1 files changed, 230 insertions, 0 deletions
diff --git a/fs/coda/file.c b/fs/coda/file.c
new file mode 100644
index 000000000..1da3805f3
--- /dev/null
+++ b/fs/coda/file.c
@@ -0,0 +1,230 @@
+/*
+ * File operations for Coda.
+ * Original version: (C) 1996 Peter Braam 
+ * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
+ *
+ * Carnegie Mellon encourages users of this code to contribute improvements
+ * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/cred.h>
+#include <linux/errno.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <linux/coda.h>
+#include <linux/coda_psdev.h>
+
+#include "coda_linux.h"
+#include "coda_int.h"
+
+static ssize_t
+coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct file *coda_file = iocb->ki_filp;
+	struct coda_file_info *cfi = CODA_FTOC(coda_file);
+
+	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
+
+	return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos);
+}
+
+static ssize_t
+coda_file_splice_read(struct file *coda_file, loff_t *ppos,
+		      struct pipe_inode_info *pipe, size_t count,
+		      unsigned int flags)
+{
+	ssize_t (*splice_read)(struct file *, loff_t *,
+			       struct pipe_inode_info *, size_t, unsigned int);
+	struct coda_file_info *cfi;
+	struct file *host_file;
+
+	cfi = CODA_FTOC(coda_file);
+	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
+	host_file = cfi->cfi_container;
+
+	splice_read = host_file->f_op->splice_read;
+	if (!splice_read)
+		splice_read = default_file_splice_read;
+
+	return splice_read(host_file, ppos, pipe, count, flags);
+}
+
+static ssize_t
+coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct file *coda_file = iocb->ki_filp;
+	struct inode *coda_inode = file_inode(coda_file);
+	struct coda_file_info *cfi = CODA_FTOC(coda_file);
+	struct file *host_file;
+	ssize_t ret;
+
+	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
+
+	host_file = cfi->cfi_container;
+	file_start_write(host_file);
+	mutex_lock(&coda_inode->i_mutex);
+	ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos);
+	coda_inode->i_size = file_inode(host_file)->i_size;
+	coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
+	coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
+	mutex_unlock(&coda_inode->i_mutex);
+	file_end_write(host_file);
+	return ret;
+}
+
+static int
+coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
+{
+	struct coda_file_info *cfi;
+	struct coda_inode_info *cii;
+	struct file *host_file;
+	struct inode *coda_inode, *host_inode;
+
+	cfi = CODA_FTOC(coda_file);
+	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
+	host_file = cfi->cfi_container;
+
+	if (!host_file->f_op->mmap)
+		return -ENODEV;
+
+	coda_inode = file_inode(coda_file);
+	host_inode = file_inode(host_file);
+
+	cii = ITOC(coda_inode);
+	spin_lock(&cii->c_lock);
+	coda_file->f_mapping = host_file->f_mapping;
+	if (coda_inode->i_mapping == &coda_inode->i_data)
+		coda_inode->i_mapping = host_inode->i_mapping;
+
+	/* only allow additional mmaps as long as userspace isn't changing
+	 * the container file on us! */
+	else if (coda_inode->i_mapping != host_inode->i_mapping) {
+		spin_unlock(&cii->c_lock);
+		return -EBUSY;
+	}
+
+	/* keep track of how often the coda_inode/host_file has been mmapped */
+	cii->c_mapcount++;
+	cfi->cfi_mapcount++;
+	spin_unlock(&cii->c_lock);
+
+	return host_file->f_op->mmap(host_file, vma);
+}
+
+int coda_open(struct inode *coda_inode, struct file *coda_file)
+{
+	struct file *host_file = NULL;
+	int error;
+	unsigned short flags = coda_file->f_flags & (~O_EXCL);
+	unsigned short coda_flags = coda_flags_to_cflags(flags);
+	struct coda_file_info *cfi;
+
+	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
+	if (!cfi)
+		return -ENOMEM;
+
+	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
+			   &host_file);
+	if (!host_file)
+		error = -EIO;
+
+	if (error) {
+		kfree(cfi);
+		return error;
+	}
+
+	host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
+
+	cfi->cfi_magic = CODA_MAGIC;
+	cfi->cfi_mapcount = 0;
+	cfi->cfi_container = host_file;
+
+	BUG_ON(coda_file->private_data != NULL);
+	coda_file->private_data = cfi;
+	return 0;
+}
+
+int coda_release(struct inode *coda_inode, struct file *coda_file)
+{
+	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
+	unsigned short coda_flags = coda_flags_to_cflags(flags);
+	struct coda_file_info *cfi;
+	struct coda_inode_info *cii;
+	struct inode *host_inode;
+	int err;
+
+	cfi = CODA_FTOC(coda_file);
+	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
+
+	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
+			  coda_flags, coda_file->f_cred->fsuid);
+
+	host_inode = file_inode(cfi->cfi_container);
+	cii = ITOC(coda_inode);
+
+	/* did we mmap this file? */
+	spin_lock(&cii->c_lock);
+	if (coda_inode->i_mapping == &host_inode->i_data) {
+		cii->c_mapcount -= cfi->cfi_mapcount;
+		if (!cii->c_mapcount)
+			coda_inode->i_mapping = &coda_inode->i_data;
+	}
+	spin_unlock(&cii->c_lock);
+
+	fput(cfi->cfi_container);
+	kfree(coda_file->private_data);
+	coda_file->private_data = NULL;
+
+	/* VFS fput ignores the return value from file_operations->release, so
+	 * there is no use returning an error here */
+	return 0;
+}
+
+int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
+{
+	struct file *host_file;
+	struct inode *coda_inode = file_inode(coda_file);
+	struct coda_file_info *cfi;
+	int err;
+
+	if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
+	      S_ISLNK(coda_inode->i_mode)))
+		return -EINVAL;
+
+	err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
+	if (err)
+		return err;
+	mutex_lock(&coda_inode->i_mutex);
+
+	cfi = CODA_FTOC(coda_file);
+	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
+	host_file = cfi->cfi_container;
+
+	err = vfs_fsync(host_file, datasync);
+	if (!err && !datasync)
+		err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
+	mutex_unlock(&coda_inode->i_mutex);
+
+	return err;
+}
+
+const struct file_operations coda_file_operations = {
+	.llseek		= generic_file_llseek,
+	.read_iter	= coda_file_read_iter,
+	.write_iter	= coda_file_write_iter,
+	.mmap		= coda_file_mmap,
+	.open		= coda_open,
+	.release	= coda_release,
+	.fsync		= coda_fsync,
+	.splice_read	= coda_file_splice_read,
+};
+