From c74a17a498df6ad40871cf146c5d1e2e5119aca9 Mon Sep 17 00:00:00 2001
From: Coleman Kane <ckane@colemankane.org>
Date: Tue, 8 Aug 2023 18:42:32 -0400
Subject: [PATCH] Linux 6.5 compat: Use copy_splice_read instead of
filemap_splice_read
Using the filemap_splice_read function for the splice_read handler was
leading to occasional data corruption under certain circumstances. Favor
using copy_splice_read instead, which does not demonstrate the same
erroneous behavior under the tested failure cases.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes #15164
---
config/kernel-filemap-splice-read.m4 | 18 +++++++++---------
config/kernel.m4 | 4 ++--
module/os/linux/zfs/zpl_file.c | 4 ++--
3 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/config/kernel-filemap-splice-read.m4 b/config/kernel-filemap-splice-read.m4
index 5199b7373e..4c83b31d73 100644
--- a/config/kernel-filemap-splice-read.m4
+++ b/config/kernel-filemap-splice-read.m4
@@ -1,24 +1,24 @@
-AC_DEFUN([ZFS_AC_KERNEL_SRC_FILEMAP_SPLICE_READ], [
+AC_DEFUN([ZFS_AC_KERNEL_SRC_COPY_SPLICE_READ], [
dnl #
dnl # Kernel 6.5 - generic_file_splice_read was removed in favor
- dnl # of filemap_splice_read for the .splice_read member of the
+ dnl # of copy_splice_read for the .splice_read member of the
dnl # file_operations struct.
dnl #
- ZFS_LINUX_TEST_SRC([has_filemap_splice_read], [
+ ZFS_LINUX_TEST_SRC([has_copy_splice_read], [
#include <linux/fs.h>
struct file_operations fops __attribute__((unused)) = {
- .splice_read = filemap_splice_read,
+ .splice_read = copy_splice_read,
};
],[])
])
-AC_DEFUN([ZFS_AC_KERNEL_FILEMAP_SPLICE_READ], [
- AC_MSG_CHECKING([whether filemap_splice_read() exists])
- ZFS_LINUX_TEST_RESULT([has_filemap_splice_read], [
+AC_DEFUN([ZFS_AC_KERNEL_COPY_SPLICE_READ], [
+ AC_MSG_CHECKING([whether copy_splice_read() exists])
+ ZFS_LINUX_TEST_RESULT([has_copy_splice_read], [
AC_MSG_RESULT(yes)
- AC_DEFINE(HAVE_FILEMAP_SPLICE_READ, 1,
- [filemap_splice_read exists])
+ AC_DEFINE(HAVE_COPY_SPLICE_READ, 1,
+ [copy_splice_read exists])
],[
AC_MSG_RESULT(no)
])
diff --git a/config/kernel.m4 b/config/kernel.m4
index 3edcb5da22..b81200f5bf 100644
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -149,7 +149,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
ZFS_AC_KERNEL_SRC_WRITEPAGE_T
ZFS_AC_KERNEL_SRC_RECLAIMED
ZFS_AC_KERNEL_SRC_REGISTER_SYSCTL_TABLE
- ZFS_AC_KERNEL_SRC_FILEMAP_SPLICE_READ
+ ZFS_AC_KERNEL_SRC_COPY_SPLICE_READ
case "$host_cpu" in
powerpc*)
ZFS_AC_KERNEL_SRC_CPU_HAS_FEATURE
@@ -278,7 +278,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
ZFS_AC_KERNEL_WRITEPAGE_T
ZFS_AC_KERNEL_RECLAIMED
ZFS_AC_KERNEL_REGISTER_SYSCTL_TABLE
- ZFS_AC_KERNEL_FILEMAP_SPLICE_READ
+ ZFS_AC_KERNEL_COPY_SPLICE_READ
case "$host_cpu" in
powerpc*)
ZFS_AC_KERNEL_CPU_HAS_FEATURE
diff --git a/module/os/linux/zfs/zpl_file.c b/module/os/linux/zfs/zpl_file.c
index d982ceb98f..c880e015ae 100644
--- a/module/os/linux/zfs/zpl_file.c
+++ b/module/os/linux/zfs/zpl_file.c
@@ -1142,8 +1142,8 @@ const struct file_operations zpl_file_operations = {
.read_iter = zpl_iter_read,
.write_iter = zpl_iter_write,
#ifdef HAVE_VFS_IOV_ITER
-#ifdef HAVE_FILEMAP_SPLICE_READ
- .splice_read = filemap_splice_read,
+#ifdef HAVE_COPY_SPLICE_READ
+ .splice_read = copy_splice_read,
#else
.splice_read = generic_file_splice_read,
#endif