Re: [PATCH 09/27] ext4: move out inode_lock into ext4_fallocate()

[Jan Kara <jack@suse.cz>]

On Tue 22-10-24 19:10:40, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
> 
> Currently, all five sub-functions of ext4_fallocate() acquire the
> inode's i_rwsem at the beginning and release it before exiting. This
> process can be simplified by factoring out the management of i_rwsem
> into the ext4_fallocate() function.
> 
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

Ah, nice. Feel free to add:

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

and please ignore my comments about renaming 'out' labels :).

								Honza

> ---
>  fs/ext4/extents.c | 90 +++++++++++++++--------------------------------
>  fs/ext4/inode.c   | 13 +++----
>  2 files changed, 33 insertions(+), 70 deletions(-)
> 
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 2f727104f53d..a2db4e85790f 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -4573,23 +4573,18 @@ static long ext4_zero_range(struct file *file, loff_t offset,
>  	int ret, flags, credits;
>  
>  	trace_ext4_zero_range(inode, offset, len, mode);
> +	WARN_ON_ONCE(!inode_is_locked(inode));
>  
> -	inode_lock(inode);
> -
> -	/*
> -	 * Indirect files do not support unwritten extents
> -	 */
> -	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
> -		ret = -EOPNOTSUPP;
> -		goto out;
> -	}
> +	/* Indirect files do not support unwritten extents */
> +	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
> +		return -EOPNOTSUPP;
>  
>  	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;
> +			return ret;
>  	}
>  
>  	/* Wait all existing dio workers, newcomers will block on i_rwsem */
> @@ -4597,7 +4592,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
>  
>  	ret = file_modified(file);
>  	if (ret)
> -		goto out;
> +		return ret;
>  
>  	/*
>  	 * Prevent page faults from reinstantiating pages we have released
> @@ -4687,8 +4682,6 @@ static long ext4_zero_range(struct file *file, loff_t offset,
>  	ext4_journal_stop(handle);
>  out_invalidate_lock:
>  	filemap_invalidate_unlock(mapping);
> -out:
> -	inode_unlock(inode);
>  	return ret;
>  }
>  
> @@ -4702,12 +4695,11 @@ static long ext4_do_fallocate(struct file *file, loff_t offset,
>  	int ret;
>  
>  	trace_ext4_fallocate_enter(inode, offset, len, mode);
> +	WARN_ON_ONCE(!inode_is_locked(inode));
>  
>  	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;
> @@ -4739,7 +4731,6 @@ static long ext4_do_fallocate(struct file *file, loff_t offset,
>  					EXT4_I(inode)->i_sync_tid);
>  	}
>  out:
> -	inode_unlock(inode);
>  	trace_ext4_fallocate_exit(inode, offset, len_lblk, ret);
>  	return ret;
>  }
> @@ -4774,9 +4765,8 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
>  
>  	inode_lock(inode);
>  	ret = ext4_convert_inline_data(inode);
> -	inode_unlock(inode);
>  	if (ret)
> -		return ret;
> +		goto out;
>  
>  	if (mode & FALLOC_FL_PUNCH_HOLE)
>  		ret = ext4_punch_hole(file, offset, len);
> @@ -4788,7 +4778,8 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
>  		ret = ext4_zero_range(file, offset, len, mode);
>  	else
>  		ret = ext4_do_fallocate(file, offset, len, mode);
> -
> +out:
> +	inode_unlock(inode);
>  	return ret;
>  }
>  
> @@ -5298,36 +5289,27 @@ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
>  	int ret;
>  
>  	trace_ext4_collapse_range(inode, offset, len);
> -
> -	inode_lock(inode);
> +	WARN_ON_ONCE(!inode_is_locked(inode));
>  
>  	/* Currently just for extent based files */
> -	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
> -		ret = -EOPNOTSUPP;
> -		goto out;
> -	}
> -
> +	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
> +		return -EOPNOTSUPP;
>  	/* Collapse range works only on fs cluster size aligned regions. */
> -	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) {
> -		ret = -EINVAL;
> -		goto out;
> -	}
> -
