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| author | Lars Ellenberg | 2010-10-14 13:57:07 +0200 |
|---|---|---|
| committer | Philipp Reisner | 2010-10-14 19:08:32 +0200 |
| commit | 9d282875d85ebc2b49362310677fc0dcd91b9db9 (patch) | |
| tree | bbbb183462f56b4b065e6dcc5e686587f90ce192 /drivers/block/drbd/drbd_main.c | |
| parent | drbd: cleanup useless leftover warn/error printk's (diff) | |
| download | kernel-qcow2-linux-9d282875d85ebc2b49362310677fc0dcd91b9db9.tar.gz kernel-qcow2-linux-9d282875d85ebc2b49362310677fc0dcd91b9db9.tar.xz kernel-qcow2-linux-9d282875d85ebc2b49362310677fc0dcd91b9db9.zip | |
drbd: drop wrong debug asserts, fix recently introduced race
commit 2372c38caadeaebc68a5ee190782c2a0df01edc3
drbd: fix for possible deadlock on IO error during resync
introduced a new ASSERT, which turns out to be wrong. Drop it.
Also serialize the state change to D_DISKLESS with the after state
change work of the -> D_FAILED transition, don't open a new race.
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_main.c')
| -rw-r--r-- | drivers/block/drbd/drbd_main.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index f89b97466d07..342574f6d92e 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -1393,17 +1393,22 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os, } if (os.disk > D_DISKLESS && ns.disk == D_DISKLESS) { - int c = atomic_read(&mdev->local_cnt); - + /* We must still be diskless, + * re-attach has to be serialized with this! */ + if (mdev->state.disk != D_DISKLESS) + dev_err(DEV, + "ASSERT FAILED: disk is %s while going diskless\n", + drbd_disk_str(mdev->state.disk)); + + /* we cannot assert local_cnt == 0 here, as get_ldev_if_state + * will inc/dec it frequently. Since we became D_DISKLESS, no + * one has touched the protected members anymore, though, so we + * are safe to free them here. */ if (drbd_send_state(mdev)) dev_warn(DEV, "Notified peer that I detached my disk.\n"); else dev_err(DEV, "Sending state for detach failed\n"); - if (c != 0) { - dev_err(DEV, "Logic bug, local_cnt=%d, but should be 0\n", c); - wait_event(mdev->misc_wait, !atomic_read(&mdev->local_cnt)); - } lc_destroy(mdev->resync); mdev->resync = NULL; lc_destroy(mdev->act_log); @@ -3723,8 +3728,10 @@ static int w_bitmap_io(struct drbd_conf *mdev, struct drbd_work *w, int unused) static int w_go_diskless(struct drbd_conf *mdev, struct drbd_work *w, int unused) { D_ASSERT(mdev->state.disk == D_FAILED); - D_ASSERT(atomic_read(&mdev->local_cnt) == 0); - + /* we cannot assert local_cnt == 0 here, as get_ldev_if_state will + * inc/dec it frequently. Once we are D_DISKLESS, no one will touch + * the protected members anymore, though, so in the after_state_ch work + * it will be safe to free them. */ drbd_force_state(mdev, NS(disk, D_DISKLESS)); clear_bit(GO_DISKLESS, &mdev->flags); @@ -3735,7 +3742,10 @@ void drbd_go_diskless(struct drbd_conf *mdev) { D_ASSERT(mdev->state.disk == D_FAILED); if (!test_and_set_bit(GO_DISKLESS, &mdev->flags)) - drbd_queue_work_front(&mdev->data.work, &mdev->go_diskless); + drbd_queue_work(&mdev->data.work, &mdev->go_diskless); + /* don't drbd_queue_work_front, + * we need to serialize with the after_state_ch work + * of the -> D_FAILED transition. */ } /** |