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| author | Lars Ellenberg | 2010-10-16 12:13:47 +0200 |
|---|---|---|
| committer | Philipp Reisner | 2010-10-22 15:46:11 +0200 |
| commit | 82f59cc6353889b426cf13b6596d5a3d100fa09e (patch) | |
| tree | 6d5a678516334f0a37a56a509b84322a0352719b /drivers/block/drbd/drbd_receiver.c | |
| parent | drbd: tag a few error messages with "assert failed" (diff) | |
| download | kernel-qcow2-linux-82f59cc6353889b426cf13b6596d5a3d100fa09e.tar.gz kernel-qcow2-linux-82f59cc6353889b426cf13b6596d5a3d100fa09e.tar.xz kernel-qcow2-linux-82f59cc6353889b426cf13b6596d5a3d100fa09e.zip | |
drbd: fix potential deadlock on detach
If we have contention in drbd_al_begin_iod (heavy randon IO),
an administrative request to detach the disk may deadlock
for similar reasons as the recently fixed deadlock if detaching
because of IO-error.
The approach taken here is to either go through the intermediate
cleanup state D_FAILED, or first lock out application io,
don't just go directly to D_DISKLESS.
We need an additional state bit (WAS_IO_ERROR) to distinguish
the -> D_FAILED because of IO-error from other failures.
Sanitize D_ATTACHING -> D_FAILED to D_ATTACHING -> D_DISKLESS.
If only attaching, ldev may be missing still, but would be referenced
from within the after_state_ch for -> D_FAILED, potentially
dereferencing a NULL pointer.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Diffstat (limited to 'drivers/block/drbd/drbd_receiver.c')
| -rw-r--r-- | drivers/block/drbd/drbd_receiver.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 6ec922c623a1..04a823b01da5 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -3363,7 +3363,7 @@ static int receive_state(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned if (ns.conn == C_MASK) { ns.conn = C_CONNECTED; if (mdev->state.disk == D_NEGOTIATING) { - drbd_force_state(mdev, NS(disk, D_DISKLESS)); + drbd_force_state(mdev, NS(disk, D_FAILED)); } else if (peer_state.disk == D_NEGOTIATING) { dev_err(DEV, "Disk attach process on the peer node was aborted.\n"); peer_state.disk = D_DISKLESS; |