generic_file_splice_read is removed

Based on my reading of the gfs2 driver, it appears it's likely the safer
approach to take copy_splice_read instead of filemap_splice_read as it
may potentially lead to cluster deadlocks.

Signed-off-by: Auke Kok <auke.kok@versity.com>

kmod/src/Makefile.kernelcompat

@@ -317,6 +317,15 @@ ifneq (,$(shell grep 'int block_write_full_page.struct page' include/linux/buffe
 ccflags-y += -DKC_HAVE_BLOCK_WRITE_FULL_PAGE
 endif
 
+#
+# v6.4-rc2-29-gc6585011bc1d
+#
+# generic_file_splice_read is removed. It can be replaced with filemap_splice_read
+# or copy_splice_read.
+ifneq (,$(shell grep 'ssize_t generic_file_splice_read.struct file' include/linux/fs.h))
+ccflags-y += -DKC_HAVE_GENERIC_FILE_SPLICE_READ
+endif
+
 #
 # v6.15-13744-g41cb08555c41
 #

kmod/src/data.c

@@ -2266,8 +2266,12 @@ const struct address_space_operations scoutfs_file_aops = {
 const struct file_operations scoutfs_file_fops = {
 	.read_iter	= scoutfs_file_read_iter,
 	.write_iter	= scoutfs_file_write_iter,
-	.splice_read	= generic_file_splice_read,
 	.splice_write	= iter_file_splice_write,
+#ifdef KC_HAVE_GENERIC_FILE_SPLICE_READ
+	.splice_read	= generic_file_splice_read,
+#else
+	.splice_read	= copy_splice_read,
+#endif
 	.mmap		= scoutfs_file_mmap,
 	.unlocked_ioctl	= scoutfs_ioctl,
 	.fsync		= scoutfs_file_fsync,