btrfs: fix remaining u32 overflows when left shifting stripe_nr

There was regression caused by a97699d1d610 ("btrfs: replace
map_lookup->stripe_len by BTRFS_STRIPE_LEN") and supposedly fixed by
a7299a18a179 ("btrfs: fix u32 overflows when left shifting stripe_nr").
To avoid code churn the fix was open coding the type casts but
unfortunately missed one which was still possible to hit [1].

The missing place was assignment of bioc->full_stripe_logical inside
btrfs_map_block().

Fix it by adding a helper that does the safe calculation of the offset
and use it everywhere even though it may not be strictly necessary due
to already using u64 types.  This replaces all remaining
"<< BTRFS_STRIPE_LEN_SHIFT" calls.

[1] https://lore.kernel.org/linux-btrfs/20230622065438.86402-1-wqu@suse.com/

Fixes: a7299a18a179 ("btrfs: fix u32 overflows when left shifting stripe_nr")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 11 insertions, 11 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index bceaa8c2007e..16c228344cbb 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1304,7 +1304,7 @@ static int get_raid56_logic_offset(u64 physical, int num,
 		u32 stripe_index;
 		u32 rot;
 
-		*offset = last_offset + (i << BTRFS_STRIPE_LEN_SHIFT);
+		*offset = last_offset + btrfs_stripe_nr_to_offset(i);
 
 		stripe_nr = (u32)(*offset >> BTRFS_STRIPE_LEN_SHIFT) / data_stripes;
 
@@ -1319,7 +1319,7 @@ static int get_raid56_logic_offset(u64 physical, int num,
 		if (stripe_index < num)
 			j++;
 	}
-	*offset = last_offset + (j << BTRFS_STRIPE_LEN_SHIFT);
+	*offset = last_offset + btrfs_stripe_nr_to_offset(j);
 	return 1;
 }
 
@@ -1715,7 +1715,7 @@ static int flush_scrub_stripes(struct scrub_ctx *sctx)
 	ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &sctx->stripes[0].state));
 
 	scrub_throttle_dev_io(sctx, sctx->stripes[0].dev,
-			      nr_stripes << BTRFS_STRIPE_LEN_SHIFT);
+			      btrfs_stripe_nr_to_offset(nr_stripes));
 	for (int i = 0; i < nr_stripes; i++) {
 		stripe = &sctx->stripes[i];
 		scrub_submit_initial_read(sctx, stripe);
@@ -1838,7 +1838,7 @@ static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx,
 	bool all_empty = true;
 	const int data_stripes = nr_data_stripes(map);
 	unsigned long extent_bitmap = 0;
-	u64 length = data_stripes << BTRFS_STRIPE_LEN_SHIFT;
+	u64 length = btrfs_stripe_nr_to_offset(data_stripes);
 	int ret;
 
 	ASSERT(sctx->raid56_data_stripes);
@@ -1853,13 +1853,13 @@ static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx,
 			      data_stripes) >> BTRFS_STRIPE_LEN_SHIFT;
 		stripe_index = (i + rot) % map->num_stripes;
 		physical = map->stripes[stripe_index].physical +
-			   (rot << BTRFS_STRIPE_LEN_SHIFT);
+			   btrfs_stripe_nr_to_offset(rot);
 
 		scrub_reset_stripe(stripe);
 		set_bit(SCRUB_STRIPE_FLAG_NO_REPORT, &stripe->state);
 		ret = scrub_find_fill_first_stripe(bg,
 				map->stripes[stripe_index].dev, physical, 1,
-				full_stripe_start + (i << BTRFS_STRIPE_LEN_SHIFT),
+				full_stripe_start + btrfs_stripe_nr_to_offset(i),
 				BTRFS_STRIPE_LEN, stripe);
 		if (ret < 0)
 			goto out;
@@ -1869,7 +1869,7 @@ static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx,
 		 */
 		if (ret > 0) {
 			stripe->logical = full_stripe_start +
-					  (i << BTRFS_STRIPE_LEN_SHIFT);
+					  btrfs_stripe_nr_to_offset(i);
 			stripe->dev = map->stripes[stripe_index].dev;
 			stripe->mirror_num = 1;
 			set_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state);
@@ -2062,7 +2062,7 @@ static u64 simple_stripe_full_stripe_len(const struct map_lookup *map)
 	ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
 			    BTRFS_BLOCK_GROUP_RAID10));
 
-	return (map->num_stripes / map->sub_stripes) << BTRFS_STRIPE_LEN_SHIFT;
+	return btrfs_stripe_nr_to_offset(map->num_stripes / map->sub_stripes);
 }
 
 /* Get the logical bytenr for the stripe */
@@ -2078,7 +2078,7 @@ static u64 simple_stripe_get_logical(struct map_lookup *map,
 	 * (stripe_index / sub_stripes) gives how many data stripes we need to
 	 * skip.
 	 */
-	return ((stripe_index / map->sub_stripes) << BTRFS_STRIPE_LEN_SHIFT) +
+	return btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes) +
 	       bg->start;
 }
 
@@ -2204,7 +2204,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	}
 	if (profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
 		ret = scrub_simple_stripe(sctx, bg, map, scrub_dev, stripe_index);
-		offset = (stripe_index / map->sub_stripes) << BTRFS_STRIPE_LEN_SHIFT;
+		offset = btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes);
 		goto out;
 	}
 
@@ -2219,7 +2219,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 
 	/* Initialize @offset in case we need to go to out: label */
 	get_raid56_logic_offset(physical, stripe_index, map, &offset, NULL);
-	increment = nr_data_stripes(map) << BTRFS_STRIPE_LEN_SHIFT;
+	increment = btrfs_stripe_nr_to_offset(nr_data_stripes(map));
 
 	/*
 	 * Due to the rotation, for RAID56 it's better to iterate each stripe