The Wednesday 10 Sep 2014 à 10:13:33 (+0200), Markus Armbruster wrote :
> Make the BlockBackend own the DriveInfo. Change blockdev_init() to
> return the BlockBackend instead of the DriveInfo.
>
> Signed-off-by: Markus Armbruster <arm...@redhat.com>
> ---
> block/block-backend.c | 38 +++++++++++++++++++++++
> blockdev.c | 79
> +++++++++++++++++++++--------------------------
> include/sysemu/blockdev.h | 4 +++
> 3 files changed, 78 insertions(+), 43 deletions(-)
>
> diff --git a/block/block-backend.c b/block/block-backend.c
> index deccb54..2a22660 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -12,14 +12,18 @@
>
> #include "sysemu/block-backend.h"
> #include "block/block_int.h"
> +#include "sysemu/blockdev.h"
>
> struct BlockBackend {
> char *name;
> int refcnt;
> BlockDriverState *bs;
> + DriveInfo *legacy_dinfo;
> QTAILQ_ENTRY(BlockBackend) link; /* for blk_backends */
> };
>
> +static void drive_info_del(DriveInfo *dinfo);
Is there any technical reason not to just put the
drive_info_del above the blk_delete function ?
I don't see any possible circular references between the two.
Some people like Eric frown upon static function prototypes
in final code that's why I am asking.
> +
> static QTAILQ_HEAD(, BlockBackend) blk_backends =
> QTAILQ_HEAD_INITIALIZER(blk_backends);
>
> @@ -87,6 +91,7 @@ static void blk_delete(BlockBackend *blk)
> blk_detach_bs(blk);
> QTAILQ_REMOVE(&blk_backends, blk, link);
> g_free(blk->name);
> + drive_info_del(blk->legacy_dinfo);
> g_free(blk);
> }
>
> @@ -119,6 +124,16 @@ void blk_unref(BlockBackend *blk)
> }
> }
>
> +static void drive_info_del(DriveInfo *dinfo)
> +{
> + if (dinfo) {
> + qemu_opts_del(dinfo->opts);
> + g_free(dinfo->id);
> + g_free(dinfo->serial);
> + g_free(dinfo);
> + }
> +}
> +
> const char *blk_name(BlockBackend *blk)
> {
> return blk->name;
> @@ -187,3 +202,26 @@ BlockDriverState *blk_detach_bs(BlockBackend *blk)
> }
> return bs;
> }
> +
> +DriveInfo *blk_legacy_dinfo(BlockBackend *blk)
> +{
> + return blk->legacy_dinfo;
> +}
> +
> +DriveInfo *blk_set_legacy_dinfo(BlockBackend *blk, DriveInfo *dinfo)
> +{
> + assert(!blk->legacy_dinfo);
> + return blk->legacy_dinfo = dinfo;
> +}
> +
> +BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo)
> +{
> + BlockBackend *blk;
> +
> + QTAILQ_FOREACH(blk, &blk_backends, link) {
> + if (blk->legacy_dinfo == dinfo) {
> + return blk;
> + }
> + }
> + assert(0);
> +}
> diff --git a/blockdev.c b/blockdev.c
> index 0a0b95e..73e2da9 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -47,8 +47,6 @@
> #include "trace.h"
> #include "sysemu/arch_init.h"
>
> -static QTAILQ_HEAD(drivelist, DriveInfo) drives =
> QTAILQ_HEAD_INITIALIZER(drives);
> -
> static const char *const if_name[IF_COUNT] = {
> [IF_NONE] = "none",
> [IF_IDE] = "ide",
> @@ -89,7 +87,8 @@ static const int if_max_devs[IF_COUNT] = {
> */
> void blockdev_mark_auto_del(BlockDriverState *bs)
> {
> - DriveInfo *dinfo = drive_get_by_blockdev(bs);
> + BlockBackend *blk = bs->blk;
> + DriveInfo *dinfo = blk_legacy_dinfo(blk);
>
> if (dinfo && !dinfo->enable_auto_del) {
> return;
> @@ -105,7 +104,8 @@ void blockdev_mark_auto_del(BlockDriverState *bs)
>
> void blockdev_auto_del(BlockDriverState *bs)
> {
> - DriveInfo *dinfo = drive_get_by_blockdev(bs);
> + BlockBackend *blk = bs->blk;
> + DriveInfo *dinfo = blk_legacy_dinfo(blk);
>
> if (dinfo && dinfo->auto_del) {
> drive_del(dinfo);
> @@ -153,15 +153,15 @@ QemuOpts *drive_add(BlockInterfaceType type, int index,
> const char *file,
>
> DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
> {
> + BlockBackend *blk;
> DriveInfo *dinfo;
>
> - /* seek interface, bus and unit */
> -
> - QTAILQ_FOREACH(dinfo, &drives, next) {
> - if (dinfo->type == type &&
> - dinfo->bus == bus &&
> - dinfo->unit == unit)
> + for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
Here I understand why you didn't made blk_next pure round robin circling in a
loop.
