Use scope-based cleanup helpers for kmod_dup_mutex and kmod_req to shorten the code and to clarify where the lock is taken in kmod_dup_request_exists_wait().
Signed-off-by: Petr Pavlu <[email protected]> --- kernel/module/dups.c | 56 +++++++++++++++++++++------------------------------- 1 file changed, 23 insertions(+), 33 deletions(-) diff --git a/kernel/module/dups.c b/kernel/module/dups.c index 0f6bb05b2d81..56d659f049c5 100644 --- a/kernel/module/dups.c +++ b/kernel/module/dups.c @@ -63,6 +63,8 @@ static void put_kmod_req(struct kmod_dup_req *kmod_req) kfree(kmod_req); } +DEFINE_FREE(put_kmod_req, struct kmod_dup_req *, if (_T) put_kmod_req(_T)) + static struct kmod_dup_req *kmod_dup_request_lookup(char *module_name) { struct kmod_dup_req *kmod_req; @@ -97,9 +99,8 @@ static void kmod_dup_request_delete(struct work_struct *work) * kmod. The inneficies there are a call to modprobe and modprobe * just returning 0. */ - mutex_lock(&kmod_dup_mutex); - list_del(&kmod_req->list); - mutex_unlock(&kmod_dup_mutex); + scoped_guard(mutex, &kmod_dup_mutex) + list_del(&kmod_req->list); put_kmod_req(kmod_req); } @@ -120,15 +121,18 @@ static struct kmod_dup_req *alloc_kmod_req(const char *module_name) bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret) { - struct kmod_dup_req *kmod_req; + struct kmod_dup_req *kmod_req __free(put_kmod_req) = NULL; int ret; - mutex_lock(&kmod_dup_mutex); - - kmod_req = kmod_dup_request_lookup(module_name); - if (!kmod_req) { + scoped_guard(mutex, &kmod_dup_mutex) { struct kmod_dup_req *new_kmod_req; + kmod_req = kmod_dup_request_lookup(module_name); + if (kmod_req) { + get_kmod_req(kmod_req); + break; + } + /* * If the first request that came through for a module * was with request_module_nowait() we cannot wait for it @@ -142,7 +146,6 @@ bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret) */ if (!wait) { pr_debug("New request_module_nowait() for %s -- cannot track duplicates for this request\n", module_name); - mutex_unlock(&kmod_dup_mutex); return false; } @@ -152,18 +155,12 @@ bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret) */ pr_debug("New request_module() for %s\n", module_name); new_kmod_req = alloc_kmod_req(module_name); - if (!new_kmod_req) { - mutex_unlock(&kmod_dup_mutex); + if (!new_kmod_req) return false; - } list_add(&new_kmod_req->list, &dup_kmod_reqs); - mutex_unlock(&kmod_dup_mutex); return false; } - get_kmod_req(kmod_req); - mutex_unlock(&kmod_dup_mutex); - /* We are dealing with a duplicate request now */ /* @@ -190,7 +187,7 @@ bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret) * calls bail out right away. */ *dup_ret = 0; - goto out; + return true; } /* @@ -205,14 +202,11 @@ bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret) TASK_KILLABLE); if (ret) { *dup_ret = ret; - goto out; + return true; } /* Now the duplicate request has the same exact return value as the first request */ *dup_ret = kmod_req->dup_ret; - -out: - put_kmod_req(kmod_req); return true; } @@ -220,26 +214,22 @@ void kmod_dup_request_announce(char *module_name, int ret) { struct kmod_dup_req *kmod_req; - mutex_lock(&kmod_dup_mutex); - /* * Look for a kmod_dup_req previously added in * kmod_dup_request_exists_wait(). Note that a request_module_nowait() * without its own kmod_dup_req entry can announce a result of * a concurrent request_module() call. */ - kmod_req = kmod_dup_request_lookup(module_name); - if (!kmod_req || completion_done(&kmod_req->first_req_done)) { - mutex_unlock(&kmod_dup_mutex); - return; - } - - kmod_req->dup_ret = ret; + scoped_guard(mutex, &kmod_dup_mutex) { + kmod_req = kmod_dup_request_lookup(module_name); + if (!kmod_req || completion_done(&kmod_req->first_req_done)) + return; - /* Inform all duplicate waiters to check the return value. */ - complete_all(&kmod_req->first_req_done); + kmod_req->dup_ret = ret; - mutex_unlock(&kmod_dup_mutex); + /* Inform all duplicate waiters to check the return value. */ + complete_all(&kmod_req->first_req_done); + } /* * Now that we have allowed prior request_module() calls to go on -- 2.54.0
