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authorJ. Bruce Fields <bfields@citi.umich.edu>2009-08-21 11:27:29 -0400
committerJ. Bruce Fields <bfields@citi.umich.edu>2009-08-21 11:27:29 -0400
commite9dc122166b8d863d3057a66ada04838e5548e52 (patch)
tree749e15bf719b64bf9113db7acd8e043d9742cb26 /include/linux/flex_array.h
parent560ab42ef923aaf2e4347315bdfcc74b2708972c (diff)
parent405d8f8b1d936414da2093d4149ff790ff3f84a5 (diff)
Merge branch 'nfs-for-2.6.32' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6 into for-2.6.32-incoming
Conflicts: net/sunrpc/cache.c
Diffstat (limited to 'include/linux/flex_array.h')
-rw-r--r--include/linux/flex_array.h47
1 files changed, 47 insertions, 0 deletions
diff --git a/include/linux/flex_array.h b/include/linux/flex_array.h
new file mode 100644
index 000000000000..23c1ec79a31b
--- /dev/null
+++ b/include/linux/flex_array.h
@@ -0,0 +1,47 @@
+#ifndef _FLEX_ARRAY_H
+#define _FLEX_ARRAY_H
+
+#include <linux/types.h>
+#include <asm/page.h>
+
+#define FLEX_ARRAY_PART_SIZE PAGE_SIZE
+#define FLEX_ARRAY_BASE_SIZE PAGE_SIZE
+
+struct flex_array_part;
+
+/*
+ * This is meant to replace cases where an array-like
+ * structure has gotten too big to fit into kmalloc()
+ * and the developer is getting tempted to use
+ * vmalloc().
+ */
+
+struct flex_array {
+ union {
+ struct {
+ int element_size;
+ int total_nr_elements;
+ struct flex_array_part *parts[0];
+ };
+ /*
+ * This little trick makes sure that
+ * sizeof(flex_array) == PAGE_SIZE
+ */
+ char padding[FLEX_ARRAY_BASE_SIZE];
+ };
+};
+
+#define FLEX_ARRAY_INIT(size, total) { { {\
+ .element_size = (size), \
+ .total_nr_elements = (total), \
+} } }
+
+struct flex_array *flex_array_alloc(int element_size, int total, gfp_t flags);
+int flex_array_prealloc(struct flex_array *fa, int start, int end, gfp_t flags);
+void flex_array_free(struct flex_array *fa);
+void flex_array_free_parts(struct flex_array *fa);
+int flex_array_put(struct flex_array *fa, int element_nr, void *src,
+ gfp_t flags);
+void *flex_array_get(struct flex_array *fa, int element_nr);
+
+#endif /* _FLEX_ARRAY_H */