This will help to identify how many of the user-issued discard operations (accounted on a device level) have actually suceeded down on the host file (even though the numbers will not be exactly the same if non-raw format driver is used (e.g. qcow2 sending metadata discards)).
Note that these numbers will not include discards triggered by write-zeroes + MAY_UNMAP calls. Signed-off-by: Anton Nefedov <anton.nefe...@virtuozzo.com> --- block/file-posix.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 2da3a76355..1a7126046c 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -163,6 +163,11 @@ typedef struct BDRVRawState { bool has_fallocate; bool needs_alignment; bool check_cache_dropped; + struct { + int64_t discard_nb_ok; + int64_t discard_nb_failed; + int64_t discard_bytes_ok; + } stats; PRManager *pr_mgr; } BDRVRawState; @@ -2582,12 +2587,25 @@ static void coroutine_fn raw_co_invalidate_cache(BlockDriverState *bs, #endif /* !__linux__ */ } +static void raw_account_discard(BDRVRawState *s, uint64_t nbytes, int ret) +{ + if (ret) { + s->stats.discard_nb_failed++; + } else { + s->stats.discard_nb_ok++; + s->stats.discard_bytes_ok += nbytes; + } +} + static coroutine_fn int raw_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes) { BDRVRawState *s = bs->opaque; + int ret; - return paio_submit_co(bs, s->fd, offset, NULL, bytes, QEMU_AIO_DISCARD); + ret = paio_submit_co(bs, s->fd, offset, NULL, bytes, QEMU_AIO_DISCARD); + raw_account_discard(s, bytes, ret); + return ret; } static int coroutine_fn raw_co_pwrite_zeroes( @@ -3084,10 +3102,14 @@ hdev_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes) ret = fd_open(bs); if (ret < 0) { + raw_account_discard(s, bytes, ret); return ret; } - return paio_submit_co(bs, s->fd, offset, NULL, bytes, - QEMU_AIO_DISCARD | QEMU_AIO_BLKDEV); + + ret = paio_submit_co(bs, s->fd, offset, NULL, bytes, + QEMU_AIO_DISCARD | QEMU_AIO_BLKDEV); + raw_account_discard(s, bytes, ret); + return ret; } static coroutine_fn int hdev_co_pwrite_zeroes(BlockDriverState *bs, -- 2.17.1