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2017-09-14Merge tag 'for-4.14/dm-changes' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - Some request-based DM core and DM multipath fixes and cleanups - Constify a few variables in DM core and DM integrity - Add bufio optimization and checksum failure accounting to DM integrity - Fix DM integrity to avoid checking integrity of failed reads - Fix DM integrity to use init_completion - A couple DM log-writes target fixes - Simplify DAX flushing by eliminating the unnecessary flush abstraction that was stood up for DM's use. * tag 'for-4.14/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dax: remove the pmem_dax_ops->flush abstraction dm integrity: use init_completion instead of COMPLETION_INITIALIZER_ONSTACK dm integrity: make blk_integrity_profile structure const dm integrity: do not check integrity for failed read operations dm log writes: fix >512b sectorsize support dm log writes: don't use all the cpu while waiting to log blocks dm ioctl: constify ioctl lookup table dm: constify argument arrays dm integrity: count and display checksum failures dm integrity: optimize writing dm-bufio buffers that are partially changed dm rq: do not update rq partially in each ending bio dm rq: make dm-sq requeuing behavior consistent with dm-mq behavior dm mpath: complain about unsupported __multipath_map_bio() return values dm mpath: avoid that building with W=1 causes gcc 7 to complain about fall-through
2017-08-28dm: constify argument arraysEric Biggers1-2/+2
The arrays of 'struct dm_arg' are never modified by the device-mapper core, so constify them so that they are placed in .rodata. (Exception: the args array in dm-raid cannot be constified because it is allocated on the stack and modified.) Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-08-23block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig1-2/+2
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>
2017-06-09block: switch bios to blk_status_tChristoph Hellwig1-16/+18
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>
2017-06-09dm: change ->end_io calling conventionChristoph Hellwig1-2/+2
Turn the error paramter into a pointer so that target drivers can change the value, and make sure only DM_ENDIO_* values are returned from the methods. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-15dm cache: simplify the IDLE vs BUSY state calculationJoe Thornber1-6/+3
Drop the MODERATE state since it wasn't buying us much. Also, in check_migrations(), prepare for the next commit ("dm cache policy smq: don't do any writebacks unless IDLE") by deferring to the policy to make the final decision on whether writebacks can be serviced. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-05-15dm cache: track all IO to the cache rather than just the origin device's IOJoe Thornber1-8/+7
IO tracking used to throttle writebacks when the origin device is busy. Even if all the IO is going to the fast device, writebacks can significantly degrade performance. So track all IO to gauge whether the cache is busy or not. Otherwise, synthetic IO tests (e.g. fio) that might send all IO to the fast device wouldn't cause writebacks to get throttled. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-05-15dm cache: fix incorrect 'idle_time' reset in IO trackerJoe Thornber1-0/+3
Some bios have no payload (eg, a FLUSH), don't reset the idle_time when these come in. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-05-03Merge tag 'for-4.12/dm-changes' of ↵Linus Torvalds1-1388/+1087
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - A major update for DM cache that reduces the latency for deciding whether blocks should migrate to/from the cache. The bio-prison-v2 interface supports this improvement by enabling direct dispatch of work to workqueues rather than having to delay the actual work dispatch to the DM cache core. So the dm-cache policies are much more nimble by being able to drive IO as they see fit. One immediate benefit from the improved latency is a cache that should be much more adaptive to changing workloads. - Add a new DM integrity target that emulates a block device that has additional per-sector tags that can be used for storing integrity information. - Add a new authenticated encryption feature to the DM crypt target that builds on the capabilities provided by the DM integrity target. - Add MD interface for switching the raid4/5/6 journal mode and update the DM raid target to use it to enable aid4/5/6 journal write-back support. - Switch the DM verity target over to using the asynchronous hash crypto API (this helps work better with architectures that have access to off-CPU algorithm providers, which should reduce CPU utilization). - Various request-based DM and DM multipath fixes and improvements from Bart and Christoph. - A DM thinp target fix for a bio structure leak that occurs for each discard IFF discard passdown is enabled. - A fix for a possible deadlock in DM bufio and a fix to re-check the new buffer allocation watermark in the face of competing admin changes to the 'max_cache_size_bytes' tunable. - A couple DM core cleanups. * tag 'for-4.