Ejemplo n.º 1
0
/*
 * A check for whether or not the parent directory has changed.
 * In the case it has, we assume that the dentries are untrustworthy
 * and may need to be looked up again.
 */
static inline int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
{
	if (IS_ROOT(dentry))
		return 1;
	if ((NFS_FLAGS(dir) & NFS_INO_INVALID_ATTR) != 0
			|| nfs_attribute_timeout(dir))
		return 0;
	return nfs_verify_change_attribute(dir, (unsigned long)dentry->d_fsdata);
}
Ejemplo n.º 2
0
/**
 * nfs_revalidate_file - Revalidate the page cache & related metadata
 * @inode - pointer to inode struct
 * @file - pointer to file
 */
static int nfs_revalidate_file(struct inode *inode, struct file *filp)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	int retval = 0;

	if ((nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) || nfs_attribute_timeout(inode))
		retval = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
	nfs_revalidate_mapping(inode, filp->f_mapping);
	return 0;
}
Ejemplo n.º 3
0
/*
 * Use the cached Readdirplus results in order to avoid a LOOKUP call
 * whenever we believe that the parent directory has not changed.
 *
 * We assume that any file creation/rename changes the directory mtime.
 * As this results in a page cache invalidation whenever it occurs,
 * we don't require any other tests for cache coherency.
 */
static
int nfs_cached_lookup(struct inode *dir, struct dentry *dentry,
			struct nfs_fh *fh, struct nfs_fattr *fattr)
{
	nfs_readdir_descriptor_t desc;
	struct nfs_server *server;
	struct nfs_entry entry;
	struct page *page;
	unsigned long timestamp;
	int res;

	if (!NFS_USE_READDIRPLUS(dir))
		return -ENOENT;
	server = NFS_SERVER(dir);
	/* Don't use readdirplus unless the cache is stable */
	if ((server->flags & NFS_MOUNT_NOAC) != 0
			|| nfs_caches_unstable(dir)
			|| nfs_attribute_timeout(dir))
		return -ENOENT;
	if ((NFS_FLAGS(dir) & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA)) != 0)
		return -ENOENT;
	timestamp = NFS_I(dir)->readdir_timestamp;

	entry.fh = fh;
	entry.fattr = fattr;

	desc.decode = NFS_PROTO(dir)->decode_dirent;
	desc.entry = &entry;
	desc.page_index = 0;
	desc.plus = 1;

	for(;(page = find_get_page(dir->i_mapping, desc.page_index)); desc.page_index++) {

		res = -EIO;
		if (PageUptodate(page)) {
			void * kaddr = kmap_atomic(page, KM_USER0);
			desc.ptr = kaddr;
			res = find_dirent_name(&desc, page, dentry);
			kunmap_atomic(kaddr, KM_USER0);
		}
		page_cache_release(page);

		if (res == 0)
			goto out_found;
		if (res != -EAGAIN)
			break;
	}
	return -ENOENT;
 out_found:
	fattr->timestamp = timestamp;
	return 0;
}
Ejemplo n.º 4
0
/**
 * nfs_revalidate_size - Revalidate the file size
 * @inode - pointer to inode struct
 * @file - pointer to struct file
 *
 * Revalidates the file length. This is basically a wrapper around
 * nfs_revalidate_inode() that takes into account the fact that we may
 * have cached writes (in which case we don't care about the server's
 * idea of what the file length is), or O_DIRECT (in which case we
 * shouldn't trust the cache).
 */
static int nfs_revalidate_file_size(struct inode *inode, struct file *filp)
{
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs_inode *nfsi = NFS_I(inode);

	if (server->flags & NFS_MOUNT_NOAC)
		goto force_reval;
	if (filp->f_flags & O_DIRECT)
		goto force_reval;
	if (nfsi->npages != 0)
		return 0;
	if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode))
		return 0;
force_reval:
	return __nfs_revalidate_inode(server, inode);
}
Ejemplo n.º 5
0
/**
 * nfs_revalidate_size - Revalidate the file size
 * @inode - pointer to inode struct
 * @file - pointer to struct file
 *
 * Revalidates the file length. This is basically a wrapper around
 * nfs_revalidate_inode() that takes into account the fact that we may
 * have cached writes (in which case we don't care about the server's
 * idea of what the file length is), or O_DIRECT (in which case we
 * shouldn't trust the cache).
 */
static int nfs_revalidate_file_size(struct inode *inode, struct file *filp)
{
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs_inode *nfsi = NFS_I(inode);

	if (nfs_have_delegated_attributes(inode))
		goto out_noreval;

	if (filp->f_flags & O_DIRECT)
		goto force_reval;
	if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
		goto force_reval;
	if (nfs_attribute_timeout(inode))
		goto force_reval;
out_noreval:
	return 0;
force_reval:
	return __nfs_revalidate_inode(server, inode);
}