From 2cda2728aa1c8c006418a24f867b25e5eb7a32e2 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Mon, 15 Mar 2010 12:46:51 +0100 Subject: block: Fix overrun in lcm() and move it to lib lcm() was defined to take integer-sized arguments. The supplied arguments are multiplied, however, causing us to overflow given sufficiently large input. That in turn led to incorrect optimal I/O size reporting in some cases (RAID over RAID). Switch lcm() over to unsigned long similar to gcd() and move the function from blk-settings.c to lib. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- lib/Makefile | 2 +- lib/lcm.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) create mode 100644 lib/lcm.c (limited to 'lib') diff --git a/lib/Makefile b/lib/Makefile index 2e152ae..0d40152 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -21,7 +21,7 @@ lib-y += kobject.o kref.o klist.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ - string_helpers.o gcd.o list_sort.o + string_helpers.o gcd.o lcm.o list_sort.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/lcm.c b/lib/lcm.c new file mode 100644 index 0000000..157cd88 --- /dev/null +++ b/lib/lcm.c @@ -0,0 +1,15 @@ +#include +#include +#include + +/* Lowest common multiple */ +unsigned long lcm(unsigned long a, unsigned long b) +{ + if (a && b) + return (a * b) / gcd(a, b); + else if (b) + return b; + + return a; +} +EXPORT_SYMBOL_GPL(lcm); -- cgit v1.1 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/cpumask.c | 1 + lib/crc32.c | 1 - lib/debugobjects.c | 1 + lib/devres.c | 1 + lib/dynamic_debug.c | 1 + lib/genalloc.c | 1 + lib/inflate.c | 1 + lib/kasprintf.c | 1 + lib/kobject_uevent.c | 1 + lib/kref.c | 1 + lib/radix-tree.c | 1 - lib/scatterlist.c | 1 + lib/swiotlb.c | 1 + lib/textsearch.c | 1 + 14 files changed, 12 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/cpumask.c b/lib/cpumask.c index 7bb4142..05d6aca 100644 --- a/lib/cpumask.c +++ b/lib/cpumask.c @@ -1,3 +1,4 @@ +#include #include #include #include diff --git a/lib/crc32.c b/lib/crc32.c index 0f45fbf..bc5b936 100644 --- a/lib/crc32.c +++ b/lib/crc32.c @@ -25,7 +25,6 @@ #include #include #include -#include #include #include #include "crc32defs.h" diff --git a/lib/debugobjects.c b/lib/debugobjects.c index a9a8996..b862b30 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #define ODEBUG_HASH_BITS 14 diff --git a/lib/devres.c b/lib/devres.c index 72c8909..4936860 100644 --- a/lib/devres.c +++ b/lib/devres.c @@ -1,5 +1,6 @@ #include #include +#include #include void devm_ioremap_release(struct device *dev, void *res) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index f935029..d6b8b9b 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -25,6 +25,7 @@ #include #include #include +#include extern struct _ddebug __start___verbose[]; extern struct _ddebug __stop___verbose[]; diff --git a/lib/genalloc.c b/lib/genalloc.c index e67f974..736c3b0 100644 --- a/lib/genalloc.c +++ b/lib/genalloc.c @@ -10,6 +10,7 @@ * Version 2. See the file COPYING for more details. */ +#include #include #include #include diff --git a/lib/inflate.c b/lib/inflate.c index d102559..677b738 100644 --- a/lib/inflate.c +++ b/lib/inflate.c @@ -103,6 +103,7 @@ the two sets of lengths. */ #include +#include #ifdef RCSID static char rcsid[] = "#Id: inflate.c,v 0.14 1993/06/10 13:27:04 jloup Exp #"; diff --git a/lib/kasprintf.c b/lib/kasprintf.c index c5ff1fd..9c4233b 100644 --- a/lib/kasprintf.c +++ b/lib/kasprintf.c @@ -6,6 +6,7 @@ #include #include +#include #include #include diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index c9d3a3e..7b48d44 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include diff --git a/lib/kref.c b/lib/kref.c index 9ecd6e8..6d19f69 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. diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 6b9670d..0871582 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -28,7 +28,6 @@ #include #include #include -#include #include #include #include diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 