Unverified Commit d1f7256a authored by Mateusz Guzik's avatar Mateusz Guzik Committed by Christian Brauner
Browse files

fs: fall back to file_ref_put() for non-last reference 



This reduces the slowdown in face of multiple callers issuing close on
what turns out to not be the last reference.

Signed-off-by: default avatarMateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/20250418125756.59677-1-mjguzik@gmail.com


Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reported-by: default avatarkernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202504171513.6d6f8a16-lkp@intel.com


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 53f7eedd

fs/file.c

+1 −1
Original line number Diff line number Diff line
@@ -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

include/linux/file_ref.h

+6 −13
Original line number Diff line number Diff line
@@ -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);

}



/**