#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
+#include <linux/log2.h>
#include <linux/mount.h>
#include <linux/pipe_fs_i.h>
#include <linux/uio.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
+#include <linux/audit.h>
+#include <linux/syscalls.h>
+#include <linux/fcntl.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
/*
+ * The max size that a non-root user is allowed to grow the pipe. Can
+ * be set by root in /proc/sys/fs/pipe-max-size
+ */
+unsigned int pipe_max_size = 1048576;
+
+/*
+ * Minimum pipe size, as required by POSIX
+ */
+unsigned int pipe_min_size = PAGE_SIZE;
+
+/*
* We use a start+len construction, which provides full use of the
* allocated memory.
* -- Florian Coosmann (FGC)
* -- 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)
{
* Pipes are system-local resources, so sleeping on them
* is considered a noninteractive wait:
*/
- prepare_to_wait(&pipe->wait, &wait,
- TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE);
- if (pipe->inode)
- mutex_unlock(&pipe->inode->i_mutex);
+ prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE);
+ pipe_unlock(pipe);
schedule();
finish_wait(&pipe->wait, &wait);
- if (pipe->inode)
- mutex_lock(&pipe->inode->i_mutex);
+ pipe_lock(pipe);
}
static int
-pipe_iov_copy_from_user(void *to, struct iovec *iov, unsigned long len)
+pipe_iov_copy_from_user(void *to, struct iovec *iov, unsigned long len,
+ int atomic)
{
unsigned long copy;
iov++;
copy = min_t(unsigned long, len, iov->iov_len);
- if (copy_from_user(to, iov->iov_base, copy))
- return -EFAULT;
+ if (atomic) {
+ if (__copy_from_user_inatomic(to, iov->iov_base, copy))
+ return -EFAULT;
+ } else {
+ if (copy_from_user(to, iov->iov_base, copy))
+ return -EFAULT;
+ }
to += copy;
len -= copy;
iov->iov_base += copy;
}
static int
-pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len)
+pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len,
+ int atomic)
{
unsigned long copy;
iov++;
copy = min_t(unsigned long, len, iov->iov_len);
- if (copy_to_user(iov->iov_base, from, copy))
- return -EFAULT;
+ if (atomic) {
+ if (__copy_to_user_inatomic(iov->iov_base, from, copy))
+ return -EFAULT;
+ } else {
+ if (copy_to_user(iov->iov_base, from, copy))
+ return -EFAULT;
+ }
from += copy;
len -= copy;
iov->iov_base += copy;
return 0;
}
+/*
+ * Attempt to pre-fault in the user memory, so we can use atomic copies.
+ * Returns the number of bytes not faulted in.
+ */
+static int iov_fault_in_pages_write(struct iovec *iov, unsigned long len)
+{
+ while (!iov->iov_len)
+ iov++;
+
+ while (len > 0) {
+ unsigned long this_len;
+
+ this_len = min_t(unsigned long, len, iov->iov_len);
+ if (fault_in_pages_writeable(iov->iov_base, this_len))
+ break;
+
+ len -= this_len;
+ iov++;
+ }
+
+ return len;
+}
+
+/*
+ * Pre-fault in the user memory, so we can use atomic copies.
