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authorAlex Elder <elder@dreamhost.com>2012-02-08 16:11:14 -0600
committerAlex Elder <elder@dreamhost.com>2012-03-22 10:47:50 -0500
commit32eec68d2f233e8a6ae1cd326022f6862e2b9ce3 (patch)
tree03a1f313541374d091bfa09e6028f18bb8c77c18 /drivers
parent593a9e7b34fa62d703b473ae923a9681556cdf74 (diff)
rbd: don't drop the rbd_id too early
Currently an rbd device's id is released when it is removed, but it is done before the code is run to clean up sysfs-related files (such as /sys/bus/rbd/devices/1). It's possible that an rbd is still in use after the rbd_remove() call has been made. It's essentially the same as an active inode that stays around after it has been removed--until its final close operation. This means that the id shows up as free for reuse at a time it should not be. The effect of this was seen by Jens Rehpoehler, who: - had a filesystem mounted on an rbd device - unmapped that filesystem (without unmounting) - found that the mount still worked properly - but hit a panic when he attempted to re-map a new rbd device This re-map attempt found the previously-unmapped id available. The subsequent attempt to reuse it was met with a panic while attempting to (re-)install the sysfs entry for the new mapped device. Fix this by holding off "putting" the rbd id, until the rbd_device release function is called--when the last reference is finally dropped. Note: This fixes: http://tracker.newdream.net/issues/1907 Signed-off-by: Alex Elder <elder@dreamhost.com> Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/rbd.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 568fa5b1206..6bbd5af1f02 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2421,7 +2421,12 @@ static ssize_t rbd_add(struct bus_type *bus,
if (rc)
goto err_out_blkdev;
- /* set up and announce blkdev mapping */
+ /*
+ * At this point cleanup in the event of an error is the job
+ * of the sysfs code (initiated by rbd_bus_del_dev()).
+ *
+ * Set up and announce blkdev mapping.
+ */
rc = rbd_init_disk(rbd_dev);
if (rc)
goto err_out_bus;
@@ -2433,8 +2438,6 @@ static ssize_t rbd_add(struct bus_type *bus,
return count;
err_out_bus:
- rbd_id_put(rbd_dev);
-
/* this will also clean up rest of rbd_dev stuff */
rbd_bus_del_dev(rbd_dev);
@@ -2492,6 +2495,9 @@ static void rbd_dev_release(struct device *dev)
/* clean up and free blkdev */
rbd_free_disk(rbd_dev);
unregister_blkdev(rbd_dev->major, rbd_dev->name);
+
+ /* done with the id, and with the rbd_dev */
+ rbd_id_put(rbd_dev);
kfree(rbd_dev);
/* release module ref */
@@ -2524,8 +2530,6 @@ static ssize_t rbd_remove(struct bus_type *bus,
goto done;
}
- rbd_id_put(rbd_dev);
-
__rbd_remove_all_snaps(rbd_dev);
rbd_bus_del_dev(rbd_dev);