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Commit d5ff0814 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 

Pull nvdimm fixes from Dan Williams:
 "A small crop of lockdep, sleeping while atomic, and other fixes /
  band-aids in advance of the full-blown reworks targeting the next
  merge window. The largest change here is "libnvdimm: fix blk free
  space accounting" which deletes a pile of buggy code that better
  testing would have caught before merging. The next change that is
  borderline too big for a late rc is switching the device-dax locking
  from rcu to srcu, I couldn't think of a smaller way to make that fix.

  The __copy_user_nocache fix will have a full replacement in 4.12 to
  move those pmem special case considerations into the pmem driver. The
  "libnvdimm: band aid btt vs clear poison locking" commit admits that
  our error clearing support for btt went in broken, so we just disable
  it in 4.11 and -stable. A replacement / full fix is in the pipeline
  for 4.12

  Some of these would have been caught earlier had DEBUG_ATOMIC_SLEEP
  been enabled on my development station. I wonder if we should have:

      config DEBUG_ATOMIC_SLEEP
        default PROVE_LOCKING

  ...since I mistakenly thought I got both with PROVE_LOCKING=y.

  These have received a build success notification from the 0day robot,
  and some have appeared in a -next release with no reported issues"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  x86, pmem: fix broken __copy_user_nocache cache-bypass assumptions
  device-dax: switch to srcu, fix rcu_read_lock() vs pte allocation
  libnvdimm: band aid btt vs clear poison locking
  libnvdimm: fix reconfig_mutex, mmap_sem, and jbd2_handle lockdep splat
  libnvdimm: fix blk free space accounting
  acpi, nfit, libnvdimm: fix interleave set cookie calculation (64-bit comparison)
parents 403a39f8 11e63f6d

arch/x86/include/asm/pmem.h

+31 −11
Original line number Diff line number Diff line
@@ -55,7 +55,8 @@ static inline int arch_memcpy_from_pmem(void *dst, const void *src, size_t n) 
 * @size:	number of bytes to write back

 *

 * Write back a cache range using the CLWB (cache line write back)

 * instruction.

 * instruction. Note that @size is internally rounded up to be cache

 * line size aligned.

 */

static inline void arch_wb_cache_pmem(void *addr, size_t size)

{
@@ -69,15 +70,6 @@ static inline void arch_wb_cache_pmem(void *addr, size_t size) 
		clwb(p);

}



/*

 * copy_from_iter_nocache() on x86 only uses non-temporal stores for iovec

 * iterators, so for other types (bvec & kvec) we must do a cache write-back.

 */

static inline bool __iter_needs_pmem_wb(struct iov_iter *i)

{

	return iter_is_iovec(i) == false;

}



/**

 * arch_copy_from_iter_pmem - copy data from an iterator to PMEM

 * @addr:	PMEM destination address
@@ -94,7 +86,35 @@ static inline size_t arch_copy_from_iter_pmem(void *addr, size_t bytes, 
	/* TODO: skip the write-back by always using non-temporal stores */

	len = copy_from_iter_nocache(addr, bytes, i);



	if (__iter_needs_pmem_wb(i))

	/*

	 * In the iovec case on x86_64 copy_from_iter_nocache() uses

	 * non-temporal stores for the bulk of the transfer, but we need

	 * to manually flush if the transfer is unaligned. A cached

	 * memory copy is used when destination or size is not naturally

	 * aligned. That is:

	 *   - Require 8-byte alignment when size is 8 bytes or larger.

	 *   - Require 4-byte alignment when size is 4 bytes.

	 *

	 * In the non-iovec case the entire destination needs to be

	 * flushed.

