From 9d475de5d12af8ac4c2101807e0a889ac7389c5a Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 3 Jul 2012 16:01:19 -0500 Subject: [PATCH] rbd: add code to get the size of a v2 rbd image The size of an rbd format 2 image is fetched from the server using a "get_size" method. The same method is used for getting the size of a snapshot, so structure this addition with a generic helper routine that we can get this information for either. Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 53 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 3b284d53a566..061c62496fea 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -2127,6 +2127,47 @@ static char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev, u32 which, return snap_name; } +/* + * Get the size and object order for an image snapshot, or if + * snap_id is CEPH_NOSNAP, gets this information for the base + * image. + */ +static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id, + u8 *order, u64 *snap_size) +{ + __le64 snapid = cpu_to_le64(snap_id); + int ret; + struct { + u8 order; + __le64 size; + } __attribute__ ((packed)) size_buf = { 0 }; + + ret = rbd_req_sync_exec(rbd_dev, rbd_dev->header_name, + "rbd", "get_size", + (char *) &snapid, sizeof (snapid), + (char *) &size_buf, sizeof (size_buf), + CEPH_OSD_FLAG_READ, NULL); + dout("%s: rbd_req_sync_exec returned %d\n", __func__, ret); + if (ret < 0) + return ret; + + *order = size_buf.order; + *snap_size = le64_to_cpu(size_buf.size); + + dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n", + (unsigned long long) snap_id, (unsigned int) *order, + (unsigned long long) *snap_size); + + return 0; +} + +static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev) +{ + return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP, + &rbd_dev->header.obj_order, + &rbd_dev->header.image_size); +} + /* * Scan the rbd device's current snapshot list and compare it to the * newly-received snapshot context. Remove any existing snapshots @@ -2636,6 +2677,7 @@ out_err: static int rbd_dev_v2_probe(struct rbd_device *rbd_dev) { size_t size; + int ret; /* * Image id was filled in by the caller. Record the header @@ -2647,12 +2689,23 @@ static int rbd_dev_v2_probe(struct rbd_device *rbd_dev) return -ENOMEM; sprintf(rbd_dev->header_name, "%s%s", RBD_HEADER_PREFIX, rbd_dev->image_id); + + /* Get the size and object order for the image */ + + ret = rbd_dev_v2_image_size(rbd_dev); + if (ret < 0) + goto out_err; rbd_dev->image_format = 2; dout("discovered version 2 image, header name is %s\n", rbd_dev->header_name); return -ENOTSUPP; +out_err: + kfree(rbd_dev->header_name); + rbd_dev->header_name = NULL; + + return ret; } /* -- 2.39.5