+ */
+static void iov_fault_in_pages_read(struct iovec *iov, unsigned long len)
+{
+ while (!iov->iov_len)
+ iov++;
+
+ while (len > 0) {
+ unsigned long this_len;
+
+ this_len = min_t(unsigned long, len, iov->iov_len);
+ fault_in_pages_readable(iov->iov_base, this_len);
+ len -= this_len;
+ iov++;
+ }
+}
+
static void anon_pipe_buf_release(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
struct page *page = buf->page;
- buf->flags &= ~PIPE_BUF_FLAG_STOLEN;
-
/*
* If nobody else uses this page, and we don't already have a
* temporary page, let's keep track of it as a one-deep
page_cache_release(page);
}
-static void * anon_pipe_buf_map(struct file *file, struct pipe_inode_info *pipe,
- struct pipe_buffer *buf)
+/**
+ * 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)
{
+ if (atomic) {
+ buf->flags |= PIPE_BUF_FLAG_ATOMIC;
+ return kmap_atomic(buf->page, KM_USER0);
+ }
+
return kmap(buf->page);
}
+EXPORT_SYMBOL(generic_pipe_buf_map);
+
+/**
+ * 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)
+{
+ if (buf->flags & PIPE_BUF_FLAG_ATOMIC) {
+ buf->flags &= ~PIPE_BUF_FLAG_ATOMIC;
+ kunmap_atomic(map_data, KM_USER0);
+ } else
+ kunmap(buf->page);
+}
+EXPORT_SYMBOL(generic_pipe_buf_unmap);
+
+/**
+ * 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;
+}
+EXPORT_SYMBOL(generic_pipe_buf_steal);
-static void anon_pipe_buf_unmap(struct pipe_inode_info *pipe,
- 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)
{
- kunmap(buf->page);
+ page_cache_get(buf->page);
}
+EXPORT_SYMBOL(generic_pipe_buf_get);
-static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,
- 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)
{
- buf->flags |= PIPE_BUF_FLAG_STOLEN;
return 0;
}
+EXPORT_SYMBOL(generic_pipe_buf_confirm);
-static void anon_pipe_buf_get(struct pipe_inode_info *info,
+/**
+ * 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_get(buf->page);
+ page_cache_release(buf->page);
}
+EXPORT_SYMBOL(generic_pipe_buf_release);
-static struct pipe_buf_operations anon_pipe_buf_ops = {
+static const struct pipe_buf_operations anon_pipe_buf_ops = {
.can_merge = 1,
- .map = anon_pipe_buf_map,
- .unmap = anon_pipe_buf_unmap,
+ .map = generic_pipe_buf_map,
+ .unmap = generic_pipe_buf_unmap,
+ .confirm = generic_pipe_buf_confirm,
.release = anon_pipe_buf_release,
- .steal = anon_pipe_buf_steal,
- .get = anon_pipe_buf_get,
+ .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;
+ int error, atomic;
if (chars > total_len)
chars = total_len;
- addr = ops->map(filp, pipe, buf);
- if (IS_ERR(addr)) {
+ error = ops->confirm(pipe, buf);
+ if (error) {
if (!ret)
- ret = PTR_ERR(addr);
+ error = ret;
break;
}
- error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars);
- ops->unmap(pipe, buf);
+
+ atomic = !iov_fault_in_pages_write(iov, chars);
+redo:
+ addr = ops->map(pipe, buf, atomic);
+ error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars, atomic);
+ ops->unmap(pipe, buf, addr);
if (unlikely(error)) {
+ /*
+ * Just retry with the slow path if we failed.
+ */
+ if (atomic) {
+ atomic = 0;
+ goto redo;
+ }
if (!ret)
- ret = -EFAULT;
+ ret = error;
break;
}
ret += chars;
if (!buf->len) {
buf->ops = NULL;
ops->release(pipe, buf);
- curbuf = (curbuf + 1) & (PIPE_BUFFERS-1);
+ curbuf = (curbuf + 1) & (pipe->buffers - 1);
pipe->curbuf = curbuf;
pipe->nrbufs = --bufs;
do_wakeup = 1;
/* 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)
-{
- 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)
+pipe_write(struct kiocb *iocb, 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;
chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */
if (pipe->nrbufs && chars != 0) {
int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) &
- (PIPE_BUFFERS-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;
- int error;
- addr = ops->map(filp, pipe, buf);
- if (IS_ERR(addr)) {
- error = PTR_ERR(addr);
+ error = ops->confirm(pipe, buf);
+ if (error)
goto out;
- }
+
+ iov_fault_in_pages_read(iov, chars);
+redo1:
+ addr = ops->map(pipe, buf, atomic);
error = pipe_iov_copy_from_user(offset + addr, iov,
- chars);
- ops->unmap(pipe, buf);
+ chars, atomic);
+ ops->unmap(pipe, buf, addr);
ret = error;
do_wakeup = 1;
- if (error)
+ if (error) {
+ if (atomic) {
+ atomic = 0;
+ goto redo1;
+ }
goto out;
+ }
buf->len += chars;
total_len -= chars;
ret = chars;
break;
}
bufs = pipe->nrbufs;
- if (bufs < PIPE_BUFFERS) {
- int newbuf = (pipe->curbuf + bufs) & (PIPE_BUFFERS-1);
+ if (bufs < pipe->buffers) {
+ int newbuf = (pipe->curbuf + bufs) & (pipe->buffers-1);
struct pipe_buffer *buf = pipe->bufs + newbuf;
struct page *page = pipe->tmp_page;
- int error;
+ char *src;
+ int error, atomic = 1;
if (!page) {
page = alloc_page(GFP_HIGHUSER);
if (chars > total_len)
chars = total_len;
- error = pipe_iov_copy_from_user(kmap(page), iov, chars);
