| Message ID | 20201115103718.298186-1-christian.brauner@ubuntu.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | fs: idmapped mounts | expand |
On Sun, 15 Nov 2020 11:36:39 +0100 Christian Brauner <christian.brauner@ubuntu.com> wrote: One quick question... > I have written a simple tool available at > https://github.com/brauner/mount-idmapped that allows to create idmapped > mounts so people can play with this patch series. I spent a while looking at that tool. When actually setting the namespace for the mapping, it uses MOUNT_ATTR_SHIFT rather than MOUNT_ATTR_IDMAP. The value is the same, so I expect it works...:) But did that perhaps not get updated to reflect a name change? Thanks, jon
Hi Christian, Thanks for working on this and respinning this patch series - wanted to chime in below that we on Chrome OS also have lots of exciting use cases for this. On Sun, Nov 15, 2020 at 2:38 AM Christian Brauner <christian.brauner@ubuntu.com> wrote: > > Hey everyone, > > This is v2. It is reworked according to the reviews coming from > Christoph and others to adapt all relevant helpers and inode_operations > methods to account for idmapped mounts instead of introducing new > helpers and methods specific to idmapped mounts like we did before. > We've also moved the overlayfs conversion to handle idmapped mounts into > a separate patchset that will be sent out separately after the core > changes. The converted filesytems in this series include fat and ext4. > The config option to disable idmapped mounts has been moved from a a vfs > config ption to a per-filesystem option. They default to off. Having a > config option allows us to gain some confidence in the patchset over > multiple kernel releases. > > There are two noteable things about this version. First, that it comes > with a really large test-suite to test current vfs behavior and > idmapped mounts behavior. We intend this test-suite to grow over time > and at some point cover most basic core vfs functionality that isn't > covered in xfstests and have it be part of the selftests. > Second, while while working on adapting this patchset to the requested > changes, the runC and containerd crowd was nice enough to adapt > containerd to this patchset to make use of idmapped mounts in one of the > most widely used container runtimes: > https://github.com/containerd/containerd/pull/4734 > > With this patchset we make it possible to attach idmappings to bind > mounts. This handles several common use-cases. Here are just a few: > - Shifting of a container rootfs or base image without having to mangle > every file (runc, Docker, containerd, k8s, LXD, systemd ...) This is one that has hit us repeatedly with Crostini via LXD. We need to change uids/gids to share files and directories with the host. > - Sharing of data between host or privileged containers with > underprivileged containers (runc, Docker, containerd, k8s, LXD, ...) Also useful for sharing data with unprivileged sandboxes like Chrome OS's minijail. > - Shifting of subset of ownership-less filesystems (vfat) for use by > multiple users, effectively allowing for DAC on such devices (systemd, > Android, ...) > - Data sharing between multiple user namespaces with incompatible maps > (LXD, k8s, ...) This may also prove useful sharing data between Chrome OS, Android, and Crostini on the same device. Basically the same use case, although VM boundaries are involved. > Making it possible to share directories and mounts between users with > different uids and gids is itself quite an important use-case in > distributed systems environments. It's of course especially useful in > general for portable usb sticks, sharing data between multiple users in > general, and sharing home directories between multiple users. The last > example is now elegantly expressed in systemd's homed concept for > portable home directories. As mentioned above, idmapped mounts also > allow data from the host to be shared with unprivileged containers, > between privileged and unprivileged containers simultaneously and in > addition also between unprivileged containers with different idmappings > whenever they are used to isolate one container completely from another > container. > As can be seen from answers to earlier threads of this patchset and from > the list of potential users interest in this patchset is fairly > widespread. > > We have implemented and proposed multiple solutions to this before. This > included the introduction of fsid mappings, a tiny filesystem that is > currently carried in Ubuntu that has shown it's limitations, and an > approach to call override creds in the vfs. None of these solutions have > covered all of the above use-cases. Some of them have been fairly hacky > too by e.g. violating how things should be passed down to the individual > filesystems. > The solution proposed here has it's origins in multiple discussions > during Linux Plumbers 2017 during and after the end of the containers > microconference. > To the best of my knowledge this involved Aleksa, Stéphane, Eric, David, > James, and myself. The original idea or a variant thereof has been > discussed, again to the best of my knowledge, after a Linux conference > in St. Petersburg in Russia in 2017 between Christoph, Tycho, and > myself. > We've taken the time to implement a working version of this solution > over the last weeks to the best of my abilities. Tycho has signed up > for this sligthly crazy endeavour as well and he has helped with the > conversion of the xattr codepaths and will be involved with others in > converting additional filesystems. > > This series makes idmappings a property of struct vfsmount instead of > tying it to a process being inside of a user namespace which has been > the case for all other proposed approaches. It also allows to pass down > the user namespace into the filesystms which is a clean way instead of > violating calling conventions by strapping the user namespace > information that is a property of the mount to the caller's credentials > or similar hacks. > With this idmappings become a property of bind-mounts, i.e. each > bind-mount can have a separate idmapping. Such idmapped mounts can even > be created inside of the initial user namespace. > > The vfsmount struct gains a new struct user_namespace member. The > idmapping of the user namespace becomes the idmapping of the mount. A > caller that is privileged with respect to the user namespace of > the superblock of the underlying filesystem can create an idmapped > bind-mount. In the future, we can enable unprivileged use-cases by > checking whether the caller is privileged wrt to the user namespace an > already idmapped mount has been marked with, allowing them to change the > idmapping. For now, keep things simple until we feel sure enough. Note, > that with syscall interception it is already possible to intercept > idmapped mount requests from unprivileged containers and handle them in > a sufficiently privileged container manager. Support for this is > already available in LXD and will be available in runC were syscall > interception is currently becoming part of the runtime spec (see > https://github.com/opencontainers/runtime-spec/pull/1074). > > The user namespace the mount will be marked with can be specified by > passing a file descriptor refering to the user namespace as an argument > to the new mount_setattr() syscall together with the new > MOUNT_ATTR_IDMAP flag. By default vfsmounts are marked with the initial > user namespace and no behavioral or performance changes should be > observed. All mapping operations are nops for the initial user > namespace. When a file/inode is accessed through an idmapped mount the > i_uid