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authorLinus Torvalds <torvalds@linux-foundation.org>2018-06-08 17:21:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-08 17:21:52 -0700
commit7d3bf613e99abbd96ac7b90ee3694a246c975021 (patch)
tree084e4d900025ce3459702d3a8c05ead860c67c64 /drivers/dax
parenta3818841bd5e9b4a7e0e732c19cf3a632fcb525e (diff)
parent930218affeadd1325ea17e053f0dcecf218f5a4f (diff)
Merge tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
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 ...
Diffstat (limited to 'drivers/dax')
-rw-r--r--drivers/dax/super.c33
1 files changed, 24 insertions, 9 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 1d7bd96511f0..903d9c473749 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -85,6 +85,7 @@ EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev);
bool __bdev_dax_supported(struct block_device *bdev, int blocksize)
{
struct dax_device *dax_dev;
+ bool dax_enabled = false;
pgoff_t pgoff;
int err, id;
void *kaddr;
@@ -134,14 +135,21 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize)
* on being able to do (page_address(pfn_to_page())).
*/
WARN_ON(IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API));
+ dax_enabled = true;
} else if (pfn_t_devmap(pfn)) {
- /* pass */;
- } else {
+ struct dev_pagemap *pgmap;
+
+ pgmap = get_dev_pagemap(pfn_t_to_pfn(pfn), NULL);
+ if (pgmap && pgmap->type == MEMORY_DEVICE_FS_DAX)
+ dax_enabled = true;
+ put_dev_pagemap(pgmap);
+ }
+
+ if (!dax_enabled) {
pr_debug("%s: error: dax support not enabled\n",
bdevname(bdev, buf));
return false;
}
-
return true;
}
EXPORT_SYMBOL_GPL(__bdev_dax_supported);
@@ -182,8 +190,7 @@ static ssize_t write_cache_show(struct device *dev,
if (!dax_dev)
return -ENXIO;
- rc = sprintf(buf, "%d\n", !!test_bit(DAXDEV_WRITE_CACHE,
- &dax_dev->flags));
+ rc = sprintf(buf, "%d\n", !!dax_write_cache_enabled(dax_dev));
put_dax(dax_dev);
return rc;
}
@@ -201,10 +208,8 @@ static ssize_t write_cache_store(struct device *dev,
if (rc)
len = rc;
- else if (write_cache)
- set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
else
- clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
+ dax_write_cache(dax_dev, write_cache);
put_dax(dax_dev);
return len;
@@ -282,11 +287,21 @@ size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
}
EXPORT_SYMBOL_GPL(dax_copy_from_iter);
+size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
+ size_t bytes, struct iov_iter *i)
+{
+ if (!dax_alive(dax_dev))
+ return 0;
+
+ return dax_dev->ops->copy_to_iter(dax_dev, pgoff, addr, bytes, i);
+}
+EXPORT_SYMBOL_GPL(dax_copy_to_iter);
+
#ifdef CONFIG_ARCH_HAS_PMEM_API
void arch_wb_cache_pmem(void *addr, size_t size);
void dax_flush(struct dax_device *dax_dev, void *addr, size_t size)
{
- if (unlikely(!test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags)))
+ if (unlikely(!dax_write_cache_enabled(dax_dev)))
return;
arch_wb_cache_pmem(addr, size);