Add lazy-umount-mountpoint page and mount -a FAQ (#1573)

mkdocs/docs/config/lazy-umount-mountpoint.md

@@ -0,0 +1,27 @@
+# lazy-umount-mountpoint
+
+* type: `BOOL`
+* default: `false`
+* example: `lazy-umount-mountpoint=true`
+
+When enabled mergerfs will issue a [lazy
+umount](https://man7.org/linux/man-pages/man8/umount.8.html) request
+to the mount point as it starts.
+
+```
+Lazy unmount. Detach the filesystem from the file hierarchy
+now, and clean up all references to this filesystem as soon as
+it is not busy anymore.
+```
+
+The value of using this is in situations where you wish to change
+options which can only be set at initialization or upgrade mergerfs
+itself. It also helps in the case of using `mount -a` which leads to a
+new instance of mergerfs being mounted due to it being unable to
+recognize that it is already mounted.
+
+In theory mergerfs could notice that an instance is already mounted at
+the mount point and attempt to use the runtime interface to modify the
+options and only mounting a new instance if the version has changed or
+initialization time only options are changed. However, given the
+relative rarity of this being an issue it isn't a priority.

mkdocs/docs/faq/technical_behavior_and_limitations.md

@@ -282,3 +282,8 @@ Every incoming request contains:
 
 Naturally the mergerfs config as well as anything queriable from the
 operating system or filesystems are also available.
+
+
+## Why does running `mount -a` result in new instances of mergerfs?
+
+See [lazy-umount-mountpoint](../config/lazy-umount-mountpoint.md)

mkdocs/mkdocs.yml

@@ -95,6 +95,7 @@ nav:
   - config/flush-on-close.md
   - config/export-support.md
   - config/kernel-permissions-check.md
+  - config/lazy-umount-mountpoint.md
 - error_handling_and_logging.md
 - resource_usage.md
 - runtime_interface.md

mkdocs/regenerate-docs

@@ -6,7 +6,7 @@ current_branch="$(git branch --show-current)"
 mike delete --all --push --allow-empty --ignore-remote-status
 
 git checkout "master"
-mike deploy --push "preview" "master"
+mike deploy --push "latest" "master"
 
 for tag in $(git tag -l | sort --version-sort --reverse)
 do
@@ -16,10 +16,11 @@ do
     fi
 done
 
-latest="$(git tag -l | sort --version-sort --reverse | head -n 1)"
-git checkout "${latest}"
-mike alias --push "${latest}" "latest"
+#latest="$(git tag -l | sort --version-sort --reverse | head -n 1)"
+#git checkout "${latest}"
+#mike alias --push "${latest}" "latest"
+#mike alias --push "latest" "latest"
 
-mike set-default --push "preview"
+mike set-default --push "latest"
 
 git checkout "${current_branch}"