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (50 commits) dm bufio: check new buffer allocation watermark every 30 seconds dm bufio: avoid a possible ABBA deadlock dm mpath: make it easier to detect unintended I/O request flushes dm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit() dm mpath: micro-optimize the hot path relative to MPATHF_QUEUE_IF_NO_PATH dm: introduce enum dm_queue_mode to cleanup related code dm mpath: verify __pg_init_all_paths locking assumptions at runtime dm: verify suspend_locking assumptions at runtime dm block manager: remove an unused argument from dm_block_manager_create() dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue() dm mpath: delay requeuing while path initialization is in progress dm mpath: avoid that path removal can trigger an infinite loop dm mpath: split and rename activate_path() to prepare for its expanded use dm ioctl: prevent stack leak in dm ioctl call dm integrity: use previously calculated log2 of sectors_per_block dm integrity: use hex2bin instead of open-coded variant dm crypt: replace custom implementation of hex2bin() dm crypt: remove obsolete references to per-CPU state dm verity: switch to using asynchronous hash crypto API dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues ...
2017-04-08block: remove the discard_zeroes_data flagChristoph Hellwig1-1/+0
Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can kill this hack. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-31dm cache: set/clear the cache core's dirty_bitset when loading mappingsJoe Thornber1-0/+6
When loading metadata make sure to set/clear the dirty bits in the cache core's dirty_bitset as well as the policy. Otherwise the cache core is unaware that any blocks were dirty when the cache was last shutdown. A very serious side-effect being that the cleaner policy would therefore never be tasked with writing back dirty data from a cache that was in writeback mode (e.g. when switching from smq policy to cleaner policy when decommissioning a writeback cache). This fixes a serious data corruption bug associated with writeback mode. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-03-07dm cache: significant rework to leverage dm-bio-prison-v2Joe Thornber1-1388/+1081
The cache policy interfaces have been updated to work well with the new bio-prison v2 interface's ability to queue work immediately (promotion, demotion, etc) -- overriding benefit being reduced latency on processing IO through the cache. Previously such work would be left for the DM cache core to queue on various lists and then process in batches later -- this caused a serious delay in latency for IO driven by the cache. The background tracker code was factored out so that all cache policies can make use of it. Also, the "cleaner" policy has been removed and is now a variant of the smq policy that simply disallows migrations. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-03-07dm bio prison v2: new interface for the bio prisonJoe Thornber1-1/+1
The deferred set is gone and all methods have _v2 appended to the end of their names to allow for continued use of the original bio prison in DM thin-provisioning. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-02-21Merge tag 'dm-4.11-changes' of ↵Linus Torvalds1-19/+25
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - Fix dm-raid transient device failure processing and other smaller tweaks. - Add journal support to the DM raid target to close the 'write hole' on raid 4/5/6. - Fix dm-cache corruption, due to rounding bug, when cache exceeds 2TB. - Add 'metadata2' feature to dm-cache to separate the dirty bitset out from other cache metadata. This improves speed of shutting down a large cache device (which implies writing out dirty bits). - Fix a memory leak during dm-stats data structure destruction. - Fix a DM multipath round-robin path selector performance regression that was caused by less precise balancing across all paths. - Lastly, introduce a DM core fix for a long-standing DM snapshot deadlock that is rooted in the complexity of the device stack used in conjunction with block core maintaining bios on current->bio_list to manage recursion in generic_make_request(). A more comprehensive fix to block core (and its hook in the cpu scheduler) would be wonderful but this DM-specific fix is pragmatic considering how difficult it has been to make progress on a generic fix. * tag 'dm-4.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (22 commits) dm: flush queued bios when process blocks to avoid deadlock dm round robin: revert "use percpu 'repeat_count' and 'current_path'" dm stats: fix a leaked s->histogram_boundaries array dm space map metadata: constify dm_space_map structures dm cache metadata: use cursor api in blocks_are_clean_separate_dirty() dm persistent data: add cursor skip functions to the cursor APIs dm cache metadata: use dm_bitset_new() to create the dirty bitset in format 2 dm bitset: add dm_bitset_new() dm cache metadata: name the cache block that couldn't be loaded dm cache metadata: add "metadata2" feature dm cache metadata: use bitset cursor api to load discard bitset dm bitset: introduce cursor api dm btree: use GFP_NOFS in dm_btree_del() dm space map common: memcpy the disk root to ensure it's arch aligned dm block manager: add unlikely() annotations on dm_bufio error paths dm cache: fix corruption seen when using cache > 2TB dm raid: cleanup awkward branching in raid_message() option processing dm raid: use mddev rather than rdev->mddev dm raid: use read_disk_sb() throughout dm raid: add raid4/5/6 journaling support ...
