Both md and umem has similar code for getting notified on an
blk_finish_plug event.
Centralize this code in block/ and allow each driver to
provide its distinctive difference.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
block/blk-core.c | 25 +++++++++++++++++++++
drivers/block/umem.c | 35 +++++-------------------------
drivers/md/md.c | 56 ++++--------------------------------------------
drivers/md/md.h | 8 ++++++-
include/linux/blkdev.h | 8 +++++--
5 files changed, 49 insertions(+), 83 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 93eb3e4..7296d3d 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2914,6 +2914,31 @@ static void flush_plug_callbacks(struct blk_plug *plug)
}
}
+struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data,
+ int size)
+{
+ struct blk_plug *plug = current->plug;
+ struct blk_plug_cb *cb;
+
+ if (!plug)
+ return NULL;
+
+ list_for_each_entry(cb, &plug->cb_list, list)
+ if (cb->callback == unplug && cb->data == data)
+ return cb;
+
+ /* Not currently on the callback list */
+ BUG_ON(size < sizeof(*cb));
+ cb = kzalloc(size, GFP_ATOMIC);
+ if (cb) {
+ cb->data = data;
+ cb->callback = unplug;
+ list_add(&cb->list, &plug->cb_list);
+ }
+ return cb;
+}
+EXPORT_SYMBOL(blk_check_plugged);
+
void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
{
struct request_queue *q;
diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 9a72277..6ef3489 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -513,42 +513,19 @@ static void process_page(unsigned long data)
}
}
-struct mm_plug_cb {
- struct blk_plug_cb cb;
- struct cardinfo *card;
-};
-
static void mm_unplug(struct blk_plug_cb *cb)
{
- struct mm_plug_cb *mmcb = container_of(cb, struct mm_plug_cb, cb);
+ struct cardinfo *card = cb->data;
- spin_lock_irq(&mmcb->card->lock);
- activate(mmcb->card);
- spin_unlock_irq(&mmcb->card->lock);
- kfree(mmcb);
+ spin_lock_irq(&card->lock);
+ activate(card);
+ spin_unlock_irq(&card->lock);
+ kfree(cb);
}
static int mm_check_plugged(struct cardinfo *card)
{
- struct blk_plug *plug = current->plug;
- struct mm_plug_cb *mmcb;
-
- if (!plug)
- return 0;
-
- list_for_each_entry(mmcb, &plug->cb_list, cb.list) {
- if (mmcb->cb.callback == mm_unplug && mmcb->card == card)
- return 1;
- }
- /* Not currently on the callback list */
- mmcb = kmalloc(sizeof(*mmcb), GFP_ATOMIC);
- if (!mmcb)
- return 0;
-
- mmcb->card = card;
- mmcb->cb.callback = mm_unplug;
- list_add(&mmcb->cb.list, &plug->cb_list);
- return 1;
+ return !!blk_check_plugged(mm_unplug, card, sizeof(struct blk_plug_cb));
}
static void mm_make_request(struct request_queue *q, struct bio *bio)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3438117..b493fa4 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -498,59 +498,13 @@ void md_flush_request(struct mddev *mddev, struct bio *bio)
}
EXPORT_SYMBOL(md_flush_request);
-/* Support for plugging.
- * This mirrors the plugging support in request_queue, but does not
- * require having a whole queue or request structures.
- * We allocate an md_plug_cb for each md device and each thread it gets
- * plugged on. This links tot the private plug_handle structure in the
- * personality data where we keep a count of the number of outstanding
- * plugs so other code can see if a plug is active.
- */
-struct md_plug_cb {
- struct blk_plug_cb cb;
- struct mddev *mddev;
-};
-
-static void plugger_unplug(struct blk_plug_cb *cb)
+void md_unplug(struct blk_plug_cb *cb)
{
- struct md_plug_cb *mdcb = container_of(cb, struct md_plug_cb, cb);
- md_wakeup_thread(mdcb->mddev->thread);
- kfree(mdcb);
-}
-
-/* Check that an unplug wakeup will come shortly.
- * If not, wakeup the md thread immediately
- */
-int mddev_check_plugged(struct mddev *mddev)
-{
- struct blk_plug *plug = current->plug;
- struct md_plug_cb *mdcb;
-
- if (!plug)
- return 0;
-
- list_for_each_entry(mdcb, &plug->cb_list, cb.list) {
- if (mdcb->cb.callback == plugger_unplug &&
- mdcb->mddev == mddev) {
- /* Already on the list, move to top */
- if (mdcb != list_first_entry(&plug->cb_list,
- struct md_plug_cb,
- cb.list))
- list_move(&mdcb->cb.list, &plug->cb_list);
- return 1;
- }
- }
- /* Not currently on the callback list */
- mdcb = kmalloc(sizeof(*mdcb), GFP_ATOMIC);
- if (!mdcb)
- return 0;
-
- mdcb->mddev = mddev;
- mdcb->cb.callback = plugger_unplug;
- list_add(&mdcb->cb.list, &plug->cb_list);
- return 1;
+ struct mddev *mddev = cb->data;
+ md_wakeup_thread(mddev->thread);
+ kfree(cb);
}
-EXPORT_SYMBOL_GPL(mddev_check_plugged);
+EXPORT_SYMBOL(md_unplug);
static inline struct mddev *mddev_get(struct mddev *mddev)
{
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 91786c4..8f998e0 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -627,6 +627,12 @@ extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
struct mddev *mddev);
extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
struct mddev *mddev);
-extern int mddev_check_plugged(struct mddev *mddev);
extern void md_trim_bio(struct bio *bio, int offset, int size);
+
+extern void md_unplug(struct blk_plug_cb *cb);
+static inline int mddev_check_plugged(struct mddev *mddev)
+{
+ return !!blk_check_plugged(md_unplug, mddev,
+ sizeof(struct blk_plug_cb));
+}
#endif /* _MD_MD_H */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 07954b0..68ba19d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -911,11 +911,15 @@ struct blk_plug {
};
#define BLK_MAX_REQUEST_COUNT 16
+struct blk_plug_cb;
+typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *);
struct blk_plug_cb {
struct list_head list;
- void (*callback)(struct blk_plug_cb *);
+ blk_plug_cb_fn callback;
+ void *data;
};
-
+extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
+ void *data, int size);
extern void blk_start_plug(struct blk_plug *);
extern void blk_finish_plug(struct blk_plug *);
extern void blk_flush_plug_list(struct blk_plug *, bool);
--
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