From: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
To: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@gmail.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
kexec@lists.infradead.org, Jan Willeke <willeke@de.ibm.com>,
linux-kernel@vger.kernel.org,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Vivek Goyal <vgoyal@redhat.com>
Subject: Re: [PATCH v5 3/5] vmcore: Introduce remap_oldmem_pfn_range()
Date: Thu, 13 Jun 2013 10:32:48 +0900 [thread overview]
Message-ID: <51B92140.9050407@jp.fujitsu.com> (raw)
In-Reply-To: <20130612111303.3323f24f@holzheu>
(2013/06/12 18:13), Michael Holzheu wrote:
> On Tue, 11 Jun 2013 21:42:15 +0900
> HATAYAMA Daisuke <d.hatayama@gmail.com> wrote:
>
>> 2013/6/11 Michael Holzheu <holzheu@linux.vnet.ibm.com>:
>>> On Mon, 10 Jun 2013 22:40:24 +0900
>>> HATAYAMA Daisuke <d.hatayama@gmail.com> wrote:
>>>
>>>> 2013/6/8 Michael Holzheu <holzheu@linux.vnet.ibm.com>:
<cut>
> static int mmap_vmcore_fault(struct vm_area_struct *vma, struct'vm_fault *vmf)
> {
> struct address_space *mapping = vma->vm_private_data;
> pgoff_t index = vmf->pgoff;
> struct page *page;
> loff_t src;
> char *buf;
>
> page = find_or_create_page(mapping, index, GFP_KERNEL);
> if (!page)
> return VM_FAULT_OOM;
> if (!PageUptodate(page)) {
> src = index << PAGE_CACHE_SHIFT;
> buf = (void *) (page_to_pfn(page) << PAGE_SHIFT);
> if (__read_vmcore(buf, PAGE_SIZE, &src, 0) < 0) {
> unlock_page(page);
> return VM_FAULT_SIGBUS;
> }
> SetPageUptodate(page);
> }
> unlock_page(page);
> vmf->page = page;
> return 0;
> }
>
> Perhaps one open issue remains:
>
> Can we remove the page from the page cache if __read_vmcore() fails?
>
Yes, use page_cache_release() after unlocking the page like:
if (__read_vmcore(buf, PAGE_SIZE, &src, 0) < 0) {
unlock_page(page);
+ page_cache_release(page);
return VM_FAULT_SIGBUS;
}
BTW, you now keep file->f_mapping in vma->vm_private_data, but the vma already has the file object in its vma->vm_file member. You can get the mapping by vma->vm_file->f_mapping without necessity of vma->vm_private_data.
--
Thanks.
HATAYAMA, Daisuke
next prev parent reply other threads:[~2013-06-13 1:33 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-07 16:55 [PATCH v5 0/5] kdump: Allow ELF header creation in new kernel Michael Holzheu
2013-06-07 16:55 ` [PATCH v5 1/5] vmcore: Introduce ELF header in new memory feature Michael Holzheu
2013-06-10 13:35 ` HATAYAMA Daisuke
2013-06-10 13:53 ` Michael Holzheu
2013-06-14 18:54 ` Vivek Goyal
2013-06-21 14:17 ` Michael Holzheu
2013-06-27 19:32 ` Vivek Goyal
2013-06-27 20:10 ` Cliff Wickman
2013-06-27 20:23 ` Vivek Goyal
2013-06-28 8:15 ` Michael Holzheu
2013-07-01 17:37 ` Vivek Goyal
2013-07-01 18:29 ` Michael Holzheu
2013-06-07 16:55 ` [PATCH v5 2/5] s390/vmcore: Use " Michael Holzheu
2013-06-10 13:36 ` HATAYAMA Daisuke
2013-06-10 13:48 ` Michael Holzheu
2013-06-14 19:16 ` Vivek Goyal
2013-06-07 16:55 ` [PATCH v5 3/5] vmcore: Introduce remap_oldmem_pfn_range() Michael Holzheu
[not found] ` <CAJGZr0+_W0dp2f9VtVAiUT2fqiwe91gHXd9zYzfMMzBZSZogww@mail.gmail.com>
2013-06-10 8:00 ` Michael Holzheu
2013-06-10 13:40 ` HATAYAMA Daisuke
2013-06-10 14:03 ` Michael Holzheu
2013-06-10 15:37 ` Michael Holzheu
2013-06-11 12:42 ` HATAYAMA Daisuke
2013-06-12 9:13 ` Michael Holzheu
2013-06-13 1:32 ` HATAYAMA Daisuke [this message]
2013-06-13 8:54 ` Michael Holzheu
2013-06-13 4:00 ` HATAYAMA Daisuke
2013-06-11 13:20 ` HATAYAMA Daisuke
2013-06-07 16:56 ` [PATCH v5 4/5] s390/vmcore: Implement remap_oldmem_pfn_range for s390 Michael Holzheu
2013-06-14 20:08 ` Vivek Goyal
2013-06-07 16:56 ` [PATCH v5 5/5] s390/vmcore: Use vmcore for zfcpdump Michael Holzheu
2013-06-11 23:47 ` HATAYAMA Daisuke
2013-06-12 9:14 ` Michael Holzheu
2013-06-14 18:54 ` [PATCH v5 0/5] kdump: Allow ELF header creation in new kernel Vivek Goyal
2013-06-21 13:39 ` Michael Holzheu
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