X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=fs%2Fpipe.c;h=f31e2d472984182d8d06ebadc4e66c8dd423b735;hp=4384c929094354d84f27936b1b15c6001b9d9dd5;hb=1d862f41222b7f385bada9f85a67ca5592ffd33e;hpb=fa3536cc144c1298f2ed9416c33f3b77fa2cd37a diff --git a/fs/pipe.c b/fs/pipe.c index 4384c92..f31e2d4 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -11,15 +11,31 @@ #include #include #include +#include #include #include #include #include +#include +#include +#include +#include #include #include /* + * 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) @@ -34,8 +50,44 @@ * -- Manfred Spraul 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 inode * inode) +void pipe_wait(struct pipe_inode_info *pipe) { DEFINE_WAIT(wait); @@ -43,15 +95,16 @@ void pipe_wait(struct inode * inode) * Pipes are system-local resources, so sleeping on them * is considered a noninteractive wait: */ - prepare_to_wait(PIPE_WAIT(*inode), &wait, TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE); - mutex_unlock(PIPE_MUTEX(*inode)); + prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE); + pipe_unlock(pipe); schedule(); - finish_wait(PIPE_WAIT(*inode), &wait); - mutex_lock(PIPE_MUTEX(*inode)); + finish_wait(&pipe->wait, &wait); + 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; @@ -60,8 +113,13 @@ pipe_iov_copy_from_user(void *to, struct iovec *iov, unsigned long len) 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; @@ -71,7 +129,8 @@ pipe_iov_copy_from_user(void *to, struct iovec *iov, unsigned long len) } 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; @@ -80,8 +139,13 @@ pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len) 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; @@ -90,40 +154,204 @@ pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len) return 0; } -static void anon_pipe_buf_release(struct pipe_inode_info *info, 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; - if (info->tmp_page) { - __free_page(page); - return; + len -= this_len; + iov++; } - info->tmp_page = page; + + return len; } -static void *anon_pipe_buf_map(struct file *file, struct pipe_inode_info *info, struct pipe_buffer *buf) +/* + * 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; + + /* + * 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. (Otherwise just release our reference to it) + */ + if (page_count(page) == 1 && !pipe->tmp_page) + pipe->tmp_page = page; + else + 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) +{ + 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); + +/** + * 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); +} +EXPORT_SYMBOL(generic_pipe_buf_get); + +/** + * 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; +} +EXPORT_SYMBOL(generic_pipe_buf_confirm); -static void anon_pipe_buf_unmap(struct pipe_inode_info *info, struct pipe_buffer *buf) +/** + * 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) { - kunmap(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 = 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 pipe_inode_info *info; + 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; struct iovec *iov = (struct iovec *)_iov; @@ -136,26 +364,43 @@ pipe_readv(struct file *filp, const struct iovec *_iov, do_wakeup = 0; ret = 0; - mutex_lock(PIPE_MUTEX(*inode)); - info = inode->i_pipe; + mutex_lock(&inode->i_mutex); + pipe = inode->i_pipe; for (;;) { - int bufs = info->nrbufs; + int bufs = pipe->nrbufs; if (bufs) { - int curbuf = info->curbuf; - struct pipe_buffer *buf = info->bufs + curbuf; - struct pipe_buf_operations *ops = buf->ops; + int curbuf = pipe->curbuf; + struct pipe_buffer *buf = pipe->bufs + curbuf; + 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, info, buf); - error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars); - ops->unmap(info, buf); + error = ops->confirm(pipe, buf); + if (error) { + if (!ret) + error = ret; + break; + } + + 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; @@ -163,10 +408,10 @@ pipe_readv(struct file *filp, const struct iovec *_iov, buf->len -= chars; if (!buf->len) { buf->ops = NULL; - ops->release(info, buf); - curbuf = (curbuf + 1) & (PIPE_BUFFERS-1); - info->curbuf = curbuf; - info->nrbufs = --bufs; + ops->release(pipe, buf); + curbuf = (curbuf + 1) & (pipe->buffers - 1); + pipe->curbuf = curbuf; + pipe->nrbufs = --bufs; do_wakeup = 1; } total_len -= chars; @@ -175,9 +420,9 @@ pipe_readv(struct file *filp, const struct iovec *_iov, } if (bufs) /* More to do? */ continue; - if (!PIPE_WRITERS(*inode)) + if (!pipe->writers) break; - if (!PIPE_WAITING_WRITERS(*inode)) { + if (!pipe->waiting_writers) { /* syscall merging: Usually we must not sleep * if O_NONBLOCK is set, or if we got some data. * But if a writer sleeps in kernel space, then @@ -191,20 +436,22 @@ pipe_readv(struct file *filp, const struct iovec *_iov, } } if (signal_pending(current)) { - if (!ret) ret = -ERESTARTSYS; + if (!ret) + ret = -ERESTARTSYS; break; } if (do_wakeup) { - wake_up_interruptible_sync(PIPE_WAIT(*inode)); - kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT); + wake_up_interruptible_sync(&pipe->wait); + kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } - pipe_wait(inode); + pipe_wait(pipe); } - mutex_unlock(PIPE_MUTEX(*inode)); - /* Signal writers asynchronously that there is more room. */ + mutex_unlock(&inode->i_mutex); + + /* Signal writers asynchronously that there is more room. */ if (do_wakeup) { - wake_up_interruptible(PIPE_WAIT(*inode)); - kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT); + wake_up_interruptible_sync(&pipe->wait); + kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } if (ret > 0) file_accessed(filp); @@ -212,18 +459,12 @@ pipe_readv(struct file *filp, const struct iovec *_iov, } 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 pipe_inode_info *info; + 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; struct iovec *iov = (struct iovec *)_iov; @@ -237,10 +478,10 @@ pipe_writev(struct file *filp, const struct iovec *_iov, do_wakeup = 0; ret = 0; - mutex_lock(PIPE_MUTEX(*inode)); - info = inode->i_pipe; + mutex_lock(&inode->i_mutex); + pipe = inode->i_pipe; - if (!PIPE_READERS(*inode)) { + if (!pipe->readers) { send_sig(SIGPIPE, current, 0); ret = -EPIPE; goto out; @@ -248,19 +489,36 @@ pipe_writev(struct file *filp, const struct iovec *_iov, /* We try to merge small writes */ chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */ - if (info->nrbufs && chars != 0) { - int lastbuf = (info->curbuf + info->nrbufs - 1) & (PIPE_BUFFERS-1); - struct pipe_buffer *buf = info->bufs + lastbuf; - struct pipe_buf_operations *ops = buf->ops; + if (pipe->nrbufs && chars != 0) { + int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) & + (pipe->buffers - 1); + struct pipe_buffer *buf = pipe->bufs + lastbuf; + const struct pipe_buf_operations *ops = buf->ops; int offset = buf->offset + buf->len; + if (ops->can_merge && offset + chars <= PAGE_SIZE) { - void *addr = ops->map(filp, info, buf); - int error = pipe_iov_copy_from_user(offset + addr, iov, chars); - ops->unmap(info, buf); + int error, atomic = 1; + void *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, 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; @@ -271,17 +529,20 @@ pipe_writev(struct file *filp, const struct iovec *_iov, for (;;) { int bufs; - if (!PIPE_READERS(*inode)) { + + if (!pipe->readers) { send_sig(SIGPIPE, current, 0); - if (!ret) ret = -EPIPE; + if (!ret) + ret = -EPIPE; break; } - bufs = info->nrbufs; - if (bufs < PIPE_BUFFERS) { - int newbuf = (info->curbuf + bufs) & (PIPE_BUFFERS-1); - struct pipe_buffer *buf = info->bufs + newbuf; - struct page *page = info->tmp_page; - int error; + bufs = pipe->nrbufs; + 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; + char *src; + int error, atomic = 1; if (!page) { page = alloc_page(GFP_HIGHUSER); @@ -289,9 +550,9 @@ pipe_writev(struct file *filp, const struct iovec *_iov, ret = ret ? : -ENOMEM; break; } - info->tmp_page = page; + 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? @@ -301,10 +562,27 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 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; @@ -314,37 +592,39 @@ pipe_writev(struct file *filp, const struct iovec *_iov, buf->ops = &anon_pipe_buf_ops; buf->offset = 0; buf->len = chars; - info->nrbufs = ++bufs; - info->tmp_page = NULL; + pipe->nrbufs = ++bufs; + pipe->tmp_page = NULL; total_len -= chars; if (!total_len) break; } - if (bufs < PIPE_BUFFERS) + 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) { - wake_up_interruptible_sync(PIPE_WAIT(*inode)); - kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN); + wake_up_interruptible_sync(&pipe->wait); + kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); do_wakeup = 0; } - PIPE_WAITING_WRITERS(*inode)++; - pipe_wait(inode); - PIPE_WAITING_WRITERS(*inode)--; + pipe->waiting_writers++; + pipe_wait(pipe); + pipe->waiting_writers--; } out: - mutex_unlock(PIPE_MUTEX(*inode)); + mutex_unlock(&inode->i_mutex); if (do_wakeup) { - wake_up_interruptible(PIPE_WAIT(*inode)); - kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN); + wake_up_interruptible_sync(&pipe->wait); + kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); } if (ret > 0) file_update_time(filp); @@ -352,45 +632,37 @@ out: } 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; } 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; } -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 pipe_inode_info *info; + struct inode *inode = filp->f_path.dentry->d_inode; + struct pipe_inode_info *pipe; int count, buf, nrbufs; switch (cmd) { case FIONREAD: - mutex_lock(PIPE_MUTEX(*inode)); - info = inode->i_pipe; + mutex_lock(&inode->i_mutex); + pipe = inode->i_pipe; count = 0; - buf = info->curbuf; - nrbufs = info->nrbufs; + buf = pipe->curbuf; + nrbufs = pipe->nrbufs; while (--nrbufs >= 0) { - count += info->bufs[buf].len; - buf = (buf+1) & (PIPE_BUFFERS-1); + count += pipe->bufs[buf].len; + buf = (buf+1) & (pipe->buffers - 1); } - mutex_unlock(PIPE_MUTEX(*inode)); + mutex_unlock(&inode->i_mutex); + return put_user(count, (int __user *)arg); default: return -EINVAL; @@ -402,28 +674,28 @@ static unsigned int pipe_poll(struct file *filp, poll_table *wait) { unsigned int mask; - struct inode *inode = filp->f_dentry->d_inode; - struct pipe_inode_info *info = inode->i_pipe; + struct inode *inode = filp->f_path.dentry->d_inode; + struct pipe_inode_info *pipe = inode->i_pipe; int nrbufs; - poll_wait(filp, PIPE_WAIT(*inode), wait); + poll_wait(filp, &pipe->wait, wait); /* Reading only -- no need for acquiring the semaphore. */ - nrbufs = info->nrbufs; + nrbufs = pipe->nrbufs; mask = 0; if (filp->f_mode & FMODE_READ) { mask = (nrbufs > 0) ? POLLIN | POLLRDNORM : 0; - if (!PIPE_WRITERS(*inode) && filp->f_version != PIPE_WCOUNTER(*inode)) + if (!pipe->writers && filp->f_version != pipe->w_counter) mask |= POLLHUP; } 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(*inode)) + if (!pipe->readers) mask |= POLLERR; } @@ -433,17 +705,21 @@ pipe_poll(struct file *filp, poll_table *wait) static int pipe_release(struct inode *inode, int decr, int decw) { - mutex_lock(PIPE_MUTEX(*inode)); - PIPE_READERS(*inode) -= decr; - PIPE_WRITERS(*inode) -= decw; - if (!PIPE_READERS(*inode) && !PIPE_WRITERS(*inode)) { + struct pipe_inode_info *pipe; + + mutex_lock(&inode->i_mutex); + pipe = inode->i_pipe; + pipe->readers -= decr; + pipe->writers -= decw; + + if (!pipe->readers && !pipe->writers) { free_pipe_info(inode); } else { - wake_up_interruptible(PIPE_WAIT(*inode)); - kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN); - kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT); + wake_up_interruptible_sync(&pipe->wait); + kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); + kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } - mutex_unlock(PIPE_MUTEX(*inode)); + mutex_unlock(&inode->i_mutex); return 0; } @@ -451,70 +727,59 @@ pipe_release(struct inode *inode, int decr, int decw) 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(PIPE_MUTEX(*inode)); - retval = fasync_helper(fd, filp, on, PIPE_FASYNC_READERS(*inode)); - mutex_unlock(PIPE_MUTEX(*inode)); - - if (retval < 0) - return retval; + mutex_lock(&inode->i_mutex); + retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers); + mutex_unlock(&inode->i_mutex); - 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(PIPE_MUTEX(*inode)); - retval = fasync_helper(fd, filp, on, PIPE_FASYNC_WRITERS(*inode)); - mutex_unlock(PIPE_MUTEX(*inode)); - - if (retval < 0) - return retval; + mutex_lock(&inode->i_mutex); + retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers); + mutex_unlock(&inode->i_mutex); - 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(PIPE_MUTEX(*inode)); - - retval = fasync_helper(fd, filp, on, PIPE_FASYNC_READERS(*inode)); - - if (retval >= 0) - retval = fasync_helper(fd, filp, on, PIPE_FASYNC_WRITERS(*inode)); - - mutex_unlock(PIPE_MUTEX(*inode)); - - if (retval < 0) - return retval; - - return 0; + mutex_lock(&inode->i_mutex); + retval = fasync_helper(fd, filp, on, &pipe->fasync_readers); + 