7d3bf613e9
Pull libnvdimm updates from Dan Williams:
"This adds a user for the new 'bytes-remaining' updates to
memcpy_mcsafe() that you already received through Ingo via the
x86-dax- for-linus pull.
Not included here, but still targeting this cycle, is support for
handling memory media errors (poison) consumed via userspace dax
mappings.
Summary:
- DAX broke a fundamental assumption of truncate of file mapped
pages. The truncate path assumed that it is safe to disconnect a
pinned page from a file and let the filesystem reclaim the physical
block. With DAX the page is equivalent to the filesystem block.
Introduce dax_layout_busy_page() to enable filesystems to wait for
pinned DAX pages to be released. Without this wait a filesystem
could allocate blocks under active device-DMA to a new file.
- DAX arranges for the block layer to be bypassed and uses
dax_direct_access() + copy_to_iter() to satisfy read(2) calls.
However, the memcpy_mcsafe() facility is available through the pmem
block driver. In order to safely handle media errors, via the DAX
block-layer bypass, introduce copy_to_iter_mcsafe().
- Fix cache management policy relative to the ACPI NFIT Platform
Capabilities Structure to properly elide cache flushes when they
are not necessary. The table indicates whether CPU caches are
power-fail protected. Clarify that a deep flush is always performed
on REQ_{FUA,PREFLUSH} requests"
* tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits)
dax: Use dax_write_cache* helpers
libnvdimm, pmem: Do not flush power-fail protected CPU caches
libnvdimm, pmem: Unconditionally deep flush on *sync
libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH
acpi, nfit: Remove ecc_unit_size
dax: dax_insert_mapping_entry always succeeds
libnvdimm, e820: Register all pmem resources
libnvdimm: Debug probe times
linvdimm, pmem: Preserve read-only setting for pmem devices
x86, nfit_test: Add unit test for memcpy_mcsafe()
pmem: Switch to copy_to_iter_mcsafe()
dax: Report bytes remaining in dax_iomap_actor()
dax: Introduce a ->copy_to_iter dax operation
uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation
xfs, dax: introduce xfs_break_dax_layouts()
xfs: prepare xfs_break_layouts() for another layout type
xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL
mm, fs, dax: handle layout changes to pinned dax mappings
mm: fix __gup_device_huge vs unmap
mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS
...
165 lines
4.7 KiB
C
165 lines
4.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_DAX_H
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#define _LINUX_DAX_H
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/radix-tree.h>
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#include <asm/pgtable.h>
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struct iomap_ops;
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struct dax_device;
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struct dax_operations {
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/*
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* direct_access: translate a device-relative
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* logical-page-offset into an absolute physical pfn. Return the
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* number of pages available for DAX at that pfn.
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*/
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long (*direct_access)(struct dax_device *, pgoff_t, long,
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void **, pfn_t *);
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/* copy_from_iter: required operation for fs-dax direct-i/o */
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size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t,
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struct iov_iter *);
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/* copy_to_iter: required operation for fs-dax direct-i/o */
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size_t (*copy_to_iter)(struct dax_device *, pgoff_t, void *, size_t,
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struct iov_iter *);
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};
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extern struct attribute_group dax_attribute_group;
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#if IS_ENABLED(CONFIG_DAX)
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struct dax_device *dax_get_by_host(const char *host);
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struct dax_device *alloc_dax(void *private, const char *host,
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const struct dax_operations *ops);
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void put_dax(struct dax_device *dax_dev);
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void kill_dax(struct dax_device *dax_dev);
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void dax_write_cache(struct dax_device *dax_dev, bool wc);
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bool dax_write_cache_enabled(struct dax_device *dax_dev);
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#else
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static inline struct dax_device *dax_get_by_host(const char *host)
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{
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return NULL;
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}
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static inline struct dax_device *alloc_dax(void *private, const char *host,
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const struct dax_operations *ops)
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{
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/*
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* Callers should check IS_ENABLED(CONFIG_DAX) to know if this
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* NULL is an error or expected.
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*/
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return NULL;
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}
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static inline void put_dax(struct dax_device *dax_dev)
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{
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}
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static inline void kill_dax(struct dax_device *dax_dev)
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{
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}
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static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
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{
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}
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static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
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{
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return false;
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}
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#endif
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struct writeback_control;
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int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
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#if IS_ENABLED(CONFIG_FS_DAX)
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bool __bdev_dax_supported(struct block_device *bdev, int blocksize);
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static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize)
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{
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return __bdev_dax_supported(bdev, blocksize);
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}
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static inline struct dax_device *fs_dax_get_by_host(const char *host)
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{
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return dax_get_by_host(host);
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}
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static inline void fs_put_dax(struct dax_device *dax_dev)
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{
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put_dax(dax_dev);
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}
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struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev);
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int dax_writeback_mapping_range(struct address_space *mapping,
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struct block_device *bdev, struct writeback_control *wbc);
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struct page *dax_layout_busy_page(struct address_space *mapping);
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#else
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static inline bool bdev_dax_supported(struct block_device *bdev,
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int blocksize)
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{
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return false;
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}
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static inline struct dax_device *fs_dax_get_by_host(const char *host)
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{
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return NULL;
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}
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static inline void fs_put_dax(struct dax_device *dax_dev)
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{
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}
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static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
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{
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return NULL;
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}
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static inline struct page *dax_layout_busy_page(struct address_space *mapping)
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{
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return NULL;
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}
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static inline int dax_writeback_mapping_range(struct address_space *mapping,
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struct block_device *bdev, struct writeback_control *wbc)
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{
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return -EOPNOTSUPP;
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}
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#endif
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int dax_read_lock(void);
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void dax_read_unlock(int id);
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bool dax_alive(struct dax_device *dax_dev);
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void *dax_get_private(struct dax_device *dax_dev);
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long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
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void **kaddr, pfn_t *pfn);
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size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
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size_t bytes, struct iov_iter *i);
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size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
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size_t bytes, struct iov_iter *i);
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void dax_flush(struct dax_device *dax_dev, void *addr, size_t size);
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ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
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const struct iomap_ops *ops);
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int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
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pfn_t *pfnp, int *errp, const struct iomap_ops *ops);
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vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
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enum page_entry_size pe_size, pfn_t pfn);
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int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
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int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
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pgoff_t index);
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#ifdef CONFIG_FS_DAX
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int __dax_zero_page_range(struct block_device *bdev,
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struct dax_device *dax_dev, sector_t sector,
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unsigned int offset, unsigned int length);
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#else
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static inline int __dax_zero_page_range(struct block_device *bdev,
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struct dax_device *dax_dev, sector_t sector,
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unsigned int offset, unsigned int length)
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{
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return -ENXIO;
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}
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#endif
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static inline bool dax_mapping(struct address_space *mapping)
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{
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return mapping->host && IS_DAX(mapping->host);
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}
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#endif
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