From: Bart Van Assche <bvanassche@acm.org>
To: "Martin K . Petersen" <martin.petersen@oracle.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
linux-scsi@vger.kernel.org, Bart Van Assche <bvanassche@acm.org>,
"James E.J. Bottomley" <jejb@linux.ibm.com>,
Bean Huo <beanhuo@micron.com>, Can Guo <cang@codeaurora.org>,
Avri Altman <avri.altman@wdc.com>,
Stanley Chu <stanley.chu@mediatek.com>,
Asutosh Das <asutoshd@codeaurora.org>
Subject: [PATCH v2 13/20] scsi: ufs: Fix a deadlock in the error handler
Date: Fri, 19 Nov 2021 11:57:36 -0800 [thread overview]
Message-ID: <20211119195743.2817-14-bvanassche@acm.org> (raw)
In-Reply-To: <20211119195743.2817-1-bvanassche@acm.org>
The following deadlock has been observed on a test setup:
* All tags allocated.
* The SCSI error handler calls ufshcd_eh_host_reset_handler()
* ufshcd_eh_host_reset_handler() queues work that calls ufshcd_err_handler()
* ufshcd_err_handler() locks up as follows:
Workqueue: ufs_eh_wq_0 ufshcd_err_handler.cfi_jt
Call trace:
__switch_to+0x298/0x5d8
__schedule+0x6cc/0xa94
schedule+0x12c/0x298
blk_mq_get_tag+0x210/0x480
__blk_mq_alloc_request+0x1c8/0x284
blk_get_request+0x74/0x134
ufshcd_exec_dev_cmd+0x68/0x640
ufshcd_verify_dev_init+0x68/0x35c
ufshcd_probe_hba+0x12c/0x1cb8
ufshcd_host_reset_and_restore+0x88/0x254
ufshcd_reset_and_restore+0xd0/0x354
ufshcd_err_handler+0x408/0xc58
process_one_work+0x24c/0x66c
worker_thread+0x3e8/0xa4c
kthread+0x150/0x1b4
ret_from_fork+0x10/0x30
Fix this lockup by making ufshcd_exec_dev_cmd() allocate a reserved
request.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/scsi/ufs/ufshcd.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a241ef6bbc6f..03f4772fc2e2 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -128,8 +128,9 @@ EXPORT_SYMBOL_GPL(ufshcd_dump_regs);
enum {
UFSHCD_MAX_CHANNEL = 0,
UFSHCD_MAX_ID = 1,
- UFSHCD_CMD_PER_LUN = 32,
- UFSHCD_CAN_QUEUE = 32,
+ UFSHCD_NUM_RESERVED = 1,
+ UFSHCD_CMD_PER_LUN = 32 - UFSHCD_NUM_RESERVED,
+ UFSHCD_CAN_QUEUE = 32 - UFSHCD_NUM_RESERVED,
};
static const char *const ufshcd_state_name[] = {
@@ -2941,12 +2942,7 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
down_read(&hba->clk_scaling_lock);
- /*
- * Get free slot, sleep if slots are unavailable.
- * Even though we use wait_event() which sleeps indefinitely,
- * the maximum wait time is bounded by SCSI request timeout.
- */
- scmd = scsi_get_internal_cmd(q, DMA_TO_DEVICE, 0);
+ scmd = scsi_get_internal_cmd(q, DMA_TO_DEVICE, BLK_MQ_REQ_RESERVED);
if (IS_ERR(scmd)) {
err = PTR_ERR(scmd);
goto out_unlock;
@@ -8171,6 +8167,7 @@ static struct scsi_host_template ufshcd_driver_template = {
.sg_tablesize = SG_ALL,
.cmd_per_lun = UFSHCD_CMD_PER_LUN,
.can_queue = UFSHCD_CAN_QUEUE,
+ .reserved_tags = UFSHCD_NUM_RESERVED,
.max_segment_size = PRDT_DATA_BYTE_COUNT_MAX,
.max_host_blocked = 1,
.track_queue_depth = 1,
@@ -9531,8 +9528,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
/* Configure LRB */
ufshcd_host_memory_configure(hba);
- host->can_queue = hba->nutrs;
- host->cmd_per_lun = hba->nutrs;
+ host->can_queue = hba->nutrs - UFSHCD_NUM_RESERVED;
+ host->cmd_per_lun = hba->nutrs - UFSHCD_NUM_RESERVED;
host->max_id = UFSHCD_MAX_ID;
host->max_lun = UFS_MAX_LUNS;
host->max_channel = UFSHCD_MAX_CHANNEL;
next prev parent reply other threads:[~2021-11-19 19:58 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-19 19:57 [PATCH v2 00/20] UFS patches for kernel v5.17 Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 01/20] block: Add a flag for internal commands Bart Van Assche
2021-11-22 8:46 ` John Garry
