/* The file offset position is now represented as a true offset into the
 * page cache as is the case in most of the other filesystems.
 */
static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct dentry	*dentry = filp->f_dentry;
	struct inode	*inode = dentry->d_inode;
	nfs_readdir_descriptor_t my_desc,
			*desc = &my_desc;
	struct nfs_entry my_entry;
	long		res;

	res = nfs_revalidate(dentry);
	if (res < 0)
		return res;

	/*
	 * filp->f_pos points to the file offset in the page cache.
	 * but if the cache has meanwhile been zapped, we need to
	 * read from the last dirent to revalidate f_pos
	 * itself.
	 */
	memset(desc, 0, sizeof(*desc));
	memset(&my_entry, 0, sizeof(my_entry));

	desc->file = filp;
	desc->target = filp->f_pos;
	desc->entry = &my_entry;
	desc->decode = NFS_PROTO(inode)->decode_dirent;

	while(!desc->entry->eof) {
		res = readdir_search_pagecache(desc);
		if (res == -EBADCOOKIE) {
			/* This means either end of directory */
			if (desc->entry->cookie != desc->target) {
				/* Or that the server has 'lost' a cookie */
				res = uncached_readdir(desc, dirent, filldir);
				if (res >= 0)
					continue;
			}
			res = 0;
			break;
		} else if (res < 0)
			break;

		res = nfs_do_filldir(desc, dirent, filldir);
		if (res < 0) {
			res = 0;
			break;
		}
	}
	if (desc->error < 0)
		return desc->error;
	if (res < 0)
		return res;
	return 0;
}
コード例 #2
0
/*
 * If we cannot find a cookie in our cache, we suspect that this is
 * because it points to a deleted file, so we ask the server to return
 * whatever it thinks is the next entry. We then feed this to filldir.
 * If all goes well, we should then be able to find our way round the
 * cache on the next call to readdir_search_pagecache();
 *
 * NOTE: we cannot add the anonymous page to the pagecache because
 *	 the data it contains might not be page aligned. Besides,
 *	 we should already have a complete representation of the
 *	 directory in the page cache by the time we get here.
 */
static inline
int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
		     filldir_t filldir)
{
	struct file	*file = desc->file;
	struct inode	*inode = file->f_dentry->d_inode;
	struct rpc_cred	*cred = nfs_file_cred(file);
	struct page	*page = NULL;
	int		status;

	dfprintk(VFS, "NFS: uncached_readdir() searching for cookie %Lu\n", (long long)desc->target);

	page = alloc_page(GFP_HIGHUSER);
	if (!page) {
		status = -ENOMEM;
		goto out;
	}
	desc->error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, desc->target,
						page,
						NFS_SERVER(inode)->dtsize,
						desc->plus);
	NFS_FLAGS(inode) |= NFS_INO_INVALID_ATIME;
	desc->page = page;
	desc->ptr = kmap(page);		/* matching kunmap in nfs_do_filldir */
	if (desc->error >= 0) {
		if ((status = dir_decode(desc)) == 0)
			desc->entry->prev_cookie = desc->target;
	} else
		status = -EIO;
	if (status < 0)
		goto out_release;

	status = nfs_do_filldir(desc, dirent, filldir);

	/* Reset read descriptor so it searches the page cache from
	 * the start upon the next call to readdir_search_pagecache() */
	desc->page_index = 0;
	desc->entry->cookie = desc->entry->prev_cookie = 0;
	desc->entry->eof = 0;
 out:
	dfprintk(VFS, "NFS: uncached_readdir() returns %d\n", status);
	return status;
 out_release:
	dir_page_release(desc);
	goto out;
}
コード例 #3
0
/* The file offset position is now represented as a true offset into the
 * page cache as is the case in most of the other filesystems.
 */
static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct dentry	*dentry = filp->f_dentry;
	struct inode	*inode = dentry->d_inode;
	nfs_readdir_descriptor_t my_desc,
			*desc = &my_desc;
	struct nfs_entry my_entry;
	struct nfs_fh	 fh;
	struct nfs_fattr fattr;
	long		res;

	lock_kernel();

	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (res < 0) {
		unlock_kernel();
		return res;
	}

	/*
	 * filp->f_pos points to the file offset in the page cache.
	 * but if the cache has meanwhile been zapped, we need to
	 * read from the last dirent to revalidate f_pos
	 * itself.
	 */
	memset(desc, 0, sizeof(*desc));

	desc->file = filp;
	desc->target = filp->f_pos;
	desc->decode = NFS_PROTO(inode)->decode_dirent;
	desc->plus = NFS_USE_READDIRPLUS(inode);

	my_entry.cookie = my_entry.prev_cookie = 0;
	my_entry.eof = 0;
	my_entry.fh = &fh;
	my_entry.fattr = &fattr;
	desc->entry = &my_entry;

	while(!desc->entry->eof) {
		res = readdir_search_pagecache(desc);
		if (res == -EBADCOOKIE) {
			/* This means either end of directory */
			if (desc->entry->cookie != desc->target) {
				/* Or that the server has 'lost' a cookie */
				res = uncached_readdir(desc, dirent, filldir);
				if (res >= 0)
					continue;
			}
			res = 0;
			break;
		}
		if (res == -ETOOSMALL && desc->plus) {
			NFS_FLAGS(inode) &= ~NFS_INO_ADVISE_RDPLUS;
			nfs_zap_caches(inode);
			desc->plus = 0;
			desc->entry->eof = 0;
			continue;
		}
		if (res < 0)
			break;

		res = nfs_do_filldir(desc, dirent, filldir);
		if (res < 0) {
			res = 0;
			break;
		}
	}
	unlock_kernel();
	if (desc->error < 0)
		return desc->error;
	if (res < 0)
		return res;
	return 0;
}