Import of Linux/MIPS 1.3.0

1 files changed, 145 insertions, 0 deletions

diff --git a/fs/readdir.c b/fs/readdir.c
new file mode 100644
index 000000000..9a4160ac6
--- /dev/null
+++ b/fs/readdir.c
@@ -0,0 +1,145 @@
+/*
+ *  linux/fs/readdir.c
+ *
+ *  Copyright (C) 1995  Linus Torvalds
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+
+#include <asm/segment.h>
+
+/*
+ * Traditional linux readdir() handling..
+ *
+ * "count=1" is a special case, meaning that the buffer is one
+ * dirent-structure in size and that the code can't handle more
+ * anyway. Thus the special "fillonedir()" function for that
+ * case (the low-level handlers don't need to care about this).
+ */
+#define NAME_OFFSET(de) ((int) ((de)->d_name - (char *) (de)))
+#define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1))
+
+struct old_linux_dirent {
+	unsigned long	d_ino;
+	unsigned long	d_offset;
+	unsigned short	d_namlen;
+	char		d_name[1];
+};
+
+struct readdir_callback {
+	struct old_linux_dirent * dirent;
+	int count;
+};
+
+static int fillonedir(void * __buf, char * name, int namlen, off_t offset, ino_t ino)
+{
+	struct readdir_callback * buf = (struct readdir_callback *) __buf;
+	struct old_linux_dirent * dirent;
+
+	if (buf->count)
+		return -EINVAL;
+	buf->count++;
+	dirent = buf->dirent;
+	put_fs_long(ino, &dirent->d_ino);
+	put_fs_long(offset, &dirent->d_offset);
+	put_fs_word(namlen, &dirent->d_namlen);
+	memcpy_tofs(dirent->d_name, name, namlen);
+	put_fs_byte(0, dirent->d_name + namlen);
+	return 0;
+}
+
+asmlinkage int old_readdir(unsigned int fd, void * dirent, unsigned int count)
+{
+	int error;
+	struct file * file;
+	struct readdir_callback buf;
+
+	if (fd >= NR_OPEN || !(file = current->files->fd[fd]))
+		return -EBADF;
+	if (!file->f_op || !file->f_op->readdir)
+		return -ENOTDIR;
+	error = verify_area(VERIFY_WRITE, dirent, sizeof(struct old_linux_dirent));
+	if (error)
+		return error;
+	buf.count = 0;
+	buf.dirent = dirent;
+	error = file->f_op->readdir(file->f_inode, file, &buf, fillonedir);
+	if (error < 0)
+		return error;
+	return buf.count;
+}
+
+/*
+ * New, all-improved, singing, dancing, iBCS2-compliant getdents()
+ * interface. 
+ */
+struct linux_dirent {
+	unsigned long	d_ino;
+	unsigned long	d_off;
+	unsigned short	d_reclen;
+	char		d_name[1];
+};
+
+struct getdents_callback {
+	struct linux_dirent * current;
+	struct linux_dirent * previous;
+	int count;
+	int error;
+};
+
+static int filldir(void * __buf, char * name, int namlen, off_t offset, ino_t ino)
+{
+	struct linux_dirent * dirent;
+	struct getdents_callback * buf = (struct getdents_callback *) __buf;
+	int reclen = ROUND_UP(NAME_OFFSET(dirent) + namlen + 1);
+
+	buf->error = -EINVAL;	/* only used if we fail.. */
+	if (reclen > buf->count)
+		return -EINVAL;
+	dirent = buf->previous;
+	if (dirent)
+		put_user(offset, &dirent->d_off);
+	dirent = buf->current;
+	buf->previous = dirent;
+	put_fs_long(ino, &dirent->d_ino);
+	put_fs_word(reclen, &dirent->d_reclen);
+	memcpy_tofs(dirent->d_name, name, namlen);
+	put_fs_byte(0, dirent->d_name + namlen);
+	((char *) dirent) += reclen;
+	buf->current = dirent;
+	buf->count -= reclen;
+	return 0;
+}
+
+asmlinkage int sys_getdents(unsigned int fd, void * dirent, unsigned int count)
+{
+	struct file * file;
+	struct linux_dirent * lastdirent;
+	struct getdents_callback buf;
+	int error;
+
+	if (fd >= NR_OPEN || !(file = current->files->fd[fd]))
+		return -EBADF;
+	if (!file->f_op || !file->f_op->readdir)
+		return -ENOTDIR;
+	error = verify_area(VERIFY_WRITE, dirent, count);
+	if (error)
+		return error;
+	buf.current = (struct linux_dirent *) dirent;
+	buf.previous = NULL;
+	buf.count = count;
+	buf.error = 0;
+	error = file->f_op->readdir(file->f_inode, file, &buf, filldir);
+	if (error < 0)
+		return error;
+	lastdirent = buf.previous;
+	if (!lastdirent)
+		return buf.error;
+	put_user(file->f_pos, &lastdirent->d_off);
+	return count - buf.count;
+}