From 5a0e3ad6af8660be21ca98a971cd00f331318c05 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Mar 2010 17:04:11 +0900 Subject: include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn --- lib/kref.c | 1 + 1 file changed, 1 insertion(+) (limited to 'lib/kref.c') diff --git a/lib/kref.c b/lib/kref.c index 9ecd6e86561..6d19f690380 100644 --- a/lib/kref.c +++ b/lib/kref.c @@ -13,6 +13,7 @@ #include #include +#include /** * kref_set - initialize object and set refcount to requested number. -- cgit v1.2.3-70-g09d2 From db1afffab0b5d9f6d31f8f4bea44c9cb3bc59351 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 16 Mar 2010 15:14:51 +1100 Subject: kref: remove kref_set Of the three uses of kref_set in the kernel: One really should be kref_put as the code is letting go of a reference, Two really should be kref_init because the kref is being initialised. This suggests that making kref_set available encourages bad code. So fix the three uses and remove kref_set completely. Signed-off-by: NeilBrown Acked-by: Mimi Zohar Acked-by: Serge Hallyn Signed-off-by: Greg Kroah-Hartman --- include/linux/kref.h | 1 - kernel/user_namespace.c | 4 ++-- lib/kref.c | 15 ++------------- security/integrity/ima/ima_iint.c | 4 ++-- 4 files changed, 6 insertions(+), 18 deletions(-) (limited to 'lib/kref.c') diff --git a/include/linux/kref.h b/include/linux/kref.h index baf4b9e4b19..6cc38fc07ab 100644 --- a/include/linux/kref.h +++ b/include/linux/kref.h @@ -21,7 +21,6 @@ struct kref { atomic_t refcount; }; -void kref_set(struct kref *kref, int num); void kref_init(struct kref *kref); void kref_get(struct kref *kref); int kref_put(struct kref *kref, void (*release) (struct kref *kref)); diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 076c7c8215b..b2d70d38dff 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -54,8 +54,8 @@ int create_user_ns(struct cred *new) #endif /* tgcred will be cleared in our caller bc CLONE_THREAD won't be set */ - /* alloc_uid() incremented the userns refcount. Just set it to 1 */ - kref_set(&ns->kref, 1); + /* root_user holds a reference to ns, our reference can be dropped */ + put_user_ns(ns); return 0; } diff --git a/lib/kref.c b/lib/kref.c index 6d19f690380..d3d227a08a4 100644 --- a/lib/kref.c +++ b/lib/kref.c @@ -15,24 +15,14 @@ #include #include -/** - * kref_set - initialize object and set refcount to requested number. - * @kref: object in question. - * @num: initial reference counter - */ -void kref_set(struct kref *kref, int num) -{ - atomic_set(&kref->refcount, num); - smp_mb(); -} - /** * kref_init - initialize object. * @kref: object in question. */ void kref_init(struct kref *kref) { - kref_set(kref, 1); + atomic_set(&kref->refcount, 1); + smp_mb(); } /** @@ -72,7 +62,6 @@ int kref_put(struct kref *kref, void (*release)(struct kref *kref)) return 0; } -EXPORT_SYMBOL(kref_set); EXPORT_SYMBOL(kref_init); EXPORT_SYMBOL(kref_get); EXPORT_SYMBOL(kref_put); diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c index 2dc2d659414..7625b85c227 100644 --- a/security/integrity/ima/ima_iint.c +++ b/security/integrity/ima/ima_iint.c @@ -94,7 +94,7 @@ void iint_free(struct kref *kref) iint->opencount); iint->opencount = 0; } - kref_set(&iint->refcount, 1); + kref_init(&iint->refcount); kmem_cache_free(iint_cache, iint); } @@ -133,7 +133,7 @@ static void init_once(void *foo) iint->readcount = 0; iint->writecount = 0; iint->opencount = 0; - kref_set(&iint->refcount, 1); + kref_init(&iint->refcount); } static int __init ima_iintcache_init(void) -- cgit v1.2.3-70-g09d2