From: "ruansy.fnst@fujitsu.com" <ruansy.fnst@fujitsu.com>
To: zhong jiang <zhongjiang-ali@linux.alibaba.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-xfs@vger.kernel.org" <linux-xfs@vger.kernel.org>,
"linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"dm-devel@redhat.com" <dm-devel@redhat.com>
Cc: "darrick.wong@oracle.com" <darrick.wong@oracle.com>,
"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
"david@fromorbit.com" <david@fromorbit.com>,
"hch@lst.de" <hch@lst.de>, "agk@redhat.com" <agk@redhat.com>,
"snitzer@redhat.com" <snitzer@redhat.com>,
"rgoldwyn@suse.de" <rgoldwyn@suse.de>,
"qi.fuli@fujitsu.com" <qi.fuli@fujitsu.com>,
"y-goto@fujitsu.com" <y-goto@fujitsu.com>
Subject: RE: [PATCH v3 05/11] mm, fsdax: Refactor memory-failure handler for dax mapping
Date: Wed, 17 Mar 2021 03:46:25 +0000 [thread overview]
Message-ID: <OSAPR01MB2913D9A487C1D55171C5059EF46A9@OSAPR01MB2913.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <e1be1767-f9c0-e17a-5c14-22bb2f0ca5aa@linux.alibaba.com>
> -----Original Message-----
> From: zhong jiang <zhongjiang-ali@linux.alibaba.com>
> Subject: Re: [PATCH v3 05/11] mm, fsdax: Refactor memory-failure handler for
> dax mapping
>
> > +int mf_dax_mapping_kill_procs(struct address_space *mapping, pgoff_t
> > +index, int flags) {
> > + const bool unmap_success = true;
> > + unsigned long pfn, size = 0;
> > + struct to_kill *tk;
> > + LIST_HEAD(to_kill);
> > + int rc = -EBUSY;
> > + loff_t start;
> > +
> > + /* load the pfn of the dax mapping file */
> > + pfn = dax_load_pfn(mapping, index);
> > + if (!pfn)
> > + return rc;
> > + /*
> > + * Unlike System-RAM there is no possibility to swap in a
> > + * different physical page at a given virtual address, so all
> > + * userspace consumption of ZONE_DEVICE memory necessitates
> > + * SIGBUS (i.e. MF_MUST_KILL)
> > + */
> > + flags |= MF_ACTION_REQUIRED | MF_MUST_KILL;
>
> MF_ACTION_REQUIRED only kill the current execution context. A page can be
> shared when reflink file be mapped by different process. We can not kill all
> process shared the page. Other process still can access the posioned page ?
AFAIK, the other processes will receive a SIGBUS when accessing this corrupted range. But I didn't add a testcase for this condition. I'll test it. Thanks for pointing out.
--
Thanks,
Ruan Shiyang.
>
> Thanks,
> zhong jiang
>
> > + collect_procs_file(pfn_to_page(pfn), mapping, index, &to_kill,
> > + flags & MF_ACTION_REQUIRED);
> > +
> > + list_for_each_entry(tk, &to_kill, nd)
> > + if (tk->size_shift)
> > + size = max(size, 1UL << tk->size_shift);
> > + if (size) {
> > + /*
> > + * Unmap the largest mapping to avoid breaking up
> > + * device-dax mappings which are constant size. The
> > + * actual size of the mapping being torn down is
> > + * communicated in siginfo, see kill_proc()
> > + */
> > + start = (index << PAGE_SHIFT) & ~(size - 1);
> > + unmap_mapping_range(mapping, start, start + size, 0);
> > + }
> > +
> > + kill_procs(&to_kill, flags & MF_MUST_KILL, !unmap_success,
> > + pfn, flags);
> > + rc = 0;
> > + return rc;
> > +}
> > +EXPORT_SYMBOL_GPL(mf_dax_mapping_kill_procs);
> > +
> > static int memory_failure_hugetlb(unsigned long pfn, int flags)
> > {
> > struct page *p = pfn_to_page(pfn);
> > @@ -1297,7 +1346,7 @@ static int memory_failure_dev_pagemap(unsigned
