kernel.git/drivers/dax/bus.c, branch linux-6.9.y

dax/bus.c: use the right locking mode (read vs write) in size_show

2024-05-30T07:44:59Z

[ Upstream commit 2acf04532d6d655d8c3b2ee4ddeb320107043086 ] In size_show(), the dax_dev_rwsem only needs a read lock, but was acquiring a write lock. Change it to down_read_interruptible() so it doesn't unnecessarily hold a write lock. Link: https://lkml.kernel.org/r/20240430-vv-dax_abi_fixes-v3-4-e3dcd755774c@intel.com Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem") Signed-off-by: Vishal Verma Reviewed-by: Dan Williams Cc: Alison Schofield Cc: Dave Jiang Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

dax/bus.c: don't use down_write_killable for non-user processes

2024-05-30T07:44:59Z

[ Upstream commit e39dbcfba714c4c2e924e96fc8fdde1080a5a737 ] Change an instance of down_write_killable() to a simple down_write() where there is no user process that might want to interrupt the operation. Link: https://lkml.kernel.org/r/20240430-vv-dax_abi_fixes-v3-3-e3dcd755774c@intel.com Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem") Signed-off-by: Vishal Verma Reported-by: Dan Williams Reviewed-by: Dan Williams Cc: Alison Schofield Cc: Dave Jiang Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

dax/bus.c: fix locking for unregister_dax_dev / unregister_dax_mapping paths

2024-05-30T07:44:59Z

[ Upstream commit 6f6544f27e41f9d7dca55c288f12175a9c48dfe2 ] Commit c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem") aimed to undo device_lock() abuses for protecting changes to dax-driver internal data-structures like the dax_region resource tree to device-dax-instance range structures. However, the device_lock() was legitimately enforcing that devices to be deleted were not current actively attached to any driver nor assigned any capacity from the region. As a result of the device_lock restoration in delete_store(), the conditional locking in unregister_dev_dax() and unregister_dax_mapping() can be removed. Link: https://lkml.kernel.org/r/20240430-vv-dax_abi_fixes-v3-2-e3dcd755774c@intel.com Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem") Signed-off-by: Vishal Verma Reported-by: Dan Williams Reviewed-by: Dan Williams Cc: Alison Schofield Cc: Dave Jiang Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

dax/bus.c: replace WARN_ON_ONCE() with lockdep asserts

2024-05-30T07:44:59Z

[ Upstream commit c14c647bbe23fd96f6bffcc122b9c6c8c46c7928 ] Patch series "dax/bus.c: Fixups for dax-bus locking", v3. Commit Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem") introduced a few problems that this series aims to fix. Add back device_lock() where it was correctly used (during device manipulation operations), remove conditional locking in unregister_dax_dev() and unregister_dax_mapping(), use non-interruptible versions of rwsem locks when not called from a user process, and fix up a write vs. read usage of an rwsem. This patch (of 4): In [1], Dan points out that all of the WARN_ON_ONCE() usage in the referenced patch should be replaced with lockdep_assert_held, or lockdep_held_assert_write(). Replace these as appropriate. Link: https://lkml.kernel.org/r/20240430-vv-dax_abi_fixes-v3-0-e3dcd755774c@intel.com Link: https://lore.kernel.org/r/65f0b5ef41817_aa222941a@dwillia2-mobl3.amr.corp.intel.com.notmuch [1] Link: https://lkml.kernel.org/r/20240430-vv-dax_abi_fixes-v3-1-e3dcd755774c@intel.com Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem") Signed-off-by: Vishal Verma Reported-by: Dan Williams Reviewed-by: Dan Williams Cc: Alison Schofield Cc: Dave Jiang Cc: Vishal Verma Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

Merge tag 'libnvdimm-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2024-03-15T18:58:32Z

Pull libnvdimm updates from Dave Jiang: - ACPI_NFIT Kconfig documetation fix - Make nvdimm_bus_type const - Make dax_bus_type const - remove SLAB_MEM_SPREAD flag usage in DAX * tag 'libnvdimm-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: remove SLAB_MEM_SPREAD flag usage device-dax: make dax_bus_type const nvdimm: make nvdimm_bus_type const libnvdimm: Fix ACPI_NFIT in BLK_DEV_PMEM help

