vfs_inode.c

	wstat.name = (char *) new_dentry->d_name.name;
	retval = p9_client_wstat(oldfid, &wstat);

clunk_newdir:
	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);
		}
		v9fs_invalidate_inode_attr(old_inode);
		v9fs_invalidate_inode_attr(old_dir);
		v9fs_invalidate_inode_attr(new_dir);

		/* successful rename */
		d_move(old_dentry, new_dentry);
	}
	up_write(&v9ses->rename_sem);
	p9_client_clunk(newdirfid);

clunk_olddir:
	p9_client_clunk(olddirfid);

done:
	return retval;
}

/**
 * v9fs_vfs_getattr - retrieve file metadata
 * @mnt: mount information
 * @dentry: file to get attributes on
 * @stat: metadata structure to populate
 *
 */

static int
v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
		 struct kstat *stat)
{
	int err;
	struct v9fs_session_info *v9ses;
	struct p9_fid *fid;
	struct p9_wstat *st;

	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
	err = -EPERM;
	v9ses = v9fs_dentry2v9ses(dentry);
	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
		generic_fillattr(dentry->d_inode, stat);
		return 0;
	}
	fid = v9fs_fid_lookup(dentry);
	if (IS_ERR(fid))
		return PTR_ERR(fid);

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

	v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
	generic_fillattr(dentry->d_inode, stat);

	p9stat_free(st);
	kfree(st);
	return 0;
}

/**
 * v9fs_vfs_setattr - set file metadata
 * @dentry: file whose metadata to set
 * @iattr: metadata assignment structure
 *
 */

static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
{
	int retval;
	struct v9fs_session_info *v9ses;
	struct p9_fid *fid;
	struct p9_wstat wstat;

	p9_debug(P9_DEBUG_VFS, "\n");
	retval = inode_change_ok(dentry->d_inode, iattr);
	if (retval)
		return retval;

	retval = -EPERM;
	v9ses = v9fs_dentry2v9ses(dentry);
	fid = v9fs_fid_lookup(dentry);
	if(IS_ERR(fid))
		return PTR_ERR(fid);

	v9fs_blank_wstat(&wstat);
	if (iattr->ia_valid & ATTR_MODE)
		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);

	if (iattr->ia_valid & ATTR_MTIME)
		wstat.mtime = iattr->ia_mtime.tv_sec;

	if (iattr->ia_valid & ATTR_ATIME)
		wstat.atime = iattr->ia_atime.tv_sec;

	if (iattr->ia_valid & ATTR_SIZE)
		wstat.length = iattr->ia_size;

	if (v9fs_proto_dotu(v9ses)) {
		if (iattr->ia_valid & ATTR_UID)
			wstat.n_uid = iattr->ia_uid;

		if (iattr->ia_valid & ATTR_GID)
			wstat.n_gid = iattr->ia_gid;
	}

	/* Write all dirty data */
	if (S_ISREG(dentry->d_inode->i_mode))
		filemap_write_and_wait(dentry->d_inode->i_mapping);

	retval = p9_client_wstat(fid, &wstat);
	if (retval < 0)
		return retval;

	if ((iattr->ia_valid & ATTR_SIZE) &&
	    iattr->ia_size != i_size_read(dentry->d_inode))
		truncate_setsize(dentry->d_inode, iattr->ia_size);

	v9fs_invalidate_inode_attr(dentry->d_inode);

	setattr_copy(dentry->d_inode, iattr);
	mark_inode_dirty(dentry->d_inode);
	return 0;
}

/**
 * v9fs_stat2inode - populate an inode structure with mistat info
 * @stat: Plan 9 metadata (mistat) structure
 * @inode: inode to populate
 * @sb: superblock of filesystem
 *
 */

void
v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
	struct super_block *sb)
{
	umode_t mode;
	char ext[32];
	char tag_name[14];
	unsigned int i_nlink;
	struct v9fs_session_info *v9ses = sb->s_fs_info;
	struct v9fs_inode *v9inode = V9FS_I(inode);

	set_nlink(inode, 1);

	inode->i_atime.tv_sec = stat->atime;
	inode->i_mtime.tv_sec = stat->mtime;
	inode->i_ctime.tv_sec = stat->mtime;

	inode->i_uid = v9ses->dfltuid;
	inode->i_gid = v9ses->dfltgid;

	if (v9fs_proto_dotu(v9ses)) {
		inode->i_uid = stat->n_uid;
		inode->i_gid = stat->n_gid;
	}
	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
			/*
			 * Hadlink support got added later to
			 * to the .u extension. So there can be
			 * server out there that doesn't support
			 * this even with .u extension. So check
			 * for non NULL stat->extension
			 */
			strncpy(ext, stat->extension, sizeof(ext));
			/* HARDLINKCOUNT %u */
			sscanf(ext, "%13s %u", tag_name, &i_nlink);
			if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
				set_nlink(inode, i_nlink);
		}
	}
	mode = p9mode2perm(v9ses, stat);
	mode |= inode->i_mode & ~S_IALLUGO;
	inode->i_mode = mode;
	i_size_write(inode, stat->length);

	/* not real number of blocks, but 512 byte ones ... */
	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
}

/**
 * v9fs_qid2ino - convert qid into inode number
 * @qid: qid to hash
 *
 * BUG: potential for inode number collisions?
 */

ino_t v9fs_qid2ino(struct p9_qid *qid)
{
	u64 path = qid->path + 2;
	ino_t i = 0;

	if (sizeof(ino_t) == sizeof(path))
		memcpy(&i, &path, sizeof(ino_t));
	else
		i = (ino_t) (path ^ (path >> 32));

	return i;
}

/**
 * v9fs_readlink - read a symlink's location (internal version)
 * @dentry: dentry for symlink
 * @buffer: buffer to load symlink location into
 * @buflen: length of buffer
 *
 */

static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
{
	int retval;

	struct v9fs_session_info *v9ses;
	struct p9_fid *fid;
	struct p9_wstat *st;

	p9_debug(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
	retval = -EPERM;
	v9ses = v9fs_dentry2v9ses(dentry);
	fid = v9fs_fid_lookup(dentry);
	if (IS_ERR(fid))
		return PTR_ERR(fid);

	if (!v9fs_proto_dotu(v9ses))
		return -EBADF;

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

	if (!(st->mode & P9_DMSYMLINK)) {
		retval = -EINVAL;
		goto done;
	}

	/* copy extension buffer into buffer */
	strncpy(buffer, st->extension, buflen);

	p9_debug(P9_DEBUG_VFS, "%s -> %s (%s)\n",
		 dentry->d_name.name, st->extension, buffer);

	retval = strnlen(buffer, buflen);
done:
	p9stat_free(st);
	kfree(st);
	return retval;
}

/**
 * v9fs_vfs_follow_link - follow a symlink path
 * @dentry: dentry for symlink
 * @nd: nameidata
 *
 */

static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
	int len = 0;
	char *link = __getname();

	p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);

	if (!link)
		link = ERR_PTR(-ENOMEM);
	else {
		len = v9fs_readlink(dentry, link, PATH_MAX);

		if (len < 0) {
			__putname(link);
			link = ERR_PTR(len);
		} else
			link[min(len, PATH_MAX-1)] = 0;
	}
	nd_set_link(nd, link);

	return NULL;
}

/**
 * v9fs_vfs_put_link - release a symlink path
 * @dentry: dentry for symlink
 * @nd: nameidata
 * @p: unused
 *
 */

void
v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
{
	char *s = nd_get_link(nd);

	p9_debug(P9_DEBUG_VFS, " %s %s\n",
		 dentry->d_name.name, IS_ERR(s) ? "<error>" : s);
	if (!IS_ERR(s))
		__putname(s);
}

/**
 * v9fs_vfs_mkspecial - create a special file
 * @dir: inode to create special file in
 * @dentry: dentry to create
 * @mode: mode to create special file
 * @extension: 9p2000.u format extension string representing special file
 *
 */

static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
	u32 perm, const char *extension)
{
	struct p9_fid *fid;
	struct v9fs_session_info *v9ses;

	v9ses = v9fs_inode2v9ses(dir);
	if (!v9fs_proto_dotu(v9ses)) {
		p9_debug(P9_DEBUG_ERROR, "not extended\n");
		return -EPERM;
	}

	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
								P9_OREAD);
	if (IS_ERR(fid))
		return PTR_ERR(fid);

	v9fs_invalidate_inode_attr(dir);
	p9_client_clunk(fid);
	return 0;
}

/**
 * v9fs_vfs_symlink - helper function to create symlinks
 * @dir: directory inode containing symlink
 * @dentry: dentry for symlink
 * @symname: symlink data
 *
 * See Also: 9P2000.u RFC for more information
 *
 */

static int
v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
	p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
		 dir->i_ino, dentry->d_name.name, symname);

