aboutsummaryrefslogtreecommitdiffstats
path: root/config/kernel.m4
diff options
context:
space:
mode:
authorBrian Behlendorf <[email protected]>2020-12-18 08:48:26 -0800
committerGitHub <[email protected]>2020-12-18 08:48:26 -0800
commit1c2358c12a673759845f70c57dade601cc12ed99 (patch)
tree4332a0dc842d4c9476fdb19923eff3a1e00e1d86 /config/kernel.m4
parent2844ad60d41717f4713ed01df2d46bc12f590ddd (diff)
Linux 5.10 compat: use iov_iter in uio structure
As of the 5.10 kernel the generic splice compatibility code has been removed. All filesystems are now responsible for registering a ->splice_read and ->splice_write callback to support this operation. The good news is the VFS provided generic_file_splice_read() and iter_file_splice_write() callbacks can be used provided the ->iter_read and ->iter_write callback support pipes. However, this is currently not the case and only iovecs and bvecs (not pipes) are ever attached to the uio structure. This commit changes that by allowing full iov_iter structures to be attached to uios. Ever since the 4.9 kernel the iov_iter structure has supported iovecs, kvecs, bvevs, and pipes so it's desirable to pass the entire thing when possible. In conjunction with this the uio helper functions (i.e uiomove(), uiocopy(), etc) have been updated to understand the new UIO_ITER type. Note that using the kernel provided uio_iter interfaces allowed the existing Linux specific uio handling code to be simplified. When there's no longer a need to support kernel's older than 4.9, then it will be possible to remove the iovec and bvec members from the uio structure and always use a uio_iter. Until then we need to maintain all of the existing types for older kernels. Some additional refactoring and cleanup was included in this change: - Added checks to configure to detect available iov_iter interfaces. Some are available all the way back to the 3.10 kernel and are used when available. In particular, uio_prefaultpages() now always uses iov_iter_fault_in_readable() which is available for all supported kernels. - The unused UIO_USERISPACE type has been removed. It is no longer needed now that the uio_seg enum is platform specific. - Moved zfs_uio.c from the zcommon.ko module to the Linux specific platform code for the zfs.ko module. This gets it out of libzfs where it was never needed and keeps this Linux specific code out of the common sources. - Removed unnecessary O_APPEND handling from zfs_iter_write(), this is redundant and O_APPEND is already handled in zfs_write(); Reviewed-by: Colin Ian King <[email protected]> Reviewed-by: Tony Hutter <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #11351
Diffstat (limited to 'config/kernel.m4')
-rw-r--r--config/kernel.m42
1 files changed, 2 insertions, 0 deletions
diff --git a/config/kernel.m4 b/config/kernel.m4
index 14a8d4c58..5377bcadd 100644
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -106,6 +106,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
ZFS_AC_KERNEL_SRC_VFS_DIRECT_IO
ZFS_AC_KERNEL_SRC_VFS_RW_ITERATE
ZFS_AC_KERNEL_SRC_VFS_GENERIC_WRITE_CHECKS
+ ZFS_AC_KERNEL_SRC_VFS_IOV_ITER
ZFS_AC_KERNEL_SRC_KMAP_ATOMIC_ARGS
ZFS_AC_KERNEL_SRC_FOLLOW_DOWN_ONE
ZFS_AC_KERNEL_SRC_MAKE_REQUEST_FN
@@ -204,6 +205,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
ZFS_AC_KERNEL_VFS_DIRECT_IO
ZFS_AC_KERNEL_VFS_RW_ITERATE
ZFS_AC_KERNEL_VFS_GENERIC_WRITE_CHECKS
+ ZFS_AC_KERNEL_VFS_IOV_ITER
ZFS_AC_KERNEL_KMAP_ATOMIC_ARGS
ZFS_AC_KERNEL_FOLLOW_DOWN_ONE
ZFS_AC_KERNEL_MAKE_REQUEST_FN