and i_gid of the inode will be remapped according to the user > namespace the mount has been marked with. > > In order to support idmapped mounts, filesystems need to be changed and > mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The initial > version contains fat and ext4 including a list of examples. But patches > for other filesystems are actively worked on but will be sent out > separately. We are here to see this through and there are multiple > people involved in converting filesystems. So filesystem developers are > not left alone with this. > > I have written a simple tool available at > https://github.com/brauner/mount-idmapped that allows to create idmapped > mounts so people can play with this patch series. Here are a few > illustrations: > > 1. Create a simple idmapped mount of another user's home directory > > u1001@f2-vm:/$ sudo ./mount-idmapped --map-mount b:1000:1001:1 /home/ubuntu/ /mnt > u1001@f2-vm:/$ ls -al /home/ubuntu/ > total 28 > drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 . > drwxr-xr-x 4 root root 4096 Oct 28 04:00 .. > -rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history > -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout > -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc > -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile > -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful > -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo > u1001@f2-vm:/$ ls -al /mnt/ > total 28 > drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 . > drwxr-xr-x 29 root root 4096 Oct 28 22:01 .. > -rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history > -rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout > -rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc > -rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile > -rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful > -rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo > u1001@f2-vm:/$ touch /mnt/my-file > u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file > u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file > u1001@f2-vm:/$ ls -al /mnt/my-file > -rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file > u1001@f2-vm:/$ ls -al /home/ubuntu/my-file > -rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file > u1001@f2-vm:/$ getfacl /mnt/my-file > getfacl: Removing leading '/' from absolute path names > # file: mnt/my-file > # owner: u1001 > # group: u1001 > user::rw- > user:u1001:rwx > group::rw- > mask::rwx > other::r-- > u1001@f2-vm:/$ getfacl /home/ubuntu/my-file > getfacl: Removing leading '/' from absolute path names > # file: home/ubuntu/my-file > # owner: ubuntu > # group: ubuntu > user::rw- > user:ubuntu:rwx > group::rw- > mask::rwx > other::r-- > > 2. Create mapping of the whole ext4 rootfs without a mapping for uid and gid 0 > > ubuntu@f2-vm:~$ sudo /mount-idmapped --map-mount b:1:1:65536 / /mnt/ > ubuntu@f2-vm:~$ findmnt | grep mnt > └─/mnt /dev/sda2 ext4 rw,relatime > └─/mnt/mnt /dev/sda2 ext4 rw,relatime > ubuntu@f2-vm:~$ sudo mkdir /AS-ROOT-CAN-CREATE > ubuntu@f2-vm:~$ sudo mkdir /mnt/AS-ROOT-CANT-CREATE > mkdir: cannot create directory ‘/mnt/AS-ROOT-CANT-CREATE’: Value too large for defined data type > ubuntu@f2-vm:~$ mkdir /mnt/home/ubuntu/AS-USER-1000-CAN-CREATE > > 3. Create a vfat usb mount and expose to user 1001 and 5000 > > ubuntu@f2-vm:/$ sudo mount /dev/sdb /mnt > ubuntu@f2-vm:/$ findmnt | grep mnt > └─/mnt /dev/sdb vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro > ubuntu@f2-vm:/$ ls -al /mnt > total 12 > drwxr-xr-x 2 root root 4096 Jan 1 1970 . > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > -rwxr-xr-x 1 root root 4 Oct 28 03:44 aaa > -rwxr-xr-x 1 root root 0 Oct 28 01:09 bbb > ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:1001:1 /mnt /mnt-1001/ > ubuntu@f2-vm:/$ ls -al /mnt-1001/ > total 12 > drwxr-xr-x 2 u1001 u1001 4096 Jan 1 1970 . > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > -rwxr-xr-x 1 u1001 u1001 4 Oct 28 03:44 aaa > -rwxr-xr-x 1 u1001 u1001 0 Oct 28 01:09 bbb > ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:5000:1 /mnt /mnt-5000/ > ubuntu@f2-vm:/$ ls -al /mnt-5000/ > total 12 > drwxr-xr-x 2 5000 5000 4096 Jan 1 1970 . > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > -rwxr-xr-x 1 5000 5000 4 Oct 28 03:44 aaa > -rwxr-xr-x 1 5000 5000 0 Oct 28 01:09 bbb > > 4. Create an idmapped rootfs mount for a container > > root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/ > total 68 > drwxr-xr-x 17 20000 20000 4096 Sep 24 07:48 . > drwxrwx--- 3 20000 20000 4096 Oct 16 19:26 .. > lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 bin -> usr/bin > drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 boot > drwxr-xr-x 3 20000 20000 4096 Oct 16 19:26 dev > drwxr-xr-x 61 20000 20000 4096 Oct 16 19:26 etc > drwxr-xr-x 3 20000 20000 4096 Sep 24 07:45 home > lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 lib -> usr/lib > lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib32 -> usr/lib32 > lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib64 -> usr/lib64 > lrwxrwxrwx 1 20000 20000 10 Sep 24 07:43 libx32 -> usr/libx32 > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 media > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 mnt > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 opt > drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 proc > drwx------ 2 20000 20000 4096 Sep 24 07:43 root > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:45 run > lrwxrwxrwx 1 20000 20000 8 Sep 24 07:43 sbin -> usr/sbin > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 srv > drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 sys > drwxrwxrwt 2 20000 20000 4096 Sep 24 07:44 tmp > drwxr-xr-x 13 20000 20000 4096 Sep 24 07:43 usr > drwxr-xr-x 12 20000 20000 4096 Sep 24 07:44 var > root@f2-vm:~# /mount-idmapped --map-mount b:20000:10000:100000 /var/lib/lxc/f2/rootfs/ /mnt > root@f2-vm:~# ls -al /mnt > total 68 > drwxr-xr-x 17 10000 10000 4096 Sep 24 07:48 . > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 bin -> usr/bin > drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 boot > drwxr-xr-x 3 10000 10000 4096 Oct 16 19:26 dev > drwxr-xr-x 61 10000 10000 4096 Oct 16 19:26 etc > drwxr-xr-x 3 10000 10000 4096 Sep 24 07:45 home > lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 lib -> usr/lib > lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib32 -> usr/lib32 > lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib64 -> usr/lib64 > lrwxrwxrwx 1 10000 10000 10 Sep 24 07:43 libx32 -> usr/libx32 > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 media > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 mnt > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 opt > drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 proc > drwx------ 2 10000 10000 4096 Sep 24 07:43 root > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:45 run > lrwxrwxrwx 1 10000 10000 8 Sep 24 07:43 sbin -> usr/sbin > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 srv > drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 sys > drwxrwxrwt 2 10000 10000 4096 Sep 24 07:44 tmp > drwxr-xr-x 13 10000 10000 4096 Sep 24 07:43 usr > drwxr-xr-x 12 10000 10000 4096 Sep 24 07:44 var > root@f2-vm:~# lxc-start f2 # uses /mnt as rootfs > root@f2-vm:~# lxc-attach f2 -- cat /proc/1/uid_map > 0 10000 10000 > root@f2-vm:~# lxc-attach f2 -- cat /proc/1/gid_map > 0 10000 10000 > root@f2-vm:~# lxc-attach f2 -- ls -al / > total 52 > drwxr-xr-x 17 root root 4096 Sep 24 07:48 . > drwxr-xr-x 17 root root 4096 Sep 24 07:48 .. > lrwxrwxrwx 1 root root 7 Sep 24 07:43 bin -> usr/bin > drwxr-xr-x 2 root root 4096 Apr 15 2020 