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| author | Vaibhav Jain <vaibhav@linux.ibm.com> | 2019-01-30 17:56:51 +0530 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2019-02-04 22:24:02 -0500 |
| commit | bb61b843ffd46978d7ca5095453e572714934eeb (patch) | |
| tree | 50cc499df3d10e6c5653fda71049f643c1c30469 /drivers/scsi/cxlflash/main.c | |
| parent | d8f6382a7d026989029e2e50c515df954488459b (diff) | |
| download | lwn-bb61b843ffd46978d7ca5095453e572714934eeb.tar.gz lwn-bb61b843ffd46978d7ca5095453e572714934eeb.zip | |
scsi: cxlflash: Prevent deadlock when adapter probe fails
Presently when an error is encountered during probe of the cxlflash
adapter, a deadlock is seen with cpu thread stuck inside
cxlflash_remove(). Below is the trace of the deadlock as logged by
khungtaskd:
cxlflash 0006:00:00.0: cxlflash_probe: init_afu failed rc=-16
INFO: task kworker/80:1:890 blocked for more than 120 seconds.
Not tainted 5.0.0-rc4-capi2-kexec+ #2
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/80:1 D 0 890 2 0x00000808
Workqueue: events work_for_cpu_fn
Call Trace:
0x4d72136320 (unreliable)
__switch_to+0x2cc/0x460
__schedule+0x2bc/0xac0
schedule+0x40/0xb0
cxlflash_remove+0xec/0x640 [cxlflash]
cxlflash_probe+0x370/0x8f0 [cxlflash]
local_pci_probe+0x6c/0x140
work_for_cpu_fn+0x38/0x60
process_one_work+0x260/0x530
worker_thread+0x280/0x5d0
kthread+0x1a8/0x1b0
ret_from_kernel_thread+0x5c/0x80
INFO: task systemd-udevd:5160 blocked for more than 120 seconds.
The deadlock occurs as cxlflash_remove() is called from cxlflash_probe()
without setting 'cxlflash_cfg->state' to STATE_PROBED and the probe thread
starts to wait on 'cxlflash_cfg->reset_waitq'. Since the device was never
successfully probed the 'cxlflash_cfg->state' never changes from
STATE_PROBING hence the deadlock occurs.
We fix this deadlock by setting the variable 'cxlflash_cfg->state' to
STATE_PROBED in case an error occurs during cxlflash_probe() and just
before calling cxlflash_remove().
Cc: stable@vger.kernel.org
Fixes: c21e0bbfc485("cxlflash: Base support for IBM CXL Flash Adapter")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/cxlflash/main.c')
| -rw-r--r-- | drivers/scsi/cxlflash/main.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index bfa13e3b191c..c8bad2c093b8 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -3687,6 +3687,7 @@ static int cxlflash_probe(struct pci_dev *pdev, host->max_cmd_len = CXLFLASH_MAX_CDB_LEN; cfg = shost_priv(host); + cfg->state = STATE_PROBING; cfg->host = host; rc = alloc_mem(cfg); if (rc) { @@ -3775,6 +3776,7 @@ out: return rc; out_remove: + cfg->state = STATE_PROBED; cxlflash_remove(pdev); goto out; } |