diff options
author | Li Zefan <lizefan@huawei.com> | 2013-08-01 09:51:47 +0800 |
---|---|---|
committer | Tejun Heo <tj@kernel.org> | 2013-08-01 09:29:41 -0400 |
commit | 876ede8b2b9880615be0de3ec7b8afd0a1786e76 (patch) | |
tree | b2c238a5939a6daf9f43b6eba1b1ceaf3dc2c372 /kernel/cgroup.c | |
parent | e14880f7bb7e0dc0933af304998371dd543ceb40 (diff) | |
download | linux-876ede8b2b9880615be0de3ec7b8afd0a1786e76.tar.bz2 |
cgroup: restructure the failure path in cgroup_write_event_control()
It uses a single label and checks the validity of each pointer. This
is err-prone, and actually we had a bug because one of the check was
insufficient.
Use multi lables as we do in other places.
v2:
- drop initializations of local variables.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r-- | kernel/cgroup.c | 39 |
1 files changed, 18 insertions, 21 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 3f6593333525..9f6dab22289e 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3934,11 +3934,11 @@ static void cgroup_event_ptable_queue_proc(struct file *file, static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, const char *buffer) { - struct cgroup_event *event = NULL; + struct cgroup_event *event; struct cgroup *cgrp_cfile; unsigned int efd, cfd; - struct file *efile = NULL; - struct file *cfile = NULL; + struct file *efile; + struct file *cfile; char *endp; int ret; @@ -3964,31 +3964,31 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, efile = eventfd_fget(efd); if (IS_ERR(efile)) { ret = PTR_ERR(efile); - goto fail; + goto out_kfree; } event->eventfd = eventfd_ctx_fileget(efile); if (IS_ERR(event->eventfd)) { ret = PTR_ERR(event->eventfd); - goto fail; + goto out_put_efile; } cfile = fget(cfd); if (!cfile) { ret = -EBADF; - goto fail; + goto out_put_eventfd; } /* the process need read permission on control file */ /* AV: shouldn't we check that it's been opened for read instead? */ ret = inode_permission(file_inode(cfile), MAY_READ); if (ret < 0) - goto fail; + goto out_put_cfile; event->cft = __file_cft(cfile); if (IS_ERR(event->cft)) { ret = PTR_ERR(event->cft); - goto fail; + goto out_put_cfile; } /* @@ -3998,18 +3998,18 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, cgrp_cfile = __d_cgrp(cfile->f_dentry->d_parent); if (cgrp_cfile != cgrp) { ret = -EINVAL; - goto fail; + goto out_put_cfile; } if (!event->cft->register_event || !event->cft->unregister_event) { ret = -EINVAL; - goto fail; + goto out_put_cfile; } ret = event->cft->register_event(cgrp, event->cft, event->eventfd, buffer); if (ret) - goto fail; + goto out_put_cfile; efile->f_op->poll(efile, &event->pt); @@ -4029,16 +4029,13 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, return 0; -fail: - if (cfile) - fput(cfile); - - if (event && event->eventfd && !IS_ERR(event->eventfd)) - eventfd_ctx_put(event->eventfd); - - if (!IS_ERR_OR_NULL(efile)) - fput(efile); - +out_put_cfile: + fput(cfile); +out_put_eventfd: + eventfd_ctx_put(event->eventfd); +out_put_efile: + fput(efile); +out_kfree: kfree(event); return ret; |