6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Xu Yang <xu.yang_2@xxxxxxx>
commit 79c137454815ba5554caa8eeb4ad5c94e96e45ce upstream.
Add mapping_max_folio_size() to get the maximum folio size for this
pagecache mapping.
Fixes: 5d8edfb900d5 ("iomap: Copy larger chunks from userspace")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
Link: https://lore.kernel.org/r/20240521114939.2541461-1-xu.yang_2@xxxxxxx
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/pagemap.h | 34 +++++++++++++++++++++-------------
1 file changed, 21 insertions(+), 13 deletions(-)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -344,6 +344,19 @@ static inline void mapping_set_gfp_mask(
m->gfp_mask = mask;
}
+/*
+ * There are some parts of the kernel which assume that PMD entries
+ * are exactly HPAGE_PMD_ORDER. Those should be fixed, but until then,
+ * limit the maximum allocation order to PMD size. I'm not aware of any
+ * assumptions about maximum order if THP are disabled, but 8 seems like
+ * a good order (that's 1MB if you're using 4kB pages)
+ */
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#define MAX_PAGECACHE_ORDER HPAGE_PMD_ORDER
+#else
+#define MAX_PAGECACHE_ORDER 8
+#endif
+
/**
* mapping_set_large_folios() - Indicate the file supports large folios.
* @mapping: The file.
@@ -370,6 +383,14 @@ static inline bool mapping_large_folio_s
test_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags);
}
+/* Return the maximum folio size for this pagecache mapping, in bytes. */
+static inline size_t mapping_max_folio_size(struct address_space *mapping)
+{
+ if (mapping_large_folio_support(mapping))
+ return PAGE_SIZE << MAX_PAGECACHE_ORDER;
+ return PAGE_SIZE;
+}
+
static inline int filemap_nr_thps(struct address_space *mapping)
{
#ifdef CONFIG_READ_ONLY_THP_FOR_FS
@@ -528,19 +549,6 @@ static inline void *detach_page_private(
return folio_detach_private(page_folio(page));
}
-/*
- * There are some parts of the kernel which assume that PMD entries
- * are exactly HPAGE_PMD_ORDER. Those should be fixed, but until then,
- * limit the maximum allocation order to PMD size. I'm not aware of any
- * assumptions about maximum order if THP are disabled, but 8 seems like
- * a good order (that's 1MB if you're using 4kB pages)
- */
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-#define MAX_PAGECACHE_ORDER HPAGE_PMD_ORDER
-#else
-#define MAX_PAGECACHE_ORDER 8
-#endif
-
#ifdef CONFIG_NUMA
struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order);
#else
