diff options
| -rw-r--r-- | fs/pipe.c | 76 |
1 files changed, 48 insertions, 28 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index b941e1951ea..e984beb93a0 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -44,7 +44,8 @@ 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); + prepare_to_wait(&pipe->wait, &wait, + TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE); if (pipe->inode) mutex_unlock(&pipe->inode->i_mutex); schedule(); @@ -93,7 +94,8 @@ 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 *pipe, struct pipe_buffer *buf) +static void anon_pipe_buf_release(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) { struct page *page = buf->page; @@ -102,25 +104,22 @@ static void anon_pipe_buf_release(struct pipe_inode_info *pipe, struct pipe_buff /* * 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; - } - - /* - * Otherwise just release our reference to it - */ - page_cache_release(page); + else + page_cache_release(page); } -static void *anon_pipe_buf_map(struct file *file, struct pipe_inode_info *pipe, struct pipe_buffer *buf) +static void * anon_pipe_buf_map(struct file *file, struct pipe_inode_info *pipe, + struct pipe_buffer *buf) { return kmap(buf->page); } -static void anon_pipe_buf_unmap(struct pipe_inode_info *pipe, struct pipe_buffer *buf) +static void anon_pipe_buf_unmap(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) { kunmap(buf->page); } @@ -182,7 +181,8 @@ pipe_readv(struct file *filp, const struct iovec *_iov, error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars); ops->unmap(pipe, buf); if (unlikely(error)) { - if (!ret) ret = -EFAULT; + if (!ret) + ret = -EFAULT; break; } ret += chars; @@ -218,7 +218,8 @@ 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) { @@ -228,7 +229,8 @@ pipe_readv(struct file *filp, const struct iovec *_iov, 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); @@ -242,6 +244,7 @@ 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); } @@ -276,10 +279,12 @@ 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 (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) { void *addr; int error; @@ -306,9 +311,11 @@ pipe_writev(struct file *filp, const struct iovec *_iov, for (;;) { int bufs; + if (!pipe->readers) { send_sig(SIGPIPE, current, 0); - if (!ret) ret = -EPIPE; + if (!ret) + ret = -EPIPE; break; } bufs = pipe->nrbufs; @@ -326,7 +333,7 @@ pipe_writev(struct file *filp, const struct iovec *_iov, } 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? @@ -339,7 +346,8 @@ pipe_writev(struct file *filp, const struct iovec *_iov, error = pipe_iov_copy_from_user(kmap(page), iov, chars); kunmap(page); if (unlikely(error)) { - if (!ret) ret = -EFAULT; + if (!ret) + ret = -EFAULT; break; } ret += chars; @@ -359,11 +367,13 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 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) { @@ -391,6 +401,7 @@ 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); } @@ -401,7 +412,8 @@ bad_pipe_r(struct file *filp, char __user *buf, size_t count, loff_t *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; } @@ -475,6 +487,7 @@ pipe_release(struct inode *inode, int decr, int decw) pipe = inode->i_pipe; pipe->readers -= decr; pipe->writers -= decw; + if (!pipe->readers && !pipe->writers) { free_pipe_info(inode); } else { @@ -525,14 +538,15 @@ static int 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); @@ -720,6 +734,7 @@ static int pipefs_delete_dentry(struct dentry *dentry) { return 1; } + static struct dentry_operations pipefs_dentry_operations = { .d_delete = pipefs_delete_dentry, }; @@ -757,6 +772,7 @@ static struct inode * get_pipe_inode(void) fail_iput: iput(inode); + fail_inode: return NULL; } @@ -769,7 +785,7 @@ int do_pipe(int *fd) struct inode * inode; struct file *f1, *f2; int error; - int i,j; + int i, j; error = -ENFILE; f1 = get_empty_filp(); @@ -802,6 +818,7 @@ int do_pipe(int *fd) 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)); @@ -825,6 +842,7 @@ int do_pipe(int *fd) fd_install(j, f2); fd[0] = i; fd[1] = j; + return 0; close_f12_inode_i_j: @@ -849,8 +867,9 @@ no_files: * 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 struct super_block * +pipefs_get_sb(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data) { return get_sb_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC); } @@ -864,6 +883,7 @@ 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)) { |