#include <linux/uio.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
+#include <linux/audit.h>
+#include <linux/syscalls.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
* Pipes are system-local resources, so sleeping on them
* is considered a noninteractive wait:
*/
- prepare_to_wait(&pipe->wait, &wait,
- TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE);
+ prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE);
if (pipe->inode)
mutex_unlock(&pipe->inode->i_mutex);
schedule();
page_cache_release(page);
}
+/**
+ * generic_pipe_buf_map - virtually map a pipe buffer
+ * @pipe: the pipe that the buffer belongs to
+ * @buf: the buffer that should be mapped
+ * @atomic: whether to use an atomic map
+ *
+ * Description:
+ * This function returns a kernel virtual address mapping for the
+ * pipe_buffer passed in @buf. If @atomic is set, an atomic map is provided
+ * and the caller has to be careful not to fault before calling
+ * the unmap function.
+ *
+ * Note that this function occupies KM_USER0 if @atomic != 0.
+ */
void *generic_pipe_buf_map(struct pipe_inode_info *pipe,
struct pipe_buffer *buf, int atomic)
{
return kmap(buf->page);
}
+/**
+ * generic_pipe_buf_unmap - unmap a previously mapped pipe buffer
+ * @pipe: the pipe that the buffer belongs to
+ * @buf: the buffer that should be unmapped
+ * @map_data: the data that the mapping function returned
+ *
+ * Description:
+ * This function undoes the mapping that ->map() provided.
+ */
void generic_pipe_buf_unmap(struct pipe_inode_info *pipe,
struct pipe_buffer *buf, void *map_data)
{
kunmap(buf->page);
}
+/**
+ * generic_pipe_buf_steal - attempt to take ownership of a &pipe_buffer
+ * @pipe: the pipe that the buffer belongs to
+ * @buf: the buffer to attempt to steal
+ *
+ * Description:
+ * This function attempts to steal the &struct page attached to
+ * @buf. If successful, this function returns 0 and returns with
+ * the page locked. The caller may then reuse the page for whatever
+ * he wishes; the typical use is insertion into a different file
+ * page cache.
+ */
int generic_pipe_buf_steal(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
struct page *page = buf->page;
+ /*
+ * A reference of one is golden, that means that the owner of this
+ * page is the only one holding a reference to it. lock the page
+ * and return OK.
+ */
if (page_count(page) == 1) {
lock_page(page);
return 0;
return 1;
}
-void generic_pipe_buf_get(struct pipe_inode_info *info, struct pipe_buffer *buf)
+/**
+ * generic_pipe_buf_get - get a reference to a &struct pipe_buffer
+ * @pipe: the pipe that the buffer belongs to
+ * @buf: the buffer to get a reference to
+ *
+ * Description:
+ * This function grabs an extra reference to @buf. It's used in
+ * in the tee() system call, when we duplicate the buffers in one
+ * pipe into another.
+ */
+void generic_pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
{
page_cache_get(buf->page);
}
-int generic_pipe_buf_pin(struct pipe_inode_info *info, struct pipe_buffer *buf)
+/**
+ * generic_pipe_buf_confirm - verify contents of the pipe buffer
+ * @info: the pipe that the buffer belongs to
+ * @buf: the buffer to confirm
+ *
+ * Description:
+ * This function does nothing, because the generic pipe code uses
+ * pages that are always good when inserted into the pipe.