> long pfn, int flags,
> > const bool unmap_success = true;
> > unsigned long size = 0;
> > struct to_kill *tk;
> > - LIST_HEAD(tokill);
> > + LIST_HEAD(to_kill);
> > int rc = -EBUSY;
> > loff_t start;
> > dax_entry_t cookie;
> > @@ -1345,9 +1394,10 @@ static int
> memory_failure_dev_pagemap(unsigned long pfn, int flags,
> > * SIGBUS (i.e. MF_MUST_KILL)
> > */
> > flags |= MF_ACTION_REQUIRED | MF_MUST_KILL;
> > - collect_procs(page, &tokill, flags & MF_ACTION_REQUIRED);
> > + collect_procs_file(page, page->mapping, page->index, &to_kill,
> > + flags & MF_ACTION_REQUIRED);
> >
> > - list_for_each_entry(tk, &tokill, nd)
> > + list_for_each_entry(tk, &to_kill, nd)
> > if (tk->size_shift)
> > size = max(size, 1UL << tk->size_shift);
> > if (size) {
> > @@ -1360,7 +1410,7 @@ static int memory_failure_dev_pagemap(unsigned
> long pfn, int flags,
> > start = (page->index << PAGE_SHIFT) & ~(size - 1);
> > unmap_mapping_range(page->mapping, start, start + size, 0);
> > }
> > - kill_procs(&tokill, flags & MF_MUST_KILL, !unmap_success, pfn, flags);
> > + kill_procs(&to_kill, flags & MF_MUST_KILL, !unmap_success, pfn,
> > +flags);
> > rc = 0;
> > unlock:
> > dax_unlock_page(page, cookie);
>
next prev parent reply other threads:[~2021-03-17 3:47 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-08 10:55 [PATCH v3 00/11] fsdax: introduce fs query to support reflink Shiyang Ruan
2021-02-08 10:55 ` [PATCH v3 01/11] pagemap: Introduce ->memory_failure() Shiyang Ruan
2021-02-10 13:20 ` Christoph Hellwig
2021-03-06 20:36 ` Dan Williams
2021-03-08 3:38 ` ruansy.fnst
2021-03-08 5:23 ` Dan Williams
2021-03-08 11:34 ` ruansy.fnst
2021-03-08 18:01 ` Dan Williams
2021-03-12 10:18 ` ruansy.fnst
2021-03-19 2:17 ` ruansy.fnst
2021-03-24 2:19 ` Dan Williams
2021-03-24 7:47 ` Christoph Hellwig
2021-03-24 16:37 ` Dan Williams
2021-03-24 17:39 ` Christoph Hellwig
2021-03-24 18:00 ` Dan Williams
2021-02-08 10:55 ` [PATCH v3 02/11] blk: Introduce ->corrupted_range() for block device Shiyang Ruan
2021-02-10 13:21 ` Christoph Hellwig
2021-03-04 22:42 ` Darrick J. Wong
2021-03-05 6:10 ` Christoph Hellwig
2021-02-08 10:55 ` [PATCH v3 03/11] fs: Introduce ->corrupted_range() for superblock Shiyang Ruan
2021-02-08 10:55 ` [PATCH v3 04/11] block_dev: Introduce bd_corrupted_range() for block device Shiyang Ruan
2021-02-08 10:55 ` [PATCH v3 05/11] mm, fsdax: Refactor memory-failure handler for dax mapping Shiyang Ruan
2021-02-10 13:33 ` Christoph Hellwig
2021-02-17 2:56 ` Ruan Shiyang
2021-02-18 8:32 ` Christoph Hellwig
2021-02-18 8:59 ` Ruan Shiyang
2021-03-16 3:21 ` zhong jiang
2021-03-17 3:46 ` ruansy.fnst [this message]
2021-02-08 10:55 ` [PATCH v3 06/11] mm, pmem: Implement ->memory_failure() in pmem driver Shiyang Ruan
2021-02-10 13:41 ` Christoph Hellwig
2021-02-08 10:55 ` [PATCH v3 07/11] pmem: Implement ->corrupted_range() for " Shiyang Ruan
2021-02-08 10:55 ` [PATCH v3 08/11] dm: Introduce ->rmap() to find bdev offset Shiyang Ruan
2021-02-08 10:55 ` [PATCH v3 09/11] md: Implement ->corrupted_range() Shiyang Ruan
2021-02-08 10:55 ` [PATCH v3 10/11] xfs: Implement ->corrupted_range() for XFS Shiyang Ruan
2021-02-10 13:44 ` Christoph Hellwig
2021-02-08 10:55 ` [PATCH v3 11/11] fs/dax: Remove useless functions Shiyang Ruan
2021-02-10 13:09 ` Christoph Hellwig
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