Merge tag 'block-6.19-20260102' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull block fixes from Jens Axboe:

 - Scan partition tables asynchronously for ublk, similarly to how nvme
   does it. This avoids potential deadlocks, which is why nvme does it
   that way too. Includes a set of selftests as well.

 - MD pull request via Yu:
     - Fix null-pointer dereference in raid5 sysfs group_thread_cnt
       store (Tuo Li)
     - Fix possible mempool corruption during raid1 raid_disks update
       via sysfs (FengWei Shih)
     - Fix logical_block_size configuration being overwritten during
       super_1_validate() (Li Nan)
     - Fix forward incompatibility with configurable logical block size:
       arrays assembled on new kernels could not be assembled on older
       kernels (v6.18 and before) due to non-zero reserved pad rejection
       (Li Nan)
     - Fix static checker warning about iterator not incremented (Li Nan)

 - Skip CPU offlining notifications on unmapped hardware queues

 - bfq-iosched block stats fix

 - Fix outdated comment in bfq-iosched

* tag 'block-6.19-20260102' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  block, bfq: update outdated comment
  blk-mq: skip CPU offline notify on unmapped hctx
  selftests/ublk: fix Makefile to rebuild on header changes
  selftests/ublk: add test for async partition scan
  ublk: scan partition in async way
  block,bfq: fix aux stat accumulation destination
  md: Fix forward incompatibility from configurable logical block size
  md: Fix logical_block_size configuration being overwritten
  md: suspend array while updating raid_disks via sysfs
  md/raid5: fix possible null-pointer dereferences in raid5_store_group_thread_cnt()
  md: Fix static checker warning in analyze_sbs

3 files changed, 83 insertions, 6 deletions

diff --git a/tools/testing/selftests/ublk/Makefile b/tools/testing/selftests/ublk/Makefile
index 837977b62417..06ba6fde098d 100644
--- a/tools/testing/selftests/ublk/Makefile
+++ b/tools/testing/selftests/ublk/Makefile
@@ -22,6 +22,7 @@ TEST_PROGS += test_generic_11.sh
 TEST_PROGS += test_generic_12.sh
 TEST_PROGS += test_generic_13.sh
 TEST_PROGS += test_generic_14.sh
+TEST_PROGS += test_generic_15.sh
 
 TEST_PROGS += test_null_01.sh
 TEST_PROGS += test_null_02.sh
@@ -50,10 +51,10 @@ TEST_PROGS += test_stress_07.sh
 
 TEST_GEN_PROGS_EXTENDED = kublk
 
+LOCAL_HDRS += $(wildcard *.h)
 include ../lib.mk
 
-$(TEST_GEN_PROGS_EXTENDED): kublk.c null.c file_backed.c common.c stripe.c \
-	fault_inject.c
+$(TEST_GEN_PROGS_EXTENDED): $(wildcard *.c)
 
 check:
 	shellcheck -x -f gcc *.sh
diff --git a/tools/testing/selftests/ublk/test_common.sh b/tools/testing/selftests/ublk/test_common.sh
index 6f1c042de40e..ea9a5f3eb70a 100755
--- a/tools/testing/selftests/ublk/test_common.sh
+++ b/tools/testing/selftests/ublk/test_common.sh
@@ -178,8 +178,9 @@ _have_feature()
 _create_ublk_dev() {
 	local dev_id;
 	local cmd=$1
+	local settle=$2
 
-	shift 1
+	shift 2
 
 	if [ ! -c /dev/ublk-control ]; then
 		return ${UBLK_SKIP_CODE}
@@ -194,7 +195,10 @@ _create_ublk_dev() {
 		echo "fail to add ublk dev $*"
 		return 255
 	fi
-	udevadm settle
+
+	if [ "$settle" = "yes" ]; then
+		udevadm settle
+	fi
 
 	if [[ "$dev_id" =~ ^[0-9]+$ ]]; then
 		echo "${dev_id}"
@@ -204,14 +208,18 @@ _create_ublk_dev() {
 }
 
 _add_ublk_dev() {
-	_create_ublk_dev "add" "$@"
+	_create_ublk_dev "add" "yes" "$@"
+}
+
+_add_ublk_dev_no_settle() {
+	_create_ublk_dev "add" "no" "$@"
 }
 
 _recover_ublk_dev() {
 	local dev_id
 	local state
 
-	dev_id=$(_create_ublk_dev "recover" "$@")
+	dev_id=$(_create_ublk_dev "recover" "yes" "$@")
 	for ((j=0;j<20;j++)); do
 		state=$(_get_ublk_dev_state "${dev_id}")
 		[ "$state" == "LIVE" ] && break
diff --git a/tools/testing/selftests/ublk/test_generic_15.sh b/tools/testing/selftests/ublk/test_generic_15.sh
new file mode 100755
index 000000000000..76379362e0a2
--- /dev/null
+++ b/tools/testing/selftests/ublk/test_generic_15.sh
@@ -0,0 +1,68 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh
+
+TID="generic_15"
+ERR_CODE=0
+
+_test_partition_scan_no_hang()
+{
+	local recovery_flag=$1
+	local expected_state=$2
+	local dev_id
+	local state
+	local daemon_pid
+	local start_time
+	local elapsed
+
+	# Create ublk device with fault_inject target and very large delay
+	# to simulate hang during partition table read
+	# --delay_us 60000000 = 60 seconds delay
+	# Use _add_ublk_dev_no_settle to avoid udevadm settle hang waiting
+	# for partition scan events to complete
+	if [ "$recovery_flag" = "yes" ]; then
+		echo "Testing partition scan with recovery support..."
+		dev_id=$(_add_ublk_dev_no_settle -t fault_inject -q 1 -d 1 --delay_us 60000000 -r 1)
+	else
+		echo "Testing partition scan without recovery..."
+		dev_id=$(_add_ublk_dev_no_settle -t fault_inject -q 1 -d 1 --delay_us 60000000)
+	fi
+
+	_check_add_dev "$TID" $?
+
+	# The add command should return quickly because partition scan is async.
+	# Now sleep briefly to let the async partition scan work start and hit
+	# the delay in the fault_inject handler.
+	sleep 1
+
+	# Kill the ublk daemon while partition scan is potentially blocked
+	# And check state transitions properly
+	start_time=${SECONDS}
+	daemon_pid=$(_get_ublk_daemon_pid "${dev_id}")
+	state=$(__ublk_kill_daemon "${dev_id}" "${expected_state}")
+	elapsed=$((SECONDS - start_time))
+
+	# Verify the device transitioned to expected state
+	if [ "$state" != "${expected_state}" ]; then
+		echo "FAIL: Device state is $state, expected ${expected_state}"
+		ERR_CODE=255
+		${UBLK_PROG} del -n "${dev_id}" > /dev/null 2>&1
+		return
+	fi
+	echo "PASS: Device transitioned to ${expected_state} in ${elapsed}s without hanging"
+
+	# Clean up the device
+	${UBLK_PROG} del -n "${dev_id}" > /dev/null 2>&1
+}
+
+_prep_test "partition_scan" "verify async partition scan prevents IO hang"
+
+# Test 1: Without recovery support - should transition to DEAD
+_test_partition_scan_no_hang "no" "DEAD"
+
+# Test 2: With recovery support - should transition to QUIESCED
+_test_partition_scan_no_hang "yes" "QUIESCED"
+
+_cleanup_test "partition_scan"
+_show_result $TID $ERR_CODE