- 16 May, 2014 1 commit
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Ming Lei authored
When there isn't enough vring descriptor for adding to vq, blk-mq will be put as stopped state until some of pending descriptors are completed & freed. Unfortunately, the vq's interrupt may come just before blk-mq's BLK_MQ_S_STOPPED flag is set, so the blk-mq will still be kept as stopped even though lots of descriptors are completed and freed in the interrupt handler. The worst case is that all pending descriptors are freed in the interrupt handler, and the queue is kept as stopped forever. This patch fixes the problem by starting/stopping blk-mq with holding vq_lock. Cc: Jens Axboe <axboe@kernel.dk> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
Ming Lei <tom.leiming@gmail.com> Signed-off-by:
Jens Axboe <axboe@fb.com>
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- 14 May, 2014 3 commits
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Jens Axboe authored
We need to stop the block layer queues to prevent new "normal" IO from entering the driver, while we wait for existing commands to finish. Signed-off-by: -
Dan Carpenter authored
We changed this from blk_alloc_queue_node() to blk_mq_init_queue() so the check needs to be updated as well. Fixes: ffc771b3 ('mtip32xx: convert to use blk-mq') Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Jens Axboe authored
This rips out timeout handling, requeueing, etc in converting it to use blk-mq instead. Acked-by:
Asai Thambi S P <asamymuthupa@micron.com> Signed-off-by:
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- 05 May, 2014 12 commits
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Joe Perches authored
Move the function to the proper spot instead. Signed-off-by:
Joe Perches <joe@perches.com> Signed-off-by:
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Joe Perches authored
Move the function to appropriate locations instead. Signed-off-by:
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Joe Perches authored
Move function to proper location instead. Fix whitespace and embedded if too. Signed-off-by:
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Joe Perches authored
Move the function to the right spot instead. Signed-off-by:
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Joe Perches authored
Move the function instead. Signed-off-by:
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Joe Perches authored
Neaten the spacing too. Signed-off-by:
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Joe Perches authored
It's defined below without being called. Signed-off-by:
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Joe Perches authored
The actual static is defined below it but not used until later. Signed-off-by:
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Joe Perches authored
Move static function to the appropriate place to remove the now unnecessary prototype. Signed-off-by:
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Joe Perches authored
Macros with hidden control flow aren't nice. Just use copy_to/from_user directly instead. Signed-off-by:
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Joe Perches authored
It's unused, make it disappear. Signed-off-by:
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Joe Perches authored
It's a debugging message, mark it so. Signed-off-by:
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- 01 May, 2014 1 commit
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Ming Lei authored
entry(cmd->ll_list) may belong to new request once end_cmd() returns, so fix the bug with the patch. Without the change, it is easy to observe oops when doing null_blk(timer) test. Signed-off-by:
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- 30 Apr, 2014 23 commits
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Lars Ellenberg authored
If there are no peer_devices or connections, I'd rather have NULL than some "arbitrary" address pretending to point to a struct. Helps to avoid hard to debug symptoms, in case we ever try to use and dereference a drbd_connection or drbd_peer_device where we in fact don't have any connection at all. Signed-off-by:
Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by:
Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by:
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Philipp Reisner authored
A newly created device was never exposed before, i.e. has a exposed_data_uuid of 0. Then it is valid to attach to any current_uuid of a backing device (of course also to a newly created one (4)) Signed-off-by:
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Philipp Reisner authored
In case a connection transitions into C_TIMEOUT within the timer function (request_timer_fn()) we need to make sure that the receiver thread (potentially running on a different CPU) sees the updated cstate later on. Signed-off-by:
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Philipp Reisner authored
...instead directly assigning to q->limits.discard_zeroes_data Signed-off-by:
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Lars Ellenberg authored
Just because it is the oldest not yet completed request does not make it the oldest request waiting for disk. Or waiting for the peer. And we completely missed already completed requests that would still hold references to activity log extents, waiting only for the barrier ack. Find two oldest not yet completely processed requests, one that is still waiting for local completion, and one that is still waiting for some response from the peer. These may or may not be the same request object. Then separately apply the network and disk timeouts, respectively. Signed-off-by:
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Philipp Reisner authored
In the implementation as it was, the two peers sent each other a challenge, and expects the challenge hashed with the shared secret back. A attacker could simply wait for the challenge of the peer, and send the same challenge back. Then it waits for the response, and sends the same response back. Prevent this by not accepting a challenge from the peer that is the same as the challenge sent to the peer. Signed-off-by:
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Lars Ellenberg authored
Once our sender thread needs to wait_for_work(), and actually needs to schedule(), just before we do that, we already check if it is useful to implicitly close the last epoch. The condition was too strict: only implicitly close the epoch, if there have been no new (write) requests at all. The assumption was that if there were new requests, they would always be communicated one way or another, and would send necessary epoch separating barriers explicitly. This is not always true, e.g. when becoming diskless, or while explicitly starting a full resync. The last communicated epoch could stay open for a long time, locking down corresponding activity log extents. It is safe to always implicitly send that last barrier, as soon as we determin that there cannot be more requests in the last communicated epoch, even if there have been (uncommunicated) new requests in new epochs meanwhile. Signed-off-by:
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Lars Ellenberg authored
