lkml.org 
[lkml]   [2018]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] jffs2: safely remove obsolete dirent from the f->dents list
From
Date

On 2018/4/28 6:22, David Woodhouse wrote:
> This looks a lot better than the first iteration; thank you for getting
> it to this point. One last thing, I hope...
> On Thu, 2018-03-29 at 20:00 +0800, Yufen Yu wrote:
>> --- a/fs/jffs2/jffs2_fs_i.h
>> +++ b/fs/jffs2/jffs2_fs_i.h
>> @@ -42,6 +42,12 @@ struct jffs2_inode_info {
>> /* Directory entries */
>> struct jffs2_full_dirent *dents;
>>
>> + /* Directory open refcount */
>> + atomic_t nr_dir_opening;
>> +
>> + /* obsolete dirent count in the list of 'dents' */
>> + unsigned int obsolete_count;
>> +
>> /* The target path if this is the inode of a symlink */
>> unsigned char *target;
>>
> You've made JFFS2_INVALID_LIMIT 64, which is reasonable enough
> (although it's a bit of a weird name and possibly wants to be more
> specific — invalid *what*?).
Thansk a lot for your suggestions.

Yes, it is really a bad name. How about JFFS2_OBS_DIRENT_LIMIT? I am
not sure.

>
> So the maximum interesting value of ->obsolete_count is 64. Which means
> it might as well be a uint8_t and sit in the padding after the
> 'usercompr' field.
>
> It might be useful to look at putting the mutually exclusive fields in
> struct jffs2_inode_info into a union, and then we don't need the
> additional space of the atomic_t either; we'll never need that *and*
> the fragtree at the same time... will we?
You are right, thanks. But, obsolete_count may be large. So, I apply to
use uint16_t and
it also sits in the padding after the 'usercompr' field.

Thanks,
Yufen

\
 
 \ /
  Last update: 2018-05-04 10:07    [W:0.105 / U:0.560 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site