Re: [PATCH v2 08/10] ext4: factor out ext4_do_fallocate()

[Jan Kara <jack@suse.cz>]

On Wed 04-09-24 14:29:23, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
> 
> Now the real job of normal fallocate are open code in ext4_fallocate(),
> factor out a new helper ext4_do_fallocate() to do the real job, like
> others functions (e.g. ext4_zero_range()) in ext4_fallocate() do, this
> can make the code more clear, no functional changes.
> 
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/extents.c | 125 ++++++++++++++++++++++------------------------
>  1 file changed, 60 insertions(+), 65 deletions(-)
> 
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index a6c24c229cb4..06b2c1190181 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -4662,6 +4662,58 @@ static long ext4_zero_range(struct file *file, loff_t offset,
>  	return ret;
>  }
>  
> +static long ext4_do_fallocate(struct file *file, loff_t offset,
> +			      loff_t len, int mode)
> +{
> +	struct inode *inode = file_inode(file);
> +	loff_t end = offset + len;
> +	loff_t new_size = 0;
> +	ext4_lblk_t start_lblk, len_lblk;
> +	int ret;
> +
> +	trace_ext4_fallocate_enter(inode, offset, len, mode);
> +
> +	start_lblk = offset >> inode->i_blkbits;
> +	len_lblk = EXT4_MAX_BLOCKS(len, offset, inode->i_blkbits);
> +
> +	inode_lock(inode);
> +
> +	/* We only support preallocation for extent-based files only. */
> +	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
> +		ret = -EOPNOTSUPP;
> +		goto out;
> +	}
> +
> +	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
> +	    (end > inode->i_size || end > EXT4_I(inode)->i_disksize)) {
> +		new_size = end;
> +		ret = inode_newsize_ok(inode, new_size);
> +		if (ret)
> +			goto out;
> +	}
> +
> +	/* Wait all existing dio workers, newcomers will block on i_rwsem */
> +	inode_dio_wait(inode);
> +
> +	ret = file_modified(file);
> +	if (ret)
> +		goto out;
> +
> +	ret = ext4_alloc_file_blocks(file, start_lblk, len_lblk, new_size,
> +				     EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT);
> +	if (ret)
> +		goto out;
> +
> +	if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
> +		ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal,
> +					EXT4_I(inode)->i_sync_tid);
> +	}
> +out:
> +	inode_unlock(inode);
> +	trace_ext4_fallocate_exit(inode, offset, len_lblk, ret);
> +	return ret;
> +}
> +
>  /*
>   * preallocate space for a file. This implements ext4's fallocate file
>   * operation, which gets called from sys_fallocate system call.
> @@ -4672,12 +4724,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
>  long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
>  {
>  	struct inode *inode = file_inode(file);
> -	loff_t new_size = 0;
> -	unsigned int max_blocks;
> -	int ret = 0;
> -	int flags;
> -	ext4_lblk_t lblk;
> -	unsigned int blkbits = inode->i_blkbits;
> +	int ret;
>  
>  	/*
>  	 * Encrypted inodes can't handle collapse range or insert
> @@ -4699,71 +4746,19 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
>  	ret = ext4_convert_inline_data(inode);
>  	inode_unlock(inode);
>  	if (ret)
> -		goto exit;
> +		return ret;
>  
> -	if (mode & FALLOC_FL_PUNCH_HOLE) {
> +	if (mode & FALLOC_FL_PUNCH_HOLE)
>  		ret = ext4_punch_hole(file, offset, len);
> -		goto exit;
> -	}
> -
> -	if (mode & FALLOC_FL_COLLAPSE_RANGE) {
> +	else if (mode & FALLOC_FL_COLLAPSE_RANGE)
>  		ret = ext4_collapse_range(file, offset, len);
> -		goto exit;
> -	}
> -
> -	if (mode & FALLOC_FL_INSERT_RANGE) {
> +	else if (mode & FALLOC_FL_INSERT_RANGE)
>  		ret = ext4_insert_range(file, offset, len);
> -		goto exit;
> -	}
> -
> -	if (mode & FALLOC_FL_ZERO_RANGE) {
> +	else if (mode & FALLOC_FL_ZERO_RANGE)
>  		ret = ext4_zero_range(file, offset, len, mode);
> -		goto exit;
> -	}
> -	trace_ext4_fallocate_enter(inode, offset, len, mode);
> -	lblk = offset >> blkbits;
> -
> -	max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
> -	flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
> -
> -	inode_lock(inode);
> -
> -	/*
> -	 * We only support preallocation for extent-based files only
> -	 */
> -	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
> -		ret = -EOPNOTSUPP;
> -		goto out;
> -	}
> -
> -	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
> -	    (offset + len > inode->i_size ||
> -	     offset + len > EXT4_I(inode)->i_disksize)) {
> -		new_size = offset + len;
> -		ret = inode_newsize_ok(inode, new_size);
> -		if (ret)
> -			goto out;
> -	}
> -
> -	/* Wait all existing dio workers, newcomers will block on i_rwsem */
> -	inode_dio_wait(inode);
> -
> -	ret = file_modified(file);
> -	if (ret)
> -		goto out;
> -
> -	ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags);
> -	if (ret)
> -		goto out;
> +	else
> +		ret = ext4_do_fallocate(file, offset, len, mode);
>  
> -	if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
> -		ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal,
> -					EXT4_I(inode)->i_sync_tid);
> -	}
> -out:
> -	inode_unlock(inode);
> -	trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
> -exit:
>  	return ret;
>  }
>  
> -- 
> 2.39.2
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR