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author | Edward Tomasz Napierala <trasz@FreeBSD.org> | 2008-12-16 16:57:33 +0000 |
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committer | Edward Tomasz Napierala <trasz@FreeBSD.org> | 2008-12-16 16:57:33 +0000 |
commit | fa6099fda0f4866ce085895d4a552f9fa9a7c8f8 (patch) | |
tree | 4b0fd6e2cd5eb30999a8168d4c935eca7d284ac6 /sys/cam/cam_sim.c | |
parent | 96100101a8588d9f61eb13a843fb1a9574c49bdd (diff) | |
download | src-fa6099fda0f4866ce085895d4a552f9fa9a7c8f8.tar.gz src-fa6099fda0f4866ce085895d4a552f9fa9a7c8f8.zip |
Add SIM refcounting. This is slightly different from what DragonFly
does - in DragonFly, it's cam_sim_release() what actually frees the
SIM; cam_sim_free does nothing more than calling cam_sim_release().
Here, we drain in cam_sim_free, waiting for refcount to drop to zero.
We cannot do the same think DragonFly does, because after cam_sim_free
returns, client would destroy the sim->mtx, and CAM would trip over
an initialized mutex.
Reviewed by: scottl
Approved by: rwatson (mentor)
Sponsored by: FreeBSD Foundation
Notes
Notes:
svn path=/head/; revision=186185
Diffstat (limited to 'sys/cam/cam_sim.c')
-rw-r--r-- | sys/cam/cam_sim.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/sys/cam/cam_sim.c b/sys/cam/cam_sim.c index cfc20447c224..d7fcaad1afa7 100644 --- a/sys/cam/cam_sim.c +++ b/sys/cam/cam_sim.c @@ -84,6 +84,7 @@ cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, sim->max_tagged_dev_openings = max_tagged_dev_transactions; sim->max_dev_openings = max_dev_transactions; sim->flags = 0; + sim->refcount = 1; sim->devq = queue; sim->mtx = mtx; if (mtx == &Giant) { @@ -103,12 +104,40 @@ cam_sim_alloc(sim_action_func sim_action, sim_poll_func sim_poll, void cam_sim_free(struct cam_sim *sim, int free_devq) { + int error; + + sim->refcount--; + if (sim->refcount > 0) { + error = msleep(sim, sim->mtx, PRIBIO, "simfree", 0); + KASSERT(error == 0, ("invalid error value for msleep(9)")); + } + + KASSERT(sim->refcount == 0, ("sim->refcount == 0")); + if (free_devq) cam_simq_free(sim->devq); free(sim, M_CAMSIM); } void +cam_sim_release(struct cam_sim *sim) +{ + KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); + + sim->refcount--; + if (sim->refcount <= 1) + wakeup(sim); +} + +void +cam_sim_hold(struct cam_sim *sim) +{ + KASSERT(sim->refcount >= 1, ("sim->refcount >= 1")); + + sim->refcount++; +} + +void cam_sim_set_path(struct cam_sim *sim, u_int32_t path_id) { sim->path_id = path_id; |