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path: root/drivers/nvdimm/claim.c
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2018-06-28libnvdimm, pmem: Fix memcpy_mcsafe() return code handling in nsio_rw_bytes()Dan Williams
Commit 60622d68227d "x86/asm/memcpy_mcsafe: Return bytes remaining" converted callers of memcpy_mcsafe() to expect a positive 'bytes remaining' value rather than a negative error code. The nsio_rw_bytes() conversion failed to return success. The failure is benign in that nsio_rw_bytes() will end up writing back what it just read. Fixes: 60622d68227d ("x86/asm/memcpy_mcsafe: Return bytes remaining") Cc: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-05-15x86/asm/memcpy_mcsafe: Return bytes remainingDan Williams
Machine check safe memory copies are currently deployed in the pmem driver whenever reading from persistent memory media, so that -EIO is returned rather than triggering a kernel panic. While this protects most pmem accesses, it is not complete in the filesystem-dax case. When filesystem-dax is enabled reads may bypass the block layer and the driver via dax_iomap_actor() and its usage of copy_to_iter(). In preparation for creating a copy_to_iter() variant that can handle machine checks, teach memcpy_mcsafe() to return the number of bytes remaining rather than -EFAULT when an exception occurs. Co-developed-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539238119.31796.14318473522414462886.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-06libnvdimm: remove redundant __func__ in dev_dbgDan Williams
Dynamic debug can be instructed to add the function name to the debug output using the +f switch, so there is no need for the libnvdimm modules to do it again. If a user decides to add the +f switch for libnvdimm's dynamic debug this results in double prints of the function name. Reported-by: Johannes Thumshirn <jthumshirn@suse.de> Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-08-31libnvdimm, btt: rework error clearingVishal Verma
Clearing errors or badblocks during a BTT write requires sending an ACPI DSM, which means potentially sleeping. Since a BTT IO happens in atomic context (preemption disabled, spinlocks may be held), we cannot perform error clearing in the course of an IO. Due to this error clearing for BTT IOs has hitherto been disabled. In this patch we move error clearing out of the atomic section, and thus re-enable error clearing with BTTs. When we are about to add a block to the free list, we check if it was previously marked as an error, and if it was, we add it to the freelist, but also set a flag that says error clearing will be required. We then drop the lane (ending the atomic context), and send a zero buffer so that the error can be cleared. The error flag in the free list is protected by the nd 'lane', and is set only be a thread while it holds that lane. When the error is cleared, the flag is cleared, but while holding a mutex for that freelist index. When writing, we check for two things - 1/ If the freelist mutex is held or if the error flag is set. If so, this is an error block that is being (or about to be) cleared. 2/ If the block is a known badblock based on nsio->bb The second check is required because the BTT map error flag for a map entry only gets set when an error LBA is read. If we write to a new location that may not have the map error flag set, but still might be in the region's badblock list, we can trigger an EIO on the write, which is undesirable and completely avoidable. Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-08-31libnvdimm, btt: fix a missed NVDIMM_IO_ATOMIC case in the write pathVishal Verma
The IO context conversion for rw_bytes missed a case in the BTT write path (btt_map_write) which should've been marked as atomic. In reality this should not cause a problem, because map writes are to small for nsio_rw_bytes to attempt error clearing, but it should be fixed for posterity. Add a might_sleep() in the non-atomic section of nsio_rw_bytes so that things like the nfit unit tests, which don't actually sleep, can catch bugs like this. Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-07-03Merge branch 'for-4.13/dax' into libnvdimm-for-nextDan Williams
