overlay2: add support for --storage-opt size

Allow passing --storage-opt size=X to docker create/run commands
for the `overlay2` graphriver.

The size option is only available if the backing fs is xfs that is
mounted with the `pquota` mount option.
The user can pass any size less then the backing fs size.

Signed-off-by: Amir Goldstein <amir73il@aquasec.com>

docs/reference/commandline/create.md

@@ -167,8 +167,13 @@ Set storage driver options per container.
     $ 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 
+This option is only available for the `devicemapper`, `btrfs`, `overlay2`,
-available for the `devicemapper`, `btrfs`, `windowsfilter`, and `zfs` graph drivers.
+`windowsfilter` and `zfs` graph drivers.
+For the `devicemapper`, `btrfs`, `windowsfilter` and `zfs` graph drivers,
+user cannot pass a size less than the Default BaseFS Size.
+For the `overlay2` storage driver, the size option is only available if the
+backing fs is `xfs` and mounted with the `pquota` mount option.
+Under these conditions, user can pass any size less then the backing fs size.
 
 ### Specify isolation technology for container (--isolation)
 

docs/reference/commandline/run.md

@@ -194,8 +194,13 @@ The `-w` lets the command being executed inside directory given, here
     $ 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
+This option is only available for the `devicemapper`, `btrfs`, `overlay2`,
-available for the `devicemapper`, `btrfs`, `windowsfilter`, and `zfs` graph drivers.
+`windowsfilter` and `zfs` graph drivers.
+For the `devicemapper`, `btrfs`, `windowsfilter` and `zfs` graph drivers,
+user cannot pass a size less than the Default BaseFS Size.
+For the `overlay2` storage driver, the size option is only available if the
+backing fs is `xfs` and mounted with the `pquota` mount option.
+Under these conditions, user can pass any size less then the backing fs size.
 
 ### Mount tmpfs (--tmpfs)
 

man/docker-create.1.md

@@ -343,8 +343,11 @@ 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 (size) will allow to set the container rootfs size to 120G at creation time.
-   This option is only available for the `devicemapper`, `btrfs`, and `zfs` graph drivers.
+   This option is only available for the `devicemapper`, `btrfs`, `overlay2` and `zfs` graph drivers.
+   For the `devicemapper`, `btrfs` and `zfs` storage drivers, user cannot pass a size less than the Default BaseFS Size.
+   For the `overlay2` storage driver, the size option is only available if the backing fs is `xfs` and mounted with the `pquota` mount option.
+   Under these conditions, user can pass any size less then the backing fs size.
   
 **--stop-signal**=*SIGTERM*
   Signal to stop a container. Default is SIGTERM.

man/docker-run.1.md

@@ -493,8 +493,11 @@ incompatible with any restart policy other than `none`.
 
    $ 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 (size) will allow to set the container rootfs size to 120G at creation time.
-   This option is only available for the `devicemapper`, `btrfs`, and `zfs` graph drivers.
+   This option is only available for the `devicemapper`, `btrfs`, `overlay2`  and `zfs` graph drivers.
+   For the `devicemapper`, `btrfs` and `zfs` storage drivers, user cannot pass a size less than the Default BaseFS Size.
+   For the `overlay2` storage driver, the size option is only available if the backing fs is `xfs` and mounted with the `pquota` mount option.
+   Under these conditions, user can pass any size less then the backing fs size.
 
 **--stop-signal**=*SIGTERM*
   Signal to stop a container. Default is SIGTERM.