+ */
+int generic_pipe_buf_confirm(struct pipe_inode_info *info,
+ struct pipe_buffer *buf)
{
return 0;
}
-static struct pipe_buf_operations anon_pipe_buf_ops = {
+static const struct pipe_buf_operations anon_pipe_buf_ops = {
.can_merge = 1,
.map = generic_pipe_buf_map,
.unmap = generic_pipe_buf_unmap,
- .pin = generic_pipe_buf_pin,
+ .confirm = generic_pipe_buf_confirm,
.release = anon_pipe_buf_release,
.steal = generic_pipe_buf_steal,
.get = generic_pipe_buf_get,
};
static ssize_t
-pipe_readv(struct file *filp, const struct iovec *_iov,
- unsigned long nr_segs, loff_t *ppos)
+pipe_read(struct kiocb *iocb, const struct iovec *_iov,
+ unsigned long nr_segs, loff_t pos)
{
- struct inode *inode = filp->f_dentry->d_inode;
+ struct file *filp = iocb->ki_filp;
+ struct inode *inode = filp->f_path.dentry->d_inode;
struct pipe_inode_info *pipe;
int do_wakeup;
ssize_t ret;
if (bufs) {
int curbuf = pipe->curbuf;
struct pipe_buffer *buf = pipe->bufs + curbuf;
- struct pipe_buf_operations *ops = buf->ops;
+ const struct pipe_buf_operations *ops = buf->ops;
void *addr;
size_t chars = buf->len;
int error, atomic;
if (chars > total_len)
chars = total_len;
- error = ops->pin(pipe, buf);
+ error = ops->confirm(pipe, buf);
if (error) {
if (!ret)
error = ret;
/* Signal writers asynchronously that there is more room. */
if (do_wakeup) {
- wake_up_interruptible(&pipe->wait);
+ wake_up_interruptible_sync(&pipe->wait);
kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
}
if (ret > 0)
}
static ssize_t
-pipe_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
+pipe_write(struct kiocb *iocb, const struct iovec *_iov,
+ unsigned long nr_segs, loff_t ppos)
{
- struct iovec iov = { .iov_base = buf, .iov_len = count };
-
- return pipe_readv(filp, &iov, 1, ppos);
-}
-
-static ssize_t
-pipe_writev(struct file *filp, const struct iovec *_iov,
- unsigned long nr_segs, loff_t *ppos)
-{
- struct inode *inode = filp->f_dentry->d_inode;
+ struct file *filp = iocb->ki_filp;
+ struct inode *inode = filp->f_path.dentry->d_inode;
struct pipe_inode_info *pipe;
ssize_t ret;
int do_wakeup;
int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) &
(PIPE_BUFFERS-1);
struct pipe_buffer *buf = pipe->bufs + lastbuf;
- struct pipe_buf_operations *ops = buf->ops;
+ const struct pipe_buf_operations *ops = buf->ops;
int offset = buf->offset + buf->len;
if (ops->can_merge && offset + chars <= PAGE_SIZE) {
int error, atomic = 1;
void *addr;
- error = ops->pin(pipe, buf);
+ error = ops->confirm(pipe, buf);
if (error)
goto out;
out:
mutex_unlock(&inode->i_mutex);
if (do_wakeup) {
- wake_up_interruptible(&pipe->wait);
+ wake_up_interruptible_sync(&pipe->wait);
kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
}
if (ret > 0)
}
static ssize_t
-pipe_write(struct file *filp, const char __user *buf,
- size_t count, loff_t *ppos)
-{
- struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
-
- return pipe_writev(filp, &iov, 1, ppos);
-}
-
-static ssize_t
bad_pipe_r(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
{
return -EBADF;
return -EBADF;
}
-static int
-pipe_ioctl(struct inode *pino, struct file *filp,
- unsigned int cmd, unsigned long arg)
+static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
- struct inode *inode = filp->f_dentry->d_inode;
+ struct inode *inode = filp->f_path.dentry->d_inode;
struct pipe_inode_info *pipe;
int count, buf, nrbufs;
pipe_poll(struct file *filp, poll_table *wait)
{
unsigned int mask;
- struct inode *inode = filp->f_dentry->d_inode;
+ struct inode *inode = filp->f_path.dentry->d_inode;
