From ffd6978ef59cfe2773e984bf03de2f0b93b03f5c Mon Sep 17 00:00:00 2001 From: Coleman Kane Date: Sat, 20 Mar 2021 01:33:42 -0400 Subject: [PATCH] Linux 5.12 update: bio_max_segs() replaces BIO_MAX_PAGES The BIO_MAX_PAGES macro is being retired in favor of a bio_max_segs() function that implements the typical MIN(x,y) logic used throughout the kernel for bounding the allocation, and also the new implementation is intended to be signed-safe (which the former was not). Reviewed-by: Tony Hutter Reviewed-by: Brian Behlendorf Signed-off-by: Coleman Kane Closes #11765 --- config/kernel-bio_max_segs.m4 | 23 +++++++++++++++++++++++ config/kernel.m4 | 2 ++ module/os/linux/zfs/vdev_disk.c | 5 +++++ 3 files changed, 30 insertions(+) create mode 100644 config/kernel-bio_max_segs.m4 diff --git a/config/kernel-bio_max_segs.m4 b/config/kernel-bio_max_segs.m4 new file mode 100644 index 000000000000..a90d75455c13 --- /dev/null +++ b/config/kernel-bio_max_segs.m4 @@ -0,0 +1,23 @@ +dnl # +dnl # 5.12 API change removes BIO_MAX_PAGES in favor of bio_max_segs() +dnl # which will handle the logic of setting the upper-bound to a +dnl # BIO_MAX_PAGES, internally. +dnl # +AC_DEFUN([ZFS_AC_KERNEL_SRC_BIO_MAX_SEGS], [ + ZFS_LINUX_TEST_SRC([bio_max_segs], [ + #include + ],[ + bio_max_segs(1); + ]) +]) + +AC_DEFUN([ZFS_AC_KERNEL_BIO_MAX_SEGS], [ + AC_MSG_CHECKING([whether bio_max_segs() exists]) + ZFS_LINUX_TEST_RESULT([bio_max_segs], [ + AC_MSG_RESULT(yes) + + AC_DEFINE([HAVE_BIO_MAX_SEGS], 1, [bio_max_segs() is implemented]) + ],[ + AC_MSG_RESULT(no) + ]) +]) diff --git a/config/kernel.m4 b/config/kernel.m4 index 24db38f09f43..dfb6165d879d 100644 --- a/config/kernel.m4 +++ b/config/kernel.m4 @@ -128,6 +128,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [ ZFS_AC_KERNEL_SRC_GENERIC_FILLATTR_USERNS ZFS_AC_KERNEL_SRC_MKNOD ZFS_AC_KERNEL_SRC_SYMLINK + ZFS_AC_KERNEL_SRC_BIO_MAX_SEGS AC_MSG_CHECKING([for available kernel interfaces]) ZFS_LINUX_TEST_COMPILE_ALL([kabi]) @@ -229,6 +230,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [ ZFS_AC_KERNEL_GENERIC_FILLATTR_USERNS ZFS_AC_KERNEL_MKNOD ZFS_AC_KERNEL_SYMLINK + ZFS_AC_KERNEL_BIO_MAX_SEGS ]) dnl # diff --git a/module/os/linux/zfs/vdev_disk.c b/module/os/linux/zfs/vdev_disk.c index ff71ef4cd065..c56fd3a6ff21 100644 --- a/module/os/linux/zfs/vdev_disk.c +++ b/module/os/linux/zfs/vdev_disk.c @@ -589,9 +589,14 @@ __vdev_disk_physio(struct block_device *bdev, zio_t *zio, } /* bio_alloc() with __GFP_WAIT never returns NULL */ +#ifdef HAVE_BIO_MAX_SEGS + dr->dr_bio[i] = bio_alloc(GFP_NOIO, bio_max_segs( + abd_nr_pages_off(zio->io_abd, bio_size, abd_offset))); +#else dr->dr_bio[i] = bio_alloc(GFP_NOIO, MIN(abd_nr_pages_off(zio->io_abd, bio_size, abd_offset), BIO_MAX_PAGES)); +#endif if (unlikely(dr->dr_bio[i] == NULL)) { vdev_disk_dio_free(dr); return (SET_ERROR(ENOMEM));