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In-Reply-To: <f4a594a1-464f-3a74-90cb-fd536bed9962@huawei.com>
From:   Daeho Jeong <daeho43@gmail.com>
Date:   Wed, 15 Jul 2020 15:54:36 +0900
Message-ID: <CACOAw_w3OWDVXSYHuTEEVv1HaBZir1CWcRAmxOt00MB4vXBKVg@mail.gmail.com>
Subject: Re: [f2fs-dev] [PATCH v2] f2fs: change the way of handling range.len
 in F2FS_IOC_SEC_TRIM_FILE
To:     Chao Yu <yuchao0@huawei.com>
Cc:     Jaegeuk Kim <jaegeuk@kernel.org>,
        Daeho Jeong <daehojeong@google.com>, kernel-team@android.com,
        linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net
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You mean we can support ZEROOUT option only for encrypted files of
non-multidevice f2fs,
and return -EOPNOTSUPP in the multidevice case, right now?

2020=EB=85=84 7=EC=9B=94 15=EC=9D=BC (=EC=88=98) =EC=98=A4=ED=9B=84 3:17, C=
hao Yu <yuchao0@huawei.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
>
> On 2020/7/15 12:06, Daeho Jeong wrote:
> > We could use fscrypt_zeroout_range() for an encrypted file.
> > But, one problem is fscrypt_zeroout_range() assumes that filesystems
> > only use a single block device.
> > It means it doesn't receive bdev as a parameter.
> > How about changing the interface of fscrypt_zeroout_range() first and u=
sing it?
>
> Yes, please limited to use fscrypt_zeroout_range() on non-multidevice f2f=
s image
> first, we can add a condition to check that in the beginning of ioctl int=
erface,
> once fscrypt_zeroout_range() accepts bdev as parameter, we can remove tha=
t limitation.
>
> Thanks,
>
> >
> > 2020=EB=85=84 7=EC=9B=94 14=EC=9D=BC (=ED=99=94) =EC=98=A4=ED=9B=84 9:3=
6, Chao Yu <yuchao0@huawei.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
> >>
> >> On 2020/7/14 2:11, Jaegeuk Kim wrote:
> >>> Hi Daeho,
> >>>
> >>> Please take a look at this.
> >>>
> >>> https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/comm=
it/?h=3Ddev&id=3D35245180459aebf6d70fde88a538f0400a794aa6
> >>
> >> I'm curious about what will happen if we call
> >> sec_trim_file(F2FS_TRIM_FILE_ZEROOUT) on an encrypted file, will
> >> it use zero bits covering encrypted data on disk?
> >>
> >> Thanks,
> >>
> >>>
> >>> Thanks,
> >>>
> >>> On 07/13, Daeho Jeong wrote:
> >>>> From: Daeho Jeong <daehojeong@google.com>
> >>>>
> >>>> Changed the way of handling range.len of F2FS_IOC_SEC_TRIM_FILE.
> >>>>  1. Added -1 value support for range.len to secure trim the whole bl=
ocks
> >>>>     starting from range.start regardless of i_size.
> >>>>  2. If the end of the range passes over the end of file, it means un=
til
> >>>>     the end of file (i_size).
> >>>>  3. ignored the case of that range.len is zero to prevent the functi=
on
> >>>>     from making end_addr zero and triggering different behaviour of
> >>>>     the function.
> >>>>
> >>>> Signed-off-by: Daeho Jeong <daehojeong@google.com>
> >>>> ---
> >>>> Changes in v2:
> >>>>  - Changed -1 range.len option to mean the whole blocks starting fro=
m
> >>>>    range.start regardless of i_size
> >>>> ---
> >>>>  fs/f2fs/file.c | 23 ++++++++++++-----------
> >>>>  1 file changed, 12 insertions(+), 11 deletions(-)
> >>>>
> >>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> >>>> index 368c80f8e2a1..2485841e3b2d 100644
> >>>> --- a/fs/f2fs/file.c
> >>>> +++ b/fs/f2fs/file.c
> >>>> @@ -3792,7 +3792,7 @@ static int f2fs_sec_trim_file(struct file *fil=
p, unsigned long arg)
> >>>>      pgoff_t index, pg_end;
> >>>>      block_t prev_block =3D 0, len =3D 0;
> >>>>      loff_t end_addr;
> >>>> -    bool to_end;
> >>>> +    bool to_end =3D false;
> >>>>      int ret =3D 0;
> >>>>
> >>>>      if (!(filp->f_mode & FMODE_WRITE))
> >>>> @@ -3813,23 +3813,23 @@ static int f2fs_sec_trim_file(struct file *f=
ilp, unsigned long arg)
> >>>>      file_start_write(filp);
> >>>>      inode_lock(inode);
> >>>>
> >>>> -    if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode)) =
{
> >>>> +    if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode) |=
|
> >>>> +                    range.start >=3D inode->i_size) {
> >>>>              ret =3D -EINVAL;
> >>>>              goto err;
> >>>>      }
> >>>>
> >>>> -    if (range.start >=3D inode->i_size) {
> >>>> -            ret =3D -EINVAL;
> >>>> +    if (range.len =3D=3D 0)
> >>>>              goto err;
> >>>> -    }
> >>>>
> >>>> -    if (inode->i_size - range.start < range.len) {
> >>>> -            ret =3D -E2BIG;
> >>>> -            goto err;
> >>>> +    if (inode->i_size - range.start > range.len) {
> >>>> +            end_addr =3D range.start + range.len;
> >>>> +    } else {
> >>>> +            end_addr =3D range.len =3D=3D (u64)-1 ?
> >>>> +                    sbi->sb->s_maxbytes : inode->i_size;
> >>>> +            to_end =3D true;
> >>>>      }
> >>>> -    end_addr =3D range.start + range.len;
> >>>>
> >>>> -    to_end =3D (end_addr =3D=3D inode->i_size);
> >>>>      if (!IS_ALIGNED(range.start, F2FS_BLKSIZE) ||
> >>>>                      (!to_end && !IS_ALIGNED(end_addr, F2FS_BLKSIZE)=
)) {
> >>>>              ret =3D -EINVAL;
> >>>> @@ -3846,7 +3846,8 @@ static int f2fs_sec_trim_file(struct file *fil=
p, unsigned long arg)
> >>>>      down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
> >>>>      down_write(&F2FS_I(inode)->i_mmap_sem);
> >>>>
> >>>> -    ret =3D filemap_write_and_wait_range(mapping, range.start, end_=
addr - 1);
> >>>> +    ret =3D filemap_write_and_wait_range(mapping, range.start,
> >>>> +                    to_end ? LLONG_MAX : end_addr - 1);
> >>>>      if (ret)
> >>>>              goto out;
> >>>>
> >>>> --
> >>>> 2.27.0.383.g050319c2ae-goog
> >>>
> >>>
> >>> _______________________________________________
> >>> Linux-f2fs-devel mailing list
> >>> Linux-f2fs-devel@lists.sourceforge.net
> >>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> >>> .
> >>>
> > .
> >