This reduces the slowdown in face of multiple callers issuing close on what turns out to not be the last reference. Signed-off-by: Mateusz Guzik <mjguzik@xxxxxxxxx> Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> Closes: https://lore.kernel.org/oe-lkp/202504171513.6d6f8a16-lkp@xxxxxxxxx --- fs/file.c | 2 +- include/linux/file_ref.h | 19 ++++++------------- 2 files changed, 7 insertions(+), 14 deletions(-) diff --git a/fs/file.c b/fs/file.c index dc3f7e120e3e..3a3146664cf3 100644 --- a/fs/file.c +++ b/fs/file.c @@ -26,7 +26,7 @@ #include "internal.h" -bool __file_ref_put_badval(file_ref_t *ref, unsigned long cnt) +static noinline bool __file_ref_put_badval(file_ref_t *ref, unsigned long cnt) { /* * If the reference count was already in the dead zone, then this diff --git a/include/linux/file_ref.h b/include/linux/file_ref.h index 7db62fbc0500..0f25ba769f48 100644 --- a/include/linux/file_ref.h +++ b/include/linux/file_ref.h @@ -61,7 +61,6 @@ static inline void file_ref_init(file_ref_t *ref, unsigned long cnt) atomic_long_set(&ref->refcnt, cnt - 1); } -bool __file_ref_put_badval(file_ref_t *ref, unsigned long cnt); bool __file_ref_put(file_ref_t *ref, unsigned long cnt); /** @@ -178,20 +177,14 @@ static __always_inline __must_check bool file_ref_put(file_ref_t *ref) */ static __always_inline __must_check bool file_ref_put_close(file_ref_t *ref) { - long old, new; + long old; old = atomic_long_read(&ref->refcnt); - do { - if (unlikely(old < 0)) - return __file_ref_put_badval(ref, old); - - if (old == FILE_REF_ONEREF) - new = FILE_REF_DEAD; - else - new = old - 1; - } while (!atomic_long_try_cmpxchg(&ref->refcnt, &old, new)); - - return new == FILE_REF_DEAD; + if (likely(old == FILE_REF_ONEREF)) { + if (likely(!atomic_long_try_cmpxchg(&ref->refcnt, &old, FILE_REF_DEAD))) + return true; + } + return file_ref_put(ref); } /** -- 2.48.1
