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authorZhangXiaoxu <zhangxiaoxu5@huawei.com>2019-08-17 13:32:40 +0800
committerMike Snitzer <snitzer@redhat.com>2019-08-22 16:11:23 -0400
commite4f9d6013820d1eba1432d51dd1c5795759aa77f (patch)
treee7d3f420754a270eb34f67d6af0187909821aba9
parentdc1a3e8e0cc6b2293b48c044710e63395aeb4fb4 (diff)
downloadlinux-e4f9d6013820d1eba1432d51dd1c5795759aa77f.tar.bz2
dm btree: fix order of block initialization in btree_split_beneath
When btree_split_beneath() splits a node to two new children, it will allocate two blocks: left and right. If right block's allocation failed, the left block will be unlocked and marked dirty. If this happened, the left block'ss content is zero, because it wasn't initialized with the btree struct before the attempot to allocate the right block. Upon return, when flushing the left block to disk, the validator will fail when check this block. Then a BUG_ON is raised. Fix this by completely initializing the left block before allocating and initializing the right block. Fixes: 4dcb8b57df359 ("dm btree: fix leak of bufio-backed block in btree_split_beneath error path") Cc: stable@vger.kernel.org Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
-rw-r--r--drivers/md/persistent-data/dm-btree.c31
1 files changed, 16 insertions, 15 deletions
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index 58b319757b1e..8aae0624a297 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -628,39 +628,40 @@ static int btree_split_beneath(struct shadow_spine *s, uint64_t key)
new_parent = shadow_current(s);
+ pn = dm_block_data(new_parent);
+ size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ?
+ sizeof(__le64) : s->info->value_type.size;
+
+ /* create & init the left block */
r = new_block(s->info, &left);
if (r < 0)
return r;
+ ln = dm_block_data(left);
+ nr_left = le32_to_cpu(pn->header.nr_entries) / 2;
+
+ ln->header.flags = pn->header.flags;
+ ln->header.nr_entries = cpu_to_le32(nr_left);
+ ln->header.max_entries = pn->header.max_entries;
+ ln->header.value_size = pn->header.value_size;
+ memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0]));
+ memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size);
+
+ /* create & init the right block */
r = new_block(s->info, &right);
if (r < 0) {
unlock_block(s->info, left);
return r;
}
- pn = dm_block_data(new_parent);
- ln = dm_block_data(left);
rn = dm_block_data(right);
-
- nr_left = le32_to_cpu(pn->header.nr_entries) / 2;
nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left;
- ln->header.flags = pn->header.flags;
- ln->header.nr_entries = cpu_to_le32(nr_left);
- ln->header.max_entries = pn->header.max_entries;
- ln->header.value_size = pn->header.value_size;
-
rn->header.flags = pn->header.flags;
rn->header.nr_entries = cpu_to_le32(nr_right);
rn->header.max_entries = pn->header.max_entries;
rn->header.value_size = pn->header.value_size;
-
- memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0]));
memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0]));
-
- size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ?
- sizeof(__le64) : s->info->value_type.size;
- memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size);
memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left),
nr_right * size);