From: Goldwyn Rodrigues <[email protected]> Set queue flags to QUEUE_FLAG_NOWAIT to indicate REQ_NOWAIT will be handled. If any of the underlying devices do not support NOWAIT feature, we do not set the flag.
If the device is suspended, it returns -EWOULDBLOCK. Signed-off-by: Goldwyn Rodrigues <[email protected]> --- drivers/md/md.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/md/md.c b/drivers/md/md.c index 0ff1bbf6c90e..7325f8be36b4 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -237,6 +237,19 @@ EXPORT_SYMBOL_GPL(md_new_event); static LIST_HEAD(all_mddevs); static DEFINE_SPINLOCK(all_mddevs_lock); +static bool is_suspended(struct mddev *mddev, struct bio *bio) +{ + /* We can serve READ requests when device is suspended */ + if (bio_data_dir(bio) == READ) + return false; + + if (mddev->suspended) + return true; + + return (mddev->suspend_lo < bio_end_sector(bio) && + mddev->suspend_hi > bio->bi_iter.bi_sector); +} + /* * iterates through all used mddevs in the system. * We take care to grab the all_mddevs_lock whenever navigating @@ -316,6 +329,11 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio) bio_endio(bio); return BLK_QC_T_NONE; } + /* Bail out if we would have to wait for suspended device */ + if ((bio->bi_opf & REQ_NOWAIT) && is_suspended(mddev, bio)) { + bio_wouldblock_error(bio); + return BLK_QC_T_NONE; + } /* * save the sectors now since our bio can @@ -5404,6 +5422,7 @@ int md_run(struct mddev *mddev) int err; struct md_rdev *rdev; struct md_personality *pers; + bool nowait = true; if (list_empty(&mddev->disks)) /* cannot run an array with no devices.. */ @@ -5470,8 +5489,15 @@ int md_run(struct mddev *mddev) } } sysfs_notify_dirent_safe(rdev->sysfs_state); + if (!blk_queue_supports_nowait(rdev->bdev->bd_queue)) + nowait = false; } + /* Set the NOWAIT flags if all underlying devices support it */ + if (nowait) + queue_flag_set_unlocked(QUEUE_FLAG_NOWAIT, mddev->queue); + + if (mddev->bio_set == NULL) { mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); if (!mddev->bio_set) @@ -6554,6 +6580,15 @@ static int hot_add_disk(struct mddev *mddev, dev_t dev) set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags); if (!mddev->thread) md_update_sb(mddev, 1); + + /* If the new disk does not support REQ_NOWAIT, + disable on whole MD */ + if (!blk_queue_supports_nowait(rdev->bdev->bd_queue)) { + pr_info("%s: Disabling nowait because %s does not support nowait\n", + mdname(mddev), bdevname(rdev->bdev,b)); + queue_flag_clear_unlocked(QUEUE_FLAG_NOWAIT, mddev->queue); + } + /* * Kick recovery, maybe this spare has to be added to the * array immediately. -- 2.14.2
