diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2013-03-21 02:16:30 -0400 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2013-04-09 14:12:59 -0400 |
commit | 18c03cfd403b88852f75f200206983ee6df28423 (patch) | |
tree | 97ed126248046cbd3ec0c17f7cac3a8a0071704d | |
parent | fc7478a2bfa9abd19657d2bbc9ae24185a41e21b (diff) |
pipe: preparation to new locking rules
* use the fact that file_inode(file)->i_pipe doesn't change
while the file is opened - no locks needed to access that.
* switch to pipe_lock/pipe_unlock where it's easy to do
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r-- | fs/pipe.c | 38 |
1 files changed, 15 insertions, 23 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 105b0021b07..357471db890 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -363,8 +363,7 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov, unsigned long nr_segs, loff_t pos) { struct file *filp = iocb->ki_filp; - struct inode *inode = file_inode(filp); - struct pipe_inode_info *pipe; + struct pipe_inode_info *pipe = file_inode(filp)->i_pipe; int do_wakeup; ssize_t ret; struct iovec *iov = (struct iovec *)_iov; @@ -377,8 +376,7 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov, do_wakeup = 0; ret = 0; - mutex_lock(&inode->i_mutex); - pipe = inode->i_pipe; + pipe_lock(pipe); for (;;) { int bufs = pipe->nrbufs; if (bufs) { @@ -466,7 +464,7 @@ redo: } pipe_wait(pipe); } - mutex_unlock(&inode->i_mutex); + pipe_unlock(pipe); /* Signal writers asynchronously that there is more room. */ if (do_wakeup) { @@ -488,8 +486,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov, unsigned long nr_segs, loff_t ppos) { struct file *filp = iocb->ki_filp; - struct inode *inode = file_inode(filp); - struct pipe_inode_info *pipe; + struct pipe_inode_info *pipe = file_inode(filp)->i_pipe; ssize_t ret; int do_wakeup; struct iovec *iov = (struct iovec *)_iov; @@ -503,8 +500,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov, do_wakeup = 0; ret = 0; - mutex_lock(&inode->i_mutex); - pipe = inode->i_pipe; + pipe_lock(pipe); if (!pipe->readers) { send_sig(SIGPIPE, current, 0); @@ -651,7 +647,7 @@ redo2: pipe->waiting_writers--; } out: - mutex_unlock(&inode->i_mutex); + pipe_unlock(pipe); if (do_wakeup) { wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); @@ -666,14 +662,12 @@ out: static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { - struct inode *inode = file_inode(filp); - struct pipe_inode_info *pipe; + struct pipe_inode_info *pipe = file_inode(filp)->i_pipe; int count, buf, nrbufs; switch (cmd) { case FIONREAD: - mutex_lock(&inode->i_mutex); - pipe = inode->i_pipe; + pipe_lock(pipe); count = 0; buf = pipe->curbuf; nrbufs = pipe->nrbufs; @@ -681,7 +675,7 @@ static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) count += pipe->bufs[buf].len; buf = (buf+1) & (pipe->buffers - 1); } - mutex_unlock(&inode->i_mutex); + pipe_unlock(pipe); return put_user(count, (int __user *)arg); default: @@ -694,8 +688,7 @@ static unsigned int pipe_poll(struct file *filp, poll_table *wait) { unsigned int mask; - struct inode *inode = file_inode(filp); - struct pipe_inode_info *pipe = inode->i_pipe; + struct pipe_inode_info *pipe = file_inode(filp)->i_pipe; int nrbufs; poll_wait(filp, &pipe->wait, wait); @@ -749,11 +742,10 @@ pipe_release(struct inode *inode, struct file *file) static int pipe_fasync(int fd, struct file *filp, int on) { - struct inode *inode = file_inode(filp); - struct pipe_inode_info *pipe = inode->i_pipe; + struct pipe_inode_info *pipe = file_inode(filp)->i_pipe; int retval = 0; - mutex_lock(&inode->i_mutex); + 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) { @@ -762,7 +754,7 @@ pipe_fasync(int fd, struct file *filp, int on) /* this can happen only if on == T */ fasync_helper(-1, filp, 0, &pipe->fasync_readers); } - mutex_unlock(&inode->i_mutex); + pipe_unlock(pipe); return retval; } @@ -1224,7 +1216,7 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) if (!pipe) return -EBADF; - mutex_lock(&pipe->inode->i_mutex); + pipe_lock(pipe); switch (cmd) { case F_SETPIPE_SZ: { @@ -1253,7 +1245,7 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) } out: - mutex_unlock(&pipe->inode->i_mutex); + pipe_unlock(pipe); return ret; } |