Author: bz
Date: Thu Nov 5 11:19:31 2020
New Revision: 367367
URL: https://svnweb.freebsd.org/changeset/base/367367
Log:
MFC r365333:
cam_sim: harmonize code related to acquiring a mtx
cam_sim_free(), cam_sim_release(), and cam_sim_hold() all assign
a mtx variable during declaration and then if NULL or the mtx is
held may re-asign the variable and/or acquire/release a lock.
Harmonize the code, avoiding double assignments and make it look
the same for all three function (with cam_sim_free() not needing
an extra case).
No functional changes intended.
Modified:
stable/12/sys/cam/cam_sim.c
Directory Properties:
stable/12/ (props changed)
Modified: stable/12/sys/cam/cam_sim.c
==============================================================================
--- stable/12/sys/cam/cam_sim.c Thu Nov 5 11:11:50 2020 (r367366)
+++ stable/12/sys/cam/cam_sim.c Thu Nov 5 11:19:31 2020 (r367367)
@@ -103,14 +103,15 @@ cam_sim_alloc(sim_action_func sim_action, sim_poll_fun
void
cam_sim_free(struct cam_sim *sim, int free_devq)
{
- struct mtx *mtx = sim->mtx;
+ struct mtx *mtx;
int error;
- if (mtx) {
- mtx_assert(mtx, MA_OWNED);
- } else {
+ if (sim->mtx == NULL) {
mtx = &cam_sim_free_mtx;
mtx_lock(mtx);
+ } else {
+ mtx = sim->mtx;
+ mtx_assert(mtx, MA_OWNED);
}
sim->refcount--;
if (sim->refcount > 0) {
@@ -118,7 +119,7 @@ cam_sim_free(struct cam_sim *sim, int free_devq)
KASSERT(error == 0, ("invalid error value for msleep(9)"));
}
KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
- if (sim->mtx == NULL)
+ if (mtx == &cam_sim_free_mtx) /* sim->mtx == NULL */
mtx_unlock(mtx);
if (free_devq)
@@ -129,17 +130,16 @@ cam_sim_free(struct cam_sim *sim, int free_devq)
void
cam_sim_release(struct cam_sim *sim)
{
- struct mtx *mtx = sim->mtx;
+ struct mtx *mtx;
- if (mtx) {
- if (!mtx_owned(mtx))
- mtx_lock(mtx);
- else
- mtx = NULL;
- } else {
+ if (sim->mtx == NULL)
mtx = &cam_sim_free_mtx;
+ else if (!mtx_owned(sim->mtx))
+ mtx = sim->mtx;
+ else
+ mtx = NULL; /* We hold the lock. */
+ if (mtx)
mtx_lock(mtx);
- }
KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
sim->refcount--;
if (sim->refcount == 0)
@@ -151,17 +151,16 @@ cam_sim_release(struct cam_sim *sim)
void
cam_sim_hold(struct cam_sim *sim)
{
- struct mtx *mtx = sim->mtx;
+ struct mtx *mtx;
- if (mtx) {
- if (!mtx_owned(mtx))
- mtx_lock(mtx);
- else
- mtx = NULL;
- } else {
+ if (sim->mtx == NULL)
mtx = &cam_sim_free_mtx;
+ else if (!mtx_owned(sim->mtx))
+ mtx = sim->mtx;
+ else
+ mtx = NULL; /* We hold the lock. */
+ if (mtx)
mtx_lock(mtx);
- }
KASSERT(sim->refcount >= 1, ("sim->refcount >= 1"));
sim->refcount++;
if (mtx)
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