obj_req->xferred and img_req->xferred don't bring any value. The
former is used for short reads and has to be set to obj_req->ex.oe_len
after that and elsewhere. The latter is just an aggregate.
Use result for short reads (>=0 - number of bytes read, <0 - error) and
pass it around explicitly. No need to store it in obj_req.
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
---
drivers/block/rbd.c | 149 +++++++++++++++++---------------------------
1 file changed, 58 insertions(+), 91 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index e5009a34f9c2..a9b0b23148f9 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -276,9 +276,6 @@ struct rbd_obj_request {
struct ceph_osd_request *osd_req;
- u64 xferred; /* bytes transferred */
- int result;
-
struct kref kref;
};
@@ -301,7 +298,6 @@ struct rbd_img_request {
struct rbd_obj_request *obj_request; /* obj req initiator */
};
spinlock_t completion_lock;
- u64 xferred;/* aggregate bytes transferred */
int result; /* first nonzero obj_request result */
struct list_head object_extents; /* obj_req.ex structs */
@@ -584,6 +580,8 @@ static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
u64 *snap_features);
+static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result);
+
static int rbd_open(struct block_device *bdev, fmode_t mode)
{
struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
@@ -1317,6 +1315,8 @@ static void zero_bvecs(struct ceph_bvec_iter *bvec_pos, u32 off, u32 bytes)
static void rbd_obj_zero_range(struct rbd_obj_request *obj_req, u32 off,
u32 bytes)
{
+ dout("%s %p data buf %u~%u\n", __func__, obj_req, off, bytes);
+
switch (obj_req->img_request->data_type) {
case OBJ_REQUEST_BIO:
zero_bios(&obj_req->bio_pos, off, bytes);
@@ -1457,28 +1457,26 @@ static bool rbd_img_is_write(struct rbd_img_request *img_req)
}
}
-static void rbd_obj_handle_request(struct rbd_obj_request *obj_req);
-
static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
{
struct rbd_obj_request *obj_req = osd_req->r_priv;
+ int result;
dout("%s osd_req %p result %d for obj_req %p\n", __func__, osd_req,
osd_req->r_result, obj_req);
rbd_assert(osd_req == obj_req->osd_req);
- obj_req->result = osd_req->r_result < 0 ? osd_req->r_result : 0;
- if (!obj_req->result && !rbd_img_is_write(obj_req->img_request))
- obj_req->xferred = osd_req->r_result;
+ /*
+ * Writes aren't allowed to return a data payload. In some
+ * guarded write cases (e.g. stat + zero on an empty object)
+ * a stat response makes it through, but we don't care.
+ */
+ if (osd_req->r_result > 0 && rbd_img_is_write(obj_req->img_request))
+ result = 0;
else
- /*
- * Writes aren't allowed to return a data payload. In some
- * guarded write cases (e.g. stat + zero on an empty object)
- * a stat response makes it through, but we don't care.
- */
- obj_req->xferred = 0;
+ result = osd_req->r_result;
- rbd_obj_handle_request(obj_req);
+ rbd_obj_handle_request(obj_req, result);
}
static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
@@ -2041,7 +2039,6 @@ static int __rbd_img_fill_request(struct rbd_img_request *img_req)
if (ret < 0)
return ret;
if (ret > 0) {
- img_req->xferred += obj_req->ex.oe_len;
img_req->pending_count--;
rbd_img_obj_request_del(img_req, obj_req);
continue;
@@ -2400,17 +2397,17 @@ static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
return 0;
}
-static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req)
+static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req, int *result)
{
struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
int ret;
- if (obj_req->result == -ENOENT &&
+ if (*result == -ENOENT &&
rbd_dev->parent_overlap && !obj_req->tried_parent) {
/* reverse map this object extent onto the parent */
ret = rbd_obj_calc_img_extents(obj_req, false);
if (ret) {
- obj_req->result = ret;
+ *result = ret;
return true;
}
@@ -2418,7 +2415,7 @@ static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req)
obj_req->tried_parent = true;
ret = rbd_obj_read_from_parent(obj_req);
if (ret) {
- obj_req->result = ret;
+ *result = ret;
return true;
}
return false;
@@ -2428,16 +2425,18 @@ static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req)
/*
* -ENOENT means a hole in the image -- zero-fill the entire
* length of the request. A short read also implies zero-fill
- * to the end of the request. In both cases we update xferred
- * count to indicate the whole request was satisfied.
