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.
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
