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2020-12-01dm writecache: remove BUG() and fail gracefully insteadMike Snitzer
Building on arch/s390/ results in this build error: cc1: some warnings being treated as errors ../drivers/md/dm-writecache.c: In function 'persistent_memory_claim': ../drivers/md/dm-writecache.c:323:1: error: no return statement in function returning non-void [-Werror=return-type] Fix this by replacing the BUG() with an -EOPNOTSUPP return. Fixes: 48debafe4f2f ("dm: add writecache target") Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-11-17dm writecache: fix the maximum number of argumentsMikulas Patocka
Advance the maximum number of arguments to 16. This fixes issue where certain operations, combined with table configured args, exceed 10 arguments. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-11-17dm writecache: advance the number of arguments when reporting max_ageMikulas Patocka
When reporting the "max_age" value the number of arguments must advance by two. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: 3923d4854e18 ("dm writecache: implement gradual cleanup") Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-10-12Merge tag 'ras_updates_for_v5.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RAS updates from Borislav Petkov: - Extend the recovery from MCE in kernel space also to processes which encounter an MCE in kernel space but while copying from user memory by sending them a SIGBUS on return to user space and umapping the faulty memory, by Tony Luck and Youquan Song. - memcpy_mcsafe() rework by splitting the functionality into copy_mc_to_user() and copy_mc_to_kernel(). This, as a result, enables support for new hardware which can recover from a machine check encountered during a fast string copy and makes that the default and lets the older hardware which does not support that advance recovery, opt in to use the old, fragile, slow variant, by Dan Williams. - New AMD hw enablement, by Yazen Ghannam and Akshay Gupta. - Do not use MSR-tracing accessors in #MC context and flag any fault while accessing MCA architectural MSRs as an architectural violation with the hope that such hw/fw misdesigns are caught early during the hw eval phase and they don't make it into production. - Misc fixes, improvements and cleanups, as always. * tag 'ras_updates_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Allow for copy_mc_fragile symbol checksum to be generated x86/mce: Decode a kernel instruction to determine if it is copying from user x86/mce: Recover from poison found while copying from user space x86/mce: Avoid tail copy when machine check terminated a copy from user x86/mce: Add _ASM_EXTABLE_CPY for copy user access x86/mce: Provide method to find out the type of an exception handler x86/mce: Pass pointer to saved pt_regs to severity calculation routines x86/copy_mc: Introduce copy_mc_enhanced_fast_string() x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() x86/mce: Drop AMD-specific "DEFERRED" case from Intel severity rule list x86/mce: Add Skylake quirk for patrol scrub reported errors RAS/CEC: Convert to DEFINE_SHOW_ATTRIBUTE() x86/mce: Annotate mce_rd/wrmsrl() with noinstr x86/mce/dev-mcelog: Do not update kflags on AMD systems x86/mce: Stop mce_reign() from re-computing severity for every CPU x86/mce: Make mce_rdmsrl() panic on an inaccessible MSR x86/mce: Increase maximum number of banks to 64 x86/mce: Delay clearing IA32_MCG_STATUS to the end of do_machine_check() x86/MCE/AMD, EDAC/mce_amd: Remove struct smca_hwid.xec_bitmap RAS/CEC: Fix cec_init() prototype
2020-10-06x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()Dan Williams
In reaction to a proposal to introduce a memcpy_mcsafe_fast() implementation Linus points out that memcpy_mcsafe() is poorly named relative to communicating the scope of the interface. Specifically what addresses are valid to pass as source, destination, and what faults / exceptions are handled. Of particular concern is that even though x86 might be able to handle the semantics of copy_mc_to_user() with its common copy_user_generic() implementation other archs likely need / want an explicit path for this case: On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds@linux-foundation.org> wrote: > > On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams@intel.com> wrote: > > > > However now I see that copy_user_generic() works for the wrong reason. > > It works because the exception on the source address due to poison > > looks no different than a write fault on the user address to the > > caller, it's still just a short copy. So it makes copy_to_user() work > > for the wrong reason relative to the name. > > Right. > > And it won't work that way on other architectures. On x86, we have a > generic function that can take faults on either side, and we use it > for both cases (and for the "in_user" case too), but that's an > artifact of the architecture oddity. > > In fact, it's probably wrong even on x86 - because it can hide bugs - > but writing those things is painful enough that everybody prefers > having just one function. Replace a single top-level memcpy_mcsafe() with either copy_mc_to_user(), or copy_mc_to_kernel(). Introduce an x86 copy_mc_fragile() name as the rename for the low-level x86 implementation formerly named memcpy_mcsafe(). It is used as the slow / careful backend that is supplanted by a fast copy_mc_generic() in a follow-on patch. One side-effect of this reorganization is that separating copy_mc_64.S to its own file means that perf no longer needs to track dependencies for its memcpy_64.S benchmarks. [ bp: Massage a bit. ] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: <stable@vger.kernel.org> Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com
2020-09-01dm writecache: handle DAX to partitions on persistent memory correctlyMikulas Patocka
The function dax_direct_access doesn't take partitions into account, it always maps pages from the beginning of the device. Therefore, persistent_memory_claim() must get the partition offset using get_start_sect() and add it to the page offsets passed to dax_direct_access(). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-08-07Merge tag 'powerpc-5.9-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Add support for (optionally) using queued spinlocks & rwlocks. - Support for a new faster system call ABI using the scv instruction on Power9 or later. - Drop support for the PROT_SAO mmap/mprotect flag as it will be unsupported on Power10 and future processors, leaving us with no way to implement the functionality it requests. This risks breaking userspace, though we believe it is unused in practice. - A bug fix for, and then the removal of, our custom stack expansion checking. We now allow stack expansion up to the rlimit, like other architectures. - Remove the remnants of our (previously disabled) topology update code, which tried to react to NUMA layout changes on virtualised systems, but was prone to crashes and other problems. - Add PMU support for Power10 CPUs. - A change to our signal trampoline so that we don't unbalance the link stack (branch return predictor) in the signal delivery path. - Lots of other cleanups, refactorings, smaller features and so on as usual. Thanks to: Abhishek Goel, Alastair D'Silva, Alexander A. Klimov, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Balamuruhan S, Bharata B Rao, Bill Wendling, Bin Meng, Cédric Le Goater, Chris Packham, Christophe Leroy, Christoph Hellwig, Daniel Axtens, Dan Williams, David Lamparter, Desnes A. Nunes do Rosario, Erhard F., Finn Thain, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geoff Levand, Greg Kurz, Gustavo A. R. Silva, Hari Bathini, Harish, Imre Kaloz, Joel Stanley, Joe Perches, John Crispin, Jordan Niethe, Kajol Jain, Kamalesh Babulal, Kees Cook, Laurent Dufour, Leonardo Bras, Li RongQing, Madhavan Srinivasan, Mahesh Salgaonkar, Mark Cave-Ayland, Michal Suchanek, Milton Miller, Mimi Zohar, Murilo Opsfelder Araujo, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nayna Jain, Nicholas Piggin, Oliver O'Halloran, Palmer Dabbelt, Pedro Miraglia Franco de Carvalho, Philippe Bergheaud, Pingfan Liu, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Randy Dunlap, Ravi Bangoria, Sachin Sant, Sam Bobroff, Sandipan Das, Santosh Sivaraj, Satheesh Rajendran, Shirisha Ganta, Sourabh Jain, Srikar Dronamraju, Stan Johnson, Stephen Rothwell, Thadeu Lima de Souza Cascardo, Thiago Jung Bauermann, Tom Lane, Vaibhav Jain, Vladis Dronov, Wei Yongjun, Wen Xiong, YueHaibing. * tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (337 commits) selftests/powerpc: Fix pkey syscall redefinitions powerpc: Fix circular dependency between percpu.h and mmu.h powerpc/powernv/sriov: Fix use of uninitialised variable selftests/powerpc: Skip vmx/vsx/tar/etc tests on older CPUs powerpc/40x: Fix assembler warning about r0 powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric powerpc/papr_scm: Fetch nvdimm performance stats from PHYP cpuidle: pseries: Fixup exit latency for CEDE(0) cpuidle: pseries: Add function to parse extended CEDE records cpuidle: pseries: Set the latency-hint before entering CEDE selftests/powerpc: Fix online CPU selection powerpc/perf: Consolidate perf_callchain_user_[64|32]() powerpc/pseries/hotplug-cpu: Remove double free in error path powerpc/pseries/mobility: Add pr_debug() for device tree changes powerpc/pseries/mobility: Set pr_fmt() powerpc/cacheinfo: Warn if cache object chain becomes unordered powerpc/cacheinfo: Improve diagnostics about malformed cache lists powerpc/cacheinfo: Use name@unit instead of full DT path in debug messages powerpc/cacheinfo: Set pr_fmt() powerpc: fix function annotations to avoid section mismatch warnings with gcc-10 ...
