android_kernel_xiaomi_sm8350/fs/9p/vfs_super.c
Eric Van Hensbergen a80d923e13 9p: Make transports dynamic
This patch abstracts out the interfaces to underlying transports so that
new transports can be added as modules.  This should also allow kernel
configuration of transports without ifdef-hell.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2007-10-17 14:31:07 -05:00

245 lines
5.2 KiB
C

/*
* linux/fs/9p/vfs_super.c
*
* This file contians superblock ops for 9P2000. It is intended that
* you mount this file system on directories.
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to:
* Free Software Foundation
* 51 Franklin Street, Fifth Floor
* Boston, MA 02111-1301 USA
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/pagemap.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/idr.h>
#include <linux/sched.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
static void v9fs_clear_inode(struct inode *);
static const struct super_operations v9fs_super_ops;
/**
* v9fs_clear_inode - release an inode
* @inode: inode to release
*
*/
static void v9fs_clear_inode(struct inode *inode)
{
filemap_fdatawrite(inode->i_mapping);
}
/**
* v9fs_set_super - set the superblock
* @s: super block
* @data: file system specific data
*
*/
static int v9fs_set_super(struct super_block *s, void *data)
{
s->s_fs_info = data;
return set_anon_super(s, data);
}
/**
* v9fs_fill_super - populate superblock with info
* @sb: superblock
* @v9ses: session information
*
*/
static void
v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
int flags)
{
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
sb->s_blocksize = 1 << sb->s_blocksize_bits;
sb->s_magic = V9FS_MAGIC;
sb->s_op = &v9fs_super_ops;
sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
MS_NOATIME;
}
/**
* v9fs_get_sb - mount a superblock
* @fs_type: file system type
* @flags: mount flags
* @dev_name: device name that was mounted
* @data: mount options
* @mnt: mountpoint record to be instantiated
*
*/
static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data,
struct vfsmount *mnt)
{
struct super_block *sb = NULL;
struct inode *inode = NULL;
struct dentry *root = NULL;
struct v9fs_session_info *v9ses = NULL;
struct p9_stat *st = NULL;
int mode = S_IRWXUGO | S_ISVTX;
uid_t uid = current->fsuid;
gid_t gid = current->fsgid;
struct p9_fid *fid;
int retval = 0;
P9_DPRINTK(P9_DEBUG_VFS, " \n");
v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
if (!v9ses)
return -ENOMEM;
fid = v9fs_session_init(v9ses, dev_name, data);
if (IS_ERR(fid)) {
retval = PTR_ERR(fid);
fid = NULL;
kfree(v9ses);
v9ses = NULL;
goto error;
}
st = p9_client_stat(fid);
if (IS_ERR(st)) {
retval = PTR_ERR(st);
goto error;
}
sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
if (IS_ERR(sb)) {
retval = PTR_ERR(sb);
goto error;
}
v9fs_fill_super(sb, v9ses, flags);
inode = v9fs_get_inode(sb, S_IFDIR | mode);
if (IS_ERR(inode)) {
retval = PTR_ERR(inode);
goto error;
}
inode->i_uid = uid;
inode->i_gid = gid;
root = d_alloc_root(inode);
if (!root) {
retval = -ENOMEM;
goto error;
}
sb->s_root = root;
root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
v9fs_stat2inode(st, root->d_inode, sb);
v9fs_fid_add(root, fid);
return simple_set_mnt(mnt, sb);
error:
if (fid)
p9_client_clunk(fid);
if (v9ses) {
v9fs_session_close(v9ses);
kfree(v9ses);
}
if (sb) {
up_write(&sb->s_umount);
deactivate_super(sb);
}
return retval;
}
/**
* v9fs_kill_super - Kill Superblock
* @s: superblock
*
*/
static void v9fs_kill_super(struct super_block *s)
{
struct v9fs_session_info *v9ses = s->s_fs_info;
P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
v9fs_dentry_release(s->s_root); /* clunk root */
kill_anon_super(s);
v9fs_session_close(v9ses);
kfree(v9ses);
P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
}
/**
* v9fs_show_options - Show mount options in /proc/mounts
* @m: seq_file to write to
* @mnt: mount descriptor
*
*/
static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
{
struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
seq_printf(m, "%s", v9ses->options);
return 0;
}
static void
v9fs_umount_begin(struct vfsmount *vfsmnt, int flags)
{
struct v9fs_session_info *v9ses = vfsmnt->mnt_sb->s_fs_info;
if (flags & MNT_FORCE)
v9fs_session_cancel(v9ses);
}
static const struct super_operations v9fs_super_ops = {
.statfs = simple_statfs,
.clear_inode = v9fs_clear_inode,
.show_options = v9fs_show_options,
.umount_begin = v9fs_umount_begin,
};
struct file_system_type v9fs_fs_type = {
.name = "9p",
.get_sb = v9fs_get_sb,
.kill_sb = v9fs_kill_super,
.owner = THIS_MODULE,
};