diff --git a/block.c b/block.c
index d5ce8d39e423b7400bba6c5e92460d8a4ae797b3..8ce8b91f00cd0d33918b56637e9bc83da400ebc6 100644
--- a/block.c
+++ b/block.c
@@ -1803,8 +1803,11 @@ 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 1cc2e89c7cd01a62223cdbca5c4d5e47e12c71d6..e1b73d63ad3f651099e4479996f8515cbb929af2 100644
--- a/block/cow.c
+++ b/block/cow.c
@@ -189,7 +189,11 @@ static int coroutine_fn cow_read(BlockDriverState *bs, int64_t sector_num,
     int ret, n;
 
     while (nb_sectors > 0) {
-        if (bdrv_co_is_allocated(bs, sector_num, nb_sectors, &n)) {
+        ret = bdrv_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 3376901bd7b274c944ed88ec26873c6fc3ad61c6..7f7282e0c40a88de0b1d14d204ca2164dc94ea94 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -648,13 +648,11 @@ 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) || (ret == QCOW2_CLUSTER_ZERO);
diff --git a/block/stream.c b/block/stream.c
index 7fe9e486bf3f9c6b2b2c08669dd23b4c29709206..4e8d177fdc1b0e0278d8327a1c553991ce308a12 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -120,7 +120,7 @@ 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_co_is_allocated_above(bs->backing_hd, base,
diff --git a/qemu-img.c b/qemu-img.c
index b9a848db74de8c77e8a009669ac72fe048bc71cc..b01998b04909caa19dce40a209b09f370d20283d 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1485,8 +1485,15 @@ 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;
                     }
@@ -2076,6 +2083,11 @@ 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-cmds.c b/qemu-io-cmds.c
index ffbcf31cfc6389e7b615bfc9529dc3e9629220f8..ffe48adfba953109dc47ed2ec4e836cc6caf0a42 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -1829,6 +1829,10 @@ static int alloc_f(BlockDriverState *bs, 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) {