Re: [PATCH 2/2] xen/grant: introduce func gnttab_unmap_refs_async_wait_completion()
From: Konrad Rzeszutek Wilk
Date: Thu Mar 26 2015 - 15:02:04 EST
On Thu, Mar 26, 2015 at 08:16:01PM +0800, Bob Liu wrote:
> There are several place using gnttab async unmap and wait for
> completion, so move the common code to a function
> gnttab_unmap_refs_async_wait_completion().
>
> Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx>
Jens, and would you be OK if this patch went through the Xen tree?
Thanks.
> ---
> drivers/block/xen-blkback/blkback.c | 31 +++----------------------------
> drivers/xen/gntdev.c | 28 +++-------------------------
> drivers/xen/grant-table.c | 29 +++++++++++++++++++++++++++++
> include/xen/grant_table.h | 1 +
> 4 files changed, 36 insertions(+), 53 deletions(-)
>
> diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
> index f59d7c3..0c8da82 100644
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
> @@ -263,17 +263,6 @@ static void put_persistent_gnt(struct xen_blkif *blkif,
> atomic_dec(&blkif->persistent_gnt_in_use);
> }
>
> -static void free_persistent_gnts_unmap_callback(int result,
> - struct gntab_unmap_queue_data *data)
> -{
> - struct completion *c = data->data;
> -
> - /* BUG_ON used to reproduce existing behaviour,
> - but is this the best way to deal with this? */
> - BUG_ON(result);
> - complete(c);
> -}
> -
> static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
> unsigned int num)
> {
> @@ -283,12 +272,7 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
> struct rb_node *n;
> int segs_to_unmap = 0;
> struct gntab_unmap_queue_data unmap_data;
> - struct completion unmap_completion;
> -
> - init_completion(&unmap_completion);
>
> - unmap_data.data = &unmap_completion;
> - unmap_data.done = &free_persistent_gnts_unmap_callback;
> unmap_data.pages = pages;
> unmap_data.unmap_ops = unmap;
> unmap_data.kunmap_ops = NULL;
> @@ -308,8 +292,7 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
> !rb_next(&persistent_gnt->node)) {
>
> unmap_data.count = segs_to_unmap;
> - gnttab_unmap_refs_async(&unmap_data);
> - wait_for_completion(&unmap_completion);
> + BUG_ON(gnttab_unmap_refs_async_wait_completion(&unmap_data));
>
> put_free_pages(blkif, pages, segs_to_unmap);
> segs_to_unmap = 0;
> @@ -330,12 +313,7 @@ void xen_blkbk_unmap_purged_grants(struct work_struct *work)
> int segs_to_unmap = 0;
> struct xen_blkif *blkif = container_of(work, typeof(*blkif), persistent_purge_work);
> struct gntab_unmap_queue_data unmap_data;
> - struct completion unmap_completion;
>
> - init_completion(&unmap_completion);
> -
> - unmap_data.data = &unmap_completion;
> - unmap_data.done = &free_persistent_gnts_unmap_callback;
> unmap_data.pages = pages;
> unmap_data.unmap_ops = unmap;
> unmap_data.kunmap_ops = NULL;
> @@ -355,9 +333,7 @@ void xen_blkbk_unmap_purged_grants(struct work_struct *work)
>
> if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
> unmap_data.count = segs_to_unmap;
> - gnttab_unmap_refs_async(&unmap_data);
> - wait_for_completion(&unmap_completion);
> -
> + BUG_ON(gnttab_unmap_refs_async_wait_completion(&unmap_data));
> put_free_pages(blkif, pages, segs_to_unmap);
> segs_to_unmap = 0;
> }
> @@ -365,8 +341,7 @@ void xen_blkbk_unmap_purged_grants(struct work_struct *work)
> }
> if (segs_to_unmap > 0) {
> unmap_data.count = segs_to_unmap;
> - gnttab_unmap_refs_async(&unmap_data);
> - wait_for_completion(&unmap_completion);
> + BUG_ON(gnttab_unmap_refs_async_wait_completion(&unmap_data));
> put_free_pages(blkif, pages, segs_to_unmap);
> }
> }
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index d5bb1a3..7a88524 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -327,30 +327,10 @@ static int map_grant_pages(struct grant_map *map)
> return err;
> }
>
> -struct unmap_grant_pages_callback_data
> -{
> - struct completion completion;
> - int result;
> -};
> -
> -static void unmap_grant_callback(int result,
> - struct gntab_unmap_queue_data *data)
> -{
> - struct unmap_grant_pages_callback_data* d = data->data;
> -
> - d->result = result;
> - complete(&d->completion);
> -}
> -
> static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
> {
> int i, err = 0;
> struct gntab_unmap_queue_data unmap_data;
> - struct unmap_grant_pages_callback_data data;
> -
> - init_completion(&data.completion);
> - unmap_data.data = &data;
> - unmap_data.done= &unmap_grant_callback;
>
> if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
> int pgno = (map->notify.addr >> PAGE_SHIFT);
> @@ -367,11 +347,9 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
> unmap_data.pages = map->pages + offset;
> unmap_data.count = pages;
>
> - gnttab_unmap_refs_async(&unmap_data);
> -
> - wait_for_completion(&data.completion);
> - if (data.result)
> - return data.result;
> + err = gnttab_unmap_refs_async_wait_completion(&unmap_data);
> + if (err)
> + return err;
>
> for (i = 0; i < pages; i++) {
> if (map->unmap_ops[offset+i].status)
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index 17972fb..1dce9bc 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -123,6 +123,12 @@ struct gnttab_ops {
> int (*query_foreign_access)(grant_ref_t ref);
> };
>
> +struct unmap_refs_async_callback_data
> +{
> + struct completion completion;
> + int result;
> +};
> +
> static struct gnttab_ops *gnttab_interface;
>
> static int grant_table_version;
> @@ -863,6 +869,29 @@ void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item)
> }
> EXPORT_SYMBOL_GPL(gnttab_unmap_refs_async);
>
> +static void unmap_refs_async_callback(int result,
> + struct gntab_unmap_queue_data *data)
> +{
> + struct unmap_refs_async_callback_data* d = data->data;
> +
> + d->result = result;
> + complete(&d->completion);
> +}
> +
> +int gnttab_unmap_refs_async_wait_completion(struct gntab_unmap_queue_data* item)
> +{
> + struct unmap_refs_async_callback_data data;
> +
> + init_completion(&data.completion);
> + item->data = &data;
> + item->done= &unmap_refs_async_callback;
> + gnttab_unmap_refs_async(item);
> + wait_for_completion(&data.completion);
> +
> + return data.result;
> +}
> +EXPORT_SYMBOL_GPL(gnttab_unmap_refs_async_wait_completion);
> +
> static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes)
> {
> int rc;
> diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
> index 143ca5f..46bad05 100644
> --- a/include/xen/grant_table.h
> +++ b/include/xen/grant_table.h
> @@ -191,6 +191,7 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
> struct gnttab_unmap_grant_ref *kunmap_ops,
> struct page **pages, unsigned int count);
> void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item);
> +int gnttab_unmap_refs_async_wait_completion(struct gntab_unmap_queue_data* item);
>
>
> /* Perform a batch of grant map/copy operations. Retry every batch slot
> --
> 1.8.3.1
>
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