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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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pipe: add support for shrinking and growing pipes
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for growing and shrinking the size of a pipe and adjusts pipe.c and splice.c (and relay and network splice) usage to work with these larger (or smaller) pipes. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe
parent
3d42b36128
commit
35f3d14dbb
@ -14,6 +14,7 @@
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#include <linux/dnotify.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/pipe_fs_i.h>
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#include <linux/security.h>
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#include <linux/ptrace.h>
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#include <linux/signal.h>
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@ -412,6 +413,10 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
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case F_NOTIFY:
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err = fcntl_dirnotify(fd, filp, arg);
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break;
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case F_SETPIPE_SZ:
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case F_GETPIPE_SZ:
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err = pipe_fcntl(filp, cmd, arg);
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break;
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default:
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break;
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}
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107
fs/pipe.c
107
fs/pipe.c
@ -11,6 +11,7 @@
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/log2.h>
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#include <linux/mount.h>
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#include <linux/pipe_fs_i.h>
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#include <linux/uio.h>
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@ -390,7 +391,7 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov,
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if (!buf->len) {
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buf->ops = NULL;
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ops->release(pipe, buf);
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curbuf = (curbuf + 1) & (PIPE_BUFFERS-1);
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curbuf = (curbuf + 1) & (pipe->buffers - 1);
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pipe->curbuf = curbuf;
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pipe->nrbufs = --bufs;
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do_wakeup = 1;
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@ -472,7 +473,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov,
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chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */
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if (pipe->nrbufs && chars != 0) {
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int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) &
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(PIPE_BUFFERS-1);
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(pipe->buffers - 1);
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struct pipe_buffer *buf = pipe->bufs + lastbuf;
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const struct pipe_buf_operations *ops = buf->ops;
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int offset = buf->offset + buf->len;
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@ -518,8 +519,8 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov,
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break;
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}
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bufs = pipe->nrbufs;
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if (bufs < PIPE_BUFFERS) {
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int newbuf = (pipe->curbuf + bufs) & (PIPE_BUFFERS-1);
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if (bufs < pipe->buffers) {
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int newbuf = (pipe->curbuf + bufs) & (pipe->buffers-1);
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struct pipe_buffer *buf = pipe->bufs + newbuf;
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struct page *page = pipe->tmp_page;
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char *src;
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@ -580,7 +581,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov,
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if (!total_len)
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break;
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}
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if (bufs < PIPE_BUFFERS)
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if (bufs < pipe->buffers)
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continue;
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if (filp->f_flags & O_NONBLOCK) {
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if (!ret)
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@ -640,7 +641,7 @@ static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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nrbufs = pipe->nrbufs;
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while (--nrbufs >= 0) {
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count += pipe->bufs[buf].len;
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buf = (buf+1) & (PIPE_BUFFERS-1);
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buf = (buf+1) & (pipe->buffers - 1);
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}
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mutex_unlock(&inode->i_mutex);
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@ -671,7 +672,7 @@ pipe_poll(struct file *filp, poll_table *wait)
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}
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if (filp->f_mode & FMODE_WRITE) {
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mask |= (nrbufs < PIPE_BUFFERS) ? POLLOUT | POLLWRNORM : 0;
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mask |= (nrbufs < pipe->buffers) ? POLLOUT | POLLWRNORM : 0;
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/*
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* Most Unices do not set POLLERR for FIFOs but on Linux they
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* behave exactly like pipes for poll().
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@ -877,25 +878,32 @@ struct pipe_inode_info * alloc_pipe_info(struct inode *inode)
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pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL);
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if (pipe) {
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init_waitqueue_head(&pipe->wait);
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pipe->r_counter = pipe->w_counter = 1;
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pipe->inode = inode;
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pipe->bufs = kzalloc(sizeof(struct pipe_buffer) * PIPE_DEF_BUFFERS, GFP_KERNEL);
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if (pipe->bufs) {
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init_waitqueue_head(&pipe->wait);
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pipe->r_counter = pipe->w_counter = 1;
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pipe->inode = inode;
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pipe->buffers = PIPE_DEF_BUFFERS;
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return pipe;
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}
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kfree(pipe);
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}
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return pipe;
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return NULL;
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}
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void __free_pipe_info(struct pipe_inode_info *pipe)
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{
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int i;
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for (i = 0; i < PIPE_BUFFERS; i++) {
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for (i = 0; i < pipe->buffers; i++) {
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struct pipe_buffer *buf = pipe->bufs + i;
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if (buf->ops)
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buf->ops->release(pipe, buf);
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}
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if (pipe->tmp_page)
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__free_page(pipe->tmp_page);
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kfree(pipe->bufs);
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kfree(pipe);
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}
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@ -1093,6 +1101,81 @@ SYSCALL_DEFINE1(pipe, int __user *, fildes)
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return sys_pipe2(fildes, 0);
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}
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/*
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* Allocate a new array of pipe buffers and copy the info over. Returns the
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* pipe size if successful, or return -ERROR on error.