	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
}

/**
 * v9fs_vfs_link - create a hardlink
 * @old_dentry: dentry for file to link to
 * @dir: inode destination for new link
 * @dentry: dentry for link
 *
 */

static int
v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
	      struct dentry *dentry)
{
	int retval;
	char *name;
	struct p9_fid *oldfid;

	p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
		 dir->i_ino, dentry->d_name.name, old_dentry->d_name.name);

	oldfid = v9fs_fid_clone(old_dentry);
	if (IS_ERR(oldfid))
		return PTR_ERR(oldfid);

	name = __getname();
	if (unlikely(!name)) {
		retval = -ENOMEM;
		goto clunk_fid;
	}

	sprintf(name, "%d\n", oldfid->fid);
	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
	__putname(name);
	if (!retval) {
		v9fs_refresh_inode(oldfid, old_dentry->d_inode);
		v9fs_invalidate_inode_attr(dir);
	}
clunk_fid:
	p9_client_clunk(oldfid);
	return retval;
}

/**
 * v9fs_vfs_mknod - create a special file
 * @dir: inode destination for new link
 * @dentry: dentry for file
 * @mode: mode for creation
 * @rdev: device associated with special file
 *
 */

static int
v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
{
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
	int retval;
	char *name;
	u32 perm;

	p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %hx MAJOR: %u MINOR: %u\n",
		 dir->i_ino, dentry->d_name.name, mode,
		 MAJOR(rdev), MINOR(rdev));

	if (!new_valid_dev(rdev))
		return -EINVAL;

	name = __getname();
	if (!name)
		return -ENOMEM;
	/* build extension */
	if (S_ISBLK(mode))
		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
	else if (S_ISCHR(mode))
		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
	else if (S_ISFIFO(mode))
		*name = 0;
	else if (S_ISSOCK(mode))
		*name = 0;
	else {
		__putname(name);
		return -EINVAL;
	}

	perm = unixmode2p9mode(v9ses, mode);
	retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
	__putname(name);

	return retval;
}

int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
{
	int umode;
	dev_t rdev;
	loff_t i_size;
	struct p9_wstat *st;
	struct v9fs_session_info *v9ses;

	v9ses = v9fs_inode2v9ses(inode);
	st = p9_client_stat(fid);
	if (IS_ERR(st))
		return PTR_ERR(st);
	/*
	 * Don't update inode if the file type is different
	 */
	umode = p9mode2unixmode(v9ses, st, &rdev);
	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
		goto out;

	spin_lock(&inode->i_lock);
	/*
	 * We don't want to refresh inode->i_size,
	 * because we may have cached data
	 */
	i_size = inode->i_size;
	v9fs_stat2inode(st, inode, inode->i_sb);
	if (v9ses->cache)
		inode->i_size = i_size;
	spin_unlock(&inode->i_lock);
out:
	p9stat_free(st);
	kfree(st);
	return 0;
}

static const struct inode_operations v9fs_dir_inode_operations_dotu = {
	.create = v9fs_vfs_create,
	.lookup = v9fs_vfs_lookup,
	.symlink = v9fs_vfs_symlink,
	.link = v9fs_vfs_link,
	.unlink = v9fs_vfs_unlink,
	.mkdir = v9fs_vfs_mkdir,
	.rmdir = v9fs_vfs_rmdir,
	.mknod = v9fs_vfs_mknod,
	.rename = v9fs_vfs_rename,
	.getattr = v9fs_vfs_getattr,
	.setattr = v9fs_vfs_setattr,
};

static const struct inode_operations v9fs_dir_inode_operations = {
	.create = v9fs_vfs_create,
	.lookup = v9fs_vfs_lookup,
	.unlink = v9fs_vfs_unlink,
	.mkdir = v9fs_vfs_mkdir,
	.rmdir = v9fs_vfs_rmdir,
	.mknod = v9fs_vfs_mknod,
	.rename = v9fs_vfs_rename,
	.getattr = v9fs_vfs_getattr,
	.setattr = v9fs_vfs_setattr,
};

static const struct inode_operations v9fs_file_inode_operations = {
	.getattr = v9fs_vfs_getattr,
	.setattr = v9fs_vfs_setattr,
};

static const struct inode_operations v9fs_symlink_inode_operations = {
	.readlink = generic_readlink,
	.follow_link = v9fs_vfs_follow_link,
	.put_link = v9fs_vfs_put_link,
	.getattr = v9fs_vfs_getattr,
	.setattr = v9fs_vfs_setattr,
};