2017-02-16dm cache metadata: add "metadata2" featureJoe Thornber1-16/+22
If "metadata2" is provided as a table argument when creating/loading a cache target a more compact metadata format, with separate dirty bits, is used. "metadata2" improves speed of shutting down a cache target. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-02-16dm cache: fix corruption seen when using cache > 2TBJoe Thornber1-3/+3
A rounding bug due to compiler generated temporary being 32bit was found in remap_to_cache(). A localized cast in remap_to_cache() fixes the corruption but this preferred fix (changing from uint32_t to sector_t) eliminates potential for future rounding errors elsewhere. Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-02-02block: Use pointer to backing_dev_info from request_queueJan Kara1-1/+1
We will want to have struct backing_dev_info allocated separately from struct request_queue. As the first step add pointer to backing_dev_info to request_queue and convert all users touching it. No functional changes in this patch. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27block: add a op_is_flush helperChristoph Hellwig1-10/+3
This centralizes the checks for bios that needs to be go into the flush state machine. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-21dm cache: add missing cache device name to DMERR in set_cache_mode()Mike Snitzer1-1/+2
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-08-07block: rename bio bi_rw to bi_opfJens Axboe1-4/+4
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>
2016-06-07block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSHMike Christie1-6/+6
To avoid confusion between REQ_OP_FLUSH, which is handled by request_fn drivers, and upper layers requesting the block layer perform a flush sequence along with possibly a WRITE, this patch renames REQ_FLUSH to REQ_PREFLUSH. 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>
2016-06-07dm: use bio op accessorsMike Christie1-4/+6
Separate the op from the rq_flag_bits and have dm set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-11dm cache: bump the target versionMike Snitzer1-1/+1
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-03-11dm cache: make sure every metadata function checks fail_ioJoe Thornber1-2/+10
Otherwise operations may be attempted that will only ever go on to crash (since the metadata device is either missing or unreliable if 'fail_io' is set). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2016-02-23dm: rename target's per_bio_data_size to per_io_data_sizeMike Snitzer1-1/+1
Request-based DM will also make use of per_bio_data_size. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-12-10dm: don't save and restore bi_privateMikulas Patocka1-3/+0
Device mapper used the field bi_private to point to dm_target_io. However, since kernel 3.15, the bi_private field is unused, and so the targets do not need to save and restore this field. This patch removes code that saves and restores bi_private from dm-cache, dm-snapshot and dm-verity. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-01dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()Julia Lawall1-2/+1
Remove DM's unneeded NULL tests before calling these destroy functions, now that they check for NULL, thanks to these v4.3 commits: 3942d2991 ("mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()") 4e3ca3e03 ("mm/mempool: allow NULL `pool' pointer in mempool_destroy()") The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x; @@ -if (x != NULL) \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-09-03Merge tag 'dm-4.3-changes' of ↵Linus Torvalds1-20/+19