0d475d8..9afa25b 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -7,6 +7,7 @@ * Version 2. See the file COPYING for more details. */ #include +#include #include #include diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 437eedb..5fddf72 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include diff --git a/lib/textsearch.c b/lib/textsearch.c index 9fbcb44..d608331 100644 --- a/lib/textsearch.c +++ b/lib/textsearch.c @@ -103,6 +103,7 @@ #include #include #include +#include static LIST_HEAD(ts_ops); static DEFINE_SPINLOCK(ts_mod_lock); -- cgit v1.1 From 47c4c864af60d14926f4017d23968a8341b8ab9f Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Tue, 6 Apr 2010 10:19:30 +0200 Subject: microblaze: Enable memory leak detector Enable DEBUG_KMEMLEAK for microblaze Signed-off-by: Michal Simek --- lib/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1fafb4b..ff01710 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -356,7 +356,7 @@ config SLUB_STATS config DEBUG_KMEMLEAK bool "Kernel memory leak detector" depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \ - (X86 || ARM || PPC || S390 || SUPERH) + (X86 || ARM || PPC || S390 || SUPERH || MICROBLAZE) select DEBUG_FS if SYSFS select STACKTRACE if STACKTRACE_SUPPORT -- cgit v1.1 From 2a7268abc48c8009b284bd88605d14fcb65772ec Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Tue, 6 Apr 2010 14:35:01 -0700 Subject: ratelimit: annotate ___ratelimit() To prevent from wrongly using the return value. [akpm@linux-foundation.org: fix spello] Signed-off-by: Yong Zhang Cc: Ingo Molnar Cc: Dave Young Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/ratelimit.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/ratelimit.c b/lib/ratelimit.c index 09f5ce1..b4cd24f 100644 --- a/lib/ratelimit.c +++ b/lib/ratelimit.c @@ -16,9 +16,14 @@ /* * __ratelimit - rate limiting * @rs: ratelimit_state data + * @func: name of calling function * - * This enforces a rate limit: not more than @rs->ratelimit_burst callbacks - * in every @rs->ratelimit_jiffies + * This enforces a rate limit: not more than @rs->burst callbacks + * in every @rs->interval + * + * RETURNS: + * 0 means callbacks will be suppressed. + * 1 means go ahead and do it. */ int ___ratelimit(struct ratelimit_state *rs, const char *func) { -- cgit v1.1 From 57119c34e53bbb8d244c3ff1335ef5145768538f Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Tue, 6 Apr 2010 14:35:03 -0700 Subject: ratelimit: fix the return value when __ratelimit() fails to acquire the lock The log of commit edaac8e3167501cda336231d00611bf59c164346 ("ratelimit: Fix/allow use in atomic contexts"), indicates that we want to suppress the callback when the trylock fails. Signed-off-by: Yong Zhang Cc: Ingo Molnar Cc: Christian Borntraeger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/ratelimit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/ratelimit.c b/lib/ratelimit.c index b4cd24f..027a03f 100644 --- a/lib/ratelimit.c +++ b/lib/ratelimit.c @@ -40,7 +40,7 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func) * the entity that is holding the lock already: */ if (!spin_trylock_irqsave(&rs->lock, flags)) - return 1; + return 0; if (!rs->begin) rs->begin = jiffies; -- cgit v1.1 From 3eac4abaa69949af0e2f64e5c55ee8a22bbdd3e7 Mon Sep 17 00:00:00 2001 From: Kevin Hilman Date: Wed, 7 Apr 2010 11:52:46 -0700 Subject: rwsem generic spinlock: use IRQ save/restore spinlocks rwsems can be used with IRQs disabled, particularily in early boot before IRQs are enabled. Currently the spin_unlock_irq() usage in the slow-patch will unconditionally enable interrupts and cause problems since interrupts are not yet initialized or enabled. This patch uses save/restore versions of IRQ spinlocks in the slowpath to ensure interrupts are not unintentionally disabled. Signed-off-by: Kevin Hilman Signed-off-by: Linus Torvalds --- lib/rwsem-spinlock.