From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, armbru@redhat.com, berto@igalia.com,
vsementsov@virtuozzo.com, eblake@redhat.com, jsnow@redhat.com,
stefanha@redhat.com, pbonzini@redhat.com,
pavel.dovgaluk@ispras.ru, ari@tuxera.com, mreitz@redhat.com,
kwolf@redhat.com, den@openvz.org, Greg Kurz <groug@kaod.org>
Subject: [PATCH v3 01/13] block: return status from bdrv_append and friends
Date: Fri, 16 Oct 2020 20:10:45 +0300 [thread overview]
Message-ID: <20201016171057.6182-2-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20201016171057.6182-1-vsementsov@virtuozzo.com>
The recommended use of qemu error api assumes returning status together
with setting errp and avoid void functions with errp parameter. Let's
improve bdrv_append and some friends to reduce error-propagation
overhead in further patches.
Choose int return status, because bdrv_replace_node() has call to
bdrv_check_update_perm(), which reports int status, which seems correct
to propagate.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
include/block/block.h | 12 ++++++------
block.c | 39 ++++++++++++++++++++++++---------------
2 files changed, 30 insertions(+), 21 deletions(-)
diff --git a/include/block/block.h b/include/block/block.h
index d16c401cb4..afb29cdbe4 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -346,10 +346,10 @@ int bdrv_create(BlockDriver *drv, const char* filename,
int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
BlockDriverState *bdrv_new(void);
-void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
- Error **errp);
-void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
- Error **errp);
+int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
+ Error **errp);
+int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
+ Error **errp);
int bdrv_parse_aio(const char *mode, int *flags);
int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
@@ -361,8 +361,8 @@ BdrvChild *bdrv_open_child(const char *filename,
BdrvChildRole child_role,
bool allow_none, Error **errp);
BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
-void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
- Error **errp);
+int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
+ Error **errp);
int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
const char *bdref_key, Error **errp);
BlockDriverState *bdrv_open(const char *filename, const char *reference,
diff --git a/block.c b/block.c
index 430edf79bb..b05fbff42d 100644
--- a/block.c
+++ b/block.c
@@ -2870,14 +2870,15 @@ static BdrvChildRole bdrv_backing_role(BlockDriverState *bs)
* Sets the bs->backing link of a BDS. A new reference is created; callers
* which don't need their own reference any more must call bdrv_unref().
*/
-void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
+int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
Error **errp)
{
+ int ret = 0;
bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) &&
bdrv_inherits_from_recursive(backing_hd, bs);
if (bdrv_is_backing_chain_frozen(bs, child_bs(bs->backing), errp)) {
- return;
+ return -EPERM;
}
if (backing_hd) {
@@ -2896,15 +2897,22 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_of_bds,
bdrv_backing_role(bs), errp);
+ if (!bs->backing) {
+ ret = -EINVAL;
+ goto out;
+ }
+
/* If backing_hd was already part of bs's backing chain, and
* inherits_from pointed recursively to bs then let's update it to
* point directly to bs (else it will become NULL). */
- if (bs->backing && update_inherits_from) {
+ if (update_inherits_from) {
backing_hd->inherits_from = bs;
}
out:
bdrv_refresh_limits(bs, NULL);
+
+ return ret;
}
/*
@@ -4554,8 +4562,8 @@ static bool should_update_child(BdrvChild *c, BlockDriverState *to)
return ret;
}
-void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
- Error **errp)
+int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
+ Error **errp)
{
BdrvChild *c, *next;
GSList *list = NULL, *p;
@@ -4577,6 +4585,7 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
continue;
}
if (c->frozen) {
+ ret = -EPERM;
error_setg(errp, "Cannot change '%s' link to '%s'",
c->name, from->node_name);
goto out;
@@ -4612,6 +4621,8 @@ out:
g_slist_free(list);
bdrv_drained_end(from);
bdrv_unref(from);
+
+ return ret;
}
/*
@@ -4630,20 +4641,16 @@ out:
* parents of bs_top after bdrv_append() returns. If the caller needs to keep a
* reference of its own, it must call bdrv_ref().
*/
-void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
- Error **errp)
+int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
+ Error **errp)
{
- Error *local_err = NULL;
-
- bdrv_set_backing_hd(bs_new, bs_top, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
+ int ret = bdrv_set_backing_hd(bs_new, bs_top, errp);
+ if (ret < 0) {
goto out;
}
- bdrv_replace_node(bs_top, bs_new, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
+ ret = bdrv_replace_node(bs_top, bs_new, errp);
+ if (ret < 0) {
bdrv_set_backing_hd(bs_new, NULL, &error_abort);
goto out;
}
@@ -4652,6 +4659,8 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
* additional reference any more. */
out:
bdrv_unref(bs_new);
+
+ return ret;
}
static void bdrv_delete(BlockDriverState *bs)
--
2.21.3
next prev parent reply other threads:[~2020-10-16 17:18 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-16 17:10 [PATCH v3 00/13] block: deal with errp: part I Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` Vladimir Sementsov-Ogievskiy [this message]
2020-10-19 11:50 ` [PATCH v3 01/13] block: return status from bdrv_append and friends Kevin Wolf
2020-10-16 17:10 ` [PATCH v3 02/13] block: use return status of bdrv_append() Vladimir Sementsov-Ogievskiy
2020-10-19 12:13 ` Kevin Wolf
2020-10-19 15:45 ` Markus Armbruster
2020-10-19 16:10 ` Kevin Wolf
2020-10-16 17:10 ` [PATCH v3 03/13] block: check return value of bdrv_open_child and drop error propagation Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 04/13] blockdev: fix drive_backup_prepare() missed error Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 05/13] block: drop extra error propagation for bdrv_set_backing_hd Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 06/13] block/mirror: drop extra error propagation in commit_active_start() Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 07/13] blockjob: return status from block_job_set_speed() Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 08/13] block/qcow2: qcow2_get_specific_info(): drop error propagation Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 09/13] block/qcow2-bitmap: improve qcow2_load_dirty_bitmaps() interface Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 10/13] block/qcow2-bitmap: return status from qcow2_store_persistent_dirty_bitmaps Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 11/13] block/qcow2: read_cache_sizes: return status value Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 12/13] block/qcow2: simplify qcow2_co_invalidate_cache() Vladimir Sementsov-Ogievskiy
2020-10-19 13:06 ` Kevin Wolf
2020-10-20 12:46 ` Vladimir Sementsov-Ogievskiy
2020-10-16 17:10 ` [PATCH v3 13/13] block/qed: bdrv_qed_do_open: deal with errp Vladimir Sementsov-Ogievskiy
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