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper update from Mike Snitzer: - a couple small cleanups in dm-cache, dm-verity, persistent-data's dm-btree, and DM core. - a 4.1-stable fix for dm-cache that fixes the leaking of deferred bio prison cells - a 4.2-stable fix that adds feature reporting for the dm-stats features added in 4.2 - improve DM-snapshot to not invalidate the on-disk snapshot if snapshot device write overflow occurs; but a write overflow triggered through the origin device will still invalidate the snapshot. - optimize DM-thinp's async discard submission a bit now that late bio splitting has been included in block core. - switch DM-cache's SMQ policy lock from using a mutex to a spinlock; improves performance on very low latency devices (eg. NVMe SSD). - document DM RAID 4/5/6's discard support [ I did not pull the slab changes, which weren't appropriate for this tree, and weren't obviously the right thing to do anyway. At the very least they need some discussion and explanation before getting merged. Because not pulling the actual tagged commit but doing a partial pull instead, this merge commit thus also obviously is missing the git signature from the original tag ] * tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm cache: fix use after freeing migrations dm cache: small cleanups related to deferred prison cell cleanup dm cache: fix leaking of deferred bio prison cells dm raid: document RAID 4/5/6 discard support dm stats: report precise_timestamps and histogram in @stats_list output dm thin: optimize async discard submission dm snapshot: don't invalidate on-disk image on snapshot write overflow dm: remove unlikely() before IS_ERR() dm: do not override error code returned from dm_get_device() dm: test return value for DM_MAPIO_SUBMITTED dm verity: remove unused mempool dm cache: move wake_waker() from free_migrations() to where it is needed dm btree remove: remove unused function get_nr_entries() dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling() dm cache policy smq: change the mutex to a spinlock
2015-09-02Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-32/+13
Pull core block updates from Jens Axboe: "This first core part of the block IO changes contains: - Cleanup of the bio IO error signaling from Christoph. We used to rely on the uptodate bit and passing around of an error, now we store the error in the bio itself. - Improvement of the above from myself, by shrinking the bio size down again to fit in two cachelines on x86-64. - Revert of the max_hw_sectors cap removal from a revision again, from Jeff Moyer. This caused performance regressions in various tests. Reinstate the limit, bump it to a more reasonable size instead. - Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me. Most devices have huge trim limits, which can cause nasty latencies when deleting files. Enable the admin to configure the size down. We will look into having a more sane default instead of UINT_MAX sectors. - Improvement of the SGP gaps logic from Keith Busch. - Enable the block core to handle arbitrarily sized bios, which enables a nice simplification of bio_add_page() (which is an IO hot path). From Kent. - Improvements to the partition io stats accounting, making it faster. From Ming Lei. - Also from Ming Lei, a basic fixup for overflow of the sysfs pending file in blk-mq, as well as a fix for a blk-mq timeout race condition. - Ming Lin has been carrying Kents above mentioned patches forward for a while, and testing them. Ming also did a few fixes around that. - Sasha Levin found and fixed a use-after-free problem introduced by the bio->bi_error changes from Christoph. - Small blk cgroup cleanup from Viresh Kumar" * 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits) blk: Fix bio_io_vec index when checking bvec gaps block: Replace SG_GAPS with new queue limits mask block: bump BLK_DEF_MAX_SECTORS to 2560 Revert "block: remove artifical max_hw_sectors cap" blk-mq: fix race between timeout and freeing request blk-mq: fix buffer overflow when reading sysfs file of 'pending' Documentation: update notes in biovecs about arbitrarily sized bios block: remove bio_get_nr_vecs() fs: use helper bio_add_page() instead of open coding on bi_io_vec block: kill merge_bvec_fn() completely md/raid5: get rid of bio_fits_rdev() md/raid5: split bio for chunk_aligned_read block: remove split code in blkdev_issue_{discard,write_same} btrfs: remove bio splitting and merge_bvec_fn() calls bcache: remove driver private bio splitting code block: simplify bio_add_page() block: make generic_make_request handle arbitrarily sized bios blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL) block: don't access bio->bi_error after bio_put() block: shrink struct bio down to 2 cache lines again ...
2015-09-01dm cache: fix use after freeing migrationsJoe Thornber1-6/+9
Both free_io_migration() and issue_discard() dereference a migration that was just freed. Fix those by saving off the migrations's cache object before freeing the migration. Also cleanup needless mg->cache dereferences now that the cache object is available directly. Fixes: e44b6a5a3c ("dm cache: move wake_waker() from free_migrations() to where it is needed") Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-08-31dm cache: small cleanups related to deferred prison cell cleanupMike Snitzer1-15/+6
Eliminate __cell_release() since it only had one caller that always released the cell holder. Switch cell_error_with_code() to using free_prison_cell() for the sake of consistency. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-08-31dm cache: fix leaking of deferred bio prison cellsJoe Thornber1-0/+4
There were two cases where dm_cell_visit_release() was being called, which removes the cell from the prison's rbtree, but the callers didn't also return the cell to the mempool. Fix this by having them call free_prison_cell(). This leak manifested as the 'kmalloc-96' slab growing until OOM. Fixes: 651f5fa2a3 ("dm cache: defer whole cells") Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 4.1+
2015-08-13block: kill merge_bvec_fn() completelyKent Overstreet1-21/+0
As generic_make_request() is now able to handle arbitrarily sized bios, it's no longer necessary for each individual block driver to define its own ->merge_bvec_fn() callback. Remove every invocation completely. Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@kernel.org> Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-12dm cache: move wake_waker() from free_migrations() to where it is neededJoe Thornber1-1/+2
This stops spurious wake ups from calls to prealloc_free_structs(). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-07-29dm cache: fix device destroy hang due to improper prealloc_used accountingMike Snitzer1-3/+3
Commit 665022d72f9 ("dm cache: avoid calls to prealloc_free_structs() if possible") introduced a regression that caused the removal of a DM cache device to hang in cache_postsuspend()'s call to wait_for_migrations() with the following stack trace: [<ffffffff81651457>] schedule+0x37/0x80 [<ffffffffa041e21b>] cache_postsuspend+0xbb/0x470 [dm_cache] [<ffffffff810ba970>] ? prepare_to_wait_event+0xf0/0xf0 [<ffffffffa0006f77>] dm_table_postsuspend_targets+0x47/0x60 [dm_mod] [<ffffffffa0001eb5>] __dm_destroy+0x215/0x250 [dm_mod] [<ffffffffa0004113>] dm_destroy+0x13/0x20 [dm_mod] [<ffffffffa00098cd>] dev_remove+0x10d/0x170 [dm_mod] [<ffffffffa00097c0>] ? dev_suspend+0x240/0x240 [dm_mod] [<ffffffffa0009f85>] ctl_ioctl+0x255/0x4d0 [dm_mod] [<ffffffff8127ac00>] ? SYSC_semtimedop+0x280/0xe10 [<ffffffffa000a213>] dm_ctl_ioctl+0x13/0x20 [dm_mod] [<ffffffff811fd432>] do_vfs_ioctl+0x2d2/0x4b0 [<ffffffff81117d5f>] ? __audit_syscall_entry+0xaf/0x100 [<ffffffff81022636>] ? do_audit_syscall_entry+0x66/0x70 [<ffffffff811fd689>] SyS_ioctl+0x79/0x90 [<ffffffff81023e58>] ? syscall_trace_leave+0xb8/0x110 [<ffffffff81654f6e>] entry_SYSCALL_64_fastpath+0x12/0x71 Fix this by accounting for the call to prealloc_data_structs() immediately _before_ the call as opposed to after. This is needed because it is possible to break out of the control loop after the call to prealloc_data_structs() but before prealloc_used was set to true. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-07-29Revert "dm cache: do not wake_worker() in free_migration()"Mike Snitzer1-0/+1
This reverts commit 386cb7cdeeef97e0bf082a8d6bbfc07a2ccce07b. Taking the wake_worker() out of free_migration() will slow writeback dramatically, and hence adaptability. Say we have 10k blocks that need writing back, but are only able to issue 5 concurrently due to the migration bandwidth: it's imperative that we wake_worker() immediately after migration completion; waiting for the next 1 second wake up (via do_waker) means it'll take a long time to write that all back. Reported-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig1-11/+13
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>
2015-07-17dm cache: avoid calls to prealloc_free_structs() if possibleMike Snitzer1-3/+12
If no work was performed then prealloc_data_structs() wasn't ever called so there isn't any need to call prealloc_free_structs(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-07-17dm cache: avoid preallocation if no work in writeback_some_dirty_blocks()Mike Snitzer1-9/+4
