Re: [PATCH] f2fs: fix to remove F2FS_COMPR_FL and tag F2FS_NOCOMP_FL at the same time

From: Chao Yu
Date: Wed Jul 06 2022 - 10:21:17 EST


On 2022/6/21 14:48, Chao Liu wrote:
From: Chao Liu <liuchao@xxxxxxxxxxx>

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 |
+---------------+-----------+-----------+----------+

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Liu <liuchao@xxxxxxxxxxx>

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,