Remove nr_sectors from bio_end_io end I/O callback. It was a relic

from when completion was potentially called more than once to indicate
partial end I/O. These days bio->bi_end_io is _only_ called when I/O
has completed on the entire bio.

drivers/block/ll_rw_blk.c

@@ -1227,7 +1227,7 @@ static int __make_request(request_queue_t *q, struct bio *bio)
 	return 0;
 
 end_io:
-	bio->bi_end_io(bio, nr_sectors);
+	bio->bi_end_io(bio);
 	return 0;
 }
 
@@ -1329,7 +1329,7 @@ void generic_make_request(struct bio *bio)
 			       "generic_make_request: Trying to access nonexistent block-device %s (%Lu)\n",
 			       kdevname(bio->bi_dev), (long long) bio->bi_sector);
 end_io:
-			bio->bi_end_io(bio, nr_sectors);
+			bio->bi_end_io(bio);
 			break;
 		}
 
@@ -1350,15 +1350,12 @@ void generic_make_request(struct bio *bio)
 /*
  * our default bio end_io callback handler for a buffer_head mapping.
  */
-static int end_bio_bh_io_sync(struct bio *bio, int nr_sectors)
+static void end_bio_bh_io_sync(struct bio *bio)
 {
 	struct buffer_head *bh = bio->bi_private;
 
-	BIO_BUG_ON(nr_sectors != (bh->b_size >> 9));
-
 	bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags));
 	bio_put(bio);
-	return 0;
 }
 
 /**
@@ -1641,8 +1638,7 @@ int end_that_request_first(struct request *req, int uptodate, int nr_sectors)
 		if (!bio->bi_size) {
 			req->bio = bio->bi_next;
 
-			if (unlikely(bio_endio(bio, uptodate, total_nsect)))
-				BUG();
+			bio_endio(bio, uptodate);
 
 			total_nsect = 0;
 		}

drivers/md/raid1.c

@@ -225,14 +225,12 @@ static void reschedule_retry(r1bio_t *r1_bio)
  * operation and are ready to return a success/failure code to the buffer
  * cache layer.
  */
-static int raid_end_bio_io(r1bio_t *r1_bio, int uptodate, int nr_sectors)
+static void raid_end_bio_io(r1bio_t *r1_bio, int uptodate)
 {
 	struct bio *bio = r1_bio->master_bio;
 
-	bio_endio(bio, uptodate, nr_sectors);
+	bio_endio(bio, uptodate);
 	free_r1bio(r1_bio);
-
-	return 0;
 }
 
 /*
@@ -247,7 +245,7 @@ static void inline update_head_pos(int disk, r1bio_t *r1_bio)
 	atomic_dec(&conf->mirrors[disk].nr_pending);
 }
 
-static int end_request(struct bio *bio, int nr_sectors)
+static void end_request(struct bio *bio)
 {
 	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 	r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
@@ -278,8 +276,8 @@ static int end_request(struct bio *bio, int nr_sectors)
 		 * we have only one bio on the read side
 		 */
 		if (uptodate) {
-			raid_end_bio_io(r1_bio, uptodate, nr_sectors);
-			return 0;
+			raid_end_bio_io(r1_bio, uptodate);
+			return;
 		}
 		/*
 		 * oops, read error:
@@ -287,7 +285,7 @@ static int end_request(struct bio *bio, int nr_sectors)
 		printk(KERN_ERR "raid1: %s: rescheduling sector %lu\n",
 			partition_name(bio->bi_dev), r1_bio->sector);
 		reschedule_retry(r1_bio);
-		return 0;
+		return;
 	}
 
 	if (r1_bio->read_bio)
@@ -307,8 +305,7 @@ static int end_request(struct bio *bio, int nr_sectors)
 	 * already.
 	 */
 	if (atomic_dec_and_test(&r1_bio->remaining))
-		raid_end_bio_io(r1_bio, uptodate, nr_sectors);
-	return 0;
+		raid_end_bio_io(r1_bio, uptodate);
 }
 
 /*
@@ -518,7 +515,7 @@ static int make_request(mddev_t *mddev, int rw, struct bio * bio)
 		 * If all mirrors are non-operational
 		 * then return an IO error:
 		 */
-		raid_end_bio_io(r1_bio, 0, 0);
+		raid_end_bio_io(r1_bio, 0);
 		return 0;
 	}
 	atomic_set(&r1_bio->remaining, sum_bios);
@@ -930,7 +927,7 @@ static int diskop(mddev_t *mddev, mdp_disk_t **d, int state)
 #define REDIRECT_SECTOR KERN_ERR \
 "raid1: %s: redirecting sector %lu to another mirror\n"
 
-static int end_sync_read(struct bio *bio, int nr_sectors)
+static void end_sync_read(struct bio *bio)
 {
 	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 	r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
@@ -948,11 +945,9 @@ static int end_sync_read(struct bio *bio, int nr_sectors)
 	else
 		set_bit(R1BIO_Uptodate, &r1_bio->state);
 	reschedule_retry(r1_bio);
-
-	return 0;
 }
 
-static int end_sync_write(struct bio *bio, int nr_sectors)
+static void end_sync_write(struct bio *bio)
 {
 	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 	r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
@@ -974,7 +969,6 @@ static int end_sync_write(struct bio *bio, int nr_sectors)
 		resume_device(conf);
 		put_buf(r1_bio);
 	}
-	return 0;
 }
 
