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

Pull libnvdimm fixes from Dan Williams:
 "1/ Two regression fixes since v4.6: one for the byte order of a sysfs
     attribute (bz121161) and another for QEMU 2.6's NVDIMM _DSM (ACPI
     Device Specific Method) implementation that gets tripped up by new
     auto-probing behavior in the NFIT driver.

  2/ A fix tagged for -stable that stops the kernel from
     clobbering/ignoring changes to the configuration of a 'pfn'
     instance ("struct page" driver).  For example changing the
     alignment from 2M to 1G may silently revert to 2M if that value is
     currently stored on media.

  3/ A fix from Eric for an xfstests failure in dax.  It is not
     currently tagged for -stable since it requires an 8-exabyte file
     system to trigger, and there appear to be no user visible side
     effects"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  nfit: fix format interface code byte order
  dax: fix offset overflow in dax_io
  acpi, nfit: fix acpi_check_dsm() vs zero functions implemented
  libnvdimm, pfn, dax: fix initialization vs autodetect for mode + alignment

5 files changed, 60 insertions, 26 deletions

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 2215fc847fa9..ac6ddcc080d4 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -928,7 +928,7 @@ static ssize_t format_show(struct device *dev,
 {
         struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
 
-        return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->code));
+        return sprintf(buf, "0x%04x\n", le16_to_cpu(dcr->code));
 }
 static DEVICE_ATTR_RO(format);
 
@@ -961,8 +961,8 @@ static ssize_t format1_show(struct device *dev,
                                 continue;
                         if (nfit_dcr->dcr->code == dcr->code)
                                 continue;
-                        rc = sprintf(buf, "%#x\n",
-                                        be16_to_cpu(nfit_dcr->dcr->code));
+                        rc = sprintf(buf, "0x%04x\n",
+                                        le16_to_cpu(nfit_dcr->dcr->code));
                         break;
                 }
                 if (rc != ENXIO)
@@ -1131,11 +1131,11 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 
         /*
          * Until standardization materializes we need to consider up to 3
-         * different command sets.  Note, that checking for function0 (bit0)
-         * tells us if any commands are reachable through this uuid.
+         * different command sets.  Note, that checking for zero functions
+         * tells us if any commands might be reachable through this uuid.
          */
         for (i = NVDIMM_FAMILY_INTEL; i <= NVDIMM_FAMILY_HPE2; i++)
-                if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 1))
+                if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 0))
                         break;
 
         /* limit the supported commands to those that are publicly documented */
diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h
index 11cb38348aef..02b9ea1e8d2e 100644
--- a/drivers/acpi/nfit.h
+++ b/drivers/acpi/nfit.h
@@ -53,12 +53,12 @@ enum nfit_uuids {
 };
 
 /*
- * Region format interface codes are stored as an array of bytes in the
- * NFIT DIMM Control Region structure
+ * Region format interface codes are stored with the interface as the
+ * LSB and the function as the MSB.
  */
-#define NFIT_FIC_BYTE cpu_to_be16(0x101) /* byte-addressable energy backed */
-#define NFIT_FIC_BLK cpu_to_be16(0x201) /* block-addressable non-energy backed */
-#define NFIT_FIC_BYTEN cpu_to_be16(0x301) /* byte-addressable non-energy backed */
+#define NFIT_FIC_BYTE cpu_to_le16(0x101) /* byte-addressable energy backed */
+#define NFIT_FIC_BLK cpu_to_le16(0x201) /* block-addressable non-energy backed */
+#define NFIT_FIC_BYTEN cpu_to_le16(0x301) /* byte-addressable non-energy backed */
 
 enum {
         NFIT_BLK_READ_FLUSH = 1,
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 22c09952e177..b4de130f2d57 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -680,9 +680,6 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, u64 rev, u64 funcs)
         u64 mask = 0;
         union acpi_object *obj;
 
-        if (funcs == 0)
-                return false;
-
         obj = acpi_evaluate_dsm(handle, uuid, rev, 0, NULL);
         if (!obj)
                 return false;
@@ -695,6 +692,9 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, u64 rev, u64 funcs)
                         mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
         ACPI_FREE(obj);
 
