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:[<ffffffff8126a68c>] [<ffffffff8126a68c>] 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] [<ffffffff8126a6e0>] spin_bug+0x26/0x28
[ 848.594357] [<ffffffff8126a703>] do_raw_spin_unlock+0x21/0x88
[ 848.601283] [<ffffffff814af1bb>] _raw_spin_unlock_irqrestore+0x2c/0x65
[ 848.609089] [<ffffffffa001c103>] ata_scsi_port_error_handler+0x548/0x557 [libata]
[ 848.618331] [<ffffffff81061813>] ? async_schedule+0x17/0x17
[ 848.625060] [<ffffffffa004f30f>] async_sas_ata_eh+0x45/0x69 [libsas]
[ 848.632655] [<ffffffff810618aa>] async_run_entry_fn+0x97/0x125
[ 848.639670] [<ffffffff81057439>] process_one_work+0x207/0x38d
[ 848.646577] [<ffffffff8105738c>] ? process_one_work+0x15a/0x38d
[ 848.653681] [<ffffffff810576f7>] worker_thread+0x138/0x21c
[ 848.660305] [<ffffffff810575bf>] ? process_one_work+0x38d/0x38d
[ 848.667493] [<ffffffff8105b098>] kthread+0x9d/0xa5
[ 848.673382] [<ffffffff8106e1bd>] ? trace_hardirqs_on_caller+0x12f/0x166
[ 848.681304] [<ffffffff814b7704>] kernel_thread_helper+0x4/0x10
[ 848.688324] [<ffffffff814af534>] ? retint_restore_args+0x13/0x13
[ 848.695530] [<ffffffff8105affb>] ? __init_kthread_worker+0x5b/0x5b
[ 848.702929] [<ffffffff814b7700>] ? 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 [<ffffffff8126a68c>] spin_dump+0x5e/0x8c
[ 848.738905] RSP <ffff8807f868dca0>
[ 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 <marcin.tomczak@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
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 a062adc..2c00a38 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);
/* tell scsi_block_when_processing_errors() waiters that we are
* still making forward progress
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 3ef7741..9367101 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 731c892..b563ff2 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);
}
--
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