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Commit 86bd7998 authored by Ilya Dryomov's avatar Ilya Dryomov
Browse files

rbd: move to obj_req->img_extents 



In preparation for rbd "fancy" striping, replace obj_req->img_offset
with obj_req->img_extents.  A single starting offset isn't sufficient
because we want only one OSD request per object and will merge adjacent
object extents in ceph_file_to_extents().  The final object extent may
map into multiple different byte ranges in the image.

Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 43df3d35

drivers/block/rbd.c

+98 −52
Original line number Diff line number Diff line
@@ -253,7 +253,8 @@ struct rbd_obj_request { 
	};



	struct rbd_img_request	*img_request;

	u64			img_offset;

	struct ceph_file_extent	*img_extents;

	u32			num_img_extents;



	union {

		struct ceph_bio_iter	bio_pos;
@@ -1279,14 +1280,6 @@ static void rbd_obj_zero_range(struct rbd_obj_request *obj_req, u32 off, 
	}

}



static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)

{

	struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;



	return obj_request->img_offset <

	    round_up(rbd_dev->parent_overlap, rbd_obj_bytes(&rbd_dev->header));

}



static void rbd_obj_request_get(struct rbd_obj_request *obj_request)

{

	dout("%s: obj %p (was %d)\n", __func__, obj_request,
@@ -1415,6 +1408,12 @@ static bool rbd_obj_is_tail(struct rbd_obj_request *obj_req) 
					rbd_dev->layout.object_size;

}



static u64 rbd_obj_img_extents_bytes(struct rbd_obj_request *obj_req)

{

	return ceph_file_extents_bytes(obj_req->img_extents,

				       obj_req->num_img_extents);

}



static bool rbd_img_is_write(struct rbd_img_request *img_req)

{

	switch (img_req->op_type) {
@@ -1544,6 +1543,7 @@ static void rbd_obj_request_destroy(struct kref *kref) 
		rbd_assert(0);

	}



	kfree(obj_request->img_extents);

	if (obj_request->copyup_bvecs) {

		for (i = 0; i < obj_request->copyup_bvec_count; i++) {

			if (obj_request->copyup_bvecs[i].bv_page)
@@ -1718,6 +1718,53 @@ static void rbd_parent_request_destroy(struct kref *kref) 
	rbd_img_request_destroy(kref);

}



static void prune_extents(struct ceph_file_extent *img_extents,

			  u32 *num_img_extents, u64 overlap)

{

	u32 cnt = *num_img_extents;



	/* drop extents completely beyond the overlap */

	while (cnt && img_extents[cnt - 1].fe_off >= overlap)

		cnt--;



	if (cnt) {

		struct ceph_file_extent *ex = &img_extents[cnt - 1];



		/* trim final overlapping extent */

		if (ex->fe_off + ex->fe_len > overlap)

			ex->fe_len = overlap - ex->fe_off;

	}



	*num_img_extents = cnt;

}



/*

 * Determine the byte range(s) covered by either just the object extent

 * or the entire object in the parent image.

 */

static int rbd_obj_calc_img_extents(struct rbd_obj_request *obj_req,

				    bool entire)

{

	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;

	int ret;



	if (!rbd_dev->parent_overlap)

		return 0;



	ret = ceph_extent_to_file(&rbd_dev->layout, obj_req->ex.oe_objno,

				  entire ? 0 : obj_req->ex.oe_off,

				  entire ? rbd_dev->layout.object_size :

							obj_req->ex.oe_len,

				  &obj_req->img_extents,

				  &obj_req->num_img_extents);

	if (ret)

		return ret;



	prune_extents(obj_req->img_extents, &obj_req->num_img_extents,

		      rbd_dev->parent_overlap);

	return 0;

}



static void rbd_osd_req_setup_data(struct rbd_obj_request *obj_req, u32 which)

{

	switch (obj_req->img_request->data_type) {
@@ -1803,7 +1850,12 @@ static int rbd_obj_setup_write(struct rbd_obj_request *obj_req) 
	unsigned int num_osd_ops, which = 0;

	int ret;



	if (obj_request_overlaps_parent(obj_req)) {

	/* reverse map the entire object onto the parent */

	ret = rbd_obj_calc_img_extents(obj_req, true);

	if (ret)

		return ret;



	if (obj_req->num_img_extents) {

		obj_req->write_state = RBD_OBJ_WRITE_GUARD;

		num_osd_ops = 3; /* stat + setallochint + write/writefull */

	} else {
@@ -1815,7 +1867,7 @@ static int rbd_obj_setup_write(struct rbd_obj_request *obj_req) 
	if (!obj_req->osd_req)

		return -ENOMEM;



	if (obj_request_overlaps_parent(obj_req)) {

	if (obj_req->num_img_extents) {

		ret = __rbd_obj_setup_stat(obj_req, which++);

		if (ret)

			return ret;
@@ -1831,7 +1883,7 @@ static void __rbd_obj_setup_discard(struct rbd_obj_request *obj_req, 
	u16 opcode;



	if (rbd_obj_is_entire(obj_req)) {

		if (obj_request_overlaps_parent(obj_req)) {

		if (obj_req->num_img_extents) {

			opcode = CEPH_OSD_OP_TRUNCATE;

