"Darrick J. Wong" <djwong@xxxxxxxxxx> writes:
> On Fri, Oct 25, 2024 at 04:03:02PM +0530, Ritesh Harjani wrote:
>> John Garry <john.g.garry@xxxxxxxxxx> writes:
>>
>> > On 25/10/2024 04:45, Ritesh Harjani (IBM) wrote:
>> >> Let's validate using generic_atomic_write_valid() in
>> >> ext4_file_write_iter() if the write request has IOCB_ATOMIC set.
>> >>
>> >> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
>> >> ---
>> >> fs/ext4/file.c | 14 ++++++++++++++
>> >> 1 file changed, 14 insertions(+)
>> >>
>> >> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
>> >> index f14aed14b9cf..b06c5d34bbd2 100644
>> >> --- a/fs/ext4/file.c
>> >> +++ b/fs/ext4/file.c
>> >> @@ -692,6 +692,20 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
>> >> if (IS_DAX(inode))
>> >> return ext4_dax_write_iter(iocb, from);
>> >> #endif
>> >> +
>> >> + if (iocb->ki_flags & IOCB_ATOMIC) {
>> >> + size_t len = iov_iter_count(from);
>> >> + int ret;
>> >> +
>> >> + if (!IS_ALIGNED(len, EXT4_SB(inode->i_sb)->fs_awu_min) ||
>> >> + len > EXT4_SB(inode->i_sb)->fs_awu_max)
>> >> + return -EINVAL;
>> >
>> > this looks ok, but the IS_ALIGNED() check looks odd. I am not sure why
>> > you don't just check that fs_awu_max >= len >= fs_awu_min
>> >
>>
>> I guess this was just a stricter check. But we anyways have power_of_2
>> and other checks in generic_atomic_write_valid(). So it does not matter.
>>
>> I can change this in v2.
>
> Also please fix the weird indenting in the if test:
>
> if (len < EXT4_SB(inode->i_sb)->fs_awu_min) ||
> len > EXT4_SB(inode->i_sb)->fs_awu_max)
> return -EINVAL;
>
> --D
Got it!
-ritesh
>
>> Thanks!
>>
>> >> +
>> >> + ret = generic_atomic_write_valid(iocb, from);
>> >> + if (ret)
>> >> + return ret;
>> >> + }
>> >> +
>> >> if (iocb->ki_flags & IOCB_DIRECT)
>> >> return ext4_dio_write_iter(iocb, from);
>> >> else
>>
>> -ritesh
>>
