[PATCH 00/15] rbd: support for data-pool + obj_request->object_no

[PATCH 00/15] rbd: support for data-pool + obj_request->object_no

[Ilya Dryomov]

Hello,

There are two pieces here: support for RBD_FEATURE_DATA_POOL (patches
1-10) and a couple of cleanups / minor optimizations that build on it
and allow us to get rid of rbd_segment_name_cache (patches 11 - 15).

Thanks,

                Ilya


Ilya Dryomov (15):
  rbd: use kstrndup() in rbd_header_from_disk()
  rbd: kill rbd_image_header::{crypt_type,comp_type}
  rbd: initialize rbd_dev->header_oloc early
  rbd: do away with obj_request in rbd_obj_read_sync()
  libceph: pass reply buffer length through ceph_osdc_call()
  rbd: switch rbd_obj_method_sync() to ceph_osdc_call()
  rbd: remove now unused rbd_obj_request_wait() and helpers
  rbd: use rbd_obj_bytes() more
  rbd: introduce rbd_init_layout()
  rbd: support for data-pool feature
  rbd: set offset and length outside of rbd_obj_request_create()
  rbd: factor out __rbd_osd_req_create()
  rbd: RBD_V{1,2}_DATA_FORMAT macros
  rbd: store and use obj_request->object_no
  rbd: kill obj_request->object_name and rbd_segment_name_cache

 drivers/block/rbd.c         | 601 +++++++++++++++++---------------------------
 drivers/block/rbd_types.h   |  10 +-
 include/linux/ceph/osdmap.h |   7 -
 net/ceph/cls_lock_client.c  |   2 +-
 net/ceph/osd_client.c       |   7 +-
 5 files changed, 238 insertions(+), 389 deletions(-)

-- 
2.4.3

[PATCH 01/15] rbd: use kstrndup() in rbd_header_from_disk()

[Ilya Dryomov]

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 40a15ae354ce..76e538c3378e 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -992,15 +992,11 @@ static int rbd_header_from_disk(struct rbd_device *rbd_dev,
 	/* Allocate this now to avoid having to handle failure below */
 
 	if (first_time) {
-		size_t len;
-
-		len = strnlen(ondisk->object_prefix,
-				sizeof (ondisk->object_prefix));
-		object_prefix = kmalloc(len + 1, GFP_KERNEL);
+		object_prefix = kstrndup(ondisk->object_prefix,
+					 sizeof(ondisk->object_prefix),
+					 GFP_KERNEL);
 		if (!object_prefix)
 			return -ENOMEM;
-		memcpy(object_prefix, ondisk->object_prefix, len);
-		object_prefix[len] = '\0';
 	}
 
 	/* Allocate the snapshot context and fill it in */
-- 
2.4.3

[PATCH 02/15] rbd: kill rbd_image_header::{crypt_type,comp_type}

[Ilya Dryomov]

Image format 1 is deprecated and format 2 doesn't have these.  Also,
__rbd_dev_create() takes care of zeroing (or otherwise initializing)
format 2 specific fields.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c       | 9 ---------
 drivers/block/rbd_types.h | 3 ---
 2 files changed, 12 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 76e538c3378e..a6ad714c85ac 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -144,8 +144,6 @@ struct rbd_image_header {
 	/* These six fields never change for a given rbd image */
 	char *object_prefix;
 	__u8 obj_order;
-	__u8 crypt_type;
-	__u8 comp_type;
 	u64 stripe_unit;
 	u64 stripe_count;
 	u64 features;		/* Might be changeable someday? */
@@ -1047,12 +1045,6 @@ static int rbd_header_from_disk(struct rbd_device *rbd_dev,
 	if (first_time) {
 		header->object_prefix = object_prefix;
 		header->obj_order = ondisk->options.order;
-		header->crypt_type = ondisk->options.crypt_type;
-		header->comp_type = ondisk->options.comp_type;
-		/* The rest aren't used for format 1 images */
-		header->stripe_unit = 0;
-		header->stripe_count = 0;
-		header->features = 0;
 	} else {
 		ceph_put_snap_context(header->snapc);
 		kfree(header->snap_names);
@@ -5938,7 +5930,6 @@ static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
 		if (ret < 0)
 			goto out_err;
 	}
-	/* No support for crypto and compression type format 2 images */
 
 	return 0;
 out_err:
diff --git a/drivers/block/rbd_types.h b/drivers/block/rbd_types.h
index 94f367db27b0..be9c76d292f5 100644
--- a/drivers/block/rbd_types.h
+++ b/drivers/block/rbd_types.h
@@ -57,9 +57,6 @@ enum rbd_notify_op {
 #define RBD_MIN_OBJ_ORDER       16
 #define RBD_MAX_OBJ_ORDER       30
 
-#define RBD_COMP_NONE		0
-#define RBD_CRYPT_NONE		0
-
 #define RBD_HEADER_TEXT		"<<< Rados Block Device Image >>>\n"
 #define RBD_HEADER_SIGNATURE	"RBD"
 #define RBD_HEADER_VERSION	"001.005"
-- 
2.4.3

[PATCH 03/15] rbd: initialize rbd_dev->header_oloc early

[Ilya Dryomov]

No reason to delay it until image_id is known.  This will be required
by some rbd_obj_method_sync() callers, after rbd_obj_method_sync() is
changed to take oloc.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index a6ad714c85ac..24e8116d3431 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4863,7 +4863,7 @@ static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
 	init_rwsem(&rbd_dev->header_rwsem);
 
 	ceph_oid_init(&rbd_dev->header_oid);
-	ceph_oloc_init(&rbd_dev->header_oloc);
+	rbd_dev->header_oloc.pool = spec->pool_id;
 
 	mutex_init(&rbd_dev->watch_mutex);
 	rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
@@ -6062,8 +6062,6 @@ static int rbd_dev_header_name(struct rbd_device *rbd_dev)
 	/* Record the header object name for this rbd image. */
 
 	rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
-
-	rbd_dev->header_oloc.pool = rbd_dev->layout.pool_id;
 	if (rbd_dev->image_format == 1)
 		ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
 				       spec->image_name, RBD_SUFFIX);
-- 
2.4.3

[PATCH 04/15] rbd: do away with obj_request in rbd_obj_read_sync()

[Ilya Dryomov]

rbd_obj_request machinery is completely unnecessary here; all that's
being done is fetching a metadata object - no striping, cloning, etc.
More importantly, rbd_osd_req_create() grabs pool id from layout and
that is becoming a data pool id.

