Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/fs/fifo.c b/fs/fifo.c
new file mode 100644
index 0000000..5455916
--- /dev/null
+++ b/fs/fifo.c
@@ -0,0 +1,155 @@
+/*
+ * linux/fs/fifo.c
+ *
+ * written by Paul H. Hargrove
+ *
+ * Fixes:
+ * 10-06-1999, AV: fixed OOM handling in fifo_open(), moved
+ * initialization there, switched to external
+ * allocation of pipe_inode_info.
+ */
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/fs.h>
+#include <linux/pipe_fs_i.h>
+
+static void wait_for_partner(struct inode* inode, unsigned int* cnt)
+{
+ int cur = *cnt;
+ while(cur == *cnt) {
+ pipe_wait(inode);
+ if(signal_pending(current))
+ break;
+ }
+}
+
+static void wake_up_partner(struct inode* inode)
+{
+ wake_up_interruptible(PIPE_WAIT(*inode));
+}
+
+static int fifo_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+
+ ret = -ERESTARTSYS;
+ if (down_interruptible(PIPE_SEM(*inode)))
+ goto err_nolock_nocleanup;
+
+ if (!inode->i_pipe) {
+ ret = -ENOMEM;
+ if(!pipe_new(inode))
+ goto err_nocleanup;
+ }
+ filp->f_version = 0;
+
+ /* We can only do regular read/write on fifos */
+ filp->f_mode &= (FMODE_READ | FMODE_WRITE);
+
+ switch (filp->f_mode) {
+ case 1:
+ /*
+ * O_RDONLY
+ * POSIX.1 says that O_NONBLOCK means return with the FIFO
+ * opened, even when there is no process writing the FIFO.
+ */
+ filp->f_op = &read_fifo_fops;
+ PIPE_RCOUNTER(*inode)++;
+ if (PIPE_READERS(*inode)++ == 0)
+ wake_up_partner(inode);
+
+ if (!PIPE_WRITERS(*inode)) {
+ if ((filp->f_flags & O_NONBLOCK)) {
+ /* suppress POLLHUP until we have
+ * seen a writer */
+ filp->f_version = PIPE_WCOUNTER(*inode);
+ } else
+ {
+ wait_for_partner(inode, &PIPE_WCOUNTER(*inode));
+ if(signal_pending(current))
+ goto err_rd;
+ }
+ }
+ break;
+
+ case 2:
+ /*
+ * O_WRONLY
+ * POSIX.1 says that O_NONBLOCK means return -1 with
+ * errno=ENXIO when there is no process reading the FIFO.
+ */
+ ret = -ENXIO;
+ if ((filp->f_flags & O_NONBLOCK) && !PIPE_READERS(*inode))
+ goto err;
+
+ filp->f_op = &write_fifo_fops;
+ PIPE_WCOUNTER(*inode)++;
+ if (!PIPE_WRITERS(*inode)++)
+ wake_up_partner(inode);
+
+ if (!PIPE_READERS(*inode)) {
+ wait_for_partner(inode, &PIPE_RCOUNTER(*inode));
+ if (signal_pending(current))
+ goto err_wr;
+ }
+ break;
+
+ case 3:
+ /*
+ * O_RDWR
+ * POSIX.1 leaves this case "undefined" when O_NONBLOCK is set.
+ * This implementation will NEVER block on a O_RDWR open, since
+ * the process can at least talk to itself.
+ */
+ filp->f_op = &rdwr_fifo_fops;
+
+ PIPE_READERS(*inode)++;
+ PIPE_WRITERS(*inode)++;
+ PIPE_RCOUNTER(*inode)++;
+ PIPE_WCOUNTER(*inode)++;
+ if (PIPE_READERS(*inode) == 1 || PIPE_WRITERS(*inode) == 1)
+ wake_up_partner(inode);
+ break;
+
+ default:
+ ret = -EINVAL;
+ goto err;
+ }
+
+ /* Ok! */
+ up(PIPE_SEM(*inode));
+ return 0;
+
+err_rd:
+ if (!--PIPE_READERS(*inode))
+ wake_up_interruptible(PIPE_WAIT(*inode));
+ ret = -ERESTARTSYS;
+ goto err;
+
+err_wr:
+ if (!--PIPE_WRITERS(*inode))
+ wake_up_interruptible(PIPE_WAIT(*inode));
+ ret = -ERESTARTSYS;
+ goto err;
+
+err:
+ if (!PIPE_READERS(*inode) && !PIPE_WRITERS(*inode))
+ free_pipe_info(inode);
+
+err_nocleanup:
+ up(PIPE_SEM(*inode));
+
+err_nolock_nocleanup:
+ return ret;
+}
+
+/*
+ * Dummy default file-operations: the only thing this does
+ * is contain the open that then fills in the correct operations
+ * depending on the access mode of the file...
+ */
+struct file_operations def_fifo_fops = {
+ .open = fifo_open, /* will set read or write pipe_fops */
+};