introduce variants of pipe_lock/pipe_unlock for real pipes/FIFOs

fs/pipe.c file_operations methods *know* that pipe is not an internal one;
no need to check pipe->inode for those callers.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2013-03-21 12:24:01 -04:00
parent de32ec4cfe
commit ebec73f475

View file

@ -75,6 +75,16 @@ void pipe_unlock(struct pipe_inode_info *pipe)
}
EXPORT_SYMBOL(pipe_unlock);
static inline void __pipe_lock(struct pipe_inode_info *pipe)
{
mutex_lock_nested(&pipe->mutex, I_MUTEX_PARENT);
}
static inline void __pipe_unlock(struct pipe_inode_info *pipe)
{
mutex_unlock(&pipe->mutex);
}
void pipe_double_lock(struct pipe_inode_info *pipe1,
struct pipe_inode_info *pipe2)
{
@ -376,7 +386,7 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov,
do_wakeup = 0;
ret = 0;
pipe_lock(pipe);
__pipe_lock(pipe);
for (;;) {
int bufs = pipe->nrbufs;
if (bufs) {
@ -464,7 +474,7 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov,
}
pipe_wait(pipe);
}
pipe_unlock(pipe);
__pipe_unlock(pipe);
/* Signal writers asynchronously that there is more room. */
if (do_wakeup) {
@ -500,7 +510,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov,
do_wakeup = 0;
ret = 0;
pipe_lock(pipe);
__pipe_lock(pipe);
if (!pipe->readers) {
send_sig(SIGPIPE, current, 0);
@ -647,7 +657,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov,
pipe->waiting_writers--;
}
out:
pipe_unlock(pipe);
__pipe_unlock(pipe);
if (do_wakeup) {
wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM);
kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
@ -667,7 +677,7 @@ static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
switch (cmd) {
case FIONREAD:
pipe_lock(pipe);
__pipe_lock(pipe);
count = 0;
buf = pipe->curbuf;
nrbufs = pipe->nrbufs;
@ -675,7 +685,7 @@ static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
count += pipe->bufs[buf].len;
buf = (buf+1) & (pipe->buffers - 1);
}
pipe_unlock(pipe);
__pipe_unlock(pipe);
return put_user(count, (int __user *)arg);
default:
@ -721,7 +731,7 @@ pipe_release(struct inode *inode, struct file *file)
struct pipe_inode_info *pipe = inode->i_pipe;
int kill = 0;
pipe_lock(pipe);
__pipe_lock(pipe);
if (file->f_mode & FMODE_READ)
pipe->readers--;
if (file->f_mode & FMODE_WRITE)
@ -738,7 +748,7 @@ pipe_release(struct inode *inode, struct file *file)
kill = 1;
}
spin_unlock(&inode->i_lock);
pipe_unlock(pipe);
__pipe_unlock(pipe);
if (kill)
__free_pipe_info(pipe);
@ -752,7 +762,7 @@ pipe_fasync(int fd, struct file *filp, int on)
struct pipe_inode_info *pipe = filp->private_data;
int retval = 0;
pipe_lock(pipe);
__pipe_lock(pipe);
if (filp->f_mode & FMODE_READ)
retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);
if ((filp->f_mode & FMODE_WRITE) && retval >= 0) {
@ -761,7 +771,7 @@ pipe_fasync(int fd, struct file *filp, int on)
/* this can happen only if on == T */
fasync_helper(-1, filp, 0, &pipe->fasync_readers);
}
pipe_unlock(pipe);
__pipe_unlock(pipe);
return retval;
}
@ -1040,7 +1050,7 @@ static int fifo_open(struct inode *inode, struct file *filp)
filp->private_data = pipe;
/* OK, we have a pipe and it's pinned down */
pipe_lock(pipe);
__pipe_lock(pipe);
/* We can only do regular read/write on fifos */
filp->f_mode &= (FMODE_READ | FMODE_WRITE);
@ -1110,7 +1120,7 @@ static int fifo_open(struct inode *inode, struct file *filp)
}
/* Ok! */
pipe_unlock(pipe);
__pipe_unlock(pipe);
return 0;
err_rd:
@ -1132,7 +1142,7 @@ static int fifo_open(struct inode *inode, struct file *filp)
kill = 1;
}
spin_unlock(&inode->i_lock);
pipe_unlock(pipe);
__pipe_unlock(pipe);
if (kill)
__free_pipe_info(pipe);
return ret;
@ -1248,7 +1258,7 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
if (!pipe)
return -EBADF;
pipe_lock(pipe);
__pipe_lock(pipe);
switch (cmd) {
case F_SETPIPE_SZ: {
@ -1277,7 +1287,7 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
}
out:
pipe_unlock(pipe);
__pipe_unlock(pipe);
return ret;
}