From: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, kwolf@redhat.com, mreitz@redhat.com,
stefanha@redhat.com, fam@euphon.net, jsnow@redhat.com,
armbru@redhat.com, eblake@redhat.com, den@openvz.org
Subject: Re: [PATCH v10 2/9] copy-on-read: add filter append/drop functions
Date: Mon, 5 Oct 2020 19:23:43 +0300 [thread overview]
Message-ID: <ba52d896-f876-6000-ec9c-1be98dfb6ebe@virtuozzo.com> (raw)
In-Reply-To: <777a8fc5-293b-2866-bbdf-01b181291b40@virtuozzo.com>
On 05.10.2020 16:34, Vladimir Sementsov-Ogievskiy wrote:
> 29.09.2020 15:38, Andrey Shinkevich wrote:
>> Provide API for the COR-filter insertion/removal.
>> Also, drop the filter child permissions for an inactive state when the
>> filter node is being removed.
>>
>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
>> ---
>> block/copy-on-read.c | 84
>> ++++++++++++++++++++++++++++++++++++++++++++++++++++
>> block/copy-on-read.h | 35 ++++++++++++++++++++++
>> 2 files changed, 119 insertions(+)
>> create mode 100644 block/copy-on-read.h
>>
>> diff --git a/block/copy-on-read.c b/block/copy-on-read.c
>> index cb03e0f..3c8231f 100644
>> --- a/block/copy-on-read.c
>> +++ b/block/copy-on-read.c
>> @@ -23,11 +23,21 @@
>> #include "qemu/osdep.h"
>> #include "block/block_int.h"
>> #include "qemu/module.h"
>> +#include "qapi/error.h"
>> +#include "qapi/qmp/qdict.h"
>> +#include "block/copy-on-read.h"
>> +
>> +
>> +typedef struct BDRVStateCOR {
>> + bool active;
>> +} BDRVStateCOR;
>> static int cor_open(BlockDriverState *bs, QDict *options, int flags,
>> Error **errp)
>> {
>> + BDRVStateCOR *state = bs->opaque;
>> +
>> bs->file = bdrv_open_child(NULL, options, "file", bs,
>> &child_of_bds,
>> BDRV_CHILD_FILTERED |
>> BDRV_CHILD_PRIMARY,
>> false, errp);
>> @@ -42,6 +52,13 @@ static int cor_open(BlockDriverState *bs, QDict
>> *options, int flags,
>> ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
>> bs->file->bs->supported_zero_flags);
>> + state->active = true;
>> +
>> + /*
>> + * We don't need to call bdrv_child_refresh_perms() now as the
>> permissions
>> + * will be updated later when the filter node gets its parent.
>> + */
>> +
>> return 0;
>> }
>> @@ -57,6 +74,17 @@ static void cor_child_perm(BlockDriverState *bs,
>> BdrvChild *c,
>> uint64_t perm, uint64_t shared,
>> uint64_t *nperm, uint64_t *nshared)
>> {
>> + BDRVStateCOR *s = bs->opaque;
>> +
>> + if (!s->active) {
>> + /*
>> + * While the filter is being removed
>> + */
>> + *nperm = 0;
>> + *nshared = BLK_PERM_ALL;
>> + return;
>> + }
>> +
>> *nperm = perm & PERM_PASSTHROUGH;
>> *nshared = (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED;
>> @@ -135,6 +163,7 @@ static void cor_lock_medium(BlockDriverState *bs,
>> bool locked)
>> static BlockDriver bdrv_copy_on_read = {
>> .format_name = "copy-on-read",
>> + .instance_size = sizeof(BDRVStateCOR),
>> .bdrv_open = cor_open,
>> .bdrv_child_perm = cor_child_perm,
>> @@ -159,4 +188,59 @@ static void bdrv_copy_on_read_init(void)
>> bdrv_register(&bdrv_copy_on_read);
>> }
>> +
>> +BlockDriverState *bdrv_cor_filter_append(BlockDriverState *bs,
>> + QDict *node_options,
>> + int flags, Error **errp)
>
>
> Ok, now function can add ~any filter, not only COR.. But it's a pair for
> bdrv_cor_filter_drop(), and with "active" hack we don't want make the
> functions generic I think. So it's OK for now to keep function here and
> named _cor_.
>
>> +{
>> + BlockDriverState *cor_filter_bs;
>> + Error *local_err = NULL;
>> +
>> + cor_filter_bs = bdrv_open(NULL, NULL, node_options, flags, errp);
>> + if (cor_filter_bs == NULL) {
>> + error_prepend(errp, "Could not create COR-filter node: ");
>> + return NULL;
>> + }
>
> You've dropped setting ->implicit field if filter_node_name not
> specified. Probably caller now can do it.. I don't really care about
> implicit case, so it's OK for me if it works with iotests.
Thank you for your R-B. The idea behind setting the 'implicit' member by
a caller is to prepare the code for the node replacement by a function
at the block generic layer in future. In the scope of this series, that
may be better to keep it here.
Andrey
>
> So,
>
> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>
>
next prev parent reply other threads:[~2020-10-05 16:25 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-29 12:38 [PATCH v10 0/9] Apply COR-filter to the block-stream permanently Andrey Shinkevich via
2020-09-29 12:38 ` [PATCH v10 1/9] copy-on-read: Support preadv/pwritev_part functions Andrey Shinkevich via
2020-09-29 12:38 ` [PATCH v10 2/9] copy-on-read: add filter append/drop functions Andrey Shinkevich via
2020-10-05 13:34 ` Vladimir Sementsov-Ogievskiy
2020-10-05 16:23 ` Andrey Shinkevich [this message]
2020-09-29 12:38 ` [PATCH v10 3/9] qapi: add filter-node-name to block-stream Andrey Shinkevich via
2020-09-29 12:38 ` [PATCH v10 4/9] copy-on-read: pass base node name to COR driver Andrey Shinkevich via
2020-10-05 14:50 ` Vladimir Sementsov-Ogievskiy
2020-09-29 12:38 ` [PATCH v10 5/9] copy-on-read: limit guest COR activity to base in " Andrey Shinkevich via
2020-10-05 14:58 ` Vladimir Sementsov-Ogievskiy
2020-10-05 16:45 ` Andrey Shinkevich
2020-10-05 18:18 ` Andrey Shinkevich
2020-09-29 12:38 ` [PATCH v10 6/9] copy-on-read: skip non-guest reads if no copy needed Andrey Shinkevich via
2020-10-07 10:06 ` Vladimir Sementsov-Ogievskiy
2020-10-07 19:01 ` Andrey Shinkevich
2020-10-07 19:28 ` Vladimir Sementsov-Ogievskiy
2020-10-09 12:56 ` Andrey Shinkevich
2020-09-29 12:38 ` [PATCH v10 7/9] stream: skip filters when writing backing file name to QCOW2 header Andrey Shinkevich via
2020-10-07 10:14 ` Vladimir Sementsov-Ogievskiy
2020-09-29 12:38 ` [PATCH v10 8/9] block: remove unused backing-file name parameter Andrey Shinkevich via
2020-10-07 10:21 ` Vladimir Sementsov-Ogievskiy
2020-10-07 19:32 ` Andrey Shinkevich
2020-09-29 12:38 ` [PATCH v10 9/9] block: apply COR-filter to block-stream jobs Andrey Shinkevich via
2020-10-07 17:27 ` Andrey Shinkevich
2020-10-07 17:39 ` Andrey Shinkevich
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