boot > drwxr-xr-x 5 root root 500 Oct 28 23:39 dev > drwxr-xr-x 61 root root 4096 Oct 28 23:39 etc > drwxr-xr-x 3 root root 4096 Sep 24 07:45 home > lrwxrwxrwx 1 root root 7 Sep 24 07:43 lib -> usr/lib > lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib32 -> usr/lib32 > lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib64 -> usr/lib64 > lrwxrwxrwx 1 root root 10 Sep 24 07:43 libx32 -> usr/libx32 > drwxr-xr-x 2 root root 4096 Sep 24 07:43 media > drwxr-xr-x 2 root root 4096 Sep 24 07:43 mnt > drwxr-xr-x 2 root root 4096 Sep 24 07:43 opt > dr-xr-xr-x 232 nobody nogroup 0 Oct 28 23:39 proc > drwx------ 2 root root 4096 Oct 28 23:41 root > drwxr-xr-x 12 root root 360 Oct 28 23:39 run > lrwxrwxrwx 1 root root 8 Sep 24 07:43 sbin -> usr/sbin > drwxr-xr-x 2 root root 4096 Sep 24 07:43 srv > dr-xr-xr-x 13 nobody nogroup 0 Oct 28 23:39 sys > drwxrwxrwt 11 root root 4096 Oct 28 23:40 tmp > drwxr-xr-x 13 root root 4096 Sep 24 07:43 usr > drwxr-xr-x 12 root root 4096 Sep 24 07:44 var > root@f2-vm:~# lxc-attach f2 -- ls -al /my-file > -rw-r--r-- 1 root root 0 Oct 28 23:43 /my-file > root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/my-file > -rw-r--r-- 1 20000 20000 0 Oct 28 23:43 /var/lib/lxc/f2/rootfs/my-file > > I'd like to say thanks to: > Al for pointing me into the direction to avoid inode alias issues during > lookup. David for various discussions around this. Christoph for proving > a first proper review and for being involved in the original idea. Tycho > for helping with this series and on future patches to convert > filesystems. Alban Crequy and the Kinvolk located just a few streets > away from me in Berlin for providing use-case discussions and writing > patches for containerd! Stéphane for his invaluable input on many things > and level head and enabling me to work on this. Amir for explaining and > discussing aspects of overlayfs with me. I'd like to especially thank > Seth Forshee because he provided a lot of good analysis, suggestions, > and participated in short-notice discussions in both chat and video for > some nitty-gritty technical details. > > This series can be found and pulled from the three usual locations: > https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git/log/?h=idmapped_mounts > https://github.com/brauner/linux/tree/idmapped_mounts > https://gitlab.com/brauner/linux/-/commits/idmapped_mounts > > Thanks! > Christian > > Christian Brauner (37): > namespace: take lock_mount_hash() directly when changing flags > mount: make {lock,unlock}_mount_hash() static > namespace: only take read lock in do_reconfigure_mnt() > fs: add mount_setattr() > tests: add mount_setattr() selftests > fs: add id translation helpers > mount: attach mappings to mounts > capability: handle idmapped mounts > namei: add idmapped mount aware permission helpers > inode: add idmapped mount aware init and permission helpers > attr: handle idmapped mounts > acl: handle idmapped mounts > commoncap: handle idmapped mounts > stat: handle idmapped mounts > namei: handle idmapped mounts in may_*() helpers > namei: introduce struct renamedata > namei: prepare for idmapped mounts > open: handle idmapped mounts in do_truncate() > open: handle idmapped mounts > af_unix: handle idmapped mounts > utimes: handle idmapped mounts > fcntl: handle idmapped mounts > notify: handle idmapped mounts > init: handle idmapped mounts > ioctl: handle idmapped mounts > would_dump: handle idmapped mounts > exec: handle idmapped mounts > fs: add helpers for idmap mounts > apparmor: handle idmapped mounts > audit: handle idmapped mounts > ima: handle idmapped mounts > fat: handle idmapped mounts > ext4: support idmapped mounts > ecryptfs: do not mount on top of idmapped mounts > overlayfs: do not mount on top of idmapped mounts > fs: introduce MOUNT_ATTR_IDMAP > tests: add vfs/idmapped mounts test suite > > Tycho Andersen (2): > xattr: handle idmapped mounts > selftests: add idmapped mounts xattr selftest > > Documentation/filesystems/locking.rst | 6 +- > Documentation/filesystems/porting.rst | 2 + > Documentation/filesystems/vfs.rst | 17 +- > arch/alpha/kernel/syscalls/syscall.tbl | 1 + > arch/arm/tools/syscall.tbl | 1 + > arch/arm64/include/asm/unistd32.h | 2 + > arch/ia64/kernel/syscalls/syscall.tbl | 1 + > arch/m68k/kernel/syscalls/syscall.tbl | 1 + > arch/microblaze/kernel/syscalls/syscall.tbl | 1 + > arch/mips/kernel/syscalls/syscall_n32.tbl | 1 + > arch/mips/kernel/syscalls/syscall_n64.tbl | 1 + > arch/mips/kernel/syscalls/syscall_o32.tbl | 1 + > arch/parisc/kernel/syscalls/syscall.tbl | 1 + > arch/powerpc/kernel/syscalls/syscall.tbl | 1 + > arch/powerpc/platforms/cell/spufs/inode.c | 5 +- > arch/s390/kernel/syscalls/syscall.tbl | 1 + > arch/sh/kernel/syscalls/syscall.tbl | 1 + > arch/sparc/kernel/syscalls/syscall.tbl | 1 + > arch/x86/entry/syscalls/syscall_32.tbl | 1 + > arch/x86/entry/syscalls/syscall_64.tbl | 1 + > arch/xtensa/kernel/syscalls/syscall.tbl | 1 + > drivers/android/binderfs.c | 3 +- > drivers/base/devtmpfs.c | 12 +- > fs/9p/acl.c | 7 +- > fs/9p/v9fs.h | 3 +- > fs/9p/v9fs_vfs.h | 2 +- > fs/9p/vfs_inode.c | 32 +- > fs/9p/vfs_inode_dotl.c | 34 +- > fs/9p/xattr.c | 1 + > fs/adfs/adfs.h | 3 +- > fs/adfs/inode.c | 5 +- > fs/affs/affs.h | 10 +- > fs/affs/inode.c | 7 +- > fs/affs/namei.c | 15 +- > fs/afs/dir.c | 34 +- > fs/afs/inode.c | 5 +- > fs/afs/internal.h | 4 +- > fs/afs/security.c | 2 +- > fs/afs/xattr.c | 2 + > fs/attr.c | 78 +- > fs/autofs/root.c | 13 +- > fs/bad_inode.c | 31 +- > fs/bfs/dir.c | 12 +- > fs/btrfs/acl.c | 5 +- > fs/btrfs/ctree.h | 3 +- > fs/btrfs/inode.c | 41 +- > fs/btrfs/ioctl.c | 25 +- > fs/btrfs/tests/btrfs-tests.c | 2 +- > fs/btrfs/xattr.c | 2 + > fs/cachefiles/interface.c | 4 +- > fs/cachefiles/namei.c | 19 +- > fs/cachefiles/xattr.c | 16 +- > fs/ceph/acl.c | 5 +- > fs/ceph/dir.c | 23 +- > fs/ceph/inode.c | 13 +- > fs/ceph/super.h | 8 +- > fs/ceph/xattr.c | 1 + > fs/cifs/cifsfs.c | 4 +- > fs/cifs/cifsfs.h | 18 +- > fs/cifs/dir.c | 8 +- > fs/cifs/inode.c | 22 +- > fs/cifs/link.c | 3 +- > fs/cifs/xattr.c | 1 + > fs/coda/coda_linux.h | 4 +- > fs/coda/dir.c | 18 +- > fs/coda/inode.c | 5 +- > fs/coda/pioctl.c | 6 +- > fs/configfs/configfs_internal.h | 7 +- > fs/configfs/dir.c | 3 +- > fs/configfs/inode.c | 5 +- > fs/configfs/symlink.c | 5 +- > fs/coredump.c | 12 +- > fs/crypto/policy.c | 2 +- > fs/debugfs/inode.c | 9 +- > fs/ecryptfs/crypto.c | 4 +- > fs/ecryptfs/inode.c | 74 +- > fs/ecryptfs/main.c | 6 + > fs/ecryptfs/mmap.c | 4 +- > fs/efivarfs/file.c | 2 +- > fs/efivarfs/inode.c | 4 +- > fs/erofs/inode.c | 2 +- > fs/exec.c | 12 +- > fs/exfat/exfat_fs.h | 3 +- > fs/exfat/file.c | 9 +- > fs/exfat/namei.c | 13 +- > fs/ext2/acl.c | 5 +- > fs/ext2/acl.h | 3 +- > fs/ext2/ext2.h | 2 +- > fs/ext2/ialloc.c | 2 +- > fs/ext2/inode.c | 11 +- > fs/ext2/ioctl.c | 6 +- > fs/ext2/namei.c | 22 +- > fs/ext2/xattr_security.c | 1 + > fs/ext2/xattr_trusted.c | 1 + > fs/ext2/xattr_user.c | 1 + > fs/ext4/Kconfig | 9 + > fs/ext4/acl.c | 5 +- > fs/ext4/acl.h | 3 +- > fs/ext4/ext4.h | 15 +- > fs/ext4/ialloc.c | 7 +- > fs/ext4/inode.c | 14 +- > fs/ext4/ioctl.c | 18 +- > fs/ext4/namei.c | 52 +- > fs/ext4/super.c | 6 +- > fs/ext4/xattr_hurd.c | 1 + > fs/ext4/xattr_security.c | 1 + > fs/ext4/xattr_trusted.c | 1 + > fs/ext4/xattr_user.c | 1 + > fs/f2fs/acl.c | 5 +- > fs/f2fs/acl.h | 3 +- > fs/f2fs/f2fs.h | 3 +- > fs/f2fs/file.c | 23 +- > fs/f2fs/namei.c | 26 +- > fs/f2fs/xattr.c | 4 +- > fs/fat/fat.h | 3 +- > fs/fat/file.c | 20 +- > fs/fat/namei_msdos.c | 15 +- > fs/fat/namei_vfat.c | 15 +- > fs/fcntl.c | 3 +- > fs/fuse/acl.c | 3 +- > fs/fuse/dir.c | 41 +- > fs/fuse/fuse_i.h | 4 +- > fs/fuse/xattr.c | 2 + > fs/gfs2/acl.c | 5 +- > fs/gfs2/acl.h | 3 +- > fs/gfs2/file.c | 4 +- > fs/gfs2/inode.c | 54 +- > fs/gfs2/inode.h | 2 +- > fs/gfs2/xattr.c | 1 + > fs/hfs/attr.c | 1 + > fs/hfs/dir.c | 13 +- > fs/hfs/hfs_fs.h | 2 +- > fs/hfs/inode.c | 7 +- > fs/hfsplus/dir.c | 25 +- > fs/hfsplus/inode.c | 11 +- > fs/hfsplus/ioctl.c | 2 +- > fs/hfsplus/xattr.c | 1 + > fs/hfsplus/xattr_security.c | 1 + > fs/hfsplus/xattr_trusted.c | 1 + > fs/hfsplus/xattr_user.c | 1 + > fs/hostfs/hostfs_kern.c | 31 +- > fs/hpfs/hpfs_fn.h | 2 +- > fs/hpfs/inode.c | 7 +- > fs/hpfs/namei.c | 20 +- > fs/hugetlbfs/inode.c | 31 +- > fs/init.c | 21 +- > fs/inode.c | 38 +- > fs/internal.h | 9 + > fs/jffs2/acl.c | 5 +- > fs/jffs2/acl.h | 3 +- > fs/jffs2/dir.c | 32 +- > fs/jffs2/fs.c | 7 +- > fs/jffs2/os-linux.h | 2 +- > fs/jffs2/security.c | 1 + > fs/jffs2/xattr_trusted.c | 1 + > fs/jffs2/xattr_user.c | 1 + > fs/jfs/acl.c | 5 +- > fs/jfs/file.c | 9 +- > fs/jfs/ioctl.c | 2 +- > fs/jfs/jfs_acl.h | 3 +- > fs/jfs/jfs_inode.c | 2 +- > fs/jfs/jfs_inode.h | 2 +- > fs/jfs/namei.c | 21 +- > fs/jfs/xattr.c | 2 + > fs/kernfs/dir.c | 7 +- > fs/kernfs/inode.c | 15 +- > fs/kernfs/kernfs-internal.h | 5 +- > fs/libfs.c | 20 +- > fs/minix/bitmap.c | 2 +- > fs/minix/file.c | 7 +- > fs/minix/inode.c | 2 +- > fs/minix/namei.c | 25 +- > fs/mount.h | 10 - > fs/namei.c | 317 +- > fs/namespace.c | 473 ++- > fs/nfs/dir.c | 23 +- > fs/nfs/inode.c | 5 +- > fs/nfs/internal.h | 10 +- > fs/nfs/namespace.c | 7 +- > fs/nfs/nfs3_fs.h | 3 +- > fs/nfs/nfs3acl.c | 3 +- > fs/nfs/nfs4proc.c | 3 + > fs/nfsd/nfs2acl.c | 4 +- > fs/nfsd/nfs3acl.c | 4 +- > fs/nfsd/nfs4acl.c | 4 +- > fs/nfsd/nfs4recover.c | 6 +- > fs/nfsd/nfsfh.c | 2 +- > fs/nfsd/nfsproc.c | 2 +- > fs/nfsd/vfs.c | 47 +- > fs/nilfs2/inode.c | 13 +- > fs/nilfs2/ioctl.c | 2 +- > fs/nilfs2/namei.c | 20 +- > fs/nilfs2/nilfs.h | 4 +- > fs/notify/fanotify/fanotify_user.c | 2 +- > fs/notify/inotify/inotify_user.c | 3 +- > fs/ntfs/inode.c | 2 +- > fs/ocfs2/acl.c | 5 +- > fs/ocfs2/acl.h | 3 +- > fs/ocfs2/dlmfs/dlmfs.c | 17 +- > fs/ocfs2/file.c | 13 +- > fs/ocfs2/file.h | 5 +- > fs/ocfs2/ioctl.c | 2 +- > fs/ocfs2/namei.c | 21 +- > fs/ocfs2/refcounttree.c | 4 +- > fs/ocfs2/xattr.c | 3 + > fs/omfs/dir.c | 13 +- > fs/omfs/file.c | 7 +- > fs/omfs/inode.c | 2 +- > fs/open.c | 52 +- > fs/orangefs/acl.c | 5 +- > fs/orangefs/inode.c | 15 +- > fs/orangefs/namei.c | 12 +- > fs/orangefs/orangefs-kernel.h | 7 +- > fs/orangefs/xattr.c | 1 + > fs/overlayfs/copy_up.c | 20 +- > fs/overlayfs/dir.c | 31 +- > fs/overlayfs/file.c | 6 +- > fs/overlayfs/inode.c | 21 +- > fs/overlayfs/overlayfs.h | 40 +- > fs/overlayfs/super.c | 27 +- > fs/overlayfs/util.c | 4 +- > fs/posix_acl.c | 78 +- > fs/proc/base.c | 24 +- > fs/proc/fd.c | 4 +- > fs/proc/fd.h | 3 +- > fs/proc/generic.c | 9 +- > fs/proc/internal.h | 2 +- > fs/proc/proc_net.c | 2 +- > fs/proc/proc_sysctl.c | 12 +- > fs/proc/root.c | 2 +- > fs/proc_namespace.c | 1 + > fs/ramfs/file-nommu.c | 9 +- > fs/ramfs/inode.c | 18 +- > fs/reiserfs/acl.h | 3 +- > fs/reiserfs/inode.c | 7 +- > fs/reiserfs/ioctl.c | 4 +- > fs/reiserfs/namei.c | 21 +- > fs/reiserfs/reiserfs.h | 3 +- > fs/reiserfs/xattr.c | 12 +- > fs/reiserfs/xattr.h | 2 +- > fs/reiserfs/xattr_acl.c | 7 +- > fs/reiserfs/xattr_security.c | 3 +- > fs/reiserfs/xattr_trusted.c | 3 +- > fs/reiserfs/xattr_user.c | 3 +- > fs/remap_range.c | 7 +- > fs/stat.c | 10 +- > fs/sysv/file.c | 7 +- > fs/sysv/ialloc.c | 2 +- > fs/sysv/itree.c | 2 +- > fs/sysv/namei.c | 21 +- > fs/tracefs/inode.c | 4 +- > fs/ubifs/dir.c | 29 +- > fs/ubifs/file.c | 5 +- > fs/ubifs/ioctl.c | 2 +- > fs/ubifs/ubifs.h | 3 +- > fs/ubifs/xattr.c | 1 + > fs/udf/file.c | 9 +- > fs/udf/ialloc.c | 2 +- > fs/udf/namei.c | 24 +- > fs/udf/symlink.c | 2 +- > fs/ufs/ialloc.c | 2 +- > fs/ufs/inode.c | 7 +- > fs/ufs/namei.c | 19 +- > fs/ufs/ufs.h | 3 +- > fs/utimes.c | 4 +- > fs/vboxsf/dir.c | 12 +- > fs/vboxsf/utils.c | 5 +- > fs/vboxsf/vfsmod.h | 3 +- > fs/verity/enable.c | 2 +- > fs/xattr.c | 136 +- > fs/xfs/xfs_acl.c | 5 +- > fs/xfs/xfs_acl.h | 3 +- > fs/xfs/xfs_ioctl.c | 4 +- > fs/xfs/xfs_iops.c | 55 +- > fs/xfs/xfs_xattr.c | 3 +- > fs/zonefs/super.c | 9 +- > include/linux/audit.h | 10 +- > include/linux/capability.h | 14 +- > include/linux/fs.h | 145 +- > include/linux/ima.h | 15 +- > include/linux/lsm_hook_defs.h | 15 +- > include/linux/lsm_hooks.h | 1 + > include/linux/mount.h | 14 +- > include/linux/nfs_fs.h | 4 +- > include/linux/posix_acl.h | 15 +- > include/linux/posix_acl_xattr.h | 12 +- > include/linux/security.h | 44 +- > include/linux/syscalls.h | 3 + > include/linux/xattr.h | 30 +- > include/uapi/asm-generic/unistd.h | 4 +- > include/uapi/linux/mount.h | 25 + > ipc/mqueue.c | 16 +- > kernel/auditsc.c | 29 +- > kernel/bpf/inode.c | 13 +- > kernel/capability.c | 14 +- > kernel/cgroup/cgroup.c | 2 +- > kernel/sys.c | 2 +- > mm/madvise.c | 4 +- > mm/memcontrol.c | 2 +- > mm/mincore.c | 4 +- > mm/shmem.c | 45 +- > net/socket.c | 6 +- > net/unix/af_unix.c | 4 +- > security/apparmor/apparmorfs.c | 3 +- > security/apparmor/domain.c | 13 +- > security/apparmor/file.c | 5 +- > security/apparmor/lsm.c | 12 +- > security/commoncap.c | 46 +- > security/integrity/evm/evm_crypto.c | 11 +- > security/integrity/evm/evm_main.c | 4 +- > security/integrity/evm/evm_secfs.c | 2 +- > security/integrity/ima/ima.h | 19 +- > security/integrity/ima/ima_api.c | 10 +- > security/integrity/ima/ima_appraise.c | 22 +- > security/integrity/ima/ima_asymmetric_keys.c | 2 +- > security/integrity/ima/ima_main.c | 28 +- > security/integrity/ima/ima_policy.c | 17 +- > security/integrity/ima/ima_queue_keys.c | 2 +- > security/security.c | 25 +- > security/selinux/hooks.c | 22 +- > security/smack/smack_lsm.c | 18 +- > tools/include/uapi/asm-generic/unistd.h | 4 +- > tools/testing/selftests/Makefile | 1 + > .../testing/selftests/idmap_mounts/.gitignore | 2 + > tools/testing/selftests/idmap_mounts/Makefile | 12 + > tools/testing/selftests/idmap_mounts/config | 1 + > tools/testing/selftests/idmap_mounts/core.c | 3476 +++++++++++++++++ > .../testing/selftests/idmap_mounts/internal.h | 127 + > tools/testing/selftests/idmap_mounts/utils.c | 136 + > tools/testing/selftests/idmap_mounts/utils.h | 17 + > tools/testing/selftests/idmap_mounts/xattr.c | 172 + > .../selftests/mount_setattr/.gitignore | 1 + > .../testing/selftests/mount_setattr/Makefile | 7 + > tools/testing/selftests/mount_setattr/config | 1 + > .../mount_setattr/mount_setattr_test.c | 889 +++++ > 335 files changed, 7594 insertions(+), 1570 deletions(-) > create mode 100644 tools/testing/selftests/idmap_mounts/.gitignore > create mode 100644 tools/testing/selftests/idmap_mounts/Makefile > create mode 100644 tools/testing/selftests/idmap_mounts/config > create mode 100644 tools/testing/selftests/idmap_mounts/core.c > create mode 100644 tools/testing/selftests/idmap_mounts/internal.h > create mode 100644 tools/testing/selftests/idmap_mounts/utils.c > create mode 100644 tools/testing/selftests/idmap_mounts/utils.h > create mode 100644 tools/testing/selftests/idmap_mounts/xattr.c > create mode 100644 tools/testing/selftests/mount_setattr/.gitignore > create mode 100644 tools/testing/selftests/mount_setattr/Makefile > create mode 100644 tools/testing/selftests/mount_setattr/config > create mode 100644 tools/testing/selftests/mount_setattr/mount_setattr_test.c > > > base-commit: 3cea11cd5e3b00d91caf0b4730194039b45c5891 > -- > 2.29.2 > Thanks! Steve
On Tue, Nov 17, 2020 at 04:54:33PM -0700, Jonathan Corbet wrote: > On Sun, 15 Nov 2020 11:36:39 +0100 > Christian Brauner <christian.brauner@ubuntu.com> wrote: > > One quick question... > > > I have written a simple tool available at > > https://github.com/brauner/mount-idmapped that allows to create idmapped > > mounts so people can play with this patch series. > > I spent a while looking at that tool. When actually setting the namespace > for the mapping, it uses MOUNT_ATTR_SHIFT rather than MOUNT_ATTR_IDMAP. > The value is the same, so I expect it works...:) But did that perhaps not > get updated to reflect a name change? Yep, that was my mistake. I'll fix it up in the repo for that tool now and maybe improve it a little too! :) Christian