Maybe the comments of the blk_next function should say it's just an iterator.
> + dinfo = blk_legacy_dinfo(blk);
> + if (dinfo && dinfo->type == type
> + && dinfo->bus == bus && dinfo->unit == unit) {
> return dinfo;
> + }
> }
>
> return NULL;
> @@ -177,13 +177,15 @@ DriveInfo *drive_get_by_index(BlockInterfaceType type,
> int index)
> int drive_get_max_bus(BlockInterfaceType type)
> {
> int max_bus;
> + BlockBackend *blk;
> DriveInfo *dinfo;
>
> max_bus = -1;
> - QTAILQ_FOREACH(dinfo, &drives, next) {
> - if(dinfo->type == type &&
> - dinfo->bus > max_bus)
> + for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
> + dinfo = blk_legacy_dinfo(blk);
> + if (dinfo && dinfo->type == type && dinfo->bus > max_bus) {
> max_bus = dinfo->bus;
> + }
> }
> return max_bus;
> }
> @@ -200,11 +202,11 @@ DriveInfo *drive_get_next(BlockInterfaceType type)
>
> DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
> {
> - DriveInfo *dinfo;
> + BlockBackend *blk;
>
> - QTAILQ_FOREACH(dinfo, &drives, next) {
> - if (dinfo->bdrv == bs) {
> - return dinfo;
> + for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
> + if (blk_bs(blk) == bs) {
> + return blk_legacy_dinfo(blk);
> }
> }
> return NULL;
> @@ -217,16 +219,10 @@ static void bdrv_format_print(void *opaque, const char
> *name)
>
> void drive_del(DriveInfo *dinfo)
> {
> - if (dinfo->opts) {
> - qemu_opts_del(dinfo->opts);
> - }
> + BlockBackend *blk = dinfo->bdrv->blk;
>
> bdrv_unref(dinfo->bdrv);
> - blk_unref(blk_by_name(dinfo->id));
> - g_free(dinfo->id);
> - QTAILQ_REMOVE(&drives, dinfo, next);
> - g_free(dinfo->serial);
> - g_free(dinfo);
> + blk_unref(blk);
> }
>
> typedef struct {
> @@ -296,8 +292,8 @@ static bool check_throttle_config(ThrottleConfig *cfg,
> Error **errp)
> typedef enum { MEDIA_DISK, MEDIA_CDROM } DriveMediaType;
>
> /* Takes the ownership of bs_opts */
> -static DriveInfo *blockdev_init(const char *file, QDict *bs_opts,
> - Error **errp)
> +static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
> + Error **errp)
> {
> const char *buf;
> int ro = 0;
> @@ -480,7 +476,7 @@ static DriveInfo *blockdev_init(const char *file, QDict
> *bs_opts,
> dinfo = g_malloc0(sizeof(*dinfo));
> dinfo->id = g_strdup(qemu_opts_id(opts));
> dinfo->bdrv = bs;
> - QTAILQ_INSERT_TAIL(&drives, dinfo, next);
> + blk_set_legacy_dinfo(blk, dinfo);
>
> if (!file || !*file) {
> if (has_driver_specific_opts) {
> @@ -488,7 +484,7 @@ static DriveInfo *blockdev_init(const char *file, QDict
> *bs_opts,
> } else {
> QDECREF(bs_opts);
> qemu_opts_del(opts);
> - return dinfo;
> + return blk;
Here you fix the leak I found on a previous patch.
