linux/fs/coda/file.c
Miklos Szeredi 75e1fcc0b1 [PATCH] vfs: add lock owner argument to flush operation
Pass the POSIX lock owner ID to the flush operation.

This is useful for filesystems which don't want to store any locking state
in inode->i_flock but want to handle locking/unlocking POSIX locks
internally.  FUSE is one such filesystem but I think it possible that some
network filesystems would need this also.

Also add a flag to indicate that a POSIX locking request was generated by
close(), so filesystems using the above feature won't send an extra locking
request in this case.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:43:02 -07:00

303 lines
7.4 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/errno.h>
#include <linux/smp_lock.h>
#include <linux/string.h>
#include <asm/uaccess.h>
#include <linux/coda.h>
#include <linux/coda_linux.h>
#include <linux/coda_fs_i.h>
#include <linux/coda_psdev.h>
#include <linux/coda_proc.h>
#include "coda_int.h"
/* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support
* CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */
static int use_coda_close;
static ssize_t
coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos)
{
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;
if (!host_file->f_op || !host_file->f_op->read)
return -EINVAL;
return host_file->f_op->read(host_file, buf, count, ppos);
}
static ssize_t
coda_file_sendfile(struct file *coda_file, loff_t *ppos, size_t count,
read_actor_t actor, void *target)
{
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;
if (!host_file->f_op || !host_file->f_op->sendfile)
return -EINVAL;
return host_file->f_op->sendfile(host_file, ppos, count, actor, target);
}
static ssize_t
coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
{
struct inode *host_inode, *coda_inode = coda_file->f_dentry->d_inode;
struct coda_file_info *cfi;
struct file *host_file;
ssize_t ret;
cfi = CODA_FTOC(coda_file);
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
host_file = cfi->cfi_container;
if (!host_file->f_op || !host_file->f_op->write)
return -EINVAL;
host_inode = host_file->f_dentry->d_inode;
mutex_lock(&coda_inode->i_mutex);
ret = host_file->f_op->write(host_file, buf, count, ppos);
coda_inode->i_size = host_inode->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);
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 || !host_file->f_op->mmap)
return -ENODEV;
coda_inode = coda_file->f_dentry->d_inode;
host_inode = host_file->f_dentry->d_inode;
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)
return -EBUSY;
/* keep track of how often the coda_inode/host_file has been mmapped */
cii = ITOC(coda_inode);
cii->c_mapcount++;
cfi->cfi_mapcount++;
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;
coda_vfs_stat.open++;
cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
if (!cfi) {
unlock_kernel();
return -ENOMEM;
}
lock_kernel();
error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
&host_file);
if (error || !host_file) {
kfree(cfi);
unlock_kernel();
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;
unlock_kernel();
return 0;
}
int coda_flush(struct file *coda_file, fl_owner_t id)
{
unsigned short flags = coda_file->f_flags & ~O_EXCL;
unsigned short coda_flags = coda_flags_to_cflags(flags);
struct coda_file_info *cfi;
struct inode *coda_inode;
int err = 0, fcnt;
lock_kernel();
coda_vfs_stat.flush++;
/* last close semantics */
fcnt = file_count(coda_file);
if (fcnt > 1)
goto out;
/* No need to make an upcall when we have not made any modifications
* to the file */
if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY)
goto out;
if (use_coda_close)
goto out;
cfi = CODA_FTOC(coda_file);
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
coda_inode = coda_file->f_dentry->d_inode;
err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
coda_file->f_uid);
if (err == -EOPNOTSUPP) {
use_coda_close = 1;
err = 0;
}
out:
unlock_kernel();
return err;
}
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 = 0;
lock_kernel();
coda_vfs_stat.release++;
if (!use_coda_close) {
err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode),
coda_flags);
if (err == -EOPNOTSUPP) {
use_coda_close = 1;
err = 0;
}
}
cfi = CODA_FTOC(coda_file);
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
if (use_coda_close)
err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
coda_flags, coda_file->f_uid);
host_inode = cfi->cfi_container->f_dentry->d_inode;
cii = ITOC(coda_inode);
/* did we mmap this file? */
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;
}
fput(cfi->cfi_container);
kfree(coda_file->private_data);
coda_file->private_data = NULL;
unlock_kernel();
return err;
}
int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync)
{
struct file *host_file;
struct dentry *host_dentry;
struct inode *host_inode, *coda_inode = coda_dentry->d_inode;
struct coda_file_info *cfi;
int err = 0;
if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
S_ISLNK(coda_inode->i_mode)))
return -EINVAL;
cfi = CODA_FTOC(coda_file);
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
host_file = cfi->cfi_container;
coda_vfs_stat.fsync++;
if (host_file->f_op && host_file->f_op->fsync) {
host_dentry = host_file->f_dentry;
host_inode = host_dentry->d_inode;
mutex_lock(&host_inode->i_mutex);
err = host_file->f_op->fsync(host_file, host_dentry, datasync);
mutex_unlock(&host_inode->i_mutex);
}
if ( !err && !datasync ) {
lock_kernel();
err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
unlock_kernel();
}
return err;
}
const struct file_operations coda_file_operations = {
.llseek = generic_file_llseek,
.read = coda_file_read,
.write = coda_file_write,
.mmap = coda_file_mmap,
.open = coda_open,
.flush = coda_flush,
.release = coda_release,
.fsync = coda_fsync,
.sendfile = coda_file_sendfile,
};