2017-06-30libnvdimm: fix the clear-error check in nsio_rw_bytesVishal Verma
A leftover from the 'bandaid' fix that disabled BTT error clearing in rw_bytes resulted in an incorrect check. After we converted these checks over to use the NVDIMM_IO_ATOMIC flag, the ndns->claim check was both redundant, and incorrect. Remove it. Fixes: 3ae3d67ba705 ("libnvdimm: add an atomic vs process context flag to rw_bytes") Cc: <stable@vger.kernel.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-29libnvdimm, btt: BTT updates for UEFI 2.7 formatVishal Verma
The UEFI 2.7 specification defines an updated BTT metadata format, bumping the revision to 2.0. Add support for the new format, while retaining compatibility for the old 1.1 format. Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Linda Knippers <linda.knippers@hpe.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-27x86, libnvdimm, pmem: remove global pmem apiDan Williams
Now that all callers of the pmem api have been converted to dax helpers that call back to the pmem driver, we can remove include/linux/pmem.h and asm/pmem.h. Cc: <x86@kernel.org> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Oliver O'Halloran <oohall@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-27x86, libnvdimm, pmem: move arch_invalidate_pmem() to libnvdimmDan Williams
Kill this globally defined wrapper and move to libnvdimm so that we can ultimately remove include/linux/pmem.h and asm/pmem.h. Cc: <x86@kernel.org> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-15libnvdimm, label: add address abstraction identifiersDan Williams
Starting with v1.2 labels, 'address abstractions' can be hinted via an address abstraction id that implies an info-block format. The standard address abstraction in the specification is the v2 format of the Block-Translation-Table (BTT). Support for that is saved for a later patch, for now we add support for the Linux supported address abstractions BTT (v1), PFN, and DAX. The new 'holder_class' attribute for namespace devices is added for tooling to specify the 'abstraction_guid' to store in the namespace label. For v1.1 labels this field is undefined and any setting of 'holder_class' away from the default 'none' value will only have effect until the driver is unloaded. Setting 'holder_class' requires that whatever device tries to claim the namespace must be of the specified class. Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-09x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass ↵Dan Williams
operations The pmem driver has a need to transfer data with a persistent memory destination and be able to rely on the fact that the destination writes are not cached. It is sufficient for the writes to be flushed to a cpu-store-buffer (non-temporal / "movnt" in x86 terms), as we expect userspace to call fsync() to ensure data-writes have reached a power-fail-safe zone in the platform. The fsync() triggers a REQ_FUA or REQ_FLUSH to the pmem driver which will turn around and fence previous writes with an "sfence". Implement a __copy_from_user_inatomic_flushcache, memcpy_page_flushcache, and memcpy_flushcache, that guarantee that the destination buffer is not dirty in the cpu cache on completion. The new copy_from_iter_flushcache and sub-routines will be used to replace the "pmem api" (include/linux/pmem.h + arch/x86/include/asm/pmem.h). The availability of copy_from_iter_flushcache() and memcpy_flushcache() are gated by the CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE config symbol, and fallback to copy_from_iter_nocache() and plain memcpy() otherwise. This is meant to satisfy the concern from Linus that if a driver wants to do something beyond the normal nocache semantics it should be something private to that driver [1], and Al's concern that anything uaccess related belongs with the rest of the uaccess code [2]. The first consumer of this interface is a new 'copy_from_iter' dax operation so that pmem can inject cache maintenance operations without imposing this overhead on other dax-capable drivers. [1]: https://lists.01.org/pipermail/linux-nvdimm/2017-January/008364.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2017-April/009942.html Cc: <x86@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-10libnvdimm: add an atomic vs process context flag to rw_bytesVishal Verma
nsio_rw_bytes can clear media errors, but this cannot be done while we are in an atomic context due to locking within ACPI. From the BTT, ->rw_bytes may be called either from atomic or process context depending on whether the calls happen during initialization or during IO. During init, we want to ensure error clearing happens, and the flag marking process context allows nsio_rw_bytes to do that. When called during IO, we're in atomic context, and error clearing can be skipped. Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-04Merge branch 'for-4.12/dax' into libnvdimm-for-nextDan Williams
2017-05-01libnvdimm: restore "libnvdimm: band aid btt vs clear poison locking"Dan Williams
This continues the 4.11 status quo of disabling of error clearing from the BTT I/O path. Toshi found that even though we have eliminated all the libnvdimm sources of sleeping-while-atomic triggers, we still have sleeping operations that will occur in the path to send the ACPI DSM to the DIMM to clear the error: BUG: sleeping function called from invalid context at mm/slab.h:432 in_atomic(): 1, irqs_disabled(): 0, pid: 13353, name: dd Call Trace: dump_stack+0x86/0xc3 ___might_sleep+0x17d/0x250 __might_sleep+0x4a/0x80 __kmalloc+0x1c0/0x2e0 acpi_os_allocate_zeroed+0x2d/0x2f acpi_evaluate_object+0x59/0x3b1 acpi_evaluate_dsm+0xbd/0x10c acpi_nfit_ctl+0x1ef/0x7c0 [nfit] ? nsio_rw_bytes+0x152/0x280 nvdimm_clear_poison+0x77/0x140 nsio_rw_bytes+0x18f/0x280 btt_write_pg+0x1d4/0x3d0 [nd_btt] btt_make_request+0x119/0x2d0 [nd_btt] A solution for tracking and handling media errors natively in the BTT is needed. Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Reported-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-01libnvdimm: fix nvdimm_bus_lock() vs device_lock() orderingDan Williams
A debug patch to turn the standard device_lock() into something that lockdep can analyze yielded the following: ====================================================== [ INFO: possible circular locking dependency detected ] 4.11.0-rc4+ #106 Tainted: G O ------------------------------------------------------- lt-libndctl/1898 is trying to acquire lock: (&dev->nvdimm_mutex/3){+.+.+.}, at: [<ffffffffc023c948>] nd_attach_ndns+0x178/0x1b0 [libnvdimm] but task is already holding lock: (&nvdimm_bus->reconfig_mutex){+.+.+.}, at: [<ffffffffc022e0b1>] nvdimm_bus_lock+0x21/0x30 [libnvdimm] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&nvdimm_bus->reconfig_mutex){+.+.+.}: lock_acquire+0xf6/0x1f0 __mutex_lock+0x88/0x980 mutex_lock_nested+0x1b/0x20 nvdimm_bus_lock+0x21/0x30 [libnvdimm] nvdimm_namespace_capacity+0x1b/0x40 [libnvdimm] nvdimm_namespace_common_probe+0x230/0x510 [libnvdimm] nd_pmem_probe+0x14/0x180 [nd_pmem] nvdimm_bus_probe+0xa9/0x260 [libnvdimm] -> #0 (&dev->nvdimm_mutex/3){+.+.+.}: __lock_acquire+0x1107/0x1280 lock_acquire+0xf6/0x1f0 __mutex_lock+0x88/0x980 mutex_lock_nested+0x1b/0x20 nd_attach_ndns+0x178/0x1b0 [libnvdimm] nd_namespace_store+0x308/0x3c0 [libnvdimm] namespace_store+0x87/0x220 [libnvdimm] In this case '&dev->nvdimm_mutex/3' mirrors '&dev->mutex'. Fix this by replacing the use of device_lock() with nvdimm_bus_lock() to protect nd_{attach,detach}_ndns() operations. Cc: <stable@vger.kernel.org> Fixes: 8c2f7e8658df ("libnvdimm: infrastructure for btt devices") Reported-by: Yi Zhang <yizhan@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-27libnvdimm: fix phys_addr for nvdimm_clear_poisonToshi Kani
nvdimm_clear_poison() expects a physical address, not an offset. Fix nsio_rw_bytes() to call nvdimm_clear_poison() with a physical address. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-25x86, dax, pmem: remove indirection around memcpy_from_pmem()Dan Williams
