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authorVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>2020-10-21 17:58:44 +0300
committerMax Reitz <mreitz@redhat.com>2020-12-18 12:35:55 +0100
commitd1a764d126aa9bd1b519855607f55daf266b07bf (patch)
treea38cf66506446cbde41fe5aefa6f1979ac5901f2 /block/io.c
parent8ac5aab255d5c55d21bb33f4f6dd6dc58319e512 (diff)
block: introduce BDRV_REQ_NO_WAIT flag
Add flag to make serialising request no wait: if there are conflicting requests, just return error immediately. It's will be used in upcoming preallocate filter. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20201021145859.11201-7-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block/io.c')
-rw-r--r--block/io.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/block/io.c b/block/io.c
index fadfed3ab8..95b1c56c06 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1858,9 +1858,18 @@ bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, uint64_t bytes,
assert(!(bs->open_flags & BDRV_O_INACTIVE));
assert((bs->open_flags & BDRV_O_NO_IO) == 0);
assert(!(flags & ~BDRV_REQ_MASK));
+ assert(!((flags & BDRV_REQ_NO_WAIT) && !(flags & BDRV_REQ_SERIALISING)));
if (flags & BDRV_REQ_SERIALISING) {
- bdrv_make_request_serialising(req, bdrv_get_cluster_size(bs));
+ QEMU_LOCK_GUARD(&bs->reqs_lock);
+
+ tracked_request_set_serialising(req, bdrv_get_cluster_size(bs));
+
+ if ((flags & BDRV_REQ_NO_WAIT) && bdrv_find_conflicting_request(req)) {
+ return -EBUSY;
+ }
+
+ bdrv_wait_serialising_requests_locked(req);
} else {
bdrv_wait_serialising_requests(req);
}