Messages in this thread | | | Subject | Re: [PATCH 1/4] erofs: fix setting up pcluster for temporary pages | From | Vladimir Zapolskiy <> | Date | Fri, 30 Oct 2020 14:20:31 +0200 |
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Hello Gao Xiang,
On 10/22/20 5:57 PM, Gao Xiang via Linux-erofs wrote: > From: Gao Xiang <hsiangkao@redhat.com> > > pcluster should be only set up for all managed pages instead of > temporary pages. Since it currently uses page->mapping to identify, > the impact is minor for now. > > Fixes: 5ddcee1f3a1c ("erofs: get rid of __stagingpage_alloc helper") > Cc: <stable@vger.kernel.org> # 5.5+ > Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
I was looking exactly at this problem recently, my change is one-to-one to your fix, thus I can provide a tag:
Tested-by: Vladimir Zapolskiy <vladimir@tuxera.com>
The fixed problem is minor, but the kernel log becomes polluted, if a page allocation debug option is enabled:
% md5sum ~/erofs/testfile BUG: Bad page state in process kworker/u9:0 pfn:687de page:0000000057b8bcb4 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x687de flags: 0x4000000000002000(private) raw: 4000000000002000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 ffff888066758690 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set Modules linked in: CPU: 1 PID: 602 Comm: kworker/u9:0 Not tainted 5.9.1 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 Workqueue: erofs_unzipd z_erofs_decompressqueue_work Call Trace: dump_stack+0x84/0xba bad_page.cold+0xac/0xb1 check_free_page_bad+0xb0/0xc0 free_pcp_prepare+0x2c8/0x2d0 free_unref_page+0x18/0xf0 put_pages_list+0x11a/0x120 z_erofs_decompressqueue_work+0xc9/0x110 ? z_erofs_decompress_pcluster.isra.0+0xf10/0xf10 ? read_word_at_a_time+0x12/0x20 ? strscpy+0xc7/0x1a0 process_one_work+0x30c/0x730 worker_thread+0x91/0x640 ? __kasan_check_read+0x11/0x20 ? rescuer_thread+0x8a0/0x8a0 kthread+0x1dd/0x200 ? kthread_unpark+0xa0/0xa0 ret_from_fork+0x1f/0x30 Disabling lock debugging due to kernel taint
-- Best wishes, Vladimir
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