forked from Minki/linux
33d32fa712
When requesting a detach, we first suspend IO, and also inhibit meta-data IO by means of drbd_md_get_buffer(), because we don't want to "fail" the disk while there is IO in-flight: the transition into D_FAILED for detach purposes may get misinterpreted as actual IO error in a confused endio function. We wrap it all into wait_event(), to retry in case the drbd_req_state() returns SS_IN_TRANSIENT_STATE, as it does for example during an ongoing connection handshake. In that example, the receiver thread may need to grab drbd_md_get_buffer() during the handshake to make progress. To avoid potential deadlock with detach, detach needs to grab and release the meta data buffer inside of that wait_event retry loop. To avoid lock inversion between mutex_lock(&device->state_mutex) and drbd_md_get_buffer(device), introduce a new enum chg_state_flag CS_INHIBIT_MD_IO, and move the call to drbd_md_get_buffer() inside the state_mutex grabbed in drbd_req_state(). Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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| .. | ||
| drbd_actlog.c | ||
| drbd_bitmap.c | ||
| drbd_debugfs.c | ||
| drbd_debugfs.h | ||
| drbd_int.h | ||
| drbd_interval.c | ||
| drbd_interval.h | ||
| drbd_main.c | ||
| drbd_nl.c | ||
| drbd_nla.c | ||
| drbd_nla.h | ||
| drbd_proc.c | ||
| drbd_protocol.h | ||
| drbd_receiver.c | ||
| drbd_req.c | ||
| drbd_req.h | ||
| drbd_state_change.h | ||
| drbd_state.c | ||
| drbd_state.h | ||
| drbd_strings.c | ||
| drbd_strings.h | ||
| drbd_vli.h | ||
| drbd_worker.c | ||
| Kconfig | ||
| Makefile | ||