Messages in this thread | | | From | Filipe Manana <> | Date | Sat, 7 Dec 2019 17:16:10 +0000 | Subject | Re: [PATCH] fs: Fix a missing check bug |
| |
On Sat, Dec 7, 2019 at 3:03 PM Dinghao Liu <dinghao.liu@zju.edu.cn> wrote: > > The return value of link_free_space(ctl, info) is checked out-sync. Only one branch of an if statement checks this return value after WARN_ON(ret). > > Since this path pair is similar in semantic, there might be a missing check bug. > > Fix this by simply adding a check on ret. > > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > --- > fs/btrfs/free-space-cache.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c > index 3283da419200..acbb3a59d344 100644 > --- a/fs/btrfs/free-space-cache.c > +++ b/fs/btrfs/free-space-cache.c > @@ -2437,6 +2437,8 @@ int btrfs_remove_free_space(struct btrfs_block_group *block_group, > if (info->bytes) { > ret = link_free_space(ctl, info); > WARN_ON(ret); > + if (ret)
I think the WARN_ON() can go away as well. The only possible error is -EEXIST, coming from tree_insert_offset(). When that happens tree_insert_offset() already emits a warning.
Also, the free space entry needs to be freed, otherwise we leak memory. So it should be something like this:
if (ret) { kmem_cache_free(btrfs_free_space_cachep, info); goto out_unlock; }
Further the subject should be prefixed with "btrfs: " and not "fs: ", since this is a btrfs specific patch. Something like the following for example:
"btrfs: add missing error handling when removing free space"
Thanks.
> + goto out_lock; > } else { > kmem_cache_free(btrfs_free_space_cachep, info); > } > -- > 2.21.0 (Apple Git-122) >
-- Filipe David Manana,
“Whether you think you can, or you think you can't — you're right.”
| |