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| author | Ilya Dryomov <idryomov@gmail.com> | 2019-01-08 21:47:38 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-17 00:07:12 +0300 |
| commit | 022ce60cc621c84df6d0272984e791f60983fd7a (patch) | |
| tree | 21bd022c19cd5d3cdd23472b1538491917f8e498 /drivers/block/rbd.c | |
| parent | 8b99f1705b5d545c23fc629e51063915e7bb3fce (diff) | |
| download | linux-022ce60cc621c84df6d0272984e791f60983fd7a.tar.xz | |
rbd: don't return 0 on unmap if RBD_DEV_FLAG_REMOVING is set
commit 85f5a4d666fd9be73856ed16bb36c5af5b406b29 upstream.
There is a window between when RBD_DEV_FLAG_REMOVING is set and when
the device is removed from rbd_dev_list. During this window, we set
"already" and return 0.
Returning 0 from write(2) can confuse userspace tools because
0 indicates that nothing was written. In particular, "rbd unmap"
will retry the write multiple times a second:
10:28:05.463299 write(4, "0", 1) = 0
10:28:05.463509 write(4, "0", 1) = 0
10:28:05.463720 write(4, "0", 1) = 0
10:28:05.463942 write(4, "0", 1) = 0
10:28:05.464155 write(4, "0", 1) = 0
Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/block/rbd.c')
| -rw-r--r-- | drivers/block/rbd.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 9057dad2a64c..f2b1994d58a0 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -6308,7 +6308,6 @@ static ssize_t do_rbd_remove(struct bus_type *bus, struct list_head *tmp; int dev_id; char opt_buf[6]; - bool already = false; bool force = false; int ret; @@ -6341,13 +6340,13 @@ static ssize_t do_rbd_remove(struct bus_type *bus, spin_lock_irq(&rbd_dev->lock); if (rbd_dev->open_count && !force) ret = -EBUSY; - else - already = test_and_set_bit(RBD_DEV_FLAG_REMOVING, - &rbd_dev->flags); + else if (test_and_set_bit(RBD_DEV_FLAG_REMOVING, + &rbd_dev->flags)) + ret = -EINPROGRESS; spin_unlock_irq(&rbd_dev->lock); } spin_unlock(&rbd_dev_list_lock); - if (ret < 0 || already) + if (ret) return ret; if (force) { |