Commit 0c425248 authored by Alex Elder's avatar Alex Elder Committed by Sage Weil
Browse files

rbd: define image request flags 



There are several Boolean values we'll be maintaining for image
requests.  Switch from the single write_request field to a
general-purpose flags field, and use one if its bits to represent
the direction of I/O for the image request.  Define helper functions
for setting and testing that flag.

Signed-off-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent 7da22d29

drivers/block/rbd.c

+35 −9
Original line number Diff line number Diff line
@@ -202,12 +202,16 @@ struct rbd_obj_request { 
	struct kref		kref;

};



enum img_req_flags {

	IMG_REQ_WRITE,		/* read = 0, write = 1 */

};



struct rbd_img_request {

	struct request		*rq;

	struct rbd_device	*rbd_dev;

	u64			offset;	/* starting image byte offset */

	u64			length;	/* byte count from offset */

	bool			write_request;	/* false for read */

	unsigned long		flags;

	union {

		struct ceph_snap_context *snapc;	/* for writes */

		u64		snap_id;		/* for reads */
@@ -1210,6 +1214,23 @@ static bool obj_request_done_test(struct rbd_obj_request *obj_request) 
	return atomic_read(&obj_request->done) != 0;

}



/*

 * The default/initial value for all image request flags is 0.  Each

 * is conditionally set to 1 at image request initialization time

 * and currently never change thereafter.

 */

static void img_request_write_set(struct rbd_img_request *img_request)

{

	set_bit(IMG_REQ_WRITE, &img_request->flags);

	smp_mb();

}



static bool img_request_write_test(struct rbd_img_request *img_request)

{

	smp_mb();

	return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;

}



static void

rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)

{
@@ -1369,8 +1390,9 @@ static struct ceph_osd_request *rbd_osd_req_create( 
	struct ceph_osd_request *osd_req;



	if (img_request) {

		rbd_assert(img_request->write_request == write_request);

		if (img_request->write_request)

		rbd_assert(write_request ==

				img_request_write_test(img_request));

		if (write_request)

			snapc = img_request->snapc;

	}
@@ -1494,17 +1516,20 @@ static struct rbd_img_request *rbd_img_request_create( 
			kfree(img_request);

			return NULL;	/* Shouldn't happen */

		}



	}



	img_request->rq = NULL;

	img_request->rbd_dev = rbd_dev;

	img_request->offset = offset;

	img_request->length = length;

	img_request->write_request = write_request;

	if (write_request)

	img_request->flags = 0;

	if (write_request) {

		img_request_write_set(img_request);

		img_request->snapc = snapc;

	else

	} else {

		img_request->snap_id = rbd_dev->spec->snap_id;

	}

	spin_lock_init(&img_request->completion_lock);

	img_request->next_completion = 0;

	img_request->callback = NULL;
@@ -1537,7 +1562,7 @@ static void rbd_img_request_destroy(struct kref *kref) 
		rbd_img_obj_request_del(img_request, obj_request);

	rbd_assert(img_request->obj_request_count == 0);



	if (img_request->write_request)

	if (img_request_write_test(img_request))

		ceph_put_snap_context(img_request->snapc);



	kfree(img_request);
@@ -1580,7 +1605,8 @@ static void rbd_img_obj_callback(struct rbd_obj_request *obj_request) 
			struct rbd_device *rbd_dev = img_request->rbd_dev;



			rbd_warn(rbd_dev, "%s %llx at %llx (%llx)\n",

				img_request->write_request ? "write" : "read",

				img_request_write_test(img_request) ? "write"

								    : "read",

				obj_request->length, obj_request->img_offset,

				obj_request->offset);

			rbd_warn(rbd_dev, "  result %d xferred %x\n",
@@ -1608,7 +1634,7 @@ static int rbd_img_request_fill_bio(struct rbd_img_request *img_request, 
	struct rbd_device *rbd_dev = img_request->rbd_dev;

	struct rbd_obj_request *obj_request = NULL;

	struct rbd_obj_request *next_obj_request;

	bool write_request = img_request->write_request;

	bool write_request = img_request_write_test(img_request);

	unsigned int bio_offset;

	u64 img_offset;

	u64 resid;

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