From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shaohua Li Subject: [patch 07/10 v3] md: personality can provide unplug private data Date: Mon, 25 Jun 2012 15:24:54 +0800 Message-ID: <20120625072653.743080746@kernel.org> References: <20120625072447.268095276@kernel.org> Return-path: Content-Disposition: inline; filename=md-plug-add-callback.patch Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org Cc: neilb@suse.de, axboe@kernel.dk, dan.j.williams@intel.com, shli@fusionio.com List-Id: linux-raid.ids Allow personality providing unplug private data. Next patch will use it. Signed-off-by: Shaohua Li --- drivers/md/md.c | 31 +++++++++++++------------------ drivers/md/md.h | 20 +++++++++++++++++++- drivers/md/raid1.c | 2 +- drivers/md/raid10.c | 2 +- drivers/md/raid5.c | 2 +- 5 files changed, 35 insertions(+), 22 deletions(-) Index: linux/drivers/md/md.c =================================================================== --- linux.orig/drivers/md/md.c 2012-06-25 14:36:13.668642048 +0800 +++ linux/drivers/md/md.c 2012-06-25 14:38:33.106889041 +0800 @@ -498,22 +498,13 @@ void md_flush_request(struct mddev *mdde } 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) { struct md_plug_cb *mdcb = container_of(cb, struct md_plug_cb, cb); + + if (mdcb->unplug) + mdcb->unplug(mdcb); if (atomic_dec_and_test(&mdcb->mddev->plug_cnt)) md_wakeup_thread(mdcb->mddev->thread); kfree(mdcb); @@ -522,13 +513,14 @@ static void plugger_unplug(struct blk_pl /* Check that an unplug wakeup will come shortly. * If not, wakeup the md thread immediately */ -int mddev_check_plugged(struct mddev *mddev) +struct md_plug_cb *mddev_check_plugged(struct mddev *mddev, + md_unplug_func_t unplug, size_t size) { struct blk_plug *plug = current->plug; struct md_plug_cb *mdcb; if (!plug) - return 0; + return NULL; list_for_each_entry(mdcb, &plug->cb_list, cb.list) { if (mdcb->cb.callback == plugger_unplug && @@ -538,19 +530,22 @@ int mddev_check_plugged(struct mddev *md struct md_plug_cb, cb.list)) list_move(&mdcb->cb.list, &plug->cb_list); - return 1; + return mdcb; } } /* Not currently on the callback list */ - mdcb = kmalloc(sizeof(*mdcb), GFP_ATOMIC); + mdcb = kmalloc(sizeof(*mdcb) + size, GFP_ATOMIC); if (!mdcb) - return 0; + return NULL; mdcb->mddev = mddev; mdcb->cb.callback = plugger_unplug; atomic_inc(&mddev->plug_cnt); list_add(&mdcb->cb.list, &plug->cb_list); - return 1; + mdcb->unplug = unplug; + if (size) + memset((void *)(mdcb + 1), 0, size); + return mdcb; } EXPORT_SYMBOL_GPL(mddev_check_plugged); Index: linux/drivers/md/md.h =================================================================== --- linux.orig/drivers/md/md.h 2012-06-25 14:36:13.676641948 +0800 +++ linux/drivers/md/md.h 2012-06-25 14:38:33.106889041 +0800 @@ -630,6 +630,24 @@ extern struct bio *bio_clone_mddev(struc 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); + +/* 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; +typedef void (*md_unplug_func_t)(struct md_plug_cb *mdcb); +struct md_plug_cb { + struct blk_plug_cb cb; + struct mddev *mddev; + md_unplug_func_t unplug; +}; + +extern struct md_plug_cb *mddev_check_plugged(struct mddev *mddev, + md_unplug_func_t unplug, size_t size); extern void md_trim_bio(struct bio *bio, int offset, int size); #endif /* _MD_MD_H */ Index: linux/drivers/md/raid1.c =================================================================== --- linux.orig/drivers/md/raid1.c 2012-06-25 14:36:13.696641695 +0800 +++ linux/drivers/md/raid1.c 2012-06-25 14:38:33.110889008 +0800 @@ -1034,7 +1034,7 @@ read_again: * the bad blocks. Each set of writes gets it's own r1bio * with a set of bios attached. */ - plugged = mddev_check_plugged(mddev); + plugged = !!mddev_check_plugged(mddev, NULL, 0); disks = conf->raid_disks * 2; retry_write: Index: linux/drivers/md/raid10.c =================================================================== --- linux.orig/drivers/md/raid10.c 2012-06-25 14:36:13.684641847 +0800 +++ linux/drivers/md/raid10.c 2012-06-25 14:38:33.110889008 +0800 @@ -1239,7 +1239,7 @@ read_again: * of r10_bios is recored in bio->bi_phys_segments just as with * the read case. */ - plugged = mddev_check_plugged(mddev); + plugged = !!mddev_check_plugged(mddev, NULL, 0); r10_bio->read_slot = -1; /* make sure repl_bio gets freed */ raid10_find_phys(conf, r10_bio); Index: linux/drivers/md/raid5.c =================================================================== --- linux.orig/drivers/md/raid5.c 2012-06-25 14:38:13.899130571 +0800 +++ linux/drivers/md/raid5.c 2012-06-25 14:38:33.110889008 +0800 @@ -4012,7 +4012,7 @@ static void make_request(struct mddev *m bi->bi_next = NULL; bi->bi_phys_segments = 1; /* over-loaded to count active stripes */ - plugged = mddev_check_plugged(mddev); + plugged = !!mddev_check_plugged(mddev, NULL, 0); for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { DEFINE_WAIT(w); int previous;