memcpy_from_pmem() maps directly to memcpy_mcsafe(). The wrapper serves no real benefit aside from affording a more generic function name than the x86-specific 'mcsafe'. However this would not be the first time that x86 terminology leaked into the global namespace. For lack of better name, just use memcpy_mcsafe() directly. This conversion also catches a place where we should have been using plain memcpy, acpi_nfit_blk_single_io(). Cc: <x86@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-14Revert "libnvdimm: band aid btt vs clear poison locking"Dan Williams
This reverts commit 4aa5615e080a "libnvdimm: band aid btt vs clear poison locking". Now that poison list locking has been converted to a spinlock and poison list entry allocation during i/o has been converted to GFP_NOWAIT, revert the band-aid that disabled error clearing from btt i/o. Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-10libnvdimm: band aid btt vs clear poison lockingDan Williams
The following warning results from holding a lane spinlock, preempt_disable(), or the btt map spinlock and then trying to take the reconfig_mutex to walk the poison list and potentially add new entries. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747 in_atomic(): 1, irqs_disabled(): 0, pid: 17159, name: dd [..] Call Trace: dump_stack+0x85/0xc8 ___might_sleep+0x184/0x250 __might_sleep+0x4a/0x90 __mutex_lock+0x58/0x9b0 ? nvdimm_bus_lock+0x21/0x30 [libnvdimm] ? __nvdimm_bus_badblocks_clear+0x2f/0x60 [libnvdimm] ? acpi_nfit_forget_poison+0x79/0x80 [nfit] ? _raw_spin_unlock+0x27/0x40 mutex_lock_nested+0x1b/0x20 nvdimm_bus_lock+0x21/0x30 [libnvdimm] nvdimm_forget_poison+0x25/0x50 [libnvdimm] nvdimm_clear_poison+0x106/0x140 [libnvdimm] nsio_rw_bytes+0x164/0x270 [libnvdimm] btt_write_pg+0x1de/0x3e0 [nd_btt] ? blk_queue_enter+0x30/0x290 btt_make_request+0x11a/0x310 [nd_btt] ? blk_queue_enter+0xb7/0x290 ? blk_queue_enter+0x30/0x290 generic_make_request+0x118/0x3b0 As a minimal fix, disable error clearing when the BTT is enabled for the namespace. For the final fix a larger rework of the poison list locking is needed. Note that this is not a problem in the blk case since that path never calls nvdimm_clear_poison(). Cc: <stable@vger.kernel.org> Fixes: 82bf1037f2ca ("libnvdimm: check and clear poison before writing to pmem") Cc: Dave Jiang <dave.jiang@intel.com> [jeff: dynamically disable error clearing in the btt case] Suggested-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Reported-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-12-16libnvdimm: fix mishandled nvdimm_clear_poison() return valueDan Williams
Colin, via static analysis, reports that the length could be negative from nvdimm_clear_poison() in the error case. There was a similar problem with commit 0a3f27b9a6a8 "libnvdimm, namespace: avoid multiple sector calculations" that I noticed when merging the for-4.10/libnvdimm topic branch into libnvdimm-for-next, but I missed this one. Fix both of them to the following procedure: * if we clear a block's worth of media, clear that many blocks in badblocks * if we clear less than the requested size of the transfer return an error * always invalidate cache after any non-error / non-zero nvdimm_clear_poison result Fixes: 82bf1037f2ca ("libnvdimm: check and clear poison before writing to pmem") Fixes: 0a3f27b9a6a8 ("libnvdimm, namespace: avoid multiple sector calculations") Cc: Fabian Frederick <fabf@skynet.be> Cc: Dave Jiang <dave.jiang@intel.com> Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-12-15libnvdimm: replace mutex_is_locked() warnings with lockdep_assert_heldDan Williams
For warnings that should only ever trigger during development and testing replace WARN statements with lockdep_assert_held. The lockdep pattern is prevalent, and these paths are are well covered by libnvdimm unit tests. Reported-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-12-04libnvdimm: remove else after return in nsio_rw_bytes()Fabian Frederick
else after return is not needed. Signed-off-by: Fabian Frederick <fabf@skynet.be> [djbw: removed some now unnecessary newlines] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-11-28libnvdimm: use consistent naming for request_mem_region()Dan Williams
Here is an example /proc/iomem listing for a system with 2 namespaces, one in "sector" mode and one in "memory" mode: 1fc000000-2fbffffff : Persistent Memory (legacy) 1fc000000-2fbffffff : namespace1.0 340000000-34fffffff : Persistent Memory 340000000-34fffffff : btt0.1 Here is the corresponding ndctl listing: # ndctl list [ { "dev":"namespace1.0", "mode":"memory", "size":4294967296, "blockdev":"pmem1" }, { "dev":"namespace0.0", "mode":"sector", "size":267091968, "uuid":"f7594f86-badb-4592-875f-ded577da2eaf", "sector_size":4096, "blockdev":"pmem0s" } ] Notice that the ndctl listing is purely in terms of namespace devices, while the iomem listing leaks the internal "btt0.1" implementation detail. Given that ndctl requires the namespace device name to change the mode, for example: # ndctl create-namespace --reconfig=namespace0.0 --mode=raw --force ...use the namespace name in the iomem listing to keep the claiming device name consistent across different mode settings. Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-11-11libnvdimm: check and clear poison before writing to pmemDave Jiang
We need to clear any poison when we are writing to pmem. The granularity will be sector size. If it's less then we can't do anything about it barring corruption. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> [djbw: fixup 0-length write request to succeed] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-07-12libnvdimm, pmem: use nvdimm_flush() for namespace I/O writesDan Williams
nsio_rw_bytes() is used to write info block metadata to the namespace, so it should trigger a flush after every write. Replace wmb_pmem() with nvdimm_flush() in this path. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-17libnvdimm: IS_ERR() usage cleanupDan Williams
Prompted by commit 287980e49ffc "remove lots of IS_ERR_VALUE abuses", I ran make coccicheck against drivers/nvdimm/ and found that: if (IS_ERR(x)) return PTR_ERR(x); return 0; ...can be replaced with PTR_ERR_OR_ZERO(). Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-21libnvdimm, dax: fix deletionDan Williams
The ndctl unit tests discovered that the dax enabling omitted updates to nd_detach_and_reset(). This routine clears device the configuration when the namespace is detached. Without this clearing userspace may assume that the device is in the process of being configured by another agent in the system. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-09libnvdimm, dax: introduce device-dax infrastructureDan Williams
Device DAX is the device-centric analogue of Filesystem DAX (CONFIG_FS_DAX). It allows persistent memory ranges to be allocated and mapped without need of an intervening file system. This initial infrastructure arranges for a libnvdimm pfn-device to be represented as a different device-type so that it can be attached to a driver other than the pmem driver. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-04-22libnvdimm, pmem, pfn: make pmem_rw_bytes generic and refactor pfn setupDan Williams
In preparation for providing an alternative (to block device) access mechanism to persistent memory, convert pmem_rw_bytes() to nsio_rw_bytes(). This allows ->rw_bytes() functionality without requiring a 'struct pmem_device' to be instantiated. In other words, when ->rw_bytes() is in use i/o is driven through 'struct nd_namespace_io', otherwise it is driven through 'struct pmem_device' and the block layer. This consolidates the disjoint calls to devm_exit_badblocks() and devm_memunmap() into a common devm_nsio_disable() and cleans up the init path to use a unified pmem_attach_disk() implementation. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-08-28libnvdimm, pfn: 'struct page' provider infrastructureDan Williams
Implement the base infrastructure for libnvdimm PFN devices. Similar to BTT devices they take a namespace as a backing device and layer functionality on top. In this case the functionality is reserving space for an array of 'struct page' entries to be handed out through pfn_to_page(). For now this is just the basic libnvdimm-device-model for configuring the base PFN device. As the namespace claiming mechanism for PFN devices is mostly identical to BTT devices drivers/nvdimm/claim.c is created to house the common bits. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>