vfs_inode.c 33.3 KB
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/*
 *  linux/fs/9p/vfs_inode.c
 *
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 * This file contains vfs inode ops for the 9P2000 protocol.
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 *
 *  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
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 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
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 *
 *  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
 *
 */

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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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#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>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/xattr.h>
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#include <linux/posix_acl.h>
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#include <net/9p/9p.h>
#include <net/9p/client.h>
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#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
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#include "cache.h"
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#include "xattr.h"
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#include "acl.h"
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static const struct inode_operations v9fs_dir_inode_operations;
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static const struct inode_operations v9fs_dir_inode_operations_dotu;
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static const struct inode_operations v9fs_file_inode_operations;
static const struct inode_operations v9fs_symlink_inode_operations;
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/**
 * unixmode2p9mode - convert unix mode bits to plan 9
 * @v9ses: v9fs session information
 * @mode: mode to convert
 *
 */

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static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
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{
	int res;
	res = mode & 0777;
	if (S_ISDIR(mode))
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		res |= P9_DMDIR;
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	if (v9fs_proto_dotu(v9ses)) {
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		if (v9ses->nodev == 0) {
			if (S_ISSOCK(mode))
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				res |= P9_DMSOCKET;
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			if (S_ISFIFO(mode))
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				res |= P9_DMNAMEDPIPE;
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			if (S_ISBLK(mode))
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				res |= P9_DMDEVICE;
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			if (S_ISCHR(mode))
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				res |= P9_DMDEVICE;
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		}

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

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/**
 * p9mode2perm- convert plan9 mode bits to unix permission bits
 * @v9ses: v9fs session information
 * @stat: p9_wstat from which mode need to be derived
 *
 */
static int p9mode2perm(struct v9fs_session_info *v9ses,
		       struct p9_wstat *stat)
{
	int res;
	int mode = stat->mode;

	res = mode & S_IALLUGO;
	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;
}

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/**
 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
 * @v9ses: v9fs session information
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 * @stat: p9_wstat from which mode need to be derived
 * @rdev: major number, minor number in case of device files.
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 *
 */
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static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
			       struct p9_wstat *stat, dev_t *rdev)
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{
	int res;
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	u32 mode = stat->mode;
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	*rdev = 0;
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	res = p9mode2perm(v9ses, stat);
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	if ((mode & P9_DMDIR) == P9_DMDIR)
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		res |= S_IFDIR;
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	else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
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		res |= S_IFLNK;
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	else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
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		 && (v9ses->nodev == 0))
		res |= S_IFSOCK;
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	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
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		 && (v9ses->nodev == 0))
		res |= S_IFIFO;
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	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
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		 && (v9ses->nodev == 0)) {
		char type = 0, ext[32];
		int major = -1, minor = -1;

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		strlcpy(ext, stat->extension, sizeof(ext));
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		sscanf(ext, "%c %i %i", &type, &major, &minor);
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		switch (type) {
		case 'c':
			res |= S_IFCHR;
			break;
		case 'b':
			res |= S_IFBLK;
			break;
		default:
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			p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
				 type, stat->extension);
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		};
		*rdev = MKDEV(major, minor);
	} else
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		res |= S_IFREG;

	return res;
}

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

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

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

	case O_WRONLY:
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		ret = P9_OWRITE;
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		break;

	case O_RDWR:
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		ret = P9_ORDWR;
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		break;
	}

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

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

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

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void
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v9fs_blank_wstat(struct p9_wstat *wstat)
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{
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	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;
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	wstat->n_uid = INVALID_UID;
	wstat->n_gid = INVALID_GID;
	wstat->n_muid = INVALID_UID;
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	wstat->extension = NULL;
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}

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/**
 * v9fs_alloc_inode - helper function to allocate an inode
 *
 */
struct inode *v9fs_alloc_inode(struct super_block *sb)
{
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	struct v9fs_inode *v9inode;
	v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
							GFP_KERNEL);
	if (!v9inode)
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		return NULL;
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#ifdef CONFIG_9P_FSCACHE
	v9inode->fscache = NULL;
	spin_lock_init(&v9inode->fscache_lock);
#endif
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	v9inode->writeback_fid = NULL;
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	v9inode->cache_validity = 0;
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	mutex_init(&v9inode->v_mutex);
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	return &v9inode->vfs_inode;
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}