2020-08-04Merge tag 'uninit-macro-v5.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull uninitialized_var() macro removal from Kees Cook: "This is long overdue, and has hidden too many bugs over the years. The series has several "by hand" fixes, and then a trivial treewide replacement. - Clean up non-trivial uses of uninitialized_var() - Update documentation and checkpatch for uninitialized_var() removal - Treewide removal of uninitialized_var()" * tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: compiler: Remove uninitialized_var() macro treewide: Remove uninitialized_var() usage checkpatch: Remove awareness of uninitialized_var() macro mm/debug_vm_pgtable: Remove uninitialized_var() usage f2fs: Eliminate usage of uninitialized_var() macro media: sur40: Remove uninitialized_var() usage KVM: PPC: Book3S PR: Remove uninitialized_var() usage clk: spear: Remove uninitialized_var() usage clk: st: Remove uninitialized_var() usage spi: davinci: Remove uninitialized_var() usage ide: Remove uninitialized_var() usage rtlwifi: rtl8192cu: Remove uninitialized_var() usage b43: Remove uninitialized_var() usage drbd: Remove uninitialized_var() usage x86/mm/numa: Remove uninitialized_var() usage docs: deprecated.rst: Add uninitialized_var()
2020-08-03Merge tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: "Good amount of cleanups and tech debt removals in here, and as a result, the diffstat shows a nice net reduction in code. - Softirq completion cleanups (Christoph) - Stop using ->queuedata (Christoph) - Cleanup bd claiming (Christoph) - Use check_events, moving away from the legacy media change (Christoph) - Use inode i_blkbits consistently (Christoph) - Remove old unused writeback congestion bits (Christoph) - Cleanup/unify submission path (Christoph) - Use bio_uninit consistently, instead of bio_disassociate_blkg (Christoph) - sbitmap cleared bits handling (John) - Request merging blktrace event addition (Jan) - sysfs add/remove race fixes (Luis) - blk-mq tag fixes/optimizations (Ming) - Duplicate words in comments (Randy) - Flush deferral cleanup (Yufen) - IO context locking/retry fixes (John) - struct_size() usage (Gustavo) - blk-iocost fixes (Chengming) - blk-cgroup IO stats fixes (Boris) - Various little fixes" * tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block: (135 commits) block: blk-timeout: delete duplicated word block: blk-mq-sched: delete duplicated word block: blk-mq: delete duplicated word block: genhd: delete duplicated words block: elevator: delete duplicated word and fix typos block: bio: delete duplicated words block: bfq-iosched: fix duplicated word iocost_monitor: start from the oldest usage index iocost: Fix check condition of iocg abs_vdebt block: Remove callback typedefs for blk_mq_ops block: Use non _rcu version of list functions for tag_set_list blk-cgroup: show global disk stats in root cgroup io.stat blk-cgroup: make iostat functions visible to stat printing block: improve discard bio alignment in __blkdev_issue_discard() block: change REQ_OP_ZONE_RESET and REQ_OP_ZONE_RESET_ALL to be odd numbers block: defer flush request no matter whether we have elevator block: make blk_timeout_init() static block: remove retry loop in ioc_release_fn() block: remove unnecessary ioc nested locking block: integrate bd_start_claiming into __blkdev_get ...
