[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH for-3.1? 1/3] block: Always abort reopen after prepa
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH for-3.1? 1/3] block: Always abort reopen after prepare succeeded |
Date: |
Fri, 16 Nov 2018 16:53:00 +0100 |
bdrv_reopen_multiple() does not invoke bdrv_reopen_abort() for the
element of the reopen queue for which bdrv_reopen_prepare() failed,
because it assumes that the prepare function will have rolled back all
changes already.
However, bdrv_reopen_prepare() does not do this in every case: It may
notice an error after BlockDriver.bdrv_reopen_prepare() succeeded, and
it will not invoke BlockDriver.bdrv_reopen_abort() then; and neither
will bdrv_reopen_multiple(), as explained above.
This is wrong because we must always call .bdrv_reopen_commit() or
.bdrv_reopen_abort() after .bdrv_reopen_prepare() has succeeded.
Otherwise, the block driver has no chance to undo what it has done in
its implementation of .bdrv_reopen_prepare().
To fix this, bdrv_reopen_prepare() has to call .bdrv_reopen_abort() if
it wants to return an error after .bdrv_reopen_prepare() has succeeded.
Signed-off-by: Max Reitz <address@hidden>
---
block.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/block.c b/block.c
index fd67e14dfa..7f5859aa74 100644
--- a/block.c
+++ b/block.c
@@ -3332,7 +3332,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue,
if (!qobject_is_equal(new, old)) {
error_setg(errp, "Cannot change the option '%s'", entry->key);
ret = -EINVAL;
- goto error;
+ goto late_error;
}
} while ((entry = qdict_next(reopen_state->options, entry)));
}
@@ -3340,7 +3340,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue,
ret = bdrv_check_perm(reopen_state->bs, queue, reopen_state->perm,
reopen_state->shared_perm, NULL, errp);
if (ret < 0) {
- goto error;
+ goto late_error;
}
ret = 0;
@@ -3354,6 +3354,19 @@ error:
qobject_unref(orig_reopen_opts);
g_free(discard);
return ret;
+
+late_error:
+ /* drv->bdrv_reopen_prepare() has succeeded, so we need to call
+ * drv->bdrv_reopen_abort() before signaling an error
+ * (bdrv_reopen_multiple() will not call bdrv_reopen_abort() when
+ * the respective bdrv_reopen_prepare() failed) */
+ if (drv->bdrv_reopen_abort) {
+ drv->bdrv_reopen_abort(reopen_state);
+ }
+ qemu_opts_del(opts);
+ qobject_unref(orig_reopen_opts);
+ g_free(discard);
+ return ret;
}
/*
--
2.17.2