When batching more updates to the activity log into single transactions, we lost the ability for new requests to force themselves into the active set: all preparation steps became non-blocking, and if all currently hot extents keep busy, they could starve out new incoming requests to cold extents for quite a while. This can only happen if your IO backend accepts more IO operations per average DRBD replication round trip time than you have al-extents configured. If we have incoming requests to cold extents, at least do one blocking update per transaction. In an artificial worst-case workload on SSD with an asynchronous 600 ms replication link, with al-extents = 7 (the minimum we allow), and concurrent full resynch, without this patch, some write requests have been observed to be starved for 40 seconds. With this patch, application observed a worst case latency of twice the replication round trip time. Signed-off-by:
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Lars Ellenberg authored
We want to store in persistent meta data what the peer DRBD can handle, which, due to spreading requests to multiple bios, may be more than its backing device can handle. Otherwise, if a disconnected Primary temporarily loses access to its local data as well, we may accidentally shrink the max-bio setting, portentially causing already assembled, but not yet processed, application bios to be spuriously failed due to device limits. Signed-off-by:
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Lars Ellenberg authored
In the drbd make request function, specifically in drbd_send_and_submit(), we decide whether we want to send the actual write request, or only a "set this block out of sync" information. We do so based on the current connection state, while holding the req_lock. The connection state is not supposed to change while holding the req_lock. But in drbd_start_resync, we did change that state anyways, while only holding the global_state_lock, which is enough to change sync-after dependencies (paused vs active resync), but not good enough to change the connection state. Fix: in drbd_start_resync, first grab the req_lock to serialize with drbd_send_and_submit(), before grabbing the global_state_lock to be able to evaluate the sync-after dependencies. Signed-off-by:
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Lars Ellenberg authored
Allow the user of REQ_DISCARD. Signed-off-by:
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Lars Ellenberg authored
Note that I do NOT call __drbd_chk_io_error for failed REQ_DISCARD. That may be wrong, though, or needs to differ between EOPNOTSUPP and other errors... Signed-off-by:
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Lars Ellenberg authored
If the receiver needs to serve a discard request on a queue that does not announce to be discard cabable, it falls back to do synchronous blkdev_issue_zeroout(). We expect only "reasonably" large (up to one activity log extent?) discard requests. We do this to not to not block the receiver for too long in this fallback code path, and to not set/clear too many bits inside one spinlock_irq_save() in drbd_set_in_sync/drbd_set_out_of_sync, Signed-off-by:
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Lars Ellenberg authored
We plan to use genl_family->parallel_ops = true in the future, but need to review all possible interactions first. For now, only selectively drop genl_lock() in drbd_set_role(), instead serializing on our own internal resource->conf_update mutex. We now can be promoted/demoted on many resources in parallel, which may significantly improve cluster failover times when fencing is required. Signed-off-by:
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Lars Ellenberg authored
Because all administrative requests via genetlink have been globally serialized via genl_lock(), we used to have one static struct drbd_config_context "admin context". Move this on-stack to the respective callback functions. This will allow us to selectively drop the genl_lock() (or use genl_family->parallel_ops) in the future. Signed-off-by:
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Philipp Reisner authored
When a 'cluster wide' disconnect executes, the result comes back from the peer, and immediately after that the connection breaks then _conn_rq_cond() reported back SS_CW_SUCCESS. Therefore _conn_request_state() calls conn_set_state(), which has a BUG() in it. The BUG() is hit because conn_is_valid_transition() does not like the transaction. Which goes back to is_valid_soft_transition() returning SS_OUTDATE_WO_CONN. This fix is to consider an error reported by is_valid_soft_transition() even when the peer agreed to the transaction. Signed-off-by:
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Lars Ellenberg authored
Before, application IO could pre-empt resync activity for up to hardcoded 20 seconds per resync request. A very busy server could throttle the effective resync bandwidth down to one request per 20 seconds. Now, we only let application IO pre-empt resync traffic while the current resync rate estimate is above c-min-rate. If you disable the c-min-rate throttle feature (set c-min-rate = 0), application IO will no longer pre-empt resync traffic at all. Signed-off-by:
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Lars Ellenberg authored
If max-buffers and socket buffer sizes are "too small" for the chosen resync rate, this could lead potentially lead to a distributed deadlock, which may or may not resolve itself via the "ko-count" and request timeout mechanism, or could be resolved by forced disconnect. One option to deal with this is proper configuration: use larger max-buffer and socket buffers settings, or reduce the resync rate. But even with bad configuration we should not deadlock, but "gracefully" recover. The issue is avoided by using only up to max-buffers/2 for resync requests, and by using max-buffers not as a hard limit for data buffer allocations, but as a throttle threshold only. Signed-off-by:
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Lars Ellenberg authored
While merging adjacent dirty blocks into resync requests, the resync rate throttle was disregarded. For very low resync rates, the effective rate may have exceeded the intended rate by a larger margin. Signed-off-by:
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Lars Ellenberg authored
If we don't make resync or verify progress for "too long", we want to flag it as "stalled". Since 2010, "use rolling marks for resync speed calculation" this "too long" was wrong by a factor of HZ. With HZ 250, it would have been flagged as stalled after 100 minutes. Hardcode 3 minutes instead. Signed-off-by:
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Philipp Reisner authored
If a user forces the operation he takes the blame in case the peer does not have enough space. No reason to dey this... Signed-off-by:
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Philipp Reisner authored
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Philipp Reisner authored
Actually we are clearing the susp_fen flag if we are not going to call a fencing handler. For setting the susp_fen flag needs to be edge-triggerd, and not level triggered. Signed-off-by:
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