2020-07-16treewide: Remove uninitialized_var() usageKees Cook
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-16libnvdimm/nvdimm/flush: Allow architecture to override the flush barrierAneesh Kumar K.V
Architectures like ppc64 provide persistent memory specific barriers that will ensure that all stores for which the modifications are written to persistent storage by preceding dcbfps and dcbstps instructions have updated persistent storage before any data access or data transfer caused by subsequent instructions is initiated. This is in addition to the ordering done by wmb() Update nvdimm core such that architecture can use barriers other than wmb to ensure all previous writes are architecturally visible for the platform buffer flush. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-5-aneesh.kumar@linux.ibm.com
2020-07-08dm writecache: reject asynchronous pmem devicesMichal Suchanek
DM writecache does not handle asynchronous pmem. Reject it when supplied as cache. Link: https://lore.kernel.org/linux-nvdimm/87lfk5hahc.fsf@linux.ibm.com/ Fixes: 6e84200c0a29 ("virtio-pmem: Add virtio pmem driver") Signed-off-by: Michal Suchanek <msuchanek@suse.de> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # 5.3+ Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-07-01block: rename generic_make_request to submit_bio_noacctChristoph Hellwig
generic_make_request has always been very confusingly misnamed, so rename it to submit_bio_noacct to make it clear that it is submit_bio minus accounting and a few checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-19dm writecache: add cond_resched to loop in persistent_memory_claim()Mikulas Patocka
Add cond_resched() to a loop that fills in the mapper memory area because the loop can be executed many times. Fixes: 48debafe4f2fe ("dm: add writecache target") Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-17dm writecache: skip writecache_wait when using pmem modeHuaisheng Ye
The array bio_in_progress is only used with ssd mode. So skip writecache_wait_for_ios in writecache_discard when pmem mode. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-17dm writecache: correct uncommitted_block when discarding uncommitted entryHuaisheng Ye
When uncommitted entry has been discarded, correct wc->uncommitted_block for getting the exact number. Fixes: 48debafe4f2fe ("dm: add writecache target") Cc: stable@vger.kernel.org Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-15dm writecache: improve performance on DDR persistent memory (Optane)Mikulas Patocka
When testing the dm-writecache target on a real DDR persistent memory (Intel Optane), it turned out that explicit cache flushing using the clflushopt instruction performs better than non-temporal stores for block sizes 1k, 2k and 4k. The dm-writecache target is singlethreaded (all the copying is done while holding the writecache lock), so it benefits from clwb, see: http://lore.kernel.org/r/alpine.LRH.2.02.2004160411460.7833@file01.intranet.prod.int.rdu2.redhat.com Add a new function memcpy_flushcache_optimized() that tests if clflushopt is present - and if it is, we use it instead of memcpy_flushcache. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-15dm writecache: remove superfluous test in persistent_memory_claimMikulas Patocka
Remove superfluous test if dax_dev is NULL - dax_direct_access already does this test. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-04-16dm writecache: fix data corruption when reloading the targetMikulas Patocka
The dm-writecache reads metadata in the target constructor. However, when we reload the target, there could be another active instance running on the same device. This is the sequence of operations when doing a reload: 1. construct new target 2. suspend old target 3. resume new target 4. destroy old target Metadata that were written by the old target between steps 1 and 2 would not be visible by the new target. Fix the data corruption by loading the metadata in the resume handler. Also, validate block_size is at least as large as both the devices' logical block size and only read 1 block from the metadata during target constructor -- no need to read entirety of metadata now that it is done during resume. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-27dm writecache: add cond_resched to avoid CPU hangsMikulas Patocka
Initializing a dm-writecache device can take a long time when the persistent memory device is large. Add cond_resched() to a few loops to avoid warnings that the CPU is stuck. Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-24dm writecache: optimize superblock writeMikulas Patocka
If we write a superblock in writecache_flush, we don't need to set bit and scan the bitmap for it - we can just write the superblock directly. Also, we can set the flag REQ_FUA on the write bio, so that we don't need to submit a flush bio afterwards. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-24dm writecache: implement gradual cleanupMikulas Patocka
If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-24dm writecache: implement the "cleaner" policyMikulas Patocka
The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-24dm writecache: do direct write if the cache is fullMikulas Patocka
If the cache device is full, we do a direct write to the origin device. Note that we must not do it if the written block is already in the cache. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-03dm: bump version of core and various targetsMike Snitzer
Changes made during the 5.6 cycle warrant bumping the version number for DM core and the targets modified by this commit. It should be noted that dm-thin, dm-crypt and dm-raid already had their target version bumped during the 5.6 merge window. Signed-off-by; Mike Snitzer <snitzer@redhat.com>
2020-02-27dm writecache: verify watermark during resumeMikulas Patocka
Verify the watermark upon resume - so that if the target is reloaded with lower watermark, it will start the cleanup process immediately. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-27dm: report suspended device during destroyMikulas Patocka
