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authorIlya Dryomov <idryomov@gmail.com>2020-03-16 17:52:54 +0300
committerIlya Dryomov <idryomov@gmail.com>2020-04-13 09:55:49 +0300
commit952c48b0ed18919bff7528501e9a3fff8a24f8cd (patch)
treecb1c4416ad298503d23abd3298da76bfbf3c5634 /drivers/block/rbd.c
parent0e4e1de5b63fa423b13593337a27fd2d2b0bcf77 (diff)
downloadlinux-952c48b0ed18919bff7528501e9a3fff8a24f8cd.tar.xz
rbd: call rbd_dev_unprobe() after unwatching and flushing notifies
rbd_dev_unprobe() is supposed to undo most of rbd_dev_image_probe(), including rbd_dev_header_info(), which means that rbd_dev_header_info() isn't supposed to be called after rbd_dev_unprobe(). However, rbd_dev_image_release() calls rbd_dev_unprobe() before rbd_unregister_watch(). This is racy because a header update notify can sneak in: "rbd unmap" thread ceph-watch-notify worker rbd_dev_image_release() rbd_dev_unprobe() free and zero out header rbd_watch_cb() rbd_dev_refresh() rbd_dev_header_info() read in header The same goes for "rbd map" because rbd_dev_image_probe() calls rbd_dev_unprobe() on errors. In both cases this results in a memory leak. Fixes: fd22aef8b47c ("rbd: move rbd_unregister_watch() call into rbd_dev_image_release()") Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Jason Dillaman <dillaman@redhat.com>
Diffstat (limited to 'drivers/block/rbd.c')
-rw-r--r--drivers/block/rbd.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index ff2377e6d12c..7aec8bc5df6e 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -6898,9 +6898,10 @@ static void rbd_print_dne(struct rbd_device *rbd_dev, bool is_snap)
static void rbd_dev_image_release(struct rbd_device *rbd_dev)
{
- rbd_dev_unprobe(rbd_dev);
if (rbd_dev->opts)
rbd_unregister_watch(rbd_dev);
+
+ rbd_dev_unprobe(rbd_dev);
rbd_dev->image_format = 0;
kfree(rbd_dev->spec->image_id);
rbd_dev->spec->image_id = NULL;
@@ -6950,7 +6951,7 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
if (ret) {
if (ret == -ENOENT && !need_watch)
rbd_print_dne(rbd_dev, false);
- goto err_out_watch;
+ goto err_out_probe;
}
/*
@@ -6995,12 +6996,11 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
return 0;
err_out_probe:
- rbd_dev_unprobe(rbd_dev);
-err_out_watch:
if (!depth)
up_write(&rbd_dev->header_rwsem);
if (need_watch)
rbd_unregister_watch(rbd_dev);
+ rbd_dev_unprobe(rbd_dev);
err_out_format:
rbd_dev->image_format = 0;
kfree(rbd_dev->spec->image_id);