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* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 91Thomas Gleixner2019-05-241-13/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 or at your option any later version [drbd] is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with [drbd] see the file copying if not write to the free software foundation 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 16 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520075212.050796421@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* crypto: shash - remove shash_desc::flagsEric Biggers2019-04-251-2/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | The flags field in 'struct shash_desc' never actually does anything. The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP. However, no shash algorithm ever sleeps, making this flag a no-op. With this being the case, inevitably some users who can't sleep wrongly pass MAY_SLEEP. These would all need to be fixed if any shash algorithm actually started sleeping. For example, the shash_ahash_*() functions, which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP from the ahash API to the shash API. However, the shash functions are called under kmap_atomic(), so actually they're assumed to never sleep. Even if it turns out that some users do need preemption points while hashing large buffers, we could easily provide a helper function crypto_shash_update_large() which divides the data into smaller chunks and calls crypto_shash_update() and cond_resched() for each chunk. It's not necessary to have a flag in 'struct shash_desc', nor is it necessary to make individual shash algorithms aware of this at all. Therefore, remove shash_desc::flags, and document that the crypto_shash_*() functions can be called from any context. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire")Lars Ellenberg2018-12-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | And also re-enable partial-zero-out + discard aligned. With the introduction of REQ_OP_WRITE_ZEROES, we started to use that for both WRITE_ZEROES and DISCARDS, hoping that WRITE_ZEROES would "do what we want", UNMAP if possible, zero-out the rest. The example scenario is some LVM "thin" backend. While an un-allocated block on dm-thin reads as zeroes, on a dm-thin with "skip_block_zeroing=true", after a partial block write allocated that block, that same block may well map "undefined old garbage" from the backends on LBAs that have not yet been written to. If we cannot distinguish between zero-out and discard on the receiving side, to avoid "undefined old garbage" to pop up randomly at later times on supposedly zero-initialized blocks, we'd need to map all discards to zero-out on the receiving side. But that would potentially do a full alloc on thinly provisioned backends, even when the expectation was to unmap/trim/discard/de-allocate. We need to distinguish on the protocol level, whether we need to guarantee zeroes (and thus use zero-out, potentially doing the mentioned full-alloc), or if we want to put the emphasis on discard, and only do a "best effort zeroing" (by "discarding" blocks aligned to discard-granularity, and zeroing only potential unaligned head and tail clippings to at least *try* to avoid "false positives" in an online-verify later), hoping that someone set skip_block_zeroing=false. For some discussion regarding this on dm-devel, see also https://www.mail-archive.com/dm-devel%40redhat.com/msg07965.html https://www.redhat.com/archives/dm-devel/2018-January/msg00271.html For backward compatibility, P_TRIM means zero-out, unless the DRBD_FF_WZEROES feature flag is agreed upon during handshake. To have upper layers even try to submit WRITE ZEROES requests, we need to announce "efficient zeroout" independently. We need to fixup max_write_zeroes_sectors after blk_queue_stack_limits(): if we can handle "zeroes" efficiently on the protocol, we want to do that, even if our backend does not announce max_write_zeroes_sectors itself. Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Finish renaming REQ_DISCARD into REQ_OP_DISCARDBart Van Assche2018-10-041-1/+1
| | | | | | | | | | | | | | Some time ago REQ_DISCARD was renamed into REQ_OP_DISCARD. Some comments and documentation files were not updated however. Update these comments and documentation files. See also commit 4e1b2d52a80d ("block, fs, drivers: remove REQ_OP compat defs and related code"). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* drbd: Convert from ahash to shashKees Cook2018-09-061-31/+32