- kunmap(page);
+ iov_fault_in_pages_read(iov, chars);
+redo2:
+ if (atomic)
+ src = kmap_atomic(page, KM_USER0);
+ else
+ src = kmap(page);
+
+ error = pipe_iov_copy_from_user(src, iov, chars,
+ atomic);
+ if (atomic)
+ kunmap_atomic(src, KM_USER0);
+ else
+ kunmap(page);
+
if (unlikely(error)) {
+ if (atomic) {
+ atomic = 0;
+ goto redo2;
+ }
if (!ret)
- ret = -EFAULT;
+ ret = error;
break;
}
ret += chars;
if (!total_len)
break;
}
- if (bufs < PIPE_BUFFERS)
+ if (bufs < pipe->buffers)
continue;
if (filp->f_flags & O_NONBLOCK) {
if (!ret)
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;
nrbufs = pipe->nrbufs;
while (--nrbufs >= 0) {
count += pipe->bufs[buf].len;
- buf = (buf+1) & (PIPE_BUFFERS-1);
+ buf = (buf+1) & (pipe->buffers - 1);
}
mutex_unlock(&inode->i_mutex);
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 (filp->f_mode & FMODE_WRITE) {
- mask |= (nrbufs < PIPE_BUFFERS) ? POLLOUT | POLLWRNORM : 0;
+ mask |= (nrbufs < pipe->buffers) ? POLLOUT | POLLWRNORM : 0;
/*
* Most Unices do not set POLLERR for FIFOs but on Linux they
* behave exactly like pipes for poll().
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);
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;
}
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);
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;
}
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;
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 = {
- .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 = {
- .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 = {
+const struct file_operations read_pipefifo_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,
pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL);
if (pipe) {
- init_waitqueue_head(&pipe->wait);
- pipe->r_counter = pipe->w_counter = 1;
- pipe->inode = inode;
+ pipe->bufs = kzalloc(sizeof(struct pipe_buffer) * PIPE_DEF_BUFFERS, GFP_KERNEL);
+ if (pipe->bufs) {
+ init_waitqueue_head(&pipe->wait);
+ pipe->r_counter = pipe->w_counter = 1;
+ pipe->inode = inode;
+ pipe->buffers = PIPE_DEF_BUFFERS;
+ return pipe;
+ }
+ kfree(pipe);
}
- return pipe;
+ return NULL;
}
void __free_pipe_info(struct pipe_inode_info *pipe)
{
int i;
- for (i = 0; i < PIPE_BUFFERS; i++) {
+ for (i = 0; i < pipe->buffers; i++) {
struct pipe_buffer *buf = pipe->bufs + i;
if (buf->ops)
buf->ops->release(pipe, buf);
}
if (pipe->tmp_page)
__free_page(pipe->tmp_page);
+ kfree(pipe->bufs);
kfree(pipe);
}
}
static struct vfsmount *pipe_mnt __read_mostly;
-static int pipefs_delete_dentry(struct dentry *dentry)
+
+/*
+ * pipefs_dname() is called from d_path().
+ */
+static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen)
{
- return 1;
+ 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,
+static const struct dentry_operations pipefs_dentry_operations = {
+ .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];
- 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;
+ int err;
+ struct inode *inode;
+ struct file *f;
+ struct path path;
+ struct qstr name = { .name = "" };
+ err = -ENFILE;
inode = get_pipe_inode();
if (!inode)
- goto close_f12;
+ goto err;
+
+ err = -ENOMEM;
+ path.dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &name);
+ if (!path.dentry)
+ goto err_inode;
+ path.mnt = mntget(pipe_mnt);
+
+ path.dentry->d_op = &pipefs_dentry_operations;
+ d_instantiate(path.dentry, inode);
+
+ err = -ENFILE;
+ f = alloc_file(&path, 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;
- error = get_unused_fd();
+ return f;
+
+ err_dentry:
+ free_pipe_info(inode);
+ path_put(&path);
+ return ERR_PTR(err);
+
+ err_inode:
+ free_pipe_info(inode);
+ iput(inode);
+ 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)
+{
+ /* Grab pipe from the writer */
+ struct file *f = alloc_file(&wrf->f_path, FMODE_READ,
+ &read_pipefifo_fops);
+ if (!f)
+ return ERR_PTR(-ENFILE);
+
+ path_get(&wrf->f_path);
+ f->f_flags = O_RDONLY | (flags & O_NONBLOCK);
+
+ 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 close_f12_inode;
- i = error;
+ goto err_read_pipe;
+ fdr = error;
- error = get_unused_fd();
+ error = get_unused_fd_flags(flags);
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);
- if (!dentry)
- goto close_f12_inode_i_j;
-
- 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;
+ 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;
-close_f12_inode_i_j:
- put_unused_fd(j);
-close_f12_inode_i:
- put_unused_fd(i);
-close_f12_inode:
- free_pipe_info(inode);
- iput(inode);
-close_f12:
- put_filp(f2);
-close_f1:
- put_filp(f1);
-no_files:
- return error;
+ 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;
+}
+
+/*
+ * 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);
+}
+
+/*
+ * Allocate a new array of pipe buffers and copy the info over. Returns the
+ * pipe size if successful, or return -ERROR on error.
