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Commit cbe47ec5 authored by NeilBrown's avatar NeilBrown
Browse files

md/raid5: Protect some more code with ->device_lock. 



Other places that change or follow dev->towrite and dev->written take
the device_lock as well as the sh->lock.
So it should really be held in these places too.
Also, doing so will allow sh->lock to be discarded.

with merged fixes by: Namhyung Kim <namhyung@gmail.com>


Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Reviewed-by: default avatarNamhyung Kim <namhyung@gmail.com>
parent 83206d66

drivers/md/raid5.c

+16 −14
Original line number Diff line number Diff line
@@ -1021,10 +1021,12 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) 
			struct bio *wbi;



			spin_lock(&sh->lock);

			spin_lock_irq(&sh->raid_conf->device_lock);

			chosen = dev->towrite;

			dev->towrite = NULL;

			BUG_ON(dev->written);

			wbi = dev->written = chosen;

			spin_unlock_irq(&sh->raid_conf->device_lock);

			spin_unlock(&sh->lock);



			while (wbi && wbi->bi_sector <
@@ -2141,7 +2143,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in 
	raid5_conf_t *conf = sh->raid_conf;

	int firstwrite=0;



	pr_debug("adding bh b#%llu to stripe s#%llu\n",

	pr_debug("adding bi b#%llu to stripe s#%llu\n",

		(unsigned long long)bi->bi_sector,

		(unsigned long long)sh->sector);
@@ -2167,19 +2169,6 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in 
		bi->bi_next = *bip;

	*bip = bi;

	bi->bi_phys_segments++;

	spin_unlock_irq(&conf->device_lock);

	spin_unlock(&sh->lock);



	pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",

		(unsigned long long)bi->bi_sector,

		(unsigned long long)sh->sector, dd_idx);



	if (conf->mddev->bitmap && firstwrite) {

		bitmap_startwrite(conf->mddev->bitmap, sh->sector,

				  STRIPE_SECTORS, 0);

		sh->bm_seq = conf->seq_flush+1;

		set_bit(STRIPE_BIT_DELAY, &sh->state);

	}



	if (forwrite) {

		/* check if page is covered */
@@ -2194,6 +2183,19 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in 
		if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)

			set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);

	}

	spin_unlock_irq(&conf->device_lock);

	spin_unlock(&sh->lock);



	pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",

		(unsigned long long)(*bip)->bi_sector,

		(unsigned long long)sh->sector, dd_idx);



	if (conf->mddev->bitmap && firstwrite) {

		bitmap_startwrite(conf->mddev->bitmap, sh->sector,

				  STRIPE_SECTORS, 0);

		sh->bm_seq = conf->seq_flush+1;

		set_bit(STRIPE_BIT_DELAY, &sh->state);

	}

	return 1;



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