Merge tag 'ubifs-for-linus-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs

Pull UBI and UBIFS updates from Richard Weinberger:
 "UBI:
   - Add Zhihao Cheng as reviewer
   - Attach via device tree
   - Add NVMEM layer
   - Various fastmap related fixes

  UBIFS:
   - Add Zhihao Cheng as reviewer
   - Convert to folios
   - Various fixes (memory leaks in error paths, function prototypes)"

* tag 'ubifs-for-linus-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs: (34 commits)
  mtd: ubi: fix NVMEM over UBI volumes on 32-bit systems
  mtd: ubi: provide NVMEM layer over UBI volumes
  mtd: ubi: populate ubi volume fwnode
  mtd: ubi: introduce pre-removal notification for UBI volumes
  mtd: ubi: attach from device tree
  mtd: ubi: block: use notifier to create ubiblock from parameter
  dt-bindings: mtd: ubi-volume: allow UBI volumes to provide NVMEM
  dt-bindings: mtd: add basic bindings for UBI
  ubifs: Queue up space reservation tasks if retrying many times
  ubifs: ubifs_symlink: Fix memleak of inode->i_link in error path
  ubifs: dbg_check_idx_size: Fix kmemleak if loading znode failed
  ubi: Correct the number of PEBs after a volume resize failure
  ubi: fix slab-out-of-bounds in ubi_eba_get_ldesc+0xfb/0x130
  ubi: correct the calculation of fastmap size
  ubifs: Remove unreachable code in dbg_check_ltab_lnum
  ubifs: fix function pointer cast warnings
  ubifs: fix sort function prototype
  ubi: Check for too small LEB size in VTBL code
  MAINTAINERS: Add Zhihao Cheng as UBI/UBIFS reviewer
  ubifs: Convert populate_page() to take a folio
  ...

3 files changed, 125 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/mtd/partitions/linux,ubi.yaml b/Documentation/devicetree/bindings/mtd/partitions/linux,ubi.yaml
new file mode 100644
index 000000000000..27e1ac1f252e
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/partitions/linux,ubi.yaml
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/partitions/linux,ubi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Unsorted Block Images
+
+description: |
+  UBI ("Unsorted Block Images") is a volume management system for raw
+  flash devices which manages multiple logical volumes on a single
+  physical flash device and spreads the I/O load (i.e wear-leveling)
+  across the whole flash chip.
+
+maintainers:
+  - Daniel Golle <daniel@makrotopia.org>
+
+allOf:
+  - $ref: partition.yaml#
+
+properties:
+  compatible:
+    const: linux,ubi
+
+  volumes:
+    type: object
+    description: UBI Volumes
+
+    patternProperties:
+      "^ubi-volume-.*$":
+        $ref: /schemas/mtd/partitions/ubi-volume.yaml#
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    partitions {
+        compatible = "fixed-partitions";
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        partition@0 {
+            reg = <0x0 0x100000>;
+            label = "bootloader";
+            read-only;
+        };
+
+        partition@100000 {
+            reg = <0x100000 0x1ff00000>;
+            label = "ubi";
+            compatible = "linux,ubi";
+
+            volumes {
+                ubi-volume-caldata {
+                    volid = <2>;
+                    volname = "rf";
+
+                    nvmem-layout {
+                        compatible = "fixed-layout";
+                        #address-cells = <1>;
+                        #size-cells = <1>;
+
+                        eeprom@0 {
+                            reg = <0x0 0x1000>;
+                        };
+                    };
+                };
+            };
+        };
+    };
diff --git a/Documentation/devicetree/bindings/mtd/partitions/ubi-volume.yaml b/Documentation/devicetree/bindings/mtd/partitions/ubi-volume.yaml
new file mode 100644
index 000000000000..19736b26056b
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/partitions/ubi-volume.yaml
@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/partitions/ubi-volume.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: UBI volume
+
+description: |
+  This binding describes a single UBI volume. Volumes can be matches either
+  by their ID or their name, or both.
+
+maintainers:
+  - Daniel Golle <daniel@makrotopia.org>
+
+properties:
+  volid:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Match UBI volume ID
+
+  volname:
+    $ref: /schemas/types.yaml#/definitions/string
+    description:
+      Match UBI volume ID
+
+  nvmem-layout:
+    $ref: /schemas/nvmem/layouts/nvmem-layout.yaml#
+    description:
+      This container may reference an NVMEM layout parser.
+
+anyOf:
+  - required:
+      - volid
+
+  - required:
+      - volname
+
+# This is a generic file other binding inherit from and extend
+additionalProperties: true
diff --git a/Documentation/mm/page_cache.rst b/Documentation/mm/page_cache.rst
index 75eba7c431b2..138d61f869df 100644
--- a/Documentation/mm/page_cache.rst
+++ b/Documentation/mm/page_cache.rst
@@ -3,3 +3,13 @@
 ==========
 Page Cache
 ==========
+
+The page cache is the primary way that the user and the rest of the kernel
+interact with filesystems.  It can be bypassed (e.g. with O_DIRECT),
+but normal reads, writes and mmaps go through the page cache.
+
+Folios
+======
+
+The folio is the unit of memory management within the page cache.
+Operations