From: Glenn Watkins <Glenn.Watkins@xxxxxxxxxxxxxx> Under conditions of offlining drives, and rescanning the scsi host, we can get into situations that the megasas_aen_polling kthread can crash(GPF) in the megasas_aen_polling work queue: [ 1206.568641] general protection fault: 0000 [#1] SMP [ 1206.569479] Modules linked in: xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack iptable_filter ip_tables x_tables coretemp crct10dif_pclmul crc32_pclmul aesni_intel ablk_helper cryptd psmouse lrw vmwgfx gf128mul serio_raw glue_helper aes_x86_64 ppdev ttm microcode vmw_balloon drm_kms_helper drm parport_pc parport fb_sys_fops sysimgblt sysfillrect syscopyarea vmw_vmci binfmt_misc floppy mptspi mptscsih vmw_pvscsi megaraid_sas pata_acpi mptbase vmxnet3 [ 1206.576488] CPU: 0 PID: 1157 Comm: kworker/0:2 Not tainted 4.3.0-rc7-svt1 #1 [ 1206.577520] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/14/2014 [ 1206.579101] Workqueue: events megasas_aen_polling [megaraid_sas] [ 1206.580007] task: ffff8818bb7b8000 ti: ffff8818ca280000 task.ti: ffff8818ca280000 [ 1206.581104] RIP: 0010:[<ffffffff8118403d>] [<ffffffff8118403d>] bdi_unregister+0x3d/0x1e0 [ 1206.582339] RSP: 0018:ffff8818ca283cb8 EFLAGS: 00010246 [ 1206.583131] RAX: dead000000000200 RBX: ffff8818bb603f08 RCX: ffff8818c6487800 [ 1206.584184] RDX: ffff8818bb603f08 RSI: 000000007fffffff RDI: ffffffff81f9aa68 [ 1206.585243] RBP: ffff8818ca283d18 R08: 0000000000000000 R09: 0000000000000000 [ 1206.586294] R10: 0000000fffffffe0 R11: dead000000000200 R12: ffff8818bb6042f0 [ 1206.587346] R13: ffff8818bb604530 R14: 00000000000000ae R15: 0000000000000080 [ 1206.588388] FS: 0000000000000000(0000) GS:ffff88193fc00000(0000) knlGS:0000000000000000 [ 1206.589598] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1206.590457] CR2: 0000000001a89000 CR3: 00000018c07f2000 CR4: 00000000000406f0 [ 1206.591545] Stack: [ 1206.591870] ffff8818bb6042f0 ffff8818bb603d78 00000000000000ae 0000000000000080 [ 1206.593098] ffff8818ca283ce8 ffffffff8108f683 ffff8818ca283d18 ffffffff813332b0 [ 1206.594308] ffff8818ca283d18 ffff8818bb603d78 ffff8818bb6042f0 ffff8818bb604530 [ 1206.595532] Call Trace: [ 1206.595922] [<ffffffff8108f683>] ? cancel_delayed_work_sync+0x13/0x20 [ 1206.596903] [<ffffffff813332b0>] ? blk_sync_queue+0x80/0x90 [ 1206.597753] [<ffffffff81336424>] blk_cleanup_queue+0x114/0x150 [ 1206.598645] [<ffffffff814efe44>] __scsi_remove_device+0x54/0xd0 [ 1206.599556] [<ffffffff814efeef>] scsi_remove_device+0x2f/0x50 [ 1206.600441] [<ffffffffa003884d>] megasas_aen_polling+0x34d/0x670 [megaraid_sas] [ 1206.601561] [<ffffffff8108ddcc>] process_one_work+0x14c/0x400 [ 1206.602449] [<ffffffff8108e6a7>] worker_thread+0x117/0x480 [ 1206.603295] [<ffffffff8108e590>] ? create_worker+0x1c0/0x1c0 [ 1206.604160] [<ffffffff81094bf9>] kthread+0xc9/0xe0 [ 1206.604898] [<ffffffff81094b30>] ? flush_kthread_worker+0x90/0x90 [ 1206.605831] [<ffffffff8171bf8f>] ret_from_fork+0x3f/0x70 [ 1206.606659] [<ffffffff81094b30>] ? flush_kthread_worker+0x90/0x90 [ 1206.607585] Code: c7 c7 68 aa f9 81 48 83 ec 48 e8 bf 76 59 00 48 8b 43 08 48 8b 13 49 bb 00 02 00 00 00 00 ad de 48 c7 c7 68 aa f9 81 48 89 42 08 <48> 89 10 4c 89 5b 08 e8 27 76 59 00 e8 32 92 f4 ff 48 8d 7b 50 [ 1206.611938] RIP [<ffffffff8118403d>] bdi_unregister+0x3d/0x1e0 [ 1206.612856] RSP <ffff8818ca283cb8> This can be readily reproduced by a pair of shell scripts - one of which loops on onlining / offlining drives via MegaCli (or storcli, if you prefer) #!/bin/bash while [ 1 ]; do /opt/MegaRAID/MegaCli/MegaCli64 pdoffline physdrv[32:0] a0 &>2 /opt/MegaRAID/MegaCli/MegaCli64 pdoffline physdrv[32:11] a0 &>2 /opt/MegaRAID/MegaCli/MegaCli64 pdonline physdrv[32:0] a0 &>2 /opt/MegaRAID/MegaCli/MegaCli64 pdonline physdrv[32:11] a0 &>2 done Meanwhile, the second script is looping on rescanning the scsi hosts: #!/bin/bash while [ 1 ]; do for (( l=0; l<4; l++ )); do echo - - - > /sys/class/scsi_host/host$l/scan done done This was originally introduced in the following commit: commit 7e8a75f4dfbff173977b2f58799c3eceb7b09afd Author: Yang, Bo <Bo.Yang@xxxxxxx> Date: Tue Oct 6 14:50:17 2009 -0600 [SCSI] megaraid_sas: Add the support for updating the OS after adding/removing the devices from FW The fix for this is to add some locking around the AEN polling. Since this affects all kernels since 2.6.33, I have also CC'ed the stable list. Signed-off-by: Glenn Watkins <Glenn.Watkins@xxxxxxxxxxxxxx> Signed-off-by: Ben Guthro <ben.guthro@xxxxxxxxxxxxxx> --- drivers/scsi/megaraid/megaraid_sas_base.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index eaa81e5..d203d9d 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -6640,6 +6640,7 @@ megasas_aen_polling(struct work_struct *work) if (doscan) { dev_info(&instance->pdev->dev, "scanning for scsi%d...\n", instance->host->host_no); + mutex_lock(&host->scan_mutex); if (megasas_get_pd_list(instance) == 0) { for (i = 0; i < MEGASAS_MAX_PD_CHANNELS; i++) { for (j = 0; j < MEGASAS_MAX_DEV_PER_CHANNEL; j++) { @@ -6661,6 +6662,7 @@ megasas_aen_polling(struct work_struct *work) } } } + mutex_unlock(&host->scan_mutex); if (!instance->requestorId || (instance->requestorId && -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html