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author | Alex Elder <elder@inktank.com> | 2013-05-06 17:40:33 -0500 |
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committer | Alex Elder <elder@inktank.com> | 2013-05-08 20:16:55 -0500 |
commit | 1f3ef78861ac4b510175e177899b9b5ba4bbed91 (patch) | |
tree | edf2c0b20d647f495bf7d596f72b08349115d772 /drivers/block | |
parent | 7ce4eef7b5fad73b365b7e4b8892af3af72d4bd3 (diff) | |
download | linux-stable-1f3ef78861ac4b510175e177899b9b5ba4bbed91.tar.gz linux-stable-1f3ef78861ac4b510175e177899b9b5ba4bbed91.tar.bz2 linux-stable-1f3ef78861ac4b510175e177899b9b5ba4bbed91.zip |
rbd: only set up watch for mapped images
Any changes to parent images are immaterial to any mapped clone.
So there is no need to have a watch event registered on header
objects except for the header object of an image that is mapped.
In fact, a watch request is a write operation, and we may only
have read access to a parent image.
We can't set up the watch request until we know the name of the
header object though. So pass a flag to rbd_dev_image_probe() to
indicate whether this probe is for a mapping or for a parent image.
Change the second parameter to rbd_dev_header_watch_sync() be
Boolean while we're at it.
This resolves:
http://tracker.ceph.com/issues/4941
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/rbd.c | 43 |
1 files changed, 24 insertions, 19 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index dbfc44a9defd..e417704de8ca 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -358,7 +358,7 @@ static ssize_t rbd_add(struct bus_type *bus, const char *buf, size_t count); static ssize_t rbd_remove(struct bus_type *bus, const char *buf, size_t count); -static int rbd_dev_image_probe(struct rbd_device *rbd_dev); +static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping); static struct bus_attribute rbd_bus_attrs[] = { __ATTR(add, S_IWUSR, NULL, rbd_add), @@ -2664,7 +2664,7 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data) * Request sync osd watch/unwatch. The value of "start" determines * whether a watch request is being initiated or torn down. */ -static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start) +static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, bool start) { struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; struct rbd_obj_request *obj_request; @@ -2698,7 +2698,7 @@ static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start) rbd_dev->watch_request->osd_req); osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH, - rbd_dev->watch_event->cookie, 0, start); + rbd_dev->watch_event->cookie, 0, start ? 1 : 0); rbd_osd_req_format_write(obj_request); ret = rbd_obj_request_submit(osdc, obj_request); @@ -4549,7 +4549,7 @@ static int rbd_dev_probe_parent(struct rbd_device *rbd_dev) if (!parent) goto out_err; - ret = rbd_dev_image_probe(parent); + ret = rbd_dev_image_probe(parent, false); if (ret < 0) goto out_err; rbd_dev->parent = parent; @@ -4654,12 +4654,7 @@ static int rbd_dev_header_name(struct rbd_device *rbd_dev) static void rbd_dev_image_release(struct rbd_device *rbd_dev) { - int ret; - rbd_dev_unprobe(rbd_dev); - ret = rbd_dev_header_watch_sync(rbd_dev, 0); - if (ret) - rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret); kfree(rbd_dev->header_name); rbd_dev->header_name = NULL; rbd_dev->image_format = 0; @@ -4671,9 +4666,11 @@ static void rbd_dev_image_release(struct rbd_device *rbd_dev) /* * Probe for the existence of the header object for the given rbd - * device. + * device. If this image is the one being mapped (i.e., not a + * parent), initiate a watch on its header object before using that + * object to get detailed information about the rbd image. */ -static int rbd_dev_image_probe(struct rbd_device *rbd_dev) +static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping) { int ret; int tmp; @@ -4693,9 +4690,11 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev) if (ret) goto err_out_format; - ret = rbd_dev_header_watch_sync(rbd_dev, 1); - if (ret) - goto out_header_name; + if (mapping) { + ret = rbd_dev_header_watch_sync(rbd_dev, true); + if (ret) + goto out_header_name; + } if (rbd_dev->image_format == 1) ret = rbd_dev_v1_header_info(rbd_dev); @@ -4719,9 +4718,12 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev) err_out_probe: rbd_dev_unprobe(rbd_dev); err_out_watch: - tmp = rbd_dev_header_watch_sync(rbd_dev, 0); - if (tmp) - rbd_warn(rbd_dev, "unable to tear down watch request\n"); + if (mapping) { + tmp = rbd_dev_header_watch_sync(rbd_dev, false); + if (tmp) + rbd_warn(rbd_dev, "unable to tear down " + "watch request (%d)\n", tmp); + } out_header_name: kfree(rbd_dev->header_name); rbd_dev->header_name = NULL; @@ -4788,7 +4790,7 @@ static ssize_t rbd_add(struct bus_type *bus, rbdc = NULL; /* rbd_dev now owns this */ spec = NULL; /* rbd_dev now owns this */ - rc = rbd_dev_image_probe(rbd_dev); + rc = rbd_dev_image_probe(rbd_dev, true); if (rc < 0) goto err_out_rbd_dev; @@ -4910,10 +4912,13 @@ static ssize_t rbd_remove(struct bus_type *bus, spin_unlock_irq(&rbd_dev->lock); if (ret < 0) goto done; - ret = count; rbd_bus_del_dev(rbd_dev); + ret = rbd_dev_header_watch_sync(rbd_dev, false); + if (ret) + rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret); rbd_dev_image_release(rbd_dev); module_put(THIS_MODULE); + ret = count; done: mutex_unlock(&ctl_mutex); |