[PATCH AUTOSEL 6.2 09/30] cpumask: fix incorrect cpumask scanning result checks

[PATCH AUTOSEL 6.2 09/30] cpumask: fix incorrect cpumask scanning result checks

[Sasha Levin]

From: Linus Torvalds <torvalds@linux-foundation.org>

[ Upstream commit 8ca09d5fa3549d142c2080a72a4c70ce389163cd ]

It turns out that commit 596ff4a09b89 ("cpumask: re-introduce
constant-sized cpumask optimizations") exposed a number of cases of
drivers not checking the result of "cpumask_next()" and friends
correctly.

The documented correct check for "no more cpus in the cpumask" is to
check for the result being equal or larger than the number of possible
CPU ids, exactly _because_ we've always done those constant-sized
cpumask scans using a widened type before.  So the return value of a
cpumask scan should be checked with

	if (cpu >= nr_cpu_ids)
		...

because the cpumask scan did not necessarily stop exactly *at* that
maximum CPU id.

But a few cases ended up instead using checks like

	if (cpu == nr_cpumask_bits)
		...

which used that internal "widened" number of bits.  And that used to
work pretty much by accident (ok, in this case "by accident" is simply
because it matched the historical internal implementation of the cpumask
scanning, so it was more of a "intentionally using implementation
details rather than an accident").

But the extended constant-sized optimizations then did that internal
implementation differently, and now that code that did things wrong but
matched the old implementation no longer worked at all.

Which then causes subsequent odd problems due to using what ends up
being an invalid CPU ID.

Most of these cases require either unusual hardware or special uses to
hit, but the random.c one triggers quite easily.

All you really need is to have a sufficiently small CONFIG_NR_CPUS value
for the bit scanning optimization to be triggered, but not enough CPUs
to then actually fill that widened cpumask.  At that point, the cpumask
scanning will return the NR_CPUS constant, which is _not_ the same as
nr_cpumask_bits.

This just does the mindless fix with

   sed -i 's/== nr_cpumask_bits/>= nr_cpu_ids/'

to fix the incorrect uses.

The ones in the SCSI lpfc driver in particular could probably be fixed
more cleanly by just removing that repeated pattern entirely, but I am
not emptionally invested enough in that driver to care.

Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/lkml/481b19b5-83a0-4793-b4fd-194ad7b978c3@roeck-us.net/
Reported-and-tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/lkml/CAMuHMdUKo_Sf7TjKzcNDa8Ve+6QrK+P8nSQrSQ=6LTRmcBKNww@mail.gmail.com/
Reported-by: Vernon Yang <vernon2gm@gmail.com>
Link: https://lore.kernel.org/lkml/20230306160651.2016767-1-vernon2gm@gmail.com/
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/xmon/xmon.c         |  2 +-
 drivers/char/random.c            |  2 +-
 drivers/net/wireguard/queueing.h |  2 +-
 drivers/scsi/lpfc/lpfc_init.c    | 14 +++++++-------
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 0da66bc4823d4..3b4e2475fc4ef 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1277,7 +1277,7 @@ static int xmon_batch_next_cpu(void)
 	while (!cpumask_empty(&xmon_batch_cpus)) {
 		cpu = cpumask_next_wrap(smp_processor_id(), &xmon_batch_cpus,
 					xmon_batch_start_cpu, true);
-		if (cpu == nr_cpumask_bits)
+		if (cpu >= nr_cpu_ids)
 			break;
 		if (xmon_batch_start_cpu == -1)
 			xmon_batch_start_cpu = cpu;
diff --git a/drivers/char/random.c b/drivers/char/random.c
index ce3ccd172cc86..253f2ddb89130 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1311,7 +1311,7 @@ static void __cold try_to_generate_entropy(void)
 			/* Basic CPU round-robin, which avoids the current CPU. */
 			do {
 				cpu = cpumask_next(cpu, &timer_cpus);
-				if (cpu == nr_cpumask_bits)
+				if (cpu >= nr_cpu_ids)
 					cpu = cpumask_first(&timer_cpus);
 			} while (cpu == smp_processor_id() && num_cpus > 1);
 
diff --git a/drivers/net/wireguard/queueing.h b/drivers/net/wireguard/queueing.h
index 583adb37ee1e3..125284b346a77 100644
--- a/drivers/net/wireguard/queueing.h
+++ b/drivers/net/wireguard/queueing.h
@@ -106,7 +106,7 @@ static inline int wg_cpumask_choose_online(int *stored_cpu, unsigned int id)
 {
 	unsigned int cpu = *stored_cpu, cpu_index, i;
 
-	if (unlikely(cpu == nr_cpumask_bits ||
+	if (unlikely(cpu >= nr_cpu_ids ||
 		     !cpumask_test_cpu(cpu, cpu_online_mask))) {
 		cpu_index = id % cpumask_weight(cpu_online_mask);
 		cpu = cpumask_first(cpu_online_mask);
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 25ba20e428255..3fbd3bec26fc1 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -12507,7 +12507,7 @@ lpfc_cpu_affinity_check(struct lpfc_hba *phba, int vectors)
 					goto found_same;
 				new_cpu = cpumask_next(
 					new_cpu, cpu_present_mask);
-				if (new_cpu == nr_cpumask_bits)
+				if (new_cpu >= nr_cpu_ids)
 					new_cpu = first_cpu;
 			}
 			/* At this point, we leave the CPU as unassigned */
@@ -12521,7 +12521,7 @@ lpfc_cpu_affinity_check(struct lpfc_hba *phba, int vectors)
 			 * selecting the same IRQ.
 			 */
 			start_cpu = cpumask_next(new_cpu, cpu_present_mask);
-			if (start_cpu == nr_cpumask_bits)
+			if (start_cpu >= nr_cpu_ids)
 				start_cpu = first_cpu;
 
