[PATCH] md: remove some old ifdefed-out code from raid5.c

There are some vestiges of old code that was used for bypassing the stripe
cache on reads in raid5.c.  This was never updated after the change from
buffer_heads to bios, but was left as a reminder.

That functionality has nowe been implemented in a completely different way, so
the old code can go.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/md/raid5.c

@@ -544,35 +544,7 @@ static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
 	}
 
 	if (uptodate) {
-#if 0
-		struct bio *bio;
-		unsigned long flags;
-		spin_lock_irqsave(&conf->device_lock, flags);
-		/* we can return a buffer if we bypassed the cache or
-		 * if the top buffer is not in highmem.  If there are
-		 * multiple buffers, leave the extra work to
-		 * handle_stripe
-		 */
-		buffer = sh->bh_read[i];
-		if (buffer &&
-		    (!PageHighMem(buffer->b_page)
-		     || buffer->b_page == bh->b_page )
-			) {
-			sh->bh_read[i] = buffer->b_reqnext;
-			buffer->b_reqnext = NULL;
-		} else
-			buffer = NULL;
-		spin_unlock_irqrestore(&conf->device_lock, flags);
-		if (sh->bh_page[i]==bh->b_page)
-			set_buffer_uptodate(bh);
-		if (buffer) {
-			if (buffer->b_page != bh->b_page)
-				memcpy(buffer->b_data, bh->b_data, bh->b_size);
-			buffer->b_end_io(buffer, 1);
-		}
-#else
 		set_bit(R5_UPTODATE, &sh->dev[i].flags);
-#endif
 		if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
 			rdev = conf->disks[i].rdev;
 			printk(KERN_INFO "raid5:%s: read error corrected (%lu sectors at %llu on %s)\n",
@@ -618,14 +590,6 @@ static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
 		}
 	}
 	rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
-#if 0
-	/* must restore b_page before unlocking buffer... */
-	if (sh->bh_page[i] != bh->b_page) {
-		bh->b_page = sh->bh_page[i];
-		bh->b_data = page_address(bh->b_page);
-		clear_buffer_uptodate(bh);
-	}
-#endif
 	clear_bit(R5_LOCKED, &sh->dev[i].flags);
 	set_bit(STRIPE_HANDLE, &sh->state);
 	release_stripe(sh);
@@ -1619,15 +1583,6 @@ static void handle_stripe5(struct stripe_head *sh)
 				} else if (test_bit(R5_Insync, &dev->flags)) {
 					set_bit(R5_LOCKED, &dev->flags);
 					set_bit(R5_Wantread, &dev->flags);
-#if 0
-					/* if I am just reading this block and we don't have
-					   a failed drive, or any pending writes then sidestep the cache */
-					if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext &&
-					    ! syncing && !failed && !to_write) {
-						sh->bh_cache[i]->b_page =  sh->bh_read[i]->b_page;
-						sh->bh_cache[i]->b_data =  sh->bh_read[i]->b_data;
-					}
-#endif
 					locked++;
 					PRINTK("Reading block %d (sync=%d)\n", 
 						i, syncing);
@@ -1645,9 +1600,6 @@ static void handle_stripe5(struct stripe_head *sh)
 			dev = &sh->dev[i];
 			if ((dev->towrite || i == sh->pd_idx) &&
 			    (!test_bit(R5_LOCKED, &dev->flags) 
-#if 0
-|| sh->bh_page[i]!=bh->b_page
-#endif
 				    ) &&
 			    !test_bit(R5_UPTODATE, &dev->flags)) {
 				if (test_bit(R5_Insync, &dev->flags)
@@ -1659,9 +1611,6 @@ static void handle_stripe5(struct stripe_head *sh)
 			/* Would I have to read this buffer for reconstruct_write */
 			if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
 			    (!test_bit(R5_LOCKED, &dev->flags) 
-#if 0
-|| sh->bh_page[i] != bh->b_page
-#endif
 				    ) &&
 			    !test_bit(R5_UPTODATE, &dev->flags)) {
 				if (test_bit(R5_Insync, &dev->flags)) rcw++;
@@ -2197,15 +2146,6 @@ static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
 				} else if (test_bit(R5_Insync, &dev->flags)) {
 					set_bit(R5_LOCKED, &dev->flags);
 					set_bit(R5_Wantread, &dev->flags);
-#if 0
-					/* if I am just reading this block and we don't have
-					   a failed drive, or any pending writes then sidestep the cache */
-					if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext &&
-					    ! syncing && !failed && !to_write) {
-						sh->bh_cache[i]->b_page =  sh->bh_read[i]->b_page;
-						sh->bh_cache[i]->b_data =  sh->bh_read[i]->b_data;
-					}
-#endif
 					locked++;
 					PRINTK("Reading block %d (sync=%d)\n",
 						i, syncing);
@@ -2224,9 +2164,6 @@ static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
 			if (!test_bit(R5_OVERWRITE, &dev->flags)
 			    && i != pd_idx && i != qd_idx
 			    && (!test_bit(R5_LOCKED, &dev->flags)
-#if 0
-				|| sh->bh_page[i] != bh->b_page
-#endif
 				    ) &&
 			    !test_bit(R5_UPTODATE, &dev->flags)) {
 				if (test_bit(R5_Insync, &dev->flags)) rcw++;