Author: bz Date: Fri Sep 4 18:18:05 2020 New Revision: 365333 URL: https://svnweb.freebsd.org/changeset/base/365333
Log: 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. Reviewed by: imp; no-objections by: mav MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D26286 Modified: head/sys/cam/cam_sim.c Modified: head/sys/cam/cam_sim.c ============================================================================== --- head/sys/cam/cam_sim.c Fri Sep 4 17:37:58 2020 (r365332) +++ head/sys/cam/cam_sim.c Fri Sep 4 18:18:05 2020 (r365333) @@ -124,14 +124,15 @@ cam_sim_alloc_dev(sim_action_func sim_action, sim_poll 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) { @@ -139,7 +140,7 @@ 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) @@ -150,17 +151,16 @@ 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) @@ -172,17 +172,16 @@ 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) _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
