Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0ef6447a authored by Feifei Xu's avatar Feifei Xu Committed by David Sterba
Browse files

Btrfs: Fix integer overflow when calculating bytes_per_bitmap 



On ppc64, bytes_per_bitmap will be (65536*8*65536). Hence append UL to
fix integer overflow.

Reviewed-by: default avatarJosef Bacik <jbacik@fb.com>
Reviewed-by: default avatarChandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: default avatarFeifei Xu <xufeifei@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 5473e0c4

fs/btrfs/free-space-cache.c

+6 −6
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ 
#include "inode-map.h"

#include "volumes.h"



#define BITS_PER_BITMAP		(PAGE_SIZE * 8)

#define BITS_PER_BITMAP		(PAGE_SIZE * 8UL)

#define MAX_CACHE_BYTES_PER_GIG	SZ_32K



struct btrfs_trim_range {
@@ -1415,11 +1415,11 @@ static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl, 
				   u64 offset)

{

	u64 bitmap_start;

	u32 bytes_per_bitmap;

	u64 bytes_per_bitmap;



	bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;

	bitmap_start = offset - ctl->start;

	bitmap_start = div_u64(bitmap_start, bytes_per_bitmap);

	bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);

	bitmap_start *= bytes_per_bitmap;

	bitmap_start += ctl->start;
@@ -1638,10 +1638,10 @@ static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl) 
	u64 bitmap_bytes;

	u64 extent_bytes;

	u64 size = block_group->key.offset;

	u32 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;

	u32 max_bitmaps = div_u64(size + bytes_per_bg - 1, bytes_per_bg);

	u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;

	u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);



	max_bitmaps = max_t(u32, max_bitmaps, 1);

	max_bitmaps = max_t(u64, max_bitmaps, 1);



	ASSERT(ctl->total_bitmaps <= max_bitmaps);

fs/btrfs/tests/free-space-tests.c

+1 −1
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ 
#include "../disk-io.h"

#include "../free-space-cache.h"



#define BITS_PER_BITMAP		(PAGE_SIZE * 8)

#define BITS_PER_BITMAP		(PAGE_SIZE * 8UL)



/*

 * This test just does basic sanity checking, making sure we can add an extent