| Message ID | 20220717043532.35821-2-kuniyu@amazon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs/lock: Cleanup around flock syscall. | expand |
> On Jul 17, 2022, at 12:35 AM, Kuniyuki Iwashima <kuniyu@amazon.com> wrote: > > Two functions, flock syscall and locks_remove_flock(), call > flock_make_lock(). It allocates struct file_lock from slab > cache if its argument fl is NULL. > > When we call flock syscall, we pass NULL to allocate memory > for struct file_lock. However, we always free it at the end > by locks_free_lock(). We need not allocate it and instead > should use a local variable as locks_remove_flock() does. > > Also, the validation for flock_translate_cmd() is not necessary > for locks_remove_flock(). So we move the part to flock syscall > and make flock_make_lock() return nothing. > > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> > Reviewed-by: Chuck Lever <chuck.lever@oracle.com> v3 Reviewed-by: Chuck Lever <chuck.lever@oracle.com> > --- > fs/locks.c | 46 +++++++++++++++------------------------------- > 1 file changed, 15 insertions(+), 31 deletions(-) > > diff --git a/fs/locks.c b/fs/locks.c > index ca28e0e50e56..b134eaefd7d6 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -425,21 +425,9 @@ static inline int flock_translate_cmd(int cmd) { > } > > /* Fill in a file_lock structure with an appropriate FLOCK lock. */ > -static struct file_lock * > -flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl) > +static void flock_make_lock(struct file *filp, struct file_lock *fl, int type) > { > - int type = flock_translate_cmd(cmd); > - > - if (type < 0) > - return ERR_PTR(type); > - > - if (fl == NULL) { > - fl = locks_alloc_lock(); > - if (fl == NULL) > - return ERR_PTR(-ENOMEM); > - } else { > - locks_init_lock(fl); > - } > + locks_init_lock(fl); > > fl->fl_file = filp; > fl->fl_owner = filp; > @@ -447,8 +435,6 @@ flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl) > fl->fl_flags = FL_FLOCK; > fl->fl_type = type; > fl->fl_end = OFFSET_MAX; > - > - return fl; > } > > static int assign_type(struct file_lock *fl, long type) > @@ -2097,10 +2083,9 @@ EXPORT_SYMBOL(locks_lock_inode_wait); > */ > SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) > { > + int can_sleep, error, unlock, type; > struct fd f = fdget(fd); > - struct file_lock *lock; > - int can_sleep, unlock; > - int error; > + struct file_lock fl; > > error = -EBADF; > if (!f.file) > @@ -2127,28 +2112,27 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) > goto out_putf; > } > > - lock = flock_make_lock(f.file, cmd, NULL); > - if (IS_ERR(lock)) { > - error = PTR_ERR(lock); > + type = flock_translate_cmd(cmd); > + if (type < 0) { > + error = type; > goto out_putf; > } > > + flock_make_lock(f.file, &fl, type); > + > if (can_sleep) > - lock->fl_flags |= FL_SLEEP; > + fl.fl_flags |= FL_SLEEP; > > - error = security_file_lock(f.file, lock->fl_type); > + error = security_file_lock(f.file, fl.fl_type); > if (error) > - goto out_free; > + goto out_putf; > > if (f.file->f_op->flock) > error = f.file->f_op->flock(f.file, > (can_sleep) ? F_SETLKW : F_SETLK, > - lock); > + &fl); > else > - error = locks_lock_file_wait(f.file, lock); > - > - out_free: > - locks_free_lock(lock); > + error = locks_lock_file_wait(f.file, &fl); > > out_putf: > fdput(f); > @@ -2614,7 +2598,7 @@ locks_remove_flock(struct file *filp, struct file_lock_context *flctx) > if (list_empty(&flctx->flc_flock)) > return; > > - flock_make_lock(filp, LOCK_UN, &fl); > + flock_make_lock(filp, &fl, F_UNLCK); > fl.fl_flags |= FL_CLOSE; > > if (filp->f_op->flock) > -- > 2.30.2 > -- Chuck Lever
diff --git a/fs/locks.c b/fs/locks.c index ca28e0e50e56..b134eaefd7d6 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -425,21 +425,9 @@ static inline int flock_translate_cmd(int cmd) { } /* Fill in a file_lock structure with an appropriate FLOCK lock. */ -static struct file_lock * -flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl) +static void flock_make_lock(struct file *filp, struct file_lock *fl, int type) { - int type = flock_translate_cmd(cmd); - - if (type < 0) - return ERR_PTR(type); - - if (fl == NULL) { - fl = locks_alloc_lock(); - if (fl == NULL) - return ERR_PTR(-ENOMEM); - } else { - locks_init_lock(fl); - } + locks_init_lock(fl); fl->fl_file = filp; fl->fl_owner = filp; @@ -447,8 +435,6 @@ flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl) fl->fl_flags = FL_FLOCK; fl->fl_type = type; fl->fl_end = OFFSET_MAX; - - return fl; } static int assign_type(struct file_lock *fl, long type) @@ -2097,10 +2083,9 @@ EXPORT_SYMBOL(locks_lock_inode_wait); */ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) { + int can_sleep, error, unlock, type; struct fd f = fdget(fd); - struct file_lock *lock; - int can_sleep, unlock; - int error; + struct file_lock fl; error = -EBADF; if (!f.file) @@ -2127,28 +2112,27 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) goto out_putf; } - lock = flock_make_lock(f.file, cmd, NULL); - if (IS_ERR(lock)) { - error = PTR_ERR(lock); + type = flock_translate_cmd(cmd); + if (type < 0) { + error = type; goto out_putf; } + flock_make_lock(f.file, &fl, type); + if (can_sleep) - lock->fl_flags |= FL_SLEEP; + fl.fl_flags |= FL_SLEEP; - error = security_file_lock(f.file, lock->fl_type); + error = security_file_lock(f.file, fl.fl_type); if (error) - goto out_free; + goto out_putf; if (f.file->f_op->flock) error = f.file->f_op->flock(f.file, (can_sleep) ? F_SETLKW : F_SETLK, - lock); + &fl); else - error = locks_lock_file_wait(f.file, lock); - - out_free: - locks_free_lock(lock); + error = locks_lock_file_wait(f.file, &fl); out_putf: fdput(f); @@ -2614,7 +2598,7 @@ locks_remove_flock(struct file *filp, struct file_lock_context *flctx) if (list_empty(&flctx->flc_flock)) return; - flock_make_lock(filp, LOCK_UN, &fl); + flock_make_lock(filp, &fl, F_UNLCK); fl.fl_flags |= FL_CLOSE; if (filp->f_op->flock)