 			lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
@@ -12557,7 +12557,7 @@ lpfc_cpu_affinity_check(struct lpfc_hba *phba, int vectors)
 					goto found_any;
 				new_cpu = cpumask_next(
 					new_cpu, cpu_present_mask);
-				if (new_cpu == nr_cpumask_bits)
+				if (new_cpu >= nr_cpu_ids)
 					new_cpu = first_cpu;
 			}
 			/* We should never leave an entry unassigned */
@@ -12575,7 +12575,7 @@ lpfc_cpu_affinity_check(struct lpfc_hba *phba, int vectors)
 			 * selecting the same IRQ.
 			 */
 			start_cpu = cpumask_next(new_cpu, cpu_present_mask);
-			if (start_cpu == nr_cpumask_bits)
+			if (start_cpu >= nr_cpu_ids)
 				start_cpu = first_cpu;
 
 			lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
@@ -12648,7 +12648,7 @@ lpfc_cpu_affinity_check(struct lpfc_hba *phba, int vectors)
 				goto found_hdwq;
 			}
 			new_cpu = cpumask_next(new_cpu, cpu_present_mask);
-			if (new_cpu == nr_cpumask_bits)
+			if (new_cpu >= nr_cpu_ids)
 				new_cpu = first_cpu;
 		}
 
@@ -12663,7 +12663,7 @@ lpfc_cpu_affinity_check(struct lpfc_hba *phba, int vectors)
 				goto found_hdwq;
 
 			new_cpu = cpumask_next(new_cpu, cpu_present_mask);
-			if (new_cpu == nr_cpumask_bits)
+			if (new_cpu >= nr_cpu_ids)
 				new_cpu = first_cpu;
 		}
 
@@ -12674,7 +12674,7 @@ lpfc_cpu_affinity_check(struct lpfc_hba *phba, int vectors)
  found_hdwq:
 		/* We found an available entry, copy the IRQ info */
 		start_cpu = cpumask_next(new_cpu, cpu_present_mask);
-		if (start_cpu == nr_cpumask_bits)
+		if (start_cpu >= nr_cpu_ids)
 			start_cpu = first_cpu;
 		cpup->hdwq = new_cpup->hdwq;
  logit:
-- 
2.39.2

Re: [PATCH AUTOSEL 6.2 09/30] cpumask: fix incorrect cpumask scanning result checks

[Linus Torvalds]

On Sun, Mar 19, 2023 at 5:53 PM Sasha Levin <sashal@kernel.org> wrote:
>
> [ Upstream commit 8ca09d5fa3549d142c2080a72a4c70ce389163cd ]

These are technically real fixes, but they are really just "documented
behavior" fixes, and don't actually matter unless you also have
596ff4a09b89 ("cpumask: re-introduce constant-sized cpumask
optimizations"), which doesn't look like stable material.

And if somebody *does* decide to backport commit 596ff4a09b89, you
should then backport all of

  6015b1aca1a2 sched_getaffinity: don't assume 'cpumask_size()' is
fully initialized
  e7304080e0e5 cpumask: relax sanity checking constraints
  63355b9884b3 cpumask: be more careful with 'cpumask_setall()'
  8ca09d5fa354 cpumask: fix incorrect cpumask scanning result checks

but again, none of these matter as long as the constant-sized cpumask
optimized case doesn't exist.

(Technically, FORCE_NR_CPUS also does the constant-size optimizations
even before, but that will complain loudly if that constant size then
doesn't match nr_cpu_ids, so ..).

                   Linus

[PATCH AUTOSEL 6.2 10/30] scsi: target: iscsi: Fix an error message in iscsi_check_key()

[Sasha Levin]

From: Maurizio Lombardi <mlombard@redhat.com>

[ Upstream commit 6cc55c969b7ce8d85e09a636693d4126c3676c11 ]

The first half of the error message is printed by pr_err(), the second half
is printed by pr_debug(). The user will therefore see only the first part
of the message and will miss some useful information.

Link: https://lore.kernel.org/r/20230214141556.762047-1-mlombard@redhat.com
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/target/iscsi/iscsi_target_parameters.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_parameters.c b/drivers/target/iscsi/iscsi_target_parameters.c
index 2317fb077db0e..557516c642c3b 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.c
+++ b/drivers/target/iscsi/iscsi_target_parameters.c
@@ -1262,18 +1262,20 @@ static struct iscsi_param *iscsi_check_key(
 		return param;
 
 	if (!(param->phase & phase)) {
-		pr_err("Key \"%s\" may not be negotiated during ",
-				param->name);
+		char *phase_name;
+
 		switch (phase) {
 		case PHASE_SECURITY:
-			pr_debug("Security phase.\n");
+			phase_name = "Security";
 			break;
 		case PHASE_OPERATIONAL:
-			pr_debug("Operational phase.\n");
+			phase_name = "Operational";
 			break;
 		default:
-			pr_debug("Unknown phase.\n");
+			phase_name = "Unknown";
 		}
+		pr_err("Key \"%s\" may not be negotiated during %s phase.\n",
+				param->name, phase_name);
 		return NULL;
 	}
 
-- 
2.39.2

[PATCH AUTOSEL 6.2 11/30] scsi: qla2xxx: Add option to disable FC2 Target support

[Sasha Levin]

From: Daniel Wagner <dwagner@suse.de>

[ Upstream commit 877b03795fcf29ff2e2351f7e574ecc9b9c51732 ]

Commit 44c57f205876 ("scsi: qla2xxx: Changes to support FCP2 Target") added
support for FC2 Targets. Unfortunately, there are older setups which break
with this new feature enabled.

