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authorLinus Torvalds <torvalds@linux-foundation.org>2017-04-15 14:07:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-04-15 14:07:03 -0700
commitd5ff0814fda50f0306e102f39640cf5bb76af08e (patch)
treed6b145670fa7cb6bbd91432bbc7410734166adeb
parent403a39f8b0c7b819f8c7ea14bc81f598b1d352cf (diff)
parent11e63f6d920d6f2dfd3cd421e939a4aec9a58dcd (diff)
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)
-rw-r--r--arch/x86/include/asm/pmem.h42
-rw-r--r--drivers/acpi/nfit/core.c6
-rw-r--r--drivers/dax/Kconfig1
-rw-r--r--drivers/dax/dax.c13
-rw-r--r--drivers/nvdimm/bus.c6
-rw-r--r--drivers/nvdimm/claim.c10
-rw-r--r--drivers/nvdimm/dimm_devs.c77
7 files changed, 70 insertions, 85 deletions
diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h
index 2c1ebeb4d737..529bb4a6487a 100644
--- a/arch/x86/include/asm/pmem.h
+++ b/arch/x86/include/asm/pmem.h
@@ -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;
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 662036bdc65e..c8ea9d698cd0 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -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 */
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
index 3e2ab3b14eea..9e95bf94eb13 100644
--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -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
diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 80c6db279ae1..806f180c80d8 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -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);
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 23d4a1728cdf..351bac8f6503 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -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:
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index b3323c0697f6..ca6d572c48fc 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -243,7 +243,15 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
}
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
- if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)) {
+ /*
+ * FIXME: nsio_rw_bytes() may be called from atomic
+ * context in the btt case and nvdimm_clear_poison()
+ * takes a sleeping lock. Until the locking can be
+ * reworked this capability requires that the namespace
+ * is not claimed by btt.
+ */
+ if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
+ && (!ndns->claim || !is_nd_btt(ndns->claim))) {
long cleared;
cleared = nvdimm_clear_poison(&ndns->dev, offset, size);
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 0eedc49e0d47..8b721321be5b 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -395,7 +395,7 @@ EXPORT_SYMBOL_GPL(nvdimm_create);
int alias_dpa_busy(struct device *dev, void *data)
{
- resource_size_t map_end, blk_start, new, busy;
+ resource_size_t map_end, blk_start, new;
struct blk_alloc_info *info = data;
struct nd_mapping *nd_mapping;
struct nd_region *nd_region;
@@ -436,29 +436,19 @@ int alias_dpa_busy(struct device *dev, void *data)
retry:
/*
* Find the free dpa from the end of the last pmem allocation to
- * the end of the interleave-set mapping that is not already
- * covered by a blk allocation.
+ * the end of the interleave-set mapping.
*/
- busy = 0;
for_each_dpa_resource(ndd, res) {
+ if (strncmp(res->name, "pmem", 4) != 0)
+ continue;
if ((res->start >= blk_start && res->start < map_end)
|| (res->end >= blk_start
&& res->end <= map_end)) {
- if (strncmp(res->name, "pmem", 4) == 0) {
- new = max(blk_start, min(map_end + 1,
- res->end + 1));
- if (new != blk_start) {
- blk_start = new;
- goto retry;
- }
- } else
- busy += min(map_end, res->end)
- - max(nd_mapping->start, res->start) + 1;
- } else if (nd_mapping->start > res->start
- && map_end < res->end) {
- /* total eclipse of the PMEM region mapping */
- busy += nd_mapping->size;
- break;
+ new = max(blk_start, min(map_end + 1, res->end + 1));
+ if (new != blk_start) {
+ blk_start = new;
+ goto retry;
+ }
}
}
@@ -470,52 +460,11 @@ int alias_dpa_busy(struct device *dev, void *data)
return 1;
}
- info->available -= blk_start - nd_mapping->start + busy;
+ info->available -= blk_start - nd_mapping->start;
return 0;
}
-static int blk_dpa_busy(struct device *dev, void *data)
-{
- struct blk_alloc_info *info = data;
- struct nd_mapping *nd_mapping;
- struct nd_region *nd_region;
- resource_size_t map_end;
- int i;
-
- if (!is_nd_pmem(dev))
- return 0;
-
- nd_region = to_nd_region(dev);
- for (i = 0; i < nd_region->ndr_mappings; i++) {
- nd_mapping = &nd_region->mapping[i];
- if (nd_mapping->nvdimm == info->nd_mapping->nvdimm)
- break;
- }
-
- if (i >= nd_region->ndr_mappings)
- return 0;
-
- map_end = nd_mapping->start + nd_mapping->size - 1;
- if (info->res->start >= nd_mapping->start
- && info->res->start < map_end) {
- if (info->res->end <= map_end) {
- info->busy = 0;
- return 1;
- } else {
- info->busy -= info->res->end - map_end;
- return 0;
- }
- } else if (info->res->end >= nd_mapping->start
- && info->res->end <= map_end) {
- info->busy -= nd_mapping->start - info->res->start;
- return 0;
- } else {
- info->busy -= nd_mapping->size;
- return 0;
- }
-}
-
/**
* nd_blk_available_dpa - account the unused dpa of BLK region
* @nd_mapping: container of dpa-resource-root + labels
@@ -545,11 +494,7 @@ resource_size_t nd_blk_available_dpa(struct nd_region *nd_region)
for_each_dpa_resource(ndd, res) {
if (strncmp(res->name, "blk", 3) != 0)
continue;
-
- info.res = res;
- info.busy = resource_size(res);
- device_for_each_child(&nvdimm_bus->dev, &info, blk_dpa_busy);
- info.available -= info.busy;
+ info.available -= resource_size(res);
}
return info.available;