Refactor writeback_some_dirty_blocks() to avoid prealloc_data_structs() if the policy doesn't have any dirty blocks ready for writeback. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-07-17dm cache: do not wake_worker() in free_migration()Mike Snitzer1-1/+0
All methods that queue work call wake_worker() as you'd expect. E.g. cell_defer, defer_bio, quiesce_migration (which is called by writeback, promote, demote_then_promote, invalidate, discard, etc). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-07-16dm cache: display 'needs_check' in status if it is setMike Snitzer1-2/+7
There is currently no way to see that the needs_check flag has been set in the metadata. Display 'needs_check' in the cache status if it is set in the cache metadata. Also, update cache documentation. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-06-12dm cache: age and write back cache entries even without active IOJoe Thornber1-2/+2
The policy tick() method is normally called from interrupt context. Both the mq and smq policies do some bottom half work for the tick method in their map functions. However if no IO is going through the cache, then that bottom half work doesn't occur. With these policies this means recently hit entries do not age and do not get written back as early as we'd like. Fix this by introducing a new 'can_block' parameter to the tick() method. When this is set the bottom half work occurs immediately. 'can_block' is set when the tick method is called every second by the core target (not in interrupt context). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-06-12dm cache: prefix all DMERR and DMINFO messages with cache device nameMike Snitzer1-38/+64
Having the DM device name associated with the ERR or INFO message is very helpful. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-06-12dm cache: add fail io mode and needs_check flagJoe Thornber1-28/+176
If a cache metadata operation fails (e.g. transaction commit) the cache's metadata device will abort the current transaction, set a new needs_check flag, and the cache will transition to "read-only" mode. If aborting the transaction or setting the needs_check flag fails the cache will transition to "fail-io" mode. Once needs_check is set the cache device will not be allowed to activate. Activation requires write access to metadata. Future work is needed to add proper support for running the cache in read-only mode. Once in fail-io mode the cache will report a status of "Fail". Also, add commit() wrapper that will disallow commits if in read_only or fail mode. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-06-12dm cache: wake the worker thread every time we free a migration objectJoe Thornber1-3/+6
When the cache is idle, writeback work was only being issued every second. With this change outstanding writebacks are streamed constantly. This offers a writeback performance improvement. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29dm cache: boost promotion of blocks that will be overwrittenJoe Thornber1-7/+7
When considering whether to move a block to the cache we already give preferential treatment to discarded blocks, since they are cheap to promote (no read of the origin required since the data is junk). The same is true of blocks that are about to be completely overwritten, so we likewise boost their promotion chances. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29dm cache: defer whole cellsJoe Thornber1-63/+262
Currently individual bios are deferred to the worker thread if they cannot be processed immediately (eg, a block is in the process of being moved to the fast device). This patch passes whole cells across to the worker. This saves reaquiring the cell, and also collects bios destined for the same block together, which allows them to be mapped with a single look up to the policy. This reduces the overhead of using dm-cache. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29dm cache: pull out some bitset utility functions for reuseJoe Thornber1-24/+0
Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29dm cache: pass a new 'critical' flag to the policies when requesting ↵Joe Thornber1-1/+2
writeback work We only allow non critical writeback if the origin is idle. It is up to the policy to decide what writeback work is critical. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29dm cache: track IO to the origin device using io_trackerJoe Thornber1-7/+49
Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>