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@@ -1,153 +0,0 @@
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-/*
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- * linux/fs/fifo.c
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- *
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- * written by Paul H. Hargrove
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- *
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- * Fixes:
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- * 10-06-1999, AV: fixed OOM handling in fifo_open(), moved
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- * initialization there, switched to external
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- * allocation of pipe_inode_info.
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- */
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-
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-#include <linux/mm.h>
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-#include <linux/fs.h>
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-#include <linux/sched.h>
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-#include <linux/pipe_fs_i.h>
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-
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-static int wait_for_partner(struct inode* inode, unsigned int *cnt)
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-{
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- int cur = *cnt;
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-
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- while (cur == *cnt) {
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- pipe_wait(inode->i_pipe);
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- if (signal_pending(current))
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- break;
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- }
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- return cur == *cnt ? -ERESTARTSYS : 0;
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-}
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-
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-static void wake_up_partner(struct inode* inode)
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-{
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- wake_up_interruptible(&inode->i_pipe->wait);
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-}
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-
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-static int fifo_open(struct inode *inode, struct file *filp)
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-{
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- struct pipe_inode_info *pipe;
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- int ret;
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-
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- mutex_lock(&inode->i_mutex);
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- pipe = inode->i_pipe;
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- if (!pipe) {
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- ret = -ENOMEM;
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- pipe = alloc_pipe_info(inode);
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- if (!pipe)
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- goto err_nocleanup;
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- inode->i_pipe = pipe;
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- }
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- filp->f_version = 0;
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-
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- /* We can only do regular read/write on fifos */
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- filp->f_mode &= (FMODE_READ | FMODE_WRITE);
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-
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- switch (filp->f_mode) {
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- case FMODE_READ:
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- /*
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- * O_RDONLY
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- * POSIX.1 says that O_NONBLOCK means return with the FIFO
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- * opened, even when there is no process writing the FIFO.
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- */
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- filp->f_op = &read_pipefifo_fops;
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- pipe->r_counter++;
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- if (pipe->readers++ == 0)
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- wake_up_partner(inode);
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-
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- if (!pipe->writers) {
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- if ((filp->f_flags & O_NONBLOCK)) {
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- /* suppress POLLHUP until we have
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- * seen a writer */
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- filp->f_version = pipe->w_counter;
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- } else {
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- if (wait_for_partner(inode, &pipe->w_counter))
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- goto err_rd;
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- }
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- }
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- break;
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-
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- case FMODE_WRITE:
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- /*
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- * O_WRONLY
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- * POSIX.1 says that O_NONBLOCK means return -1 with
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- * errno=ENXIO when there is no process reading the FIFO.
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- */
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- ret = -ENXIO;
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- if ((filp->f_flags & O_NONBLOCK) && !pipe->readers)
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- goto err;
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-
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- filp->f_op = &write_pipefifo_fops;
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- pipe->w_counter++;
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- if (!pipe->writers++)
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- wake_up_partner(inode);
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-
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- if (!pipe->readers) {
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- if (wait_for_partner(inode, &pipe->r_counter))
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- goto err_wr;
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- }
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- break;
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-
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- case FMODE_READ | FMODE_WRITE:
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- /*
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- * O_RDWR
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- * POSIX.1 leaves this case "undefined" when O_NONBLOCK is set.
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- * This implementation will NEVER block on a O_RDWR open, since
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- * the process can at least talk to itself.
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- */
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- filp->f_op = &rdwr_pipefifo_fops;
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-
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- pipe->readers++;
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- pipe->writers++;
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- pipe->r_counter++;
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- pipe->w_counter++;
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- if (pipe->readers == 1 || pipe->writers == 1)
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- wake_up_partner(inode);
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- break;
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-
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- default:
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- ret = -EINVAL;
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- goto err;
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- }
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-
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- /* Ok! */
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- mutex_unlock(&inode->i_mutex);
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- return 0;
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-
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-err_rd:
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- if (!--pipe->readers)
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- wake_up_interruptible(&pipe->wait);
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- ret = -ERESTARTSYS;
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- goto err;
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-
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-err_wr:
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- if (!--pipe->writers)
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- wake_up_interruptible(&pipe->wait);
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- ret = -ERESTARTSYS;
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- goto err;
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-
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-err:
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- if (!pipe->readers && !pipe->writers)
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- free_pipe_info(inode);
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-
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-err_nocleanup:
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- mutex_unlock(&inode->i_mutex);
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- return ret;
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-}
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-
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-/*
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- * Dummy default file-operations: the only thing this does
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- * is contain the open that then fills in the correct operations
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- * depending on the access mode of the file...
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- */
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-const struct file_operations def_fifo_fops = {
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- .open = fifo_open, /* will set read_ or write_pipefifo_fops */
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- .llseek = noop_llseek,
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-};
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