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c index ccf95bf..ffc9fc7 100644 --- a/lib/rwsem-spinlock.c +++ b/lib/rwsem-spinlock.c @@ -143,13 +143,14 @@ void __sched __down_read(struct rw_semaphore *sem) { struct rwsem_waiter waiter; struct task_struct *tsk; + unsigned long flags; - spin_lock_irq(&sem->wait_lock); + spin_lock_irqsave(&sem->wait_lock, flags); if (sem->activity >= 0 && list_empty(&sem->wait_list)) { /* granted */ sem->activity++; - spin_unlock_irq(&sem->wait_lock); + spin_unlock_irqrestore(&sem->wait_lock, flags); goto out; } @@ -164,7 +165,7 @@ void __sched __down_read(struct rw_semaphore *sem) list_add_tail(&waiter.list, &sem->wait_list); /* we don't need to touch the semaphore struct anymore */ - spin_unlock_irq(&sem->wait_lock); + spin_unlock_irqrestore(&sem->wait_lock, flags); /* wait to be given the lock */ for (;;) { @@ -209,13 +210,14 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass) { struct rwsem_waiter waiter; struct task_struct *tsk; + unsigned long flags; - spin_lock_irq(&sem->wait_lock); + spin_lock_irqsave(&sem->wait_lock, flags); if (sem->activity == 0 && list_empty(&sem->wait_list)) { /* granted */ sem->activity = -1; - spin_unlock_irq(&sem->wait_lock); + spin_unlock_irqrestore(&sem->wait_lock, flags); goto out; } @@ -230,7 +232,7 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass) list_add_tail(&waiter.list, &sem->wait_list); /* we don't need to touch the semaphore struct anymore */ - spin_unlock_irq(&sem->wait_lock); + spin_unlock_irqrestore(&sem->wait_lock, flags); /* wait to be given the lock */ for (;;) { -- cgit v1.1 From ce82653d6cfcc95ba88c25908664878459fb1b8d Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 6 Apr 2010 22:36:20 +0100 Subject: radix_tree_tag_get() is not as safe as the docs make out [ver #2] radix_tree_tag_get() is not safe to use concurrently with radix_tree_tag_set() or radix_tree_tag_clear(). The problem is that the double tag_get() in radix_tree_tag_get(): if (!tag_get(node, tag, offset)) saw_unset_tag = 1; if (height == 1) { int ret = tag_get(node, tag, offset); may see the value change due to the action of set/clear. RCU is no protection against this as no pointers are being changed, no nodes are being replaced according to a COW protocol - set/clear alter the node directly. The documentation in linux/radix-tree.h, however, says that radix_tree_tag_get() is an exception to the rule that "any function modifying the tree or tags (...) must exclude other modifications, and exclude any functions reading the tree". The problem is that the next statement in radix_tree_tag_get() checks that the tag doesn't vary over time: BUG_ON(ret && saw_unset_tag); This has been seen happening in FS-Cache: https://www.redhat.com/archives/linux-cachefs/2010-April/msg00013.html To this end, remove the BUG_ON() from radix_tree_tag_get() and note in various comments that the value of the tag may change whilst the RCU read lock is held, and thus that the return value of radix_tree_tag_get() may not be relied upon unless radix_tree_tag_set/clear() and radix_tree_delete() are excluded from running concurrently with it. Reported-by: Romain DEGEZ Signed-off-by: David Howells Acked-by: Nick Piggin Signed-off-by: Linus Torvalds --- lib/radix-tree.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 0871582..2a087e0 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -555,6 +555,10 @@ EXPORT_SYMBOL(radix_tree_tag_clear); * * 0: tag not present or not set * 1: tag set + * + * Note that the return value of this function may not be relied on, even if + * the RCU lock is held, unless tag modification and node deletion are excluded + * from concurrency. */ int radix_tree_tag_get(struct radix_tree_root *root, unsigned long index, unsigned int tag) @@ -595,12 +599,8 @@ int radix_tree_tag_get(struct radix_tree_root *root, */ if (!tag_get(node, tag, offset)) saw_unset_tag = 1; - if (height == 1) { - int ret = tag_get(node, tag, offset); - - BUG_ON(ret && saw_unset_tag); - return !!ret; - } + if (height == 1) + return !!tag_get(node, tag, offset); node = rcu_dereference_raw(node->slots[offset]); shift -= RADIX_TREE_MAP_SHIFT; height--; -- cgit v1.1