From: Zhang Yi ext4_mb_avg_fragment_size_destroy() requires a valid sbi->s_sb, mb_set_largest_free_order() requires the parameter bb_largest_free_order to be initialized, and mb_update_avg_fragment_size() requires the parameter bb_avg_fragment_size_order to be initialized. But the test_new_blocks_simple kunit tests do not init these parameters, and trigger the following crash issue. Pid: 20, comm: kunit_try_catch Tainted: G W N 6.16.0-rc4-ga8a47fa84cc2 RIP: 0033:ext4_mb_release+0x1fc/0x400 RSP: 00000000a0883ed0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000060a1e400 RCX: 0000000000000002 RDX: 0000000060058fa0 RSI: 0000000000000002 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000002 R10: 00000000a0883e68 R11: 0000000060374bb0 R12: 000000006012eff0 R13: 00000000603763e0 R14: 0000000060ad92d8 R15: 0000000060c051c0 Kernel panic - not syncing: Segfault with no mm CPU: 0 UID: 0 PID: 20 Comm: kunit_try_catch Tainted: G W N 6.16.0-rc4-ga8a47fa84cc2 #47 NONE Tainted: [W]=WARN, [N]=TEST Stack: 60134c30 400000004 60864000 6092a3c0 00000001 a0803d40 a0803b28 6012eff0 605990e8 60085be0 60864000 602167aa Call Trace: [<60134c30>] ? kmem_cache_free+0x0/0x3d0 [<6012eff0>] ? kfree+0x0/0x290 [<60085be0>] ? to_kthread+0x0/0x40 [<602167aa>] ? mbt_kunit_exit+0x2a/0xe0 [<60085be0>] ? to_kthread+0x0/0x40 [<602acd50>] ? kunit_generic_run_threadfn_adapter+0x0/0x30 [<60085be0>] ? to_kthread+0x0/0x40 [<602aaa8a>] ? kunit_try_run_case_cleanup+0x2a/0x40 [<602acd62>] ? kunit_generic_run_threadfn_adapter+0x12/0x30 [<600862c1>] ? kthread+0xf1/0x250 [<6004a521>] ? new_thread_handler+0x41/0x60 Fixes: bbe11dd13a3f ("ext4: fix largest free orders lists corruption on mb_optimize_scan switch") Fixes: 458bfb991155 ("ext4: convert free groups order lists to xarrays") Reported-by: Guenter Roeck Closes: https://lore.kernel.org/linux-ext4/b0635ad0-7ebf-4152-a69b-58e7e87d5085@roeck-us.net/ Tested-by: Guenter Roeck Signed-off-by: Zhang Yi --- fs/ext4/mballoc-test.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c index d634c12f1984..a9416b20ff64 100644 --- a/fs/ext4/mballoc-test.c +++ b/fs/ext4/mballoc-test.c @@ -155,6 +155,7 @@ static struct super_block *mbt_ext4_alloc_super_block(void) bgl_lock_init(sbi->s_blockgroup_lock); sbi->s_es = &fsb->es; + sbi->s_sb = sb; sb->s_fs_info = sbi; up_write(&sb->s_umount); @@ -802,6 +803,8 @@ static void test_mb_mark_used(struct kunit *test) KUNIT_ASSERT_EQ(test, ret, 0); grp->bb_free = EXT4_CLUSTERS_PER_GROUP(sb); + grp->bb_largest_free_order = -1; + grp->bb_avg_fragment_size_order = -1; mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT); for (i = 0; i < TEST_RANGE_COUNT; i++) test_mb_mark_used_range(test, &e4b, ranges[i].start, @@ -875,6 +878,8 @@ static void test_mb_free_blocks(struct kunit *test) ext4_unlock_group(sb, TEST_GOAL_GROUP); grp->bb_free = 0; + grp->bb_largest_free_order = -1; + grp->bb_avg_fragment_size_order = -1; memset(bitmap, 0xff, sb->s_blocksize); mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT); -- 2.46.1