dir.c

LINUX1.0内核源代码,学习LINUX编程的一定要看。

	memcpy(name,__name,len);
	name[len] = '\0';
	if (len == 1 && name[0] == '.') { /* cheat for "." */
		*result = dir;
		return 0;
	}
	if ((NFS_SERVER(dir)->flags & NFS_MOUNT_NOAC)
	    || !nfs_lookup_cache_lookup(dir, name, &fhandle, &fattr)) {
		if ((error = nfs_proc_lookup(NFS_SERVER(dir), NFS_FH(dir),
		    name, &fhandle, &fattr))) {
			iput(dir);
			return error;
		}
		nfs_lookup_cache_add(dir, name, &fhandle, &fattr);
	}
	if (!(*result = nfs_fhget(dir->i_sb, &fhandle, &fattr))) {
		iput(dir);
		return -EACCES;
	}
	iput(dir);
	return 0;
}

static int nfs_create(struct inode *dir, const char *name, int len, int mode,
		      struct inode **result)
{
	struct nfs_sattr sattr;
	struct nfs_fattr fattr;
	struct nfs_fh fhandle;
	int error;

	*result = NULL;
	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("nfs_create: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (len > NFS_MAXNAMLEN) {
		iput(dir);
		return -ENAMETOOLONG;
	}
	sattr.mode = mode;
	sattr.uid = sattr.gid = sattr.size = (unsigned) -1;
	sattr.atime.seconds = sattr.mtime.seconds = (unsigned) -1;
	if ((error = nfs_proc_create(NFS_SERVER(dir), NFS_FH(dir),
		name, &sattr, &fhandle, &fattr))) {
		iput(dir);
		return error;
	}
	if (!(*result = nfs_fhget(dir->i_sb, &fhandle, &fattr))) {
		iput(dir);
		return -EACCES;
	}
	nfs_lookup_cache_add(dir, name, &fhandle, &fattr);
	iput(dir);
	return 0;
}

static int nfs_mknod(struct inode *dir, const char *name, int len,
		     int mode, int rdev)
{
	struct nfs_sattr sattr;
	struct nfs_fattr fattr;
	struct nfs_fh fhandle;
	int error;

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("nfs_mknod: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (len > NFS_MAXNAMLEN) {
		iput(dir);
		return -ENAMETOOLONG;
	}
	sattr.mode = mode;
	sattr.uid = sattr.gid = (unsigned) -1;
	if (S_ISCHR(mode) || S_ISBLK(mode))
		sattr.size = rdev; /* get out your barf bag */
	else
		sattr.size = (unsigned) -1;
	sattr.atime.seconds = sattr.mtime.seconds = (unsigned) -1;
	error = nfs_proc_create(NFS_SERVER(dir), NFS_FH(dir),
		name, &sattr, &fhandle, &fattr);
	if (!error)
		nfs_lookup_cache_add(dir, name, &fhandle, &fattr);
	iput(dir);
	return error;
}

static int nfs_mkdir(struct inode *dir, const char *name, int len, int mode)
{
	struct nfs_sattr sattr;
	struct nfs_fattr fattr;
	struct nfs_fh fhandle;
	int error;

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("nfs_mkdir: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (len > NFS_MAXNAMLEN) {
		iput(dir);
		return -ENAMETOOLONG;
	}
	sattr.mode = mode;
	sattr.uid = sattr.gid = sattr.size = (unsigned) -1;
	sattr.atime.seconds = sattr.mtime.seconds = (unsigned) -1;
	error = nfs_proc_mkdir(NFS_SERVER(dir), NFS_FH(dir),
		name, &sattr, &fhandle, &fattr);
	if (!error)
		nfs_lookup_cache_add(dir, name, &fhandle, &fattr);
	iput(dir);
	return error;
}

static int nfs_rmdir(struct inode *dir, const char *name, int len)
{
	int error;

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("nfs_rmdir: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (len > NFS_MAXNAMLEN) {
		iput(dir);
		return -ENAMETOOLONG;
	}
	error = nfs_proc_rmdir(NFS_SERVER(dir), NFS_FH(dir), name);
	if (!error)
		nfs_lookup_cache_remove(dir, NULL, name);
	iput(dir);
	return error;
}

static int nfs_unlink(struct inode *dir, const char *name, int len)
{
	int error;

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("nfs_unlink: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (len > NFS_MAXNAMLEN) {
		iput(dir);
		return -ENAMETOOLONG;
	}
	error = nfs_proc_remove(NFS_SERVER(dir), NFS_FH(dir), name);
	if (!error)
		nfs_lookup_cache_remove(dir, NULL, name);
	iput(dir);
	return error;
}

static int nfs_symlink(struct inode *dir, const char *name, int len,
		       const char *symname)
{
	struct nfs_sattr sattr;
	int error;

