Merge tag 'libnvdimm-for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm from Dan Williams:
 "A rework of media error handling in the BTT driver and other updates.
  It has appeared in a few -next releases and collected some late-
  breaking build-error and warning fixups as a result.

  Summary:

   - Media error handling support in the Block Translation Table (BTT)
     driver is reworked to address sleeping-while-atomic locking and
     memory-allocation-context conflicts.

   - The dax_device lookup overhead for xfs and ext4 is moved out of the
     iomap hot-path to a mount-time lookup.

   - A new 'ecc_unit_size' sysfs attribute is added to advertise the
     read-modify-write boundary property of a persistent memory range.

   - Preparatory fix-ups for arm and powerpc pmem support are included
     along with other miscellaneous fixes"

* tag 'libnvdimm-for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (26 commits)
  libnvdimm, btt: fix format string warnings
  libnvdimm, btt: clean up warning and error messages
  ext4: fix null pointer dereference on sbi
  libnvdimm, nfit: move the check on nd_reserved2 to the endpoint
  dax: fix FS_DAX=n BLOCK=y compilation
  libnvdimm: fix integer overflow static analysis warning
  libnvdimm, nd_blk: remove mmio_flush_range()
  libnvdimm, btt: rework error clearing
  libnvdimm: fix potential deadlock while clearing errors
  libnvdimm, btt: cache sector_size in arena_info
  libnvdimm, btt: ensure that flags were also unchanged during a map_read
  libnvdimm, btt: refactor map entry operations with macros
  libnvdimm, btt: fix a missed NVDIMM_IO_ATOMIC case in the write path
  libnvdimm, nfit: export an 'ecc_unit_size' sysfs attribute
  ext4: perform dax_device lookup at mount
  ext2: perform dax_device lookup at mount
  xfs: perform dax_device lookup at mount
  dax: introduce a fs_dax_get_by_bdev() helper
  libnvdimm, btt: check memory allocation failure
  libnvdimm, label: fix index block size calculation
  ...

1 files changed, 16 insertions, 14 deletions

diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index 87796f840777..9c5f108910e3 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -45,12 +45,14 @@ unsigned sizeof_namespace_label(struct nvdimm_drvdata *ndd)
 	return ndd->nslabel_size;
 }
 
-size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
+int nvdimm_num_label_slots(struct nvdimm_drvdata *ndd)
 {
-	u32 index_span;
+	return ndd->nsarea.config_size / (sizeof_namespace_label(ndd) + 1);
+}
 
-	if (ndd->nsindex_size)
-		return ndd->nsindex_size;
+size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
+{
+	u32 nslot, space, size;
 
 	/*
 	 * The minimum index space is 512 bytes, with that amount of
@@ -60,16 +62,16 @@ size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
 	 * starts to waste space at larger config_sizes, but it's
 	 * unlikely we'll ever see anything but 128K.
 	 */
-	index_span = ndd->nsarea.config_size / (sizeof_namespace_label(ndd) + 1);
-	index_span /= NSINDEX_ALIGN * 2;
-	ndd->nsindex_size = index_span * NSINDEX_ALIGN;
-
-	return ndd->nsindex_size;
-}
-
-int nvdimm_num_label_slots(struct nvdimm_drvdata *ndd)
-{
-	return ndd->nsarea.config_size / (sizeof_namespace_label(ndd) + 1);
+	nslot = nvdimm_num_label_slots(ndd);
+	space = ndd->nsarea.config_size - nslot * sizeof_namespace_label(ndd);
+	size = ALIGN(sizeof(struct nd_namespace_index) + DIV_ROUND_UP(nslot, 8),
+			NSINDEX_ALIGN) * 2;
+	if (size <= space)
+		return size / 2;
+
+	dev_err(ndd->dev, "label area (%d) too small to host (%d byte) labels\n",
+			ndd->nsarea.config_size, sizeof_namespace_label(ndd));
+	return 0;
 }
 
 static int __nd_label_validate(struct nvdimm_drvdata *ndd)