On 25/01/16 09:11, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <n...@linux-iscsi.org>
>
> Cc: Juergen Gross <jgr...@suse.com>
> Cc: Hannes Reinecke <h...@suse.de>
> Cc: David Vrabel <david.vra...@citrix.com>
> Signed-off-by: Nicholas Bellinger <n...@linux-iscsi.org>
> ---
> drivers/xen/xen-scsiback.c | 163
> ++++++++++++++++++++++++---------------------
> 1 file changed, 87 insertions(+), 76 deletions(-)
>
> diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
> index 594f8a7..640fb22 100644
> --- a/drivers/xen/xen-scsiback.c
> +++ b/drivers/xen/xen-scsiback.c
> @@ -190,7 +190,6 @@ module_param_named(max_buffer_pages,
> scsiback_max_buffer_pages, int, 0644);
> MODULE_PARM_DESC(max_buffer_pages,
> "Maximum number of free pages to keep in backend buffer");
>
> -static struct kmem_cache *scsiback_cachep;
> static DEFINE_SPINLOCK(free_pages_lock);
> static int free_pages_num;
> static LIST_HEAD(scsiback_free_pages);
> @@ -322,7 +321,8 @@ static void scsiback_free_translation_entry(struct kref
> *kref)
> }
>
> static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
> - uint32_t resid, struct vscsibk_pend *pending_req)
> + uint32_t resid, struct vscsibk_pend *pending_req,
> + uint16_t rqid)
> {
> struct vscsiif_response *ring_res;
> struct vscsibk_info *info = pending_req->info;
pending_req might be NULL now, so this will panic the system.
Juergen
> @@ -337,7 +337,7 @@ static void scsiback_do_resp_with_sense(char
> *sense_buffer, int32_t result,
> info->ring.rsp_prod_pvt++;
>
> ring_res->rslt = result;
> - ring_res->rqid = pending_req->rqid;
> + ring_res->rqid = rqid;
>
> if (sense_buffer != NULL &&
> scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
> @@ -358,7 +358,7 @@ static void scsiback_do_resp_with_sense(char
> *sense_buffer, int32_t result,
> if (notify)
> notify_remote_via_irq(info->irq);
>
> - if (pending_req->v2p)
> + if (pending_req && pending_req->v2p)
> kref_put(&pending_req->v2p->kref,
> scsiback_free_translation_entry);
> }
> @@ -378,7 +378,8 @@ static void scsiback_cmd_done(struct vscsibk_pend
> *pending_req)
> scsiback_print_status(sense_buffer, errors, pending_req);
>
> scsiback_fast_flush_area(pending_req);
> - scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
> + scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req,
> + pending_req->rqid);
> scsiback_put(info);
> }
>
> @@ -616,15 +617,15 @@ static void scsiback_device_action(struct vscsibk_pend
> *pending_req,
> err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
> SUCCESS : FAILED;
>
> -out:
> - if (tmr) {
> - transport_generic_free_cmd(&pending_req->se_cmd, 1);
> + scsiback_do_resp_with_sense(NULL, err, 0, pending_req,
> + pending_req->rqid);
> + transport_generic_free_cmd(&pending_req->se_cmd, 1);
> + return;
> +err:
> + if (tmr)
> kfree(tmr);
> - }
> -
> - scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
> -
> - kmem_cache_free(scsiback_cachep, pending_req);
> + scsiback_do_resp_with_sense(NULL, err, 0, pending_req,
> + pending_req->rqid);
> }
>
> /*
> @@ -653,15 +654,53 @@ out:
> return entry;
> }
>
> -static int prepare_pending_reqs(struct vscsibk_info *info,
> - struct vscsiif_request *ring_req,
> - struct vscsibk_pend *pending_req)
> +static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring
> *ring,
> + struct v2p_entry *v2p)
> +{
> + struct scsiback_tpg *tpg = v2p->tpg;
> + struct scsiback_nexus *nexus = tpg->tpg_nexus;
> + struct se_session *se_sess = nexus->tvn_se_sess;
> + struct vscsibk_pend *req;
> + int tag, i;
> +
> + tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
> + if (tag < 0) {
> + pr_err("Unable to obtain tag for vscsiif_request\n");
