md/raid1: Clean up local variable 'b' from raid1_read_request()

The local variable will only be used onced, in the error path that
read_balance() failed to find a valid rdev to read. Since now the rdev
is ensured can't be removed from conf while IO is still pending,
remove the local variable and dereference rdev directly.

Since we're here, also remove an extra empty line, and unnecessary
type conversion from sector_t(u64) to unsigned long long.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240801133008.459998-1-yukuai1@huaweicloud.comSigned-off-by: Song Liu <song@kernel.org>

drivers/md/raid1.c

@@ -1317,7 +1317,6 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 	int max_sectors;
 	int rdisk;
 	bool r1bio_existed = !!r1_bio;
-	char b[BDEVNAME_SIZE];
 
 	/*
 	 * If r1_bio is set, we are blocking the raid1d thread
@@ -1326,16 +1325,6 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 	 */
 	gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
 
-	if (r1bio_existed) {
-		/* Need to get the block device name carefully */
-		struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
-
-		if (rdev)
-			snprintf(b, sizeof(b), "%pg", rdev->bdev);
-		else
-			strcpy(b, "???");
-	}
-
 	/*
 	 * Still need barrier for READ in case that whole
 	 * array is frozen.
@@ -1357,15 +1346,13 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 	 * used and no empty request is available.
 	 */
 	rdisk = read_balance(conf, r1_bio, &max_sectors);
-
 	if (rdisk < 0) {
 		/* couldn't find anywhere to read from */
-		if (r1bio_existed) {
-			pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
+		if (r1bio_existed)
+			pr_crit_ratelimited("md/raid1:%s: %pg: unrecoverable I/O read error for block %llu\n",
 					    mdname(mddev),
-					    b,
-					    (unsigned long long)r1_bio->sector);
-		}
+					    conf->mirrors[r1_bio->read_disk].rdev->bdev,
+					    r1_bio->sector);
 		raid_end_bio_io(r1_bio);
 		return;
 	}