NFSv4.2: improve page handling for GETXATTR (a1f26739) · Commits · 戴 / test

fs/nfs/nfs42proc.c

+36 −11

Original line number	Diff line number	Diff line
		@@ -1173,14 +1173,12 @@ static int _nfs42_proc_setxattr(struct inode inode, const char name,
		}

		static ssize_t _nfs42_proc_getxattr(struct inode inode, const char name,
		void *buf, size_t buflen)
		void buf, size_t buflen, struct page *pages,
		size_t plen)
		{
		struct nfs_server *server = NFS_SERVER(inode);
		struct page *pages[NFS4XATTR_MAXPAGES] = {};
		struct nfs42_getxattrargs arg = {
		.fh = NFS_FH(inode),
		.xattr_pages = pages,
		.xattr_len = buflen,
		.xattr_name = name,
		};
		struct nfs42_getxattrres res;
		@@ -1189,7 +1187,10 @@ static ssize_t _nfs42_proc_getxattr(struct inode inode, const char name,
		.rpc_argp = &arg,
		.rpc_resp = &res,
		};
		int ret, np;
		ssize_t ret;

		arg.xattr_len = plen;
		arg.xattr_pages = pages;

		ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
		&res.seq_res, 0);
		@@ -1214,10 +1215,6 @@ static ssize_t _nfs42_proc_getxattr(struct inode inode, const char name,
		_copy_from_pages(buf, pages, 0, res.xattr_len);
		}

		np = DIV_ROUND_UP(res.xattr_len, PAGE_SIZE);
		while (--np >= 0)
		__free_page(pages[np]);

		return res.xattr_len;
		}

		@@ -1292,16 +1289,44 @@ ssize_t nfs42_proc_getxattr(struct inode inode, const char name,
		void *buf, size_t buflen)
		{
		struct nfs4_exception exception = { };
		ssize_t err;
		ssize_t err, np, i;
		struct page **pages;

		np = nfs_page_array_len(0, buflen ?: XATTR_SIZE_MAX);
		pages = kmalloc_array(np, sizeof(*pages), GFP_KERNEL);
		if (!pages)
		return -ENOMEM;

		for (i = 0; i < np; i++) {
		pages[i] = alloc_page(GFP_KERNEL);
		if (!pages[i]) {
		np = i + 1;
		goto out;
		}
		}

		/*
		* The GETXATTR op has no length field in the call, and the
		* xattr data is at the end of the reply.
		*
		* There is no downside in using the page-aligned length. It will
		* allow receiving and caching xattrs that are too large for the
		* caller but still fit in the page-rounded value.
		*/
		do {
		err = _nfs42_proc_getxattr(inode, name, buf, buflen);
		err = _nfs42_proc_getxattr(inode, name, buf, buflen,
		pages, np * PAGE_SIZE);
		if (err >= 0)
		break;
		err = nfs4_handle_exception(NFS_SERVER(inode), err,
		&exception);
		} while (exception.retry);

		out:
		while (--np >= 0)
		__free_page(pages[np]);
		kfree(pages);

		return err;
		}

fs/nfs/nfs42xdr.c

+8 −5

Original line number	Diff line number	Diff line
		@@ -489,6 +489,12 @@ static int decode_getxattr(struct xdr_stream *xdr,
		return -EIO;

		len = be32_to_cpup(p);

		/*
		* Only check against the page length here. The actual
		* requested length may be smaller, but that is only
		* checked against after possibly caching a valid reply.
		*/
		if (len > req->rq_rcv_buf.page_len)
		return -ERANGE;

		@@ -1477,7 +1483,6 @@ static void nfs4_xdr_enc_getxattr(struct rpc_rqst req, struct xdr_stream xdr,
		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
		};
		uint32_t replen;
		size_t plen;

		encode_compound_hdr(xdr, req, &hdr);
		encode_sequence(xdr, &args->seq_args, &hdr);
		@@ -1485,10 +1490,8 @@ static void nfs4_xdr_enc_getxattr(struct rpc_rqst req, struct xdr_stream xdr,
		replen = hdr.replen + op_decode_hdr_maxsz + 1;
		encode_getxattr(xdr, args->xattr_name, &hdr);

		plen = args->xattr_len ? args->xattr_len : XATTR_SIZE_MAX;

		rpc_prepare_reply_pages(req, args->xattr_pages, 0, plen, replen);
		req->rq_rcv_buf.flags \|= XDRBUF_SPARSE_PAGES;
		rpc_prepare_reply_pages(req, args->xattr_pages, 0, args->xattr_len,
		replen);

		encode_nops(&hdr);
		}

Admin message