File 3a81ddc.diff of Package openafs

From 3a81ddccd10ed7107f534ae55017a4475eb9466d Mon Sep 17 00:00:00 2001
From: Cheyenne Wills <cwills@sinenomine.net>
Date: Thu, 26 Jun 2025 10:07:20 -0600
Subject: [PATCH] Linux: Refactor afs_linux_write_end()/begin()

Refactor afs_linux_write_end() and afs_linux_write_begin() to separate
the folio and non-folio related code.  This allows reducing some of the
preprocessor statements that are within the body of the functions.

The non-folio related code should be stable, while the folio related
code will see changes in the near future.

There are no intended functional changes in this commit. The new folio
variant of afs_linux_write_begin() now avoids setting the *foliop output
argument on error to be safe, but this should not cause any visible
change in behavior.

Reviewed-on: https://gerrit.openafs.org/16387
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
(cherry picked from commit 53eef69e274aa25b1768442f334a88676abf0011)

Change-Id: I051499b61e035185883eb97fe1a5a6363e50a6b0
---

diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index 2438809..ffa795c 100644
--- a/src/afs/LINUX/osi_vnodeops.c
+++ b/src/afs/LINUX/osi_vnodeops.c
@@ -3620,24 +3620,15 @@
     return 0;
 }
 
-#if defined(STRUCT_ADDRESS_SPACE_OPERATIONS_HAS_WRITE_BEGIN)
-# if defined(HAVE_LINUX_WRITE_BEGIN_END_FOLIO)
+#if defined(HAVE_LINUX_WRITE_BEGIN_END_FOLIO)
 static int
 afs_linux_write_end(struct file *file, struct address_space *mapping,
 		    loff_t pos, unsigned len, unsigned copied,
 		    struct folio *folio, void *fsdata)
-# else
-static int
-afs_linux_write_end(struct file *file, struct address_space *mapping,
-		    loff_t pos, unsigned len, unsigned copied,
-		    struct page *page, void *fsdata)
-# endif
 {
     int code;
     unsigned int from = pos & (PAGE_SIZE - 1);
-# if defined(HAVE_LINUX_WRITE_BEGIN_END_FOLIO)
     struct page *page = &folio->page;
-# endif
 
     code = afs_linux_commit_write(file, page, from, from + copied);
 
@@ -3646,12 +3637,53 @@
     return code;
 }
 
-# if defined(HAVE_LINUX_WRITE_BEGIN_END_FOLIO)
 static int
 afs_linux_write_begin(struct file *file, struct address_space *mapping,
 		      loff_t pos, unsigned len,
 		      struct folio **foliop, void **fsdata)
-# elif defined(HAVE_LINUX_GRAB_CACHE_PAGE_WRITE_BEGIN_NOFLAGS)
+{
+    struct page *page;
+    pgoff_t index = pos >> PAGE_SHIFT;
+    unsigned int from = pos & (PAGE_SIZE - 1);
+    int code;
+
+    page = grab_cache_page_write_begin(mapping, index);
+    if (page == NULL) {
+	return -ENOMEM;
+    }
+
+    code = afs_linux_prepare_write(file, page, from, from + len);
+    if (code) {
+	unlock_page(page);
+	put_page(page);
+	page = NULL;
+    }
+
+    if (page != NULL) {
+	*foliop = page_folio(page);
+    }
+
+    return code;
+}
+
+#elif defined(STRUCT_ADDRESS_SPACE_OPERATIONS_HAS_WRITE_BEGIN)
+
+static int
+afs_linux_write_end(struct file *file, struct address_space *mapping,
+		    loff_t pos, unsigned len, unsigned copied,
+		    struct page *page, void *fsdata)
+{
+    int code;
+    unsigned int from = pos & (PAGE_SIZE - 1);
+
+    code = afs_linux_commit_write(file, page, from, from + copied);
+
+    unlock_page(page);
+    put_page(page);
+    return code;
+}
+
+# if defined(HAVE_LINUX_GRAB_CACHE_PAGE_WRITE_BEGIN_NOFLAGS)
 static int
 afs_linux_write_begin(struct file *file, struct address_space *mapping,
 		      loff_t pos, unsigned len,
@@ -3677,11 +3709,7 @@
 	return -ENOMEM;
     }
 
-# if defined(HAVE_LINUX_WRITE_BEGIN_END_FOLIO)
-    *foliop = page_folio(page);
-# else
     *pagep = page;
-# endif
 
     code = afs_linux_prepare_write(file, page, from, from + len);
     if (code) {
@@ -3691,7 +3719,7 @@
 
     return code;
 }
-#endif /* STRUCT_ADDRESS_SPACE_OPERATIONS_HAS_WRITE_BEGIN */
+#endif /* HAVE_LINUX_WRITE_BEGIN_END_FOLIO */
 
 #ifndef STRUCT_DENTRY_OPERATIONS_HAS_D_AUTOMOUNT
 static void *