# git rev-parse -q --verify b8d5109f50969ead9d49c3e8bd78ec1f82e548e3^{commit} b8d5109f50969ead9d49c3e8bd78ec1f82e548e3 already have revision, skipping fetch # git checkout -q -f -B kisskb b8d5109f50969ead9d49c3e8bd78ec1f82e548e3 # git clean -qxdf # < git log -1 # commit b8d5109f50969ead9d49c3e8bd78ec1f82e548e3 # Author: Linus Torvalds # Date: Sun Jul 3 14:40:28 2022 -0700 # # lockref: remove unused 'lockref_get_or_lock()' function # # Looking at the conditional lock acquire functions in the kernel due to # the new sparse support (see commit 4a557a5d1a61 "sparse: introduce # conditional lock acquire function attribute"), it became obvious that # the lockref code has a couple of them, but they don't match the usual # naming convention for the other ones, and their return value logic is # also reversed. # # In the other very similar places, the naming pattern is '*_and_lock()' # (eg 'atomic_put_and_lock()' and 'refcount_dec_and_lock()'), and the # function returns true when the lock is taken. # # The lockref code is superficially very similar to the refcount code, # only with the special "atomic wrt the embedded lock" semantics. But # instead of the '*_and_lock()' naming it uses '*_or_lock()'. # # And instead of returning true in case it took the lock, it returns true # if it *didn't* take the lock. # # Now, arguably the reflock code is quite logical: it really is a "either # decrement _or_ lock" kind of situation - and the return value is about # whether the operation succeeded without any special care needed. # # So despite the similarities, the differences do make some sense, and # maybe it's not worth trying to unify the different conditional locking # primitives in this area. # # But while looking at this all, it did become obvious that the # 'lockref_get_or_lock()' function hasn't actually had any users for # almost a decade. # # The only user it ever had was the shortlived 'd_rcu_to_refcount()' # function, and it got removed and replaced with 'lockref_get_not_dead()' # back in 2013 in commits 0d98439ea3c6 ("vfs: use lockred 'dead' flag to # mark unrecoverably dead dentries") and e5c832d55588 ("vfs: fix dentry # RCU to refcounting possibly sleeping dput()") # # In fact, that single use was removed less than a week after the whole # function was introduced in commit b3abd80250c1 ("lockref: add # 'lockref_get_or_lock() helper") so this function has been around for a # decade, but only had a user for six days. # # Let's just put this mis-designed and unused function out of its misery. # # We can think about the naming and semantic oddities of the remaining # 'lockref_put_or_lock()' later, but at least that function has users. # # And while the naming is different and the return value doesn't match, # that function matches the whole '{atomic,refcount}_dec_and_test()' # pattern much better (ie the magic happens when the count goes down to # zero, not when it is incremented from zero). # # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 b8d5109f50969ead9d49c3e8bd78ec1f82e548e3 # < make -s -j 40 ARCH=powerpc O=/kisskb/build/linus-rand_powerpc-randconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- randconfig # Added to kconfig CONFIG_STANDALONE=y # Added to kconfig CONFIG_BUILD_DOCSRC=n # Added to kconfig CONFIG_MODULE_SIG=n # Added to kconfig CONFIG_CPU_BIG_ENDIAN=y # Added to kconfig CONFIG_PPC64=y # Added to kconfig CONFIG_PPC_DISABLE_WERROR=y # Added to kconfig CONFIG_SECTION_MISMATCH_WARN_ONLY=y # Added to kconfig CONFIG_PREVENT_FIRMWARE_BUILD=y # Added to kconfig CONFIG_CC_STACKPROTECTOR_STRONG=n # Added to kconfig CONFIG_GCC_PLUGINS=n # Added to kconfig CONFIG_LD_HEAD_STUB_CATCH=y # Added to kconfig CONFIG_TRIM_UNUSED_KSYMS=n # Added to kconfig CONFIG_UBSAN=n # < make -s -j 40 ARCH=powerpc O=/kisskb/build/linus-rand_powerpc-randconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 40 ARCH=powerpc O=/kisskb/build/linus-rand_powerpc-randconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig .config:4641:warning: override: reassigning to symbol MODULE_SIG .config:4643:warning: override: reassigning to symbol PPC64 .config:4644:warning: override: reassigning to symbol PPC_DISABLE_WERROR .config:4645:warning: override: reassigning to symbol SECTION_MISMATCH_WARN_ONLY .config:4646:warning: override: reassigning to symbol PREVENT_FIRMWARE_BUILD .config:4648:warning: override: reassigning to symbol GCC_PLUGINS # make -s -j 40 ARCH=powerpc O=/kisskb/build/linus-rand_powerpc-randconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- In file included from /kisskb/src/arch/powerpc/include/asm/book3s/64/pgtable.h:312, from /kisskb/src/arch/powerpc/include/asm/book3s/64/mmu-hash.h:20, from /kisskb/src/arch/powerpc/include/asm/book3s/64/mmu.h:32, from /kisskb/src/arch/powerpc/include/asm/mmu.h:405, from /kisskb/src/arch/powerpc/include/asm/lppaca.h:46, from /kisskb/src/arch/powerpc/include/asm/paca.h:18, from /kisskb/src/arch/powerpc/include/asm/current.h:13, from /kisskb/src/include/linux/thread_info.h:23, from /kisskb/src/include/asm-generic/preempt.h:5, from ./arch/powerpc/include/generated/asm/preempt.h:1, from /kisskb/src/include/linux/preempt.h:78, from /kisskb/src/include/linux/spinlock.h:55, from /kisskb/src/include/linux/ipc.h:5, from /kisskb/src/include/uapi/linux/sem.h:5, from /kisskb/src/include/linux/sem.h:5, from /kisskb/src/include/linux/compat.h:14, from /kisskb/src/arch/powerpc/kernel/asm-offsets.c:12: /kisskb/src/arch/powerpc/include/asm/book3s/64/pgtable-64k.h: In function 'get_hugepd_cache_index': /kisskb/src/arch/powerpc/include/asm/book3s/64/pgtable-64k.h:60:1: error: no return statement in function returning non-void [-Werror=return-type] 60 | } | ^ cc1: some warnings being treated as errors make[2]: *** [/kisskb/src/scripts/Makefile.build:117: arch/powerpc/kernel/asm-offsets.s] Error 1 make[1]: *** [/kisskb/src/Makefile:1200: prepare0] Error 2 make: *** [Makefile:219: __sub-make] Error 2 Command 'make -s -j 40 ARCH=powerpc O=/kisskb/build/linus-rand_powerpc-randconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- ' returned non-zero exit status 2 # rm -rf /kisskb/build/linus-rand_powerpc-randconfig_powerpc-gcc11 # Build took: 0:00:14.017722