Kill offset argument - all metadata objects are small and read in full.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 81 +++++++++++++++++++++--------------------------------
 1 file changed, 32 insertions(+), 49 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 24e8116d3431..e55e26f7e4d8 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4242,63 +4242,46 @@ static void rbd_free_disk(struct rbd_device *rbd_dev)
 }
 
 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
-				const char *object_name,
-				u64 offset, u64 length, void *buf)
+			     struct ceph_object_id *oid,
+			     struct ceph_object_locator *oloc,
+			     void *buf, int buf_len)
 
 {
-	struct rbd_obj_request *obj_request;
-	struct page **pages = NULL;
-	u32 page_count;
-	size_t size;
+	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+	struct ceph_osd_request *req;
+	struct page **pages;
+	int num_pages = calc_pages_for(0, buf_len);
 	int ret;
 
-	page_count = (u32) calc_pages_for(offset, length);
-	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
-	if (IS_ERR(pages))
-		return PTR_ERR(pages);
-
-	ret = -ENOMEM;
-	obj_request = rbd_obj_request_create(object_name, offset, length,
-							OBJ_REQUEST_PAGES);
-	if (!obj_request)
-		goto out;
-
-	obj_request->pages = pages;
-	obj_request->page_count = page_count;
-
-	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
-						  obj_request);
-	if (!obj_request->osd_req)
-		goto out;
+	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
 
-	osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
-					offset, length, 0, 0);
-	osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
-					obj_request->pages,
-					obj_request->length,
-					obj_request->offset & ~PAGE_MASK,
-					false, false);
+	ceph_oid_copy(&req->r_base_oid, oid);
+	ceph_oloc_copy(&req->r_base_oloc, oloc);
+	req->r_flags = CEPH_OSD_FLAG_READ;
 
-	rbd_obj_request_submit(obj_request);
-	ret = rbd_obj_request_wait(obj_request);
+	ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
 	if (ret)
-		goto out;
+		goto out_req;
 
-	ret = obj_request->result;
-	if (ret < 0)
-		goto out;
+	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
+	if (IS_ERR(pages)) {
+		ret = PTR_ERR(pages);
+		goto out_req;
+	}
 
-	rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
-	size = (size_t) obj_request->xferred;
-	ceph_copy_from_page_vector(pages, buf, 0, size);
-	rbd_assert(size <= (size_t)INT_MAX);
-	ret = (int)size;
-out:
-	if (obj_request)
-		rbd_obj_request_put(obj_request);
-	else
-		ceph_release_page_vector(pages, page_count);
+	osd_req_op_extent_init(req, 0, CEPH_OSD_OP_READ, 0, buf_len, 0, 0);
+	osd_req_op_extent_osd_data_pages(req, 0, pages, buf_len, 0, false,
+					 true);
+
+	ceph_osdc_start_request(osdc, req, false);
+	ret = ceph_osdc_wait_request(osdc, req);
+	if (ret >= 0)
+		ceph_copy_from_page_vector(pages, buf, 0, ret);
 
+out_req:
+	ceph_osdc_put_request(req);
 	return ret;
 }
 
@@ -4334,8 +4317,8 @@ static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
 		if (!ondisk)
 			return -ENOMEM;
 
-		ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_oid.name,
-				       0, size, ondisk);
+		ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
+					&rbd_dev->header_oloc, ondisk, size);
 		if (ret < 0)
 			goto out;
 		if ((size_t)ret < size) {
-- 
2.4.3

[PATCH 05/15] libceph: pass reply buffer length through ceph_osdc_call()

[Ilya Dryomov]

To spare checking for "this reply fits into a page, but does it fit
into my buffer?" in some callers, osd_req_op_cls_response_data_pages()
needs to know how big it is.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 net/ceph/cls_lock_client.c | 2 +-
 net/ceph/osd_client.c      | 7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/net/ceph/cls_lock_client.c b/net/ceph/cls_lock_client.c
index 50f040fdb2a9..f13a1ea87459 100644
--- a/net/ceph/cls_lock_client.c
+++ b/net/ceph/cls_lock_client.c
@@ -278,7 +278,7 @@ int ceph_cls_lock_info(struct ceph_osd_client *osdc,
 	int get_info_op_buf_size;
 	int name_len = strlen(lock_name);
 	struct page *get_info_op_page, *reply_page;
-	size_t reply_len;
+	size_t reply_len = PAGE_SIZE;
 	void *p, *end;
 	int ret;
 
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 3a2417bb6ff0..ac4753421d0c 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -4023,7 +4023,7 @@ EXPORT_SYMBOL(ceph_osdc_maybe_request_map);
  * Execute an OSD class method on an object.
  *
  * @flags: CEPH_OSD_FLAG_*
- * @resp_len: out param for reply length
+ * @resp_len: in/out param for reply length
  */
 int ceph_osdc_call(struct ceph_osd_client *osdc,
 		   struct ceph_object_id *oid,
@@ -4036,6 +4036,9 @@ int ceph_osdc_call(struct ceph_osd_client *osdc,
 	struct ceph_osd_request *req;
 	int ret;
 
+	if (req_len > PAGE_SIZE || (resp_page && *resp_len > PAGE_SIZE))
+		return -E2BIG;
+
 	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
 	if (!req)
 		return -ENOMEM;
@@ -4054,7 +4057,7 @@ int ceph_osdc_call(struct ceph_osd_client *osdc,
 						  0, false, false);
 	if (resp_page)
 		osd_req_op_cls_response_data_pages(req, 0, &resp_page,
-						   PAGE_SIZE, 0, false, false);
+						   *resp_len, 0, false, false);
 
 	ceph_osdc_start_request(osdc, req, false);
 	ret = ceph_osdc_wait_request(osdc, req);
-- 
2.4.3

[PATCH 06/15] rbd: switch rbd_obj_method_sync() to ceph_osdc_call()

[Ilya Dryomov]

As explained in the previous commit, rbd_obj_request machinery (and
rbd_osd_req_create() in particular) shouldn't be used for working with
metadata objects.

Switch to the recently added ceph_osdc_call().  It assumes single pages
for outbound and inbound buffers, but that's OK - none of the callers
need more than that.  These pages need to be allocated (messenger is in
dire need of proper iterator interface!), but we are swapping for
pages[] and pagelist allocations in the existing code.

Kill class_name argument - all rbd methods are under "rbd".

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 162 ++++++++++++++++++++++------------------------------
 1 file changed, 67 insertions(+), 95 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index e55e26f7e4d8..2967b50b48fc 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3971,17 +3971,17 @@ static void rbd_reregister_watch(struct work_struct *work)
  * returned in the outbound buffer, or a negative error code.
  */
 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
-			     const char *object_name,
-			     const char *class_name,
+			     struct ceph_object_id *oid,
+			     struct ceph_object_locator *oloc,
 			     const char *method_name,
 			     const void *outbound,
 			     size_t outbound_size,
 			     void *inbound,
 			     size_t inbound_size)
 {
-	struct rbd_obj_request *obj_request;
-	struct page **pages;
-	u32 page_count;
+	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+	struct page *req_page = NULL;
+	struct page *reply_page;
 	int ret;
 
 	/*
@@ -3991,61 +3991,35 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
 	 * method.  Currently if this is present it will be a
 	 * snapshot id.
 	 */
-	page_count = (u32)calc_pages_for(0, inbound_size);
-	pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
-	if (IS_ERR(pages))
-		return PTR_ERR(pages);
+	if (outbound) {
+		if (outbound_size > PAGE_SIZE)
+			return -E2BIG;
 
-	ret = -ENOMEM;
-	obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
-							OBJ_REQUEST_PAGES);
-	if (!obj_request)
-		goto out;
-
-	obj_request->pages = pages;
-	obj_request->page_count = page_count;
-
-	obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
-						  obj_request);
-	if (!obj_request->osd_req)
-		goto out;
-
-	osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
-					class_name, method_name);
-	if (outbound_size) {
-		struct ceph_pagelist *pagelist;
-
-		pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
-		if (!pagelist)
-			goto out;
+		req_page = alloc_page(GFP_KERNEL);
+		if (!req_page)
+			return -ENOMEM;
 