Allow to disable it via module option.

Link: https://lore.kernel.org/r/20230208152014.109214-1-dwagner@suse.de
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/qla2xxx/qla_gbl.h  |  1 +
 drivers/scsi/qla2xxx/qla_init.c |  3 ++-
 drivers/scsi/qla2xxx/qla_os.c   | 10 +++++++++-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_gbl.h b/drivers/scsi/qla2xxx/qla_gbl.h
index e3256e721be14..ee54207fc5319 100644
--- a/drivers/scsi/qla2xxx/qla_gbl.h
+++ b/drivers/scsi/qla2xxx/qla_gbl.h
@@ -192,6 +192,7 @@ extern int ql2xsecenable;
 extern int ql2xenforce_iocb_limit;
 extern int ql2xabts_wait_nvme;
 extern u32 ql2xnvme_queues;
+extern int ql2xfc2target;
 
 extern int qla2x00_loop_reset(scsi_qla_host_t *);
 extern void qla2x00_abort_all_cmds(scsi_qla_host_t *, int);
diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index 8f2a968793913..d506eb3a9b639 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -1841,7 +1841,8 @@ void qla2x00_handle_rscn(scsi_qla_host_t *vha, struct event_arg *ea)
 	case RSCN_PORT_ADDR:
 		fcport = qla2x00_find_fcport_by_nportid(vha, &ea->id, 1);
 		if (fcport) {
-			if (fcport->flags & FCF_FCP2_DEVICE &&
+			if (ql2xfc2target &&
+			    fcport->flags & FCF_FCP2_DEVICE &&
 			    atomic_read(&fcport->state) == FCS_ONLINE) {
 				ql_dbg(ql_dbg_disc, vha, 0x2115,
 				       "Delaying session delete for FCP2 portid=%06x %8phC ",
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 2d86f804872bf..0dc50b1b3dde5 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -360,6 +360,13 @@ MODULE_PARM_DESC(ql2xnvme_queues,
 	"1 - Minimum number of queues supported\n"
 	"8 - Default value");
 
+int ql2xfc2target = 1;
+module_param(ql2xfc2target, int, 0444);
+MODULE_PARM_DESC(qla2xfc2target,
+		  "Enables FC2 Target support. "
+		  "0 - FC2 Target support is disabled. "
+		  "1 - FC2 Target support is enabled (default).");
+
 static struct scsi_transport_template *qla2xxx_transport_template = NULL;
 struct scsi_transport_template *qla2xxx_transport_vport_template = NULL;
 
@@ -4075,7 +4082,8 @@ qla2x00_mark_all_devices_lost(scsi_qla_host_t *vha)
 	    "Mark all dev lost\n");
 
 	list_for_each_entry(fcport, &vha->vp_fcports, list) {
-		if (fcport->loop_id != FC_NO_LOOP_ID &&
+		if (ql2xfc2target &&
+		    fcport->loop_id != FC_NO_LOOP_ID &&
 		    (fcport->flags & FCF_FCP2_DEVICE) &&
 		    fcport->port_type == FCT_TARGET &&
 		    !qla2x00_reset_active(vha)) {
-- 
2.39.2

[PATCH AUTOSEL 6.2 12/30] scsi: hisi_sas: Check devm_add_action() return value

[Sasha Levin]

From: Kang Chen <void0red@gmail.com>

[ Upstream commit 06d1a90de60208054cca15ef200138cfdbb642a9 ]

In case devm_add_action() fails, check it in the caller of
interrupt_preinit_v3_hw().

Link: https://lore.kernel.org/r/20230227031030.893324-1-void0red@gmail.com
Signed-off-by: Kang Chen <void0red@gmail.com>
Acked-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 0c3fcb8078062..a63279f55d096 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -2495,8 +2495,7 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba)
 	hisi_hba->cq_nvecs = vectors - BASE_VECTORS_V3_HW;
 	shost->nr_hw_queues = hisi_hba->cq_nvecs;
 
-	devm_add_action(&pdev->dev, hisi_sas_v3_free_vectors, pdev);
-	return 0;
+	return devm_add_action(&pdev->dev, hisi_sas_v3_free_vectors, pdev);
 }
 
 static int interrupt_init_v3_hw(struct hisi_hba *hisi_hba)
-- 
2.39.2

[PATCH AUTOSEL 6.2 13/30] scsi: ufs: core: Add soft dependency on governor_simpleondemand

[Sasha Levin]

From: Adrien Thierry <athierry@redhat.com>

[ Upstream commit 2ebe16155dc8bd4e602cad5b5f65458d2eaa1a75 ]

The ufshcd driver uses simpleondemand governor for devfreq. Add it to the
list of ufshcd softdeps to allow userspace initramfs tools like dracut to
automatically pull the governor module into the initramfs together with UFS
drivers.

