#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/audit.h>
+#include <linux/syscalls.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
* -- Manfred Spraul <manfred@colorfullife.com> 2002-05-09
*/
+static void pipe_lock_nested(struct pipe_inode_info *pipe, int subclass)
+{
+ if (pipe->inode)
+ mutex_lock_nested(&pipe->inode->i_mutex, subclass);
+}
+
+void pipe_lock(struct pipe_inode_info *pipe)
+{
+ /*
+ * pipe_lock() nests non-pipe inode locks (for writing to a file)
+ */
+ pipe_lock_nested(pipe, I_MUTEX_PARENT);
+}
+EXPORT_SYMBOL(pipe_lock);
+
+void pipe_unlock(struct pipe_inode_info *pipe)
+{
+ if (pipe->inode)
+ mutex_unlock(&pipe->inode->i_mutex);
+}
+EXPORT_SYMBOL(pipe_unlock);
+
+void pipe_double_lock(struct pipe_inode_info *pipe1,
+ struct pipe_inode_info *pipe2)
+{
+ BUG_ON(pipe1 == pipe2);
+
+ if (pipe1 < pipe2) {
+ pipe_lock_nested(pipe1, I_MUTEX_PARENT);
+ pipe_lock_nested(pipe2, I_MUTEX_CHILD);
+ } else {
+ pipe_lock_nested(pipe2, I_MUTEX_PARENT);
+ pipe_lock_nested(pipe1, I_MUTEX_CHILD);
+ }
+}
+
/* Drop the inode semaphore and wait for a pipe event, atomically */
void pipe_wait(struct pipe_inode_info *pipe)
{
* is considered a noninteractive wait:
*/
prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE);
- if (pipe->inode)
- mutex_unlock(&pipe->inode->i_mutex);
+ pipe_unlock(pipe);
schedule();
finish_wait(&pipe->wait, &wait);
- if (pipe->inode)
- mutex_lock(&pipe->inode->i_mutex);
+ pipe_lock(pipe);
}
static int
return 0;
}
+/**
+ * generic_pipe_buf_release - put a reference to a &struct pipe_buffer
+ * @pipe: the pipe that the buffer belongs to
+ * @buf: the buffer to put a reference to
+ *
+ * Description:
+ * This function releases a reference to @buf.
+ */
+void generic_pipe_buf_release(struct pipe_inode_info *pipe,
+ struct pipe_buffer *buf)
+{
+ page_cache_release(buf->page);
+}
+
static const struct pipe_buf_operations anon_pipe_buf_ops = {
.can_merge = 1,
.map = generic_pipe_buf_map,
retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers);
mutex_unlock(&inode->i_mutex);
- if (retval < 0)
- return retval;
-
- return 0;
+ return retval;
}
retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers);
mutex_unlock(&inode->i_mutex);
- if (retval < 0)
- return retval;
-
- return 0;
+ return retval;
}
int retval;
mutex_lock(&inode->i_mutex);
-
retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);
-
- if (retval >= 0)
+ if (retval >= 0) {
retval = fasync_helper(fd, filp, on, &pipe->fasync_writers);
-
+ if (retval < 0) /* this can happen only if on == T */
+ fasync_helper(-1, filp, 0, &pipe->fasync_readers);
+ }
mutex_unlock(&inode->i_mutex);
-
- if (retval < 0)
- return retval;
-
- return 0;
+ return retval;
}
static int
pipe_read_release(struct inode *inode, struct file *filp)
{
- pipe_read_fasync(-1, filp, 0);
return pipe_release(inode, 1, 0);
}
static int
pipe_write_release(struct inode *inode, struct file *filp)
{
- pipe_write_fasync(-1, filp, 0);
return pipe_release(inode, 0, 1);
}
{
int decr, decw;
- pipe_rdwr_fasync(-1, filp, 0);
decr = (filp->f_mode & FMODE_READ) != 0;
decw = (filp->f_mode & FMODE_WRITE) != 0;
return pipe_release(inode, decr, decw);
static int
pipe_read_open(struct inode *inode, struct file *filp)
{
