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fs/lock: Rearrange ops in flock syscall. 

The previous patch added flock_translate_cmd() in flock syscall.
The test and the other one for LOCK_MAND do not depend on struct
fd and are cheaper, so we can put them at the top and defer
fdget() after that.

Also, we can remove the unlock variable and use type instead.
While at it, we fix this checkpatch error.

  CHECK: spaces preferred around that '|' (ctx:VxV)
  #45: FILE: fs/locks.c:2099:
  +	if (type != F_UNLCK && !(f.file->f_mode & (FMODE_READ|FMODE_WRITE)))
   	                                                     ^

Finally, we can move the can_sleep part just before we use it.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
This commit is contained in:
Kuniyuki Iwashima 2022-07-16 21:35:32 -07:00 committed by Jeff Layton
parent 4149be7bda
commit db4abb4a32
1 changed files with 19 additions and 24 deletions
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43
fs/locks.c
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@ -2083,20 +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);
int can_sleep, error, type;
struct file_lock fl;
error = -EBADF;
if (!f.file)
goto out;
can_sleep = !(cmd & LOCK_NB);
cmd &= ~LOCK_NB;
unlock = (cmd == LOCK_UN);
if (!unlock && !(f.file->f_mode & (FMODE_READ|FMODE_WRITE)))
goto out_putf;
struct fd f;
/*
* LOCK_MAND locks were broken for a long time in that they never
@ -2108,35 +2097,41 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
*/
if (cmd & LOCK_MAND) {
pr_warn_once("Attempt to set a LOCK_MAND lock via flock(2). This support has been removed and the request ignored.\n");
error = 0;
goto out_putf;
return 0;
}
type = flock_translate_cmd(cmd);
if (type < 0) {
error = type;
type = flock_translate_cmd(cmd & ~LOCK_NB);
if (type < 0)
return type;
error = -EBADF;
f = fdget(fd);
if (!f.file)
return error;
if (type != F_UNLCK && !(f.file->f_mode & (FMODE_READ | FMODE_WRITE)))
goto out_putf;
}
flock_make_lock(f.file, &fl, type);
if (can_sleep)
fl.fl_flags |= FL_SLEEP;
error = security_file_lock(f.file, fl.fl_type);
if (error)
goto out_putf;
can_sleep = !(cmd & LOCK_NB);
if (can_sleep)
fl.fl_flags |= FL_SLEEP;
if (f.file->f_op->flock)
error = f.file->f_op->flock(f.file,
(can_sleep) ? F_SETLKW : F_SETLK,
(can_sleep) ? F_SETLKW : F_SETLK,
&fl);
else
error = locks_lock_file_wait(f.file, &fl);
out_putf:
fdput(f);
out:
return error;
}