struct pipe_inode_info *pipe = inode->i_pipe;
int nrbufs;
if (!pipe->readers && !pipe->writers) {
free_pipe_info(inode);
} else {
- wake_up_interruptible(&pipe->wait);
+ wake_up_interruptible_sync(&pipe->wait);
kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
}
static int
pipe_read_fasync(int fd, struct file *filp, int on)
{
- struct inode *inode = filp->f_dentry->d_inode;
+ struct inode *inode = filp->f_path.dentry->d_inode;
int retval;
mutex_lock(&inode->i_mutex);
static int
pipe_write_fasync(int fd, struct file *filp, int on)
{
- struct inode *inode = filp->f_dentry->d_inode;
+ struct inode *inode = filp->f_path.dentry->d_inode;
int retval;
mutex_lock(&inode->i_mutex);
static int
pipe_rdwr_fasync(int fd, struct file *filp, int on)
{
- struct inode *inode = filp->f_dentry->d_inode;
+ struct inode *inode = filp->f_path.dentry->d_inode;
struct pipe_inode_info *pipe = inode->i_pipe;
int 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);
/*
* 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 = {
- .llseek = no_llseek,
- .read = pipe_read,
- .readv = pipe_readv,
- .write = bad_pipe_w,
- .poll = pipe_poll,
- .ioctl = pipe_ioctl,
- .open = pipe_read_open,
- .release = pipe_read_release,
- .fasync = pipe_read_fasync,
-};
-
-const struct file_operations write_fifo_fops = {
- .llseek = no_llseek,
- .read = bad_pipe_r,
- .write = pipe_write,
- .writev = pipe_writev,
- .poll = pipe_poll,
- .ioctl = pipe_ioctl,
- .open = pipe_write_open,
- .release = pipe_write_release,
- .fasync = pipe_write_fasync,
-};
-
-const struct file_operations rdwr_fifo_fops = {
+const struct file_operations read_pipefifo_fops = {
.llseek = no_llseek,
- .read = pipe_read,
- .readv = pipe_readv,
- .write = pipe_write,
- .writev = pipe_writev,
- .poll = pipe_poll,
- .ioctl = pipe_ioctl,
- .open = pipe_rdwr_open,
- .release = pipe_rdwr_release,
- .fasync = pipe_rdwr_fasync,
-};
-
-static struct file_operations read_pipe_fops = {
- .llseek = no_llseek,
- .read = pipe_read,
- .readv = pipe_readv,
+ .read = do_sync_read,
+ .aio_read = pipe_read,
.write = bad_pipe_w,
.poll = pipe_poll,
- .ioctl = pipe_ioctl,
+ .unlocked_ioctl = pipe_ioctl,
.open = pipe_read_open,
.release = pipe_read_release,
.fasync = pipe_read_fasync,
};
-static struct file_operations write_pipe_fops = {
+const struct file_operations write_pipefifo_fops = {
.llseek = no_llseek,
.read = bad_pipe_r,
- .write = pipe_write,
- .writev = pipe_writev,
+ .write = do_sync_write,
+ .aio_write = pipe_write,
.poll = pipe_poll,
- .ioctl = pipe_ioctl,
+ .unlocked_ioctl = pipe_ioctl,
.open = pipe_write_open,
.release = pipe_write_release,
.fasync = pipe_write_fasync,
};
-static struct file_operations rdwr_pipe_fops = {
+const struct file_operations rdwr_pipefifo_fops = {
.llseek = no_llseek,
- .read = pipe_read,
- .readv = pipe_readv,
- .write = pipe_write,
- .writev = pipe_writev,
+ .read = do_sync_read,
+ .aio_read = pipe_read,
+ .write = do_sync_write,
+ .aio_write = pipe_write,
.poll = pipe_poll,
- .ioctl = pipe_ioctl,
+ .unlocked_ioctl = pipe_ioctl,
.open = pipe_rdwr_open,
.release = pipe_rdwr_release,
.fasync = pipe_rdwr_fasync,
static struct vfsmount *pipe_mnt __read_mostly;
static int pipefs_delete_dentry(struct dentry *dentry)
{
- return 1;
+ /*
+ * At creation time, we pretended this dentry was hashed
+ * (by clearing DCACHE_UNHASHED bit in d_flags)
+ * At delete time, we restore the truth : not hashed.
+ * (so that dput() can proceed correctly)
+ */
+ dentry->d_flags |= DCACHE_UNHASHED;
+ return 0;
+}
+
+/*
+ * pipefs_dname() is called from d_path().