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

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static void v9fs_i_callback(struct rcu_head *head)
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{
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	struct inode *inode = container_of(head, struct inode, i_rcu);
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	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
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}
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void v9fs_destroy_inode(struct inode *inode)
{
	call_rcu(&inode->i_rcu, v9fs_i_callback);
}
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int v9fs_init_inode(struct v9fs_session_info *v9ses,
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		    struct inode *inode, umode_t mode, dev_t rdev)
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{
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	int err = 0;
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	inode_init_owner(inode, NULL, mode);
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	inode->i_blocks = 0;
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	inode->i_rdev = rdev;
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	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:
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		if (v9fs_proto_dotl(v9ses)) {
			inode->i_op = &v9fs_file_inode_operations_dotl;
		} else if (v9fs_proto_dotu(v9ses)) {
			inode->i_op = &v9fs_file_inode_operations;
		} else {
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			p9_debug(P9_DEBUG_ERROR,
				 "special files without extended mode\n");
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			err = -EINVAL;
			goto error;
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		}
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		init_special_inode(inode, inode->i_mode, inode->i_rdev);
		break;
	case S_IFREG:
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		if (v9fs_proto_dotl(v9ses)) {
			inode->i_op = &v9fs_file_inode_operations_dotl;
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			if (v9ses->cache == CACHE_LOOSE ||
			    v9ses->cache == CACHE_FSCACHE)
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				inode->i_fop =
					&v9fs_cached_file_operations_dotl;
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			else if (v9ses->cache == CACHE_MMAP)
				inode->i_fop = &v9fs_mmap_file_operations_dotl;
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			else
				inode->i_fop = &v9fs_file_operations_dotl;
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		} else {
			inode->i_op = &v9fs_file_inode_operations;
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			if (v9ses->cache == CACHE_LOOSE ||
			    v9ses->cache == CACHE_FSCACHE)
				inode->i_fop =
					&v9fs_cached_file_operations;
			else if (v9ses->cache == CACHE_MMAP)
				inode->i_fop = &v9fs_mmap_file_operations;
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			else
				inode->i_fop = &v9fs_file_operations;
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		}

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		break;
	case S_IFLNK:
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		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
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			p9_debug(P9_DEBUG_ERROR,
				 "extended modes used with legacy protocol\n");
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			err = -EINVAL;
			goto error;
		}
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		if (v9fs_proto_dotl(v9ses))
			inode->i_op = &v9fs_symlink_inode_operations_dotl;
		else
			inode->i_op = &v9fs_symlink_inode_operations;

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		break;
	case S_IFDIR:
		inc_nlink(inode);
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		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;
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		else
			inode->i_op = &v9fs_dir_inode_operations;
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		if (v9fs_proto_dotl(v9ses))
			inode->i_fop = &v9fs_dir_operations_dotl;
		else
			inode->i_fop = &v9fs_dir_operations;

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		break;
	default:
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		p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
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			 mode, mode & S_IFMT);
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		err = -EINVAL;
		goto error;
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	}
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error:
	return err;
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}
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/**
 * v9fs_get_inode - helper function to setup an inode
 * @sb: superblock
 * @mode: mode to setup inode with
 *
 */

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

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	p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
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	inode = new_inode(sb);
	if (!inode) {
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		pr_warn("%s (%d): Problem allocating inode\n",
			__func__, task_pid_nr(current));
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		return ERR_PTR(-ENOMEM);
	}
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	err = v9fs_init_inode(v9ses, inode, mode, rdev);
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	if (err) {
		iput(inode);
		return ERR_PTR(err);
	}
	return inode;
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}

