Define a flag indicating whether an image request originated from the Linux block layer (from blk_fetch_request()) or whether it was initiated in order to satisfy an object request for a child image of a layered rbd device. For image requests initiated by objects of child images we'll save a pointer to the object request rather than the Linux block request.
For now, only block requests are used. Signed-off-by: Alex Elder <[email protected]> --- drivers/block/rbd.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 5ea2e36..7ecd909 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -203,18 +203,22 @@ struct rbd_obj_request { }; enum img_req_flags { - IMG_REQ_WRITE, /* read = 0, write = 1 */ + IMG_REQ_WRITE, /* I/O direction: read = 0, write = 1 */ + IMG_REQ_CHILD, /* initiator: block = 0, child image = 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 */ unsigned long flags; union { + u64 snap_id; /* for reads */ struct ceph_snap_context *snapc; /* for writes */ - u64 snap_id; /* for reads */ + }; + union { + struct request *rq; /* block request */ + struct rbd_obj_request *obj_request; /* obj req initiator */ }; spinlock_t completion_lock;/* protects next_completion */ u32 next_completion; @@ -1231,6 +1235,18 @@ static bool img_request_write_test(struct rbd_img_request *img_request) return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0; } +static void img_request_child_set(struct rbd_img_request *img_request) +{ + set_bit(IMG_REQ_CHILD, &img_request->flags); + smp_mb(); +} + +static bool img_request_child_test(struct rbd_img_request *img_request) +{ + smp_mb(); + return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0; +} + static void rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request) { @@ -1499,7 +1515,8 @@ static void rbd_obj_request_destroy(struct kref *kref) static struct rbd_img_request *rbd_img_request_create( struct rbd_device *rbd_dev, u64 offset, u64 length, - bool write_request) + bool write_request, + bool child_request) { struct rbd_img_request *img_request; struct ceph_snap_context *snapc = NULL; @@ -1530,6 +1547,8 @@ static struct rbd_img_request *rbd_img_request_create( } else { img_request->snap_id = rbd_dev->spec->snap_id; } + if (child_request) + img_request_child_set(img_request); spin_lock_init(&img_request->completion_lock); img_request->next_completion = 0; img_request->callback = NULL; @@ -1578,7 +1597,9 @@ static void rbd_img_obj_callback(struct rbd_obj_request *obj_request) dout("%s: img %p obj %p\n", __func__, img_request, obj_request); rbd_assert(img_request != NULL); + rbd_assert(!img_request_child_test(img_request)) rbd_assert(img_request->rq != NULL); + rbd_assert(img_request->obj_request_count > 0); rbd_assert(which != BAD_WHICH); rbd_assert(which < img_request->obj_request_count); @@ -2012,7 +2033,7 @@ static void rbd_request_fn(struct request_queue *q) result = -ENOMEM; img_request = rbd_img_request_create(rbd_dev, offset, length, - write_request); + write_request, false); if (!img_request) goto end_request; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
