答复: ext4 error

[Eric Shang]

Hi Toshi:
	Thanks! I think this not relate to DAX and dax_get_unmapped_area, I am a junior kernel maintainer for our company. This issue bother me long time, looks like kernel ext4 issue or our emmc driver issue, I will dig it out, Thanks!

Best Regards
EricShang


-----邮件原件-----
发件人: Toshi Kani [mailto:toshi.kani at hpe.com] 
发送时间: 2016年4月13日 22:10
收件人: Eric Shang; Matthew Wilcox
抄送: akpm at linux-foundation.org; dan.j.williams at intel.com; viro at zeniv.linux.org.uk; ross.zwisler at linux.intel.com; kirill.shutemov at linux.intel.com; david at fromorbit.com; jack at suse.cz; tytso at mit.edu; adilger.kernel at dilger.ca; linux-nvdimm at lists.01.org; linux-fsdevel at vger.kernel.org; linux-ext4 at vger.kernel.org; xfs at oss.sgi.com; linux-kernel at vger.kernel.org
主题: Re: ext4 error

On Wed, 2016-04-13 at 13:44 +0000, Eric Shang wrote:
> HI All:
>   I meet an ext4 error, following is the error log. After panic, I 
> check the emmc by the tool debufs, the inode 69878 i_nlink is not 
> zero. And this inode don't belong to parent dir 6987, it belong to 
> other file(this inode belong to two files when check by debugfs 
> ncheck), I guess than this inode has beed deleted in memory and 
> already used by other file. But the parent dentry buff_head not flush 
> to emmc. But when lookup this dentry can't find it' in dentry cache, 
> and then lookup_real, read the dentry from emmc, get the file inode which already be deleted.
>   Can any give me some help how to check this issue. My kernel version 
> is 3.18 form Android . I thinks something wrong with dentry cache 
> flush and dirty buff_head flush to emmc. Thanks all!

Are you somehow using DAX and my dax_get_unmapped_area patches in your Android
3.18 kernel? I doubt this is the case, but I thought I should check since you reported it to me and Matthew with the same cc list.

If you are simply using a distributed Android kernel, you should report it to Android email list or bug tracker.

-Toshi