+ */
+static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen)
+{
+ return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]",
+ dentry->d_inode->i_ino);
}
static struct dentry_operations pipefs_dentry_operations = {
.d_delete = pipefs_delete_dentry,
+ .d_dname = pipefs_dname,
};
static struct inode * get_pipe_inode(void)
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;
- inode->i_blksize = PAGE_SIZE;
return inode;
return NULL;
}
-int do_pipe(int *fd)
+struct file *create_write_pipe(int flags)
{
- struct qstr this;
- char name[32];
+ int err;
+ struct inode *inode;
+ struct file *f;
struct dentry *dentry;
- struct inode * inode;
- struct file *f1, *f2;
- int error;
- int i, j;
-
- error = -ENFILE;
- f1 = get_empty_filp();
- if (!f1)
- goto no_files;
-
- f2 = get_empty_filp();
- if (!f2)
- goto close_f1;
+ struct qstr name = { .name = "" };
+ err = -ENFILE;
inode = get_pipe_inode();
if (!inode)
- goto close_f12;
+ goto err;
- error = get_unused_fd();
- if (error < 0)
- goto close_f12_inode;
- i = error;
-
- error = get_unused_fd();
- if (error < 0)
- goto close_f12_inode_i;
- j = error;
-
- error = -ENOMEM;
- sprintf(name, "[%lu]", inode->i_ino);
- this.name = name;
- this.len = strlen(name);
- this.hash = inode->i_ino; /* will go */
- dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &this);
+ err = -ENOMEM;
+ dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &name);
if (!dentry)
- goto close_f12_inode_i_j;
+ goto err_inode;
dentry->d_op = &pipefs_dentry_operations;
- d_add(dentry, inode);
- f1->f_vfsmnt = f2->f_vfsmnt = mntget(mntget(pipe_mnt));
- f1->f_dentry = f2->f_dentry = dget(dentry);
- f1->f_mapping = f2->f_mapping = inode->i_mapping;
-
- /* read file */
- f1->f_pos = f2->f_pos = 0;
- f1->f_flags = O_RDONLY;
- f1->f_op = &read_pipe_fops;
- f1->f_mode = FMODE_READ;
- f1->f_version = 0;
-
- /* write file */
- f2->f_flags = O_WRONLY;
- f2->f_op = &write_pipe_fops;
- f2->f_mode = FMODE_WRITE;
- f2->f_version = 0;
-
- fd_install(i, f1);
- fd_install(j, f2);
- fd[0] = i;
- fd[1] = j;
+ /*
+ * We dont want to publish this dentry into global dentry hash table.
+ * We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED
+ * This permits a working /proc/$pid/fd/XXX on pipes
+ */
+ dentry->d_flags &= ~DCACHE_UNHASHED;
+ d_instantiate(dentry, inode);
- return 0;
+ err = -ENFILE;
+ 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 | (flags & O_NONBLOCK);
+ f->f_version = 0;
-close_f12_inode_i_j:
- put_unused_fd(j);
-close_f12_inode_i:
- put_unused_fd(i);
-close_f12_inode:
+ return f;
+
+ err_dentry:
+ free_pipe_info(inode);
+ dput(dentry);
+ return ERR_PTR(err);
+
+ err_inode:
free_pipe_info(inode);
iput(inode);
-close_f12:
- put_filp(f2);
-close_f1:
- put_filp(f1);
-no_files:
- return error;
+ err:
+ return ERR_PTR(err);
+}
+
+void free_write_pipe(struct file *f)
+{
+ free_pipe_info(f->f_dentry->d_inode);
+ path_put(&f->f_path);
+ put_filp(f);
+}
+
+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 = 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 | (flags & O_NONBLOCK);
+ f->f_op = &read_pipefifo_fops;
+ f->f_mode = FMODE_READ;
+ f->f_version = 0;
+
+ return f;
+}
+
+int do_pipe_flags(int *fd, int flags)
+{
+ struct file *fw, *fr;
+ int error;
+ int fdw, fdr;
+
+ 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, flags);
+ error = PTR_ERR(fr);
+ if (IS_ERR(fr))
+ goto err_write_pipe;
+
+ error = get_unused_fd_flags(flags);
+ if (error < 0)
+ goto err_read_pipe;
+ fdr = error;
+
+ error = get_unused_fd_flags(flags);
+ if (error < 0)
+ goto err_fdr;
+ fdw = error;
+
+ audit_fd_pair(fdr, fdw);
+ fd_install(fdr, fr);
+ fd_install(fdw, fw);
+ fd[0] = fdr;
+ fd[1] = fdw;
+
+ return 0;
+
+ err_fdr:
+ put_unused_fd(fdr);
+ err_read_pipe:
+ path_put(&fr->f_path);
+ put_filp(fr);
+ err_write_pipe:
+ free_write_pipe(fw);
+ return error;
+}
+
+int do_pipe(int *fd)
+{
+ return do_pipe_flags(fd, 0);
+}
+
+/*
+ * 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);
}
/*