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

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

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

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

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		PRINT_FCALL_ERROR("walk error", fcall);
		v9fs_put_idpool(nfid, &v9ses->fidpool);
		goto error;
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	}
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	kfree(fcall);
	fcall = NULL;
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	ret = v9fs_fid_create(v9ses, nfid);
	if (!ret) {
		err = -ENOMEM;
		goto clunk_fid;
	}
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	err = v9fs_fid_insert(ret, dentry);
	if (err < 0) {
		v9fs_fid_destroy(ret);
		goto clunk_fid;
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	}
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	return ret;
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clunk_fid:
	v9fs_t_clunk(v9ses, nfid);
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error:
	kfree(fcall);
	return ERR_PTR(err);
}
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*/
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/**
 * v9fs_clear_inode - release an inode
 * @inode: inode to release
 *
 */
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void v9fs_evict_inode(struct inode *inode)
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{
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	struct v9fs_inode *v9inode = V9FS_I(inode);

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	truncate_inode_pages_final(inode->i_mapping);
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	clear_inode(inode);
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	filemap_fdatawrite(inode->i_mapping);

	v9fs_cache_inode_put_cookie(inode);
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	/* clunk the fid stashed in writeback_fid */
	if (v9inode->writeback_fid) {
		p9_client_clunk(v9inode->writeback_fid);
		v9inode->writeback_fid = NULL;
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	}
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}

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static int v9fs_test_inode(struct inode *inode, void *data)
{
	int umode;
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	dev_t rdev;
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	struct v9fs_inode *v9inode = V9FS_I(inode);
	struct p9_wstat *st = (struct p9_wstat *)data;
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);

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	umode = p9mode2unixmode(v9ses, st, &rdev);
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	/* don't match inode of different type */
	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
		return 0;

	/* compare qid details */
	if (memcmp(&v9inode->qid.version,
		   &st->qid.version, sizeof(v9inode->qid.version)))
		return 0;

	if (v9inode->qid.type != st->qid.type)
		return 0;
	return 1;
}

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static int v9fs_test_new_inode(struct inode *inode, void *data)
{
	return 0;
}

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static int v9fs_set_inode(struct inode *inode,  void *data)
{
	struct v9fs_inode *v9inode = V9FS_I(inode);
	struct p9_wstat *st = (struct p9_wstat *)data;

	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
	return 0;
}

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static struct inode *v9fs_qid_iget(struct super_block *sb,
				   struct p9_qid *qid,
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				   struct p9_wstat *st,
				   int new)
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{
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	dev_t rdev;
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	int retval;
	umode_t umode;
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	unsigned long i_ino;
	struct inode *inode;
	struct v9fs_session_info *v9ses = sb->s_fs_info;
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	int (*test)(struct inode *, void *);

	if (new)
		test = v9fs_test_new_inode;
	else
		test = v9fs_test_inode;
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	i_ino = v9fs_qid2ino(qid);
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	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
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	if (!inode)
		return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
		return inode;
	/*
	 * initialize the inode with the stat info
	 * FIXME!! we may need support for stale inodes
	 * later.
	 */
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	inode->i_ino = i_ino;
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	umode = p9mode2unixmode(v9ses, st, &rdev);
	retval = v9fs_init_inode(v9ses, inode, umode, rdev);
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	if (retval)
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		goto error;
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	v9fs_stat2inode(st, inode, sb);
	v9fs_cache_inode_get_cookie(inode);
	unlock_new_inode(inode);
	return inode;
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error:
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	unlock_new_inode(inode);
	iput(inode);
	return ERR_PTR(retval);

}

struct inode *
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v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
551
		    struct super_block *sb, int new)
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{
	struct p9_wstat *st;
	struct inode *inode = NULL;

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

560
	inode = v9fs_qid_iget(sb, &st->qid, st, new);
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	p9stat_free(st);
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	kfree(st);
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	return inode;
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}

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/**
 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 * plan 9 AT flag.
 * @flags: flags to convert
 */
static int v9fs_at_to_dotl_flags(int flags)
{
	int rflags = 0;
	if (flags & AT_REMOVEDIR)
		rflags |= P9_DOTL_AT_REMOVEDIR;
	return rflags;
}

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/**
 * v9fs_remove - helper function to remove files and directories
581
 * @dir: directory inode that is being deleted
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 * @dentry:  dentry that is being deleted
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583
 * @flags: removing a directory
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 *
 */

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static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
588
{
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	struct inode *inode;
	int retval = -EOPNOTSUPP;
	struct p9_fid *v9fid, *dfid;
	struct v9fs_session_info *v9ses;
593

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	p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
		 dir, dentry, flags);
596

