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: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index f2f2ab3..9985138 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1021,10 +1021,12 @@
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 @@
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 @@
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 @@
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;
overlap: