On Fri 25-07-25 10:15:50, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@xxxxxxxxxx>
>
> 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 <linux@xxxxxxxxxxxx>
> Closes: https://lore.kernel.org/linux-ext4/b0635ad0-7ebf-4152-a69b-58e7e87d5085@xxxxxxxxxxxx/
> Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> 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
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
