The patch reverts: Subject: [PATCH rh7] ploop: push_backup must pass READs intact
If push_backup is in progress (doesn't matter "full" or "incremental") and ploop state-machine detects incoming WRITE request to the cluster-block that was not push_backup-ed yet, it suspends the request until userspace reports it as "processed". The above is fine, but while such a WRITE request is suspended, only subsequent WRITEs (to given cluster-block) must be suspended too. READs must not. Otherwise userspace backup tool will be blocked infinintely trying to push_backup given cluster-block. Passing READs while blocking WRITEs must be OK because: 1) ploop has not finalized that first WRITE yet; 2) given cluster-block will be kept intact (non-modified) while the WRITE is suspended. https://jira.sw.ru/browse/PSBM-46775 Signed-off-by: Maxim Patlasov <[email protected]> --- drivers/block/ploop/dev.c | 7 ------- include/linux/ploop/ploop.h | 1 - 2 files changed, 8 deletions(-) diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c index 96f7850..d3f0ec0 100644 --- a/drivers/block/ploop/dev.c +++ b/drivers/block/ploop/dev.c @@ -1137,11 +1137,6 @@ static int check_lockout(struct ploop_request *preq) else if (preq->req_cluster > p->req_cluster) n = n->rb_right; else { - /* do not block backup tool READs from /dev/ploop */ - if (!(preq->req_rw & REQ_WRITE) && - test_bit(PLOOP_REQ_ALLOW_READS, &p->state)) - return 0; - list_add_tail(&preq->list, &p->delay_list); plo->st.bio_lockouts++; trace_preq_lockout(preq, p); @@ -2053,7 +2048,6 @@ restart: ploop_pb_clear_bit(plo->pbd, preq->req_cluster); } else { spin_lock_irq(&plo->lock); - __set_bit(PLOOP_REQ_ALLOW_READS, &preq->state); ploop_add_lockout(preq, 0); spin_unlock_irq(&plo->lock); /* @@ -2072,7 +2066,6 @@ restart: spin_lock_irq(&plo->lock); del_lockout(preq); - __clear_bit(PLOOP_REQ_ALLOW_READS, &preq->state); if (!list_empty(&preq->delay_list)) list_splice_init(&preq->delay_list, plo->ready_queue.prev); spin_unlock_irq(&plo->lock); diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h index 0fba25e..77fd833 100644 --- a/include/linux/ploop/ploop.h +++ b/include/linux/ploop/ploop.h @@ -470,7 +470,6 @@ enum PLOOP_REQ_KAIO_FSYNC, /*force image fsync by KAIO module */ PLOOP_REQ_POST_SUBMIT, /* preq needs post_submit processing */ PLOOP_REQ_PUSH_BACKUP, /* preq was ACKed by userspace push_backup */ - PLOOP_REQ_ALLOW_READS, /* READs are allowed for given req_cluster */ PLOOP_REQ_FSYNC_DONE, /* fsync_thread() performed f_op->fsync() */ }; _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