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); + 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); } @@ -523,7 +788,6 @@ pipe_rdwr_release(struct inode *inode, struct file *filp) { 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); @@ -532,169 +796,171 @@ pipe_rdwr_release(struct inode *inode, struct file *filp) 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. */ - mutex_lock(PIPE_MUTEX(*inode)); - PIPE_READERS(*inode)++; - mutex_unlock(PIPE_MUTEX(*inode)); + int ret = -ENOENT; - return 0; + mutex_lock(&inode->i_mutex); + + if (inode->i_pipe) { + ret = 0; + inode->i_pipe->readers++; + } + + mutex_unlock(&inode->i_mutex); + + return ret; } static int pipe_write_open(struct inode *inode, struct file *filp) { - mutex_lock(PIPE_MUTEX(*inode)); - PIPE_WRITERS(*inode)++; - mutex_unlock(PIPE_MUTEX(*inode)); + int ret = -ENOENT; - return 0; + mutex_lock(&inode->i_mutex); + + if (inode->i_pipe) { + ret = 0; + inode->i_pipe->writers++; + } + + mutex_unlock(&inode->i_mutex); + + return ret; } static int pipe_rdwr_open(struct inode *inode, struct file *filp) { - mutex_lock(PIPE_MUTEX(*inode)); - if (filp->f_mode & FMODE_READ) - PIPE_READERS(*inode)++; - if (filp->f_mode & FMODE_WRITE) - PIPE_WRITERS(*inode)++; - mutex_unlock(PIPE_MUTEX(*inode)); + int ret = -ENOENT; - return 0; + mutex_lock(&inode->i_mutex); + + 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 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. */ -struct file_operations read_fifo_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, }; -struct file_operations write_fifo_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, }; -struct file_operations rdwr_fifo_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 file_operations read_pipe_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, -}; - -static struct file_operations write_pipe_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, -}; +struct pipe_inode_info * alloc_pipe_info(struct inode *inode) +{ + struct pipe_inode_info *pipe; + + pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL); + if (pipe) { + 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); + } -static struct file_operations rdwr_pipe_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, -}; + return NULL; +} -void free_pipe_info(struct inode *inode) +void __free_pipe_info(struct pipe_inode_info *pipe) { int i; - struct pipe_inode_info *info = inode->i_pipe; - inode->i_pipe = NULL; - for (i = 0; i < PIPE_BUFFERS; i++) { - struct pipe_buffer *buf = info->bufs + i; + for (i = 0; i < pipe->buffers; i++) { + struct pipe_buffer *buf = pipe->bufs + i; if (buf->ops) - buf->ops->release(info, buf); + buf->ops->release(pipe, buf); } - if (info->tmp_page) - __free_page(info->tmp_page); - kfree(info); + if (pipe->tmp_page) + __free_page(pipe->tmp_page); + kfree(pipe->bufs); + kfree(pipe); } -struct inode* pipe_new(struct inode* inode) +void free_pipe_info(struct inode *inode) { - struct pipe_inode_info *info; - - info = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL); - if (!info) - goto fail_page; - inode->i_pipe = info; - - init_waitqueue_head(PIPE_WAIT(*inode)); - PIPE_RCOUNTER(*inode) = PIPE_WCOUNTER(*inode) = 1; - - return inode; -fail_page: - return NULL; + __free_pipe_info(inode->i_pipe); + inode->i_pipe = NULL; } 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) { struct inode *inode = new_inode(pipe_mnt->mnt_sb); + struct pipe_inode_info *pipe; if (!inode) goto fail_inode; - if(!pipe_new(inode)) + pipe = alloc_pipe_info(inode); + if (!pipe) goto fail_iput; - PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 1; - inode->i_fop = &rdwr_pipe_fops; + inode->i_pipe = pipe; + + pipe->readers = pipe->writers = 1; + inode->i_fop = &rdwr_pipefifo_fops; /* * Mark the inode dirty from the very beginning, @@ -704,97 +970,272 @@ static struct inode * get_pipe_inode(void) */ 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; fail_iput: iput(inode); + fail_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; + + return f; + + err_dentry: + free_pipe_info(inode); + path_put(&path); + return ERR_PTR(err); - error = get_unused_fd(); + 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; } /* @@ -803,11 +1244,11 @@ no_files: * 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 = { @@ -819,6 +1260,7 @@ 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)) {