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*/
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static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
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{
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struct pipe_buffer *bufs;
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/*
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* Must be a power-of-2 currently
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*/
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if (!is_power_of_2(arg))
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return -EINVAL;
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/*
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* We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't
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* expect a lot of shrink+grow operations, just free and allocate
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* again like we would do for growing. If the pipe currently
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* contains more buffers than arg, then return busy.
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*/
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if (arg < pipe->nrbufs)
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return -EBUSY;
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bufs = kcalloc(arg, sizeof(struct pipe_buffer), GFP_KERNEL);
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if (unlikely(!bufs))
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return -ENOMEM;
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/*
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* The pipe array wraps around, so just start the new one at zero
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* and adjust the indexes.
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*/
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if (pipe->nrbufs) {
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const unsigned int tail = pipe->nrbufs & (pipe->buffers - 1);
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const unsigned int head = pipe->nrbufs - tail;
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if (head)
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memcpy(bufs, pipe->bufs + pipe->curbuf, head * sizeof(struct pipe_buffer));
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if (tail)
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memcpy(bufs + head, pipe->bufs + pipe->curbuf, tail * sizeof(struct pipe_buffer));
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}
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pipe->curbuf = 0;
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kfree(pipe->bufs);
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pipe->bufs = bufs;
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pipe->buffers = arg;
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return arg;
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}
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long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
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{
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struct pipe_inode_info *pipe;
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long ret;
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pipe = file->f_path.dentry->d_inode->i_pipe;
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if (!pipe)
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return -EBADF;
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mutex_lock(&pipe->inode->i_mutex);
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switch (cmd) {
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case F_SETPIPE_SZ:
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ret = pipe_set_size(pipe, arg);
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break;
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case F_GETPIPE_SZ:
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ret = pipe->buffers;
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break;
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default:
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ret = -EINVAL;
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break;
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}
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mutex_unlock(&pipe->inode->i_mutex);
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return ret;
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}
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/*
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* pipefs should _never_ be mounted by userland - too much of security hassle,
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* no real gain from having the whole whorehouse mounted. So we don't need
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153
fs/splice.c
153
fs/splice.c
@ -193,8 +193,8 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
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break;
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}
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if (pipe->nrbufs < PIPE_BUFFERS) {
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int newbuf = (pipe->curbuf + pipe->nrbufs) & (PIPE_BUFFERS - 1);
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if (pipe->nrbufs < pipe->buffers) {
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int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
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struct pipe_buffer *buf = pipe->bufs + newbuf;
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buf->page = spd->pages[page_nr];
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@ -214,7 +214,7 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
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if (!--spd->nr_pages)
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break;
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if (pipe->nrbufs < PIPE_BUFFERS)
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if (pipe->nrbufs < pipe->buffers)
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continue;
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break;
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@ -265,6 +265,36 @@ static void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
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page_cache_release(spd->pages[i]);
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}
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/*
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* Check if we need to grow the arrays holding pages and partial page
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* descriptions.
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*/
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int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
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{
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if (pipe->buffers <= PIPE_DEF_BUFFERS)
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return 0;
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spd->pages = kmalloc(pipe->buffers * sizeof(struct page *), GFP_KERNEL);
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spd->partial = kmalloc(pipe->buffers * sizeof(struct partial_page), GFP_KERNEL);
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if (spd->pages && spd->partial)
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return 0;
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kfree(spd->pages);
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kfree(spd->partial);
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return -ENOMEM;
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}
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void splice_shrink_spd(struct pipe_inode_info *pipe,
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struct splice_pipe_desc *spd)
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{
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if (pipe->buffers <= PIPE_DEF_BUFFERS)
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return;
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kfree(spd->pages);
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kfree(spd->partial);
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}
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static int
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__generic_file_splice_read(struct file *in, loff_t *ppos,
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struct pipe_inode_info *pipe, size_t len,
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@ -272,8 +302,8 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
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{
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struct address_space *mapping = in->f_mapping;
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unsigned int loff, nr_pages, req_pages;
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struct page *pages[PIPE_BUFFERS];
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struct partial_page partial[PIPE_BUFFERS];
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struct page *pages[PIPE_DEF_BUFFERS];
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struct partial_page partial[PIPE_DEF_BUFFERS];
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struct page *page;
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pgoff_t index, end_index;
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loff_t isize;
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@ -286,15 +316,18 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
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.spd_release = spd_release_page,
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};
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if (splice_grow_spd(pipe, &spd))
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return -ENOMEM;
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index = *ppos >> PAGE_CACHE_SHIFT;
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loff = *ppos & ~PAGE_CACHE_MASK;
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req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
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nr_pages = min(req_pages, (unsigned)PIPE_BUFFERS);
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nr_pages = min(req_pages, pipe->buffers);
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/*
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* Lookup the (hopefully) full range of pages we need.
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*/
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spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, pages);
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spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, spd.pages);
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index += spd.nr_pages;
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/*
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@ -335,7 +368,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
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unlock_page(page);
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}
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pages[spd.nr_pages++] = page;
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spd.pages[spd.nr_pages++] = page;
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index++;
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}
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@ -356,7 +389,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
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* this_len is the max we'll use from this page
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*/
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this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
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page = pages[page_nr];
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page = spd.pages[page_nr];
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if (PageReadahead(page))
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page_cache_async_readahead(mapping, &in->f_ra, in,
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@ -393,8 +426,8 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
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error = -ENOMEM;
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break;
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}
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page_cache_release(pages[page_nr]);
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pages[page_nr] = page;
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page_cache_release(spd.pages[page_nr]);
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spd.pages[page_nr] = page;
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}
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/*
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* page was already under io and is now done, great
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@ -451,8 +484,8 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
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len = this_len;
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}
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partial[page_nr].offset = loff;
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partial[page_nr].len = this_len;
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spd.partial[page_nr].offset = loff;
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spd.partial[page_nr].len = this_len;
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len -= this_len;
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loff = 0;
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spd.nr_pages++;
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@ -464,12 +497,13 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
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* we got, 'nr_pages' is how many pages are in the map.
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*/
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while (page_nr < nr_pages)
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page_cache_release(pages[page_nr++]);
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page_cache_release(spd.pages[page_nr++]);
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in->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
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if (spd.nr_pages)
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return splice_to_pipe(pipe, &spd);
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error = splice_to_pipe(pipe, &spd);
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splice_shrink_spd(pipe, &spd);
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return error;
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}
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@ -560,9 +594,9 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
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unsigned int nr_pages;
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unsigned int nr_freed;
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size_t offset;
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struct page *pages[PIPE_BUFFERS];
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struct partial_page partial[PIPE_BUFFERS];
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struct iovec vec[PIPE_BUFFERS];
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struct page *pages[PIPE_DEF_BUFFERS];
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struct partial_page partial[PIPE_DEF_BUFFERS];
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struct iovec *vec, __vec[PIPE_DEF_BUFFERS];
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pgoff_t index;
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ssize_t res;
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size_t this_len;
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@ -576,11 +610,22 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
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.spd_release = spd_release_page,
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};
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if (splice_grow_spd(pipe, &spd))
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return -ENOMEM;
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res = -ENOMEM;
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vec = __vec;
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if (pipe->buffers > PIPE_DEF_BUFFERS) {
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vec = kmalloc(pipe->buffers * sizeof(struct iovec), GFP_KERNEL);
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if (!vec)
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goto shrink_ret;
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}
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index = *ppos >> PAGE_CACHE_SHIFT;
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offset = *ppos & ~PAGE_CACHE_MASK;
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nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
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for (i = 0; i < nr_pages && i < PIPE_BUFFERS && len; i++) {
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for (i = 0; i < nr_pages && i < pipe->buffers && len; i++) {
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struct page *page;
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page = alloc_page(GFP_USER);
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@ -591,7 +636,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
