ext4: move out common parts into ext4_fallocate()

[ Upstream commit 2890e5e0 ]

Currently, all zeroing ranges, punch holes, collapse ranges, and insert
ranges first wait for all existing direct I/O workers to complete, and
then they acquire the mapping's invalidate lock before performing the
actual work. These common components are nearly identical, so we can
simplify the code by factoring them out into the ext4_fallocate().

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20241220011637.1157197-11-yi.zhang@huaweicloud.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 29ec9bed ("ext4: fix incorrect punch max_end")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>