *bs,
+int coroutine_fn bdrv_co_readv_no_serialising(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov);
diff --git a/trace-events b/trace-events
index 0b0ff0244..2fce98e76 100644
--- a/trace-events
+++ b/trace-events
@@ -69,7 +69,7 @@ bdrv_aio_write_zeroes(void *bs, int64_t sector_num, int nb_sectors, int flags, v
bdrv_lock_medium(void *bs, bool locked) "bs %p locked %d"
bdrv_co_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
bdrv_co_copy_on_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
-bdrv_co_no_copy_on_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
+bdrv_co_readv_no_serialising(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
bdrv_co_writev(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
bdrv_co_write_zeroes(void *bs, int64_t sector_num, int nb_sector, int flags) "bs %p sector_num %"PRId64" nb_sectors %d flags %#x"
bdrv_co_io_em(void *bs, int64_t sector_num, int nb_sectors, int is_write, void *acb) "bs %p sector_num %"PRId64" nb_sectors %d is_write %d acb %p"