Commit 2c58f06e authored by NeilBrown's avatar NeilBrown
Browse files

md/raid5: separate large if clause out of fetch_block(). 



fetch_block() has a very large and hard to read 'if' condition.

Separate it into its own function so that it can be
made more readable.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent ad3ab8b6

drivers/md/raid5.c

+15 −4
Original line number Diff line number Diff line
@@ -2895,14 +2895,14 @@ static int want_replace(struct stripe_head *sh, int disk_idx) 
 * Returns 1 when no more member devices need to be checked, otherwise returns

 * 0 to tell the loop in handle_stripe_fill to continue

 */

static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,



static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s,

			   int disk_idx, int disks)

{

	struct r5dev *dev = &sh->dev[disk_idx];

	struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],

				  &sh->dev[s->failed_num[1]] };



	/* is the data in this block needed, and can we get it? */

	if (!test_bit(R5_LOCKED, &dev->flags) &&

	    !test_bit(R5_UPTODATE, &dev->flags) &&

	    (dev->toread ||
@@ -2919,7 +2919,18 @@ static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s, 
	      && s->failed && s->to_write &&

	      (s->to_write - s->non_overwrite <

	       sh->raid_conf->raid_disks - sh->raid_conf->max_degraded) &&

	      (!test_bit(R5_Insync, &dev->flags) || test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))))) {

	      (!test_bit(R5_Insync, &dev->flags) || test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)))))

		return 1;

	return 0;

}



static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,

		       int disk_idx, int disks)

{

	struct r5dev *dev = &sh->dev[disk_idx];



	/* is the data in this block needed, and can we get it? */

	if (need_this_block(sh, s, disk_idx, disks)) {

		/* we would like to get this block, possibly by computing it,

		 * otherwise read it if the backing disk is insync

		 */