f2fs: fix to remove F2FS_COMPR_FL and tag F2FS_NOCOMP_FL at the same time

f2fs: fix to remove F2FS_COMPR_FL and tag F2FS_NOCOMP_FL at the same time

[ Upstream commit 95da85c9638fb3691789755672aa2158ef12a841 ]

If the inode has the compress flag, it will fail to use
'chattr -c +m' to remove its compress flag and tag no compress flag.
However, the same command will be successful when executed again,
as shown below:

  $ touch foo.txt
  $ chattr +c foo.txt
  $ chattr -c +m foo.txt
  chattr: Invalid argument while setting flags on foo.txt
  $ chattr -c +m foo.txt
  $ f2fs_io getflags foo.txt
  get a flag on foo.txt ret=0, flags=nocompression,inline_data

Fix this by removing some checks in f2fs_setflags_common()
that do not affect the original logic. I go through all the
possible scenarios, and the results are as follows. Bold is
the only thing that has changed.

+---------------+-----------+-----------+----------+
|               |            file flags            |
+ command       +-----------+-----------+----------+
|               | no flag   | compr     | nocompr  |
+---------------+-----------+-----------+----------+
| chattr +c     | compr     | compr     | -EINVAL  |
| chattr -c     | no flag   | no flag   | nocompr  |
| chattr +m     | nocompr   | -EINVAL   | nocompr  |
| chattr -m     | no flag   | compr     | no flag  |
| chattr +c +m  | -EINVAL   | -EINVAL   | -EINVAL  |
| chattr +c -m  | compr     | compr     | compr    |
| chattr -c +m  | nocompr   | *nocompr* | nocompr  |
| chattr -c -m  | no flag   | no flag   | no flag  |
+---------------+-----------+-----------+----------+

Link: https://lore.kernel.org/linux-f2fs-devel/20220621064833.1079383-1-chaoliu719@gmail.com/
Fixes: 03a7cb849886 ("f2fs: support data compression")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Chao Liu <liuchao@coolpad.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>