+ * to the end of the request.
*/
- if (obj_req->result == -ENOENT ||
- (!obj_req->result && obj_req->xferred < obj_req->ex.oe_len)) {
- rbd_assert(!obj_req->xferred || !obj_req->result);
- rbd_obj_zero_range(obj_req, obj_req->xferred,
- obj_req->ex.oe_len - obj_req->xferred);
- obj_req->result = 0;
- obj_req->xferred = obj_req->ex.oe_len;
+ if (*result == -ENOENT) {
+ rbd_obj_zero_range(obj_req, 0, obj_req->ex.oe_len);
+ *result = 0;
+ } else if (*result >= 0) {
+ if (*result < obj_req->ex.oe_len)
+ rbd_obj_zero_range(obj_req, *result,
+ obj_req->ex.oe_len - *result);
+ else
+ rbd_assert(*result == obj_req->ex.oe_len);
+ *result = 0;
}
return true;
@@ -2635,14 +2634,13 @@ static int rbd_obj_handle_write_guard(struct rbd_obj_request *obj_req)
return rbd_obj_read_from_parent(obj_req);
}
-static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req)
+static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req, int *result)
{
int ret;
switch (obj_req->write_state) {
case RBD_OBJ_WRITE_GUARD:
- rbd_assert(!obj_req->xferred);
- if (obj_req->result == -ENOENT) {
+ if (*result == -ENOENT) {
/*
* The target object doesn't exist. Read the data for
* the entire target object up to the overlap point (if
@@ -2650,7 +2648,7 @@ static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req)
*/
ret = rbd_obj_handle_write_guard(obj_req);
if (ret) {
- obj_req->result = ret;
+ *result = ret;
return true;
}
return false;
@@ -2658,33 +2656,26 @@ static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req)
/* fall through */
case RBD_OBJ_WRITE_FLAT:
case RBD_OBJ_WRITE_COPYUP_OPS:
- if (!obj_req->result)
- /*
- * There is no such thing as a successful short
- * write -- indicate the whole request was satisfied.
- */
- obj_req->xferred = obj_req->ex.oe_len;
return true;
case RBD_OBJ_WRITE_READ_FROM_PARENT:
- if (obj_req->result)
+ if (*result < 0)
return true;
- rbd_assert(obj_req->xferred);
- ret = rbd_obj_issue_copyup(obj_req, obj_req->xferred);
+ rbd_assert(*result);
+ ret = rbd_obj_issue_copyup(obj_req, *result);
if (ret) {
- obj_req->result = ret;
- obj_req->xferred = 0;
+ *result = ret;
return true;
}
return false;
case RBD_OBJ_WRITE_COPYUP_EMPTY_SNAPC:
- if (obj_req->result)
+ if (*result)
return true;
obj_req->write_state = RBD_OBJ_WRITE_COPYUP_OPS;
ret = rbd_obj_issue_copyup_ops(obj_req, MODS_ONLY);
if (ret) {
- obj_req->result = ret;
+ *result = ret;
return true;
}
return false;
@@ -2696,24 +2687,23 @@ static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req)
/*
* Returns true if @obj_req is completed, or false otherwise.
*/
-static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req)
+static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req,
+ int *result)
{
switch (obj_req->img_request->op_type) {
case OBJ_OP_READ:
- return rbd_obj_handle_read(obj_req);
+ return rbd_obj_handle_read(obj_req, result);
case OBJ_OP_WRITE:
- return rbd_obj_handle_write(obj_req);
+ return rbd_obj_handle_write(obj_req, result);
case OBJ_OP_DISCARD:
case OBJ_OP_ZEROOUT:
- if (rbd_obj_handle_write(obj_req)) {
+ if (rbd_obj_handle_write(obj_req, result)) {
/*
* Hide -ENOENT from delete/truncate/zero -- discarding
* a non-existent object is not a problem.