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this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset);
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vec[i].iov_base = (void __user *) page_address(page);
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vec[i].iov_len = this_len;
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pages[i] = page;
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spd.pages[i] = page;
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spd.nr_pages++;
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len -= this_len;
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offset = 0;
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@ -610,11 +655,11 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
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nr_freed = 0;
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for (i = 0; i < spd.nr_pages; i++) {
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this_len = min_t(size_t, vec[i].iov_len, res);
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partial[i].offset = 0;
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partial[i].len = this_len;
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spd.partial[i].offset = 0;
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spd.partial[i].len = this_len;
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if (!this_len) {
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__free_page(pages[i]);
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pages[i] = NULL;
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__free_page(spd.pages[i]);
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spd.pages[i] = NULL;
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nr_freed++;
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}
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res -= this_len;
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@ -625,13 +670,18 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
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if (res > 0)
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*ppos += res;
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shrink_ret:
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if (vec != __vec)
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kfree(vec);
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splice_shrink_spd(pipe, &spd);
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return res;
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err:
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for (i = 0; i < spd.nr_pages; i++)
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__free_page(pages[i]);
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__free_page(spd.pages[i]);
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return error;
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res = error;
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goto shrink_ret;
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}
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EXPORT_SYMBOL(default_file_splice_read);
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|
||||
@ -784,7 +834,7 @@ int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd,
|
||||
if (!buf->len) {
|
||||
buf->ops = NULL;
|
||||
ops->release(pipe, buf);
|
||||
pipe->curbuf = (pipe->curbuf + 1) & (PIPE_BUFFERS - 1);
|
||||
pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
|
||||
pipe->nrbufs--;
|
||||
if (pipe->inode)
|
||||
sd->need_wakeup = true;
|
||||
@ -1211,7 +1261,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
|
||||
* If we did an incomplete transfer we must release
|
||||
* the pipe buffers in question:
|
||||
*/
|
||||
for (i = 0; i < PIPE_BUFFERS; i++) {
|
||||
for (i = 0; i < pipe->buffers; i++) {
|
||||
struct pipe_buffer *buf = pipe->bufs + i;
|
||||
|
||||
if (buf->ops) {
|
||||
@ -1371,7 +1421,8 @@ static long do_splice(struct file *in, loff_t __user *off_in,
|
||||
*/
|
||||
static int get_iovec_page_array(const struct iovec __user *iov,
|
||||
unsigned int nr_vecs, struct page **pages,
|
||||
struct partial_page *partial, int aligned)
|
||||
struct partial_page *partial, int aligned,
|
||||
unsigned int pipe_buffers)
|
||||
{
|
||||
int buffers = 0, error = 0;
|
||||
|
||||
@ -1414,8 +1465,8 @@ static int get_iovec_page_array(const struct iovec __user *iov,
|
||||
break;
|
||||
|
||||
npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
||||
if (npages > PIPE_BUFFERS - buffers)
|
||||
npages = PIPE_BUFFERS - buffers;
|
||||
if (npages > pipe_buffers - buffers)
|
||||
npages = pipe_buffers - buffers;
|
||||
|
||||
error = get_user_pages_fast((unsigned long)base, npages,
|
||||
0, &pages[buffers]);
|
||||
@ -1450,7 +1501,7 @@ static int get_iovec_page_array(const struct iovec __user *iov,
|
||||
* or if we mapped the max number of pages that we have
|
||||
* room for.
|
||||
*/
|
||||
if (error < npages || buffers == PIPE_BUFFERS)
|
||||
if (error < npages || buffers == pipe_buffers)
|
||||
break;
|
||||
|
||||
nr_vecs--;
|
||||
@ -1593,8 +1644,8 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
|
||||
unsigned long nr_segs, unsigned int flags)
|
||||
{
|
||||
struct pipe_inode_info *pipe;
|
||||
struct page *pages[PIPE_BUFFERS];
|
||||
struct partial_page partial[PIPE_BUFFERS];
|
||||
struct page *pages[PIPE_DEF_BUFFERS];
|
||||
struct partial_page partial[PIPE_DEF_BUFFERS];
|
||||
struct splice_pipe_desc spd = {
|
||||
.pages = pages,
|
||||
.partial = partial,
|
||||
@ -1602,17 +1653,25 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
|
||||
.ops = &user_page_pipe_buf_ops,
|
||||
.spd_release = spd_release_page,
|
||||
};
|
||||
long ret;
|
||||
|
||||
pipe = pipe_info(file->f_path.dentry->d_inode);
|
||||
if (!pipe)
|
||||
return -EBADF;
|
||||
|
||||
spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial,
|
||||
flags & SPLICE_F_GIFT);
|
||||
if (spd.nr_pages <= 0)
|
||||
return spd.nr_pages;
|
||||
if (splice_grow_spd(pipe, &spd))
|
||||
return -ENOMEM;
|
||||
|
||||
return splice_to_pipe(pipe, &spd);
|
||||
spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages,
|
||||
spd.partial, flags & SPLICE_F_GIFT,
|
||||
pipe->buffers);
|
||||
if (spd.nr_pages <= 0)
|
||||
ret = spd.nr_pages;
|
||||
else
|
||||
ret = splice_to_pipe(pipe, &spd);
|
||||
|
||||
splice_shrink_spd(pipe, &spd);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
@ -1738,13 +1797,13 @@ static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
|
||||
* Check ->nrbufs without the inode lock first. This function
|
||||
* is speculative anyways, so missing one is ok.
|
||||
*/
|
||||
if (pipe->nrbufs < PIPE_BUFFERS)
|
||||
if (pipe->nrbufs < pipe->buffers)
|
||||
return 0;
|
||||
|
||||
ret = 0;
|
||||
pipe_lock(pipe);
|
||||
|
||||
while (pipe->nrbufs >= PIPE_BUFFERS) {
|
||||
while (pipe->nrbufs >= pipe->buffers) {
|
||||
if (!pipe->readers) {
|
||||
send_sig(SIGPIPE, current, 0);
|
||||
ret = -EPIPE;
|
||||
@ -1810,7 +1869,7 @@ static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
|
||||
* Cannot make any progress, because either the input
|
||||
* pipe is empty or the output pipe is full.