| | | | | | | | | | | | | | | | | | | | In preparing to remove all stack VLA usage from the kernel[1], this removes the discouraged use of AHASH_REQUEST_ON_STACK in favor of the smaller SHASH_DESC_ON_STACK by converting from ahash-wrapped-shash to direct shash. By removing a layer of indirection this both improves performance and reduces stack usage. The stack allocation will be made a fixed size in a later patch to the crypto subsystem. The bulk of the lines in this change are simple s/ahash/shash/, but the main logic differences are in drbd_csum_ee() and drbd_csum_bio(), which externalizes the page walking with k(un)map_atomic() instead of using scattergather. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Add part_stat_read_accum to read across field entries.Michael Callahan2018-07-181-3/+1Star
| | | | | | | | | | | | | Add a part_stat_read_accum macro to genhd.h to read and sum across field entries. For example to sum up the number read and write sectors completed. In addition to being ar reasonable cleanup by itself this will make it easier to add new stat fields in the future. tj: Refreshed on top of v4.17. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* drbd: fix access after freeLars Ellenberg2018-07-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have struct drbd_requests { ... struct bio *private_bio; ... } to hold a bio clone for local submission. On local IO completion, we put that bio, and in case we want to use the result later, we overload that member to hold the ERR_PTR() of the completion result, Which, before v4.3, used to be the passed in "int error", so we could first bio_put(), then assign. v4.3-rc1~100^2~21 4246a0b63bd8 block: add a bi_error field to struct bio changed that: bio_put(req->private_bio); - req->private_bio = ERR_PTR(error); + req->private_bio = ERR_PTR(bio->bi_error); Which introduces an access after free, because it was non obvious that req->private_bio == bio. Impact of that was mostly unnoticable, because we only use that value in a multiple-failure case, and even then map any "unexpected" error code to EIO, so worst case we could potentially mask a more specific error with EIO in a multiple failure case. Unless the pointed to memory region was unmapped, as is the case with CONFIG_DEBUG_PAGEALLOC, in which case this results in BUG: unable to handle kernel paging request v4.13-rc1~70^2~75 4e4cbee93d56 block: switch bios to blk_status_t changes it further to bio_put(req->private_bio); req->private_bio = ERR_PTR(blk_status_to_errno(bio->bi_status)); And blk_status_to_errno() now contains a WARN_ON_ONCE() for unexpected values, which catches this "sometimes", if the memory has been reused quickly enough for other things. Should also go into stable since 4.3, with the trivial change around 4.13. Cc: stable@vger.kernel.org Fixes: 4246a0b63bd8 block: add a bi_error field to struct bio Reported-by: Sarah Newman <srn@prgmr.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* drbd: Convert timers to use timer_setup()Kees Cook2017-11-061-4/+4
| | | | | | | | | | | In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: drbd-dev@lists.linbit.com Signed-off-by: Kees Cook <keescook@chromium.org>
* drbd: abort drbd_start_resync if there is no connectionRoland Kammerer2017-08-291-0/+5
| | | | | | | | | | This was found by a static analysis tool. While highly unlikely, be sure to return without dereferencing the NULL pointer. Reported-by: Shaobo <shaobo@cs.utah.edu> 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>
* drbd: fix potential get_ldev/put_ldev refcount imbalance during attachLars Ellenberg2017-08-291-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Race: drbd_adm_attach() | async drbd_md_endio() | device->ldev is still NULL. | | drbd_md_read( | .endio = drbd_md_endio; | submit; | .... | wait for done == 1; | done = 1; ); | wake_up(); .. lot of other stuff, | .. includeing taking and | ...giving up locks, | .. doing further IO, | .. stuff that takes "some time" | | while in this context, | this is the next statement. | which means this context was scheduled .. only then, finally, | away for "some time". device->ldev = nbc; | | if (device->ldev) | put_ldev() Unlikely, but possible. I was able to provoke it "reliably" by adding an mdelay(500); after the wake_up(). Fixed by moving the if (!NULL) put_ldev() before done = 1; Impact of the bug was that the resulting refcount imbalance could lead to premature destruction of the object, potentially causing a NULL pointer dereference during a subsequent detach. 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>
* drbd: mark symbols static where possibleBaoyou Xie2017-08-291-1/+2
