4.5-stable review patch. If anyone has any objections, please let me know.
------------------ From: Liu Bo <[email protected]> commit 3d8da67817606380fdadfa483d4dba5c3a5446c6 upstream. The struct 'map_lookup' uses type int for @stripe_len, while btrfs_chunk_stripe_len() can return a u64 value, and it may end up with @stripe_len being undefined value and it can lead to 'divide error' in __btrfs_map_block(). This changes 'map_lookup' to use type u64 for stripe_len, also right now we only use BTRFS_STRIPE_LEN for stripe_len, so this adds a valid checker for BTRFS_STRIPE_LEN. Reported-by: Vegard Nossum <[email protected]> Reported-by: Quentin Casasnovas <[email protected]> Signed-off-by: Liu Bo <[email protected]> Reviewed-by: David Sterba <[email protected]> [ folded division fix to scrub_raid56_parity ] Signed-off-by: David Sterba <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/btrfs/scrub.c | 2 +- fs/btrfs/volumes.c | 2 +- fs/btrfs/volumes.h | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -2858,7 +2858,7 @@ static noinline_for_stack int scrub_raid int extent_mirror_num; int stop_loop = 0; - nsectors = map->stripe_len / root->sectorsize; + nsectors = div_u64(map->stripe_len, root->sectorsize); bitmap_len = scrub_calc_parity_bitmap_len(nsectors); sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len, GFP_NOFS); --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6249,7 +6249,7 @@ static int read_one_chunk(struct btrfs_r "invalid chunk length %llu", length); return -EIO; } - if (!is_power_of_2(stripe_len)) { + if (!is_power_of_2(stripe_len) || stripe_len != BTRFS_STRIPE_LEN) { btrfs_err(root->fs_info, "invalid chunk stripe length: %llu", stripe_len); return -EIO; --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -347,7 +347,7 @@ struct map_lookup { u64 type; int io_align; int io_width; - int stripe_len; + u64 stripe_len; int sector_size; int num_stripes; int sub_stripes;
