From 6dbe553285c3b55cf4110b5188e8efa11852b2f0 Mon Sep 17 00:00:00 2001 From: Daniel Wagner Date: Wed, 7 May 2025 14:23:05 +0200 Subject: [PATCH] nvmet-fcloop: allocate/free fcloop_lsreq directly fcloop depends on the host or the target to allocate the fcloop_lsreq object. This means that the lifetime of the fcloop_lsreq is tied to either the host or the target. Consequently, the host or the target must cooperate during shutdown. Unfortunately, this approach does not work well when the target forces a shutdown, as there are dependencies that are difficult to resolve in a clean way. The simplest solution is to decouple the lifetime of the fcloop_lsreq object by managing them directly within fcloop. Since this is not a performance-critical path and only a small number of LS objects are used during setup and cleanup, it does not significantly impact performance to allocate them during normal operation. Reviewed-by: Hannes Reinecke Signed-off-by: Daniel Wagner Signed-off-by: Christoph Hellwig --- drivers/nvme/target/fcloop.c | 63 +++++++++++++++++++++++++----------- 1 file changed, 45 insertions(+), 18 deletions(-) diff --git a/drivers/nvme/target/fcloop.c b/drivers/nvme/target/fcloop.c index 52f0061920a8..b952672f38cb 100644 --- a/drivers/nvme/target/fcloop.c +++ b/drivers/nvme/target/fcloop.c @@ -293,6 +293,9 @@ struct fcloop_ini_fcpreq { spinlock_t inilock; }; +/* SLAB cache for fcloop_lsreq structures */ +static struct kmem_cache *lsreq_cache; + static inline struct fcloop_lsreq * ls_rsp_to_lsreq(struct nvmefc_ls_rsp *lsrsp) { @@ -343,6 +346,7 @@ fcloop_rport_lsrqst_work(struct work_struct *work) * callee may free memory containing tls_req. * do not reference lsreq after this. */ + kmem_cache_free(lsreq_cache, tls_req); spin_lock(&rport->lock); } @@ -354,10 +358,13 @@ fcloop_h2t_ls_req(struct nvme_fc_local_port *localport, struct nvme_fc_remote_port *remoteport, struct nvmefc_ls_req *lsreq) { - struct fcloop_lsreq *tls_req = lsreq->private; struct fcloop_rport *rport = remoteport->private; + struct fcloop_lsreq *tls_req; int ret = 0; + tls_req = kmem_cache_alloc(lsreq_cache, GFP_KERNEL); + if (!tls_req) + return -ENOMEM; tls_req->lsreq = lsreq; INIT_LIST_HEAD(&tls_req->ls_list); @@ -394,14 +401,17 @@ fcloop_h2t_xmt_ls_rsp(struct nvmet_fc_target_port *targetport, lsrsp->done(lsrsp); - if (remoteport) { - rport = remoteport->private; - spin_lock(&rport->lock); - list_add_tail(&tls_req->ls_list, &rport->ls_list); - spin_unlock(&rport->lock); - queue_work(nvmet_wq, &rport->ls_work); + if (!remoteport) { + kmem_cache_free(lsreq_cache, tls_req); + return 0; } + rport = remoteport->private; + spin_lock(&rport->lock); + list_add_tail(&tls_req->ls_list, &rport->ls_list); + spin_unlock(&rport->lock); + queue_work(nvmet_wq, &rport->ls_work); + return 0; } @@ -427,6 +437,7 @@ fcloop_tport_lsrqst_work(struct work_struct *work) * callee may free memory containing tls_req. * do not reference lsreq after this. */ + kmem_cache_free(lsreq_cache, tls_req); spin_lock(&tport->lock); } @@ -437,8 +448,8 @@ static int fcloop_t2h_ls_req(struct nvmet_fc_target_port *targetport, void *hosthandle, struct nvmefc_ls_req *lsreq) { - struct fcloop_lsreq *tls_req = lsreq->private; struct fcloop_tport *tport = targetport->private; + struct fcloop_lsreq *tls_req; int ret = 0; /* @@ -446,6 +457,10 @@ fcloop_t2h_ls_req(struct nvmet_fc_target_port *targetport, void *hosthandle, * hosthandle ignored as fcloop currently is * 1:1 tgtport vs remoteport */ + + tls_req = kmem_cache_alloc(lsreq_cache, GFP_KERNEL); + if (!tls_req) + return -ENOMEM; tls_req->lsreq = lsreq; INIT_LIST_HEAD(&tls_req->ls_list); @@ -462,6 +477,9 @@ fcloop_t2h_ls_req(struct nvmet_fc_target_port *targetport, void *hosthandle, ret = nvme_fc_rcv_ls_req(tport->remoteport, &tls_req->ls_rsp, lsreq->rqstaddr, lsreq->rqstlen); + if (ret) + kmem_cache_free(lsreq_cache, tls_req); + return ret; } @@ -481,14 +499,17 @@ fcloop_t2h_xmt_ls_rsp(struct nvme_fc_local_port *localport, lsreq->rsplen : lsrsp->rsplen)); lsrsp->done(lsrsp); - if (targetport) { - tport = targetport->private; - spin_lock(&tport->lock); - list_add_tail(&tls_req->ls_list, &tport->ls_list); - spin_unlock(&tport->lock); - queue_work(nvmet_wq, &tport->ls_work); + if (!targetport) { + kmem_cache_free(lsreq_cache, tls_req); + return 0; } + tport = targetport->private; + spin_lock(&tport->lock); + list_add_tail(&tls_req->ls_list, &tport->ls_list); + spin_unlock(&tport->lock); + queue_work(nvmet_wq, &tport->ls_work); + return 0; } @@ -1121,7 +1142,6 @@ static struct nvme_fc_port_template fctemplate = { /* sizes of additional private data for data structures */ .local_priv_sz = sizeof(struct fcloop_lport_priv), .remote_priv_sz = sizeof(struct fcloop_rport), - .lsrqst_priv_sz = sizeof(struct fcloop_lsreq), .fcprqst_priv_sz = sizeof(struct fcloop_ini_fcpreq), }; @@ -1144,7 +1164,6 @@ static struct nvmet_fc_target_template tgttemplate = { .target_features = 0, /* sizes of additional private data for data structures */ .target_priv_sz = sizeof(struct fcloop_tport), - .lsrqst_priv_sz = sizeof(struct fcloop_lsreq), }; static ssize_t @@ -1664,15 +1683,20 @@ static const struct class fcloop_class = { }; static struct device *fcloop_device; - static int __init fcloop_init(void) { int ret; + lsreq_cache = kmem_cache_create("lsreq_cache", + sizeof(struct fcloop_lsreq), 0, + 0, NULL); + if (!lsreq_cache) + return -ENOMEM; + ret = class_register(&fcloop_class); if (ret) { pr_err("couldn't register class fcloop\n"); - return ret; + goto out_destroy_cache; } fcloop_device = device_create_with_groups( @@ -1690,6 +1714,8 @@ static int __init fcloop_init(void) out_destroy_class: class_unregister(&fcloop_class); +out_destroy_cache: + kmem_cache_destroy(lsreq_cache); return ret; } @@ -1757,6 +1783,7 @@ static void __exit fcloop_exit(void) device_destroy(&fcloop_class, MKDEV(0, 0)); class_unregister(&fcloop_class); + kmem_cache_destroy(lsreq_cache); } module_init(fcloop_init); -- 2.50.1