2021-11-22 17:38 ` Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 02/20] scsi: core: Unexport scsi_track_queue_full() Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 03/20] scsi: core: Fix scsi_device_max_queue_depth() Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 04/20] scsi: core: Fix a race between scsi_done() and scsi_times_out() Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 05/20] scsi: core: Add support for internal commands Bart Van Assche
2021-11-22 8:58 ` John Garry
2021-11-22 17:46 ` Bart Van Assche
2021-11-22 18:08 ` John Garry
2021-11-22 19:04 ` Bart Van Assche
2021-11-23 8:13 ` Hannes Reinecke
2021-11-23 17:46 ` Bart Van Assche
2021-11-23 19:18 ` Bart Van Assche
2021-11-24 6:33 ` Hannes Reinecke
2021-11-19 19:57 ` [PATCH v2 06/20] scsi: core: Add support for reserved tags Bart Van Assche
2021-11-22 8:15 ` John Garry
2021-11-22 17:25 ` Bart Van Assche
2021-11-22 18:13 ` John Garry
2021-11-19 19:57 ` [PATCH v2 07/20] scsi: ufs: Rename a function argument Bart Van Assche
2021-11-22 20:25 ` Bean Huo
2021-11-19 19:57 ` [PATCH v2 08/20] scsi: ufs: Remove is_rpmb_wlun() Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 09/20] scsi: ufs: Remove the sdev_rpmb member Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 10/20] scsi: ufs: Remove dead code Bart Van Assche
2021-11-24 11:11 ` Adrian Hunter
2021-11-29 19:12 ` Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 11/20] scsi: ufs: Switch to scsi_(get|put)_internal_cmd() Bart Van Assche
2021-11-23 12:20 ` Bean Huo
2021-11-23 17:54 ` Bart Van Assche
2021-11-23 19:41 ` Bart Van Assche
2021-11-24 18:18 ` Bean Huo
2021-11-24 11:02 ` Adrian Hunter
2021-11-24 11:15 ` Adrian Hunter
2021-11-29 19:32 ` Bart Van Assche
2021-11-30 6:41 ` Adrian Hunter
2021-11-30 17:51 ` Bart Van Assche
2021-11-30 19:15 ` Adrian Hunter
2021-11-30 19:21 ` Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 12/20] scsi: ufs: Rework ufshcd_change_queue_depth() Bart Van Assche
2021-11-19 19:57 ` Bart Van Assche [this message]
2021-11-30 8:54 ` [PATCH v2 13/20] scsi: ufs: Fix a deadlock in the error handler Bean Huo
2021-11-30 17:52 ` Bart Van Assche
2021-11-30 19:32 ` Bart Van Assche
2021-12-01 13:44 ` Bean Huo
2021-12-01 18:31 ` Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 14/20] scsi: ufs: Introduce ufshcd_release_scsi_cmd() Bart Van Assche
2021-11-24 12:03 ` Adrian Hunter
2021-11-30 18:00 ` Bart Van Assche
2021-11-30 19:02 ` Adrian Hunter
2021-11-30 19:16 ` Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 15/20] scsi: ufs: Improve SCSI abort handling Bart Van Assche
2021-11-24 12:28 ` Adrian Hunter
2021-11-30 4:13 ` Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 16/20] scsi: ufs: Fix a kernel crash during shutdown Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 17/20] scsi: ufs: Stop using the clock scaling lock in the error handler Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 18/20] scsi: ufs: Optimize the command queueing code Bart Van Assche
2021-11-22 17:46 ` Asutosh Das (asd)
2021-11-22 18:13 ` Bart Van Assche
2021-11-22 23:02 ` Asutosh Das (asd)
2021-11-22 23:48 ` Bart Van Assche
2021-11-23 18:24 ` Asutosh Das (asd)
2021-12-01 18:33 ` Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 19/20] scsi: ufs: Implement polling support Bart Van Assche
2021-11-30 8:43 ` Bean Huo
2021-11-30 8:57 ` Avri Altman
2021-11-30 9:15 ` Bean Huo
2021-11-30 14:26 ` Bart Van Assche
2021-11-30 15:40 ` Bean Huo
2021-11-30 17:34 ` Bart Van Assche
2021-11-30 17:37 ` Bart Van Assche
2021-11-19 19:57 ` [PATCH v2 20/20] scsi: ufs: Fix race conditions related to driver data Bart Van Assche
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