Currently, the sub-queues and event pool resources are alloc/free'd for every CRQ connection event such as reset and LPM. This exposes the driver to a couple issues. First the inefficiency of freeing and reallocating memory that can simply be resued after being sanitized. Further, a system under memory pressue runs the risk of allocation failures that could result in a cripled driver. Finally, there is a race window where command submission/compeletion can try to pull/return elements from/to an event pool that is being deleted or already has been deleted due to the lack of host state around freeing/allocating resources. The following is an example of list corruption following a live partition migration (LPM):
Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: vfat fat isofs cdrom ext4 mbcache jbd2 nft_counter nft_compat nf_tables nfnetlink rpadlpar_io rpaphp xsk_diag nfsv3 nfs_acl nfs lockd grace fscache netfs rfkill bonding tls sunrpc pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c dm_service_time sd_mod t10_pi sg ibmvfc scsi_transport_fc ibmveth vmx_crypto dm_multipath dm_mirror dm_region_hash dm_log dm_mod ipmi_devintf ipmi_msghandler fuse CPU: 0 PID: 2108 Comm: ibmvfc_0 Kdump: loaded Not tainted 5.14.0-70.9.1.el9_0.ppc64le #1 NIP: c0000000007c4bb0 LR: c0000000007c4bac CTR: 00000000005b9a10 REGS: c00000025c10b760 TRAP: 0700 Not tainted (5.14.0-70.9.1.el9_0.ppc64le) MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 2800028f XER: 0000000f CFAR: c0000000001f55bc IRQMASK: 0 GPR00: c0000000007c4bac c00000025c10ba00 c000000002a47c00 000000000000004e GPR04: c0000031e3006f88 c0000031e308bd00 c00000025c10b768 0000000000000027 GPR08: 0000000000000000 c0000031e3009dc0 00000031e0eb0000 0000000000000000 GPR12: c0000031e2ffffa8 c000000002dd0000 c000000000187108 c00000020fcee2c0 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 c008000002f81300 GPR24: 5deadbeef0000100 5deadbeef0000122 c000000263ba6910 c00000024cc88000 GPR28: 000000000000003c c0000002430a0000 c0000002430ac300 000000000000c300 NIP [c0000000007c4bb0] __list_del_entry_valid+0x90/0x100 LR [c0000000007c4bac] __list_del_entry_valid+0x8c/0x100 Call Trace: [c00000025c10ba00] [c0000000007c4bac] __list_del_entry_valid+0x8c/0x100 (unreliable) [c00000025c10ba60] [c008000002f42284] ibmvfc_free_queue+0xec/0x210 [ibmvfc] [c00000025c10bb10] [c008000002f4246c] ibmvfc_deregister_scsi_channel+0xc4/0x160 [ibmvfc] [c00000025c10bba0] [c008000002f42580] ibmvfc_release_sub_crqs+0x78/0x130 [ibmvfc] [c00000025c10bc20] [c008000002f4f6cc] ibmvfc_do_work+0x5c4/0xc70 [ibmvfc] [c00000025c10bce0] [c008000002f4fdec] ibmvfc_work+0x74/0x1e8 [ibmvfc] [c00000025c10bda0] [c0000000001872b8] kthread+0x1b8/0x1c0 [c00000025c10be10] [c00000000000cd64] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 40820034 38600001 38210060 4e800020 7c0802a6 7c641b78 3c62fe7a 7d254b78 3863b590 f8010070 4ba309cd 60000000 <0fe00000> 7c0802a6 3c62fe7a 3863b640 ---[ end trace 11a2b65a92f8b66c ]--- ibmvfc 30000003: Send warning. Receive queue closed, will retry.
Add registration/deregistartion helpers that are called instead during connection resets to sanitize and reconfigure the queues.
