From 8abda4d28a55ecb91e39ceb5e3ee264c5a3cd1af Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 10 Jan 2012 15:14:09 -0800 Subject: [PATCH] [SCSI] libsas: close scsi_remove_target() vs libata-eh race ata_port lifetime in libata follows the host. In libsas it follows the scsi_target. Once scsi_remove_device() has caused all commands to be completed it allows scsi_remove_target() to immediately proceed to freeing the ata_port causing bug reports like: [ 848.393333] BUG: spinlock bad magic on CPU#4, kworker/u:2/5107 [ 848.400262] general protection fault: 0000 [#1] SMP [ 848.406244] CPU 4 [ 848.408310] Modules linked in: nls_utf8 ipv6 uinput i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support ioatdma dca sg sd_mod sr_mod cdrom ahci libahci isci libsas libata scsi_transport_sas [last unloaded: scsi_wait_scan] [ 848.432060] [ 848.434137] Pid: 5107, comm: kworker/u:2 Not tainted 3.2.0-isci+ #8 Intel Corporation S2600CP/S2600CP [ 848.445310] RIP: 0010:[] [] spin_dump+0x5e/0x8c [ 848.454787] RSP: 0018:ffff8807f868dca0 EFLAGS: 00010002 [ 848.461137] RAX: 0000000000000048 RBX: ffff8807fe86a630 RCX: ffffffff817d0be0 [ 848.469520] RDX: 0000000000000000 RSI: ffffffff814af1cf RDI: 0000000000000002 [ 848.477959] RBP: ffff8807f868dcb0 R08: 00000000ffffffff R09: 000000006b6b6b6b [ 848.486327] R10: 000000000003fb8c R11: ffffffff81a19448 R12: 6b6b6b6b6b6b6b6b [ 848.494699] R13: ffff8808027dc520 R14: 0000000000000000 R15: 000000000000001e [ 848.503067] FS: 0000000000000000(0000) GS:ffff88083fd00000(0000) knlGS:0000000000000000 [ 848.512899] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 848.519710] CR2: 00007ff77d001000 CR3: 00000007f7a5d000 CR4: 00000000000406e0 [ 848.528072] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 848.536446] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 848.544831] Process kworker/u:2 (pid: 5107, threadinfo ffff8807f868c000, task ffff8807ff348000) [ 848.555327] Stack: [ 848.557959] ffff8807fe86a630 ffff8807fe86a630 ffff8807f868dcd0 ffffffff8126a6e0 [ 848.567072] ffffffff817c142f ffff8807fe86a630 ffff8807f868dcf0 ffffffff8126a703 [ 848.576190] ffff8808027dc520 0000000000000286 ffff8807f868dd10 ffffffff814af1bb [ 848.585281] Call Trace: [ 848.588409] [] spin_bug+0x26/0x28 [ 848.594357] [] do_raw_spin_unlock+0x21/0x88 [ 848.601283] [] _raw_spin_unlock_irqrestore+0x2c/0x65 [ 848.609089] [] ata_scsi_port_error_handler+0x548/0x557 [libata] [ 848.618331] [] ? async_schedule+0x17/0x17 [ 848.625060] [] async_sas_ata_eh+0x45/0x69 [libsas] [ 848.632655] [] async_run_entry_fn+0x97/0x125 [ 848.639670] [] process_one_work+0x207/0x38d [ 848.646577] [] ? process_one_work+0x15a/0x38d [ 848.653681] [] worker_thread+0x138/0x21c [ 848.660305] [] ? process_one_work+0x38d/0x38d [ 848.667493] [] kthread+0x9d/0xa5 [ 848.673382] [] ? trace_hardirqs_on_caller+0x12f/0x166 [ 848.681304] [] kernel_thread_helper+0x4/0x10 [ 848.688324] [] ? retint_restore_args+0x13/0x13 [ 848.695530] [] ? __init_kthread_worker+0x5b/0x5b [ 848.702929] [] ? gs_change+0x13/0x13 [ 848.709155] Code: 00 00 48 8d 88 38 04 00 00 44 8b 80 84 02 00 00 31 c0 e8 cf 1b 24 00 41 83 c8 ff 44 8b 4b 08 48 c7 c1 e0 0b 7d 81 4d 85 e4 74 10 <45> 8b 84 24 84 02 00 00 49 8d 8c 24 38 04 00 00 8b 53 04 48 89 [ 848.732467] RIP [] spin_dump+0x5e/0x8c [ 848.738905] RSP [ 848.743743] ---[ end trace 143161646eee8caa ]--- ...so arrange for the ata_port to have the same end of life as the domain device. Reported-by: Marcin Tomczak Acked-by: Jeff Garzik Signed-off-by: Dan Williams Signed-off-by: James Bottomley --- drivers/scsi/libsas/sas_ata.c | 5 +++++ drivers/scsi/libsas/sas_discover.c | 5 +++++ drivers/scsi/libsas/sas_scsi_host.c | 3 --- 3 files changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c index 37a9e73870d4..26a943eb153a 100644 --- a/drivers/scsi/libsas/sas_ata.c +++ b/drivers/scsi/libsas/sas_ata.c @@ -661,8 +661,13 @@ static void async_sas_ata_eh(void *data, async_cookie_t cookie) struct ata_port *ap = dev->sata_dev.ap; struct sas_ha_struct *ha = dev->port->ha; + /* hold a reference over eh since we may be racing with final + * remove once all commands are completed + */ + kref_get(&dev->kref); ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata port error handler"); ata_scsi_port_error_handler(ha->core.shost, ap); + sas_put_device(dev); } void sas_ata_strategy_handler(struct Scsi_Host *shost) diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c index b91866a8233b..4be5ddad7be7 100644 --- a/drivers/scsi/libsas/sas_discover.c +++ b/drivers/scsi/libsas/sas_discover.c @@ -242,6 +242,11 @@ void sas_free_device(struct kref *kref) if (dev->dev_type == EDGE_DEV || dev->dev_type == FANOUT_DEV) kfree(dev->ex_dev.ex_phy); + if (dev_is_sata(dev) && dev->sata_dev.ap) { + ata_sas_port_destroy(dev->sata_dev.ap); + dev->sata_dev.ap = NULL; + } + kfree(dev); } diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c index 731c89250639..b563ff27626b 100644 --- a/drivers/scsi/libsas/sas_scsi_host.c +++ b/drivers/scsi/libsas/sas_scsi_host.c @@ -1028,9 +1028,6 @@ void sas_target_destroy(struct scsi_target *starget) if (!found_dev) return; - if (dev_is_sata(found_dev)) - ata_sas_port_destroy(found_dev->sata_dev.ap); - starget->hostdata = NULL; sas_put_device(found_dev); }