Re: [PATCH v2 0/4] make '%pD' print the full path of file

On Wed, Jun 23, 2021 at 01:50:07PM +0800, Jia He wrote:

Background
==========
Linus suggested printing the full path of file instead of printing
the components as '%pd'.

Typically, there is no need for printk specifiers to take any real locks
(ie mount_lock or rename_lock). So I introduce a new helper
d_path_unsafe() which is similar to d_path() except it doesn't take any
seqlock/spinlock.

This series is based on Al Viro's d_path() cleanup patches [1] which
lifted the inner lockless loop into a new helper. 

Test
====
The cases I tested:
1. print '%pD' with full path of ext4 file
2. mount a ext4 filesystem upon a ext4 filesystem, and print the file
   with '%pD'
3. all test_print selftests, including the new '%14pD' '%-14pD'
4. kasprintf

TODO
====
I plan to do the followup work after '%pD' behavior is changed.
- s390/hmcdrv: remove the redundant directory path in printing string.
- fs/iomap: simplify the iomap_swapfile_fail() with '%pD'.
- simplify the string printing when file_path() is invoked(in some
  cases, not all).
- change the previous '%pD[2,3,4]' to '%pD'
   
Changelog
=========
v2:

Should be v6 now. So, next v7, otherwise you confuse bots and people.

My remark was for you for the future submission, this one is already spoiled.

- refine the commit msg/comments (Andy)
- pass the validator check by "make C=1 W=1"
- add the R-b for patch 4/4 from Andy

-- 
With Best Regards,
Andy Shevchenko