The function dm_suspended returns true if the target is suspended. However, when the target is being suspended during unload, it returns false. An example where this is a problem: the test "!dm_suspended(wc->ti)" in writecache_writeback is not sufficient, because dm_suspended returns zero while writecache_suspend is in progress. As is, without an enhanced dm_suspended, simply switching from flush_workqueue to drain_workqueue still emits warnings: workqueue writecache-writeback: drain_workqueue() isn't complete after 10 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 100 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 200 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 300 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 400 tries writecache_suspend calls flush_workqueue(wc->writeback_wq) - this function flushes the current work. However, the workqueue may re-queue itself and flush_workqueue doesn't wait for re-queued works to finish. Because of this - the function writecache_writeback continues execution after the device was suspended and then concurrently with writecache_dtr, causing a crash in writecache_writeback. We must use drain_workqueue - that waits until the work and all re-queued works finish. As a prereq for switching to drain_workqueue, this commit fixes dm_suspended to return true after the presuspend hook and before the postsuspend hook - just like during a normal suspend. It allows simplifying the dm-integrity and dm-writecache targets so that they don't have to maintain suspended flags on their own. With this change use of drain_workqueue() can be used effectively. This change was tested with the lvm2 testsuite and cryptsetup testsuite and the are no regressions. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Reported-by: Corey Marthaler <cmarthal@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-16dm writecache: improve performance of large linear writes on SSDsMikulas Patocka
When dm-writecache is used with SSD as a cache device, it would submit a separate bio for each written block. The I/Os would be merged by the disk scheduler, but this merging degrades performance. Improve dm-writecache performance by submitting larger bios - this is possible as long as there is consecutive free space on the cache device. Benchmark (arm64 with 64k page size, using /dev/ram0 as a cache device): fio --bs=512k --iodepth=32 --size=400M --direct=1 \ --filename=/dev/mapper/cache --rw=randwrite --numjobs=1 --name=test block old new size MiB/s MiB/s --------------------- 512 181 700 1k 347 1256 2k 644 2020 4k 1183 2759 8k 1852 3333 16k 2469 3509 32k 2974 3670 64k 3404 3810 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-14dm writecache: fix incorrect flush sequence when doing SSD mode commitMikulas Patocka
When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-11-05dm writecache: handle REQ_FUAMaged Mokhtar
Call writecache_flush() on REQ_FUA in writecache_map(). Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Maged Mokhtar <mmokhtar@petasan.org> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-11-05dm writecache: fix uninitialized variable warningMikulas Patocka
This fixes coverity warning CID 1454301. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-05dm writecache: skip writecache_wait for pmem modeHuaisheng Ye
The array bio_in_progress[2] only have chance to be increased and decreased with ssd mode. For pmem mode, they are not involved at all. So skip writecache_wait_for_ios in writecache_flush for pmem. Suggested-by: Doris Yu <tyu1@lenovo.com> Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26dm writecache: optimize performance by sorting the blocks for writeback_allHuaisheng Ye
During the process of writeback, the blocks, which have been placed in wbl.list for writeback soon, are partially ordered for the contiguous ones. When writeback_all has been set, for most cases, also by default, there will be a lot of blocks in pmem need to writeback at the same time. For this case, we could optimize the performance by sorting all blocks in wbl.list. writecache_writeback doesn't need to get blocks from the tail of wc->lru, whereas from the first rb_node from the rb_tree. The benefit is that, writecache_writeback doesn't need to have any cost to sort the blocks, because of all blocks are incremental originally in rb_tree. There will be a writecache_flush when writeback_all begins to work, that will eliminate duplicate blocks in cache by committed/uncommitted. Testing platform: Thinksystem SR630 with persistent memory. The cache comes from pmem, which has 1006MB size. The origin device is HDD, 2GB of which for using. Testing steps: 1) dmsetup create mycache --table '0 4194304 writecache p /dev/sdb1 /dev/pmem4 4096 0' 2) fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 3) time dmsetup message /dev/mapper/mycache 0 flush Here is the results below, With the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1582, max=199470, avg=5305.94, stdev=21273.44, samples=197 # time dmsetup message /dev/mapper/mycache 0 flush real 0m44.020s user 0m0.002s sys 0m0.003s Without the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1202, max=197650, avg=4968.67, stdev=20480.17, samples=211 # time dmsetup message /dev/mapper/mycache 0 flush real 1m39.221s user 0m0.001s sys 0m0.003s I also have checked the data accuracy with this patch by making EXT4 filesystem on mycache, then mount it for checking md5 of files on that. The test result is positive, with this patch it could save more than half of time when writeback_all. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26dm writecache: add unlikely for getting two block with same LBAHuaisheng Ye
In function writecache_writeback, entries g and f has same original sector only happens at entry f has been committed, but entry g has NOT yet. The probability of this happening is very low in the following 256 blocks at most of entry e. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26dm writecache: remove unused member pointer in writeback_structHuaisheng Ye
