From 3d8da67817606380fdadfa483d4dba5c3a5446c6 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Tue, 26 Apr 2016 17:53:31 -0700 Subject: [PATCH] Btrfs: fix divide error upon chunk's stripe_len 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 Reported-by: Quentin Casasnovas Signed-off-by: Liu Bo Reviewed-by: David Sterba [ folded division fix to scrub_raid56_parity ] Signed-off-by: David Sterba --- fs/btrfs/scrub.c | 2 +- fs/btrfs/volumes.c | 2 +- fs/btrfs/volumes.h | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 2ff2876656ba..96d2a0de35a8 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -2860,7 +2860,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx, 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); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 7bd553d42e0d..f13e2bcc1398 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6254,7 +6254,7 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key, "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; diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 1939ebde63df..7507be74f7da 100644 --- 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;