Fixes: 3034ebe26389 ("scsi: ibmvfc: Add alloc/dealloc routines for SCSI Sub-CRQ Channels") Cc: stable@vger.kernel.org Signed-off-by: Tyrel Datwyler tyreld@linux.ibm.com Reviewed-by: Brian King brking@linux.vnet.ibm.com --- drivers/scsi/ibmvscsi/ibmvfc.c | 79 ++++++++++++++++++++++++++-------- 1 file changed, 62 insertions(+), 17 deletions(-)
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c index 9fc0ffda6ae8..00684e11976b 100644 --- a/drivers/scsi/ibmvscsi/ibmvfc.c +++ b/drivers/scsi/ibmvscsi/ibmvfc.c @@ -160,8 +160,8 @@ static void ibmvfc_npiv_logout(struct ibmvfc_host *); static void ibmvfc_tgt_implicit_logout_and_del(struct ibmvfc_target *); static void ibmvfc_tgt_move_login(struct ibmvfc_target *);
-static void ibmvfc_release_sub_crqs(struct ibmvfc_host *); -static void ibmvfc_init_sub_crqs(struct ibmvfc_host *); +static void ibmvfc_dereg_sub_crqs(struct ibmvfc_host *); +static void ibmvfc_reg_sub_crqs(struct ibmvfc_host *);
static const char *unknown_error = "unknown error";
@@ -917,7 +917,7 @@ static int ibmvfc_reenable_crq_queue(struct ibmvfc_host *vhost) struct vio_dev *vdev = to_vio_dev(vhost->dev); unsigned long flags;
- ibmvfc_release_sub_crqs(vhost); + ibmvfc_dereg_sub_crqs(vhost);
/* Re-enable the CRQ */ do { @@ -936,7 +936,7 @@ static int ibmvfc_reenable_crq_queue(struct ibmvfc_host *vhost) spin_unlock(vhost->crq.q_lock); spin_unlock_irqrestore(vhost->host->host_lock, flags);
- ibmvfc_init_sub_crqs(vhost); + ibmvfc_reg_sub_crqs(vhost);
return rc; } @@ -955,7 +955,7 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost) struct vio_dev *vdev = to_vio_dev(vhost->dev); struct ibmvfc_queue *crq = &vhost->crq;
- ibmvfc_release_sub_crqs(vhost); + ibmvfc_dereg_sub_crqs(vhost);
/* Close the CRQ */ do { @@ -988,7 +988,7 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost) spin_unlock(vhost->crq.q_lock); spin_unlock_irqrestore(vhost->host->host_lock, flags);
- ibmvfc_init_sub_crqs(vhost); + ibmvfc_reg_sub_crqs(vhost);
return rc; } @@ -5759,9 +5759,6 @@ static int ibmvfc_register_scsi_channel(struct ibmvfc_host *vhost,
ENTER;
- if (ibmvfc_alloc_queue(vhost, scrq, IBMVFC_SUB_CRQ_FMT)) - return -ENOMEM; - rc = h_reg_sub_crq(vdev->unit_address, scrq->msg_token, PAGE_SIZE, &scrq->cookie, &scrq->hw_irq);
@@ -5801,7 +5798,6 @@ static int ibmvfc_register_scsi_channel(struct ibmvfc_host *vhost, rc = plpar_hcall_norets(H_FREE_SUB_CRQ, vdev->unit_address, scrq->cookie); } while (rtas_busy_delay(rc)); reg_failed: - ibmvfc_free_queue(vhost, scrq); LEAVE; return rc; } @@ -5827,12 +5823,50 @@ static void ibmvfc_deregister_scsi_channel(struct ibmvfc_host *vhost, int index) if (rc) dev_err(dev, "Failed to free sub-crq[%d]: rc=%ld\n", index, rc);
- ibmvfc_free_queue(vhost, scrq); + /* Clean out the queue */ + memset(scrq->msgs.crq, 0, PAGE_SIZE); + scrq->cur = 0; + + LEAVE; +} + +static void ibmvfc_reg_sub_crqs(struct ibmvfc_host *vhost) +{ + int i, j; + + ENTER; + if (!vhost->mq_enabled || !vhost->scsi_scrqs.scrqs) + return; + + for (i = 0; i < nr_scsi_hw_queues; i++) { + if (ibmvfc_register_scsi_channel(vhost, i)) { + for (j = i; j > 0; j--) + ibmvfc_deregister_scsi_channel(vhost, j - 1); + vhost->do_enquiry = 0; + return; + } + } + + LEAVE; +} + +static void ibmvfc_dereg_sub_crqs(struct ibmvfc_host *vhost) +{ + int i; + + ENTER; + if (!vhost->mq_enabled || !vhost->scsi_scrqs.scrqs) + return; + + for (i = 0; i < nr_scsi_hw_queues; i++) + ibmvfc_deregister_scsi_channel(vhost, i); + LEAVE; }
static void ibmvfc_init_sub_crqs(struct ibmvfc_host *vhost) { + struct ibmvfc_queue *scrq; int i, j;
ENTER; @@ -5848,30 +5882,41 @@ static void ibmvfc_init_sub_crqs(struct ibmvfc_host *vhost) }
for (i = 0; i < nr_scsi_hw_queues; i++) { - if (ibmvfc_register_scsi_channel(vhost, i)) { - for (j = i; j > 0; j--) - ibmvfc_deregister_scsi_channel(vhost, j - 1); + scrq = &vhost->scsi_scrqs.scrqs[i]; + if (ibmvfc_alloc_queue(vhost, scrq, IBMVFC_SUB_CRQ_FMT)) { + for (j = i; j > 0; j--) { + scrq = &vhost->scsi_scrqs.scrqs[j - 1]; + ibmvfc_free_queue(vhost, scrq); + } kfree(vhost->scsi_scrqs.scrqs); vhost->scsi_scrqs.scrqs = NULL; vhost->scsi_scrqs.active_queues = 0; vhost->do_enquiry = 0; - break; + vhost->mq_enabled = 0; + return; } }
+ ibmvfc_reg_sub_crqs(vhost); + LEAVE; }
static void ibmvfc_release_sub_crqs(struct ibmvfc_host *vhost) { + struct ibmvfc_queue *scrq; int i;
ENTER; if (!vhost->scsi_scrqs.scrqs) return;
- for (i = 0; i < nr_scsi_hw_queues; i++) - ibmvfc_deregister_scsi_channel(vhost, i); + ibmvfc_dereg_sub_crqs(vhost); + + for (i = 0; i < nr_scsi_hw_queues; i++) { + scrq = &vhost->scsi_scrqs.scrqs[i]; + ibmvfc_free_queue(vhost, scrq); + }
kfree(vhost->scsi_scrqs.scrqs); vhost->scsi_scrqs.scrqs = NULL;