From ee4cb30dd9d2bfa50bcad7b2d8732af3e61a0a9c Mon Sep 17 00:00:00 2001
From: David Disseldorp <ddiss@suse.de>
Date: Mon, 24 Aug 2015 00:32:00 +0200
Subject: [PATCH] ceph/osd_client: add support for CEPH_OSD_OP_GETXATTR
Patch-mainline: Not yet, SES clustered LIO/RBD
References: fate#318836 bsc#1139101

Allows for xattr retrieval. Response data buffer allocation is the
responsibility of the osd_req_op_xattr_init() caller.

Signed-off-by: David Disseldorp <ddiss@suse.de>
[luis: adjusted context due to commit 33165d472310 ("libceph: introduce
 ceph_pagelist_alloc()")]
Acked-by: Luis Henriques <lhenriques@suse.com>
[luis: updated get_num_data_items() introduced by commit 0d9c1ab3be4c
 ("libceph: preallocate message data items")]
[luis: rebased atop 26f887e0a3c4 ("libceph, rbd, ceph: move
 ceph_osdc_alloc_messages() calls")]
[ddiss: use single request data item for cmp/setxattr]
---
 include/linux/ceph/osd_client.h |    8 ++++-
 net/ceph/osd_client.c           |   59 ++++++++++++++++++++++++++++++++--------
 2 files changed, 55 insertions(+), 12 deletions(-)

--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -109,7 +109,8 @@ struct ceph_osd_req_op {
 			u32 value_len;
 			__u8 cmp_op;       /* CEPH_OSD_CMPXATTR_OP_* */
 			__u8 cmp_mode;     /* CEPH_OSD_CMPXATTR_MODE_* */
-			struct ceph_osd_data osd_data;
+			struct ceph_osd_data request_data;
+			struct ceph_osd_data response_data;
 		} xattr;
 		struct {
 			const char *class_name;
@@ -401,6 +402,11 @@ extern void osd_req_op_raw_data_in_pages
 					unsigned int which,
 					struct page **pages, u64 length,
 					u32 alignment, bool pages_from_pool,
+					bool own_pages);
+extern void osd_req_op_xattr_response_data_pages(struct ceph_osd_request *,
+					unsigned int which,
+					struct page **pages, u64 length,
+					u32 alignment, bool pages_from_pool,
 					bool own_pages);
 
 extern void osd_req_op_writesame_init(struct ceph_osd_request *osd_req,
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -369,6 +369,18 @@ void osd_req_op_writesame_osd_data_sg(st
 }
 EXPORT_SYMBOL(osd_req_op_writesame_osd_data_sg);
 
+void osd_req_op_xattr_response_data_pages(struct ceph_osd_request *osd_req,
+			unsigned int which, struct page **pages, u64 length,
+			u32 alignment, bool pages_from_pool, bool own_pages)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_data(osd_req, which, xattr, response_data);
+	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
+				pages_from_pool, own_pages);
+}
+EXPORT_SYMBOL(osd_req_op_xattr_response_data_pages);
+
 static u64 ceph_osd_data_length(struct ceph_osd_data *osd_data)
 {
 	switch (osd_data->type) {
@@ -431,7 +443,11 @@ static void osd_req_op_data_release(stru
 		break;
 	case CEPH_OSD_OP_SETXATTR:
 	case CEPH_OSD_OP_CMPXATTR:
-		ceph_osd_data_release(&op->xattr.osd_data);
+		ceph_osd_data_release(&op->xattr.request_data);
+		break;
+	case CEPH_OSD_OP_GETXATTR:
+		ceph_osd_data_release(&op->xattr.request_data);
+		ceph_osd_data_release(&op->xattr.response_data);
 		break;
 	case CEPH_OSD_OP_STAT:
 		ceph_osd_data_release(&op->raw_data_in);
@@ -752,6 +768,7 @@ static void get_num_data_items(struct ce
 			break;
 