On Sun, Nov 15, 2020 at 11:36:39AM +0100, Christian Brauner wrote: > Hey everyone, > > This is v2. It is reworked according to the reviews coming from > Christoph and others to adapt all relevant helpers and inode_operations > methods to account for idmapped mounts instead of introducing new > helpers and methods specific to idmapped mounts like we did before. > We've also moved the overlayfs conversion to handle idmapped mounts into > a separate patchset that will be sent out separately after the core > changes. The converted filesytems in this series include fat and ext4. > The config option to disable idmapped mounts has been moved from a a vfs > config ption to a per-filesystem option. They default to off. Having a > config option allows us to gain some confidence in the patchset over > multiple kernel releases. So uh I noticed that the new user_ns parameter passed to the xfs functions don't actually get used for anything. Did I miss something when I pulled the branch, or does this simply reflect xfs not having any idmap support? And how would one add such a thing? Replace the &init_user_ns with the passed-in user_ns parameter? > There are two noteable things about this version. First, that it comes > with a really large test-suite to test current vfs behavior and > idmapped mounts behavior. We intend this test-suite to grow over time > and at some point cover most basic core vfs functionality that isn't > covered in xfstests and have it be part of the selftests. Please put enough of a test in fstests to do basic validation that we filesystem developers didn't accidentally screw things up. --D > Second, while while working on adapting this patchset to the requested > changes, the runC and containerd crowd was nice enough to adapt > containerd to this patchset to make use of idmapped mounts in one of the > most widely used container runtimes: > https://github.com/containerd/containerd/pull/4734 > > With this patchset we make it possible to attach idmappings to bind > mounts. This handles several common use-cases. Here are just a few: > - Shifting of a container rootfs or base image without having to mangle > every file (runc, Docker, containerd, k8s, LXD, systemd ...) > - Sharing of data between host or privileged containers with > underprivileged containers (runc, Docker, containerd, k8s, LXD, ...) > - Shifting of subset of ownership-less filesystems (vfat) for use by > multiple users, effectively allowing for DAC on such devices (systemd, > Android, ...) > - Data sharing between multiple user namespaces with incompatible maps > (LXD, k8s, ...) > Making it possible to share directories and mounts between users with > different uids and gids is itself quite an important use-case in > distributed systems environments. It's of course especially useful in > general for portable usb sticks, sharing data between multiple users in > general, and sharing home directories between multiple users. The last > example is now elegantly expressed in systemd's homed concept for > portable home directories. As mentioned above, idmapped mounts also > allow data from the host to be shared with unprivileged containers, > between privileged and unprivileged containers simultaneously and in > addition also between unprivileged containers with different idmappings > whenever they are used to isolate one container completely from another > container. > As can be seen from answers to earlier threads of this patchset and from > the list of potential users interest in this patchset is fairly > widespread. > > We have implemented and proposed multiple solutions to this before. This > included the introduction of fsid mappings, a tiny filesystem that is > currently carried in Ubuntu that has shown it's limitations, and an > approach to call override creds in the vfs. None of these solutions have > covered all of the above use-cases. Some of them have been fairly hacky > too by e.g. violating how things should be passed down to the individual > filesystems. > The solution proposed here has it's origins in multiple discussions > during Linux Plumbers 2017 during and after the end of the containers > microconference. > To the best of my knowledge this involved Aleksa, Stéphane, Eric, David, > James, and myself. The original idea or a variant thereof has been > discussed, again to the best of my knowledge, after a Linux conference > in St. Petersburg in Russia in 2017 between Christoph, Tycho, and > myself. > We've taken the time to implement a working version of this solution > over the last weeks to the best of my abilities. Tycho has signed up > for this sligthly crazy endeavour as well and he has helped with the > conversion of the xattr codepaths and will be involved with others in > converting additional filesystems. > > This series makes idmappings a property of struct vfsmount instead of > tying it to a process being inside of a user namespace which has been > the case for all other proposed approaches. It also allows to pass down > the user namespace into the filesystms which is a clean way instead of > violating calling conventions by strapping the user namespace > information that is a property of the mount to the caller's credentials > or similar hacks. > With this idmappings become a property of bind-mounts, i.e. each > bind-mount can have a separate idmapping. Such idmapped mounts can even > be created inside of the initial user namespace. > > The vfsmount struct gains a new struct user_namespace member. The > idmapping of the user namespace becomes the idmapping of the mount. A > caller that is privileged with respect to the user namespace of > the superblock of the underlying filesystem can create an idmapped > bind-mount. In the future, we can enable unprivileged use-cases by > checking whether the caller is privileged wrt to the user namespace an > already idmapped mount has been marked with, allowing them to change the > idmapping. For now, keep things simple until we feel sure enough. Note, > that with syscall interception it is already possible to intercept > idmapped mount requests from unprivileged containers and handle them in > a sufficiently privileged container manager. Support for this is > already available in LXD and will be available in runC were syscall > interception is currently becoming part of the runtime spec (see > https://github.com/opencontainers/runtime-spec/pull/1074). > > The user namespace the mount will be marked with can be specified by > passing a file descriptor refering to the user namespace as an argument > to the new mount_setattr() syscall together with the new > MOUNT_ATTR_IDMAP flag. By default vfsmounts are marked with the initial > user namespace and no behavioral or performance changes should be > observed. All mapping operations are nops for the initial user > namespace. When a file/inode is accessed through an idmapped mount the > i_uid and i_gid of the inode will be remapped according to the user > namespace the mount has been marked with. > > In order to support idmapped mounts, filesystems need to be changed and > mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The initial > version contains fat and ext4 including a list of examples. But patches > for other filesystems are actively worked on but will be sent out > separately. We are here to see this through and there are multiple > people