diff options
| author | Lars Ellenberg | 2012-03-26 15:09:44 +0200 |
|---|---|---|
| committer | Philipp Reisner | 2012-11-08 16:58:17 +0100 |
| commit | 81f448629aa25051c47b4d5b81702da8cbe922c3 (patch) | |
| tree | d2df79e1f6a7e442008bd69325e29bd80b06f116 /drivers/block | |
| parent | 38a05c16b8fc855db2294eec36fde2c665b14e8f (diff) | |
drbd: Fix a potential race that could case data inconsistency
When we have a write request and a state change C_WF_BITMAP_S -> C_SYNC_SOURCE
at the same time, and it happens that the line
remote = remote && drbd_should_do_remote(s);
stills sees C_WF_BITMAP_S, and
send_oos = rw == WRITE && drbd_should_send_oos(s);
already sees C_SYNC_SOURCE both are 0.
This causes the write to not be mirrored, but marked as out-of-sync on the
Sync_Source node.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/drbd/drbd_req.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 3e4dc070d3ff..c3f99bde0e11 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -822,6 +822,7 @@ int __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long s int local, remote, send_oos = 0; int err; int ret = 0; + union drbd_dev_state s; /* allocate outside of all locks; */ req = drbd_req_new(mdev, bio); @@ -884,8 +885,9 @@ int __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long s drbd_al_begin_io(mdev, &req->i); } - remote = remote && drbd_should_do_remote(mdev->state); - send_oos = rw == WRITE && drbd_should_send_out_of_sync(mdev->state); + s = mdev->state; + remote = remote && drbd_should_do_remote(s); + send_oos = rw == WRITE && drbd_should_send_out_of_sync(s); D_ASSERT(!(remote && send_oos)); if (!(local || remote) && !drbd_suspended(mdev)) { |