-		ceph_pagelist_init(pagelist);
-		ceph_pagelist_append(pagelist, outbound, outbound_size);
-		osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
-						pagelist);
+		memcpy(page_address(req_page), outbound, outbound_size);
 	}
-	osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
-					obj_request->pages, inbound_size,
-					0, false, false);
 
-	rbd_obj_request_submit(obj_request);
-	ret = rbd_obj_request_wait(obj_request);
-	if (ret)
-		goto out;
-
-	ret = obj_request->result;
-	if (ret < 0)
-		goto out;
+	reply_page = alloc_page(GFP_KERNEL);
+	if (!reply_page) {
+		if (req_page)
+			__free_page(req_page);
+		return -ENOMEM;
+	}
 
-	rbd_assert(obj_request->xferred < (u64)INT_MAX);
-	ret = (int)obj_request->xferred;
-	ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
-out:
-	if (obj_request)
-		rbd_obj_request_put(obj_request);
-	else
-		ceph_release_page_vector(pages, page_count);
+	ret = ceph_osdc_call(osdc, oid, oloc, RBD_DRV_NAME, method_name,
+			     CEPH_OSD_FLAG_READ, req_page, outbound_size,
+			     reply_page, &inbound_size);
+	if (!ret) {
+		memcpy(inbound, page_address(reply_page), inbound_size);
+		ret = inbound_size;
+	}
 
+	if (req_page)
+		__free_page(req_page);
+	__free_page(reply_page);
 	return ret;
 }
 
@@ -4939,10 +4913,10 @@ static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
 		__le64 size;
 	} __attribute__ ((packed)) size_buf = { 0 };
 
-	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
-				"rbd", "get_size",
-				&snapid, sizeof (snapid),
-				&size_buf, sizeof (size_buf));
+	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+				  &rbd_dev->header_oloc, "get_size",
+				  &snapid, sizeof(snapid),
+				  &size_buf, sizeof(size_buf));
 	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
 	if (ret < 0)
 		return ret;
@@ -4979,9 +4953,9 @@ static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
 	if (!reply_buf)
 		return -ENOMEM;
 
-	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
-				"rbd", "get_object_prefix", NULL, 0,
-				reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
+	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+				  &rbd_dev->header_oloc, "get_object_prefix",
+				  NULL, 0, reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
 	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
 	if (ret < 0)
 		goto out;
@@ -5014,10 +4988,10 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
 	u64 unsup;
 	int ret;
 
-	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
-				"rbd", "get_features",
-				&snapid, sizeof (snapid),
-				&features_buf, sizeof (features_buf));
+	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+				  &rbd_dev->header_oloc, "get_features",
+				  &snapid, sizeof(snapid),
+				  &features_buf, sizeof(features_buf));
 	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
 	if (ret < 0)
 		return ret;
@@ -5076,10 +5050,9 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
 	}
 
 	snapid = cpu_to_le64(rbd_dev->spec->snap_id);
-	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
-				"rbd", "get_parent",
-				&snapid, sizeof (snapid),
-				reply_buf, size);
+	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+				  &rbd_dev->header_oloc, "get_parent",
+				  &snapid, sizeof(snapid), reply_buf, size);
 	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
 	if (ret < 0)
 		goto out_err;
@@ -5179,9 +5152,9 @@ static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
 	u64 stripe_count;
 	int ret;
 
-	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
-				"rbd", "get_stripe_unit_count", NULL, 0,
-				(char *)&striping_info_buf, size);
+	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+				&rbd_dev->header_oloc, "get_stripe_unit_count",
+				NULL, 0, &striping_info_buf, size);
 	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
 	if (ret < 0)
 		return ret;
@@ -5218,6 +5191,7 @@ static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
 
 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
 {
+	CEPH_DEFINE_OID_ONSTACK(oid);
 	size_t image_id_size;
 	char *image_id;
 	void *p;
@@ -5245,10 +5219,10 @@ static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
 	if (!reply_buf)
 		goto out;
 
-	ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
-				"rbd", "dir_get_name",
-				image_id, image_id_size,
-				reply_buf, size);
+	ceph_oid_printf(&oid, "%s", RBD_DIRECTORY);
+	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
+				  "dir_get_name", image_id, image_id_size,
+				  reply_buf, size);
 	if (ret < 0)
 		goto out;
 	p = reply_buf;
@@ -5427,9 +5401,9 @@ static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
 	if (!reply_buf)
 		return -ENOMEM;
 
-	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
-				"rbd", "get_snapcontext", NULL, 0,
-				reply_buf, size);
+	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+				  &rbd_dev->header_oloc, "get_snapcontext",
+				  NULL, 0, reply_buf, size);
 	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
 	if (ret < 0)
 		goto out;
@@ -5492,10 +5466,9 @@ static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
 		return ERR_PTR(-ENOMEM);
 
 	snapid = cpu_to_le64(snap_id);
-	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
-				"rbd", "get_snapshot_name",
-				&snapid, sizeof (snapid),
-				reply_buf, size);
+	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+				  &rbd_dev->header_oloc, "get_snapshot_name",
+				  &snapid, sizeof(snapid), reply_buf, size);
 	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
 	if (ret < 0) {
 		snap_name = ERR_PTR(ret);
@@ -5802,7 +5775,7 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev)
 {
 	int ret;
 	size_t size;
-	char *object_name;
+	CEPH_DEFINE_OID_ONSTACK(oid);
 	void *response;
 	char *image_id;
 
@@ -5822,12 +5795,12 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev)
 	 * First, see if the format 2 image id file exists, and if
 	 * so, get the image's persistent id from it.
 	 */
-	size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
-	object_name = kmalloc(size, GFP_NOIO);
-	if (!object_name)
-		return -ENOMEM;
-	sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
-	dout("rbd id object name is %s\n", object_name);
+	ret = ceph_oid_aprintf(&oid, GFP_KERNEL, "%s%s", RBD_ID_PREFIX,
+			       rbd_dev->spec->image_name);
+	if (ret)
+		return ret;
+
+	dout("rbd id object name is %s\n", oid.name);
 
 	/* Response will be an encoded string, which includes a length */
 
@@ -5840,9 +5813,9 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev)
 
 	/* If it doesn't exist we'll assume it's a format 1 image */
 
-	ret = rbd_obj_method_sync(rbd_dev, object_name,
-				"rbd", "get_id", NULL, 0,
-				response, RBD_IMAGE_ID_LEN_MAX);
+	ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
+				  "get_id", NULL, 0,
+				  response, RBD_IMAGE_ID_LEN_MAX);
 	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
 	if (ret == -ENOENT) {
 		image_id = kstrdup("", GFP_KERNEL);
@@ -5865,8 +5838,7 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev)
 	}
 out:
 	kfree(response);
-	kfree(object_name);
-
+	ceph_oid_destroy(&oid);
 	return ret;
 }
 
-- 
2.4.3

[PATCH 07/15] rbd: remove now unused rbd_obj_request_wait() and helpers

[Ilya Dryomov]

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 38 --------------------------------------
 1 file changed, 38 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 2967b50b48fc..68036c29c07c 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1619,44 +1619,6 @@ static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
 	ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
 }
 
-static void rbd_obj_request_end(struct rbd_obj_request *obj_request)
-{
-	dout("%s %p\n", __func__, obj_request);
-	ceph_osdc_cancel_request(obj_request->osd_req);
-}
-
-/*
- * Wait for an object request to complete.  If interrupted, cancel the
- * underlying osd request.
- *
- * @timeout: in jiffies, 0 means "wait forever"
- */
-static int __rbd_obj_request_wait(struct rbd_obj_request *obj_request,
-				  unsigned long timeout)
-{
-	long ret;
-
-	dout("%s %p\n", __func__, obj_request);
-	ret = wait_for_completion_interruptible_timeout(
-					&obj_request->completion,
-					ceph_timeout_jiffies(timeout));
-	if (ret <= 0) {
-		if (ret == 0)
-			ret = -ETIMEDOUT;
-		rbd_obj_request_end(obj_request);
-	} else {
-		ret = 0;
-	}
-
-	dout("%s %p ret %d\n", __func__, obj_request, (int)ret);
-	return ret;
-}
-
-static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
-{
-	return __rbd_obj_request_wait(obj_request, 0);
-}
-
 static void rbd_img_request_complete(struct rbd_img_request *img_request)
 {
 
-- 
2.4.3

[PATCH 08/15] rbd: use rbd_obj_bytes() more

[Ilya Dryomov]

Returning u64 doesn't make sense: max header->obj_order is 25 and
ceph_file_layout::object_size is u32.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 68036c29c07c..f2f52b7db33d 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -971,6 +971,14 @@ static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
 }
 
 /*
+ * returns the size of an object in the image
+ */
+static u32 rbd_obj_bytes(struct rbd_image_header *header)
+{
+	return 1U << header->obj_order;
+}
+
+/*
  * Fill an rbd image header with information from the given format 1
  * on-disk header.
  */
@@ -1255,7 +1263,7 @@ static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
 
 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
 {
-	u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
+	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
 
 	return offset & (segment_size - 1);
 }
@@ -1263,7 +1271,7 @@ static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
 				u64 offset, u64 length)
 {
-	u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
+	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
 
 	offset &= segment_size - 1;
 
@@ -1275,14 +1283,6 @@ static u64 rbd_segment_length(struct rbd_device *rbd_dev,
 }
 
 /*
- * returns the size of an object in the image
- */
-static u64 rbd_obj_bytes(struct rbd_image_header *header)
-{
-	return 1 << header->obj_order;
-}
-
-/*
  * bio helpers
  */
 
@@ -2721,7 +2721,7 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
 	 * child image to which the original request was to be sent.
 	 */
 	img_offset = obj_request->img_offset - obj_request->offset;
-	length = (u64)1 << rbd_dev->header.obj_order;
+	length = rbd_obj_bytes(&rbd_dev->header);
 
 	/*
 	 * There is no defined parent data beyond the parent
@@ -5130,7 +5130,7 @@ static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
 	 * out, and only fail if the image has non-default values.
 	 */
 	ret = -EINVAL;
-	obj_size = (u64)1 << rbd_dev->header.obj_order;
+	obj_size = rbd_obj_bytes(&rbd_dev->header);
 	p = &striping_info_buf;
 	stripe_unit = ceph_decode_64(&p);
 	if (stripe_unit != obj_size) {
-- 
2.4.3

[PATCH 09/15] rbd: introduce rbd_init_layout()

[Ilya Dryomov]

Rather than initializing layout fields with some made up values in
__rbd_dev_create(), move the initialization into rbd_init_layout() and
call it after the header is actually populated.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index f2f52b7db33d..aac1d3259738 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -978,6 +978,21 @@ static u32 rbd_obj_bytes(struct rbd_image_header *header)
 	return 1U << header->obj_order;
 }
 
+static void rbd_init_layout(struct rbd_device *rbd_dev)
+{
+	if (rbd_dev->header.stripe_unit == 0 ||
+	    rbd_dev->header.stripe_count == 0) {
+		rbd_dev->header.stripe_unit = rbd_obj_bytes(&rbd_dev->header);
+		rbd_dev->header.stripe_count = 1;
+	}
+
+	rbd_dev->layout.stripe_unit = rbd_dev->header.stripe_unit;
+	rbd_dev->layout.stripe_count = rbd_dev->header.stripe_count;
+	rbd_dev->layout.object_size = rbd_obj_bytes(&rbd_dev->header);
+	rbd_dev->layout.pool_id = rbd_dev->spec->pool_id;
+	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
+}
+
 /*
  * Fill an rbd image header with information from the given format 1
  * on-disk header.
@@ -1053,6 +1068,7 @@ static int rbd_header_from_disk(struct rbd_device *rbd_dev,
 	if (first_time) {
 		header->object_prefix = object_prefix;
 		header->obj_order = ondisk->options.order;
+		rbd_init_layout(rbd_dev);
 	} else {
 		ceph_put_snap_context(header->snapc);
 		kfree(header->snap_names);
@@ -4804,12 +4820,6 @@ static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
 	rbd_dev->rbd_client = rbdc;
 	rbd_dev->spec = spec;
 
-	rbd_dev->layout.stripe_unit = 1 << RBD_MAX_OBJ_ORDER;
-	rbd_dev->layout.stripe_count = 1;
-	rbd_dev->layout.object_size = 1 << RBD_MAX_OBJ_ORDER;
-	rbd_dev->layout.pool_id = spec->pool_id;
-	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
-
 	return rbd_dev;
 }
 
@@ -5848,12 +5858,13 @@ static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
 			goto out_err;
 	}
 
+	rbd_init_layout(rbd_dev);
 	return 0;
+
 out_err:
 	rbd_dev->header.features = 0;
 	kfree(rbd_dev->header.object_prefix);
 	rbd_dev->header.object_prefix = NULL;
-
 	return ret;
 }
 
-- 
2.4.3

[PATCH 10/15] rbd: support for data-pool feature

[Ilya Dryomov]

Add support for RBD_FEATURE_DATA_POOL feature.  rbd_dev->layout.pool_id
now stores the data pool id.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index aac1d3259738..f01dfdfa5645 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -123,9 +123,11 @@ static int atomic_dec_return_safe(atomic_t *v)
 #define RBD_FEATURE_LAYERING	(1<<0)
 #define RBD_FEATURE_STRIPINGV2	(1<<1)
 #define RBD_FEATURE_EXCLUSIVE_LOCK (1<<2)
+#define RBD_FEATURE_DATA_POOL (1<<7)
 #define RBD_FEATURES_ALL	(RBD_FEATURE_LAYERING |		\
 				 RBD_FEATURE_STRIPINGV2 |	\
-				 RBD_FEATURE_EXCLUSIVE_LOCK)
+				 RBD_FEATURE_EXCLUSIVE_LOCK |	\
+				 RBD_FEATURE_DATA_POOL)
 
 /* Features supported by this (client software) implementation. */
 
@@ -146,6 +148,7 @@ struct rbd_image_header {
 	__u8 obj_order;
 	u64 stripe_unit;
 	u64 stripe_count;
+	s64 data_pool_id;
 	u64 features;		/* Might be changeable someday? */
 
 	/* The remaining fields need to be updated occasionally */
@@ -989,7 +992,8 @@ static void rbd_init_layout(struct rbd_device *rbd_dev)
 	rbd_dev->layout.stripe_unit = rbd_dev->header.stripe_unit;
 	rbd_dev->layout.stripe_count = rbd_dev->header.stripe_count;
 	rbd_dev->layout.object_size = rbd_obj_bytes(&rbd_dev->header);
-	rbd_dev->layout.pool_id = rbd_dev->spec->pool_id;
+	rbd_dev->layout.pool_id = rbd_dev->header.data_pool_id == CEPH_NOPOOL ?
+			  rbd_dev->spec->pool_id : rbd_dev->header.data_pool_id;
 	RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
 }
 
@@ -4797,6 +4801,7 @@ static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
 	INIT_LIST_HEAD(&rbd_dev->node);
 	init_rwsem(&rbd_dev->header_rwsem);
 
+	rbd_dev->header.data_pool_id = CEPH_NOPOOL;
 	ceph_oid_init(&rbd_dev->header_oid);
 	rbd_dev->header_oloc.pool = spec->pool_id;
 
@@ -5161,6 +5166,24 @@ static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
 	return 0;
 }
 
+static int rbd_dev_v2_data_pool(struct rbd_device *rbd_dev)
+{
+	__le64 data_pool_id;
+	int ret;
+
+	ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+				  &rbd_dev->header_oloc, "get_data_pool",
+				  NULL, 0, &data_pool_id, sizeof(data_pool_id));
+	if (ret < 0)
+		return ret;
+	if (ret < sizeof(data_pool_id))
+		return -EBADMSG;
+
+	rbd_dev->header.data_pool_id = le64_to_cpu(data_pool_id);
+	WARN_ON(rbd_dev->header.data_pool_id == CEPH_NOPOOL);
+	return 0;
+}
+
 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
 {
 	CEPH_DEFINE_OID_ONSTACK(oid);
@@ -5858,6 +5881,12 @@ static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
 			goto out_err;
 	}
 
+	if (rbd_dev->header.features & RBD_FEATURE_DATA_POOL) {
+		ret = rbd_dev_v2_data_pool(rbd_dev);
+		if (ret)
+			goto out_err;
+	}
+
 	rbd_init_layout(rbd_dev);
 	return 0;
 
-- 
2.4.3

[PATCH 11/15] rbd: set offset and length outside of rbd_obj_request_create()

[Ilya Dryomov]

The allocation doesn't depend on offset and length.  Both offset and
length can be changed after obj_request is allocated, too.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index f01dfdfa5645..ea60d238ca55 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1631,7 +1631,9 @@ static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
 {
 	struct ceph_osd_request *osd_req = obj_request->osd_req;
 
-	dout("%s %p osd_req %p\n", __func__, obj_request, osd_req);
+	dout("%s %p \"%s\" %llu~%llu osd_req %p\n", __func__,
+	     obj_request, obj_request->object_name, obj_request->offset,
+	     obj_request->length, osd_req);
 	if (obj_request_img_data_test(obj_request)) {
 		WARN_ON(obj_request->callback != rbd_img_obj_callback);
 		rbd_img_request_get(obj_request->img_request);
@@ -2073,7 +2075,6 @@ static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
 /* object_name is assumed to be a non-null pointer and NUL-terminated */
 
 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
-						u64 offset, u64 length,
 						enum obj_request_type type)
 {
 	struct rbd_obj_request *obj_request;
@@ -2094,18 +2095,13 @@ static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
 	}
 
 	obj_request->object_name = memcpy(name, object_name, size);
-	obj_request->offset = offset;
-	obj_request->length = length;
-	obj_request->flags = 0;
 	obj_request->which = BAD_WHICH;
 	obj_request->type = type;
 	INIT_LIST_HEAD(&obj_request->links);
 	init_completion(&obj_request->completion);
 	kref_init(&obj_request->kref);
 
-	dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
-		offset, length, (int)type, obj_request);
-
+	dout("%s %p\n", __func__, obj_request);
 	return obj_request;
 }
 
@@ -2517,21 +2513,21 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
 	while (resid) {
 		struct ceph_osd_request *osd_req;
 		const char *object_name;
-		u64 offset;
-		u64 length;
+		u64 offset = rbd_segment_offset(rbd_dev, img_offset);
+		u64 length = rbd_segment_length(rbd_dev, img_offset, resid);
 
 		object_name = rbd_segment_name(rbd_dev, img_offset);
 		if (!object_name)
 			goto out_unwind;
-		offset = rbd_segment_offset(rbd_dev, img_offset);
-		length = rbd_segment_length(rbd_dev, img_offset, resid);
-		obj_request = rbd_obj_request_create(object_name,
-						offset, length, type);
+		obj_request = rbd_obj_request_create(object_name, type);
 		/* object request has its own copy of the object name */
 		rbd_segment_name_free(object_name);
 		if (!obj_request)
 			goto out_unwind;
 
+		obj_request->offset = offset;
+		obj_request->length = length;
+
 		/*
 		 * set obj_request->img_request before creating the
 		 * osd_request so that it gets the right snapc
@@ -2870,7 +2866,7 @@ static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
 	size_t size;
 	int ret;
 
-	stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
+	stat_request = rbd_obj_request_create(obj_request->object_name,
 					      OBJ_REQUEST_PAGES);
 	if (!stat_request)
 		return -ENOMEM;
-- 
2.4.3

[PATCH 12/15] rbd: factor out __rbd_osd_req_create()

[Ilya Dryomov]

Factor OSD request allocation and initialization code out into
__rbd_osd_req_create().

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 103 ++++++++++++++++++++--------------------------------
 1 file changed, 40 insertions(+), 63 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index ea60d238ca55..47cfd5d89e69 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1952,6 +1952,38 @@ static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
 	osd_req->r_data_offset = obj_request->offset;
 }
 
+static struct ceph_osd_request *
+__rbd_osd_req_create(struct rbd_device *rbd_dev,
+		     struct ceph_snap_context *snapc,
+		     int num_ops, unsigned int flags,
+		     struct rbd_obj_request *obj_request)
+{
+	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+	struct ceph_osd_request *req;
+
+	req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false, GFP_NOIO);
+	if (!req)
+		return NULL;
+
+	req->r_flags = flags;
+	req->r_callback = rbd_osd_req_callback;
+	req->r_priv = obj_request;
+
+	req->r_base_oloc.pool = rbd_dev->layout.pool_id;
+	if (ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, "%s",
+			     obj_request->object_name))
+		goto err_req;
+
+	if (ceph_osdc_alloc_messages(req, GFP_NOIO))
+		goto err_req;
+
+	return req;
+
+err_req:
+	ceph_osdc_put_request(req);
+	return NULL;
+}
+
 /*
  * Create an osd request.  A read request has one osd op (read).
  * A write request has either one (watch) or two (hint+write) osd ops.
@@ -1965,8 +1997,6 @@ static struct ceph_osd_request *rbd_osd_req_create(
 					struct rbd_obj_request *obj_request)
 {
 	struct ceph_snap_context *snapc = NULL;
-	struct ceph_osd_client *osdc;
-	struct ceph_osd_request *osd_req;
 
 	if (obj_request_img_data_test(obj_request) &&
 		(op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
@@ -1981,35 +2011,10 @@ static struct ceph_osd_request *rbd_osd_req_create(
 
 	rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
 
-	/* Allocate and initialize the request, for the num_ops ops */
-
-	osdc = &rbd_dev->rbd_client->client->osdc;
-	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
-					  GFP_NOIO);
-	if (!osd_req)
-		goto fail;
-
-	if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
-		osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
-	else
-		osd_req->r_flags = CEPH_OSD_FLAG_READ;
-
-	osd_req->r_callback = rbd_osd_req_callback;
-	osd_req->r_priv = obj_request;
-
-	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
-	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
-			     obj_request->object_name))
-		goto fail;
-
-	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
-		goto fail;
-
-	return osd_req;
-
-fail:
-	ceph_osdc_put_request(osd_req);
-	return NULL;
+	return __rbd_osd_req_create(rbd_dev, snapc, num_ops,
+	    (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD) ?
+	    CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK : CEPH_OSD_FLAG_READ,
+	    obj_request);
 }
 
 /*
@@ -2022,10 +2027,6 @@ static struct ceph_osd_request *
 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
 {
 	struct rbd_img_request *img_request;
-	struct ceph_snap_context *snapc;
-	struct rbd_device *rbd_dev;
-	struct ceph_osd_client *osdc;
-	struct ceph_osd_request *osd_req;
 	int num_osd_ops = 3;
 
 	rbd_assert(obj_request_img_data_test(obj_request));
@@ -2037,36 +2038,12 @@ rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
 	if (img_request_discard_test(img_request))
 		num_osd_ops = 2;
 
-	/* Allocate and initialize the request, for all the ops */
-
-	snapc = img_request->snapc;
-	rbd_dev = img_request->rbd_dev;
-	osdc = &rbd_dev->rbd_client->client->osdc;
-	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
-						false, GFP_NOIO);
-	if (!osd_req)
-		goto fail;
-
-	osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
-	osd_req->r_callback = rbd_osd_req_callback;
-	osd_req->r_priv = obj_request;
-
-	osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
-	if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
-			     obj_request->object_name))
-		goto fail;
-
-	if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
-		goto fail;
-
-	return osd_req;
-
-fail:
-	ceph_osdc_put_request(osd_req);
-	return NULL;
+	return __rbd_osd_req_create(img_request->rbd_dev,
+				    img_request->snapc, num_osd_ops,
+				    CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
+				    obj_request);
 }
 
-
 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
 {
 	ceph_osdc_put_request(osd_req);
-- 
2.4.3

[PATCH 13/15] rbd: RBD_V{1,2}_DATA_FORMAT macros

[Ilya Dryomov]

... and also fix up the comment -- format 1 data objects have always
been 12 hex digits long.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c       | 6 ++----
 drivers/block/rbd_types.h | 7 ++++---
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 47cfd5d89e69..3bc84afe5b50 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1257,18 +1257,16 @@ static void rbd_segment_name_free(const char *name)
 
 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
 {
+	const char *name_format = rbd_dev->image_format == 1 ?
+				      RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
 	char *name;
 	u64 segment;
 	int ret;
-	char *name_format;
 
 	name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
 	if (!name)
 		return NULL;
 	segment = offset >> rbd_dev->header.obj_order;
-	name_format = "%s.%012llx";
-	if (rbd_dev->image_format == 2)
-		name_format = "%s.%016llx";
 	ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
 			rbd_dev->header.object_prefix, segment);
 	if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
diff --git a/drivers/block/rbd_types.h b/drivers/block/rbd_types.h
index be9c76d292f5..0a15ca3aa0f1 100644
--- a/drivers/block/rbd_types.h
+++ b/drivers/block/rbd_types.h
@@ -25,8 +25,8 @@
  */
 
 #define RBD_HEADER_PREFIX      "rbd_header."
-#define RBD_DATA_PREFIX        "rbd_data."
 #define RBD_ID_PREFIX          "rbd_id."
+#define RBD_V2_DATA_FORMAT     "%s.%016llx"
 
 #define RBD_LOCK_NAME          "rbd_lock"
 #define RBD_LOCK_TAG           "internal"
@@ -42,13 +42,14 @@ enum rbd_notify_op {
 /*
  * For format version 1, rbd image 'foo' consists of objects
  *   foo.rbd		- image metadata
- *   rb.<idhi>.<idlo>.00000000
- *   rb.<idhi>.<idlo>.00000001
+ *   rb.<idhi>.<idlo>.000000000000
+ *   rb.<idhi>.<idlo>.000000000001
  *   ...		- data
  * There is no notion of a persistent image id in rbd format 1.
  */
 
 #define RBD_SUFFIX		".rbd"
+#define RBD_V1_DATA_FORMAT	"%s.%012llx"
 
 #define RBD_DIRECTORY           "rbd_directory"
 #define RBD_INFO                "rbd_info"
-- 
2.4.3

[PATCH 14/15] rbd: store and use obj_request->object_no

[Ilya Dryomov]

object_no can be trivially formatted into an object name.  We already
store object names in OSD requests with special care to avoid dynamic
allocations for short names.  Storing a name in obj_request, obtained
as below (!), is a waste and will be removed in the next commit.

    name = kmem_cache_alloc(rbd_segment_name_cache, ...);
    snprintf(name, ...);
    obj_request->object_name = kstrdup(name);
    kmem_cache_free(rbd_segment_name_cache, name);
    ...
    ceph_oid_aprintf(..., "%s", obj_request->object_name);

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 3bc84afe5b50..3133bb66ce18 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -232,6 +232,7 @@ enum obj_req_flags {
 
 struct rbd_obj_request {
 	const char		*object_name;
+	u64			object_no;
 	u64			offset;		/* object start byte */
 	u64			length;		/* bytes from offset */
 	unsigned long		flags;
@@ -1629,8 +1630,8 @@ static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
 {
 	struct ceph_osd_request *osd_req = obj_request->osd_req;
 
-	dout("%s %p \"%s\" %llu~%llu osd_req %p\n", __func__,
-	     obj_request, obj_request->object_name, obj_request->offset,
+	dout("%s %p object_no %016llx %llu~%llu osd_req %p\n", __func__,
+	     obj_request, obj_request->object_no, obj_request->offset,
 	     obj_request->length, osd_req);
 	if (obj_request_img_data_test(obj_request)) {
 		WARN_ON(obj_request->callback != rbd_img_obj_callback);
@@ -1925,8 +1926,8 @@ static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
 		rbd_osd_call_callback(obj_request);
 		break;
 	default:
-		rbd_warn(NULL, "%s: unsupported op %hu",
-			obj_request->object_name, (unsigned short) opcode);
+		rbd_warn(NULL, "unexpected OSD op: object_no %016llx opcode %d",
+			 obj_request->object_no, opcode);
 		break;
 	}
 
