inode.c

嵌入式系统设计与实验教材二源码linux内核移植与编译

		rpc_shutdown_client(server->client);
		goto nfsv3_try_again;
	}

	if (!root_inode)
		goto out_no_root;
	sb->s_root = d_alloc_root(root_inode);
	if (!sb->s_root)
		goto out_no_root;

	sb->s_root->d_op = &nfs_dentry_operations;

	/* Get some general file system info */
        if (server->rpc_ops->statfs(server, root, &fsinfo) >= 0) {
		if (server->namelen == 0)
			server->namelen = fsinfo.namelen;
	} else {
		printk(KERN_NOTICE "NFS: cannot retrieve file system info.\n");
		goto out_no_root;
        }

	/* Work out a lot of parameters */
	if (data->rsize == 0)
		server->rsize = nfs_block_size(fsinfo.rtpref, NULL);
	if (data->wsize == 0)
		server->wsize = nfs_block_size(fsinfo.wtpref, NULL);
	/* NFSv3: we don't have bsize, but rather rtmult and wtmult... */
	if (!fsinfo.bsize)
		fsinfo.bsize = (fsinfo.rtmult>fsinfo.wtmult) ? fsinfo.rtmult : fsinfo.wtmult;
	/* Also make sure we don't go below rsize/wsize since
	 * RPC calls are expensive */
	if (fsinfo.bsize < server->rsize)
		fsinfo.bsize = server->rsize;
	if (fsinfo.bsize < server->wsize)
		fsinfo.bsize = server->wsize;

	if (data->bsize == 0)
		sb->s_blocksize = nfs_block_bits(fsinfo.bsize, &sb->s_blocksize_bits);
	if (server->rsize > fsinfo.rtmax)
		server->rsize = fsinfo.rtmax;
	if (server->wsize > fsinfo.wtmax)
		server->wsize = fsinfo.wtmax;

	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
	if (server->rpages > NFS_READ_MAXIOV) {
		server->rpages = NFS_READ_MAXIOV;
		server->rsize = server->rpages << PAGE_CACHE_SHIFT;
	}

	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
        if (server->wpages > NFS_WRITE_MAXIOV) {
		server->wpages = NFS_WRITE_MAXIOV;
                server->wsize = server->wpages << PAGE_CACHE_SHIFT;
	}

	server->dtsize = nfs_block_size(fsinfo.dtpref, NULL);
	if (server->dtsize > PAGE_CACHE_SIZE)
		server->dtsize = PAGE_CACHE_SIZE;
	if (server->dtsize > server->rsize)
		server->dtsize = server->rsize;

        maxlen = (version == 2) ? NFS2_MAXNAMLEN : NFS3_MAXNAMLEN;

        if (server->namelen == 0 || server->namelen > maxlen)
                server->namelen = maxlen;

	sb->s_maxbytes = fsinfo.maxfilesize;

	/* Fire up the writeback cache */
	if (nfs_reqlist_alloc(server) < 0) {
		printk(KERN_NOTICE "NFS: cannot initialize writeback cache.\n");
		goto failure_kill_reqlist;
	}

	/* We're airborne */

	/* Check whether to start the lockd process */
	if (!(server->flags & NFS_MOUNT_NONLM))
		lockd_up();
	return sb;

	/* Yargs. It didn't work out. */
 failure_kill_reqlist:
	nfs_reqlist_exit(server);
out_no_root:
	printk("nfs_read_super: get root inode failed\n");
	iput(root_inode);
	rpciod_down();
	goto out_shutdown;

out_no_iod:
	printk(KERN_WARNING "NFS: couldn't start rpciod!\n");
out_shutdown:
	rpc_shutdown_client(server->client);
	goto out_free_host;

out_no_client:
	printk(KERN_WARNING "NFS: cannot create RPC client.\n");
	xprt_destroy(xprt);
	goto out_free_host;

out_no_xprt:
	printk(KERN_WARNING "NFS: cannot create RPC transport.\n");

out_free_host:
	nfs_reqlist_free(server);
	kfree(server->hostname);
out_unlock:
	goto out_fail;

out_no_remote:
	printk("NFS: mount program didn't pass remote address!\n");
	goto out_fail;

out_miss_args:
	printk("nfs_read_super: missing data argument\n");

out_fail:
	return NULL;
}

static int
nfs_statfs(struct super_block *sb, struct statfs *buf)
{
	struct nfs_server *server = &sb->u.nfs_sb.s_server;
	unsigned char blockbits;
	unsigned long blockres;
	struct nfs_fsinfo res;
	int error;

	error = server->rpc_ops->statfs(server, NFS_FH(sb->s_root->d_inode), &res);
	buf->f_type = NFS_SUPER_MAGIC;
	if (error < 0)
		goto out_err;

	if (res.bsize == 0)
		res.bsize = sb->s_blocksize;
	buf->f_bsize = nfs_block_bits(res.bsize, &blockbits);
	blockres = (1 << blockbits) - 1;
	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
	buf->f_bavail = (res.abytes + blockres) >> blockbits;
	buf->f_files = res.tfiles;
	buf->f_ffree = res.afiles;
	if (res.namelen == 0 || res.namelen > server->namelen)
		res.namelen = server->namelen;
	buf->f_namelen = res.namelen;
	return 0;
 out_err:
	printk("nfs_statfs: statfs error = %d\n", -error);
	buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1;
	return 0;
}

static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
{
	static struct proc_nfs_info {
		int flag;
		char *str;
		char *nostr;
	} nfs_info[] = {
		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
		{ NFS_MOUNT_INTR, ",intr", "" },
		{ NFS_MOUNT_POSIX, ",posix", "" },
		{ NFS_MOUNT_TCP, ",tcp", ",udp" },
		{ NFS_MOUNT_NOCTO, ",nocto", "" },
		{ NFS_MOUNT_NOAC, ",noac", "" },
		{ NFS_MOUNT_NONLM, ",nolock", ",lock" },
		{ NFS_MOUNT_BROKEN_SUID, ",broken_suid", "" },
		{ 0, NULL, NULL }
	};
	struct proc_nfs_info *nfs_infop;
	struct nfs_server *nfss = &mnt->mnt_sb->u.nfs_sb.s_server;

	seq_printf(m, ",v%d", nfss->rpc_ops->version);
	seq_printf(m, ",rsize=%d", nfss->rsize);
	seq_printf(m, ",wsize=%d", nfss->wsize);
	if (nfss->acregmin != 3*HZ)
		seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
	if (nfss->acregmax != 60*HZ)
		seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
	if (nfss->acdirmin != 30*HZ)
		seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
	if (nfss->acdirmax != 60*HZ)
		seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
		if (nfss->flags & nfs_infop->flag)
			seq_puts(m, nfs_infop->str);
		else
			seq_puts(m, nfs_infop->nostr);
	}
	seq_puts(m, ",addr=");
	seq_escape(m, nfss->hostname, " \t\n\\");
	return 0;
}

/*
 * Invalidate the local caches
 */
void
nfs_zap_caches(struct inode *inode)
{
	NFS_ATTRTIMEO(inode) = NFS_MINATTRTIMEO(inode);
	NFS_ATTRTIMEO_UPDATE(inode) = jiffies;

	invalidate_inode_pages(inode);

	memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
	NFS_CACHEINV(inode);
}

/*
 * Invalidate, but do not unhash, the inode
 */
static void
nfs_invalidate_inode(struct inode *inode)
{
	umode_t save_mode = inode->i_mode;

	make_bad_inode(inode);
	inode->i_mode = save_mode;
	nfs_zap_caches(inode);
}

/*
 * Fill in inode information from the fattr.
 */
static void
nfs_fill_inode(struct inode *inode, struct nfs_fh *fh, struct nfs_fattr *fattr)
{
	/*
	 * Check whether the mode has been set, as we only want to
	 * do this once. (We don't allow inodes to change types.)
	 */
	if (inode->i_mode == 0) {
		NFS_FILEID(inode) = fattr->fileid;
		NFS_FSID(inode) = fattr->fsid;
		inode->i_mode = fattr->mode;
		/* Why so? Because we want revalidate for devices/FIFOs, and
		 * that's precisely what we have in nfs_file_inode_operations.
		 */
		inode->i_op = &nfs_file_inode_operations;
		if (S_ISREG(inode->i_mode)) {
			inode->i_fop = &nfs_file_operations;
			inode->i_data.a_ops = &nfs_file_aops;
		} else if (S_ISDIR(inode->i_mode)) {
			inode->i_op = &nfs_dir_inode_operations;
			inode->i_fop = &nfs_dir_operations;
		} else if (S_ISLNK(inode->i_mode))
			inode->i_op = &nfs_symlink_inode_operations;
		else
			init_special_inode(inode, inode->i_mode, fattr->rdev);
		memcpy(&inode->u.nfs_i.fh, fh, sizeof(inode->u.nfs_i.fh));
	}
	nfs_refresh_inode(inode, fattr);
}

struct nfs_find_desc {
	struct nfs_fh		*fh;
	struct nfs_fattr	*fattr;
};

/*
 * In NFSv3 we can have 64bit inode numbers. In order to support
 * this, and re-exported directories (also seen in NFSv2)
 * we are forced to allow 2 different inodes to have the same
 * i_ino.
 */
static int
nfs_find_actor(struct inode *inode, unsigned long ino, void *opaque)
{
	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
	struct nfs_fh		*fh = desc->fh;
	struct nfs_fattr	*fattr = desc->fattr;

	if (NFS_FSID(inode) != fattr->fsid)
		return 0;
	if (NFS_FILEID(inode) != fattr->fileid)
		return 0;
	if (memcmp(&inode->u.nfs_i.fh, fh, sizeof(inode->u.nfs_i.fh)) != 0)
		return 0;
	/* Force an attribute cache update if inode->i_count == 0 */
	if (!atomic_read(&inode->i_count))
		NFS_CACHEINV(inode);
	return 1;
}

int
nfs_inode_is_stale(struct inode *inode, struct nfs_fh *fh, struct nfs_fattr *fattr)
{
	/* Empty inodes are not stale */
	if (!inode->i_mode)
		return 0;

	if ((fattr->mode & S_IFMT) != (inode->i_mode & S_IFMT))
		return 1;

	if (is_bad_inode(inode) || NFS_STALE(inode))
		return 1;

	/* Has the filehandle changed? If so is the old one stale? */
	if (memcmp(&inode->u.nfs_i.fh, fh, sizeof(inode->u.nfs_i.fh)) != 0 &&
	    __nfs_revalidate_inode(NFS_SERVER(inode),inode) == -ESTALE)
		return 1;

	return 0;
}

/*
 * This is our own version of iget that looks up inodes by file handle
 * instead of inode number.  We use this technique instead of using
 * the vfs read_inode function because there is no way to pass the
 * file handle or current attributes into the read_inode function.
 *
 */
struct inode *
nfs_fhget(struct dentry *dentry, struct nfs_fh *fhandle,
				 struct nfs_fattr *fattr)
{
	struct super_block *sb = dentry->d_sb;

	dprintk("NFS: nfs_fhget(%s/%s fileid=%Ld)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		(long long)fattr->fileid);
	return __nfs_fhget(sb, fhandle, fattr);
}

/*
 * Look up the inode by super block and fattr->fileid.
 */
static struct inode *
__nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
{
	struct nfs_find_desc desc = { fh, fattr };
	struct inode *inode = NULL;
	unsigned long ino;

	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
		goto out_no_inode;

	if (!fattr->nlink) {
		printk("NFS: Buggy server - nlink == 0!\n");
		goto out_no_inode;
	}

	ino = nfs_fattr_to_ino_t(fattr);

	if (!(inode = iget4(sb, ino, nfs_find_actor, &desc)))
		goto out_no_inode;

	nfs_fill_inode(inode, fh, fattr);
	dprintk("NFS: __nfs_fhget(%x/%Ld ct=%d)\n",
		inode->i_dev, (long long)NFS_FILEID(inode),
		atomic_read(&inode->i_count));

out:
	return inode;

out_no_inode:
	printk("__nfs_fhget: iget failed\n");
	goto out;
}

int
nfs_notify_change(struct dentry *dentry, struct iattr *attr)
{
	struct inode *inode = dentry->d_inode;
	struct nfs_fattr fattr;
	int error;

	/*
	 * Make sure the inode is up-to-date.
	 */
	error = nfs_revalidate(dentry);
	if (error) {
#ifdef NFS_PARANOIA
printk("nfs_notify_change: revalidate failed, error=%d\n", error);
#endif
		goto out;
	}

	if (!S_ISREG(inode->i_mode))
		attr->ia_valid &= ~ATTR_SIZE;

	filemap_fdatasync(inode->i_mapping);
	error = nfs_wb_all(inode);
	filemap_fdatawait(inode->i_mapping);
	if (error)
		goto out;

	error = NFS_PROTO(inode)->setattr(inode, &fattr, attr);
	if (error)
		goto out;
	/*
	 * If we changed the size or mtime, update the inode
	 * now to avoid invalidating the page cache.
	 */
	if (attr->ia_valid & ATTR_SIZE) {