+ */
+static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages)
+{
+ struct pipe_buffer *bufs;
+
+ /*
+ * We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't
+ * expect a lot of shrink+grow operations, just free and allocate
+ * again like we would do for growing. If the pipe currently
+ * contains more buffers than arg, then return busy.
+ */
+ if (nr_pages < pipe->nrbufs)
+ return -EBUSY;
+
+ bufs = kcalloc(nr_pages, sizeof(struct pipe_buffer), GFP_KERNEL);
+ if (unlikely(!bufs))
+ return -ENOMEM;
+
+ /*
+ * The pipe array wraps around, so just start the new one at zero
+ * and adjust the indexes.
+ */
+ if (pipe->nrbufs) {
+ unsigned int tail;
+ unsigned int head;
+
+ tail = pipe->curbuf + pipe->nrbufs;
+ if (tail < pipe->buffers)
+ tail = 0;
+ else
+ tail &= (pipe->buffers - 1);
+
+ head = pipe->nrbufs - tail;
+ if (head)
+ memcpy(bufs, pipe->bufs + pipe->curbuf, head * sizeof(struct pipe_buffer));
+ if (tail)
+ memcpy(bufs + head, pipe->bufs, tail * sizeof(struct pipe_buffer));
+ }
+
+ pipe->curbuf = 0;
+ kfree(pipe->bufs);
+ pipe->bufs = bufs;
+ pipe->buffers = nr_pages;
+ return nr_pages * PAGE_SIZE;
+}
+
+/*
+ * Currently we rely on the pipe array holding a power-of-2 number
+ * of pages.
+ */
+static inline unsigned int round_pipe_size(unsigned int size)
+{
+ unsigned long nr_pages;
+
+ nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ return roundup_pow_of_two(nr_pages) << PAGE_SHIFT;
+}
+
+/*
+ * This should work even if CONFIG_PROC_FS isn't set, as proc_dointvec_minmax
+ * will return an error.
+ */
+int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf,
+ size_t *lenp, loff_t *ppos)
+{
+ int ret;
+
+ ret = proc_dointvec_minmax(table, write, buf, lenp, ppos);
+ if (ret < 0 || !write)
+ return ret;
+
+ pipe_max_size = round_pipe_size(pipe_max_size);
+ return ret;
+}
+
+long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct pipe_inode_info *pipe;
+ long ret;
+
+ pipe = file->f_path.dentry->d_inode->i_pipe;
+ if (!pipe)
+ return -EBADF;
+
+ mutex_lock(&pipe->inode->i_mutex);
+
+ switch (cmd) {
+ case F_SETPIPE_SZ: {
+ unsigned int size, nr_pages;
+
+ size = round_pipe_size(arg);
+ nr_pages = size >> PAGE_SHIFT;
+
+ if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) {
+ ret = -EPERM;
+ goto out;
+ } else if (nr_pages < PAGE_SIZE) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = pipe_set_size(pipe, nr_pages);
+ break;
+ }
+ case F_GETPIPE_SZ:
+ ret = pipe->buffers * PAGE_SIZE;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+out:
+ mutex_unlock(&pipe->inode->i_mutex);
+ return ret;
}
/*
* any operations on the root directory. However, we need a non-trivial
* d_name - pipe: will go nicely and kill the special-casing in procfs.
*/
-
-static struct super_block *
-pipefs_get_sb(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data)
+static int pipefs_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data,
+ struct vfsmount *mnt)
{
- return get_sb_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC);
+ return get_sb_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC, mnt);
}
static struct file_system_type pipe_fs_type = {
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff