--- /dev/null
+/*
+ * 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,
+};
+
Code Review / kvmfornfv.git / blobdiff