[PATCH] btrfs: Fix -Wunused-but-set-variable warnings

[Andrey Abramov]

Fix -Wunused-but-set-variable warnings in raid56.c and sysfs.c files

Signed-off-by: Andrey Abramov <st5pub@xxxxxxxxx>
---
 fs/btrfs/raid56.c | 32 +++++++++++---------------------
 fs/btrfs/sysfs.c  |  5 +----
 2 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index f3d0576dd327..4ab29eacfdf3 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1182,22 +1182,17 @@ static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
 	int nr_data = rbio->nr_data;
 	int stripe;
 	int pagenr;
-	int p_stripe = -1;
-	int q_stripe = -1;
+	int is_q_stripe = 0;
 	struct bio_list bio_list;
 	struct bio *bio;
 	int ret;
 
 	bio_list_init(&bio_list);
 
-	if (rbio->real_stripes - rbio->nr_data == 1) {
-		p_stripe = rbio->real_stripes - 1;
-	} else if (rbio->real_stripes - rbio->nr_data == 2) {
-		p_stripe = rbio->real_stripes - 2;
-		q_stripe = rbio->real_stripes - 1;
-	} else {
+	if (rbio->real_stripes - rbio->nr_data == 2)
+		is_q_stripe = 1;
+	else if (rbio->real_stripes - rbio->nr_data != 1)
 		BUG();
-	}
 
 	/* at this point we either have a full stripe,
 	 * or we've read the full stripe from the drive.
@@ -1241,7 +1236,7 @@ static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
 		SetPageUptodate(p);
 		pointers[stripe++] = kmap(p);
 
-		if (q_stripe != -1) {
+		if (is_q_stripe) {
 
 			/*
 			 * raid6, add the qstripe and call the
@@ -2340,8 +2335,7 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
 	int nr_data = rbio->nr_data;
 	int stripe;
 	int pagenr;
-	int p_stripe = -1;
-	int q_stripe = -1;
+	int is_q_stripe = 0;
 	struct page *p_page = NULL;
 	struct page *q_page = NULL;
 	struct bio_list bio_list;
@@ -2351,14 +2345,10 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
 
 	bio_list_init(&bio_list);
 
-	if (rbio->real_stripes - rbio->nr_data == 1) {
-		p_stripe = rbio->real_stripes - 1;
-	} else if (rbio->real_stripes - rbio->nr_data == 2) {
-		p_stripe = rbio->real_stripes - 2;
-		q_stripe = rbio->real_stripes - 1;
-	} else {
+	if (rbio->real_stripes - rbio->nr_data == 2)
+		is_q_stripe = 1;
+	else if (rbio->real_stripes - rbio->nr_data != 1)
 		BUG();
-	}
 
 	if (bbio->num_tgtdevs && bbio->tgtdev_map[rbio->scrubp]) {
 		is_replace = 1;
@@ -2380,7 +2370,7 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
 		goto cleanup;
 	SetPageUptodate(p_page);
 
-	if (q_stripe != -1) {
+	if (is_q_stripe) {
 		q_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
 		if (!q_page) {
 			__free_page(p_page);
@@ -2403,7 +2393,7 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
 		/* then add the parity stripe */
 		pointers[stripe++] = kmap(p_page);
 
-		if (q_stripe != -1) {
+		if (is_q_stripe) {
 
 			/*
 			 * raid6, add the qstripe and call the
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 2f078b77fe14..514b75dec4a9 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -887,13 +887,10 @@ void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
 {
 	struct btrfs_fs_devices *fs_devs;
 	struct kobject *fsid_kobj;
-	u64 features;
-	int ret;
 
 	if (!fs_info)
 		return;
 
-	features = get_features(fs_info, set);
 	ASSERT(bit & supported_feature_masks[set]);
 
 	fs_devs = fs_info->fs_devices;
@@ -907,7 +904,7 @@ void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
 	 * to use sysfs_update_group but some refactoring is needed first.
 	 */
 	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
-	ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
+	sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
 }
 
 static int btrfs_init_debugfs(void)
-- 
2.20.1