mirror_zfs/tests/zfs-tests
Brian Atkinson 0e21e473a7 Update pin_user_pages() calls for Direct I/O
Originally #16856 updated Linux Direct I/O requests to use the new
pin_user_pages API. However, it was an oversight that this PR only
handled iov_iter's of type ITER_IOVEC and ITER_UBUF. Other iov_iter
types may try and use the pin_user_pages API if it is available. This
can lead to panics as the iov_iter is not being iterated over correctly
in zfs_uio_pin_user_pages().

Unfortunately, generic iov_iter API's that call pin_user_page_fast() are
protected as GPL only. Rather than update zfs_uio_pin_user_pages() to
account for all iov_iter types, we can simply just call
zfs_uio_get_dio_page_iov_iter() if the iov_iter type is not ITER_IOVEC
or ITER_UBUF. zfs_uio_get_dio_page_iov_iter() calls the
iov_iter_get_pages() calls that can handle any iov_iter type.

In the future it might be worth using the exposed iov_iter iterator
functions that are included in the header iov_iter.h since v6.7. These
functions allow for any iov_iter type to be iterated over and advanced
while applying a step function during iteration. This could possibly be
leveraged in zfs_uio_pin_user_pages().

A new ZFS test case was added to test that a ITER_BVEC is handled
correctly using this new code path. This test case was provided though
issue #16956.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes #16956 
Closes #17006
2025-02-25 22:33:25 +05:00
..
callbacks Split functional testings via github action matrix 2023-03-15 10:41:05 -07:00
cmd tests: fix uClibc for getversion.c 2024-11-14 16:56:34 -08:00
include ZTS: remove get_arcstat 2025-02-25 22:28:46 +05:00
tests Update pin_user_pages() calls for Direct I/O 2025-02-25 22:33:25 +05:00
.gitignore autoconf: use include directives instead of recursing down cmd 2022-05-10 10:18:38 -07:00
Makefile.am ZTS: reimplement kstat helper function 2025-02-25 22:28:14 +05:00