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	v9ses = v9fs_inode2v9ses(dir);
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	inode = d_inode(dentry);
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	dfid = v9fs_fid_lookup(dentry->d_parent);
	if (IS_ERR(dfid)) {
		retval = PTR_ERR(dfid);
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		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
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		return retval;
	}
	if (v9fs_proto_dotl(v9ses))
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		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
					    v9fs_at_to_dotl_flags(flags));
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	if (retval == -EOPNOTSUPP) {
		/* Try the one based on path */
		v9fid = v9fs_fid_clone(dentry);
		if (IS_ERR(v9fid))
			return PTR_ERR(v9fid);
		retval = p9_client_remove(v9fid);
	}
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	if (!retval) {
		/*
		 * directories on unlink should have zero
		 * link count
		 */
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		if (flags & AT_REMOVEDIR) {
			clear_nlink(inode);
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			drop_nlink(dir);
		} else
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			drop_nlink(inode);
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		v9fs_invalidate_inode_attr(inode);
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		v9fs_invalidate_inode_attr(dir);
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	}
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	return retval;
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}

/**
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 * v9fs_create - Create a file
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 * @v9ses: session information
 * @dir: directory that dentry is being created in
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 * @dentry:  dentry that is being created
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 * @extension: 9p2000.u extension string to support devices, etc.
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 * @perm: create permissions
 * @mode: open mode
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 *
 */
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static struct p9_fid *
v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
		struct dentry *dentry, char *extension, u32 perm, u8 mode)
645
{
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	int err;
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	char *name;
	struct p9_fid *dfid, *ofid, *fid;
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	struct inode *inode;

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	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
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	err = 0;
	ofid = NULL;
	fid = NULL;
	name = (char *) dentry->d_name.name;
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	dfid = v9fs_fid_lookup(dentry->d_parent);
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	if (IS_ERR(dfid)) {
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		err = PTR_ERR(dfid);
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		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
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		return ERR_PTR(err);
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	}
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	/* clone a fid to use for creation */
	ofid = p9_client_walk(dfid, 0, NULL, 1);
	if (IS_ERR(ofid)) {
		err = PTR_ERR(ofid);
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		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
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		return ERR_PTR(err);
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	}
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	err = p9_client_fcreate(ofid, name, perm, mode, extension);
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	if (err < 0) {
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		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
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		goto error;
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	}
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	if (!(perm & P9_DMLINK)) {
		/* now walk from the parent so we can get unopened fid */
		fid = p9_client_walk(dfid, 1, &name, 1);
		if (IS_ERR(fid)) {
			err = PTR_ERR(fid);
			p9_debug(P9_DEBUG_VFS,
				   "p9_client_walk failed %d\n", err);
			fid = NULL;
			goto error;
		}
		/*
		 * instantiate inode and assign the unopened fid to the dentry
		 */
		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
		if (IS_ERR(inode)) {
			err = PTR_ERR(inode);
			p9_debug(P9_DEBUG_VFS,
				   "inode creation failed %d\n", err);
			goto error;
		}
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		v9fs_fid_add(dentry, fid);
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		d_instantiate(dentry, inode);
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	}
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	return ofid;
error:
	if (ofid)
		p9_client_clunk(ofid);

	if (fid)
		p9_client_clunk(fid);

	return ERR_PTR(err);
}

/**
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 * v9fs_vfs_create - VFS hook to create a regular file
 *
 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 * for mknod(2).
 *
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 * @dir: directory inode that is being created
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 * @dentry:  dentry that is being deleted
 * @mode: create permissions
 *
 */
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static int
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v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
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		bool excl)
727
{
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	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
	u32 perm = unixmode2p9mode(v9ses, mode);
	struct p9_fid *fid;
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	/* P9_OEXCL? */
	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
	if (IS_ERR(fid))
		return PTR_ERR(fid);
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	v9fs_invalidate_inode_attr(dir);
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	p9_client_clunk(fid);
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	return 0;
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}

/**
 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
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 * @dir:  inode that is being unlinked
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 * @dentry: dentry that is being unlinked
 * @mode: mode for new directory
 *
 */

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static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
752
{
753
	int err;
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	u32 perm;
	struct p9_fid *fid;
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	struct v9fs_session_info *v9ses;
757

