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authorNeilBrown <neilb@suse.de>2012-07-31 11:08:14 +0400
committerJens Axboe <axboe@kernel.dk>2012-07-31 11:08:14 +0400
commit9cbb17508808f8a6bdd83354b61e126ac4fa6fed (patch)
treebc797d1b5cd829751a333115e6e6d52799fb6df2 /drivers/md
parent0021b7bc045e4b0b85d8c53614342aaf84ca96a5 (diff)
downloadlinux-9cbb17508808f8a6bdd83354b61e126ac4fa6fed.tar.xz
blk: centralize non-request unplug handling.
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@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/md.c56
-rw-r--r--drivers/md/md.h8
2 files changed, 12 insertions, 52 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 34381172a947..b493fa417387 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 91786c46b85c..8f998e08fb87 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 */