ext2, ext4: fix issue with missing journal entry in ext4_dax_mkwrite()

As it is currently written ext4_dax_mkwrite() assumes that the call into
__dax_mkwrite() will not have to do a block allocation so it doesn't create
a journal entry.  For a read that creates a zero page to cover a hole
followed by a write that actually allocates storage this is incorrect.  The
ext4_dax_mkwrite() -> __dax_mkwrite() -> __dax_fault() path calls
get_blocks() to allocate storage.

Fix this by having the ->page_mkwrite fault handler call ext4_dax_fault()
as this function already has all the logic needed to allocate a journal
entry and call __dax_fault().

Also update the ext2 fault handlers in this same way to remove duplicate
code and keep the logic between ext2 and ext4 the same.

Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Ross Zwisler <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>

0 files changed, 0 insertions, 0 deletions