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	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
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	err = 0;
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	v9ses = v9fs_inode2v9ses(dir);
	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
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	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
	if (IS_ERR(fid)) {
		err = PTR_ERR(fid);
		fid = NULL;
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	} else {
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		inc_nlink(dir);
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		v9fs_invalidate_inode_attr(dir);
	}
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	if (fid)
		p9_client_clunk(fid);
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	return err;
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}

/**
 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 * @dir:  inode that is being walked from
 * @dentry: dentry that is being walked to?
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781
 * @flags: lookup flags (unused)
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 *
 */

785
struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
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786
				      unsigned int flags)
787
{
788
	struct dentry *res;
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	struct v9fs_session_info *v9ses;
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	struct p9_fid *dfid, *fid;
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	struct inode *inode;
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	char *name;
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	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
		 dir, dentry, dentry, flags);
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	if (dentry->d_name.len > NAME_MAX)
		return ERR_PTR(-ENAMETOOLONG);

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	v9ses = v9fs_inode2v9ses(dir);
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	/* We can walk d_parent because we hold the dir->i_mutex */
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	dfid = v9fs_fid_lookup(dentry->d_parent);
	if (IS_ERR(dfid))
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		return ERR_CAST(dfid);
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	name = (char *) dentry->d_name.name;
	fid = p9_client_walk(dfid, 1, &name, 1);
	if (IS_ERR(fid)) {
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		if (fid == ERR_PTR(-ENOENT)) {
			d_add(dentry, NULL);
			return NULL;
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		}
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		return ERR_CAST(fid);
814
	}
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	/*
	 * Make sure we don't use a wrong inode due to parallel
	 * unlink. For cached mode create calls request for new
	 * inode. But with cache disabled, lookup should do this.
	 */
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	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
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		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
	else
		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
824
	if (IS_ERR(inode)) {
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		p9_client_clunk(fid);
		return ERR_CAST(inode);
827
	}
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	/*
	 * If we had a rename on the server and a parallel lookup
	 * for the new name, then make sure we instantiate with
	 * the new name. ie look up for a/b, while on server somebody
	 * moved b under k and client parallely did a lookup for
	 * k/b.
	 */
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	res = d_splice_alias(inode, dentry);
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	if (!res)
		v9fs_fid_add(dentry, fid);
	else if (!IS_ERR(res))
		v9fs_fid_add(res, fid);
	else
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		p9_client_clunk(fid);
	return res;
843
844
}

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static int
846
v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
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		     struct file *file, unsigned flags, umode_t mode,
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		     int *opened)
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{
	int err;
	u32 perm;
	struct v9fs_inode *v9inode;
	struct v9fs_session_info *v9ses;
	struct p9_fid *fid, *inode_fid;
	struct dentry *res = NULL;

	if (d_unhashed(dentry)) {
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858
		res = v9fs_vfs_lookup(dir, dentry, 0);
859
		if (IS_ERR(res))
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			return PTR_ERR(res);
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		if (res)
			dentry = res;
	}

	/* Only creates */
867
	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
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868
		return finish_no_open(file, res);
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870

	err = 0;
Geyslan G. Bem's avatar
Geyslan G. Bem committed
871

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	v9ses = v9fs_inode2v9ses(dir);
	perm = unixmode2p9mode(v9ses, mode);
	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
				v9fs_uflags2omode(flags,
						v9fs_proto_dotu(v9ses)));
	if (IS_ERR(fid)) {
		err = PTR_ERR(fid);
		fid = NULL;
		goto error;
	}

	v9fs_invalidate_inode_attr(dir);
884
	v9inode = V9FS_I(d_inode(dentry));
885
	mutex_lock(&v9inode->v_mutex);
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	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
	    !v9inode->writeback_fid &&
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	    ((flags & O_ACCMODE) != O_RDONLY)) {
		/*
		 * clone a fid and add it to writeback_fid
		 * we do it during open time instead of
		 * page dirty time via write_begin/page_mkwrite
		 * because we want write after unlink usecase
		 * to work.
		 */
		inode_fid = v9fs_writeback_fid(dentry);
		if (IS_ERR(inode_fid)) {
			err = PTR_ERR(inode_fid);
			mutex_unlock(&v9inode->v_mutex);
			goto error;
		}
		v9inode->writeback_fid = (void *) inode_fid;
	}
	mutex_unlock(&v9inode->v_mutex);
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906
	err = finish_open(file, dentry, generic_file_open, opened);
	if (err)
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		goto error;