@@ -1958,6 +1959,8 @@ __rbd_osd_req_create(struct rbd_device *rbd_dev,
 {
 	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
 	struct ceph_osd_request *req;
+	const char *name_format = rbd_dev->image_format == 1 ?
+				      RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
 
 	req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false, GFP_NOIO);
 	if (!req)
@@ -1968,8 +1971,8 @@ __rbd_osd_req_create(struct rbd_device *rbd_dev,
 	req->r_priv = obj_request;
 
 	req->r_base_oloc.pool = rbd_dev->layout.pool_id;
-	if (ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, "%s",
-			     obj_request->object_name))
+	if (ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, name_format,
+			rbd_dev->header.object_prefix, obj_request->object_no))
 		goto err_req;
 
 	if (ceph_osdc_alloc_messages(req, GFP_NOIO))
@@ -2488,6 +2491,7 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
 	while (resid) {
 		struct ceph_osd_request *osd_req;
 		const char *object_name;
+		u64 object_no = img_offset >> rbd_dev->header.obj_order;
 		u64 offset = rbd_segment_offset(rbd_dev, img_offset);
 		u64 length = rbd_segment_length(rbd_dev, img_offset, resid);
 
@@ -2500,6 +2504,7 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
 		if (!obj_request)
 			goto out_unwind;
 
+		obj_request->object_no = object_no;
 		obj_request->offset = offset;
 		obj_request->length = length;
 
@@ -2846,6 +2851,8 @@ static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
 	if (!stat_request)
 		return -ENOMEM;
 
+	stat_request->object_no = obj_request->object_no;
+
 	stat_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
 						   stat_request);
 	if (!stat_request->osd_req) {
-- 
2.4.3

[PATCH 15/15] rbd: kill obj_request->object_name and rbd_segment_name_cache

[Ilya Dryomov]

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c         | 79 ++++-----------------------------------------
 include/linux/ceph/osdmap.h |  7 ----
 2 files changed, 7 insertions(+), 79 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 3133bb66ce18..24e05b02d033 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -231,7 +231,6 @@ enum obj_req_flags {
 };
 
 struct rbd_obj_request {
-	const char		*object_name;
 	u64			object_no;
 	u64			offset;		/* object start byte */
 	u64			length;		/* bytes from offset */
@@ -440,7 +439,6 @@ static DEFINE_SPINLOCK(rbd_client_list_lock);
 
 static struct kmem_cache	*rbd_img_request_cache;
 static struct kmem_cache	*rbd_obj_request_cache;
-static struct kmem_cache	*rbd_segment_name_cache;
 
 static int rbd_major;
 static DEFINE_IDA(rbd_dev_id_ida);
@@ -1249,37 +1247,6 @@ static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
 	rbd_dev->mapping.features = 0;
 }
 
-static void rbd_segment_name_free(const char *name)
-{
-	/* The explicit cast here is needed to drop the const qualifier */
-
-	kmem_cache_free(rbd_segment_name_cache, (void *)name);
-}
-
-static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
-{
-	const char *name_format = rbd_dev->image_format == 1 ?
-				      RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
-	char *name;
-	u64 segment;
-	int ret;
-
-	name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
-	if (!name)
-		return NULL;
-	segment = offset >> rbd_dev->header.obj_order;
-	ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
-			rbd_dev->header.object_prefix, segment);
-	if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
-		pr_err("error formatting segment name for #%llu (%d)\n",
-			segment, ret);
-		rbd_segment_name_free(name);
-		name = NULL;
-	}
-
-	return name;
-}
-
 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
 {
 	u64 segment_size = rbd_obj_bytes(&rbd_dev->header);
@@ -2050,29 +2017,17 @@ static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
 	ceph_osdc_put_request(osd_req);
 }
 
-/* object_name is assumed to be a non-null pointer and NUL-terminated */
-
-static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
-						enum obj_request_type type)
+static struct rbd_obj_request *
+rbd_obj_request_create(enum obj_request_type type)
 {
 	struct rbd_obj_request *obj_request;
-	size_t size;
-	char *name;
 
 	rbd_assert(obj_request_type_valid(type));
 
-	size = strlen(object_name) + 1;
-	name = kmalloc(size, GFP_NOIO);
-	if (!name)
-		return NULL;
-
 	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
-	if (!obj_request) {
-		kfree(name);
+	if (!obj_request)
 		return NULL;
-	}
 
-	obj_request->object_name = memcpy(name, object_name, size);
 	obj_request->which = BAD_WHICH;
 	obj_request->type = type;
 	INIT_LIST_HEAD(&obj_request->links);
@@ -2114,8 +2069,6 @@ static void rbd_obj_request_destroy(struct kref *kref)
 		break;
 	}
 
-	kfree(obj_request->object_name);
-	obj_request->object_name = NULL;
 	kmem_cache_free(rbd_obj_request_cache, obj_request);
 }
 
@@ -2490,17 +2443,11 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
 
 	while (resid) {
 		struct ceph_osd_request *osd_req;
-		const char *object_name;
 		u64 object_no = img_offset >> rbd_dev->header.obj_order;
 		u64 offset = rbd_segment_offset(rbd_dev, img_offset);
 		u64 length = rbd_segment_length(rbd_dev, img_offset, resid);
 
-		object_name = rbd_segment_name(rbd_dev, img_offset);
-		if (!object_name)
-			goto out_unwind;
-		obj_request = rbd_obj_request_create(object_name, type);
-		/* object request has its own copy of the object name */
-		rbd_segment_name_free(object_name);
+		obj_request = rbd_obj_request_create(type);
 		if (!obj_request)
 			goto out_unwind;
 
@@ -2846,8 +2793,7 @@ static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
 	size_t size;
 	int ret;
 
-	stat_request = rbd_obj_request_create(obj_request->object_name,
-					      OBJ_REQUEST_PAGES);
+	stat_request = rbd_obj_request_create(OBJ_REQUEST_PAGES);
 	if (!stat_request)
 		return -ENOMEM;
 
@@ -6389,27 +6335,16 @@ static int rbd_slab_init(void)
 	if (!rbd_obj_request_cache)
 		goto out_err;
 
-	rbd_assert(!rbd_segment_name_cache);
-	rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
-					CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
-	if (rbd_segment_name_cache)
-		return 0;
-out_err:
-	kmem_cache_destroy(rbd_obj_request_cache);
-	rbd_obj_request_cache = NULL;
+	return 0;
 
+out_err:
 	kmem_cache_destroy(rbd_img_request_cache);
 	rbd_img_request_cache = NULL;
-
 	return -ENOMEM;
 }
 
 static void rbd_slab_exit(void)
 {
-	rbd_assert(rbd_segment_name_cache);
-	kmem_cache_destroy(rbd_segment_name_cache);
-	rbd_segment_name_cache = NULL;
-
 	rbd_assert(rbd_obj_request_cache);
 	kmem_cache_destroy(rbd_obj_request_cache);
 	rbd_obj_request_cache = NULL;
diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h
index 8cebdc4158c3..938656f70807 100644
--- a/include/linux/ceph/osdmap.h
+++ b/include/linux/ceph/osdmap.h
@@ -82,13 +82,6 @@ void ceph_oloc_copy(struct ceph_object_locator *dest,
 void ceph_oloc_destroy(struct ceph_object_locator *oloc);
 
 /*
- * Maximum supported by kernel client object name length
- *
- * (probably outdated: must be >= RBD_MAX_MD_NAME_LEN -- currently 100)
- */
-#define CEPH_MAX_OID_NAME_LEN 100
-
-/*
  * 51-char inline_name is long enough for all cephfs and all but one
  * rbd requests: <imgname> in "<imgname>.rbd"/"rbd_id.<imgname>" can be
  * arbitrarily long (~PAGE_SIZE).  It's done once during rbd map; all
-- 
2.4.3

Re: [PATCH 13/15] rbd: RBD_V{1,2}_DATA_FORMAT macros

[Jason Dillaman]

Nit: only since you are correcting the v1 name format, it should also
include 32bits of "extra" randomness (i.e.
rb.<idhi>.<idlo>.<extra>.000000000000). Looks like it's documented
incorrectly in librbd as well.