 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
@@ -1100,7 +1094,7 @@ static void raid1d(void *data)
 			map(mddev, &bio->bi_dev);
 			if (kdev_same(bio->bi_dev, dev)) {
 				printk(IO_ERROR, partition_name(bio->bi_dev), r1_bio->sector);
-				raid_end_bio_io(r1_bio, 0, 0);
+				raid_end_bio_io(r1_bio, 0);
 				break;
 			}
 			printk(REDIRECT_SECTOR,

fs/bio.c

@@ -316,13 +316,12 @@ struct bio *bio_copy(struct bio *bio, int gfp_mask, int copy)
 	return NULL;
 }
 
-static int bio_end_io_kio(struct bio *bio, int nr_sectors)
+static void bio_end_io_kio(struct bio *bio)
 {
 	struct kiobuf *kio = (struct kiobuf *) bio->bi_private;
 
 	end_kio_request(kio, test_bit(BIO_UPTODATE, &bio->bi_flags));
 	bio_put(bio);
-	return 0;
 }
 
 /**
@@ -441,7 +440,7 @@ void ll_rw_kio(int rw, struct kiobuf *kio, kdev_t dev, sector_t sector)
 	end_kio_request(kio, !err);
 }
 
-int bio_endio(struct bio *bio, int uptodate, int nr_sectors)
+void bio_endio(struct bio *bio, int uptodate)
 {
 	if (uptodate)
 		set_bit(BIO_UPTODATE, &bio->bi_flags);
@@ -449,9 +448,7 @@ int bio_endio(struct bio *bio, int uptodate, int nr_sectors)
 		clear_bit(BIO_UPTODATE, &bio->bi_flags);
 
 	if (bio->bi_end_io)
-		return bio->bi_end_io(bio, nr_sectors);
-
-	return 0;
+		bio->bi_end_io(bio);
 }
 
 static void __init biovec_init_pool(void)

include/linux/bio.h

@@ -50,7 +50,7 @@ struct bio_vec {
  * weee, c forward decl...
  */
 struct bio;
-typedef int (bio_end_io_t) (struct bio *, int);
+typedef void (bio_end_io_t) (struct bio *);
 typedef void (bio_destructor_t) (struct bio *);
 
 /*
@@ -159,7 +159,7 @@ struct bio {
 #define BIO_SEG_BOUNDARY(q, b1, b2) \
 	BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
 
-#define bio_io_error(bio) bio_endio((bio), 0, bio_sectors((bio)))
+#define bio_io_error(bio) bio_endio((bio), 0)
 
 /*
  * drivers should not use the __ version unless they _really_ want to
@@ -192,7 +192,7 @@ struct bio {
 extern struct bio *bio_alloc(int, int);
 extern void bio_put(struct bio *);
 
-extern int bio_endio(struct bio *, int, int);
+extern void bio_endio(struct bio *, int);
 struct request_queue;
 extern inline int bio_phys_segments(struct request_queue *, struct bio *);
 extern inline int bio_hw_segments(struct request_queue *, struct bio *);

mm/highmem.c

@@ -288,11 +288,11 @@ static inline void copy_to_high_bio_irq(struct bio *to, struct bio *from)
 	}
 }
 
-static inline int bounce_end_io (struct bio *bio, int nr_sectors, mempool_t *pool)
+static inline void bounce_end_io(struct bio *bio, mempool_t *pool)
 {
 	struct bio *bio_orig = bio->bi_private;
 	struct bio_vec *bvec, *org_vec;
-	int ret, i;
+	int i;
 
 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
 		goto out_eio;
@@ -311,41 +311,38 @@ static inline int bounce_end_io (struct bio *bio, int nr_sectors, mempool_t *poo
 	}
 
 out_eio:
-	ret = bio_orig->bi_end_io(bio_orig, nr_sectors);
-
+	bio_orig->bi_end_io(bio_orig);
 	bio_put(bio);
-	return ret;
 }
 
-static int bounce_end_io_write(struct bio *bio, int nr_sectors)
+static void bounce_end_io_write(struct bio *bio)
 {
-	return bounce_end_io(bio, nr_sectors, page_pool);
+	bounce_end_io(bio, page_pool);
 }
 
-static int bounce_end_io_write_isa(struct bio *bio, int nr_sectors)
+static void bounce_end_io_write_isa(struct bio *bio)
 {
-	return bounce_end_io(bio, nr_sectors, isa_page_pool);
+	bounce_end_io(bio, isa_page_pool);
 }
 
-static inline int __bounce_end_io_read(struct bio *bio, int nr_sectors,
-				       mempool_t *pool)
+static inline void __bounce_end_io_read(struct bio *bio, mempool_t *pool)
 {
 	struct bio *bio_orig = bio->bi_private;
 
 	if (test_bit(BIO_UPTODATE, &bio->bi_flags))
 		copy_to_high_bio_irq(bio_orig, bio);
 
-	return bounce_end_io(bio, nr_sectors, pool);
+	bounce_end_io(bio, pool);
 }
 
-static int bounce_end_io_read(struct bio *bio, int nr_sectors)
+static void bounce_end_io_read(struct bio *bio)
 {
-	return __bounce_end_io_read(bio, nr_sectors, page_pool);
+	__bounce_end_io_read(bio, page_pool);
 }
 
-static int bounce_end_io_read_isa(struct bio *bio, int nr_sectors)
+static void bounce_end_io_read_isa(struct bio *bio)
 {
-	return __bounce_end_io_read(bio, nr_sectors, isa_page_pool);
+	return __bounce_end_io_read(bio, isa_page_pool);
 }
 
 void create_bounce(unsigned long pfn, int gfp, struct bio **bio_orig)