 		/* both */
+		case CEPH_OSD_OP_GETXATTR:
 		case CEPH_OSD_OP_NOTIFY:
 			*num_request_data_items += 1;
 			*num_reply_data_items += 1;
@@ -938,29 +955,42 @@ int osd_req_op_xattr_init(struct ceph_os
 {
 	struct ceph_osd_req_op *op = _osd_req_op_init(osd_req, which,
 						      opcode, 0);
-	struct ceph_pagelist *pagelist;
+	struct ceph_pagelist *req_pagelist;
 	size_t payload_len;
+	int ret;
 
-	BUG_ON(opcode != CEPH_OSD_OP_SETXATTR && opcode != CEPH_OSD_OP_CMPXATTR);
+	BUG_ON(opcode != CEPH_OSD_OP_SETXATTR
+		&& opcode != CEPH_OSD_OP_CMPXATTR
+		&& opcode != CEPH_OSD_OP_GETXATTR);
 
-	pagelist = ceph_pagelist_alloc(GFP_NOFS);
-	if (!pagelist)
+	req_pagelist = ceph_pagelist_alloc(GFP_NOFS);
+	if (!req_pagelist)
 		return -ENOMEM;
 
 	payload_len = strlen(name);
 	op->xattr.name_len = payload_len;
-	ceph_pagelist_append(pagelist, name, payload_len);
+	ret = ceph_pagelist_append(req_pagelist, name, payload_len);
+	if (ret) {
+		goto err_reqpl_free;
+	}
 
-	op->xattr.value_len = size;
-	ceph_pagelist_append(pagelist, value, size);
-	payload_len += size;
+	if (value) {
+		op->xattr.value_len = size;
+		ceph_pagelist_append(req_pagelist, value, size);
+		payload_len += size;
+	}
 
 	op->xattr.cmp_op = cmp_op;
 	op->xattr.cmp_mode = cmp_mode;
 
-	ceph_osd_data_pagelist_init(&op->xattr.osd_data, pagelist);
+	ceph_osd_data_pagelist_init(&op->xattr.request_data, req_pagelist);
 	op->indata_len = payload_len;
+
 	return 0;
+
+err_reqpl_free:
+	ceph_pagelist_release(req_pagelist);
+	return ret;
 }
 EXPORT_SYMBOL(osd_req_op_xattr_init);
 
@@ -1077,6 +1107,7 @@ static u32 osd_req_encode_op(struct ceph
 		break;
 	case CEPH_OSD_OP_SETXATTR:
 	case CEPH_OSD_OP_CMPXATTR:
+	case CEPH_OSD_OP_GETXATTR:
 		dst->xattr.name_len = cpu_to_le32(src->xattr.name_len);
 		dst->xattr.value_len = cpu_to_le32(src->xattr.value_len);
 		dst->xattr.cmp_op = src->xattr.cmp_op;
@@ -2022,7 +2053,7 @@ static void setup_request_data(struct ce
 			WARN_ON(op->indata_len != op->xattr.name_len +
 						  op->xattr.value_len);
 			ceph_osdc_msg_data_add(request_msg,
-					       &op->xattr.osd_data);
+					       &op->xattr.request_data);
 			break;
 		case CEPH_OSD_OP_NOTIFY_ACK:
 			ceph_osdc_msg_data_add(request_msg,
@@ -2063,6 +2094,12 @@ static void setup_request_data(struct ce
 			ceph_osdc_msg_data_add(reply_msg,
 					       &op->notify.response_data);
 			break;
+		case CEPH_OSD_OP_GETXATTR:
+			WARN_ON(op->indata_len != op->xattr.name_len);
+			ceph_osdc_msg_data_add(request_msg,
+					       &op->xattr.request_data);
+			ceph_osdc_msg_data_add(reply_msg,
+					       &op->xattr.response_data);
 		}
 	}
 }