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| author | Philipp Reisner <philipp.reisner@linbit.com> | 2012-01-16 12:14:01 +0100 |
|---|---|---|
| committer | Philipp Reisner <philipp.reisner@linbit.com> | 2012-05-09 15:16:34 +0200 |
| commit | fc28845bc005995b41ae8c83c7922d088f0ad228 (patch) | |
| tree | cb5f28c4c0cfb06f46b9e1b0d7e7efcdfc132f90 /drivers/block/drbd | |
| parent | 031a7c173ffda664ac5551bd13c313e513dd87a7 (diff) | |
| download | linux-fc28845bc005995b41ae8c83c7922d088f0ad228.tar.gz linux-fc28845bc005995b41ae8c83c7922d088f0ad228.tar.xz linux-fc28845bc005995b41ae8c83c7922d088f0ad228.zip | |
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/drbd')
| -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 810070146862..4fc7f98d9856 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -786,6 +786,7 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio, uns int local, remote, send_oos = 0; int err = -EIO; int ret = 0; + union drbd_state s; /* allocate outside of all locks; */ req = drbd_req_new(mdev, bio); @@ -847,8 +848,9 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio, uns drbd_al_begin_io(mdev, sector); } - remote = remote && drbd_should_do_remote(mdev->state); - send_oos = rw == WRITE && drbd_should_send_oos(mdev->state); + s = mdev->state; + remote = remote && drbd_should_do_remote(s); + send_oos = rw == WRITE && drbd_should_send_oos(s); D_ASSERT(!(remote && send_oos)); if (!(local || remote) && !is_susp(mdev->state)) { |