Received-SPF: pass (google.com: best guess record for domain of linux-ext4-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCHv3 1/6] ext4: Add IOMAP_F_MERGED for non-extent based
 mapping
To:     Jan Kara <jack@suse.cz>
Cc:     tytso@mit.edu, linux-ext4@vger.kernel.org,
        adilger.kernel@dilger.ca, linux-fsdevel@vger.kernel.org,
        darrick.wong@oracle.com, hch@infradead.org, cmaiolino@redhat.com
References: <cover.1582702693.git.riteshh@linux.ibm.com>
 <25695b1a4bc3b5c3a2f513ecb612195aa7154975.1582702693.git.riteshh@linux.ibm.com>
 <20200226122655.GM10728@quack2.suse.cz>
From:   Ritesh Harjani <riteshh@linux.ibm.com>
Date:   Wed, 26 Feb 2020 18:03:57 +0530
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.7.2
MIME-Version: 1.0
In-Reply-To: <20200226122655.GM10728@quack2.suse.cz>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Message-Id: <20200226123358.60F425204E@d06av21.portsmouth.uk.ibm.com>
Sender: linux-ext4-owner@vger.kernel.org
Precedence: bulk


On 2/26/20 5:56 PM, Jan Kara wrote:
> On Wed 26-02-20 15:27:03, Ritesh Harjani wrote:
>> IOMAP_F_MERGED needs to be set in case of non-extent based mapping.
>> This is needed in later patches for conversion of ext4_fiemap to use iomap.
>>
>> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
>> ---
>>   fs/ext4/inode.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
>> index d035acab5b2a..3b4230cf0bc2 100644
>> --- a/fs/ext4/inode.c
>> +++ b/fs/ext4/inode.c
>> @@ -3335,6 +3335,10 @@ static void ext4_set_iomap(struct inode *inode, struct iomap *iomap,
>>   	iomap->offset = (u64) map->m_lblk << blkbits;
>>   	iomap->length = (u64) map->m_len << blkbits;
>>   
>> +	if ((map->m_flags & (EXT4_MAP_UNWRITTEN | EXT4_MAP_MAPPED)) &&
>> +		!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
>     ^^ we indent the second line of condition either like:
> 
> 	if ((map->m_flags & (EXT4_MAP_UNWRITTEN | EXT4_MAP_MAPPED)) &&
> 	    !ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))

Yes, I too prefer it this way. Will fix it.

> 
> or like:
> 
> 	if ((map->m_flags & (EXT4_MAP_UNWRITTEN | EXT4_MAP_MAPPED)) &&
> 			!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
> 
> But on at the same level as following code block because that's highly
> confusing at times...
> 
> Also EXT4_MAP_UNWRITTEN is never set for indirect block mapped files (that
> on disk format does not support unwritten extents).

Aah yes. Let me fix it.

> 
> 								Honza
> 
>> +		iomap->flags |= IOMAP_F_MERGED;
>> +
>>   	/*
>>   	 * Flags passed to ext4_map_blocks() for direct I/O writes can result
>>   	 * in m_flags having both EXT4_MAP_MAPPED and EXT4_MAP_UNWRITTEN bits
>> -- 
>> 2.21.0
>>