From f440f1461345add1f1c6cd8f3feaf359176a1170 Mon Sep 17 00:00:00 2001
From: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Date: Thu, 24 Mar 2016 09:14:38 +0800
Subject: [PATCH] Add disk quota support for btrfs

Signed-off-by: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
---
 docs/reference/commandline/dockerd.md | 20 +++++++++++++++++---
 man/docker-create.1.md                |  1 +
 man/docker-run.1.md                   |  3 ++-
 man/dockerd.8.md                      | 17 ++++++++++++++---
 4 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/docs/reference/commandline/dockerd.md b/docs/reference/commandline/dockerd.md
index 842e0516..2ecadbed 100644
--- a/docs/reference/commandline/dockerd.md
+++ b/docs/reference/commandline/dockerd.md
@@ -185,8 +185,10 @@ Linux kernel as of [3.18.0](https://lkml.org/lkml/2014/10/26/137). Call
 ### Storage driver options
 
 Particular storage-driver can be configured with options specified with
-`--storage-opt` flags. Options for `devicemapper` are prefixed with `dm` and
-options for `zfs` start with `zfs`.
+`--storage-opt` flags. Options for `devicemapper` are prefixed with `dm`,
+options for `zfs` start with `zfs` and options for `btrfs` start with `btrfs`.
+
+#### Devicemapper options
 
 *  `dm.thinpooldev`
 
@@ -470,7 +472,7 @@ options for `zfs` start with `zfs`.
     $ dockerd --storage-opt dm.min_free_space=10%
     ```
 
-Currently supported options of `zfs`:
+#### ZFS options
 
 * `zfs.fsname`
 
@@ -482,6 +484,18 @@ Currently supported options of `zfs`:
 
         $ dockerd -s zfs --storage-opt zfs.fsname=zroot/docker
 
+#### Btrfs options
+
+* `btrfs.min_space`
+
+    Specifies the mininum size to use when creating the subvolume which is used
+    for containers. If user uses disk quota for btrfs when creating or running
+    a container with **--storage-opt size** option, docker should ensure the
+    **size** cannot be smaller than **btrfs.min_space**.
+
+    Example use:
+        $ docker daemon -s btrfs --storage-opt btrfs.min_space=10G
+
 ## Docker runtime execution options
 
 The Docker daemon relies on a
diff --git a/man/docker-create.1.md b/man/docker-create.1.md
index 3f90a3a1..f8a80cd3 100644
--- a/man/docker-create.1.md
+++ b/man/docker-create.1.md
@@ -333,6 +333,7 @@ unit, `b` is used. Set LIMIT to `-1` to enable unlimited swap.
    $ docker create -it --storage-opt size=120G fedora /bin/bash
 
    This (size) will allow to set the container rootfs size to 120G at creation time. User cannot pass a size less than the Default BaseFS Size.
+   This option is only available for the `devicemapper`, `btrfs` and `zfs` graphrivers.
   
 **--stop-signal**=*SIGTERM*
   Signal to stop a container. Default is SIGTERM.
diff --git a/man/docker-run.1.md b/man/docker-run.1.md
index 921ff9a0..8fb856b5 100644
--- a/man/docker-run.1.md
+++ b/man/docker-run.1.md
@@ -484,7 +484,8 @@ its root filesystem mounted as read only prohibiting any writes.
    $ docker run -it --storage-opt size=120G fedora /bin/bash
 
    This (size) will allow to set the container rootfs size to 120G at creation time. User cannot pass a size less than the Default BaseFS Size.
-  
+   This option is only available for the `devicemapper`, `btrfs` and `zfs` graphrivers.
+
 **--stop-signal**=*SIGTERM*
   Signal to stop a container. Default is SIGTERM.
 
diff --git a/man/dockerd.8.md b/man/dockerd.8.md
index 74d7ce6a..2c381fb0 100644
--- a/man/dockerd.8.md
+++ b/man/dockerd.8.md
@@ -247,9 +247,9 @@ backends use operating system level technologies and can be
 configured.
 
 Specify options to the storage backend with **--storage-opt** flags. The
-backends that currently take options are *devicemapper* and *zfs*.
-Options for *devicemapper* are prefixed with *dm* and options for *zfs*
-start with *zfs*.
+backends that currently take options are *devicemapper*, *zfs* and *btrfs*.
+Options for *devicemapper* are prefixed with *dm*, options for *zfs*
+start with *zfs* and options for *btrfs* start with *btrfs*.
 
 Specifically for devicemapper, the default is a "loopback" model which
 requires no pre-configuration, but is extremely inefficient.  Do not
@@ -511,6 +511,17 @@ By default docker will pick up the zfs filesystem where docker graph
 
 Example use: `dockerd -s zfs --storage-opt zfs.fsname=zroot/docker`
 
+## Btrfs options
+
+#### btrfs.min_space
+
+Specifies the mininum size to use when creating the subvolume which is used
+for containers. If user uses disk quota for btrfs when creating or running
+a container with **--storage-opt size** option, docker should ensure the
+**size** cannot be smaller than **btrfs.min_space**.
+
+Example use: `docker daemon -s btrfs --storage-opt btrfs.min_space=10G`
+
 # CLUSTER STORE OPTIONS
 
 The daemon uses libkv to advertise