involved in converting filesystems. So filesystem developers are > not left alone with this. > > I have written a simple tool available at > https://github.com/brauner/mount-idmapped that allows to create idmapped > mounts so people can play with this patch series. Here are a few > illustrations: > > 1. Create a simple idmapped mount of another user's home directory > > u1001@f2-vm:/$ sudo ./mount-idmapped --map-mount b:1000:1001:1 /home/ubuntu/ /mnt > u1001@f2-vm:/$ ls -al /home/ubuntu/ > total 28 > drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 . > drwxr-xr-x 4 root root 4096 Oct 28 04:00 .. > -rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history > -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout > -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc > -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile > -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful > -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo > u1001@f2-vm:/$ ls -al /mnt/ > total 28 > drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 . > drwxr-xr-x 29 root root 4096 Oct 28 22:01 .. > -rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history > -rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout > -rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc > -rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile > -rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful > -rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo > u1001@f2-vm:/$ touch /mnt/my-file > u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file > u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file > u1001@f2-vm:/$ ls -al /mnt/my-file > -rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file > u1001@f2-vm:/$ ls -al /home/ubuntu/my-file > -rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file > u1001@f2-vm:/$ getfacl /mnt/my-file > getfacl: Removing leading '/' from absolute path names > # file: mnt/my-file > # owner: u1001 > # group: u1001 > user::rw- > user:u1001:rwx > group::rw- > mask::rwx > other::r-- > u1001@f2-vm:/$ getfacl /home/ubuntu/my-file > getfacl: Removing leading '/' from absolute path names > # file: home/ubuntu/my-file > # owner: ubuntu > # group: ubuntu > user::rw- > user:ubuntu:rwx > group::rw- > mask::rwx > other::r-- > > 2. Create mapping of the whole ext4 rootfs without a mapping for uid and gid 0 > > ubuntu@f2-vm:~$ sudo /mount-idmapped --map-mount b:1:1:65536 / /mnt/ > ubuntu@f2-vm:~$ findmnt | grep mnt > └─/mnt /dev/sda2 ext4 rw,relatime > └─/mnt/mnt /dev/sda2 ext4 rw,relatime > ubuntu@f2-vm:~$ sudo mkdir /AS-ROOT-CAN-CREATE > ubuntu@f2-vm:~$ sudo mkdir /mnt/AS-ROOT-CANT-CREATE > mkdir: cannot create directory ‘/mnt/AS-ROOT-CANT-CREATE’: Value too large for defined data type > ubuntu@f2-vm:~$ mkdir /mnt/home/ubuntu/AS-USER-1000-CAN-CREATE > > 3. Create a vfat usb mount and expose to user 1001 and 5000 > > ubuntu@f2-vm:/$ sudo mount /dev/sdb /mnt > ubuntu@f2-vm:/$ findmnt | grep mnt > └─/mnt /dev/sdb vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro > ubuntu@f2-vm:/$ ls -al /mnt > total 12 > drwxr-xr-x 2 root root 4096 Jan 1 1970 . > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > -rwxr-xr-x 1 root root 4 Oct 28 03:44 aaa > -rwxr-xr-x 1 root root 0 Oct 28 01:09 bbb > ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:1001:1 /mnt /mnt-1001/ > ubuntu@f2-vm:/$ ls -al /mnt-1001/ > total 12 > drwxr-xr-x 2 u1001 u1001 4096 Jan 1 1970 . > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > -rwxr-xr-x 1 u1001 u1001 4 Oct 28 03:44 aaa > -rwxr-xr-x 1 u1001 u1001 0 Oct 28 01:09 bbb > ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:5000:1 /mnt /mnt-5000/ > ubuntu@f2-vm:/$ ls -al /mnt-5000/ > total 12 > drwxr-xr-x 2 5000 5000 4096 Jan 1 1970 . > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > -rwxr-xr-x 1 5000 5000 4 Oct 28 03:44 aaa > -rwxr-xr-x 1 5000 5000 0 Oct 28 01:09 bbb > > 4. Create an idmapped rootfs mount for a container > > root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/ > total 68 > drwxr-xr-x 17 20000 20000 4096 Sep 24 07:48 . > drwxrwx--- 3 20000 20000 4096 Oct 16 19:26 .. > lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 bin -> usr/bin > drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 boot > drwxr-xr-x 3 20000 20000 4096 Oct 16 19:26 dev > drwxr-xr-x 61 20000 20000 4096 Oct 16 19:26 etc > drwxr-xr-x 3 20000 20000 4096 Sep 24 07:45 home > lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 lib -> usr/lib > lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib32 -> usr/lib32 > lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib64 -> usr/lib64 > lrwxrwxrwx 1 20000 20000 10 Sep 24 07:43 libx32 -> usr/libx32 > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 media > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 mnt > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 opt > drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 proc > drwx------ 2 20000 20000 4096 Sep 24 07:43 root > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:45 run > lrwxrwxrwx 1 20000 20000 8 Sep 24 07:43 sbin -> usr/sbin > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 srv > drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 sys > drwxrwxrwt 2 20000 20000 4096 Sep 24 07:44 tmp > drwxr-xr-x 13 20000 20000 4096 Sep 24 07:43 usr > drwxr-xr-x 12 20000 20000 4096 Sep 24 07:44 var > root@f2-vm:~# /mount-idmapped --map-mount b:20000:10000:100000 /var/lib/lxc/f2/rootfs/ /mnt > root@f2-vm:~# ls -al /mnt > total 68 > drwxr-xr-x 17 10000 10000 4096 Sep 24 07:48 . > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 bin -> usr/bin > drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 boot > drwxr-xr-x 3 10000 10000 4096 Oct 16 19:26 dev > drwxr-xr-x 61 10000 10000 4096 Oct 16 19:26 etc > drwxr-xr-x 3 10000 10000 4096 Sep 24 07:45 home > lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 lib -> usr/lib > lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib32 -> usr/lib32 > lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib64 -> usr/lib64 > lrwxrwxrwx 1 10000 10000 10 Sep 24 07:43 libx32 -> usr/libx32 > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 media > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 mnt > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 opt > drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 proc > drwx------ 2 10000 10000 4096 Sep 24 07:43 root > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:45 run > lrwxrwxrwx 1 10000 10000 8 Sep 24 07:43 sbin -> usr/sbin > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 srv > drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 sys > drwxrwxrwt 2 10000 10000 4096 Sep 24 07:44 tmp > drwxr-xr-x 13 10000 10000 4096 Sep 24 07:43 usr > drwxr-xr-x 12 10000 10000 4096 Sep 24 07:44 var > root@f2-vm:~# lxc-start f2 # uses /mnt as rootfs > root@f2-vm:~# lxc-attach f2 -- cat /proc/1/uid_map > 0 10000 10000 > root@f2-vm:~# lxc-attach f2 -- cat /proc/1/gid_map > 0 10000 10000 > root@f2-vm:~# lxc-attach f2 -- ls -al / > total 52 > drwxr-xr-x 17 root root 4096 Sep 24 07:48 . > drwxr-xr-x 17 root root 4096 Sep 24 07:48 .. > lrwxrwxrwx 1 root root 7 Sep 24 07:43 bin -> usr/bin > drwxr-xr-x 2 root root 4096 Apr 15 2020 boot > drwxr-xr-x 5 root root 500 Oct 28 23:39 dev > drwxr-xr-x 61 root root 4096 Oct 28 23:39 etc > drwxr-xr-x 3 root root 4096 Sep 24 07:45 home > lrwxrwxrwx 1 root root 7 Sep 24 07:43 lib -> usr/lib > lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib32 -> usr/lib32 > lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib64 -> usr/lib64 > lrwxrwxrwx 1 root root 10 Sep 24 07:43 libx32 -> usr/libx32 > drwxr-xr-x 2 root root 4096 Sep 24 07:43 media > drwxr-xr-x 2 