From 79e24839d53f879ad047469f22cc7102362fa999 Mon Sep 17 00:00:00 2001
From: Antonio SJ Musumeci <trapexit@spawn.link>
Date: Wed, 17 Sep 2025 23:55:57 -0500
Subject: [PATCH] Update docs regarding idmap support

---
 mkdocs/docs/config/kernel-permissions-check.md       |  2 +-
 mkdocs/docs/config/options.md                        |  3 +++
 .../docs/faq/technical_behavior_and_limitations.md   | 12 ++++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/mkdocs/docs/config/kernel-permissions-check.md b/mkdocs/docs/config/kernel-permissions-check.md
index 547c818a..c4fb253e 100644
--- a/mkdocs/docs/config/kernel-permissions-check.md
+++ b/mkdocs/docs/config/kernel-permissions-check.md
@@ -16,4 +16,4 @@ help. Like [export-support](export-support.md) this is mostly for
 debugging.
 
 This option is a kernel mount option so unable to be changed at
-runtime.
+runtime. It controls the `default_permissions` FUSE kernel option.
diff --git a/mkdocs/docs/config/options.md b/mkdocs/docs/config/options.md
index 8a282dad..5695e98e 100644
--- a/mkdocs/docs/config/options.md
+++ b/mkdocs/docs/config/options.md
@@ -86,6 +86,9 @@ config file.
 * **[export-support](export-support.md)=BOOL**: Sets a low-level FUSE
   feature intended to indicate the filesystem can support being
   exported via NFS. (default: true)
+* **[kernel-permissions-check](kernel-permissions-check.md)=BOOL**:
+  Controls the FUSE `default_permissions` option. Primarily for
+  debugging. (default: true)
 * **security_capability=BOOL**: If false return ENOATTR when xattr
   security.capability is queried. (default: true)
 * **[xattr](xattr.md)=passthrough|noattr|nosys**: Runtime control of
diff --git a/mkdocs/docs/faq/technical_behavior_and_limitations.md b/mkdocs/docs/faq/technical_behavior_and_limitations.md
index 50dfc3a0..136aaa0d 100644
--- a/mkdocs/docs/faq/technical_behavior_and_limitations.md
+++ b/mkdocs/docs/faq/technical_behavior_and_limitations.md
@@ -201,3 +201,15 @@ contention and therefore lower performance than Linux.
 Additionally, mergerfs [utilizes a cache for supplemental
 groups](../known_issues_bugs.md#supplemental-user-groups) due the the
 high cost of querying that information.
+
+
+## Does mergerfs support idmap?
+
+Yes. At least in so far as it's been enabled now the FUSE itself
+allows a filesystem to indicate it is allowed.
+
+Requires that
+[kernel-permissions-check](../config/kernel-permissions-check.md) be
+enabled (the default.)
+
+If there are any usage issues contact the [author](../support.md).