Messages in this thread | | | From | (Eric W. Biederman) | Date | Tue, 08 Oct 2013 13:31:45 -0700 | Subject | Re: [RFC][PATCH 1/3] vfs: Keep a list of mounts on a mount point |
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Miklos Szeredi <miklos@szeredi.hu> writes:
>> @@ -691,6 +693,7 @@ static void detach_mnt(struct mount *mnt, struct path *old_path) >> list_del_init(&mnt->mnt_hash); >> put_mountpoint(mnt->mnt_mp); >> mnt->mnt_mp = NULL; >> + list_del_init(&mnt->mnt_mp_list); > > Should be done *before* put_mountpoint(), for obvious reasons. > > And a BUG_ON(!list_empty(&mp->m_list)) in put_mountpoint() for good measure (and > no, WARN_ON() is not better here, since use-after-free is definitely worse than > a BUG).
Good point. I will take a look at making this change shortly and repost the patches.
>> } >> >> /* >> @@ -705,6 +708,7 @@ void mnt_set_mountpoint(struct mount *mnt, >> child_mnt->mnt_mountpoint = dget(mp->m_dentry); >> child_mnt->mnt_parent = mnt; >> child_mnt->mnt_mp = mp; >> + list_add_tail(&child_mnt->mnt_mp_list, &mp->m_list); >> } >> >> /* >> @@ -1193,6 +1197,7 @@ void umount_tree(struct mount *mnt, int propagate) >> p->mnt_parent->mnt_ghosts++; >> put_mountpoint(p->mnt_mp); >> p->mnt_mp = NULL; >> + list_del_init(&mnt->mnt_mp_list); > > Ditto. > >> } >> change_mnt_propagation(p, MS_PRIVATE); >> } >> -- >> 1.7.5.4 >>
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