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

From: Chao Yu
Date: Wed Jun 22 2022 - 09:42:34 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>
---

This patch depends on the the patch
"f2fs: allow compression of files without blocks" sent earlier this day.

fs/f2fs/file.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index daaa0dfd2d2e..0c3ae5993b7a 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1873,10 +1873,7 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
if (masked_flags & F2FS_COMPR_FL) {
if (!f2fs_disable_compressed_file(inode))
return -EINVAL;
- }
- if (iflags & F2FS_NOCOMP_FL)
- return -EINVAL;
- if (iflags & F2FS_COMPR_FL) {
+ } else {
if (!f2fs_may_compress(inode))
return -EINVAL;
if (S_ISREG(inode->i_mode) && F2FS_HAS_BLOCKS(inode))
@@ -1885,10 +1882,6 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
set_compress_context(inode);
}
}
- if ((iflags ^ masked_flags) & F2FS_NOCOMP_FL) {
- if (masked_flags & F2FS_COMPR_FL)
- return -EINVAL;
- }

Without above check condition, can we return -EINVAL for the case:

chattr +c on file w/ nocompr flag

| | no flag | compr | nocompr |
+---------------+-----------+-----------+----------+
| chattr +c | compr | compr | *-EINVAL* |

Thanks,


fi->i_flags = iflags | (fi->i_flags & ~mask);
f2fs_bug_on(F2FS_I_SB(inode), (fi->i_flags & F2FS_COMPR_FL) &&
--
2.36.1