*/
- if (obj_req->result == -ENOENT) {
- obj_req->result = 0;
- obj_req->xferred = obj_req->ex.oe_len;
- }
+ if (*result == -ENOENT)
+ *result = 0;
return true;
}
return false;
@@ -2722,66 +2712,41 @@ static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req)
}
}
-static void rbd_obj_end_request(struct rbd_obj_request *obj_req)
+static void rbd_obj_end_request(struct rbd_obj_request *obj_req, int result)
{
struct rbd_img_request *img_req = obj_req->img_request;
- rbd_assert((!obj_req->result &&
- obj_req->xferred == obj_req->ex.oe_len) ||
- (obj_req->result < 0 && !obj_req->xferred));
- if (!obj_req->result) {
- img_req->xferred += obj_req->xferred;
+ rbd_assert(result <= 0);
+ if (!result)
return;
- }
- rbd_warn(img_req->rbd_dev,
- "%s at objno %llu %llu~%llu result %d xferred %llu",
+ rbd_warn(img_req->rbd_dev, "%s at objno %llu %llu~%llu result %d",
obj_op_name(img_req->op_type), obj_req->ex.oe_objno,
- obj_req->ex.oe_off, obj_req->ex.oe_len, obj_req->result,
- obj_req->xferred);
- if (!img_req->result) {
- img_req->result = obj_req->result;
- img_req->xferred = 0;
- }
-}
-
-static void rbd_img_end_child_request(struct rbd_img_request *img_req)
-{
- struct rbd_obj_request *obj_req = img_req->obj_request;
-
- rbd_assert(test_bit(IMG_REQ_CHILD, &img_req->flags));
- rbd_assert((!img_req->result &&
- img_req->xferred == rbd_obj_img_extents_bytes(obj_req)) ||
- (img_req->result < 0 && !img_req->xferred));
-
- obj_req->result = img_req->result;
- obj_req->xferred = img_req->xferred;
- rbd_img_request_put(img_req);
+ obj_req->ex.oe_off, obj_req->ex.oe_len, result);
+ if (!img_req->result)
+ img_req->result = result;
}
static void rbd_img_end_request(struct rbd_img_request *img_req)
{
rbd_assert(!test_bit(IMG_REQ_CHILD, &img_req->flags));
- rbd_assert((!img_req->result &&
- img_req->xferred == blk_rq_bytes(img_req->rq)) ||
- (img_req->result < 0 && !img_req->xferred));
blk_mq_end_request(img_req->rq,
errno_to_blk_status(img_req->result));
rbd_img_request_put(img_req);
}
-static void rbd_obj_handle_request(struct rbd_obj_request *obj_req)
+static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result)
{
struct rbd_img_request *img_req;
again:
- if (!__rbd_obj_handle_request(obj_req))
+ if (!__rbd_obj_handle_request(obj_req, &result))
return;
img_req = obj_req->img_request;
spin_lock(&img_req->completion_lock);
- rbd_obj_end_request(obj_req);
+ rbd_obj_end_request(obj_req, result);
rbd_assert(img_req->pending_count);
if (--img_req->pending_count) {
spin_unlock(&img_req->completion_lock);
@@ -2789,9 +2754,11 @@ static void rbd_obj_handle_request(struct rbd_obj_request *obj_req)
}
spin_unlock(&img_req->completion_lock);
+ rbd_assert(img_req->result <= 0);
if (test_bit(IMG_REQ_CHILD, &img_req->flags)) {
obj_req = img_req->obj_request;
- rbd_img_end_child_request(img_req);
+ result = img_req->result ?: rbd_obj_img_extents_bytes(obj_req);
+ rbd_img_request_put(img_req);
goto again;
}
rbd_img_end_request(img_req);
--
2.19.2