The stucture member pointer page in writeback_struct never has been used actually. Remove it. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-26dm writecache: avoid unnecessary lookups in writecache_find_entry()Mikulas Patocka
This is a small optimization in writecache_find_entry(). If we go past the condition "if (unlikely(!node))", we can be certain that there is no entry in the tree that has the block equal to the "block" variable. Consequently, we can return the next entry directly, we don't need to go to the second part of the function that finds the entry with lowest or highest seq number that matches the "block" variable. Also, add some whitespace and cleanup needless braces. Suggested-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-26dm writecache: remove unused member page_offset in writeback_structHuaisheng Ye
The stucture member page_offset in writeback_struct never has been used actually. Remove it. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-18dm writecache: add unlikely for returned value of rb_next/prevHuaisheng Ye
In functions writecache_discard() and writecache_find_entry() there is a high probablity that the pointer of structure rb_node won't equal NULL. Add unlikely for the pointer node NULL. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-18dm writecache: remove needless dereferences in __writecache_writeback_pmem()Huaisheng Ye
bio is already available so there is no need to access it in terms of the wb pointer. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-03-05dm writecache: fix typo in name for writeback_wqHuaisheng Ye
The workqueue's name should be "writecache-writeback" instead of "writecache-writeabck". Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-12-18dm writecache: fix typo in error msg for creating writecache_flush_threadShenghui Wang
The error msg should be "flush thread" instead of "endio thread" for writecache_flush_thread. Signed-off-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-10-22dm writecache: remove disabled code in memory_entry()Mike Snitzer
This dead branch was missed during review. It only makes memory_entry() more inefficient due to needless call to is_power_of_2(), etc. Reported-by: shenghui <shhuiw@foxmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-08-25Merge tag 'libnvdimm-for-4.19_misc' of ↵Linus Torvalds
gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dave Jiang: "Collection of misc libnvdimm patches for 4.19 submission: - Adding support to read locked nvdimm capacity. - Change test code to make DSM failure code injection an override. - Add support for calculate maximum contiguous area for namespace. - Add support for queueing a short ARS when there is on going ARS for nvdimm. - Allow NULL to be passed in to ->direct_access() for kaddr and pfn params. - Improve smart injection support for nvdimm emulation testing. - Fix test code that supports for emulating controller temperature. - Fix hang on error before devm_memremap_pages() - Fix a bug that causes user memory corruption when data returned to user for ars_status. - Maintainer updates for Ross Zwisler emails and adding Jan Kara to fsdax" * tag 'libnvdimm-for-4.19_misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm: fix ars_status output length calculation device-dax: avoid hang on error before devm_memremap_pages() tools/testing/nvdimm: improve emulation of smart injection filesystem-dax: Do not request kaddr and pfn when not required md/dm-writecache: Don't request pointer dummy_addr when not required dax/super: Do not request a pointer kaddr when not required tools/testing/nvdimm: kaddr and pfn can be NULL to ->direct_access() s390, dcssblk: kaddr and pfn can be NULL to ->direct_access() libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access() acpi/nfit: queue issuing of ars when an uc error notification comes in libnvdimm: Export max available extent libnvdimm: Use max contiguous area for namespace size MAINTAINERS: Add Jan Kara for filesystem DAX MAINTAINERS: update Ross Zwisler's email address tools/testing/nvdimm: Fix support for emulating controller temperature tools/testing/nvdimm: Make DSM failure code injection an override acpi, nfit: Prefer _DSM over _LSR for namespace label reads libnvdimm: Introduce locked DIMM capacity support
2018-08-16dm writecache: fix a crash due to reading past end of dirty_bitmapMikulas Patocka
wc->dirty_bitmap_size is in bytes so must multiply it by 8, not by BITS_PER_LONG, to get number of bitmap_bits. Fixes crash in find_next_bit() that was reported: https://bugzilla.kernel.org/show_bug.cgi?id=200819 Reported-by: edo.rus@gmail.com Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-07-30md/dm-writecache: Don't request pointer dummy_addr when not requiredHuaisheng Ye
Function persistent_memory_claim doesn't need to get local pointer dummy_addr from direct_access. Using NULL instead of having to pass in a useless local pointer that caller then just throw away. Suggested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-27dm writecache: report start_sector in status lineMikulas Patocka
Fixes: d284f8248c7 ("dm writecache: support optional offset for start of device") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-07-02dm writecache: support optional offset for start of deviceMikulas Patocka
Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-22dm writecache: use 2-factor allocator argumentsKees Cook
This adjusts the allocator calls to use the 2-factor argument style, as already done treewide for better defense against allocator overflows. Signed-off-by: Kees Cook <keescook@chromium.org> [snitzer: tweaked code to leave assignment in a test alone] Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-08dm: add writecache targetMikulas Patocka
The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>