| | | | | | | | | | | | | | | | | We get a few warnings when building kernel with W=1: drbd/drbd_receiver.c:1224:6: warning: no previous prototype for 'one_flush_endio' [-Wmissing-prototypes] drbd/drbd_req.c:1450:6: warning: no previous prototype for 'send_and_submit_pending' [-Wmissing-prototypes] drbd/drbd_main.c:924:6: warning: no previous prototype for 'assign_p_sizes_qlim' [-Wmissing-prototypes] .... In fact, these functions are only used in the file in which they are declared and don't need a declaration, but can be made static. So this patch marks these functions with 'static'. Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org> 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>
* drbd: Send P_NEG_ACK upon write error in protocol != CLars Ellenberg2017-08-291-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In protocol != C, we forgot to send the P_NEG_ACK for failing writes. Once we no longer submit to local disk, because we already "detached", due to the typical "on-io-error detach;" config setting, we already send the neg acks right away. Only those requests that have been submitted, and have been error-completed by the local disk, would forget to send the neg-ack, and only in asynchronous replication (protocol != C). Unless this happened during resync, where we already always send acks, regardless of protocol. The primary side needs the P_NEG_ACK in order to mark the affected block(s) for resync in its out-of-sync bitmap. If the blocks in question are not re-written again, we may miss to resync them later, causing data inconsistencies. This patch will always send the neg-acks, and also at least try to persist the out-of-sync status on the local node already. 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>
* drbd: introduce drbd_recv_header_maybe_unplugLars Ellenberg2017-08-291-5/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recently, drbd_recv_header() was changed to potentially implicitly "unplug" the backend device(s), in case there is currently nothing to receive. Be more explicit about it: re-introduce the original drbd_recv_header(), and introduce a new drbd_recv_header_maybe_unplug() for use by the receiver "main loop". Using explicit plugging via blk_start_plug(); blk_finish_plug(); really helps the io-scheduler of the backend with merging requests. Wrap the receiver "main loop" with such a plug. Also catch unplug events on the Primary, and try to propagate. This is performance relevant. Without this, if the receiving side does not merge requests, number of IOPS on the peer can me significantly higher than IOPS on the Primary, and can easily become the bottleneck. Together, both changes should help to reduce the number of IOPS as seen on the backend of the receiving side, by increasing the chance of merging mergable requests, without trading latency for more throughput. 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>
* block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig2017-08-231-1/+1
| | | | | | | | | | | | | | | | | | | | This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: switch bios to blk_status_tChristoph Hellwig2017-06-091-8/+8
| | | | | | | | | | Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: implement REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-081-1/+3
| | | | | | | | | It seems like DRBD assumes its on the wire TRIM request always zeroes data. Use that fact to implement REQ_OP_WRITE_ZEROES. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar2017-03-021-1/+1
| | | | | | | | | | | | | <linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* block: rename bio bi_rw to bi_opfJens Axboe2016-08-071-1/+1
| | | | | | | | | | | | | Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe <axboe@fb.com>
* block: get rid of bio_rw and READAChristoph Hellwig2016-07-211-11/+19
| | | | | | | | | | | | | | | These two are confusing leftover of the old world order, combining values of the REQ_OP_ and REQ_ namespaces. For callers that don't special case we mostly just replace bi_rw with bio_data_dir or op_is_write, except for the few cases where a switch over the REQ_OP_ values makes more sense. Any check for READA is replaced with an explicit check for REQ_RAHEAD. Also remove the READA alias for REQ_RAHEAD. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: code cleanups without semantic changesFabian Frederick2016-06-141-5/+4Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | This contains various cosmetic fixes ranging from simple typos to const-ifying, and using booleans properly. Original commit messages from Fabian's patch set: drbd: debugfs: constify drbd_version_fops drbd: use seq_put instead of seq_print where possible drbd: include linux/uaccess.h instead of asm/uaccess.h drbd: use const char * const for drbd strings drbd: kerneldoc warning fix in w_e_end_data_req() drbd: use unsigned for one bit fields drbd: use bool for peer is_ states drbd: fix typo drbd: use | for bitmask combination drbd: use true/false for bool drbd: fix drbd_bm_init() comments drbd: introduce peer state union drbd: fix maybe_pull_ahead() locking comments drbd: use bool for growing drbd: remove redundant declarations drbd: replace if/BUG by BUG_ON Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Roland Kammerer <roland.kammerer@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: introduce WRITE_SAME supportLars Ellenberg2016-06-141-2/+6