+        if (funcs == 0)
+                return true;
+
         /*
          * Bit 0 indicates whether there's support for any functions other than
          * function 0 for the specified UUID and revision.
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index f7718ec685fa..cea8350fbc7e 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -344,6 +344,8 @@ struct device *nd_pfn_create(struct nd_region *nd_region)
 int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 {
         u64 checksum, offset;
+        unsigned long align;
+        enum nd_pfn_mode mode;
         struct nd_namespace_io *nsio;
         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
         struct nd_namespace_common *ndns = nd_pfn->ndns;
@@ -386,22 +388,50 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
                 return -ENXIO;
         }
 
+        align = le32_to_cpu(pfn_sb->align);
+        offset = le64_to_cpu(pfn_sb->dataoff);
+        if (align == 0)
+                align = 1UL << ilog2(offset);
+        mode = le32_to_cpu(pfn_sb->mode);
+
         if (!nd_pfn->uuid) {
-                /* from probe we allocate */
+                /*
+                 * When probing a namepace via nd_pfn_probe() the uuid
+                 * is NULL (see: nd_pfn_devinit()) we init settings from
+                 * pfn_sb
+                 */
                 nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
                 if (!nd_pfn->uuid)
                         return -ENOMEM;
+                nd_pfn->align = align;
+                nd_pfn->mode = mode;
         } else {
-                /* from init we validate */
+                /*
+                 * When probing a pfn / dax instance we validate the
+                 * live settings against the pfn_sb
+                 */
                 if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
                         return -ENODEV;
+
+                /*
+                 * If the uuid validates, but other settings mismatch
+                 * return EINVAL because userspace has managed to change
+                 * the configuration without specifying new
+                 * identification.
+                 */
+                if (nd_pfn->align != align || nd_pfn->mode != mode) {
+                        dev_err(&nd_pfn->dev,
+                                        "init failed, settings mismatch\n");
+                        dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
+                                        nd_pfn->align, align, nd_pfn->mode,
+                                        mode);
+                        return -EINVAL;
+                }
         }
 
-        if (nd_pfn->align == 0)
-                nd_pfn->align = le32_to_cpu(pfn_sb->align);
-        if (nd_pfn->align > nvdimm_namespace_capacity(ndns)) {
+        if (align > nvdimm_namespace_capacity(ndns)) {
                 dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
-                                nd_pfn->align, nvdimm_namespace_capacity(ndns));
+                                align, nvdimm_namespace_capacity(ndns));
                 return -EINVAL;
         }
 
@@ -411,7 +441,6 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
          * namespace has changed since the pfn superblock was
          * established.
          */
-        offset = le64_to_cpu(pfn_sb->dataoff);
         nsio = to_nd_namespace_io(&ndns->dev);
         if (offset >= resource_size(&nsio->res)) {
                 dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
@@ -419,10 +448,11 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
                 return -EBUSY;
         }
 
-        if ((nd_pfn->align && !IS_ALIGNED(offset, nd_pfn->align))
+        if ((align && !IS_ALIGNED(offset, align))
                         || !IS_ALIGNED(offset, PAGE_SIZE)) {
-                dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
-                                offset);
+                dev_err(&nd_pfn->dev,
+                                "bad offset: %#llx dax disabled align: %#lx\n",
+                                offset, align);
                 return -ENXIO;
         }
 
@@ -502,7 +532,6 @@ static struct vmem_altmap *__nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
         res->start += start_pad;
         res->end -= end_trunc;
 
-        nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
         if (nd_pfn->mode == PFN_MODE_RAM) {
                 if (offset < SZ_8K)
                         return ERR_PTR(-EINVAL);
diff --git a/fs/dax.c b/fs/dax.c
index 761495bf5eb9..e207f8f9b700 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -208,7 +208,12 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
                                 dax.addr += first;
                                 size = map_len - first;
                         }
-                        max = min(pos + size, end);
+                        /*
+                         * pos + size is one past the last offset for IO,
+                         * so pos + size can overflow loff_t at extreme offsets.
+                         * Cast to u64 to catch this and get the true minimum.
+                         */
+                        max = min_t(u64, pos + size, end);
                 }
 
                 if (iov_iter_rw(iter) == WRITE) {