On Sun, Jan 26, 2014 at 08:02:42PM +0100, Max Reitz wrote:
> The fail and success paths of bdrv_file_open() may be further shortened
> by reusing code already existent in bdrv_open(). This includes
> bdrv_file_open() not taking the reference to options which allows the
> removal of QDECREF(options) in that function.
>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> ---
> block.c | 33 ++++++++++++---------------------
> 1 file changed, 12 insertions(+), 21 deletions(-)
>
> diff --git a/block.c b/block.c
> index f847c4b..b1bae23 100644
> --- a/block.c
> +++ b/block.c
> @@ -943,9 +943,7 @@ free_and_fail:
> * Opens a file using a protocol (file, host_device, nbd, ...)
> *
> * options is a QDict of options to pass to the block drivers, or NULL for an
> - * empty set of options. The reference to the QDict belongs to the block
> layer
> - * after the call (even on failure), so if the caller intends to reuse the
> - * dictionary, it needs to use QINCREF() before calling bdrv_file_open.
> + * empty set of options.
> */
> static int bdrv_file_open(BlockDriverState *bs, const char *filename,
> QDict *options, int flags, Error **errp)
> @@ -1010,8 +1008,8 @@ static int bdrv_file_open(BlockDriverState *bs, const
> char *filename,
> }
>
> if (!drv->bdrv_file_open) {
> + QINCREF(options);
> ret = bdrv_open(&bs, filename, NULL, options, flags, drv,
> &local_err);
> - options = NULL;
> } else {
> ret = bdrv_open_common(bs, NULL, options, flags, drv, &local_err);
> }
> @@ -1020,21 +1018,10 @@ static int bdrv_file_open(BlockDriverState *bs, const
> char *filename,
> goto fail;
> }
>
> - /* Check if any unknown options were used */
> - if (options && (qdict_size(options) != 0)) {
> - const QDictEntry *entry = qdict_first(options);
> - error_setg(errp, "Block protocol '%s' doesn't support the option
> '%s'",
> - drv->format_name, entry->key);
> - ret = -EINVAL;
> - goto fail;
> - }
> - QDECREF(options);
> -
> bs->growable = 1;
> return 0;
>
> fail:
> - QDECREF(options);
> return ret;
> }
>
> @@ -1238,7 +1225,6 @@ int bdrv_open(BlockDriverState **pbs, const char
> *filename,
> assert(!drv);
> ret = bdrv_file_open(bs, filename, options, flags & ~BDRV_O_PROTOCOL,
> &local_err);
> - options = NULL;
> if (ret) {
> if (bs->drv) {
> goto close_and_fail;
> @@ -1246,8 +1232,7 @@ int bdrv_open(BlockDriverState **pbs, const char
> *filename,
> goto fail;
> }
> }
> - *pbs = bs;
> - return 0;
> + goto done;
> }
>
> /* For snapshot=on, create a temporary qcow2 overlay */
> @@ -1377,12 +1362,18 @@ int bdrv_open(BlockDriverState **pbs, const char
> *filename,
> }
> }
>
> +done:
> /* Check if any unknown options were used */
> if (qdict_size(options) != 0) {
> const QDictEntry *entry = qdict_first(options);
> - error_setg(errp, "Block format '%s' used by device '%s' doesn't "
> - "support the option '%s'", drv->format_name,
> bs->device_name,
> - entry->key);
> + if (flags & BDRV_O_PROTOCOL) {
> + error_setg(errp, "Block protocol '%s' doesn't support the option
> "
> + "'%s'", drv->format_name, entry->key);
Tests 071 and 072 segfault, and gdb shows that it occurs here. More
investigation shows that entry is NULL, although qdict_size() is
returning 1.
> + } else {
> + error_setg(errp, "Block format '%s' used by device '%s' doesn't "
> + "support the option '%s'", drv->format_name,
> + bs->device_name, entry->key);
> + }
>
> ret = -EINVAL;
> goto close_and_fail;
> --
> 1.8.5.3
>
>
