litmus-rt.git - The LITMUS^RT kernel.

/*
 *  linux/fs/9p/vfs_inode.c
 *
 * This file contains vfs inode ops for the 9P2000 protocol.
 *
 *  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/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/pagemap.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/namei.h>
#include <linux/idr.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>

#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
#include "cache.h"

static const struct inode_operations v9fs_dir_inode_operations;
static const struct inode_operations v9fs_dir_inode_operations_dotu;
static const struct inode_operations v9fs_dir_inode_operations_dotl;
static const struct inode_operations v9fs_file_inode_operations;
static const struct inode_operations v9fs_file_inode_operations_dotl;
static const struct inode_operations v9fs_symlink_inode_operations;
static const struct inode_operations v9fs_symlink_inode_operations_dotl;

/**
 * unixmode2p9mode - convert unix mode bits to plan 9
 * @v9ses: v9fs session information
 * @mode: mode to convert
 *
 */

static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
{
	int res;
	res = mode & 0777;
	if (S_ISDIR(mode))
		res |= P9_DMDIR;
	if (v9fs_proto_dotu(v9ses)) {
		if (S_ISLNK(mode))
			res |= P9_DMSYMLINK;
		if (v9ses->nodev == 0) {
			if (S_ISSOCK(mode))
				res |= P9_DMSOCKET;
			if (S_ISFIFO(mode))
				res |= P9_DMNAMEDPIPE;
			if (S_ISBLK(mode))
				res |= P9_DMDEVICE;
			if (S_ISCHR(mode))
				res |= P9_DMDEVICE;
		}

		if ((mode & S_ISUID) == S_ISUID)
			res |= P9_DMSETUID;
		if ((mode & S_ISGID) == S_ISGID)
			res |= P9_DMSETGID;
		if ((mode & S_ISVTX) == S_ISVTX)
			res |= P9_DMSETVTX;
		if ((mode & P9_DMLINK))
			res |= P9_DMLINK;
	}

	return res;
}

/**
 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
 * @v9ses: v9fs session information
 * @mode: mode to convert
 *
 */

static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
{
	int res;

	res = mode & 0777;

	if ((mode & P9_DMDIR) == P9_DMDIR)
		res |= S_IFDIR;
	else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
		res |= S_IFLNK;
	else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
		 && (v9ses->nodev == 0))
		res |= S_IFSOCK;
	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
		 && (v9ses->nodev == 0))
		res |= S_IFIFO;
	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
		 && (v9ses->nodev == 0))
		res |= S_IFBLK;
	else
		res |= S_IFREG;

	if (v9fs_proto_dotu(v9ses)) {
		if ((mode & P9_DMSETUID) == P9_DMSETUID)
			res |= S_ISUID;

		if ((mode & P9_DMSETGID) == P9_DMSETGID)
			res |= S_ISGID;

		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
			res |= S_ISVTX;
	}

	return res;
}

/**
 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 * @uflags: flags to convert
 * @extended: if .u extensions are active
 */

int v9fs_uflags2omode(int uflags, int extended)
{
	int ret;

	ret = 0;
	switch (uflags&3) {
	default:
	case O_RDONLY:
		ret = P9_OREAD;
		break;

	case O_WRONLY:
		ret = P9_OWRITE;
		break;

	case O_RDWR:
		ret = P9_ORDWR;
		break;
	}

	if (uflags & O_TRUNC)
		ret |= P9_OTRUNC;

	if (extended) {
		if (uflags & O_EXCL)
			ret |= P9_OEXCL;

		if (uflags & O_APPEND)
			ret |= P9_OAPPEND;
	}

	return ret;
}

/**
 * v9fs_blank_wstat - helper function to setup a 9P stat structure
 * @wstat: structure to initialize
 *
 */

void
v9fs_blank_wstat(struct p9_wstat *wstat)
{
	wstat->type = ~0;
	wstat->dev = ~0;
	wstat->qid.type = ~0;
	wstat->qid.version = ~0;
	*((long long *)&wstat->qid.path) = ~0;
	wstat->mode = ~0;
	wstat->atime = ~0;
	wstat->mtime = ~0;
	wstat->length = ~0;
	wstat->name = NULL;
	wstat->uid = NULL;
	wstat->gid = NULL;
	wstat->muid = NULL;
	wstat->n_uid = ~0;
	wstat->n_gid = ~0;
	wstat->n_muid = ~0;
	wstat->extension = NULL;
}

#ifdef CONFIG_9P_FSCACHE
/**
 * v9fs_alloc_inode - helper function to allocate an inode
 * This callback is executed before setting up the inode so that we
 * can associate a vcookie with each inode.
 *
 */

struct inode *v9fs_alloc_inode(struct super_block *sb)
{
	struct v9fs_cookie *vcookie;
	vcookie = (struct v9fs_cookie *)kmem_cache_alloc(vcookie_cache,
							 GFP_KERNEL);
	if (!vcookie)
		return NULL;

	vcookie->fscache = NULL;
	vcookie->qid = NULL;
	spin_lock_init(&vcookie->lock);
	return &vcookie->inode;
}

/**
 * v9fs_destroy_inode - destroy an inode
 *
 */

void v9fs_destroy_inode(struct inode *inode)
{
	kmem_cache_free(vcookie_cache, v9fs_inode2cookie(inode));
}
#endif

/**
 * v9fs_get_inode - helper function to setup an inode
 * @sb: superblock
 * @mode: mode to setup inode with
 *
 */

struct inode *v9fs_get_inode(struct super_block *sb, int mode)
{
	int err;
	struct inode *inode;
	struct v9fs_session_info *v9ses = sb->s_fs_info;

	P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);

	inode = new_inode(sb);
	if (!inode) {
		P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
		return ERR_PTR(-ENOMEM);
	}

	inode_init_owner(inode, NULL, mode);
	inode->i_blocks = 0;
	inode->i_rdev = 0;
	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	inode->i_mapping->a_ops = &v9fs_addr_operations;

	switch (mode & S_IFMT) {
	case S_IFIFO:
	case S_IFBLK:
	case S_IFCHR:
	case S_IFSOCK:
		if (!v9fs_proto_dotu(v9ses)) {
			P9_DPRINTK(P9_DEBUG_ERROR,
				   "special files without extended mode\n");
			err = -EINVAL;
			goto error;
		}
		init_special_inode(inode, inode->i_mode, inode->i_rdev);
		break;
	case S_IFREG:
		if (v9fs_proto_dotl(v9ses)) {
			inode->i_op = &v9fs_file_inode_operations_dotl;
			inode->i_fop = &v9fs_file_operations_dotl;
		} else {
			inode->i_op = &v9fs_file_inode_operations;
			inode->i_fop = &v9fs_file_operations;
		}

		break;

	case S_IFLNK:
		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
			P9_DPRINTK(P9_DEBUG_ERROR, "extended modes used with "
						"legacy protocol.\n");
			err = -EINVAL;
			goto error;
		}

		if (v9fs_proto_dotl(v9ses))
			inode->i_op = &v9fs_symlink_inode_operations_dotl;
		else
			inode->i_op = &v9fs_symlink_inode_operations;

		break;
	case S_IFDIR:
		inc_nlink(inode);
		if (v9fs_proto_dotl(v9ses))
			inode->i_op = &v9fs_dir_inode_operations_dotl;
		else if (v9fs_proto_dotu(v9ses))
			inode->i_op = &v9fs_dir_inode_operations_dotu;
		else
			inode->i_op = &v9fs_dir_inode_operations;

		if (v9fs_proto_dotl(v9ses))
			inode->i_fop = &v9fs_dir_operations_dotl;
		else
			inode->i_fop = &v9fs_dir_operations;

		break;
	default:
		P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
			   mode, mode & S_IFMT);
		err = -EINVAL;
		goto error;
	}

	return inode;

error:
	iput(inode);
	return ERR_PTR(err);
}

/*
static struct v9fs_fid*
v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
{
	int err;
	int nfid;
	struct v9fs_fid *ret;
	struct v9fs_fcall *fcall;

	nfid = v9fs_get_idpool(&v9ses->fidpool);
	if (nfid < 0) {
		eprintk(KERN_WARNING, "no free fids available\n");
		return ERR_PTR(-ENOSPC);
	}

