* 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 | TASK_NONINTERACTIVE);
if (pipe->inode)
mutex_unlock(&pipe->inode->i_mutex);
schedule();
}
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;
}
-static void anon_pipe_buf_release(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
+/*
+ * 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)
{
- struct page *page = buf->page;
+ 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++;
- buf->flags &= ~PIPE_BUF_FLAG_STOLEN;
+ 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;
/*
* 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
- * allocation cache
+ * allocation cache. (Otherwise just release our reference to it)
*/
- if (page_count(page) == 1 && !pipe->tmp_page) {
+ if (page_count(page) == 1 && !pipe->tmp_page)
pipe->tmp_page = page;
- return;
+ else
+ page_cache_release(page);
+}
+
+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);
}
- /*
- * Otherwise just release our reference to it
- */
- page_cache_release(page);
+ return kmap(buf->page);
}
-static void *anon_pipe_buf_map(struct file *file, struct pipe_inode_info *pipe, struct pipe_buffer *buf)
+void generic_pipe_buf_unmap(struct pipe_inode_info *pipe,
+ struct pipe_buffer *buf, void *map_data)
{
- return kmap(buf->page);
+ if (buf->flags & PIPE_BUF_FLAG_ATOMIC) {
+ buf->flags &= ~PIPE_BUF_FLAG_ATOMIC;
+ kunmap_atomic(map_data, KM_USER0);
+ } else
+ kunmap(buf->page);
+}
+
+int generic_pipe_buf_steal(struct pipe_inode_info *pipe,
+ struct pipe_buffer *buf)
+{
+ struct page *page = buf->page;
+
+ if (page_count(page) == 1) {
+ lock_page(page);
+ return 0;
+ }
+
+ return 1;
}
-static void anon_pipe_buf_unmap(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
+void generic_pipe_buf_get(struct pipe_inode_info *info, struct pipe_buffer *buf)
{
- kunmap(buf->page);
+ page_cache_get(buf->page);
}
-static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,
- struct pipe_buffer *buf)
+int generic_pipe_buf_pin(struct pipe_inode_info *info, struct pipe_buffer *buf)
{
- buf->flags |= PIPE_BUF_FLAG_STOLEN;
return 0;
}
static 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,
+ .pin = generic_pipe_buf_pin,
.release = anon_pipe_buf_release,
- .steal = anon_pipe_buf_steal,
+ .steal = generic_pipe_buf_steal,
+ .get = generic_pipe_buf_get,
};
static ssize_t
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->pin(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)) {
- if (!ret) ret = -EFAULT;
+ /*
+ * Just retry with the slow path if we failed.
+ */
+ if (atomic) {
+ atomic = 0;
+ goto redo;
+ }
+ if (!ret)
+ ret = error;
break;
}
ret += chars;
}
}
if (signal_pending(current)) {
- if (!ret) ret = -ERESTARTSYS;
+ if (!ret)
+ ret = -ERESTARTSYS;
break;
}
if (do_wakeup) {
pipe_wait(pipe);
}
mutex_unlock(&inode->i_mutex);
- /* Signal writers asynchronously that there is more room. */
+
+ /* Signal writers asynchronously that there is more room. */
if (do_wakeup) {
wake_up_interruptible(&pipe->wait);
kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
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);
}
/* We try to merge small writes */
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);
+ int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) &
+ (PIPE_BUFFERS-1);
struct pipe_buffer *buf = pipe->bufs + lastbuf;
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->pin(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;
for (;;) {
int bufs;
+
if (!pipe->readers) {
send_sig(SIGPIPE, current, 0);
- if (!ret) ret = -EPIPE;
+ if (!ret)
+ ret = -EPIPE;
break;
}
bufs = pipe->nrbufs;
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);
}
pipe->tmp_page = page;
}
- /* Always wakeup, even if the copy fails. Otherwise
+ /* Always wake up, even if the copy fails. Otherwise
* we lock up (O_NONBLOCK-)readers that sleep due to
* syscall merging.
* FIXME! Is this really true?
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 (!ret) ret = -EFAULT;
+ if (atomic) {
+ atomic = 0;
+ goto redo2;
+ }
+ if (!ret)
+ ret = error;
break;
}
ret += chars;
if (bufs < PIPE_BUFFERS)
continue;
if (filp->f_flags & O_NONBLOCK) {
- if (!ret) ret = -EAGAIN;
+ if (!ret)
+ ret = -EAGAIN;
break;
}
if (signal_pending(current)) {
- if (!ret) ret = -ERESTARTSYS;
+ if (!ret)
+ ret = -ERESTARTSYS;
break;
}
if (do_wakeup) {
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_w(struct file *filp, const char __user *buf, size_t count, loff_t *ppos)
+bad_pipe_w(struct file *filp, const char __user *buf, size_t count,
+ loff_t *ppos)
{
return -EBADF;
}
pipe = inode->i_pipe;
pipe->readers -= decr;
pipe->writers -= decw;
+
if (!pipe->readers && !pipe->writers) {
free_pipe_info(inode);
} else {
pipe_rdwr_fasync(int fd, struct file *filp, int on)
{
struct inode *inode = filp->f_dentry->d_inode;
+ struct pipe_inode_info *pipe = inode->i_pipe;
int retval;
mutex_lock(&inode->i_mutex);
- retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers);
+ retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);
if (retval >= 0)
- retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers);
+ retval = fasync_helper(fd, filp, on, &pipe->fasync_writers);
mutex_unlock(&inode->i_mutex);
{
return 1;
}
+
static struct dentry_operations pipefs_dentry_operations = {
.d_delete = pipefs_delete_dentry,
};
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;
fail_iput:
iput(inode);
+
fail_inode:
return NULL;
}
struct inode * inode;
struct file *f1, *f2;
int error;
- int i,j;
+ int i, j;
error = -ENFILE;
f1 = get_empty_filp();
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));
fd_install(j, f2);
fd[0] = i;
fd[1] = j;
+
return 0;
close_f12_inode_i_j:
* 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 = {
static int __init init_pipe_fs(void)
{
int err = register_filesystem(&pipe_fs_type);
+
if (!err) {
pipe_mnt = kern_mount(&pipe_fs_type);
if (IS_ERR(pipe_mnt)) {
git.openpandora.org / pandora-kernel.git / blobdiff