[PATCH 02/14] block: use return status of bdrv_append()

Vladimir Sementsov-Ogievskiy posted 14 patches 5 years, 5 months ago
There is a newer version of this series
[PATCH 02/14] block: use return status of bdrv_append()
Posted by Vladimir Sementsov-Ogievskiy 5 years, 5 months ago
Now bdrv_append returns status and we can drop all the local_err things
around it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block.c                     |  5 +----
 block/backup-top.c          | 20 ++++++++------------
 block/commit.c              |  5 +----
 block/mirror.c              |  6 ++----
 blockdev.c                  |  4 +---
 tests/test-bdrv-graph-mod.c |  6 +++---
 6 files changed, 16 insertions(+), 30 deletions(-)

diff --git a/block.c b/block.c
index 6d35449027..9b624b2535 100644
--- a/block.c
+++ b/block.c
@@ -3156,7 +3156,6 @@ static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
     int64_t total_size;
     QemuOpts *opts = NULL;
     BlockDriverState *bs_snapshot = NULL;
-    Error *local_err = NULL;
     int ret;
 
     /* if snapshot, we create a temporary backing file and open it
@@ -3203,9 +3202,7 @@ static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
      * order to be able to return one, we have to increase
      * bs_snapshot's refcount here */
     bdrv_ref(bs_snapshot);
-    bdrv_append(bs_snapshot, bs, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (bdrv_append(bs_snapshot, bs, errp) < 0) {
         bs_snapshot = NULL;
         goto out;
     }
diff --git a/block/backup-top.c b/block/backup-top.c
index af2f20f346..de9d5e1634 100644
--- a/block/backup-top.c
+++ b/block/backup-top.c
@@ -192,7 +192,7 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
                                          BlockCopyState **bcs,
                                          Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_GUARD();
     BDRVBackupTopState *state;
     BlockDriverState *top;
     bool appended = false;
@@ -225,9 +225,8 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
     bdrv_drained_begin(source);
 
     bdrv_ref(top);
-    bdrv_append(top, source, &local_err);
-    if (local_err) {
-        error_prepend(&local_err, "Cannot append backup-top filter: ");
+    if (bdrv_append(top, source, errp) < 0) {
+        error_prepend(errp, "Cannot append backup-top filter: ");
         goto fail;
     }
     appended = true;
@@ -237,18 +236,16 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
      * we want.
      */
     state->active = true;
-    bdrv_child_refresh_perms(top, top->backing, &local_err);
-    if (local_err) {
-        error_prepend(&local_err,
-                      "Cannot set permissions for backup-top filter: ");
+    if (bdrv_child_refresh_perms(top, top->backing, errp) < 0) {
+        error_prepend(errp, "Cannot set permissions for backup-top filter: ");
         goto fail;
     }
 
     state->cluster_size = cluster_size;
     state->bcs = block_copy_state_new(top->backing, state->target,
-                                      cluster_size, write_flags, &local_err);
-    if (local_err) {
-        error_prepend(&local_err, "Cannot create block-copy-state: ");
+                                      cluster_size, write_flags, errp);
+    if (!state->bcs) {
+        error_prepend(errp, "Cannot create block-copy-state: ");
         goto fail;
     }
     *bcs = state->bcs;
@@ -266,7 +263,6 @@ fail:
     }
 
     bdrv_drained_end(source);
-    error_propagate(errp, local_err);
 
     return NULL;
 }
diff --git a/block/commit.c b/block/commit.c
index 7732d02dfe..7720d4729b 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -253,7 +253,6 @@ void commit_start(const char *job_id, BlockDriverState *bs,
     CommitBlockJob *s;
     BlockDriverState *iter;
     BlockDriverState *commit_top_bs = NULL;
-    Error *local_err = NULL;
     int ret;
 
     assert(top != bs);
@@ -292,10 +291,8 @@ void commit_start(const char *job_id, BlockDriverState *bs,
 
     commit_top_bs->total_sectors = top->total_sectors;
 
-    bdrv_append(commit_top_bs, top, &local_err);
-    if (local_err) {
+    if (bdrv_append(commit_top_bs, top, errp) < 0) {
         commit_top_bs = NULL;
-        error_propagate(errp, local_err);
         goto fail;
     }
 
diff --git a/block/mirror.c b/block/mirror.c
index e8e8844afc..ca250f765d 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1557,7 +1557,6 @@ static BlockJob *mirror_start_job(
     BlockDriverState *mirror_top_bs;
     bool target_graph_mod;
     bool target_is_backing;
-    Error *local_err = NULL;
     int ret;
 
     if (granularity == 0) {
@@ -1606,12 +1605,11 @@ static BlockJob *mirror_start_job(
      * it alive until block_job_create() succeeds even if bs has no parent. */
     bdrv_ref(mirror_top_bs);
     bdrv_drained_begin(bs);
-    bdrv_append(mirror_top_bs, bs, &local_err);
+    ret = bdrv_append(mirror_top_bs, bs, errp);
     bdrv_drained_end(bs);
 
-    if (local_err) {
+    if (ret < 0) {
         bdrv_unref(mirror_top_bs);
-        error_propagate(errp, local_err);
         return NULL;
     }
 
diff --git a/blockdev.c b/blockdev.c
index 3848a9c8ab..36bef6b188 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1576,9 +1576,7 @@ static void external_snapshot_prepare(BlkActionState *common,
      * can fail, so we need to do it in .prepare; undoing it for abort is
      * always possible. */
     bdrv_ref(state->new_bs);
-    bdrv_append(state->new_bs, state->old_bs, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (bdrv_append(state->new_bs, state->old_bs, errp) < 0) {
         goto out;
     }
     state->overlay_appended = true;
diff --git a/tests/test-bdrv-graph-mod.c b/tests/test-bdrv-graph-mod.c
index 8cff13830e..2b71601c24 100644
--- a/tests/test-bdrv-graph-mod.c
+++ b/tests/test-bdrv-graph-mod.c
@@ -101,7 +101,7 @@ static BlockDriverState *pass_through_node(const char *name)
  */
 static void test_update_perm_tree(void)
 {
-    Error *local_err = NULL;
+    int ret;
 
     BlockBackend *root = blk_new(qemu_get_aio_context(),
                                  BLK_PERM_WRITE | BLK_PERM_CONSISTENT_READ,
@@ -114,8 +114,8 @@ static void test_update_perm_tree(void)
     bdrv_attach_child(filter, bs, "child", &child_of_bds,
                       BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, &error_abort);
 
-    bdrv_append(filter, bs, &local_err);
-    error_free_or_abort(&local_err);
+    ret = bdrv_append(filter, bs, NULL);
+    assert(ret < 0);
 
     blk_unref(root);
 }
-- 
2.21.3


Re: [PATCH 02/14] block: use return status of bdrv_append()
Posted by Greg Kurz 5 years, 5 months ago
On Wed,  9 Sep 2020 21:59:18 +0300
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> wrote:

> Now bdrv_append returns status and we can drop all the local_err things
> around it.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---

Reviewed-by: Greg Kurz <groug@kaod.org>

Just one suggestion for a follow-up below...

>  block.c                     |  5 +----
>  block/backup-top.c          | 20 ++++++++------------
>  block/commit.c              |  5 +----
>  block/mirror.c              |  6 ++----
>  blockdev.c                  |  4 +---
>  tests/test-bdrv-graph-mod.c |  6 +++---
>  6 files changed, 16 insertions(+), 30 deletions(-)
> 
> diff --git a/block.c b/block.c
> index 6d35449027..9b624b2535 100644
> --- a/block.c
> +++ b/block.c
> @@ -3156,7 +3156,6 @@ static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
>      int64_t total_size;
>      QemuOpts *opts = NULL;
>      BlockDriverState *bs_snapshot = NULL;
> -    Error *local_err = NULL;
>      int ret;
>  
>      /* if snapshot, we create a temporary backing file and open it
> @@ -3203,9 +3202,7 @@ static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
>       * order to be able to return one, we have to increase
>       * bs_snapshot's refcount here */
>      bdrv_ref(bs_snapshot);
> -    bdrv_append(bs_snapshot, bs, &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +    if (bdrv_append(bs_snapshot, bs, errp) < 0) {
>          bs_snapshot = NULL;
>          goto out;
>      }
> diff --git a/block/backup-top.c b/block/backup-top.c
> index af2f20f346..de9d5e1634 100644
> --- a/block/backup-top.c
> +++ b/block/backup-top.c
> @@ -192,7 +192,7 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
>                                           BlockCopyState **bcs,
>                                           Error **errp)
>  {
> -    Error *local_err = NULL;
> +    ERRP_GUARD();
>      BDRVBackupTopState *state;
>      BlockDriverState *top;
>      bool appended = false;
> @@ -225,9 +225,8 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
>      bdrv_drained_begin(source);
>  
>      bdrv_ref(top);
> -    bdrv_append(top, source, &local_err);
> -    if (local_err) {
> -        error_prepend(&local_err, "Cannot append backup-top filter: ");
> +    if (bdrv_append(top, source, errp) < 0) {
> +        error_prepend(errp, "Cannot append backup-top filter: ");
>          goto fail;
>      }
>      appended = true;
> @@ -237,18 +236,16 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
>       * we want.
>       */
>      state->active = true;
> -    bdrv_child_refresh_perms(top, top->backing, &local_err);
> -    if (local_err) {
> -        error_prepend(&local_err,
> -                      "Cannot set permissions for backup-top filter: ");
> +    if (bdrv_child_refresh_perms(top, top->backing, errp) < 0) {
> +        error_prepend(errp, "Cannot set permissions for backup-top filter: ");
>          goto fail;
>      }
>  
>      state->cluster_size = cluster_size;
>      state->bcs = block_copy_state_new(top->backing, state->target,
> -                                      cluster_size, write_flags, &local_err);
> -    if (local_err) {
> -        error_prepend(&local_err, "Cannot create block-copy-state: ");
> +                                      cluster_size, write_flags, errp);
> +    if (!state->bcs) {
> +        error_prepend(errp, "Cannot create block-copy-state: ");
>          goto fail;
>      }
>      *bcs = state->bcs;
> @@ -266,7 +263,6 @@ fail:
>      }
>  
>      bdrv_drained_end(source);
> -    error_propagate(errp, local_err);
>  
>      return NULL;
>  }
> diff --git a/block/commit.c b/block/commit.c
> index 7732d02dfe..7720d4729b 100644
> --- a/block/commit.c
> +++ b/block/commit.c
> @@ -253,7 +253,6 @@ void commit_start(const char *job_id, BlockDriverState *bs,
>      CommitBlockJob *s;
>      BlockDriverState *iter;
>      BlockDriverState *commit_top_bs = NULL;
> -    Error *local_err = NULL;
>      int ret;
>  

... this is unrelated but while reviewing I've noticed that the ret
variable isn't really needed.

>      assert(top != bs);
> @@ -292,10 +291,8 @@ void commit_start(const char *job_id, BlockDriverState *bs,
>  
>      commit_top_bs->total_sectors = top->total_sectors;
>  
> -    bdrv_append(commit_top_bs, top, &local_err);
> -    if (local_err) {
> +    if (bdrv_append(commit_top_bs, top, errp) < 0) {
>          commit_top_bs = NULL;
> -        error_propagate(errp, local_err);
>          goto fail;
>      }
>  
> diff --git a/block/mirror.c b/block/mirror.c
> index e8e8844afc..ca250f765d 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -1557,7 +1557,6 @@ static BlockJob *mirror_start_job(
>      BlockDriverState *mirror_top_bs;
>      bool target_graph_mod;
>      bool target_is_backing;
> -    Error *local_err = NULL;
>      int ret;
>  
>      if (granularity == 0) {
> @@ -1606,12 +1605,11 @@ static BlockJob *mirror_start_job(
>       * it alive until block_job_create() succeeds even if bs has no parent. */
>      bdrv_ref(mirror_top_bs);
>      bdrv_drained_begin(bs);
> -    bdrv_append(mirror_top_bs, bs, &local_err);
> +    ret = bdrv_append(mirror_top_bs, bs, errp);
>      bdrv_drained_end(bs);
>  
> -    if (local_err) {
> +    if (ret < 0) {
>          bdrv_unref(mirror_top_bs);
> -        error_propagate(errp, local_err);
>          return NULL;
>      }
>  
> diff --git a/blockdev.c b/blockdev.c
> index 3848a9c8ab..36bef6b188 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1576,9 +1576,7 @@ static void external_snapshot_prepare(BlkActionState *common,
>       * can fail, so we need to do it in .prepare; undoing it for abort is
>       * always possible. */
>      bdrv_ref(state->new_bs);
> -    bdrv_append(state->new_bs, state->old_bs, &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +    if (bdrv_append(state->new_bs, state->old_bs, errp) < 0) {
>          goto out;
>      }
>      state->overlay_appended = true;
> diff --git a/tests/test-bdrv-graph-mod.c b/tests/test-bdrv-graph-mod.c
> index 8cff13830e..2b71601c24 100644
> --- a/tests/test-bdrv-graph-mod.c
> +++ b/tests/test-bdrv-graph-mod.c
> @@ -101,7 +101,7 @@ static BlockDriverState *pass_through_node(const char *name)
>   */
>  static void test_update_perm_tree(void)
>  {
> -    Error *local_err = NULL;
> +    int ret;
>  
>      BlockBackend *root = blk_new(qemu_get_aio_context(),
>                                   BLK_PERM_WRITE | BLK_PERM_CONSISTENT_READ,
> @@ -114,8 +114,8 @@ static void test_update_perm_tree(void)
>      bdrv_attach_child(filter, bs, "child", &child_of_bds,
>                        BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, &error_abort);
>  
> -    bdrv_append(filter, bs, &local_err);
> -    error_free_or_abort(&local_err);
> +    ret = bdrv_append(filter, bs, NULL);
> +    assert(ret < 0);
>  
>      blk_unref(root);
>  }


Re: [PATCH 02/14] block: use return status of bdrv_append()
Posted by Vladimir Sementsov-Ogievskiy 5 years, 4 months ago
10.09.2020 19:10, Greg Kurz wrote:
> On Wed,  9 Sep 2020 21:59:18 +0300
> Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> wrote:
> 
>> Now bdrv_append returns status and we can drop all the local_err things
>> around it.
>>
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> ---
> 
> Reviewed-by: Greg Kurz <groug@kaod.org>
> 
> Just one suggestion for a follow-up below...
> 
>>   block.c                     |  5 +----
>>   block/backup-top.c          | 20 ++++++++------------

[..]

>> @@ -253,7 +253,6 @@ void commit_start(const char *job_id, BlockDriverState *bs,
>>       CommitBlockJob *s;
>>       BlockDriverState *iter;
>>       BlockDriverState *commit_top_bs = NULL;
>> -    Error *local_err = NULL;
>>       int ret;
>>   
> 
> ... this is unrelated but while reviewing I've noticed that the ret
> variable isn't really needed.
> 

Looking at this now, I'm not quite agreed. I think that avoiding multi-line if conditions is a good reason for additional variables, like this ret. A kind of taste of course, so if you want you may post a patch, but I don't want do it :)

-- 
Best regards,
Vladimir

Re: [PATCH 02/14] block: use return status of bdrv_append()
Posted by Alberto Garcia 5 years, 4 months ago
On Wed 09 Sep 2020 08:59:18 PM CEST, Vladimir Sementsov-Ogievskiy wrote:
> Now bdrv_append returns status and we can drop all the local_err things
> around it.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Reviewed-by: Alberto Garcia <berto@igalia.com>

Berto