|
||||
*/
|
||||
if (!ipipe->nrbufs || opipe->nrbufs >= PIPE_BUFFERS) {
|
||||
if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) {
|
||||
/* Already processed some buffers, break */
|
||||
if (ret)
|
||||
break;
|
||||
@ -1831,7 +1890,7 @@ static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
|
||||
}
|
||||
|
||||
ibuf = ipipe->bufs + ipipe->curbuf;
|
||||
nbuf = (opipe->curbuf + opipe->nrbufs) % PIPE_BUFFERS;
|
||||
nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
|
||||
obuf = opipe->bufs + nbuf;
|
||||
|
||||
if (len >= ibuf->len) {
|
||||
@ -1841,7 +1900,7 @@ static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
|
||||
*obuf = *ibuf;
|
||||
ibuf->ops = NULL;
|
||||
opipe->nrbufs++;
|
||||
ipipe->curbuf = (ipipe->curbuf + 1) % PIPE_BUFFERS;
|
||||
ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1);
|
||||
ipipe->nrbufs--;
|
||||
input_wakeup = true;
|
||||
} else {
|
||||
@ -1914,11 +1973,11 @@ static int link_pipe(struct pipe_inode_info *ipipe,
|
||||
* If we have iterated all input buffers or ran out of
|
||||
* output room, break.
|
||||
*/
|
||||
if (i >= ipipe->nrbufs || opipe->nrbufs >= PIPE_BUFFERS)
|
||||
if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers)
|
||||
break;
|
||||
|
||||
ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (PIPE_BUFFERS - 1));
|
||||
nbuf = (opipe->curbuf + opipe->nrbufs) & (PIPE_BUFFERS - 1);
|
||||
ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1));
|
||||
nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
|
||||
|
||||
/*
|
||||
* Get a reference to this pipe buffer,
|
||||
|
||||
@ -21,6 +21,12 @@
|
||||
*/
|
||||
#define F_NOTIFY (F_LINUX_SPECIFIC_BASE+2)
|
||||
|
||||
/*
|
||||
* Set and get of pipe page size array
|
||||
*/
|
||||
#define F_SETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 7)
|
||||
#define F_GETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 8)
|
||||
|
||||
/*
|
||||
* Types of directory notifications that may be requested.
|
||||
*/
|
||||
|
||||
@ -3,7 +3,7 @@
|
||||
|
||||
#define PIPEFS_MAGIC 0x50495045
|
||||
|
||||
#define PIPE_BUFFERS (16)
|
||||
#define PIPE_DEF_BUFFERS 16
|
||||
|
||||
#define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */
|
||||
#define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */
|
||||
@ -44,17 +44,17 @@ struct pipe_buffer {
|
||||
**/
|
||||
struct pipe_inode_info {
|
||||
wait_queue_head_t wait;
|
||||
unsigned int nrbufs, curbuf;
|
||||
struct page *tmp_page;
|
||||
unsigned int nrbufs, curbuf, buffers;
|
||||
unsigned int readers;
|
||||
unsigned int writers;
|
||||
unsigned int waiting_writers;
|
||||
unsigned int r_counter;
|
||||
unsigned int w_counter;
|
||||
struct page *tmp_page;
|
||||
struct fasync_struct *fasync_readers;
|
||||
struct fasync_struct *fasync_writers;
|
||||
struct inode *inode;
|
||||
struct pipe_buffer bufs[PIPE_BUFFERS];
|
||||
struct pipe_buffer *bufs;
|
||||
};
|
||||
|
||||
/*
|
||||
@ -154,4 +154,7 @@ int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *);
|
||||
int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);
|
||||
void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *);
|
||||
|
||||
/* for F_SETPIPE_SZ and F_GETPIPE_SZ */
|
||||
long pipe_fcntl(struct file *, unsigned int, unsigned long arg);
|
||||
|
||||
#endif
|
||||
|
||||
@ -82,4 +82,11 @@ extern ssize_t splice_to_pipe(struct pipe_inode_info *,
|
||||
extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
|
||||
splice_direct_actor *);
|
||||
|
||||
/*
|
||||
* for dynamic pipe sizing
|
||||
*/
|
||||
extern int splice_grow_spd(struct pipe_inode_info *, struct splice_pipe_desc *);
|
||||
extern void splice_shrink_spd(struct pipe_inode_info *,
|
||||
struct splice_pipe_desc *);
|
||||
|
||||
#endif
|
||||
|
||||
@ -1231,8 +1231,8 @@ static ssize_t subbuf_splice_actor(struct file *in,
|
||||
size_t read_subbuf = read_start / subbuf_size;
|
||||
size_t padding = rbuf->padding[read_subbuf];
|
||||
size_t nonpad_end = read_subbuf * subbuf_size + subbuf_size - padding;
|
||||
struct page *pages[PIPE_BUFFERS];
|
||||
struct partial_page partial[PIPE_BUFFERS];
|
||||
struct page *pages[PIPE_DEF_BUFFERS];
|
||||
struct partial_page partial[PIPE_DEF_BUFFERS];
|
||||
struct splice_pipe_desc spd = {
|
||||
.pages = pages,
|
||||
.nr_pages = 0,
|
||||
@ -1245,6 +1245,8 @@ static ssize_t subbuf_splice_actor(struct file *in,
|
||||
|
||||
if (rbuf->subbufs_produced == rbuf->subbufs_consumed)
|
||||
return 0;
|
||||
if (splice_grow_spd(pipe, &spd))
|
||||
return -ENOMEM;
|
||||
|
||||
/*
|
||||
* Adjust read len, if longer than what is available
|
||||
@ -1255,7 +1257,7 @@ static ssize_t subbuf_splice_actor(struct file *in,
|
||||
subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT;
|
||||
pidx = (read_start / PAGE_SIZE) % subbuf_pages;
|
||||
poff = read_start & ~PAGE_MASK;
|
||||
nr_pages = min_t(unsigned int, subbuf_pages, PIPE_BUFFERS);
|
||||
nr_pages = min_t(unsigned int, subbuf_pages, pipe->buffers);
|
||||
|
||||
for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) {
|
||||
unsigned int this_len, this_end, private;
|
||||
@ -1289,16 +1291,19 @@ static ssize_t subbuf_splice_actor(struct file *in,
|
||||
}
|
||||
}
|
||||
|
||||
ret = 0;
|
||||
if (!spd.nr_pages)
|
||||
return 0;
|
||||
goto out;
|
||||
|
||||
ret = *nonpad_ret = splice_to_pipe(pipe, &spd);
|
||||
if (ret < 0 || ret < total_len)
|
||||
return ret;
|
||||
goto out;
|
||||
|
||||
if (read_start + ret == nonpad_end)
|
||||
ret += padding;
|
||||
|
||||
out:
|
||||
splice_shrink_spd(pipe, &spd);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
@ -3269,12 +3269,12 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
|
||||
size_t len,
|
||||
unsigned int flags)
|
||||
{
|
||||
struct page *pages[PIPE_BUFFERS];
|
||||
struct partial_page partial[PIPE_BUFFERS];
|
||||
struct page *pages_def[PIPE_DEF_BUFFERS];
|
||||
struct partial_page partial_def[PIPE_DEF_BUFFERS];
|
||||
struct trace_iterator *iter = filp->private_data;
|
||||
struct splice_pipe_desc spd = {
|
||||
.pages = pages,
|
||||
.partial = partial,
|
||||
.pages = pages_def,
|
||||
.partial = partial_def,
|
||||
.nr_pages = 0, /* This gets updated below. */
|
||||
.flags = flags,
|
||||
.ops = &tracing_pipe_buf_ops,
|
||||
@ -3285,6 +3285,9 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
|
||||
size_t rem;
|
||||
unsigned int i;
|
||||
|
||||
if (splice_grow_spd(pipe, &spd))
|
||||
return -ENOMEM;
|
||||
|
||||
/* copy the tracer to avoid using a global lock all around */
|
||||
mutex_lock(&trace_types_lock);
|
||||
if (unlikely(old_tracer != current_trace && current_trace)) {
|
||||
@ -3315,23 +3318,23 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
|
||||
trace_access_lock(iter->cpu_file);
|
||||
|
||||
/* Fill as many pages as possible. */
|
||||
for (i = 0, rem = len; i < PIPE_BUFFERS && rem; i++) {
|
||||
pages[i] = alloc_page(GFP_KERNEL);
|
||||
if (!pages[i])
|
||||
for (i = 0, rem = len; i < pipe->buffers && rem; i++) {
|
||||
spd.pages[i] = alloc_page(GFP_KERNEL);
|
||||
if (!spd.pages[i])
|
||||
break;
|
||||
|
||||
rem = tracing_fill_pipe_page(rem, iter);
|
||||
|
||||
/* Copy the data into the page, so we can start over. */
|
||||
ret = trace_seq_to_buffer(&iter->seq,
|
||||
page_address(pages[i]),
|
||||
page_address(spd.pages[i]),
|
||||
iter->seq.len);
|
||||
if (ret < 0) {
|
||||
__free_page(pages[i]);
|
||||
__free_page(spd.pages[i]);
|
||||
break;
|
||||
}
|
||||
partial[i].offset = 0;
|
||||
partial[i].len = iter->seq.len;
|
||||
spd.partial[i].offset = 0;
|
||||
spd.partial[i].len = iter->seq.len;
|
||||
|
||||
trace_seq_init(&iter->seq);
|
||||
}
|
||||
@ -3342,12 +3345,14 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
|
||||
|
||||
spd.nr_pages = i;
|
||||
|
||||
return splice_to_pipe(pipe, &spd);
|
||||
ret = splice_to_pipe(pipe, &spd);
|
||||
out:
|
||||
splice_shrink_spd(pipe, &spd);
|
||||
return ret;
|
||||
|
||||
out_err:
|
||||
mutex_unlock(&iter->mutex);
|
||||
|
||||
return ret;
|
||||
goto out;
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
@ -3746,11 +3751,11 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
|
||||
unsigned int flags)
|
||||
{
|
||||
struct ftrace_buffer_info *info = file->private_data;
|
||||
struct partial_page partial[PIPE_BUFFERS];
|
||||
struct page *pages[PIPE_BUFFERS];
|
||||
struct partial_page partial_def[PIPE_DEF_BUFFERS];
|
||||
struct page *pages_def[PIPE_DEF_BUFFERS];
|
||||
struct splice_pipe_desc spd = {
|
||||
.pages = pages,
|
||||
.partial = partial,
|
||||
.pages = pages_def,
|
||||
.partial = partial_def,
|
||||
.flags = flags,
|
||||
.ops = &buffer_pipe_buf_ops,
|
||||
.spd_release = buffer_spd_release,
|
||||
@ -3759,22 +3764,28 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
|
||||
int entries, size, i;
|
||||
size_t ret;
|
||||
|
||||
if (splice_grow_spd(pipe, &spd))
|
||||
return -ENOMEM;
|
||||
|
||||
if (*ppos & (PAGE_SIZE - 1)) {
|
||||
WARN_ONCE(1, "Ftrace: previous read must page-align\n");
|
||||
return -EINVAL;
|
||||
ret = -EINVAL;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (len & (PAGE_SIZE - 1)) {
|
||||
WARN_ONCE(1, "Ftrace: splice_read should page-align\n");
|
||||
if (len < PAGE_SIZE)
|
||||
return -EINVAL;
|
||||
if (len < PAGE_SIZE) {
|
||||
ret = -EINVAL;
|
||||
goto out;
|
||||
}
|
||||
len &= PAGE_MASK;
|
||||
}
|
||||
|
||||
trace_access_lock(info->cpu);
|
||||
entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu);
|
||||
|
||||
for (i = 0; i < PIPE_BUFFERS && len && entries; i++, len -= PAGE_SIZE) {
|
||||
for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) {
|
||||
struct page *page;
|
||||
int r;
|
||||
|
||||
@ -3829,11 +3840,12 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
|
||||
else
|
||||
ret = 0;
|
||||
/* TODO: block */
|
||||
return ret;
|
||||
goto out;
|
||||
}
|
||||
|
||||
ret = splice_to_pipe(pipe, &spd);
|
||||
|
||||
splice_shrink_spd(pipe, &spd);
|
||||
out:
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
@ -1417,12 +1417,13 @@ static inline struct page *linear_to_page(struct page *page, unsigned int *len,
|
||||
/*
|
||||
* Fill page/offset/length into spd, if it can hold more pages.
|
||||
*/
|
||||
static inline int spd_fill_page(struct splice_pipe_desc *spd, struct page *page,
|
||||
static inline int spd_fill_page(struct splice_pipe_desc *spd,
|
||||
struct pipe_inode_info *pipe, struct page *page,
|
||||
unsigned int *len, unsigned int offset,
|
||||
struct sk_buff *skb, int linear,
|
||||
struct sock *sk)
|
||||
{
|
||||
if (unlikely(spd->nr_pages == PIPE_BUFFERS))
|
||||
if (unlikely(spd->nr_pages == pipe->buffers))
|
||||
return 1;
|
||||
|
||||
if (linear) {
|
||||
@ -1458,7 +1459,8 @@ static inline int __splice_segment(struct page *page, unsigned int poff,
|
||||
unsigned int plen, unsigned int *off,
|
||||
unsigned int *len, struct sk_buff *skb,
|
||||
struct splice_pipe_desc *spd, int linear,
|
||||
struct sock *sk)
|
||||
struct sock *sk,
|
||||
struct pipe_inode_info *pipe)
|
||||
{
|
||||
if (!*len)
|
||||
return 1;
|
||||
@ -1481,7 +1483,7 @@ static inline int __splice_segment(struct page *page, unsigned int poff,
|
||||
/* the linear region may spread across several pages */
|
||||
flen = min_t(unsigned int, flen, PAGE_SIZE - poff);
|
||||
|
||||
if (spd_fill_page(spd, page, &flen, poff, skb, linear, sk))
|
||||
if (spd_fill_page(spd, pipe, page, &flen, poff, skb, linear, sk))
|
||||
return 1;
|
||||
|
||||
__segment_seek(&page, &poff, &plen, flen);
|
||||
@ -1496,9 +1498,9 @@ static inline int __splice_segment(struct page *page, unsigned int poff,
|
||||
* Map linear and fragment data from the skb to spd. It reports failure if the
|
||||
* pipe is full or if we already spliced the requested length.
|
||||
*/
|
||||
static int __skb_splice_bits(struct sk_buff *skb, unsigned int *offset,
|
||||
unsigned int *len, struct splice_pipe_desc *spd,
|
||||
struct sock *sk)
|
||||
static int __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
|
||||
unsigned int *offset, unsigned int *len,
|
||||
struct splice_pipe_desc *spd, struct sock *sk)
|
||||
{
|
||||
int seg;
|
||||
|
||||
@ -1508,7 +1510,7 @@ static int __skb_splice_bits(struct sk_buff *skb, unsigned int *offset,
|
||||
if (__splice_segment(virt_to_page(skb->data),
|
||||
(unsigned long) skb->data & (PAGE_SIZE - 1),
|
||||
skb_headlen(skb),
|
||||
offset, len, skb, spd, 1, sk))
|
||||
offset, len, skb, spd, 1, sk, pipe))
|
||||
return 1;
|
||||
|
||||
/*
|
||||
@ -1518,7 +1520,7 @@ static int __skb_splice_bits(struct sk_buff *skb, unsigned int *offset,
|
||||
const skb_frag_t *f = &skb_shinfo(skb)->frags[seg];
|
||||
|
||||
if (__splice_segment(f->page, f->page_offset, f->size,
|
||||
offset, len, skb, spd, 0, sk))
|
||||
offset, len, skb, spd, 0, sk, pipe))
|
||||
return 1;
|
||||
}
|
||||
|
||||
@ -1535,8 +1537,8 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
|
||||
struct pipe_inode_info *pipe, unsigned int tlen,
|
||||
unsigned int flags)
|
||||
{
|
||||
struct partial_page partial[PIPE_BUFFERS];
|
||||
struct page *pages[PIPE_BUFFERS];
|
||||
struct partial_page partial[PIPE_DEF_BUFFERS];
|
||||
struct page *pages[PIPE_DEF_BUFFERS];
|
||||
struct splice_pipe_desc spd = {
|
||||
.pages = pages,
|
||||
.partial = partial,
|
||||
@ -1546,12 +1548,16 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
|
||||
};
|
||||
struct sk_buff *frag_iter;
|
||||
struct sock *sk = skb->sk;
|
||||
int ret = 0;
|
||||
|
||||
if (splice_grow_spd(pipe, &spd))
|
||||
return -ENOMEM;
|
||||
|
||||
/*
|
||||
* __skb_splice_bits() only fails if the output has no room left,
|
||||
* so no point in going over the frag_list for the error case.
|
||||
*/
|
||||
if (__skb_splice_bits(skb, &offset, &tlen, &spd, sk))
|
||||
if (__skb_splice_bits(skb, pipe, &offset, &tlen, &spd, sk))
|
||||
goto done;
|
||||
else if (!tlen)
|
||||
goto done;
|
||||
@ -1562,14 +1568,12 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
|
||||
skb_walk_frags(skb, frag_iter) {
|
||||
if (!tlen)
|
||||
break;
|
||||
if (__skb_splice_bits(frag_iter, &offset, &tlen, &spd, sk))
|
||||
if (__skb_splice_bits(frag_iter, pipe, &offset, &tlen, &spd, sk))
|
||||
break;
|
||||
}
|
||||
|
||||
done:
|
||||
if (spd.nr_pages) {
|
||||
int ret;
|
||||
|
||||
/*
|
||||
* Drop the socket lock, otherwise we have reverse
|
||||
* locking dependencies between sk_lock and i_mutex
|
||||
@ -1582,10 +1586,10 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
|
||||
release_sock(sk);
|
||||
ret = splice_to_pipe(pipe, &spd);
|
||||
lock_sock(sk);
|
||||
return ret;
|
||||
}
|
||||
|
||||
return 0;
|
||||
splice_shrink_spd(pipe, &spd);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
|
||||
Loading…
Reference in New Issue
Block a user