| | | | | | | | | | | | | | | We will support WRITE_SAME, if * all peers support WRITE_SAME (both in kernel and DRBD version), * all peer devices support WRITE_SAME * logical_block_size is identical on all peers. We may at some point introduce a fallback on the receiving side for devices/kernels that do not support WRITE_SAME, by open-coding a submit loop. But not yet. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: introduce unfence-peer handlerLars Ellenberg2016-06-141-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When resync is finished, we already call the "after-resync-target" handler (on the former sync target, obviously), once per volume. Paired with the before-resync-target handler, you can create snapshots, before the resync causes the volumes to become inconsistent, and discard those snapshots again, once they are no longer needed. It was also overloaded to be paired with the "fence-peer" handler, to "unfence" once the volumes are up-to-date and known good. This has some disadvantages, though: we call "fence-peer" for the whole connection (once for the group of volumes), but would call unfence as side-effect of after-resync-target once for each volume. Also, we fence on a (current, or about to become) Primary, which will later become the sync-source. Calling unfence only as a side effect of the after-resync-target handler opens a race window, between a new fence on the Primary (SyncTarget) and the unfence on the SyncTarget, which is difficult to close without some kind of "cluster wide lock" in those handlers. We would not need those handlers if we could still communicate. Which makes trying to aquire a cluster wide lock from those handlers seem like a very bad idea. This introduces the "unfence-peer" handler, which will be called per connection (once for the group of volumes), just like the fence handler, only once all volumes are back in sync, and on the SyncSource. Which is expected to be the node that previously called "fence", the node that is currently allowed to be Primary, and thus the only node that could trigger a new "fence" that could race with this unfence. Which makes us not need any cluster wide synchronization here, serializing two scripts running on the same node is trivial. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: Create the protocol feature THIN_RESYNCPhilipp Reisner2016-06-141-1/+12
| | | | | | | | | | | If thinly provisioned volumes are used, during a resync the sync source tries to find out if a block is deallocated. If it is deallocated, then the resync target uses block_dev_issue_zeroout() on the range in question. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: Implement handling of thinly provisioned storage on resync target nodesPhilipp Reisner2016-06-141-1/+28
| | | | | | | | | If during resync we read only zeroes for a range of sectors assume that these secotors can be discarded on the sync target node. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: use bio op accessorsMike Christie2016-06-071-3/+4
| | | | | | | | | | Separate the op from the rq_flag_bits and have drbd set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: Use shash and ahashHerbert Xu2016-01-271-19/+24
| | | | | | | This patch replaces uses of the long obsolete hash interface with either shash (for non-SG users) or ahash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* drbd: make drbd known to lsblk: use bd_link_disk_holderLars Ellenberg2015-11-251-1/+1
| | | | | | | | | | | | | | lsblk should be able to pick up stacking device driver relations involving DRBD conveniently. Even though upstream kernel since 2011 says "DON'T USE THIS UNLESS YOU'RE ALREADY USING IT." a new user has been added since (bcache), which sets the precedences for us to use it as well. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: Create a dedicated workqueue for sending acks on the control connectionPhilipp Reisner2015-11-251-1/+7
| | | | | | | | | | | | | | | | | The intention is to reduce CPU utilization. Recent measurements unveiled that the current performance bottleneck is CPU utilization on the receiving node. The asender thread became CPU limited. One of the main points is to eliminate the idr_for_each_entry() loop from the sending acks code path. One exception in that is sending back ping_acks. These stay in the ack-receiver thread. Otherwise the logic becomes too complicated for no added value. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: improve network timeout detectionLars Ellenberg2015-11-251-0/+2
