From a57a8dac1d14774b6173c9a4d08af42cb3111dd2 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Paolo Bonzini Date: Fri, 6 Sep 2013 18:12:34 +0200 Subject: [PATCH 14/25] block: expect errors from bdrv_co_is_allocated Some bdrv_is_allocated callers do not expect errors, but the fallback in qcow2.c might make other callers trip on assertion failures or infinite loops. Fix the callers to always look for errors. Cc: qemu-stable@nongnu.org Reviewed-by: Eric Blake Signed-off-by: Paolo Bonzini Signed-off-by: Stefan Hajnoczi (cherry picked from commit d663640c04f2aab810915c556390211d75457704) [RHEL: in block/stream.o avoid a "'copy' may be used uninitialized" warning due to the older compiler] Signed-off-by: Michal Novotny --- block.c | 7 +++++-- block/cow.c | 6 +++++- block/qcow2.c | 4 +--- block/stream.c | 4 +++- qemu-img.c | 16 ++++++++++++++-- qemu-io.c | 4 ++++ 6 files changed, 32 insertions(+), 9 deletions(-) diff --git a/block.c b/block.c index ba20499..421aae3 100644 --- a/block.c +++ b/block.c @@ -1477,8 +1477,11 @@ int bdrv_commit(BlockDriverState *bs) buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE); for (sector = 0; sector < total_sectors; sector += n) { - if (bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) { - + ret = bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n); + if (ret < 0) { + goto ro_cleanup; + } + if (ret) { if (bdrv_read(bs, sector, buf, n) != 0) { ret = -EIO; goto ro_cleanup; diff --git a/block/cow.c b/block/cow.c index be86a62..d5cac88 100644 --- a/block/cow.c +++ b/block/cow.c @@ -212,7 +212,11 @@ static int coroutine_fn cow_read(BlockDriverState *bs, int64_t sector_num, int ret, n; while (nb_sectors > 0) { - if (cow_co_is_allocated(bs, sector_num, nb_sectors, &n)) { + ret = cow_co_is_allocated(bs, sector_num, nb_sectors, &n); + if (ret < 0) { + return ret; + } + if (ret) { ret = bdrv_pread(bs->file, s->cow_sectors_offset + sector_num * 512, buf, n * 512); diff --git a/block/qcow2.c b/block/qcow2.c index 9a1665d..d102440 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -385,13 +385,11 @@ static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs, int ret; *pnum = nb_sectors; - /* FIXME We can get errors here, but the bdrv_co_is_allocated interface - * can't pass them on today */ qemu_co_mutex_lock(&s->lock); ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset); qemu_co_mutex_unlock(&s->lock); if (ret < 0) { - *pnum = 0; + return ret; } return (cluster_offset != 0); diff --git a/block/stream.c b/block/stream.c index 21542e3..619038a 100644 --- a/block/stream.c +++ b/block/stream.c @@ -144,7 +144,7 @@ wait: if (ret == 1) { /* Allocated in the top, no need to copy. */ copy = false; - } else { + } else if (ret >= 0) { /* Copy if allocated in the intermediate images. Limit to the * known-unallocated area [sector_num, sector_num+n). */ ret = bdrv_is_allocated_above(bs->backing_hd, base, @@ -156,6 +156,8 @@ wait: } copy = (ret == 1); + } else { + copy = false; } trace_stream_one_iteration(s, sector_num, n, ret); if (ret >= 0 && copy) { diff --git a/qemu-img.c b/qemu-img.c index 30a9313..bfc2ff3 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1132,8 +1132,15 @@ static int img_convert(int argc, char **argv) are present in both the output's and input's base images (no need to copy them). */ if (out_baseimg) { - if (!bdrv_is_allocated(bs[bs_i], sector_num - bs_offset, - n, &n1)) { + ret = bdrv_is_allocated(bs[bs_i], sector_num - bs_offset, + n, &n1); + if (ret < 0) { + error_report("error while reading metadata for sector " + "%" PRId64 ": %s", + sector_num - bs_offset, strerror(-ret)); + goto out; + } + if (!ret) { sector_num += n1; continue; } @@ -1585,6 +1592,11 @@ static int img_rebase(int argc, char **argv) /* If the cluster is allocated, we don't need to take action */ ret = bdrv_is_allocated(bs, sector, n, &n); + if (ret < 0) { + error_report("error while reading image metadata: %s", + strerror(-ret)); + goto out; + } if (ret) { continue; } diff --git a/qemu-io.c b/qemu-io.c index 0a55cfe..df1ed94 100644 --- a/qemu-io.c +++ b/qemu-io.c @@ -1302,6 +1302,10 @@ static int alloc_f(int argc, char **argv) sector_num = offset >> 9; while (remaining) { ret = bdrv_is_allocated(bs, sector_num, remaining, &num); + if (ret < 0) { + printf("is_allocated failed: %s\n", strerror(-ret)); + return 0; + } sector_num += num; remaining -= num; if (ret) { -- 1.7.11.7