dax: add a sysfs knob to control memmap_on_memory behavior

2024-02-22T18:24:40Z

Add a sysfs knob for dax devices to control the memmap_on_memory setting if the dax device were to be hotplugged as system memory. The default memmap_on_memory setting for dax devices originating via pmem or hmem is set to 'false' - i.e. no memmap_on_memory semantics, to preserve legacy behavior. For dax devices via CXL, the default is on. The sysfs control allows the administrator to override the above defaults if needed. Link: https://lkml.kernel.org/r/20240124-vv-dax_abi-v7-5-20d16cb8d23d@intel.com Signed-off-by: Vishal Verma Tested-by: Li Zhijian Reviewed-by: Jonathan Cameron Reviewed-by: David Hildenbrand Reviewed-by: Huang, Ying Reviewed-by: Alison Schofield Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Greg Kroah-Hartman Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Oscar Salvador Signed-off-by: Andrew Morton

dax/bus.c: replace several sprintf() with sysfs_emit()

2024-02-22T18:24:40Z

There were several places where drivers/dax/bus.c uses 'sprintf' to print sysfs data. Since a sysfs_emit() helper is available specifically for this purpose, replace all the sprintf() usage for sysfs with sysfs_emit() in this file. Link: https://lkml.kernel.org/r/20240124-vv-dax_abi-v7-2-20d16cb8d23d@intel.com Signed-off-by: Vishal Verma Reported-by: Greg Kroah-Hartman Reviewed-by: Alison Schofield Cc: Dan Williams Cc: Dave Hansen Cc: Dave Jiang Cc: David Hildenbrand Cc: Huang Ying Cc: Jonathan Cameron Cc: Li Zhijian Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Oscar Salvador Signed-off-by: Andrew Morton

dax/bus.c: replace driver-core lock usage by a local rwsem

2024-02-22T18:24:40Z

Patch series "Add DAX ABI for memmap_on_memory", v7. This series adds sysfs ABI to control memmap_on_memory behavior for DAX devices. Patch 1 replaces incorrect device_lock() usage with a local rwsem - this was identified during review. Patch 2 is also a preparatory patch that replaces sprintf() for sysfs operations with sysfs_emit() Patch 3 adds the missing documentation for the sysfs ABI for DAX regions and Dax devices. Patch 4 exports mhp_supports_memmap_on_memory(). Patch 5 adds the new ABI for toggling memmap_on_memory semantics for dax devices. This patch (of 5): The dax driver incorrectly used driver-core device locks to protect internal dax region and dax device configuration structures. Replace the device lock usage with a local rwsem, one each for dax region configuration and dax device configuration. As a result of this conversion, no device_lock() usage remains in dax/bus.c. Link: https://lkml.kernel.org/r/20240124-vv-dax_abi-v7-0-20d16cb8d23d@intel.com Link: https://lkml.kernel.org/r/20240124-vv-dax_abi-v7-1-20d16cb8d23d@intel.com Signed-off-by: Vishal Verma Reported-by: Greg Kroah-Hartman Reviewed-by: Alison Schofield Cc: Dan Williams Cc: Dave Hansen Cc: Dave Jiang Cc: David Hildenbrand Cc: Huang Ying Cc: Jonathan Cameron Cc: Li Zhijian Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Oscar Salvador Signed-off-by: Andrew Morton

device-dax: make dax_bus_type const

2024-02-12T22:10:21Z

Now that the driver core can properly handle constant struct bus_type, move the dax_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman Suggested-by: Greg Kroah-Hartman Signed-off-by: Ricardo B. Marliere Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20240204-bus_cleanup-dax-v1-1-69a6e4a8553b@marliere.net Signed-off-by: Dave Jiang

dax/kmem: allow kmem to add memory with memmap_on_memory

2023-12-11T00:51:35Z

Large amounts of memory managed by the kmem driver may come in via CXL, and it is often desirable to have the memmap for this memory on the new memory itself. Enroll kmem-managed memory for memmap_on_memory semantics if the dax region originates via CXL. For non-CXL dax regions, retain the existing default behavior of hot adding without memmap_on_memory semantics. Link: https://lkml.kernel.org/r/20231107-vv-kmem_memmap-v10-3-1253ec050ed0@intel.com Signed-off-by: Vishal Verma Reviewed-by: Jonathan Cameron Reviewed-by: David Hildenbrand Reviewed-by: "Huang, Ying" Tested-by: Li Zhijian [cxl.kmem and nvdimm.kmem] Cc: Michal Hocko Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Aneesh Kumar K.V Cc: Fan Ni Cc: Jeff Moyer Signed-off-by: Andrew Morton