- /* We could have perhaps used atomic_t, but this and friends
- below are the only places. So it doesn't seem worthwhile. */
+ int ret = -ENOENT;
+
mutex_lock(&inode->i_mutex);
- inode->i_pipe->readers++;
+
+ if (inode->i_pipe) {
+ ret = 0;
+ inode->i_pipe->readers++;
+ }
+
mutex_unlock(&inode->i_mutex);
- return 0;
+ return ret;
}
static int
pipe_write_open(struct inode *inode, struct file *filp)
{
+ int ret = -ENOENT;
+
mutex_lock(&inode->i_mutex);
- inode->i_pipe->writers++;
+
+ if (inode->i_pipe) {
+ ret = 0;
+ inode->i_pipe->writers++;
+ }
+
mutex_unlock(&inode->i_mutex);
- return 0;
+ return ret;
}
static int
pipe_rdwr_open(struct inode *inode, struct file *filp)
{
+ int ret = -ENOENT;
+
mutex_lock(&inode->i_mutex);
- if (filp->f_mode & FMODE_READ)
- inode->i_pipe->readers++;
- if (filp->f_mode & FMODE_WRITE)
- inode->i_pipe->writers++;
+
+ if (inode->i_pipe) {
+ ret = 0;
+ if (filp->f_mode & FMODE_READ)
+ inode->i_pipe->readers++;
+ if (filp->f_mode & FMODE_WRITE)
+ inode->i_pipe->writers++;
+ }
+
mutex_unlock(&inode->i_mutex);
- return 0;
+ return ret;
}
/*
* The file_operations structs are not static because they
* are also used in linux/fs/fifo.c to do operations on FIFOs.
+ *
+ * Pipes reuse fifos' file_operations structs.
*/
-const struct file_operations read_fifo_fops = {
+const struct file_operations read_pipefifo_fops = {
.llseek = no_llseek,
.read = do_sync_read,
.aio_read = pipe_read,
.fasync = pipe_read_fasync,
};
-const struct file_operations write_fifo_fops = {
+const struct file_operations write_pipefifo_fops = {
.llseek = no_llseek,
.read = bad_pipe_r,
.write = do_sync_write,
.fasync = pipe_write_fasync,
};
-const struct file_operations rdwr_fifo_fops = {
- .llseek = no_llseek,
- .read = do_sync_read,
- .aio_read = pipe_read,
- .write = do_sync_write,
- .aio_write = pipe_write,
- .poll = pipe_poll,
- .unlocked_ioctl = pipe_ioctl,
- .open = pipe_rdwr_open,
- .release = pipe_rdwr_release,
- .fasync = pipe_rdwr_fasync,
-};
-
-static const struct file_operations read_pipe_fops = {
- .llseek = no_llseek,
- .read = do_sync_read,
- .aio_read = pipe_read,
- .write = bad_pipe_w,
- .poll = pipe_poll,
- .unlocked_ioctl = pipe_ioctl,
- .open = pipe_read_open,
- .release = pipe_read_release,
- .fasync = pipe_read_fasync,
-};
-
-static const struct file_operations write_pipe_fops = {
- .llseek = no_llseek,
- .read = bad_pipe_r,
- .write = do_sync_write,
- .aio_write = pipe_write,
- .poll = pipe_poll,
- .unlocked_ioctl = pipe_ioctl,
- .open = pipe_write_open,
- .release = pipe_write_release,
- .fasync = pipe_write_fasync,
-};
-
-static const struct file_operations rdwr_pipe_fops = {
+const struct file_operations rdwr_pipefifo_fops = {
.llseek = no_llseek,
.read = do_sync_read,
.aio_read = pipe_read,
dentry->d_inode->i_ino);
}
-static struct dentry_operations pipefs_dentry_operations = {
+static const struct dentry_operations pipefs_dentry_operations = {
.d_delete = pipefs_delete_dentry,
.d_dname = pipefs_dname,
};
inode->i_pipe = pipe;
pipe->readers = pipe->writers = 1;
- inode->i_fop = &rdwr_pipe_fops;
+ inode->i_fop = &rdwr_pipefifo_fops;
/*
* Mark the inode dirty from the very beginning,
*/
inode->i_state = I_DIRTY;
inode->i_mode = S_IFIFO | S_IRUSR | S_IWUSR;
- inode->i_uid = current->fsuid;
