From 0407759971cdbd302e0efcb03ff9435a0d3db3ab Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Wed, 23 Jul 2014 17:11:20 +0400 Subject: [PATCH] rbd: split rbd_dev_spec_update() into two functions rbd_dev_spec_update() has two modes of operation, with nothing in common between them. Split it into two functions, one for each mode and make our expectations more clear. Signed-off-by: Ilya Dryomov Reviewed-by: Alex Elder --- drivers/block/rbd.c | 79 ++++++++++++++++++++++++++++++++--------------------- 1 file changed, 48 insertions(+), 31 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 4541f60..23df177 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -3798,6 +3798,9 @@ static struct rbd_spec *rbd_spec_alloc(void) spec = kzalloc(sizeof (*spec), GFP_KERNEL); if (!spec) return NULL; + + spec->pool_id = CEPH_NOPOOL; + spec->snap_id = CEPH_NOSNAP; kref_init(&spec->kref); return spec; @@ -4257,18 +4260,38 @@ static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name) } /* - * When an rbd image has a parent image, it is identified by the - * pool, image, and snapshot ids (not names). This function fills - * in the names for those ids. (It's OK if we can't figure out the - * name for an image id, but the pool and snapshot ids should always - * exist and have names.) All names in an rbd spec are dynamically - * allocated. + * An image being mapped will have everything but the snap id. + */ +static int rbd_spec_fill_snap_id(struct rbd_device *rbd_dev) +{ + struct rbd_spec *spec = rbd_dev->spec; + + rbd_assert(spec->pool_id != CEPH_NOPOOL && spec->pool_name); + rbd_assert(spec->image_id && spec->image_name); + rbd_assert(spec->snap_name); + + if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) { + u64 snap_id; + + snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name); + if (snap_id == CEPH_NOSNAP) + return -ENOENT; + + spec->snap_id = snap_id; + } else { + spec->snap_id = CEPH_NOSNAP; + } + + return 0; +} + +/* + * A parent image will have all ids but none of the names. * - * When an image being mapped (not a parent) is probed, we have the - * pool name and pool id, image name and image id, and the snapshot - * name. The only thing we're missing is the snapshot id. + * All names in an rbd spec are dynamically allocated. It's OK if we + * can't figure out the name for an image id. */ -static int rbd_dev_spec_update(struct rbd_device *rbd_dev) +static int rbd_spec_fill_names(struct rbd_device *rbd_dev) { struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; struct rbd_spec *spec = rbd_dev->spec; @@ -4277,24 +4300,9 @@ static int rbd_dev_spec_update(struct rbd_device *rbd_dev) const char *snap_name; int ret; - /* - * An image being mapped will have the pool name (etc.), but - * we need to look up the snapshot id. - */ - if (spec->pool_name) { - if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) { - u64 snap_id; - - snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name); - if (snap_id == CEPH_NOSNAP) - return -ENOENT; - spec->snap_id = snap_id; - } else { - spec->snap_id = CEPH_NOSNAP; - } - - return 0; - } + rbd_assert(spec->pool_id != CEPH_NOPOOL); + rbd_assert(spec->image_id); + rbd_assert(spec->snap_id != CEPH_NOSNAP); /* Get the pool name; we have to make our own copy of this */ @@ -4313,7 +4321,7 @@ static int rbd_dev_spec_update(struct rbd_device *rbd_dev) if (!image_name) rbd_warn(rbd_dev, "unable to get image name"); - /* Look up the snapshot name, and make a copy */ + /* Fetch the snapshot name */ snap_name = rbd_snap_name(rbd_dev, spec->snap_id); if (IS_ERR(snap_name)) { @@ -4326,10 +4334,10 @@ static int rbd_dev_spec_update(struct rbd_device *rbd_dev) spec->snap_name = snap_name; return 0; + out_err: kfree(image_name); kfree(pool_name); - return ret; } @@ -5158,7 +5166,16 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping) if (ret) goto err_out_watch; - ret = rbd_dev_spec_update(rbd_dev); + /* + * If this image is the one being mapped, we have pool name and + * id, image name and id, and snap name - need to fill snap id. + * Otherwise this is a parent image, identified by pool, image + * and snap ids - need to fill in names for those ids. + */ + if (mapping) + ret = rbd_spec_fill_snap_id(rbd_dev); + else + ret = rbd_spec_fill_names(rbd_dev); if (ret) goto err_out_probe; -- 2.7.4