	 */

	if (iter_is_iovec(i)) {

		unsigned long flushed, dest = (unsigned long) addr;



		if (bytes < 8) {

			if (!IS_ALIGNED(dest, 4) || (bytes != 4))

				arch_wb_cache_pmem(addr, 1);

		} else {

			if (!IS_ALIGNED(dest, 8)) {

				dest = ALIGN(dest, boot_cpu_data.x86_clflush_size);

				arch_wb_cache_pmem(addr, 1);

			}



			flushed = dest - (unsigned long) addr;

			if (bytes > flushed && !IS_ALIGNED(bytes - flushed, 8))

				arch_wb_cache_pmem(addr + bytes - 1, 1);

		}

	} else

		arch_wb_cache_pmem(addr, bytes);



	return len;

drivers/acpi/nfit/core.c

+5 −1
Original line number Diff line number Diff line
@@ -1617,7 +1617,11 @@ static int cmp_map(const void *m0, const void *m1) 
	const struct nfit_set_info_map *map0 = m0;

	const struct nfit_set_info_map *map1 = m1;



	return map0->region_offset - map1->region_offset;

	if (map0->region_offset < map1->region_offset)

		return -1;

	else if (map0->region_offset > map1->region_offset)

		return 1;

	return 0;

}



/* Retrieve the nth entry referencing this spa */

drivers/dax/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ menuconfig DEV_DAX 
	tristate "DAX: direct access to differentiated memory"

	default m if NVDIMM_DAX

	depends on TRANSPARENT_HUGEPAGE

	select SRCU

	help

	  Support raw access to differentiated (persistence, bandwidth,

	  latency...) memory via an mmap(2) capable character

drivers/dax/dax.c

+7 −6
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include "dax.h"



static dev_t dax_devt;

DEFINE_STATIC_SRCU(dax_srcu);

static struct class *dax_class;

static DEFINE_IDA(dax_minor_ida);

static int nr_dax = CONFIG_NR_DEV_DAX;
@@ -60,7 +61,7 @@ struct dax_region { 
 * @region - parent region

 * @dev - device backing the character device

 * @cdev - core chardev data

 * @alive - !alive + rcu grace period == no new mappings can be established

 * @alive - !alive + srcu grace period == no new mappings can be established

 * @id - child id in the region

 * @num_resources - number of physical address extents in this device

 * @res - array of physical address ranges
@@ -569,7 +570,7 @@ static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf) 
static int dax_dev_huge_fault(struct vm_fault *vmf,

		enum page_entry_size pe_size)

{

	int rc;

	int rc, id;

	struct file *filp = vmf->vma->vm_file;

	struct dax_dev *dax_dev = filp->private_data;
@@ -578,7 +579,7 @@ static int dax_dev_huge_fault(struct vm_fault *vmf, 
			? "write" : "read",

			vmf->vma->vm_start, vmf->vma->vm_end);



	rcu_read_lock();

	id = srcu_read_lock(&dax_srcu);

	switch (pe_size) {

	case PE_SIZE_PTE:

		rc = __dax_dev_pte_fault(dax_dev, vmf);
@@ -592,7 +593,7 @@ static int dax_dev_huge_fault(struct vm_fault *vmf, 
	default:

		return VM_FAULT_FALLBACK;

	}

	rcu_read_unlock();

	srcu_read_unlock(&dax_srcu, id);



	return rc;

}
@@ -713,11 +714,11 @@ static void unregister_dax_dev(void *dev) 
	 * Note, rcu is not protecting the liveness of dax_dev, rcu is

	 * ensuring that any fault handlers that might have seen

	 * dax_dev->alive == true, have completed.  Any fault handlers

	 * that start after synchronize_rcu() has started will abort

	 * that start after synchronize_srcu() has started will abort

	 * upon seeing dax_dev->alive == false.

	 */

	dax_dev->alive = false;

	synchronize_rcu();

	synchronize_srcu(&dax_srcu);

	unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1);

	cdev_del(cdev);

	device_unregister(dev);

drivers/nvdimm/bus.c

+6 −0
Original line number Diff line number Diff line
@@ -934,8 +934,14 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm, 
	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, NULL);

	if (rc < 0)

		goto out_unlock;

	nvdimm_bus_unlock(&nvdimm_bus->dev);



	if (copy_to_user(p, buf, buf_len))

		rc = -EFAULT;



	vfree(buf);

	return rc;



 out_unlock:

	nvdimm_bus_unlock(&nvdimm_bus->dev);

 out: