diff options
Diffstat (limited to 'drivers/md/md.c')
| -rw-r--r-- | drivers/md/md.c | 87 |
1 files changed, 46 insertions, 41 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index b12b3776c0c0..6e853c61d87e 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -447,48 +447,59 @@ EXPORT_SYMBOL(md_flush_request); /* Support for plugging. * This mirrors the plugging support in request_queue, but does not - * require having a whole queue + * 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. */ -static void plugger_work(struct work_struct *work) -{ - struct plug_handle *plug = - container_of(work, struct plug_handle, unplug_work); - plug->unplug_fn(plug); -} -static void plugger_timeout(unsigned long data) -{ - struct plug_handle *plug = (void *)data; - kblockd_schedule_work(NULL, &plug->unplug_work); -} -void plugger_init(struct plug_handle *plug, - void (*unplug_fn)(struct plug_handle *)) -{ - plug->unplug_flag = 0; - plug->unplug_fn = unplug_fn; - init_timer(&plug->unplug_timer); - plug->unplug_timer.function = plugger_timeout; - plug->unplug_timer.data = (unsigned long)plug; - INIT_WORK(&plug->unplug_work, plugger_work); -} -EXPORT_SYMBOL_GPL(plugger_init); +struct md_plug_cb { + struct blk_plug_cb cb; + mddev_t *mddev; +}; -void plugger_set_plug(struct plug_handle *plug) +static void plugger_unplug(struct blk_plug_cb *cb) { - if (!test_and_set_bit(PLUGGED_FLAG, &plug->unplug_flag)) - mod_timer(&plug->unplug_timer, jiffies + msecs_to_jiffies(3)+1); + struct md_plug_cb *mdcb = container_of(cb, struct md_plug_cb, cb); + if (atomic_dec_and_test(&mdcb->mddev->plug_cnt)) + md_wakeup_thread(mdcb->mddev->thread); + kfree(mdcb); } -EXPORT_SYMBOL_GPL(plugger_set_plug); -int plugger_remove_plug(struct plug_handle *plug) +/* Check that an unplug wakeup will come shortly. + * If not, wakeup the md thread immediately + */ +int mddev_check_plugged(mddev_t *mddev) { - if (test_and_clear_bit(PLUGGED_FLAG, &plug->unplug_flag)) { - del_timer(&plug->unplug_timer); - return 1; - } else + 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; -} -EXPORT_SYMBOL_GPL(plugger_remove_plug); + mdcb->mddev = mddev; + mdcb->cb.callback = plugger_unplug; + atomic_inc(&mddev->plug_cnt); + list_add(&mdcb->cb.list, &plug->cb_list); + return 1; +} +EXPORT_SYMBOL_GPL(mddev_check_plugged); static inline mddev_t *mddev_get(mddev_t *mddev) { @@ -538,6 +549,7 @@ void mddev_init(mddev_t *mddev) atomic_set(&mddev->active, 1); atomic_set(&mddev->openers, 0); atomic_set(&mddev->active_io, 0); + atomic_set(&mddev->plug_cnt, 0); spin_lock_init(&mddev->write_lock); atomic_set(&mddev->flush_pending, 0); init_waitqueue_head(&mddev->sb_wait); @@ -4723,7 +4735,6 @@ static void md_clean(mddev_t *mddev) mddev->bitmap_info.chunksize = 0; mddev->bitmap_info.daemon_sleep = 0; mddev->bitmap_info.max_write_behind = 0; - mddev->plug = NULL; } static void __md_stop_writes(mddev_t *mddev) @@ -6688,12 +6699,6 @@ int md_allow_write(mddev_t *mddev) } EXPORT_SYMBOL_GPL(md_allow_write); -void md_unplug(mddev_t *mddev) -{ - if (mddev->plug) - mddev->plug->unplug_fn(mddev->plug); -} - #define SYNC_MARKS 10 #define SYNC_MARK_STEP (3*HZ) void md_do_sync(mddev_t *mddev) |