	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
		&fcall);

	if (err < 0) {
		if (fcall && fcall->id == RWALK)
			goto clunk_fid;

		PRINT_FCALL_ERROR("walk error", fcall);
		v9fs_put_idpool(nfid, &v9ses->fidpool);
		goto error;
	}

	kfree(fcall);
	fcall = NULL;
	ret = v9fs_fid_create(v9ses, nfid);
	if (!ret) {
		err = -ENOMEM;
		goto clunk_fid;
	}

	err = v9fs_fid_insert(ret, dentry);
	if (err < 0) {
		v9fs_fid_destroy(ret);
		goto clunk_fid;
	}

	return ret;

clunk_fid:
	v9fs_t_clunk(v9ses, nfid);

error:
	kfree(fcall);
	return ERR_PTR(err);
}
*/


/**
 * v9fs_clear_inode - release an inode
 * @inode: inode to release
 *
 */
void v9fs_clear_inode(struct inode *inode)
{
	filemap_fdatawrite(inode->i_mapping);

#ifdef CONFIG_9P_FSCACHE
	v9fs_cache_inode_put_cookie(inode);
#endif
}

/**
 * v9fs_inode_from_fid - populate an inode by issuing a attribute request
 * @v9ses: session information
 * @fid: fid to issue attribute request for
 * @sb: superblock on which to create inode
 *
 */

static struct inode *
v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
	struct super_block *sb)
{
	int err, umode;
	struct inode *ret;
	struct p9_wstat *st;

	ret = NULL;
	st = p9_client_stat(fid);
	if (IS_ERR(st))
		return ERR_CAST(st);

	umode = p9mode2unixmode(v9ses, st->mode);
	ret = v9fs_get_inode(sb, umode);
	if (IS_ERR(ret)) {
		err = PTR_ERR(ret);
		goto error;
	}

	v9fs_stat2inode(st, ret, sb);
	ret->i_ino = v9fs_qid2ino(&st->qid);

#ifdef CONFIG_9P_FSCACHE
	v9fs_vcookie_set_qid(ret, &st->qid);
	v9fs_cache_inode_get_cookie(ret);
#endif
	p9stat_free(st);
	kfree(st);

	return ret;

error:
	p9stat_free(st);
	kfree(st);
	return ERR_PTR(err);
}

/**
 * v9fs_remove - helper function to remove files and directories
 * @dir: directory inode that is being deleted
 * @file:  dentry that is being deleted
 * @rmdir: removing a directory
 *
 */

static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
{
	int retval;
Mode	Name	Size
-rw-r--r--	.gitignore	936	log stats plain blame
-rw-r--r--	.mailmap	4021	log stats plain blame
-rw-r--r--	COPYING	18693	log stats plain blame
-rw-r--r--	CREDITS	94019	log stats plain blame
d---------	Documentation	8331	log stats plain
-rw-r--r--	Kbuild	2440	log stats plain blame
-rw-r--r--	MAINTAINERS	179293	log stats plain blame
-rw-r--r--	Makefile	51752	log stats plain blame
-rw-r--r--	README	17459	log stats plain blame
-rw-r--r--	REPORTING-BUGS	3371	log stats plain blame
d---------	arch	840	log stats plain
d---------	block	1162	log stats plain
d---------	crypto	2955	log stats plain
d---------	drivers	2861	log stats plain
d---------	firmware	1906	log stats plain
d---------	fs	4922	log stats plain
d---------	include	609	log stats plain
d---------	init	469	log stats plain
d---------	ipc	550	log stats plain
d---------	kernel	5310	log stats plain
d---------	lib	5056	log stats plain
d---------	mm	2811	log stats plain
d---------	net	1833	log stats plain
d---------	samples	288	log stats plain
d---------	scripts	2939	log stats plain
d---------	security	544	log stats plain
d---------	sound	814	log stats plain
d---------	tools	96	log stats plain
d---------	usr	388	log stats plain
d---------	virt / kvm	30	log stats plain