Commit 49425504 authored by Zhang Yi's avatar Zhang Yi Committed by Theodore Ts'o
Browse files

ext4: refactor ext4_insert_range() 



Simplify ext4_insert_range() and align its code style with that of
ext4_collapse_range(). Refactor it by: a) renaming variables, b)
removing redundant input parameter checks and moving the remaining
checks under i_rwsem in preparation for future refactoring, and c)
renaming the three stale error tags.

Signed-off-by: default avatarZhang Yi <yi.zhang@huawei.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarOjaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-8-yi.zhang@huaweicloud.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 162e3c5a

fs/ext4/extents.c

+48 −53
Original line number Diff line number Diff line
@@ -5425,45 +5425,37 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) 
	handle_t *handle;

	struct ext4_ext_path *path;

	struct ext4_extent *extent;

	ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;

	ext4_lblk_t start_lblk, len_lblk, ee_start_lblk = 0;

	unsigned int credits, ee_len;

	int ret = 0, depth, split_flag = 0;

	loff_t ioffset;



	/*

	 * We need to test this early because xfstests assumes that an

	 * insert range of (0, 1) will return EOPNOTSUPP if the file

	 * system does not support insert range.

	 */

	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)))

		return -EINVAL;

	int ret, depth, split_flag = 0;

	loff_t start;



	trace_ext4_insert_range(inode, offset, len);



	offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);

	len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);



	inode_lock(inode);



	/* Currently just for extent based files */

	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {

		ret = -EOPNOTSUPP;

		goto out_mutex;

		goto out;

	}



	/* Check whether the maximum file size would be exceeded */

	if (len > inode->i_sb->s_maxbytes - inode->i_size) {

		ret = -EFBIG;

		goto out_mutex;

	/* Insert range works only on fs cluster size aligned regions. */

	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) {

		ret = -EINVAL;

		goto out;

	}



	/* Offset must be less than i_size */

	if (offset >= inode->i_size) {

		ret = -EINVAL;

		goto out_mutex;

		goto out;

	}



	/* Check whether the maximum file size would be exceeded */

	if (len > inode->i_sb->s_maxbytes - inode->i_size) {

		ret = -EFBIG;

		goto out;

	}



	/* Wait for existing dio to complete */
@@ -5471,7 +5463,7 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) 


	ret = file_modified(file);

	if (ret)

		goto out_mutex;

		goto out;



	/*

	 * Prevent page faults from reinstantiating pages we have released from
@@ -5481,25 +5473,24 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) 


	ret = ext4_break_layouts(inode);

	if (ret)

		goto out_mmap;

		goto out_invalidate_lock;



	/*

	 * Need to round down to align start offset to page size boundary

	 * for page size > block size.

	 * Write out all dirty pages. Need to round down to align start offset

	 * to page size boundary for page size > block size.

	 */

	ioffset = round_down(offset, PAGE_SIZE);

	/* Write out all dirty pages */

	ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,

			LLONG_MAX);

	start = round_down(offset, PAGE_SIZE);

	ret = filemap_write_and_wait_range(mapping, start, LLONG_MAX);

	if (ret)

		goto out_mmap;

	truncate_pagecache(inode, ioffset);

		goto out_invalidate_lock;



	truncate_pagecache(inode, start);



	credits = ext4_writepage_trans_blocks(inode);

	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);

	if (IS_ERR(handle)) {

		ret = PTR_ERR(handle);

		goto out_mmap;

		goto out_invalidate_lock;

	}

	ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
@@ -5508,16 +5499,19 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) 
	EXT4_I(inode)->i_disksize += len;

	ret = ext4_mark_inode_dirty(handle, inode);

	if (ret)

		goto out_stop;

		goto out_handle;



	start_lblk = offset >> inode->i_blkbits;

	len_lblk = len >> inode->i_blkbits;



	down_write(&EXT4_I(inode)->i_data_sem);

	ext4_discard_preallocations(inode);



	path = ext4_find_extent(inode, offset_lblk, NULL, 0);

	path = ext4_find_extent(inode, start_lblk, NULL, 0);

	if (IS_ERR(path)) {

		up_write(&EXT4_I(inode)->i_data_sem);

		ret = PTR_ERR(path);

		goto out_stop;

		goto out_handle;

	}



	depth = ext_depth(inode);
@@ -5527,16 +5521,16 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) 
		ee_len = ext4_ext_get_actual_len(extent);



		/*

		 * If offset_lblk is not the starting block of extent, split

		 * the extent @offset_lblk

		 * If start_lblk is not the starting block of extent, split

		 * the extent @start_lblk

		 */

		if ((offset_lblk > ee_start_lblk) &&

				(offset_lblk < (ee_start_lblk + ee_len))) {

		if ((start_lblk > ee_start_lblk) &&

				(start_lblk < (ee_start_lblk + ee_len))) {

			if (ext4_ext_is_unwritten(extent))

				split_flag = EXT4_EXT_MARK_UNWRIT1 |

					EXT4_EXT_MARK_UNWRIT2;

			path = ext4_split_extent_at(handle, inode, path,

					offset_lblk, split_flag,

					start_lblk, split_flag,

					EXT4_EX_NOCACHE |

					EXT4_GET_BLOCKS_PRE_IO |

					EXT4_GET_BLOCKS_METADATA_NOFAIL);
@@ -5545,31 +5539,32 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) 
		if (IS_ERR(path)) {

			up_write(&EXT4_I(inode)->i_data_sem);

			ret = PTR_ERR(path);

			goto out_stop;

			goto out_handle;

		}

	}



	ext4_free_ext_path(path);

	ext4_es_remove_extent(inode, offset_lblk, EXT_MAX_BLOCKS - offset_lblk);

	ext4_es_remove_extent(inode, start_lblk, EXT_MAX_BLOCKS - start_lblk);



	/*

	 * if offset_lblk lies in a hole which is at start of file, use

	 * if start_lblk lies in a hole which is at start of file, use

	 * ee_start_lblk to shift extents

	 */

	ret = ext4_ext_shift_extents(inode, handle,

		max(ee_start_lblk, offset_lblk), len_lblk, SHIFT_RIGHT);



		max(ee_start_lblk, start_lblk), len_lblk, SHIFT_RIGHT);

	up_write(&EXT4_I(inode)->i_data_sem);

	if (ret)

		goto out_handle;



	ext4_update_inode_fsync_trans(handle, inode, 1);

	if (IS_SYNC(inode))

		ext4_handle_sync(handle);

	if (ret >= 0)

		ext4_update_inode_fsync_trans(handle, inode, 1);



out_stop:

out_handle:

	ext4_journal_stop(handle);

out_mmap:

out_invalidate_lock:

	filemap_invalidate_unlock(mapping);

out_mutex:

out:

	inode_unlock(inode);

	return ret;

}