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
> + memset(req, 0, sizeof(*req));
> + req->se_cmd.map_tag = tag;
> +
> + for (i = 0; i < VSCSI_MAX_GRANTS; i++)
> + req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
> +
> + return req;
> +}
> +
> +static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
> + struct vscsiif_back_ring *ring,
> + struct vscsiif_request *ring_req)
> {
> + struct vscsibk_pend *pending_req;
> struct v2p_entry *v2p;
> struct ids_tuple vir;
>
> - pending_req->rqid = ring_req->rqid;
> - pending_req->info = info;
> + /* request range check from frontend */
> + if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
> + (ring_req->sc_data_direction != DMA_TO_DEVICE) &&
> + (ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
> + (ring_req->sc_data_direction != DMA_NONE)) {
> + pr_debug("invalid parameter data_dir = %d\n",
> + ring_req->sc_data_direction);
> + return ERR_PTR(-EINVAL);
> + }
> + if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
> + pr_debug("invalid parameter cmd_len = %d\n",
> + ring_req->cmd_len);
> + return ERR_PTR(-EINVAL);
> + }
>
> vir.chn = ring_req->channel;
> vir.tgt = ring_req->id;
> @@ -669,33 +708,24 @@ static int prepare_pending_reqs(struct vscsibk_info
> *info,
>
> v2p = scsiback_do_translation(info, &vir);
> if (!v2p) {
> - pending_req->v2p = NULL;
> pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
> - vir.chn, vir.tgt, vir.lun);
> - return -ENODEV;
> + vir.chn, vir.tgt, vir.lun);
> + return ERR_PTR(-ENODEV);
> }
> - pending_req->v2p = v2p;
>
> - /* request range check from frontend */
> - pending_req->sc_data_direction = ring_req->sc_data_direction;
> - if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
> - (pending_req->sc_data_direction != DMA_TO_DEVICE) &&
> - (pending_req->sc_data_direction != DMA_FROM_DEVICE) &&
> - (pending_req->sc_data_direction != DMA_NONE)) {
> - pr_debug("invalid parameter data_dir = %d\n",
> - pending_req->sc_data_direction);
> - return -EINVAL;
> + pending_req = scsiback_get_pend_req(ring, v2p);
> + if (IS_ERR(pending_req)) {
> + kref_put(&v2p->kref, scsiback_free_translation_entry);
> + return ERR_PTR(-ENOMEM);
> }
> -
> + pending_req->rqid = ring_req->rqid;
> + pending_req->info = info;
> + pending_req->v2p = v2p;
> + pending_req->sc_data_direction = ring_req->sc_data_direction;
> pending_req->cmd_len = ring_req->cmd_len;
> - if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
> - pr_debug("invalid parameter cmd_len = %d\n",
> - pending_req->cmd_len);
> - return -EINVAL;
> - }
> memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
>
> - return 0;
> + return pending_req;
> }
>
> static int scsiback_do_cmd_fn(struct vscsibk_info *info)
> @@ -704,7 +734,7 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
> struct vscsiif_request ring_req;
> struct vscsibk_pend *pending_req;
> RING_IDX rc, rp;
> - int err, more_to_do;
> + int more_to_do;
> uint32_t result;
>
> rc = ring->req_cons;
> @@ -722,16 +752,13 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
> while ((rc != rp)) {
> if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
> break;
> - pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
> - if (!pending_req)
> - return 1;
>
> ring_req = *RING_GET_REQUEST(ring, rc);
> ring->req_cons = ++rc;
>
> - err = prepare_pending_reqs(info, &ring_req, pending_req);
> - if (err) {
> - switch (err) {
> + pending_req = prepare_pending_reqs(info, ring, &ring_req);
> + if (IS_ERR(pending_req)) {
> + switch (PTR_ERR(pending_req)) {
> case -ENODEV:
> result = DID_NO_CONNECT;
> break;
> @@ -739,9 +766,8 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
> result = DRIVER_ERROR;
> break;
> }
> - scsiback_do_resp_with_sense(NULL, result << 24, 0,
> - pending_req);
> - kmem_cache_free(scsiback_cachep, pending_req);
> + scsiback_do_resp_with_sense(NULL, result << 24, 0, NULL,
> + ring_req.rqid);
> return 1;
> }
>
> @@ -750,8 +776,9 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
> if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
> scsiback_fast_flush_area(pending_req);
> scsiback_do_resp_with_sense(NULL,
> - DRIVER_ERROR << 24, 0, pending_req);
> - kmem_cache_free(scsiback_cachep, pending_req);
> + DRIVER_ERROR << 24, 0,
> pending_req,
> + pending_req->rqid);
> +
> transport_generic_free_cmd(&pending_req->se_cmd, 0);
> } else {
> scsiback_cmd_exec(pending_req);
> }
> @@ -765,9 +792,9 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
> break;
> default:
> pr_err_ratelimited("invalid request\n");
> - scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24,
> - 0, pending_req);
> - kmem_cache_free(scsiback_cachep, pending_req);
> + scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24, 0,
> + pending_req,
> pending_req->rqid);
> + transport_generic_free_cmd(&pending_req->se_cmd, 0);
> break;
> }
>
> @@ -1355,10 +1382,10 @@ static int scsiback_check_stop_free(struct se_cmd
> *se_cmd)
>
> static void scsiback_release_cmd(struct se_cmd *se_cmd)
> {
> - struct vscsibk_pend *pending_req = container_of(se_cmd,
> - struct vscsibk_pend, se_cmd);
> + struct se_session *se_sess = se_cmd->se_sess;
> + struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
>
> - kmem_cache_free(scsiback_cachep, pending_req);
> + percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
> }
>
> static int scsiback_shutdown_session(struct se_session *se_sess)
> @@ -1501,7 +1528,8 @@ static int scsiback_make_nexus(struct scsiback_tpg *tpg,
> goto out_unlock;
> }
>
> - tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg, 0, 0,
> + tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg, 128,
> + sizeof(struct
> vscsibk_pend),
> TARGET_PROT_NORMAL, name,
> tv_nexus, NULL);
> if (IS_ERR(tv_nexus->tvn_se_sess)) {
> @@ -1831,16 +1859,6 @@ static struct xenbus_driver scsiback_driver = {
> .otherend_changed = scsiback_frontend_changed
> };
>
> -static void scsiback_init_pend(void *p)
> -{
> - struct vscsibk_pend *pend = p;
> - int i;
> -
> - memset(pend, 0, sizeof(*pend));
> - for (i = 0; i < VSCSI_MAX_GRANTS; i++)
> - pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
> -}
> -
> static int __init scsiback_init(void)
> {
> int ret;
> @@ -1851,14 +1869,9 @@ static int __init scsiback_init(void)
> pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
> VSCSI_VERSION, utsname()->sysname, utsname()->machine);
>
> - scsiback_cachep = kmem_cache_create("vscsiif_cache",
> - sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
> - if (!scsiback_cachep)
> - return -ENOMEM;
> -
> ret = xenbus_register_backend(&scsiback_driver);
> if (ret)
> - goto out_cache_destroy;
> + goto out;
>
> ret = target_register_template(&scsiback_ops);
> if (ret)
> @@ -1868,8 +1881,7 @@ static int __init scsiback_init(void)
>
> out_unregister_xenbus:
> xenbus_unregister_driver(&scsiback_driver);
> -out_cache_destroy:
> - kmem_cache_destroy(scsiback_cachep);
> +out:
> pr_err("%s: error %d\n", __func__, ret);
> return ret;
> }
> @@ -1885,7 +1897,6 @@ static void __exit scsiback_exit(void)
> }
> target_unregister_template(&scsiback_ops);
> xenbus_unregister_driver(&scsiback_driver);
> - kmem_cache_destroy(scsiback_cachep);
> }
>
> module_init(scsiback_init);
>
--
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