| | | | | | | | | Don't blame the peer for being unresponsive, if we did not even ask the question yet. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: drbd_panic_after_delayed_completion_of_aborted_request()Lars Ellenberg2015-11-251-1/+7
| | | | | | | | | | | | | | | | | | The only way to make DRBD intentionally call panic is to set a disk timeout, have that trigger, "abort" some request and complete to upper layers, then have the backend IO subsystem later complete these requests successfully regardless. As the attached IO pages have been recycled for other purposes meanwhile, this will cause unexpected random memory changes. To prevent corruption, we rather panic in that case. Make it obvious from stack traces that this was the case by introducing drbd_panic_after_delayed_completion_of_aborted_request(). Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: Fix locking across all resourcesAndreas Gruenbacher2015-11-251-47/+38Star
| | | | | | | | | | | | | | Instead of using a rwlock for synchronizing state changes across resources, take the request locks of all resources for global state changes. Use resources_mutex to serialize global state changes. This means that taking the request lock of a resource is now enough to prevent changes of that resource. (Previously, a read lock on the global state lock was needed as well.) Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: add a bi_error field to struct bioChristoph Hellwig2015-07-291-33/+11Star
| | | | | | | | | | | | | | | | | | | | | | | | Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: fix resync throttling initializationLars Ellenberg2014-11-101-1/+4
| | | | | | | | | | | | | | | | If for some reason DRBD resync was the only activity on a backend device, drbd_rs_c_min_rate_throttle() would mistakenly decide that it is still initialization time, and keep throttling the resync. This patch explicitly initializes ->rs_last_events to the current backend event counters, and drops the rs_last_events == 0 from the throttle condition. Reported-by: Mikhail Sugakov <msugakov@amazon.de> Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: reduce lock contention in drbd_workerLars Ellenberg2014-09-111-6/+4Star
| | | | | | | | | The worker may now dequeue work items in batches. This should reduce lock contention during busy periods. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: Improve asender performanceLars Ellenberg2014-09-111-10/+1Star
| | | | | | | | | Shorten receive path in the asender thread. Reduces CPU utilisation of asender when receiving packets, and with that increases IOPs. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: Get rid of the WORK_PENDING macroAndreas Gruenbacher2014-09-111-8/+7Star
| | | | | | | | This macro doesn't add any value; just use test_bit() instead. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: Get rid of the __no_warn and __cond_lock macrosAndreas Gruenbacher2014-09-111-3/+6
| | | | | | | | These macros can easily be replaced with its definition. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: Use consistent names for all the bi_end_io callbacksAndreas Gruenbacher2014-09-111-3/+3
| | | | | | | | Now they follow the _endio naming sheme. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: debugfs: add callback_historyLars Ellenberg2014-07-101-3/+34
| | | | | | | | Add a per-connection worker thread callback_history with timing details, call site and callback function. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: track timing details of peer_requestsLars Ellenberg2014-07-101-0/+1
| | | | | | | | | | | | | | | | | | | To be able to present timing details in debugfs, we need to track preparation/submit times of peer requests. Track peer request flags early, before they are put on the epoch_entry lists. Waiting for activity log transactions may be a major latency factor. We want to be able to present the peer_request state accurately in debugfs, and what it is waiting for. Consistently mark/unmark peer requests with EE_CALL_AL_COMPLETE_IO. Set it only *after* calling drbd_al_begin_io(), clear it as soon as we call drbd_al_complete_io(). Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: improve throttling decisions of background resynchronisationLars Ellenberg2014-07-101-7/+2Star