> +	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
> +		return -EINVAL;
>  	/*
>  	 * There is no need to overlap collapse range with EOF, in which case
>  	 * it is effectively a truncate operation
>  	 */
> -	if (end >= inode->i_size) {
> -		ret = -EINVAL;
> -		goto out;
> -	}
> +	if (end >= inode->i_size)
> +		return -EINVAL;
>  
>  	/* Wait for existing dio to complete */
>  	inode_dio_wait(inode);
>  
>  	ret = file_modified(file);
>  	if (ret)
> -		goto out;
> +		return ret;
>  
>  	/*
>  	 * Prevent page faults from reinstantiating pages we have released from
> @@ -5402,8 +5384,6 @@ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
>  	ext4_journal_stop(handle);
>  out_invalidate_lock:
>  	filemap_invalidate_unlock(mapping);
> -out:
> -	inode_unlock(inode);
>  	return ret;
>  }
>  
> @@ -5429,39 +5409,27 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
>  	loff_t start;
>  
>  	trace_ext4_insert_range(inode, offset, len);
> -
> -	inode_lock(inode);
> +	WARN_ON_ONCE(!inode_is_locked(inode));
>  
>  	/* Currently just for extent based files */
> -	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
> -		ret = -EOPNOTSUPP;
> -		goto out;
> -	}
> -
> +	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
> +		return -EOPNOTSUPP;
>  	/* Insert range works only on fs cluster size aligned regions. */
> -	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) {
> -		ret = -EINVAL;
> -		goto out;
> -	}
> -
> +	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
> +		return -EINVAL;
>  	/* Offset must be less than i_size */
> -	if (offset >= inode->i_size) {
> -		ret = -EINVAL;
> -		goto out;
> -	}
> -
> +	if (offset >= inode->i_size)
> +		return -EINVAL;
>  	/* Check whether the maximum file size would be exceeded */
> -	if (len > inode->i_sb->s_maxbytes - inode->i_size) {
> -		ret = -EFBIG;
> -		goto out;
> -	}
> +	if (len > inode->i_sb->s_maxbytes - inode->i_size)
> +		return -EFBIG;
>  
>  	/* Wait for existing dio to complete */
>  	inode_dio_wait(inode);
>  
>  	ret = file_modified(file);
>  	if (ret)
> -		goto out;
> +		return ret;
>  
>  	/*
>  	 * Prevent page faults from reinstantiating pages we have released from
> @@ -5562,8 +5530,6 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
>  	ext4_journal_stop(handle);
>  out_invalidate_lock:
>  	filemap_invalidate_unlock(mapping);
> -out:
> -	inode_unlock(inode);
>  	return ret;
>  }
>  
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 1d128333bd06..bea19cd6e676 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -3962,15 +3962,14 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
>  	unsigned long blocksize = i_blocksize(inode);
>  	handle_t *handle;
>  	unsigned int credits;
> -	int ret = 0;
> +	int ret;
>  
>  	trace_ext4_punch_hole(inode, offset, length, 0);
> -
> -	inode_lock(inode);
> +	WARN_ON_ONCE(!inode_is_locked(inode));
>  
>  	/* No need to punch hole beyond i_size */
>  	if (offset >= inode->i_size)
> -		goto out;
> +		return 0;
>  
>  	/*
>  	 * If the hole extends beyond i_size, set the hole to end after
> @@ -3990,7 +3989,7 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
>  	if (offset & (blocksize - 1) || end & (blocksize - 1)) {
>  		ret = ext4_inode_attach_jinode(inode);
>  		if (ret < 0)
> -			goto out;
> +			return ret;
>  	}
>  
>  	/* Wait all existing dio workers, newcomers will block on i_rwsem */
> @@ -3998,7 +3997,7 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
>  
>  	ret = file_modified(file);
>  	if (ret)
> -		goto out;
> +		return ret;
>  
>  	/*
>  	 * Prevent page faults from reinstantiating pages we have released from
> @@ -4082,8 +4081,6 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
>  	ext4_journal_stop(handle);
>  out_invalidate_lock:
>  	filemap_invalidate_unlock(mapping);
> -out:
> -	inode_unlock(inode);
>  	return ret;
>  }
>  
> -- 
> 2.46.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR