Re: [PATCH] fs: fix: second lock in function d_prune_aliases().

From: Li, Hao
Date: Wed Dec 30 2020 - 03:28:40 EST


On 2020/12/30 15:01, YANG LI wrote:
> Goto statement jumping will cause lock to be executed again without
> executing unlock, placing the lock statement in front of goto
> label to fix this problem.
>
> Signed-off-by: YANG LI <abaci-bugfix@xxxxxxxxxxxxxxxxx>
> Reported-by: Abaci <abaci@xxxxxxxxxxxxxxxxx>
> ---
>  fs/dcache.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/dcache.c b/fs/dcache.c
> index 97e81a8..bf38446 100644
> --- a/fs/dcache.c
> +++ b/fs/dcache.c
> @@ -1050,6 +1050,6 @@ void d_prune_aliases(struct inode *inode)
>  {
>      struct dentry *dentry;
> -restart:
>      spin_lock(&inode->i_lock);

This inode lock should be released at __dentry_kill->dentry_unlink_inode.

Regards,
Hao Lee

>
> +restart:
>      hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
>          spin_lock(&dentry->d_lock);