sysv: remove writepage implementation

If the filesystem implements migrate_folio and writepages, there is no
need for a writepage implementation.

Link: https://lkml.kernel.org/r/20231215200245.748418-12-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/sysv/itree.c

@@ -8,6 +8,7 @@
 
 #include <linux/buffer_head.h>
 #include <linux/mount.h>
+#include <linux/mpage.h>
 #include <linux/string.h>
 #include "sysv.h"
 
@@ -456,9 +457,10 @@ int sysv_getattr(struct mnt_idmap *idmap, const struct path *path,
 	return 0;
 }
 
-static int sysv_writepage(struct page *page, struct writeback_control *wbc)
+static int sysv_writepages(struct address_space *mapping,
+		struct writeback_control *wbc)
 {
-	return block_write_full_page(page,get_block,wbc);
+	return mpage_writepages(mapping, wbc, get_block);
 }
 
 static int sysv_read_folio(struct file *file, struct folio *folio)
@@ -503,8 +505,9 @@ const struct address_space_operations sysv_aops = {
 	.dirty_folio = block_dirty_folio,
 	.invalidate_folio = block_invalidate_folio,
 	.read_folio = sysv_read_folio,
-	.writepage = sysv_writepage,
+	.writepages = sysv_writepages,
 	.write_begin = sysv_write_begin,
 	.write_end = generic_write_end,
+	.migrate_folio = buffer_migrate_folio,
 	.bmap = sysv_bmap
 };