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/*
* 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_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);
inode_lock(coda_inode);
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(coda_inode);
inode_unlock(coda_inode);
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 call_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;
inode_lock(coda_inode);
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));
inode_unlock(coda_inode);
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 = generic_file_splice_read,
};
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