From 06efa5f30c28eaf237247ca8c4cb46eb62cb6bd9 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sat, 22 Jun 2024 21:38:58 -0400 Subject: closures: closure_get_not_zero(), closure_return_sync() Provide new primitives for solving a lifetime issue with bcachefs btree_trans objects. closure_sync_return(): like closure_sync(), wait synchronously for any outstanding gets. like closure_return, the closure is considered "finished" and the ref left at 0. closure_get_not_zero(): get a ref on a closure if it's alive, i.e. the ref is not zero. Signed-off-by: Kent Overstreet --- lib/closure.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 46 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/closure.c b/lib/closure.c index 2e1ee9fdec08..c971216d9d77 100644 --- a/lib/closure.c +++ b/lib/closure.c @@ -13,7 +13,7 @@ #include #include -static inline void closure_put_after_sub(struct closure *cl, int flags) +static inline void closure_put_after_sub_checks(int flags) { int r = flags & CLOSURE_REMAINING_MASK; @@ -22,12 +22,17 @@ static inline void closure_put_after_sub(struct closure *cl, int flags) flags & CLOSURE_GUARD_MASK, (unsigned) __fls(r))) r &= ~CLOSURE_GUARD_MASK; - if (!r) { - smp_acquire__after_ctrl_dep(); + WARN(!r && (flags & ~CLOSURE_DESTRUCTOR), + "closure ref hit 0 with incorrect flags set: %x (%u)", + flags & ~CLOSURE_DESTRUCTOR, (unsigned) __fls(flags)); +} + +static inline void closure_put_after_sub(struct closure *cl, int flags) +{ + closure_put_after_sub_checks(flags); - WARN(flags & ~CLOSURE_DESTRUCTOR, - "closure ref hit 0 with incorrect flags set: %x (%u)", - flags & ~CLOSURE_DESTRUCTOR, (unsigned) __fls(flags)); + if (!(flags & CLOSURE_REMAINING_MASK)) { + smp_acquire__after_ctrl_dep(); cl->closure_get_happened = false; @@ -145,6 +150,41 @@ void __sched __closure_sync(struct closure *cl) } EXPORT_SYMBOL(__closure_sync); +/* + * closure_return_sync - finish running a closure, synchronously (i.e. waiting + * for outstanding get()s to finish) and returning once closure refcount is 0. + * + * Unlike closure_sync() this doesn't reinit the ref to 1; subsequent + * closure_get_not_zero() calls waill fail. + */ +void __sched closure_return_sync(struct closure *cl) +{ + struct closure_syncer s = { .task = current }; + + cl->s = &s; + set_closure_fn(cl, closure_sync_fn, NULL); + + unsigned flags = atomic_sub_return_release(1 + CLOSURE_RUNNING - CLOSURE_DESTRUCTOR, + &cl->remaining); + + closure_put_after_sub_checks(flags); + + if (unlikely(flags & CLOSURE_REMAINING_MASK)) { + while (1) { + set_current_state(TASK_UNINTERRUPTIBLE); + if (s.done) + break; + schedule(); + } + + __set_current_state(TASK_RUNNING); + } + + if (cl->parent) + closure_put(cl->parent); +} +EXPORT_SYMBOL(closure_return_sync); + int __sched __closure_sync_timeout(struct closure *cl, unsigned long timeout) { struct closure_syncer s = { .task = current }; -- cgit From 6a4805b2f51a2e5dc346651e0d0cd8abcc2937c8 Mon Sep 17 00:00:00 2001 From: Jeff Johnson Date: Fri, 31 May 2024 16:07:26 -0700 Subject: string: kunit: add missing MODULE_DESCRIPTION() macros make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in lib/string_kunit.o WARNING: modpost: missing MODULE_DESCRIPTION() in lib/string_helpers_kunit.o Add the missing invocation of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson Link: https://lore.kernel.org/r/20240531-md-lib-string-v1-1-2738cf057d94@quicinc.com Signed-off-by: Kees Cook --- lib/string_helpers_kunit.c | 1 + lib/string_kunit.c | 1 + 2 files changed, 2 insertions(+) (limited to 'lib') diff --git a/lib/string_helpers_kunit.c b/lib/string_helpers_kunit.c index f88e39fd68d6..c853046183d2 100644 --- a/lib/string_helpers_kunit.c +++ b/lib/string_helpers_kunit.c @@ -625,4 +625,5 @@ static struct kunit_suite string_helpers_test_suite = { kunit_test_suites(&string_helpers_test_suite); +MODULE_DESCRIPTION("Test cases for string helpers module"); MODULE_LICENSE("Dual BSD/GPL"); diff --git a/lib/string_kunit.c b/lib/string_kunit.c index 2a812decf14b..c919e3293da6 100644 --- a/lib/string_kunit.c +++ b/lib/string_kunit.c @@ -633,4 +633,5 @@ static struct kunit_suite string_test_suite = { kunit_test_suites(&string_test_suite); +MODULE_DESCRIPTION("Test cases for string functions"); MODULE_LICENSE("GPL v2"); -- cgit