Merge tag 'regmap-3.4' into regmap-stride

regmap: Last minute bug fix for 3.4

This is a last minute bug fix that was only just noticed since the code
path that's being exercised here is one that is fairly rarely used.  The
changelog for the change itself is extremely clear and the code itself
is obvious to inspection so should be pretty safe.

Conflicts:
	drivers/base/regmap/regmap.c (overlap between the fix and stride code)

1 files changed, 27 insertions, 6 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a872b48be0a..1411b99555a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3324,12 +3324,14 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 	stripe_size = devices_info[ndevs-1].max_avail;
 	num_stripes = ndevs * dev_stripes;
 
-	if (stripe_size * num_stripes > max_chunk_size * ncopies) {
+	if (stripe_size * ndevs > max_chunk_size * ncopies) {
 		stripe_size = max_chunk_size * ncopies;
-		do_div(stripe_size, num_stripes);
+		do_div(stripe_size, ndevs);
 	}
 
 	do_div(stripe_size, dev_stripes);
+
+	/* align to BTRFS_STRIPE_LEN */
 	do_div(stripe_size, BTRFS_STRIPE_LEN);
 	stripe_size *= BTRFS_STRIPE_LEN;
 
@@ -3805,10 +3807,11 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 		else if (mirror_num)
 			stripe_index += mirror_num - 1;
 		else {
+			int old_stripe_index = stripe_index;
 			stripe_index = find_live_mirror(map, stripe_index,
 					      map->sub_stripes, stripe_index +
 					      current->pid % map->sub_stripes);
-			mirror_num = stripe_index + 1;
+			mirror_num = stripe_index - old_stripe_index + 1;
 		}
 	} else {
 		/*
@@ -3833,6 +3836,7 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 		int sub_stripes = 0;
 		u64 stripes_per_dev = 0;
 		u32 remaining_stripes = 0;
+		u32 last_stripe = 0;
 
 		if (map->type &
 		    (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
@@ -3846,6 +3850,8 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 						      stripe_nr_orig,
 						      factor,
 						      &remaining_stripes);
+			div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
+			last_stripe *= sub_stripes;
 		}
 
 		for (i = 0; i < num_stripes; i++) {
@@ -3858,16 +3864,29 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 					 BTRFS_BLOCK_GROUP_RAID10)) {
 				bbio->stripes[i].length = stripes_per_dev *
 							  map->stripe_len;
+
 				if (i / sub_stripes < remaining_stripes)
 					bbio->stripes[i].length +=
 						map->stripe_len;
+
+				/*
+				 * Special for the first stripe and
+				 * the last stripe:
+				 *
+				 * |-------|...|-------|
+				 *     |----------|
+				 *    off     end_off
+				 */
 				if (i < sub_stripes)
 					bbio->stripes[i].length -=
 						stripe_offset;
-				if ((i / sub_stripes + 1) %
-				    sub_stripes == remaining_stripes)
+
+				if (stripe_index >= last_stripe &&
+				    stripe_index <= (last_stripe +
+						     sub_stripes - 1))
 					bbio->stripes[i].length -=
 						stripe_end_offset;
+
 				if (i == sub_stripes - 1)
 					stripe_offset = 0;
 			} else
@@ -4334,8 +4353,10 @@ static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
 
 	ret = __btrfs_open_devices(fs_devices, FMODE_READ,
 				   root->fs_info->bdev_holder);
-	if (ret)
+	if (ret) {
+		free_fs_devices(fs_devices);
 		goto out;
+	}
 
 	if (!fs_devices->seeding) {
 		__btrfs_close_devices(fs_devices);