mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-22 08:49:45 +00:00
![Al Viro](/assets/img/avatar_default.png)
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
230 lines
6 KiB
C
230 lines
6 KiB
C
/*
|
|
* 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);
|
|
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_SEC;
|
|
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 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;
|
|
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 = coda_file_splice_read,
|
|
};
|
|
|