Subject: Re: [PATCH v2 1/2] ext4: introduce 'update_only' parameter for
 ext4_find_inline_data_nolock()
To:     Jan Kara <jack@suse.cz>, Ye Bin <yebin@huaweicloud.com>
References: <20230303082158.4012809-1-yebin@huaweicloud.com>
 <20230303082158.4012809-2-yebin@huaweicloud.com>
 <20230303095536.7h7hlpf5v54tjpbj@quack3>
CC:     <tytso@mit.edu>, <adilger.kernel@dilger.ca>,
        <linux-ext4@vger.kernel.org>, <linux-kernel@vger.kernel.org>
From:   "yebin (H)" <yebin10@huawei.com>
Message-ID: <64029BE6.6060003@huawei.com>
Date:   Sat, 4 Mar 2023 09:16:22 +0800
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On 2023/3/3 17:55, Jan Kara wrote:
> On Fri 03-03-23 16:21:57, Ye Bin wrote:
>> From: Ye Bin <yebin10@huawei.com>
>>
>> Introduce 'update_only' parameter for ext4_find_inline_data_nolock() to
>> use this function to update 'inline_off' only.
>>
>> Signed-off-by: Ye Bin <yebin10@huawei.com>
> Now looking at the patch maybe we could do better? The call in
> ext4_write_inline_data_end() is there also only to update i_inline_off and
> setting EXT4_STATE_MAY_INLINE_DATA from that call is not strictly
> problematic (we are just writing new inline data so we cannot be converting
> them) but not necessary either. So maybe we should instead move setting of
> EXT4_STATE_MAY_INLINE_DATA into ext4_iget_extra_inode() and remove it from
> ext4_find_inline_data_nolock()? Then we won't need the 'update_only'
> argument...
>
> 								Honza
Thank you for your suggestion. It really seems to be a good idea. I will 
send new patches.
>> ---
>>   fs/ext4/ext4.h   | 2 +-
>>   fs/ext4/inline.c | 7 ++++---
>>   fs/ext4/inode.c  | 2 +-
>>   3 files changed, 6 insertions(+), 5 deletions(-)
>>
>> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
>> index 4eeb02d456a9..b073976f4bf2 100644
>> --- a/fs/ext4/ext4.h
>> +++ b/fs/ext4/ext4.h
>> @@ -3545,7 +3545,7 @@ extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
>>   
>>   /* inline.c */
>>   extern int ext4_get_max_inline_size(struct inode *inode);
>> -extern int ext4_find_inline_data_nolock(struct inode *inode);
>> +extern int ext4_find_inline_data_nolock(struct inode *inode, bool update_only);
>>   extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
>>   				 unsigned int len);
>>   extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
>> diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
>> index 2b42ececa46d..0fa8f41de3de 100644
>> --- a/fs/ext4/inline.c
>> +++ b/fs/ext4/inline.c
>> @@ -126,7 +126,7 @@ int ext4_get_max_inline_size(struct inode *inode)
>>    * currently only used in a code path coming form ext4_iget, before
>>    * the new inode has been unlocked
>>    */
>> -int ext4_find_inline_data_nolock(struct inode *inode)
>> +int ext4_find_inline_data_nolock(struct inode *inode, bool update_only)
>>   {
>>   	struct ext4_xattr_ibody_find is = {
>>   		.s = { .not_found = -ENODATA, },
>> @@ -159,7 +159,8 @@ int ext4_find_inline_data_nolock(struct inode *inode)
>>   					(void *)ext4_raw_inode(&is.iloc));
>>   		EXT4_I(inode)->i_inline_size = EXT4_MIN_INLINE_DATA_SIZE +
>>   				le32_to_cpu(is.s.here->e_value_size);
>> -		ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
>> +		if (!update_only)
>> +			ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
>>   	}
>>   out:
>>   	brelse(is.iloc.bh);
>> @@ -761,7 +762,7 @@ int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
>>   		 * ext4_write_begin() called
>>   		 * ext4_try_to_write_inline_data()
>>   		 */
>> -		(void) ext4_find_inline_data_nolock(inode);
>> +		(void) ext4_find_inline_data_nolock(inode, false);
>>   
>>   		kaddr = kmap_atomic(page);
>>   		ext4_write_inline_data(inode, &iloc, kaddr, pos, copied);
>> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
>> index d251d705c276..6ecaa1bef9bb 100644
>> --- a/fs/ext4/inode.c
>> +++ b/fs/ext4/inode.c
>> @@ -4798,7 +4798,7 @@ static inline int ext4_iget_extra_inode(struct inode *inode,
>>   	if (EXT4_INODE_HAS_XATTR_SPACE(inode)  &&
>>   	    *magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
>>   		ext4_set_inode_state(inode, EXT4_STATE_XATTR);
>> -		return ext4_find_inline_data_nolock(inode);
>> +		return ext4_find_inline_data_nolock(inode, false);
>>   	} else
>>   		EXT4_I(inode)->i_inline_off = 0;
>>   	return 0;
>> -- 
>> 2.31.1
>>