[lustre cleanups 5/6] Nuke an unsigned >= 0 assert

Valdis Kletnieks
2015-12-01T22:06:46Z

Writing asserts for almost-never-can-happen things can be valuable.
Writing an assert that tests that an "unsigned int" hasn't gone negative
isn't.

And it generates an *ugly* message:

drivers/staging/lustre/lustre/llite/rw.c:763:20: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
LASSERTF(reserved >= 0, "reserved %lu\n", reserved);
^
include/linux/compiler.h:137:45: note: in definition of macro 'unlikely'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/staging/lustre/lustre/llite/rw.c:763:2: note: in expansion of macro 'LASSERTF'
LASSERTF(reserved >= 0, "reserved %lu\n", reserved);
^
drivers/staging/lustre/lustre/llite/rw.c:763:20: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
LASSERTF(reserved >= 0, "reserved %lu\n", reserved);
^
include/linux/compiler.h:137:53: note: in definition of macro 'unlikely'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/staging/lustre/lustre/llite/rw.c:763:2: note: in expansion of macro 'LASSERTF'
LASSERTF(reserved >= 0, "reserved %lu\n", reserved);
^
drivers/staging/lustre/lustre/llite/rw.c:763:20: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
LASSERTF(reserved >= 0, "reserved %lu\n", reserved);
^
include/linux/compiler.h:110:47: note: in definition of macro 'likely_notrace'
#define likely_notrace(x) __builtin_expect(!!(x), 1)
^
include/linux/compiler.h:137:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
drivers/staging/lustre/lustre/llite/../include/linux/../../../include/linux/libcfs/libcfs_private.h:58:6: note: in expansion of macro 'unlikely'
if (unlikely(!(cond))) { \
^
drivers/staging/lustre/lustre/llite/rw.c:763:2: note: in expansion of macro 'LASSERTF'
LASSERTF(reserved >= 0, "reserved %lu\n", reserved);
^

Umm, thank you, GCC. We'll delete the problem line so ne never see that spew again.

Signed-off-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
---
diff --git a/drivers/staging/lustre/lustre/llite/rw.c b/drivers/staging/lustre/lustre/llite/rw.c
index f79193fa2fb7..39390aab9da2 100644
--- a/drivers/staging/lustre/lustre/llite/rw.c
+++ b/drivers/staging/lustre/lustre/llite/rw.c
@@ -764,7 +764,6 @@ int ll_readahead(const struct lu_env *env, struct cl_io *io,
ret = ll_read_ahead_pages(env, io, queue,
ria, &reserved, mapping, &ra_end);

- LASSERTF(reserved >= 0, "reserved %lu\n", reserved);
if (reserved != 0)
ll_ra_count_put(ll_i2sbi(inode), reserved);

--
2.6.3