Link: https://lore.kernel.org/r/20230220140740.14379-1-athierry@redhat.com
Signed-off-by: Adrien Thierry <athierry@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/ufs/core/ufshcd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 2ddc1aba0ad75..edb93d2c5a781 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -10095,4 +10095,5 @@ module_exit(ufshcd_core_exit);
 MODULE_AUTHOR("Santosh Yaragnavi <santosh.sy@samsung.com>");
 MODULE_AUTHOR("Vinayak Holikatti <h.vinayak@samsung.com>");
 MODULE_DESCRIPTION("Generic UFS host controller driver Core");
+MODULE_SOFTDEP("pre: governor_simpleondemand");
 MODULE_LICENSE("GPL");
-- 
2.39.2

[PATCH AUTOSEL 6.2 14/30] scsi: lpfc: Check kzalloc() in lpfc_sli4_cgn_params_read()

[Sasha Levin]

From: Justin Tee <justin.tee@broadcom.com>

[ Upstream commit 312320b0e0ec21249a17645683fe5304d796aec1 ]

If kzalloc() fails in lpfc_sli4_cgn_params_read(), then we rely on
lpfc_read_object()'s routine to NULL check pdata.

Currently, an early return error is thrown from lpfc_read_object() to
protect us from NULL ptr dereference, but the errno code is -ENODEV.

Change the errno code to a more appropriate -ENOMEM.

Reported-by: Kang Chen <void0red@gmail.com>
Link: https://lore.kernel.org/all/20230226102338.3362585-1-void0red@gmail.com
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20230228044336.5195-1-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/lpfc/lpfc_init.c | 2 ++
 drivers/scsi/lpfc/lpfc_sli.c  | 4 ----
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 3fbd3bec26fc1..eeb73da754d0d 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -7235,6 +7235,8 @@ lpfc_sli4_cgn_params_read(struct lpfc_hba *phba)
 	/* Find out if the FW has a new set of congestion parameters. */
 	len = sizeof(struct lpfc_cgn_param);
 	pdata = kzalloc(len, GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
 	ret = lpfc_read_object(phba, (char *)LPFC_PORT_CFG_NAME,
 			       pdata, len);
 
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 55a0d4013439f..3aa7206537de7 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -22113,10 +22113,6 @@ lpfc_read_object(struct lpfc_hba *phba, char *rdobject, uint32_t *datap,
 	struct lpfc_dmabuf *pcmd;
 	u32 rd_object_name[LPFC_MBX_OBJECT_NAME_LEN_DW] = {0};
 
-	/* sanity check on queue memory */
-	if (!datap)
-		return -ENODEV;
-
 	mbox = mempool_alloc(phba->mbox_mem_pool, GFP_KERNEL);
 	if (!mbox)
 		return -ENOMEM;
-- 
2.39.2

[PATCH AUTOSEL 6.2 15/30] scsi: lpfc: Avoid usage of list iterator variable after loop

[Sasha Levin]

From: Jakob Koschel <jkl820.git@gmail.com>

[ Upstream commit 2850b23e9f9ae3696e472d2883ea1b43aafa884e ]

If the &epd_pool->list is empty when executing
lpfc_get_io_buf_from_expedite_pool() the function would return an invalid
pointer. Even in the case if the list is guaranteed to be populated, the
iterator variable should not be used after the loop to be more robust for
future changes.

Linus proposed to avoid any use of the list iterator variable after the
loop, in the attempt to move the list iterator variable declaration into
the macro to avoid any potential misuse after the loop [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jkl820.git@gmail.com>
Link: https://lore.kernel.org/r/20230301-scsi-lpfc-avoid-list-iterator-after-loop-v1-1-325578ae7561@gmail.com
Reviewed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/lpfc/lpfc_sli.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 3aa7206537de7..c0ddf55676a1f 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -21903,20 +21903,20 @@ lpfc_get_io_buf_from_private_pool(struct lpfc_hba *phba,
 static struct lpfc_io_buf *
 lpfc_get_io_buf_from_expedite_pool(struct lpfc_hba *phba)
 {
-	struct lpfc_io_buf *lpfc_ncmd;
+	struct lpfc_io_buf *lpfc_ncmd = NULL, *iter;
 	struct lpfc_io_buf *lpfc_ncmd_next;
 	unsigned long iflag;
 	struct lpfc_epd_pool *epd_pool;
 
 	epd_pool = &phba->epd_pool;
-	lpfc_ncmd = NULL;
 
 	spin_lock_irqsave(&epd_pool->lock, iflag);
 	if (epd_pool->count > 0) {
-		list_for_each_entry_safe(lpfc_ncmd, lpfc_ncmd_next,
+		list_for_each_entry_safe(iter, lpfc_ncmd_next,
 					 &epd_pool->list, list) {
-			list_del(&lpfc_ncmd->list);
+			list_del(&iter->list);
 			epd_pool->count--;
+			lpfc_ncmd = iter;
 			break;
 		}
 	}
-- 
2.39.2

[PATCH AUTOSEL 6.2 16/30] scsi: mpi3mr: ioctl timeout when disabling/enabling interrupt

[Sasha Levin]

From: Ranjan Kumar <ranjan.kumar@broadcom.com>

[ Upstream commit 02ca7da2919ada525fb424640205110e24646b50 ]

As part of Task Management handling, the driver will disable and enable the
MSIx index zero which belongs to the Admin reply queue. During this
transition the driver loses some interrupts and this leads to Admin request
and ioctl timeouts.

After enabling the interrupts, poll the Admin reply queue to avoid
timeouts.

Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Link: https://lore.kernel.org/r/20230228140835.4075-2-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/mpi3mr/mpi3mr.h    |  3 +++
 drivers/scsi/mpi3mr/mpi3mr_fw.c | 12 ++++++++++--
 drivers/scsi/mpi3mr/mpi3mr_os.c |  1 +
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/mpi3mr/mpi3mr.h b/drivers/scsi/mpi3mr/mpi3mr.h
index 8a438f248a820..68f29ffb05b82 100644
--- a/drivers/scsi/mpi3mr/mpi3mr.h
+++ b/drivers/scsi/mpi3mr/mpi3mr.h
@@ -903,6 +903,7 @@ struct scmd_priv {
  * @admin_reply_ephase:Admin reply queue expected phase
  * @admin_reply_base: Admin reply queue base virtual address
  * @admin_reply_dma: Admin reply queue base dma address
+ * @admin_reply_q_in_use: Queue is handled by poll/ISR
  * @ready_timeout: Controller ready timeout
  * @intr_info: Interrupt cookie pointer
  * @intr_info_count: Number of interrupt cookies
@@ -1056,6 +1057,7 @@ struct mpi3mr_ioc {
 	u8 admin_reply_ephase;
 	void *admin_reply_base;
 	dma_addr_t admin_reply_dma;
+	atomic_t admin_reply_q_in_use;
 
 	u32 ready_timeout;
 
@@ -1391,4 +1393,5 @@ void mpi3mr_add_event_wait_for_device_refresh(struct mpi3mr_ioc *mrioc);
 void mpi3mr_flush_drv_cmds(struct mpi3mr_ioc *mrioc);
 void mpi3mr_flush_cmds_for_unrecovered_controller(struct mpi3mr_ioc *mrioc);
 void mpi3mr_free_enclosure_list(struct mpi3mr_ioc *mrioc);
+int mpi3mr_process_admin_reply_q(struct mpi3mr_ioc *mrioc);
 #endif /*MPI3MR_H_INCLUDED*/
diff --git a/drivers/scsi/mpi3mr/mpi3mr_fw.c b/drivers/scsi/mpi3mr/mpi3mr_fw.c
index 758f7ca9e0ee8..4254e46a20f1a 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_fw.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_fw.c
@@ -415,7 +415,7 @@ static void mpi3mr_process_admin_reply_desc(struct mpi3mr_ioc *mrioc,
 		    le64_to_cpu(scsi_reply->sense_data_buffer_address));
 }
 
-static int mpi3mr_process_admin_reply_q(struct mpi3mr_ioc *mrioc)
+int mpi3mr_process_admin_reply_q(struct mpi3mr_ioc *mrioc)
 {
 	u32 exp_phase = mrioc->admin_reply_ephase;
 	u32 admin_reply_ci = mrioc->admin_reply_ci;
@@ -423,12 +423,17 @@ static int mpi3mr_process_admin_reply_q(struct mpi3mr_ioc *mrioc)
 	u64 reply_dma = 0;
 	struct mpi3_default_reply_descriptor *reply_desc;
 
+	if (!atomic_add_unless(&mrioc->admin_reply_q_in_use, 1, 1))
+		return 0;
+
 	reply_desc = (struct mpi3_default_reply_descriptor *)mrioc->admin_reply_base +
 	    admin_reply_ci;
 
 	if ((le16_to_cpu(reply_desc->reply_flags) &
-	    MPI3_REPLY_DESCRIPT_FLAGS_PHASE_MASK) != exp_phase)
+	    MPI3_REPLY_DESCRIPT_FLAGS_PHASE_MASK) != exp_phase) {
+		atomic_dec(&mrioc->admin_reply_q_in_use);
 		return 0;
+	}
 
 	do {
 		if (mrioc->unrecoverable)
@@ -454,6 +459,7 @@ static int mpi3mr_process_admin_reply_q(struct mpi3mr_ioc *mrioc)
 	writel(admin_reply_ci, &mrioc->sysif_regs->admin_reply_queue_ci);
 	mrioc->admin_reply_ci = admin_reply_ci;
 	mrioc->admin_reply_ephase = exp_phase;
+	atomic_dec(&mrioc->admin_reply_q_in_use);
 
 	return num_admin_replies;
 }
@@ -2605,6 +2611,7 @@ static int mpi3mr_setup_admin_qpair(struct mpi3mr_ioc *mrioc)
 	mrioc->admin_reply_ci = 0;
 	mrioc->admin_reply_ephase = 1;
 	mrioc->admin_reply_base = NULL;
+	atomic_set(&mrioc->admin_reply_q_in_use, 0);
 
 	if (!mrioc->admin_req_base) {
 		mrioc->admin_req_base = dma_alloc_coherent(&mrioc->pdev->dev,
@@ -4155,6 +4162,7 @@ void mpi3mr_memset_buffers(struct mpi3mr_ioc *mrioc)
 		memset(mrioc->admin_req_base, 0, mrioc->admin_req_q_sz);
 	if (mrioc->admin_reply_base)
 		memset(mrioc->admin_reply_base, 0, mrioc->admin_reply_q_sz);
+	atomic_set(&mrioc->admin_reply_q_in_use, 0);
 
 	if (mrioc->init_cmds.reply) {
 		memset(mrioc->init_cmds.reply, 0, sizeof(*mrioc->init_cmds.reply));
diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index 6eaeba41072cb..a794cc8a1c0b1 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -3720,6 +3720,7 @@ int mpi3mr_issue_tm(struct mpi3mr_ioc *mrioc, u8 tm_type,
 		mpi3mr_poll_pend_io_completions(mrioc);
 		mpi3mr_ioc_enable_intr(mrioc);
 		mpi3mr_poll_pend_io_completions(mrioc);
+		mpi3mr_process_admin_reply_q(mrioc);
 	}
 	switch (tm_type) {
 	case MPI3_SCSITASKMGMT_TASKTYPE_TARGET_RESET:
-- 
2.39.2

