ext4: use kiocb_modified instead of file_modified in DIO/DAX write path

file_modified() passes flags=0 which drops IOCB_NOWAIT, causing
file_update_time() to sleep in ext4_journal_start() via
ext4_dirty_inode() even in non-blocking contexts.

kiocb_modified(iocb) propagates iocb->ki_flags so that
generic_update_time() correctly returns -EAGAIN when IOCB_NOWAIT
is set and ->dirty_inode could block, matching the behavior
already adopted by XFS, FUSE, and ext2.

Affected paths:
- ext4_dio_write_checks(): DIO NOWAIT write
- ext4_write_checks(): shared by buffered (rejects NOWAIT upfront)
  and DAX write (supports NOWAIT)

ext4_fallocate() in extents.c is not affected as it has no kiocb.

Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260629113827.4074335-6-libaokun@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

0 files changed, 0 insertions, 0 deletions