On Tue, Feb 14, 2017 at 3:12 PM, Ilya Dryomov <idryomov@gmail.com> wrote:
> ... and also fix up the comment -- format 1 data objects have always
> been 12 hex digits long.
>
> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
> ---
>  drivers/block/rbd.c       | 6 ++----
>  drivers/block/rbd_types.h | 7 ++++---
>  2 files changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 47cfd5d89e69..3bc84afe5b50 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -1257,18 +1257,16 @@ static void rbd_segment_name_free(const char *name)
>
>  static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
>  {
> +       const char *name_format = rbd_dev->image_format == 1 ?
> +                                     RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
>         char *name;
>         u64 segment;
>         int ret;
> -       char *name_format;
>
>         name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
>         if (!name)
>                 return NULL;
>         segment = offset >> rbd_dev->header.obj_order;
> -       name_format = "%s.%012llx";
> -       if (rbd_dev->image_format == 2)
> -               name_format = "%s.%016llx";
>         ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
>                         rbd_dev->header.object_prefix, segment);
>         if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
> diff --git a/drivers/block/rbd_types.h b/drivers/block/rbd_types.h
> index be9c76d292f5..0a15ca3aa0f1 100644
> --- a/drivers/block/rbd_types.h
> +++ b/drivers/block/rbd_types.h
> @@ -25,8 +25,8 @@
>   */
>
>  #define RBD_HEADER_PREFIX      "rbd_header."
> -#define RBD_DATA_PREFIX        "rbd_data."
>  #define RBD_ID_PREFIX          "rbd_id."
> +#define RBD_V2_DATA_FORMAT     "%s.%016llx"
>
>  #define RBD_LOCK_NAME          "rbd_lock"
>  #define RBD_LOCK_TAG           "internal"
> @@ -42,13 +42,14 @@ enum rbd_notify_op {
>  /*
>   * For format version 1, rbd image 'foo' consists of objects
>   *   foo.rbd           - image metadata
> - *   rb.<idhi>.<idlo>.00000000
> - *   rb.<idhi>.<idlo>.00000001
> + *   rb.<idhi>.<idlo>.000000000000
> + *   rb.<idhi>.<idlo>.000000000001
>   *   ...               - data
>   * There is no notion of a persistent image id in rbd format 1.
>   */
>
>  #define RBD_SUFFIX             ".rbd"
> +#define RBD_V1_DATA_FORMAT     "%s.%012llx"
>
>  #define RBD_DIRECTORY           "rbd_directory"
>  #define RBD_INFO                "rbd_info"
> --
> 2.4.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Jason

Re: [PATCH 00/15] rbd: support for data-pool + obj_request->object_no

[Jason Dillaman]

Reviewed-by: Jason Dillaman <dillaman@redhat.com>

On Tue, Feb 14, 2017 at 3:11 PM, Ilya Dryomov <idryomov@gmail.com> wrote:
> Hello,
>
> There are two pieces here: support for RBD_FEATURE_DATA_POOL (patches
> 1-10) and a couple of cleanups / minor optimizations that build on it
> and allow us to get rid of rbd_segment_name_cache (patches 11 - 15).
>
> Thanks,
>
>                 Ilya
>
>
> Ilya Dryomov (15):
>   rbd: use kstrndup() in rbd_header_from_disk()
>   rbd: kill rbd_image_header::{crypt_type,comp_type}
>   rbd: initialize rbd_dev->header_oloc early
>   rbd: do away with obj_request in rbd_obj_read_sync()
>   libceph: pass reply buffer length through ceph_osdc_call()
>   rbd: switch rbd_obj_method_sync() to ceph_osdc_call()
>   rbd: remove now unused rbd_obj_request_wait() and helpers
>   rbd: use rbd_obj_bytes() more
>   rbd: introduce rbd_init_layout()
>   rbd: support for data-pool feature
>   rbd: set offset and length outside of rbd_obj_request_create()
>   rbd: factor out __rbd_osd_req_create()
>   rbd: RBD_V{1,2}_DATA_FORMAT macros
>   rbd: store and use obj_request->object_no
>   rbd: kill obj_request->object_name and rbd_segment_name_cache
>
>  drivers/block/rbd.c         | 601 +++++++++++++++++---------------------------
>  drivers/block/rbd_types.h   |  10 +-
>  include/linux/ceph/osdmap.h |   7 -
>  net/ceph/cls_lock_client.c  |   2 +-
>  net/ceph/osd_client.c       |   7 +-
>  5 files changed, 238 insertions(+), 389 deletions(-)
>
> --
> 2.4.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
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-- 
Jason

Re: [PATCH 01/15] rbd: use kstrndup() in rbd_header_from_disk()

[Alex Elder]

On 02/14/2017 02:11 PM, Ilya Dryomov wrote:
> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Looks good.

Reviewed-by: Alex Elder <elder@linaro.org>


> ---
>  drivers/block/rbd.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 40a15ae354ce..76e538c3378e 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -992,15 +992,11 @@ static int rbd_header_from_disk(struct rbd_device *rbd_dev,
>  	/* Allocate this now to avoid having to handle failure below */
>  
>  	if (first_time) {
> -		size_t len;
> -
> -		len = strnlen(ondisk->object_prefix,
> -				sizeof (ondisk->object_prefix));
> -		object_prefix = kmalloc(len + 1, GFP_KERNEL);
> +		object_prefix = kstrndup(ondisk->object_prefix,
> +					 sizeof(ondisk->object_prefix),
> +					 GFP_KERNEL);
>  		if (!object_prefix)
>  			return -ENOMEM;
> -		memcpy(object_prefix, ondisk->object_prefix, len);
> -		object_prefix[len] = '\0';
>  	}
>  
>  	/* Allocate the snapshot context and fill it in */
> 

Re: [PATCH 01/15] rbd: use kstrndup() in rbd_header_from_disk()

[Alex Elder]

On 02/14/2017 02:11 PM, Ilya Dryomov wrote:
> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Looks good.

Reviewed-by: Alex Elder <elder@linaro.org>


> ---
>  drivers/block/rbd.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 40a15ae354ce..76e538c3378e 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -992,15 +992,11 @@ static int rbd_header_from_disk(struct rbd_device *rbd_dev,
>  	/* Allocate this now to avoid having to handle failure below */
>  
>  	if (first_time) {
> -		size_t len;
> -
> -		len = strnlen(ondisk->object_prefix,
> -				sizeof (ondisk->object_prefix));
> -		object_prefix = kmalloc(len + 1, GFP_KERNEL);
> +		object_prefix = kstrndup(ondisk->object_prefix,
> +					 sizeof(ondisk->object_prefix),
> +					 GFP_KERNEL);
>  		if (!object_prefix)
>  			return -ENOMEM;
> -		memcpy(object_prefix, ondisk->object_prefix, len);
> -		object_prefix[len] = '\0';
>  	}
>  
>  	/* Allocate the snapshot context and fill it in */
>