[PATCH AUTOSEL 6.2 17/30] scsi: mpi3mr: Driver unload crashes host when enhanced logging is enabled

[Sasha Levin]

From: Ranjan Kumar <ranjan.kumar@broadcom.com>

[ Upstream commit 5b06a7169c59ce0c77ef8b9c82aa07c478f82aac ]

Prevent driver from trying to dereference a NULL pointer in a debug print
while removing a device during driver unload.

Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Link: https://lore.kernel.org/r/20230228140835.4075-3-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/mpi3mr/mpi3mr_transport.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/mpi3mr/mpi3mr_transport.c b/drivers/scsi/mpi3mr/mpi3mr_transport.c
index 3b61815979dab..b795a325534d3 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_transport.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_transport.c
@@ -1552,7 +1552,8 @@ static void mpi3mr_sas_port_remove(struct mpi3mr_ioc *mrioc, u64 sas_address,
 
 	list_for_each_entry_safe(mr_sas_phy, next_phy,
 	    &mr_sas_port->phy_list, port_siblings) {
-		if ((mrioc->logging_level & MPI3_DEBUG_TRANSPORT_INFO))
+		if ((!mrioc->stop_drv_processing) &&
+		    (mrioc->logging_level & MPI3_DEBUG_TRANSPORT_INFO))
 			dev_info(&mr_sas_port->port->dev,
 			    "remove: sas_address(0x%016llx), phy(%d)\n",
 			    (unsigned long long)
-- 
2.39.2

[PATCH AUTOSEL 6.2 18/30] scsi: mpi3mr: Wait for diagnostic save during controller init

[Sasha Levin]

From: Ranjan Kumar <ranjan.kumar@broadcom.com>

[ Upstream commit 0a319f1629495d27879b7ebf6eee62b8cf6e4c37 ]

If a controller reset operation is triggered to recover the controller from
a fault state, then wait for the snapdump to be saved in the firmware
region before proceeding to reset the controller.

Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Link: https://lore.kernel.org/r/20230228140835.4075-4-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/mpi3mr/mpi3mr_fw.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/mpi3mr/mpi3mr_fw.c b/drivers/scsi/mpi3mr/mpi3mr_fw.c
index 4254e46a20f1a..fa903a70baac8 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_fw.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_fw.c
@@ -1198,7 +1198,7 @@ mpi3mr_revalidate_factsdata(struct mpi3mr_ioc *mrioc)
  */
 static int mpi3mr_bring_ioc_ready(struct mpi3mr_ioc *mrioc)
 {
-	u32 ioc_config, ioc_status, timeout;
+	u32 ioc_config, ioc_status, timeout, host_diagnostic;
 	int retval = 0;
 	enum mpi3mr_iocstate ioc_state;
 	u64 base_info;
@@ -1252,6 +1252,23 @@ static int mpi3mr_bring_ioc_ready(struct mpi3mr_ioc *mrioc)
 			    retval, mpi3mr_iocstate_name(ioc_state));
 	}
 	if (ioc_state != MRIOC_STATE_RESET) {
+		if (ioc_state == MRIOC_STATE_FAULT) {
+			timeout = MPI3_SYSIF_DIAG_SAVE_TIMEOUT * 10;
+			mpi3mr_print_fault_info(mrioc);
+			do {
+				host_diagnostic =
+					readl(&mrioc->sysif_regs->host_diagnostic);
+				if (!(host_diagnostic &
+				      MPI3_SYSIF_HOST_DIAG_SAVE_IN_PROGRESS))
+					break;
+				if (!pci_device_is_present(mrioc->pdev)) {
+					mrioc->unrecoverable = 1;
+					ioc_err(mrioc, "controller is not present at the bringup\n");
+					goto out_device_not_present;
+				}
+				msleep(100);
+			} while (--timeout);
+		}
 		mpi3mr_print_fault_info(mrioc);
 		ioc_info(mrioc, "issuing soft reset to bring to reset state\n");
 		retval = mpi3mr_issue_reset(mrioc,
-- 
2.39.2

[PATCH AUTOSEL 6.2 19/30] scsi: mpi3mr: Return proper values for failures in firmware init path

[Sasha Levin]

From: Ranjan Kumar <ranjan.kumar@broadcom.com>

[ Upstream commit ba8a9ba41fbde250fd8b0ed1e5dad0dc9318df46 ]

Return proper non-zero return values for all the cases when the controller
initialization and re-initialization fails.

Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Link: https://lore.kernel.org/r/20230228140835.4075-5-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/mpi3mr/mpi3mr_fw.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/mpi3mr/mpi3mr_fw.c b/drivers/scsi/mpi3mr/mpi3mr_fw.c
index fa903a70baac8..29acf6111db30 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_fw.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_fw.c
@@ -3840,8 +3840,10 @@ int mpi3mr_init_ioc(struct mpi3mr_ioc *mrioc)
 	dprint_init(mrioc, "allocating config page buffers\n");
 	mrioc->cfg_page = dma_alloc_coherent(&mrioc->pdev->dev,
 	    MPI3MR_DEFAULT_CFG_PAGE_SZ, &mrioc->cfg_page_dma, GFP_KERNEL);
-	if (!mrioc->cfg_page)
+	if (!mrioc->cfg_page) {
+		retval = -1;
 		goto out_failed_noretry;
+	}
 
 	mrioc->cfg_page_sz = MPI3MR_DEFAULT_CFG_PAGE_SZ;
 
@@ -3903,8 +3905,10 @@ int mpi3mr_init_ioc(struct mpi3mr_ioc *mrioc)
 		dprint_init(mrioc, "allocating memory for throttle groups\n");
 		sz = sizeof(struct mpi3mr_throttle_group_info);
 		mrioc->throttle_groups = kcalloc(mrioc->num_io_throttle_group, sz, GFP_KERNEL);
-		if (!mrioc->throttle_groups)
+		if (!mrioc->throttle_groups) {
+			retval = -1;
 			goto out_failed_noretry;
+		}
 	}
 
 	retval = mpi3mr_enable_events(mrioc);
@@ -3924,6 +3928,7 @@ int mpi3mr_init_ioc(struct mpi3mr_ioc *mrioc)
 		mpi3mr_memset_buffers(mrioc);
 		goto retry_init;
 	}
+	retval = -1;
 out_failed_noretry:
 	ioc_err(mrioc, "controller initialization failed\n");
 	mpi3mr_issue_reset(mrioc, MPI3_SYSIF_HOST_DIAG_RESET_ACTION_DIAG_FAULT,
@@ -4036,6 +4041,7 @@ int mpi3mr_reinit_ioc(struct mpi3mr_ioc *mrioc, u8 is_resume)
 		ioc_err(mrioc,
 		    "cannot create minimum number of operational queues expected:%d created:%d\n",
 		    mrioc->shost->nr_hw_queues, mrioc->num_op_reply_q);
+		retval = -1;
 		goto out_failed_noretry;
 	}
 
@@ -4102,6 +4108,7 @@ int mpi3mr_reinit_ioc(struct mpi3mr_ioc *mrioc, u8 is_resume)
 		mpi3mr_memset_buffers(mrioc);
 		goto retry_init;
 	}
+	retval = -1;
 out_failed_noretry:
 	ioc_err(mrioc, "controller %s is failed\n",
 	    (is_resume)?"resume":"re-initialization");
-- 
2.39.2

[PATCH AUTOSEL 6.2 20/30] scsi: mpi3mr: NVMe command size greater than 8K fails

[Sasha Levin]

From: Ranjan Kumar <ranjan.kumar@broadcom.com>

[ Upstream commit 4f297e856a7b5da2f2c66a12e739666e23943560 ]

A wrong variable is checked while populating PRP entries in the PRP page
and this results in failure. No PRP entries in the PRP page were
successfully created and any NVMe Encapsulated commands with PRP of size
greater than 8K failed.

Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Link: https://lore.kernel.org/r/20230228140835.4075-6-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/mpi3mr/mpi3mr_app.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/mpi3mr/mpi3mr_app.c b/drivers/scsi/mpi3mr/mpi3mr_app.c
index bff6377023979..d10c6afb7f9cd 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_app.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_app.c
@@ -886,7 +886,7 @@ static int mpi3mr_build_nvme_prp(struct mpi3mr_ioc *mrioc,
 			 * each time through the loop.
 			 */
 			*prp_entry = cpu_to_le64(dma_addr);
-			if (*prp1_entry & sgemod_mask) {
+			if (*prp_entry & sgemod_mask) {
 				dprint_bsg_err(mrioc,
 				    "%s: PRP address collides with SGE modifier\n",
 				    __func__);
@@ -895,7 +895,7 @@ static int mpi3mr_build_nvme_prp(struct mpi3mr_ioc *mrioc,
 			*prp_entry &= ~sgemod_mask;
 			*prp_entry |= sgemod_val;
 			prp_entry++;
-			prp_entry_dma++;
+			prp_entry_dma += prp_size;
 		}
 
 		/*
-- 
2.39.2

[PATCH AUTOSEL 6.2 21/30] scsi: mpi3mr: Bad drive in topology results kernel crash

[Sasha Levin]

From: Ranjan Kumar <ranjan.kumar@broadcom.com>

[ Upstream commit 8e45183978d64699df639e795235433a60f35047 ]

When the SAS Transport Layer support is enabled and a device exposed to
the OS by the driver fails INQUIRY commands, the driver frees up the memory
allocated for an internal HBA port data structure. However, in some places,
the reference to the freed memory is not cleared. When the firmware sends
the Device Info change event for the same device again, the freed memory is
accessed and that leads to memory corruption and OS crash.

Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Link: https://lore.kernel.org/r/20230228140835.4075-7-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/mpi3mr/mpi3mr_transport.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/mpi3mr/mpi3mr_transport.c b/drivers/scsi/mpi3mr/mpi3mr_transport.c
index b795a325534d3..be25f242fa794 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_transport.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_transport.c
@@ -2358,15 +2358,16 @@ int mpi3mr_report_tgtdev_to_sas_transport(struct mpi3mr_ioc *mrioc,
 	tgtdev->host_exposed = 1;
 	if (!mpi3mr_sas_port_add(mrioc, tgtdev->dev_handle,
 	    sas_address_parent, hba_port)) {
-		tgtdev->host_exposed = 0;
 		retval = -1;
-	} else if ((!tgtdev->starget)) {
-		if (!mrioc->is_driver_loading)
+		} else if ((!tgtdev->starget) && (!mrioc->is_driver_loading)) {
 			mpi3mr_sas_port_remove(mrioc, sas_address,
 			    sas_address_parent, hba_port);
-		tgtdev->host_exposed = 0;
 		retval = -1;
 	}
+	if (retval) {
+		tgtdev->dev_spec.sas_sata_inf.hba_port = NULL;
+		tgtdev->host_exposed = 0;
+	}
 	return retval;
 }
 
@@ -2395,6 +2396,7 @@ void mpi3mr_remove_tgtdev_from_sas_transport(struct mpi3mr_ioc *mrioc,
 	mpi3mr_sas_port_remove(mrioc, sas_address, sas_address_parent,
 	    hba_port);
 	tgtdev->host_exposed = 0;
+	tgtdev->dev_spec.sas_sata_inf.hba_port = NULL;
 }
 
 /**
@@ -2451,7 +2453,7 @@ static u8 mpi3mr_get_port_id_by_rphy(struct mpi3mr_ioc *mrioc, struct sas_rphy *
 
 		tgtdev = __mpi3mr_get_tgtdev_by_addr_and_rphy(mrioc,
 			    rphy->identify.sas_address, rphy);
-		if (tgtdev) {
+		if (tgtdev && tgtdev->dev_spec.sas_sata_inf.hba_port) {
 			port_id =
 				tgtdev->dev_spec.sas_sata_inf.hba_port->port_id;
 			mpi3mr_tgtdev_put(tgtdev);
-- 
2.39.2

[PATCH AUTOSEL 6.2 22/30] scsi: storvsc: Handle BlockSize change in Hyper-V VHD/VHDX file

[Sasha Levin]

From: Michael Kelley <mikelley@microsoft.com>

[ Upstream commit 11d9874c4204a785f43d899a1ab12f9dc8d9de3e ]

Hyper-V uses a VHD or VHDX file on the host as the underlying storage for a
virtual disk.  The VHD/VHDX file format is a sparse format where real disk
space on the host is assigned in chunks that the VHD/VHDX file format calls
the BlockSize.  This BlockSize is not to be confused with the 512-byte (or
4096-byte) sector size of the underlying storage device.  The default block
size for a new VHD/VHDX file is 32 Mbytes.  When a guest VM touches any
disk space within a 32 Mbyte chunk of the VHD/VHDX file, Hyper-V allocates
32 Mbytes of real disk space for that section of the VHD/VHDX. Similarly,
if a discard operation is done that covers an entire 32 Mbyte chunk,
Hyper-V will free the real disk space for that portion of the VHD/VHDX.
This BlockSize is surfaced in Linux as the "discard_granularity" in
/sys/block/sd<x>/queue, which makes sense.

Hyper-V also has differencing disks that can overlay a VHD/VHDX file to
capture changes to the VHD/VHDX while preserving the original VHD/VHDX.
One example of this differencing functionality is for VM snapshots.  When a
snapshot is created, a differencing disk is created.  If the snapshot is
rolled back, Hyper-V can just delete the differencing disk, and the VM will
see the original disk contents at the time the snapshot was taken.
Differencing disks are used in other scenarios as well.

The BlockSize for a differencing disk defaults to 2 Mbytes, not 32 Mbytes.
The smaller default is used because changes to differencing disks are
typically scattered all over, and Hyper-V doesn't want to allocate 32
Mbytes of real disk space for a stray write here or there.  The smaller
BlockSize provides more efficient use of real disk space.

When a differencing disk is added to a VHD/VHDX, Hyper-V reports
UNIT_ATTENTION with a sense code indicating "Operating parameters have
changed", because the value of discard_granularity should be changed to 2
Mbytes. When the differencing disk is removed, discard_granularity should
be changed back to 32 Mbytes.  However, current code simply reports a
message from scsi_report_sense() and the value of
/sys/block/sd<x>/queue/discard_granularity is not updated. The message
isn't very actionable by a sysadmin.

Fix this by having the storvsc driver check for the sense code indicating
that the underly VHD/VHDX block size has changed, and do a rescan of the
device to pick up the new discard_granularity.  With this change the entire
transition to/from differencing disks is handled automatically and
transparently, with no confusing messages being output.

Link: https://lore.kernel.org/r/1677516514-86060-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/storvsc_drv.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 22705eb781b0e..2bf25e80b29a8 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -987,6 +987,22 @@ static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 				goto do_work;
 			}
 
+			/*
+			 * Check for "Operating parameters have changed"
+			 * due to Hyper-V changing the VHD/VHDX BlockSize
+			 * when adding/removing a differencing disk. This
+			 * causes discard_granularity to change, so do a
+			 * rescan to pick up the new granularity. We don't
+			 * want scsi_report_sense() to output a message
+			 * that a sysadmin wouldn't know what to do with.
+			 */
+			if ((asc == 0x3f) && (ascq != 0x03) &&
+					(ascq != 0x0e)) {
+				process_err_fn = storvsc_device_scan;
+				set_host_byte(scmnd, DID_REQUEUE);
+				goto do_work;
+			}
+
 			/*
 			 * Otherwise, let upper layer deal with the
 			 * error when sense message is present
-- 
2.39.2