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("nfs_symlink: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (len > NFS_MAXNAMLEN) {
		iput(dir);
		return -ENAMETOOLONG;
	}
	if (strlen(symname) > NFS_MAXPATHLEN) {
		iput(dir);
		return -ENAMETOOLONG;
	}
	sattr.mode = S_IFLNK | S_IRWXUGO; /* SunOS 4.1.2 crashes without this! */
	sattr.uid = sattr.gid = sattr.size = (unsigned) -1;
	sattr.atime.seconds = sattr.mtime.seconds = (unsigned) -1;
	error = nfs_proc_symlink(NFS_SERVER(dir), NFS_FH(dir),
		name, symname, &sattr);
	iput(dir);
	return error;
}

static int nfs_link(struct inode *oldinode, struct inode *dir,
		    const char *name, int len)
{
	int error;

	if (!oldinode) {
		printk("nfs_link: old inode is NULL\n");
		iput(oldinode);
		iput(dir);
		return -ENOENT;
	}
	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("nfs_link: dir is NULL or not a directory\n");
		iput(oldinode);
		iput(dir);
		return -ENOENT;
	}
	if (len > NFS_MAXNAMLEN) {
		iput(oldinode);
		iput(dir);
		return -ENAMETOOLONG;
	}
	error = nfs_proc_link(NFS_SERVER(oldinode), NFS_FH(oldinode),
		NFS_FH(dir), name);
	if (!error)
		nfs_lookup_cache_remove(dir, oldinode, NULL);
	iput(oldinode);
	iput(dir);
	return error;
}

static int nfs_rename(struct inode *old_dir, const char *old_name, int old_len,
		      struct inode *new_dir, const char *new_name, int new_len)
{
	int error;

	if (!old_dir || !S_ISDIR(old_dir->i_mode)) {
		printk("nfs_rename: old inode is NULL or not a directory\n");
		iput(old_dir);
		iput(new_dir);
		return -ENOENT;
	}
	if (!new_dir || !S_ISDIR(new_dir->i_mode)) {
		printk("nfs_rename: new inode is NULL or not a directory\n");
		iput(old_dir);
		iput(new_dir);
		return -ENOENT;
	}
	if (old_len > NFS_MAXNAMLEN || new_len > NFS_MAXNAMLEN) {
		iput(old_dir);
		iput(new_dir);
		return -ENAMETOOLONG;
	}
	error = nfs_proc_rename(NFS_SERVER(old_dir),
		NFS_FH(old_dir), old_name,
		NFS_FH(new_dir), new_name);
	if (!error) {
		nfs_lookup_cache_remove(old_dir, NULL, old_name);
		nfs_lookup_cache_remove(new_dir, NULL, new_name);
	}
	iput(old_dir);
	iput(new_dir);
	return error;
}

/*
 * Many nfs protocol calls return the new file attributes after
 * an operation.  Here we update the inode to reflect the state
 * of the server's inode.
 */

void nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
{
	int was_empty;

	if (!inode || !fattr) {
		printk("nfs_refresh_inode: inode or fattr is NULL\n");
		return;
	}
	if (inode->i_ino != fattr->fileid) {
		printk("nfs_refresh_inode: inode number mismatch\n");
		return;
	}
	was_empty = inode->i_mode == 0;
	inode->i_mode = fattr->mode;
	inode->i_nlink = fattr->nlink;
	inode->i_uid = fattr->uid;
	inode->i_gid = fattr->gid;
	inode->i_size = fattr->size;
	inode->i_blksize = fattr->blocksize;
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		inode->i_rdev = fattr->rdev;
	else
		inode->i_rdev = 0;
	inode->i_blocks = fattr->blocks;
	inode->i_atime = fattr->atime.seconds;
	inode->i_mtime = fattr->mtime.seconds;
	inode->i_ctime = fattr->ctime.seconds;
	if (was_empty) {
		if (S_ISREG(inode->i_mode))
			inode->i_op = &nfs_file_inode_operations;
		else if (S_ISDIR(inode->i_mode))
			inode->i_op = &nfs_dir_inode_operations;
		else if (S_ISLNK(inode->i_mode))
			inode->i_op = &nfs_symlink_inode_operations;
		else if (S_ISCHR(inode->i_mode))
			inode->i_op = &chrdev_inode_operations;
		else if (S_ISBLK(inode->i_mode))
			inode->i_op = &blkdev_inode_operations;
		else if (S_ISFIFO(inode->i_mode))
			init_fifo(inode);
		else
			inode->i_op = NULL;
	}
	nfs_lookup_cache_refresh(inode, fattr);
}