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make buffer head argument of buffer_##name "const"

PATCH In review Werner Almesberger 2 participants 3 messages Oct 26, 2004

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Werner Almesberger

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#0 lore raw

PATCH 1/1 make buffer head argument of buffer_##name "const"

This one is embarrassingly simple. Unfortunately, it doesn't meet the requirements for the patch monkey, so here goes a "regular" submission.

I've checked that the argument of test_bit is indeed "const" on all architectures. The patch is for 2.6.9.

- Werner

---------------------------------- cut here -----------------------------------

Signed-off-by Werner Almesberger <[email protected]>
include/linux/buffer_head.h renamed from include/linux/buffer_head.h.orig +1 -1
@@ -76,7 +76,7 @@
 {									\
 	clear_bit(BH_##bit, &(bh)->b_state);				\
 }									\
-static inline int buffer_##name(struct buffer_head *bh)			\
+static inline int buffer_##name(const struct buffer_head *bh)		\
 {									\
 	return test_bit(BH_##bit, &(bh)->b_state);			\
 }
Signature · 3 lines
  _________________________________________________________________________
 / Werner Almesberger, Buenos Aires, Argentina     [email protected] /
/_http://www.almesberger.net/____________________________________________/
#1 lore raw
Quoted 12 lines · Werner Almesberger

--- linux-2.6.9/include/linux/buffer_head.h.orig Tue Oct 26 02:57:54 2004
+++ linux-2.6.9/include/linux/buffer_head.h Tue Oct 26 02:21:04 2004
@@ -76,7 +76,7 @@
{ \
clear_bit(BH_##bit, &(bh)->b_state); \
} \
-static inline int buffer_##name(struct buffer_head *bh) \
+static inline int buffer_##name(const struct buffer_head *bh) \
{ \
return test_bit(BH_##bit, &(bh)->b_state); \
}

OK, but why? Does it generate better code or something?

author
#2 lore raw
Quoted 1 line · Andrew Morton

OK, but why? Does it generate better code or something?

I wouldn't expect this to change the resulting code. It's just so that one can feed it a "const" pointer, which allows other functions to use "const", etc.

- Werner

Signature · 3 lines
  _________________________________________________________________________
 / Werner Almesberger, Buenos Aires, Argentina     [email protected] /
/_http://www.almesberger.net/____________________________________________/