Linux 5.18 compat: use address_space_operations->readahead

->readpages was removed and replaced by ->readahead. Define zpl_readahead for kernels that don't have ->readpages. Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Riccardo Schirone <[email protected]> Closes #13278
openzfs · Apr 6, 2022 · 35ddd8e · 35ddd8e
1 parent 10a9f5f
commit 35ddd8e
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diff --git a/config/kernel-readpages.m4 b/config/kernel-readpages.m4
@@ -0,0 +1,25 @@
+dnl #
+dnl # Linux 5.18 removes address_space_operations ->readpages in favour of
+dnl # ->readahead
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_VFS_READPAGES], [
+	ZFS_LINUX_TEST_SRC([vfs_has_readpages], [
+		#include <linux/fs.h>
+
+		static const struct address_space_operations
+		    aops __attribute__ ((unused)) = {
+			.readpages = NULL,
+		};
+	],[])
+])
+
+AC_DEFUN([ZFS_AC_KERNEL_VFS_READPAGES], [
+	AC_MSG_CHECKING([address_space_operations->readpages exists])
+	ZFS_LINUX_TEST_RESULT([vfs_has_readpages], [
+		AC_MSG_RESULT([yes])
+		AC_DEFINE(HAVE_VFS_READPAGES, 1,
+			[address_space_operations->readpages exists])
+	],[
+		AC_MSG_RESULT([no])
+	])
+])
diff --git a/config/kernel.m4 b/config/kernel.m4
@@ -132,6 +132,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
 	ZFS_AC_KERNEL_SRC_SIGNAL_STOP
 	ZFS_AC_KERNEL_SRC_SIGINFO
 	ZFS_AC_KERNEL_SRC_SET_SPECIAL_STATE
+	ZFS_AC_KERNEL_SRC_VFS_READPAGES
 	ZFS_AC_KERNEL_SRC_VFS_SET_PAGE_DIRTY_NOBUFFERS
 	ZFS_AC_KERNEL_SRC_STANDALONE_LINUX_STDARG
 	ZFS_AC_KERNEL_SRC_PAGEMAP_FOLIO_WAIT_BIT
@@ -242,6 +243,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
 	ZFS_AC_KERNEL_SIGNAL_STOP
 	ZFS_AC_KERNEL_SIGINFO
 	ZFS_AC_KERNEL_SET_SPECIAL_STATE
+	ZFS_AC_KERNEL_VFS_READPAGES
 	ZFS_AC_KERNEL_VFS_SET_PAGE_DIRTY_NOBUFFERS
 	ZFS_AC_KERNEL_STANDALONE_LINUX_STDARG
 	ZFS_AC_KERNEL_PAGEMAP_FOLIO_WAIT_BIT

diff --git a/module/os/linux/zfs/zpl_file.c b/module/os/linux/zfs/zpl_file.c
@@ -647,12 +647,29 @@ zpl_readpage_filler(void *data, struct page *pp)
  * paging.  For simplicity, the code relies on read_cache_pages() to
  * correctly lock each page for IO and call zpl_readpage().
  */
+#ifdef HAVE_VFS_READPAGES
 static int
 zpl_readpages(struct file *filp, struct address_space *mapping,
     struct list_head *pages, unsigned nr_pages)
 {
 	return (read_cache_pages(mapping, pages, zpl_readpage_filler, NULL));
 }
+#else
+static void
+zpl_readahead(struct readahead_control *ractl)
+{
+	struct page *page;
+
+	while ((page = readahead_page(ractl)) != NULL) {
+		int ret;
+
+		ret = zpl_readpage_filler(NULL, page);
+		put_page(page);
+		if (ret)
+			break;
+	}
+}
+#endif
 
 static int
 zpl_putpage(struct page *pp, struct writeback_control *wbc, void *data)
@@ -1027,7 +1044,11 @@ zpl_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 
 
 const struct address_space_operations zpl_address_space_operations = {
+#ifdef HAVE_VFS_READPAGES
 	.readpages	= zpl_readpages,
+#else
+	.readahead	= zpl_readahead,
+#endif
 	.readpage	= zpl_readpage,
 	.writepage	= zpl_writepage,
 	.writepages	= zpl_writepages,