[GIT PULL] SCSI fixes for 5.19-rc8

[James Bottomley]

Four fixes, three in drivers.  The two biggest fixes are ufs and the
remaining driver and core fix are small and obvious (and the core fix
is low risk).

The patch is available here:

git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes

The short changelog is:

Bart Van Assche (1):
      scsi: ufs: core: Fix a race condition related to device management

David Jeffery (1):
      scsi: mpt3sas: Stop fw fault watchdog work item during system shutdown

Jason Yan (1):
      scsi: core: Fix warning in scsi_alloc_sgtables()

Liang He (1):
      scsi: ufs: host: Hold reference returned by of_parse_phandle()

And the diffstat:

 drivers/scsi/mpt3sas/mpt3sas_scsih.c |  1 +
 drivers/scsi/scsi_ioctl.c            |  2 +-
 drivers/ufs/core/ufshcd.c            | 58 +++++++++++++++++++++++++-----------
 drivers/ufs/host/ufshcd-pltfrm.c     | 15 ++++++++--
 4 files changed, 55 insertions(+), 21 deletions(-)

With full diff below.

James

---
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index b519f4b59d30..5e8887fa02c8 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -11386,6 +11386,7 @@ scsih_shutdown(struct pci_dev *pdev)
 	_scsih_ir_shutdown(ioc);
 	_scsih_nvme_shutdown(ioc);
 	mpt3sas_base_mask_interrupts(ioc);
+	mpt3sas_base_stop_watchdog(ioc);
 	ioc->shost_recovery = 1;
 	mpt3sas_base_make_ioc_ready(ioc, SOFT_RESET);
 	ioc->shost_recovery = 0;
diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c
index a480c4d589f5..729e309e6034 100644
--- a/drivers/scsi/scsi_ioctl.c
+++ b/drivers/scsi/scsi_ioctl.c
@@ -450,7 +450,7 @@ static int sg_io(struct scsi_device *sdev, struct sg_io_hdr *hdr, fmode_t mode)
 		goto out_put_request;
 
 	ret = 0;
-	if (hdr->iovec_count) {
+	if (hdr->iovec_count && hdr->dxfer_len) {
 		struct iov_iter i;
 		struct iovec *iov = NULL;
 
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index c7b337480e3e..3d367be71728 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2953,37 +2953,59 @@ ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
 		struct ufshcd_lrb *lrbp, int max_timeout)
 {
-	int err = 0;
-	unsigned long time_left;
+	unsigned long time_left = msecs_to_jiffies(max_timeout);
 	unsigned long flags;
+	bool pending;
+	int err;
 
+retry:
 	time_left = wait_for_completion_timeout(hba->dev_cmd.complete,
-			msecs_to_jiffies(max_timeout));
+						time_left);
 
-	spin_lock_irqsave(hba->host->host_lock, flags);
-	hba->dev_cmd.complete = NULL;
 	if (likely(time_left)) {
+		/*
+		 * The completion handler called complete() and the caller of
+		 * this function still owns the @lrbp tag so the code below does
+		 * not trigger any race conditions.
+		 */
+		hba->dev_cmd.complete = NULL;
 		err = ufshcd_get_tr_ocs(lrbp);
 		if (!err)
 			err = ufshcd_dev_cmd_completion(hba, lrbp);
-	}
-	spin_unlock_irqrestore(hba->host->host_lock, flags);
-
-	if (!time_left) {
+	} else {
 		err = -ETIMEDOUT;
 		dev_dbg(hba->dev, "%s: dev_cmd request timedout, tag %d\n",
 			__func__, lrbp->task_tag);
-		if (!ufshcd_clear_cmds(hba, 1U << lrbp->task_tag))
+		if (ufshcd_clear_cmds(hba, 1U << lrbp->task_tag) == 0) {
 			/* successfully cleared the command, retry if needed */
 			err = -EAGAIN;
-		/*
-		 * in case of an error, after clearing the doorbell,
-		 * we also need to clear the outstanding_request
-		 * field in hba
-		 */
-		spin_lock_irqsave(&hba->outstanding_lock, flags);
-		__clear_bit(lrbp->task_tag, &hba->outstanding_reqs);
-		spin_unlock_irqrestore(&hba->outstanding_lock, flags);
+			/*
+			 * Since clearing the command succeeded we also need to
+			 * clear the task tag bit from the outstanding_reqs
+			 * variable.
+			 */
+			spin_lock_irqsave(&hba->outstanding_lock, flags);
+			pending = test_bit(lrbp->task_tag,
+					   &hba->outstanding_reqs);
+			if (pending) {
+				hba->dev_cmd.complete = NULL;
+				__clear_bit(lrbp->task_tag,
+					    &hba->outstanding_reqs);
+			}
+			spin_unlock_irqrestore(&hba->outstanding_lock, flags);
+
+			if (!pending) {
+				/*
+				 * The completion handler ran while we tried to
+				 * clear the command.
+				 */
+				time_left = 1;
+				goto retry;
+			}
+		} else {
+			dev_err(hba->dev, "%s: failed to clear tag %d\n",
+				__func__, lrbp->task_tag);
+		}
 	}
 
 	return err;
diff --git a/drivers/ufs/host/ufshcd-pltfrm.c b/drivers/ufs/host/ufshcd-pltfrm.c
index e7332cc65b1f..173aea8e9997 100644
--- a/drivers/ufs/host/ufshcd-pltfrm.c
+++ b/drivers/ufs/host/ufshcd-pltfrm.c
@@ -108,9 +108,20 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
 	return ret;
 }
 
+static bool phandle_exists(const struct device_node *np,
+			   const char *phandle_name, int index)
+{
+	struct device_node *parse_np = of_parse_phandle(np, phandle_name, index);
+
+	if (parse_np)
+		of_node_put(parse_np);
+
+	return parse_np != NULL;
+}
+
 #define MAX_PROP_SIZE 32
 static int ufshcd_populate_vreg(struct device *dev, const char *name,
-		struct ufs_vreg **out_vreg)
+				struct ufs_vreg **out_vreg)
 {
 	char prop_name[MAX_PROP_SIZE];
 	struct ufs_vreg *vreg = NULL;
@@ -122,7 +133,7 @@ static int ufshcd_populate_vreg(struct device *dev, const char *name,
 	}
 
 	snprintf(prop_name, MAX_PROP_SIZE, "%s-supply", name);
-	if (!of_parse_phandle(np, prop_name, 0)) {
+	if (!phandle_exists(np, prop_name, 0)) {
 		dev_info(dev, "%s: Unable to find %s regulator, assuming enabled\n",
 				__func__, prop_name);
 		goto out;