| | | | | | | | | | | | | | | | | | | Background resynchronisation does some "side-stepping", or throttles itself, if it detects application IO activity, and the current resync rate estimate is above the configured "cmin-rate". What was not detected: if there is no application IO, because it blocks on activity log transactions. Introduce a new atomic_t ap_actlog_cnt, tracking such blocked requests, and count non-zero as application IO activity. This counter is exposed at proc_details level 2 and above. Also make sure to release the currently locked resync extent if we side-step due to such voluntary throttling. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: gather detailed timing statistics for drbd_requestsLars Ellenberg2014-07-101-0/+3
| | | | | | | | | | Record (in jiffies) how much time a request spends in which stages. Followup commits will use and present this additional timing information so we can better locate and tackle the root causes of latency spikes, or present the backlog for asynchronous replication. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: track meta data IO intent, start and submit timeLars Ellenberg2014-07-101-6/+3Star
| | | | | | | | | | | | For diagnostic purposes, track intent, start time and latest submit time of meta data IO. Move separate members from struct drbd_device into the embeded struct drbd_md_io. s/md_io_(page|in_use)/md_io.\1/ Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: consistently use list_add_tail for peer_request trackingLars Ellenberg2014-07-101-1/+1
| | | | | | | | | Keep the epoch entry lists (active_ee, read_ee, sync_ee, ...) consistently "oldest first". That way finding the oldest not yet successfully processed request is simply list_first_entry_or_null. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: add drbd_queue_work_if_unqueued helperLars Ellenberg2014-07-101-4/+4
| | | | | | | | | | | | | | | | | | | | | We sometimes do if (list_empty(&w.list)) drbd_queue_work(&q, &w.list); Removal (list_del_init) may happen outside all locks, after all pending work entries have been moved to an on-stack local work list. For not dynamically allocated, but embeded, work structs, we must avoid to re-add until it really was removed. Move that list_empty check inside the spin_lock(&q->q_lock) within the helper function, and change to list_empty_careful(). This may have been the reason for a list_add corruption inside drbd_queue_work(). Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: drbd_rs_number_requests: fix unit mismatch in comparisonLars Ellenberg2014-07-101-4/+9
| | | | | | | | | | | | We try to limit the number of "in-flight" resync requests. One condition for that is the amount of requested data should not exceed half of what can be covered by our "max-buffers" setting. However we compared number of 4k pages with number of in-flight 512 Byte sectors, and this extra throttle triggered much earlier than intended. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: improve resync request throttling due to sendbuf sizeLars Ellenberg2014-07-101-9/+14
| | | | | | | | If we throttle resync because the socket sendbuffer is filling up, tell TCP about it, so it may expand the sendbuffer for us. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: implement csums-after-crash-onlyLars Ellenberg2014-07-101-4/+20
| | | | | | | | | | | | | | | | | | | | Checksum based resync trades CPU cycles for network bandwidth, in situations where we expect much of the to-be-resynced blocks to be actually identical on both sides already. In a "network hickup" scenario, it won't help: all to-be-resynced blocks will typically be different. The use case is for the resync of *potentially* different blocks after crash recovery -- the crash recovery had marked larger areas (those covered by the activity log) as need-to-be-resynced, just in case. Most of those blocks will be identical. This option makes it possible to configure checksum based resync, but only actually use it for the first resync after primary crash. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: get rid of drbd_queue_work_frontLars Ellenberg2014-07-101-4/+2Star
| | | | | | | | | | | | | | The last user was al_write_transaction, if called with "delegate", and the last user to call it with "delegate = true" was the receiver thread, which has no need to delegate, but can call it himself. Finally drop the delegate parameter, drop the extra w_al_write_transaction callback, and drop drbd_queue_work_front. Do not (yet) change dequeue_work_item to dequeue_work_batch, though. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
* drbd: use drbd_device_post_work() in more placesLars Ellenberg2014-07-101-10/+17
| | | | | | | | | | | This replaces the md_sync_work member of struct drbd_device by a new MD_SYNC "work bit" in device->flags. This replaces the resync_start_work member of struct drbd_device by a new RS_START "work bit" in device->flags. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>