Btrfs: Fix sparse endian warnings in struct-funcs.c

The btrfs macros to access individual struct members on disk were
sending the same variable to functions that expected different types
of endianness.  This fix explicitly creates a variable of the correct
type instead of abusing a single variable for mixed purposes.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index cdedbe144d45ae9b55385e3868ca00b72dc140e7..8d7f568009c9838966c23a8ea6ba468fbd8bc03c 100644 (file)
--- a/fs/btrfs/struct-funcs.c
+++ b/fs/btrfs/struct-funcs.c
@@ -36,9 +36,14 @@
  * The extent buffer api is used to do all the kmapping and page
  * spanning work required to get extent buffers in highmem and have
  * a metadata blocksize different from the page size.
+ *
+ * The macro starts with a simple function prototype declaration so that
+ * sparse won't complain about it being static.
  */
 
 #define BTRFS_SETGET_FUNCS(name, type, member, bits)                   \
+u##bits btrfs_##name(struct extent_buffer *eb, type *s);               \
+void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val); \
 u##bits btrfs_##name(struct extent_buffer *eb,                         \
                                   type *s)                             \
 {                                                                      \
@@ -59,14 +64,15 @@ u##bits btrfs_##name(struct extent_buffer *eb,                              \
                int unmap_on_exit = (eb->map_token == NULL);            \
                unsigned long map_start;                                \
                unsigned long map_len;                                  \
-               __le##bits res;                                         \
+               u##bits res;                                            \
                err = map_extent_buffer(eb, offset,                     \
                                sizeof(((type *)0)->member),            \
                                &map_token, &kaddr,                     \
                                &map_start, &map_len, KM_USER1);        \
                if (err) {                                              \
-                       read_eb_member(eb, s, type, member, &res);      \
-                       return le##bits##_to_cpu(res);                  \
+                       __le##bits leres;                               \
+                       read_eb_member(eb, s, type, member, &leres);    \
+                       return le##bits##_to_cpu(leres);                \
                }                                                       \
                p = (type *)(kaddr + part_offset - map_start);          \
                res = le##bits##_to_cpu(p->member);                     \
@@ -101,8 +107,9 @@ void btrfs_set_##name(struct extent_buffer *eb,                             \
                                &map_token, &kaddr,                     \
                                &map_start, &map_len, KM_USER1);        \
                if (err) {                                              \
-                       val = cpu_to_le##bits(val);                     \
-                       write_eb_member(eb, s, type, member, &val);     \
+                       __le##bits val2;                                \
+                       val2 = cpu_to_le##bits(val);                    \
+                       write_eb_member(eb, s, type, member, &val2);    \
                        return;                                         \
                }                                                       \
                p = (type *)(kaddr + part_offset - map_start);          \