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909
	file->private_data = fid;
910
	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
911
		v9fs_cache_inode_set_cookie(d_inode(dentry), file);
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913
	*opened |= FILE_CREATED;
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915
out:
	dput(res);
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916
	return err;
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923

error:
	if (fid)
		p9_client_clunk(fid);
	goto out;
}

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/**
 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 * @i:  inode that is being unlinked
927
 * @d: dentry that is being unlinked
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 *
 */

931
int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
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938
{
	return v9fs_remove(i, d, 0);
}

/**
 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 * @i:  inode that is being unlinked
939
 * @d: dentry that is being unlinked
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 *
 */

943
int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
944
{
945
	return v9fs_remove(i, d, AT_REMOVEDIR);
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}

/**
 * v9fs_vfs_rename - VFS hook to rename an inode
 * @old_dir:  old dir inode
 * @old_dentry: old dentry
 * @new_dir: new dir inode
 * @new_dentry: new dentry
 *
 */

957
int
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960
v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
		struct inode *new_dir, struct dentry *new_dentry)
{
961
	int retval;
962
	struct inode *old_inode;
963
	struct inode *new_inode;
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	struct v9fs_session_info *v9ses;
	struct p9_fid *oldfid;
	struct p9_fid *olddirfid;
	struct p9_fid *newdirfid;
	struct p9_wstat wstat;
969

970
	p9_debug(P9_DEBUG_VFS, "\n");
971
	retval = 0;
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973
	old_inode = d_inode(old_dentry);
	new_inode = d_inode(new_dentry);
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975
	v9ses = v9fs_inode2v9ses(old_inode);
	oldfid = v9fs_fid_lookup(old_dentry);
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	if (IS_ERR(oldfid))
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979
		return PTR_ERR(oldfid);

	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
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	if (IS_ERR(olddirfid)) {
981
		retval = PTR_ERR(olddirfid);
982
		goto done;
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	}

	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
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	if (IS_ERR(newdirfid)) {
987
		retval = PTR_ERR(newdirfid);
988
		goto clunk_olddir;
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	}

991
	down_write(&v9ses->rename_sem);
992
	if (v9fs_proto_dotl(v9ses)) {
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		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
					    newdirfid, new_dentry->d_name.name);
		if (retval == -EOPNOTSUPP)
			retval = p9_client_rename(oldfid, newdirfid,
						  new_dentry->d_name.name);
		if (retval != -EOPNOTSUPP)
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			goto clunk_newdir;
	}
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1004
	if (old_dentry->d_parent != new_dentry->d_parent) {
		/*
		 * 9P .u can only handle file rename in the same directory
		 */
1005

1006
		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
1007
		retval = -EXDEV;
1008
		goto clunk_newdir;
1009
	}
1010
	v9fs_blank_wstat(&wstat);
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1011
	wstat.muid = v9ses->uname;
1012
	wstat.name = (char *) new_dentry->d_name.name;
1013
	retval = p9_client_wstat(oldfid, &wstat);
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1015
clunk_newdir:
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	if (!retval) {
		if (new_inode) {
			if (S_ISDIR(new_inode->i_mode))
				clear_nlink(new_inode);
			else
				drop_nlink(new_inode);
		}
		if (S_ISDIR(old_inode->i_mode)) {
			if (!new_inode)
				inc_nlink(new_dir);
			drop_nlink(old_dir);
		}
1028
		v9fs_invalidate_inode_attr(old_inode);
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1030
		v9fs_invalidate_inode_attr(old_dir);
		v9fs_invalidate_inode_attr(new_dir);
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		/* successful rename */
		d_move(old_dentry, new_dentry);
1034
	}
1035
	up_write(&v9ses->rename_sem);
1036
	p9_client_clunk(newdirfid);
1037

1038
clunk_olddir:
1039
	p9_client_clunk(olddirfid);
1040