- inode->i_gid = current->fsgid;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
return inode;
return NULL;
}
-struct file *create_write_pipe(void)
+struct file *create_write_pipe(int flags)
{
int err;
struct inode *inode;
d_instantiate(dentry, inode);
err = -ENFILE;
- f = alloc_file(pipe_mnt, dentry, FMODE_WRITE, &write_pipe_fops);
+ f = alloc_file(pipe_mnt, dentry, FMODE_WRITE, &write_pipefifo_fops);
if (!f)
goto err_dentry;
f->f_mapping = inode->i_mapping;
- f->f_flags = O_WRONLY;
+ f->f_flags = O_WRONLY | (flags & O_NONBLOCK);
f->f_version = 0;
return f;
err_dentry:
+ free_pipe_info(inode);
dput(dentry);
+ return ERR_PTR(err);
+
err_inode:
free_pipe_info(inode);
iput(inode);
void free_write_pipe(struct file *f)
{
free_pipe_info(f->f_dentry->d_inode);
- dput(f->f_path.dentry);
- mntput(f->f_path.mnt);
+ path_put(&f->f_path);
put_filp(f);
}
-struct file *create_read_pipe(struct file *wrf)
+struct file *create_read_pipe(struct file *wrf, int flags)
{
struct file *f = get_empty_filp();
if (!f)
return ERR_PTR(-ENFILE);
/* Grab pipe from the writer */
- f->f_path.mnt = mntget(wrf->f_path.mnt);
- f->f_path.dentry = dget(wrf->f_path.dentry);
+ f->f_path = wrf->f_path;
+ path_get(&wrf->f_path);
f->f_mapping = wrf->f_path.dentry->d_inode->i_mapping;
f->f_pos = 0;
- f->f_flags = O_RDONLY;
- f->f_op = &read_pipe_fops;
+ f->f_flags = O_RDONLY | (flags & O_NONBLOCK);
+ f->f_op = &read_pipefifo_fops;
f->f_mode = FMODE_READ;
f->f_version = 0;
return f;
}
-int do_pipe(int *fd)
+int do_pipe_flags(int *fd, int flags)
{
struct file *fw, *fr;
int error;
int fdw, fdr;
- fw = create_write_pipe();
+ if (flags & ~(O_CLOEXEC | O_NONBLOCK))
+ return -EINVAL;
+
+ fw = create_write_pipe(flags);
if (IS_ERR(fw))
return PTR_ERR(fw);
- fr = create_read_pipe(fw);
+ fr = create_read_pipe(fw, flags);
error = PTR_ERR(fr);
if (IS_ERR(fr))
goto err_write_pipe;
- error = get_unused_fd();
+ error = get_unused_fd_flags(flags);
if (error < 0)
goto err_read_pipe;
fdr = error;
- error = get_unused_fd();
+ error = get_unused_fd_flags(flags);
if (error < 0)
goto err_fdr;
fdw = error;
- error = audit_fd_pair(fdr, fdw);
- if (error < 0)
- goto err_fdw;
-
+ audit_fd_pair(fdr, fdw);
fd_install(fdr, fr);
fd_install(fdw, fw);
fd[0] = fdr;
return 0;
- err_fdw:
- put_unused_fd(fdw);
err_fdr:
put_unused_fd(fdr);
err_read_pipe:
- dput(fr->f_dentry);
- mntput(fr->f_vfsmnt);
+ path_put(&fr->f_path);
put_filp(fr);
err_write_pipe:
free_write_pipe(fw);
}
/*
+ * sys_pipe() is the normal C calling standard for creating
+ * a pipe. It's not the way Unix traditionally does this, though.
+ */
+SYSCALL_DEFINE2(pipe2, int __user *, fildes, int, flags)
+{
+ int fd[2];
+ int error;
+
+ error = do_pipe_flags(fd, flags);
+ if (!error) {
+ if (copy_to_user(fildes, fd, sizeof(fd))) {
+ sys_close(fd[0]);
+ sys_close(fd[1]);
+ error = -EFAULT;
+ }
+ }
+ return error;
+}
+
+SYSCALL_DEFINE1(pipe, int __user *, fildes)
+{
+ return sys_pipe2(fildes, 0);
+}
+
+/*
* pipefs should _never_ be mounted by userland - too much of security hassle,
* no real gain from having the whole whorehouse mounted. So we don't need
* any operations on the root directory. However, we need a non-trivial
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff