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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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[PATCH] another round of fs/pipe.c cleanups
make pipe.c a bit more readable and hackable. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jens Axboe <axboe@suse.de>
This commit is contained in:
Ingo Molnar
Jens Axboe
parent
73d62d83ec
commit
341b446bc5
76
fs/pipe.c
76
fs/pipe.c
@ -44,7 +44,8 @@ void pipe_wait(struct pipe_inode_info *pipe)
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* Pipes are system-local resources, so sleeping on them
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* is considered a noninteractive wait:
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*/
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prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE);
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prepare_to_wait(&pipe->wait, &wait,
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TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE);
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if (pipe->inode)
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mutex_unlock(&pipe->inode->i_mutex);
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schedule();
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@ -93,7 +94,8 @@ pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len)
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return 0;
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}
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static void anon_pipe_buf_release(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
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static void anon_pipe_buf_release(struct pipe_inode_info *pipe,
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struct pipe_buffer *buf)
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{
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struct page *page = buf->page;
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@ -102,25 +104,22 @@ static void anon_pipe_buf_release(struct pipe_inode_info *pipe, struct pipe_buff
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/*
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* If nobody else uses this page, and we don't already have a
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* temporary page, let's keep track of it as a one-deep
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* allocation cache
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* allocation cache. (Otherwise just release our reference to it)
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*/
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if (page_count(page) == 1 && !pipe->tmp_page) {
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if (page_count(page) == 1 && !pipe->tmp_page)
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pipe->tmp_page = page;
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return;
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}
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/*
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* Otherwise just release our reference to it
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*/
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page_cache_release(page);
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else
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page_cache_release(page);
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}
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static void *anon_pipe_buf_map(struct file *file, struct pipe_inode_info *pipe, struct pipe_buffer *buf)
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static void * anon_pipe_buf_map(struct file *file, struct pipe_inode_info *pipe,
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struct pipe_buffer *buf)
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{
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return kmap(buf->page);
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}
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static void anon_pipe_buf_unmap(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
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static void anon_pipe_buf_unmap(struct pipe_inode_info *pipe,
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struct pipe_buffer *buf)
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{
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kunmap(buf->page);
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}
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@ -182,7 +181,8 @@ pipe_readv(struct file *filp, const struct iovec *_iov,
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error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars);
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ops->unmap(pipe, buf);
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if (unlikely(error)) {
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if (!ret) ret = -EFAULT;
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if (!ret)
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ret = -EFAULT;
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break;
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}
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ret += chars;
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@ -218,7 +218,8 @@ pipe_readv(struct file *filp, const struct iovec *_iov,
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}
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}
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if (signal_pending(current)) {
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if (!ret) ret = -ERESTARTSYS;
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if (!ret)
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ret = -ERESTARTSYS;
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break;
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}
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if (do_wakeup) {
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@ -228,7 +229,8 @@ pipe_readv(struct file *filp, const struct iovec *_iov,
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pipe_wait(pipe);
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}
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mutex_unlock(&inode->i_mutex);
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/* Signal writers asynchronously that there is more room. */
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/* Signal writers asynchronously that there is more room. */
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if (do_wakeup) {
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wake_up_interruptible(&pipe->wait);
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kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
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@ -242,6 +244,7 @@ static ssize_t
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pipe_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
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{
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struct iovec iov = { .iov_base = buf, .iov_len = count };
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return pipe_readv(filp, &iov, 1, ppos);
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}
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@ -276,10 +279,12 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
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/* We try to merge small writes */
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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) & (PIPE_BUFFERS-1);
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int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) &
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(PIPE_BUFFERS-1);
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struct pipe_buffer *buf = pipe->bufs + lastbuf;
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struct pipe_buf_operations *ops = buf->ops;
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int offset = buf->offset + buf->len;
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if (ops->can_merge && offset + chars <= PAGE_SIZE) {
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void *addr;
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int error;
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@ -306,9 +311,11 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
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for (;;) {
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int bufs;
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if (!pipe->readers) {
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send_sig(SIGPIPE, current, 0);
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if (!ret) ret = -EPIPE;
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if (!ret)
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ret = -EPIPE;
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break;
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}
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bufs = pipe->nrbufs;
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@ -326,7 +333,7 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
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}
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pipe->tmp_page = page;
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}
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/* Always wakeup, even if the copy fails. Otherwise
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/* Always wake up, even if the copy fails. Otherwise
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* we lock up (O_NONBLOCK-)readers that sleep due to
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* syscall merging.
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* FIXME! Is this really true?
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@ -339,7 +346,8 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
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error = pipe_iov_copy_from_user(kmap(page), iov, chars);
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kunmap(page);
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if (unlikely(error)) {
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if (!ret) ret = -EFAULT;
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if (!ret)
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ret = -EFAULT;
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break;
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}
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ret += chars;
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@ -359,11 +367,13 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
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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) ret = -EAGAIN;
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if (!ret)
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ret = -EAGAIN;
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break;
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}
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if (signal_pending(current)) {
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if (!ret) ret = -ERESTARTSYS;
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if (!ret)
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ret = -ERESTARTSYS;
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break;
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}
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if (do_wakeup) {
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@ -391,6 +401,7 @@ pipe_write(struct file *filp, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
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return pipe_writev(filp, &iov, 1, ppos);
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}
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@ -401,7 +412,8 @@ bad_pipe_r(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
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}
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static ssize_t
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bad_pipe_w(struct file *filp, const char __user *buf, size_t count, loff_t *ppos)
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bad_pipe_w(struct file *filp, const char __user *buf, size_t count,
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loff_t *ppos)
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{
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return -EBADF;
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}
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@ -475,6 +487,7 @@ pipe_release(struct inode *inode, int decr, int decw)
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pipe = inode->i_pipe;
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pipe->readers -= decr;
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pipe->writers -= decw;
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if (!pipe->readers && !pipe->writers) {
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free_pipe_info(inode);
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} else {
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@ -525,14 +538,15 @@ static int
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pipe_rdwr_fasync(int fd, struct file *filp, int on)
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{
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struct inode *inode = filp->f_dentry->d_inode;
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struct pipe_inode_info *pipe = inode->i_pipe;
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int retval;
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mutex_lock(&inode->i_mutex);
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retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers);
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retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);
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if (retval >= 0)
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retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers);
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retval = fasync_helper(fd, filp, on, &pipe->fasync_writers);
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mutex_unlock(&inode->i_mutex);
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@ -720,6 +734,7 @@ static int pipefs_delete_dentry(struct dentry *dentry)
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{
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return 1;
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}
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static struct dentry_operations pipefs_dentry_operations = {
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.d_delete = pipefs_delete_dentry,
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};
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@ -757,6 +772,7 @@ static struct inode * get_pipe_inode(void)
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fail_iput:
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iput(inode);
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fail_inode:
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return NULL;
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}
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@ -769,7 +785,7 @@ int do_pipe(int *fd)
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struct inode * inode;
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struct file *f1, *f2;
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int error;
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int i,j;
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int i, j;
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error = -ENFILE;
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f1 = get_empty_filp();
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@ -802,6 +818,7 @@ int do_pipe(int *fd)
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dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &this);
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if (!dentry)
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goto close_f12_inode_i_j;
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dentry->d_op = &pipefs_dentry_operations;
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d_add(dentry, inode);
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f1->f_vfsmnt = f2->f_vfsmnt = mntget(mntget(pipe_mnt));
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@ -825,6 +842,7 @@ int do_pipe(int *fd)
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fd_install(j, f2);
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fd[0] = i;
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fd[1] = j;
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return 0;
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close_f12_inode_i_j:
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@ -849,8 +867,9 @@ int do_pipe(int *fd)
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* d_name - pipe: will go nicely and kill the special-casing in procfs.
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*/
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static struct super_block *pipefs_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data)
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static struct super_block *
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pipefs_get_sb(struct file_system_type *fs_type, int flags,
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const char *dev_name, void *data)
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{
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return get_sb_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC);
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}
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@ -864,6 +883,7 @@ static struct file_system_type pipe_fs_type = {
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static int __init init_pipe_fs(void)
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{
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int err = register_filesystem(&pipe_fs_type);
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if (!err) {
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pipe_mnt = kern_mount(&pipe_fs_type);
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if (IS_ERR(pipe_mnt)) {
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