> }
> }
> if (snapshot) {
> @@ -525,13 +521,10 @@ static DriveInfo *blockdev_init(const char *file, QDict
> *bs_opts,
> QDECREF(bs_opts);
> qemu_opts_del(opts);
>
> - return dinfo;
> + return blk;
>
> err:
> bdrv_unref(dinfo->bdrv);
> - QTAILQ_REMOVE(&drives, dinfo, next);
> - g_free(dinfo->id);
> - g_free(dinfo);
> blk_unref(blk);
> early_err:
> qemu_opts_del(opts);
> @@ -635,6 +628,7 @@ QemuOptsList qemu_legacy_drive_opts = {
> DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType
> block_default_type)
> {
> const char *value;
> + BlockBackend *blk;
> DriveInfo *dinfo = NULL;
> QDict *bs_opts;
> QemuOpts *legacy_opts;
> @@ -917,19 +911,17 @@ DriveInfo *drive_new(QemuOpts *all_opts,
> BlockInterfaceType block_default_type)
> }
>
> /* Actual block device init: Functionality shared with blockdev-add */
> - dinfo = blockdev_init(filename, bs_opts, &local_err);
> + blk = blockdev_init(filename, bs_opts, &local_err);
> bs_opts = NULL;
> - if (dinfo == NULL) {
> - if (local_err) {
> - error_report("%s", error_get_pretty(local_err));
> - error_free(local_err);
> - }
> + if (!blk) {
Just down the code an existing test does if (local_err) { after
blk = blockdev_init(NULL, qdict, &local_err);.
Is the prefered convention checking blk or local_err ?
> + error_report("%s", error_get_pretty(local_err));
> goto fail;
> } else {
> assert(!local_err);
> }
>
> /* Set legacy DriveInfo fields */
> + dinfo = blk_legacy_dinfo(blk);
> dinfo->enable_auto_del = true;
> dinfo->opts = all_opts;
>
> @@ -2478,7 +2470,7 @@ void qmp_change_backing_file(const char *device,
> void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
> {
> QmpOutputVisitor *ov = qmp_output_visitor_new();
> - DriveInfo *dinfo;
> + BlockBackend *blk;
> QObject *obj;
> QDict *qdict;
> Error *local_err = NULL;
> @@ -2516,14 +2508,15 @@ void qmp_blockdev_add(BlockdevOptions *options, Error
> **errp)
>
> qdict_flatten(qdict);
>
> - dinfo = blockdev_init(NULL, qdict, &local_err);
> + blk = blockdev_init(NULL, qdict, &local_err);
> if (local_err) {
> error_propagate(errp, local_err);
> goto fail;
> }
>
> - if (bdrv_key_required(dinfo->bdrv)) {
> - drive_del(dinfo);
> + if (bdrv_key_required(blk_bs(blk))) {
> + bdrv_unref(blk_bs(blk));
> + blk_unref(blk);
> error_setg(errp, "blockdev-add doesn't support encrypted devices");
> goto fail;
> }
> diff --git a/include/sysemu/blockdev.h b/include/sysemu/blockdev.h
> index 23a5d10..2ed297b 100644
> --- a/include/sysemu/blockdev.h
> +++ b/include/sysemu/blockdev.h
> @@ -45,6 +45,10 @@ struct DriveInfo {
> QTAILQ_ENTRY(DriveInfo) next;
> };
>
> +DriveInfo *blk_legacy_dinfo(BlockBackend *blk);
> +DriveInfo *blk_set_legacy_dinfo(BlockBackend *blk, DriveInfo *dinfo);
> +BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo);
> +
> DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit);
> DriveInfo *drive_get_by_index(BlockInterfaceType type, int index);
> int drive_get_max_bus(BlockInterfaceType type);
> --
> 1.9.3
>