		} else {

			osd_req_op_init(obj_req->osd_req, which++,
@@ -1858,11 +1910,16 @@ static int rbd_obj_setup_discard(struct rbd_obj_request *obj_req) 
	unsigned int num_osd_ops, which = 0;

	int ret;



	/* reverse map the entire object onto the parent */

	ret = rbd_obj_calc_img_extents(obj_req, true);

	if (ret)

		return ret;



	if (rbd_obj_is_entire(obj_req)) {

		obj_req->write_state = RBD_OBJ_WRITE_FLAT;

		num_osd_ops = 1; /* truncate/delete */

	} else {

		if (obj_request_overlaps_parent(obj_req)) {

		if (obj_req->num_img_extents) {

			obj_req->write_state = RBD_OBJ_WRITE_GUARD;

			num_osd_ops = 2; /* stat + truncate/zero */

		} else {
@@ -1875,8 +1932,7 @@ static int rbd_obj_setup_discard(struct rbd_obj_request *obj_req) 
	if (!obj_req->osd_req)

		return -ENOMEM;



	if (!rbd_obj_is_entire(obj_req) &&

	    obj_request_overlaps_parent(obj_req)) {

	if (!rbd_obj_is_entire(obj_req) && obj_req->num_img_extents) {

		ret = __rbd_obj_setup_stat(obj_req, which++);

		if (ret)

			return ret;
@@ -1980,8 +2036,6 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, 
			ceph_bvec_iter_advance(&bvec_it, length);

		}



		obj_request->img_offset = img_offset;



		img_offset += length;

		resid -= length;

	}
@@ -2009,14 +2063,15 @@ static void rbd_img_request_submit(struct rbd_img_request *img_request) 
	rbd_img_request_put(img_request);

}



static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req,

				    u64 img_offset, u32 bytes)

static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)

{

	struct rbd_img_request *img_req = obj_req->img_request;

	struct rbd_img_request *child_img_req;

	int ret;



	child_img_req = rbd_parent_request_create(obj_req, img_offset, bytes);

	child_img_req = rbd_parent_request_create(obj_req,

					obj_req->img_extents[0].fe_off,

					obj_req->img_extents[0].fe_len);

	if (!child_img_req)

		return -ENOMEM;
@@ -2038,7 +2093,7 @@ static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req, 
	} else {

		struct ceph_bvec_iter it = {

			.bvecs = obj_req->copyup_bvecs,

			.iter = { .bi_size = bytes },

			.iter = { .bi_size = obj_req->img_extents[0].fe_len },

		};



		ret = rbd_img_request_fill(child_img_req, OBJ_REQUEST_BVECS,
@@ -2059,20 +2114,24 @@ static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req) 
	int ret;



	if (obj_req->result == -ENOENT &&

	    obj_req->img_offset < rbd_dev->parent_overlap &&

	    !obj_req->tried_parent) {

		u64 obj_overlap = min(obj_req->ex.oe_len,

			      rbd_dev->parent_overlap - obj_req->img_offset);

	    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;

			return true;

		}



		if (obj_req->num_img_extents) {

			obj_req->tried_parent = true;

		ret = rbd_obj_read_from_parent(obj_req, obj_req->img_offset,

					       obj_overlap);

			ret = rbd_obj_read_from_parent(obj_req);

			if (ret) {

				obj_req->result = ret;

				return true;

			}

			return false;

		}

	}



	/*

	 * -ENOENT means a hole in the image -- zero-fill the entire
@@ -2189,11 +2248,12 @@ static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap) 
static int rbd_obj_handle_write_guard(struct rbd_obj_request *obj_req)

{

	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;

	u64 img_offset;

	u64 obj_overlap;

	int ret;



	if (!obj_request_overlaps_parent(obj_req)) {

	rbd_assert(obj_req->num_img_extents);

	prune_extents(obj_req->img_extents, &obj_req->num_img_extents,

		      rbd_dev->parent_overlap);

	if (!obj_req->num_img_extents) {

		/*

		 * The overlap has become 0 (most likely because the

		 * image has been flattened).  Use rbd_obj_issue_copyup()
@@ -2207,29 +2267,12 @@ static int rbd_obj_handle_write_guard(struct rbd_obj_request *obj_req) 
		return rbd_obj_issue_copyup(obj_req, 0);

	}



	/*

	 * Determine the byte range covered by the object in the

	 * child image to which the original request was to be sent.

	 */

	img_offset = obj_req->img_offset - obj_req->ex.oe_off;

	obj_overlap = rbd_dev->layout.object_size;



	/*

	 * There is no defined parent data beyond the parent

	 * overlap, so limit what we read at that boundary if

	 * necessary.

	 */

	if (img_offset + obj_overlap > rbd_dev->parent_overlap) {

		rbd_assert(img_offset < rbd_dev->parent_overlap);

		obj_overlap = rbd_dev->parent_overlap - img_offset;

	}



	ret = setup_copyup_bvecs(obj_req, obj_overlap);

	ret = setup_copyup_bvecs(obj_req, rbd_obj_img_extents_bytes(obj_req));

	if (ret)

		return ret;



	obj_req->write_state = RBD_OBJ_WRITE_COPYUP;

	return rbd_obj_read_from_parent(obj_req, img_offset, obj_overlap);

	return rbd_obj_read_from_parent(obj_req);

}



static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req)
@@ -2335,6 +2378,9 @@ 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;