root root 4096 Sep 24 07:43 mnt > drwxr-xr-x 2 root root 4096 Sep 24 07:43 opt > dr-xr-xr-x 232 nobody nogroup 0 Oct 28 23:39 proc > drwx------ 2 root root 4096 Oct 28 23:41 root > drwxr-xr-x 12 root root 360 Oct 28 23:39 run > lrwxrwxrwx 1 root root 8 Sep 24 07:43 sbin -> usr/sbin > drwxr-xr-x 2 root root 4096 Sep 24 07:43 srv > dr-xr-xr-x 13 nobody nogroup 0 Oct 28 23:39 sys > drwxrwxrwt 11 root root 4096 Oct 28 23:40 tmp > drwxr-xr-x 13 root root 4096 Sep 24 07:43 usr > drwxr-xr-x 12 root root 4096 Sep 24 07:44 var > root@f2-vm:~# lxc-attach f2 -- ls -al /my-file > -rw-r--r-- 1 root root 0 Oct 28 23:43 /my-file > root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/my-file > -rw-r--r-- 1 20000 20000 0 Oct 28 23:43 /var/lib/lxc/f2/rootfs/my-file > > I'd like to say thanks to: > Al for pointing me into the direction to avoid inode alias issues during > lookup. David for various discussions around this. Christoph for proving > a first proper review and for being involved in the original idea. Tycho > for helping with this series and on future patches to convert > filesystems. Alban Crequy and the Kinvolk located just a few streets > away from me in Berlin for providing use-case discussions and writing > patches for containerd! Stéphane for his invaluable input on many things > and level head and enabling me to work on this. Amir for explaining and > discussing aspects of overlayfs with me. I'd like to especially thank > Seth Forshee because he provided a lot of good analysis, suggestions, > and participated in short-notice discussions in both chat and video for > some nitty-gritty technical details. > > This series can be found and pulled from the three usual locations: > https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git/log/?h=idmapped_mounts > https://github.com/brauner/linux/tree/idmapped_mounts > https://gitlab.com/brauner/linux/-/commits/idmapped_mounts > > Thanks! > Christian > > Christian Brauner (37): > namespace: take lock_mount_hash() directly when changing flags > mount: make {lock,unlock}_mount_hash() static > namespace: only take read lock in do_reconfigure_mnt() > fs: add mount_setattr() > tests: add mount_setattr() selftests > fs: add id translation helpers > mount: attach mappings to mounts > capability: handle idmapped mounts > namei: add idmapped mount aware permission helpers > inode: add idmapped mount aware init and permission helpers > attr: handle idmapped mounts > acl: handle idmapped mounts > commoncap: handle idmapped mounts > stat: handle idmapped mounts > namei: handle idmapped mounts in may_*() helpers > namei: introduce struct renamedata > namei: prepare for idmapped mounts > open: handle idmapped mounts in do_truncate() > open: handle idmapped mounts > af_unix: handle idmapped mounts > utimes: handle idmapped mounts > fcntl: handle idmapped mounts > notify: handle idmapped mounts > init: handle idmapped mounts > ioctl: handle idmapped mounts > would_dump: handle idmapped mounts > exec: handle idmapped mounts > fs: add helpers for idmap mounts > apparmor: handle idmapped mounts > audit: handle idmapped mounts > ima: handle idmapped mounts > fat: handle idmapped mounts > ext4: support idmapped mounts > ecryptfs: do not mount on top of idmapped mounts > overlayfs: do not mount on top of idmapped mounts > fs: introduce MOUNT_ATTR_IDMAP > tests: add vfs/idmapped mounts test suite > > Tycho Andersen (2): > xattr: handle idmapped mounts > selftests: add idmapped mounts xattr selftest > > Documentation/filesystems/locking.rst | 6 +- > Documentation/filesystems/porting.rst | 2 + > Documentation/filesystems/vfs.rst | 17 +- > arch/alpha/kernel/syscalls/syscall.tbl | 1 + > arch/arm/tools/syscall.tbl | 1 + > arch/arm64/include/asm/unistd32.h | 2 + > arch/ia64/kernel/syscalls/syscall.tbl | 1 + > arch/m68k/kernel/syscalls/syscall.tbl | 1 + > arch/microblaze/kernel/syscalls/syscall.tbl | 1 + > arch/mips/kernel/syscalls/syscall_n32.tbl | 1 + > arch/mips/kernel/syscalls/syscall_n64.tbl | 1 + > arch/mips/kernel/syscalls/syscall_o32.tbl | 1 + > arch/parisc/kernel/syscalls/syscall.tbl | 1 + > arch/powerpc/kernel/syscalls/syscall.tbl | 1 + > arch/powerpc/platforms/cell/spufs/inode.c | 5 +- > arch/s390/kernel/syscalls/syscall.tbl | 1 + > arch/sh/kernel/syscalls/syscall.tbl | 1 + > arch/sparc/kernel/syscalls/syscall.tbl | 1 + > arch/x86/entry/syscalls/syscall_32.tbl | 1 + > arch/x86/entry/syscalls/syscall_64.tbl | 1 + > arch/xtensa/kernel/syscalls/syscall.tbl | 1 + > drivers/android/binderfs.c | 3 +- > drivers/base/devtmpfs.c | 12 +- > fs/9p/acl.c | 7 +- > fs/9p/v9fs.h | 3 +- > fs/9p/v9fs_vfs.h | 2 +- > fs/9p/vfs_inode.c | 32 +- > fs/9p/vfs_inode_dotl.c | 34 +- > fs/9p/xattr.c | 1 + > fs/adfs/adfs.h | 3 +- > fs/adfs/inode.c | 5 +- > fs/affs/affs.h | 10 +- > fs/affs/inode.c | 7 +- > fs/affs/namei.c | 15 +- > fs/afs/dir.c | 34 +- > fs/afs/inode.c | 5 +- > fs/afs/internal.h | 4 +- > fs/afs/security.c | 2 +- > fs/afs/xattr.c | 2 + > fs/attr.c | 78 +- > fs/autofs/root.c | 13 +- > fs/bad_inode.c | 31 +- > fs/bfs/dir.c | 12 +- > fs/btrfs/acl.c | 5 +- > fs/btrfs/ctree.h | 3 +- > fs/btrfs/inode.c | 41 +- > fs/btrfs/ioctl.c | 25 +- > fs/btrfs/tests/btrfs-tests.c | 2 +- > fs/btrfs/xattr.c | 2 + > fs/cachefiles/interface.c | 4 +- > fs/cachefiles/namei.c | 19 +- > fs/cachefiles/xattr.c | 16 +- > fs/ceph/acl.c | 5 +- > fs/ceph/dir.c | 23 +- > fs/ceph/inode.c | 13 +- > fs/ceph/super.h | 8 +- > fs/ceph/xattr.c | 1 + > fs/cifs/cifsfs.c | 4 +- > fs/cifs/cifsfs.h | 18 +- > fs/cifs/dir.c | 8 +- > fs/cifs/inode.c | 22 +- > fs/cifs/link.c | 3 +- > fs/cifs/xattr.c | 1 + > fs/coda/coda_linux.h | 4 +- > fs/coda/dir.c | 18 +- > fs/coda/inode.c | 5 +- > fs/coda/pioctl.c | 6 +- > fs/configfs/configfs_internal.h | 7 +- > fs/configfs/dir.c | 3 +- > fs/configfs/inode.c | 5 +- > fs/configfs/symlink.c | 5 +- > fs/coredump.c | 12 +- > fs/crypto/policy.c | 2 +- > fs/debugfs/inode.c | 9 +- > fs/ecryptfs/crypto.c | 4 +- > fs/ecryptfs/inode.c | 74 +- > fs/ecryptfs/main.c | 6 + > fs/ecryptfs/mmap.c | 4 +- > fs/efivarfs/file.c | 2 +- > fs/efivarfs/inode.c | 4 +- > fs/erofs/inode.c | 2 +- > fs/exec.c | 12 +- > fs/exfat/exfat_fs.h | 3 +- > fs/exfat/file.c | 9 +- > fs/exfat/namei.c | 13 +- > fs/ext2/acl.c | 5 +- > fs/ext2/acl.h | 3 +- > fs/ext2/ext2.h | 2 +- > fs/ext2/ialloc.c | 2 +- > fs/ext2/inode.c | 11 +- > fs/ext2/ioctl.c | 6 +- > fs/ext2/namei.c | 22 +- > fs/ext2/xattr_security.c | 1 + > fs/ext2/xattr_trusted.c | 1 + > fs/ext2/xattr_user.c | 1 + > fs/ext4/Kconfig | 9 + > fs/ext4/acl.c | 5 +- > fs/ext4/acl.h | 3 +- > fs/ext4/ext4.h | 15 +- > fs/ext4/ialloc.c | 7 +- > fs/ext4/inode.c | 14 +- > fs/ext4/ioctl.c | 18 +- > fs/ext4/namei.c | 52 +- > fs/ext4/super.c | 6 +- > fs/ext4/xattr_hurd.c | 1 + > fs/ext4/xattr_security.c | 1 + > fs/ext4/xattr_trusted.c | 1 + > fs/ext4/xattr_user.c | 1 + > fs/f2fs/acl.c | 5 +- > fs/f2fs/acl.h | 3 +- > fs/f2fs/f2fs.h | 3 +- > fs/f2fs/file.c | 23 +- > fs/f2fs/namei.c | 26 +- > fs/f2fs/xattr.c | 4 +- > fs/fat/fat.h | 3 +- > fs/fat/file.c | 20 +- > fs/fat/namei_msdos.c | 15 +- > fs/fat/namei_vfat.c | 15 +- > fs/fcntl.c | 3 +- > fs/fuse/acl.c | 3 +- > fs/fuse/dir.c | 41 +- > fs/fuse/fuse_i.h | 4 +- > fs/fuse/xattr.c | 2 + > fs/gfs2/acl.c | 5 +- > fs/gfs2/acl.h | 3 +- > fs/gfs2/file.c | 4 +- > fs/gfs2/inode.c | 54 +- > fs/gfs2/inode.h | 2 +- > fs/gfs2/xattr.c | 1 + > fs/hfs/attr.c | 1 + > fs/hfs/dir.c | 13 +- > fs/hfs/hfs_fs.h | 2 +- > fs/hfs/inode.c | 7 +- > fs/hfsplus/dir.c | 25 +- > fs/hfsplus/inode.c | 11 +- > fs/hfsplus/ioctl.c | 2 +- > fs/hfsplus/xattr.c | 1 + > fs/hfsplus/xattr_security.c | 1 + > fs/hfsplus/xattr_trusted.c | 1 + > fs/hfsplus/xattr_user.c | 1 + > fs/hostfs/hostfs_kern.c | 31 +- > fs/hpfs/hpfs_fn.h | 2 +- > fs/hpfs/inode.c | 7 +- > fs/hpfs/namei.c | 20 +- > fs/hugetlbfs/inode.c | 31 +- > fs/init.c | 21 +- > fs/inode.c | 38 +- > fs/internal.h | 9 + > fs/jffs2/acl.c | 5 +- > fs/jffs2/acl.h | 3 +- > fs/jffs2/dir.c | 32 +- > fs/jffs2/fs.c | 7 +- > fs/jffs2/os-linux.h | 2 +- > fs/jffs2/security.c | 1 + > fs/jffs2/xattr_trusted.c | 1 + > fs/jffs2/xattr_user.c | 1 + > fs/jfs/acl.c | 5 +- > fs/jfs/file.c | 9 +- > fs/jfs/ioctl.c | 2 +- > fs/jfs/jfs_acl.h | 3 +- > fs/jfs/jfs_inode.c | 2 +- > fs/jfs/jfs_inode.h | 2 +- > fs/jfs/namei.c | 21 +- > fs/jfs/xattr.c | 2 + > fs/kernfs/dir.c | 7 +- > fs/kernfs/inode.c | 15 +- > fs/kernfs/kernfs-internal.h | 5 +- > fs/libfs.c | 20 +- > fs/minix/bitmap.c | 2 +- > fs/minix/file.c | 7 +- > fs/minix/inode.c | 2 +- > fs/minix/namei.c | 25 +- > fs/mount.h | 10 - > fs/namei.c | 317 +- > fs/namespace.c | 473 ++- > fs/nfs/dir.c | 23 +- > fs/nfs/inode.c | 5 +- > fs/nfs/internal.h | 10 +- > fs/nfs/namespace.c | 7 +- > fs/nfs/nfs3_fs.h | 3 +- > fs/nfs/nfs3acl.c | 3 +- > fs/nfs/nfs4proc.c | 3 + > fs/nfsd/nfs2acl.c | 4 +- > fs/nfsd/nfs3acl.c | 4 +- > fs/nfsd/nfs4acl.c | 4 +- > fs/nfsd/nfs4recover.c | 6 +- > fs/nfsd/nfsfh.c | 2 +- > fs/nfsd/nfsproc.c | 2 +- > fs/nfsd/vfs.c | 47 +- > fs/nilfs2/inode.c | 13 +- > fs/nilfs2/ioctl.c | 2 +- > fs/nilfs2/namei.c | 20 +- > fs/nilfs2/nilfs.h | 4 +- > fs/notify/fanotify/fanotify_user.c | 2 +- > fs/notify/inotify/inotify_user.c | 3 +- > fs/ntfs/inode.c | 2 +- > fs/ocfs2/acl.c | 5 +- > fs/ocfs2/acl.h | 3 +- > fs/ocfs2/dlmfs/dlmfs.c | 17 +- > fs/ocfs2/file.c | 13 +- > fs/ocfs2/file.h | 5 +- > fs/ocfs2/ioctl.c | 2 +- > fs/ocfs2/namei.c | 21 +- > fs/ocfs2/refcounttree.c | 4 +- > fs/ocfs2/xattr.c | 3 + > fs/omfs/dir.c | 13 +- > fs/omfs/file.c | 7 +- > fs/omfs/inode.c | 2 +- > fs/open.c | 52 +- > fs/orangefs/acl.c | 5 +- > fs/orangefs/inode.c | 15 +- > fs/orangefs/namei.c | 12 +- > fs/orangefs/orangefs-kernel.h | 7 +- > fs/orangefs/xattr.c | 1 + > fs/overlayfs/copy_up.c | 20 +- > fs/overlayfs/dir.c | 31 +- > fs/overlayfs/file.c | 6 +- > fs/overlayfs/inode.c | 21 +- > fs/overlayfs/overlayfs.h | 40 +- > fs/overlayfs/super.c | 27 +- > fs/overlayfs/util.c | 4 +- > fs/posix_acl.c | 78 +- > fs/proc/base.c | 24 +- > fs/proc/fd.c | 4 +- > fs/proc/fd.h | 3 +- > fs/proc/generic.c | 9 +- > fs/proc/internal.h | 2 +- > fs/proc/proc_net.c | 2 +- > fs/proc/proc_sysctl.c | 12 +- > fs/proc/root.c | 2 +- > fs/proc_namespace.c | 1 + > fs/ramfs/file-nommu.c | 9 +- > fs/ramfs/inode.c | 18 +- > fs/reiserfs/acl.h | 3 +- > fs/reiserfs/inode.c | 7 +- > fs/reiserfs/ioctl.c | 4 +- > fs/reiserfs/namei.c | 21 +- > fs/reiserfs/reiserfs.h | 3 +- > fs/reiserfs/xattr.c | 12 +- > fs/reiserfs/xattr.h | 2 +- > fs/reiserfs/xattr_acl.c | 7 +- > fs/reiserfs/xattr_security.c | 3 +- > fs/reiserfs/xattr_trusted.c | 3 +- > fs/reiserfs/xattr_user.c | 3 +- > fs/remap_range.c | 7 +- > fs/stat.c | 10 +- > fs/sysv/file.c | 7 +- > fs/sysv/ialloc.c | 2 +- > fs/sysv/itree.c | 2 +- > fs/sysv/namei.c | 21 +- > fs/tracefs/inode.c | 4 +- > fs/ubifs/dir.c | 29 +- > fs/ubifs/file.c | 5 +- > fs/ubifs/ioctl.c | 2 +- > fs/ubifs/ubifs.h | 3 +- > fs/ubifs/xattr.c | 1 + > fs/udf/file.c | 9 +- > fs/udf/ialloc.c | 2 +- > fs/udf/namei.c | 24 +- > fs/udf/symlink.c | 2 +- > fs/ufs/ialloc.c | 2 +- > fs/ufs/inode.c | 7 +- > fs/ufs/namei.c | 19 +- > fs/ufs/ufs.h | 3 +- > fs/utimes.c | 4 +- > fs/vboxsf/dir.c | 12 +- > fs/vboxsf/utils.c | 5 +- > fs/vboxsf/vfsmod.h | 3 +- > fs/verity/enable.c | 2 +- > fs/xattr.c | 136 +- > fs/xfs/xfs_acl.c | 5 +- > fs/xfs/xfs_acl.h | 3 +- > fs/xfs/xfs_ioctl.c | 4 +- > fs/xfs/xfs_iops.c | 55 +- > fs/xfs/xfs_xattr.c | 3 +- > fs/zonefs/super.c | 9 +- > include/linux/audit.h | 10 +- > include/linux/capability.h | 14 +- > include/linux/fs.h | 145 +- > include/linux/ima.h | 15 +- > include/linux/lsm_hook_defs.h | 15 +- > include/linux/lsm_hooks.h | 1 + > include/linux/mount.h | 14 +- > include/linux/nfs_fs.h | 4 +- > include/linux/posix_acl.h | 15 +- > include/linux/posix_acl_xattr.h | 12 +- > include/linux/security.h | 44 +- > include/linux/syscalls.h | 3 + > include/linux/xattr.h | 30 +- > include/uapi/asm-generic/unistd.h | 4 +- > include/uapi/linux/mount.h | 25 + > ipc/mqueue.c | 16 +- > kernel/auditsc.c | 29 +- > kernel/bpf/inode.c | 13 +- > kernel/capability.c | 14 +- > kernel/cgroup/cgroup.c | 2 +- > kernel/sys.c | 2 +- > mm/madvise.c | 4 +- > mm/memcontrol.c | 2 +- > mm/mincore.c | 4 +- > mm/shmem.c | 45 +- > net/socket.c | 6 +- > net/unix/af_unix.c | 4 +- > security/apparmor/apparmorfs.c | 3 +- > security/apparmor/domain.c | 13 +- > security/apparmor/file.c | 5 +- > security/apparmor/lsm.c | 12 +- > security/commoncap.c | 46 +- > security/integrity/evm/evm_crypto.c | 11 +- > security/integrity/evm/evm_main.c | 4 +- > security/integrity/evm/evm_secfs.c | 2 +- > security/integrity/ima/ima.h | 19 +- > security/integrity/ima/ima_api.c | 10 +- > security/integrity/ima/ima_appraise.c | 22 +- > security/integrity/ima/ima_asymmetric_keys.c | 2 +- > security/integrity/ima/ima_main.c | 28 +- > security/integrity/ima/ima_policy.c | 17 +- > security/integrity/ima/ima_queue_keys.c | 2 +- > security/security.c | 25 +- > security/selinux/hooks.c | 22 +- > security/smack/smack_lsm.c | 18 +- > tools/include/uapi/asm-generic/unistd.h | 4 +- > tools/testing/selftests/Makefile | 1 + > .../testing/selftests/idmap_mounts/.gitignore | 2 + > tools/testing/selftests/idmap_mounts/Makefile | 12 + > tools/testing/selftests/idmap_mounts/config | 1 + > tools/testing/selftests/idmap_mounts/core.c | 3476 +++++++++++++++++ > .../testing/selftests/idmap_mounts/internal.h | 127 + > tools/testing/selftests/idmap_mounts/utils.c | 136 + > tools/testing/selftests/idmap_mounts/utils.h | 17 + > tools/testing/selftests/idmap_mounts/xattr.c | 172 + > .../selftests/mount_setattr/.gitignore | 1 + > .../testing/selftests/mount_setattr/Makefile | 7 + > tools/testing/selftests/mount_setattr/config | 1 + > .../mount_setattr/mount_setattr_test.c | 889 +++++ > 335 files changed, 7594 insertions(+), 1570 deletions(-) > create mode 100644 tools/testing/selftests/idmap_mounts/.gitignore > create mode 100644 tools/testing/selftests/idmap_mounts/Makefile > create mode 100644 tools/testing/selftests/idmap_mounts/config > create mode 100644 tools/testing/selftests/idmap_mounts/core.c > create mode 100644 tools/testing/selftests/idmap_mounts/internal.h > create mode 100644 tools/testing/selftests/idmap_mounts/utils.c > create mode 100644 tools/testing/selftests/idmap_mounts/utils.h > create mode 100644 tools/testing/selftests/idmap_mounts/xattr.c > create mode 100644 tools/testing/selftests/mount_setattr/.gitignore > create mode 100644 tools/testing/selftests/mount_setattr/Makefile > create mode 100644 tools/testing/selftests/mount_setattr/config > create mode 100644 tools/testing/selftests/mount_setattr/mount_setattr_test.c > > > base-commit: 3cea11cd5e3b00d91caf0b4730194039b45c5891 > -- > 2.29.2 >
On Thu, Nov 19, 2020 at 06:33:09PM -0800, Darrick J. Wong wrote: > On Sun, Nov 15, 2020 at 11:36:39AM +0100, Christian Brauner wrote: > > Hey everyone, > > > > This is v2. It is reworked according to the reviews coming from > > Christoph and others to adapt all relevant helpers and inode_operations > > methods to account for idmapped mounts instead of introducing new > > helpers and methods specific to idmapped mounts like we did before. > > We've also moved the overlayfs conversion to handle idmapped mounts into > > a separate patchset that will be sent out separately after the core > > changes. The converted filesytems in this series include fat and ext4. > > The config option to disable idmapped mounts has been moved from a a vfs > > config ption to a per-filesystem option. They default to off. Having a > > config option allows us to gain some confidence in the patchset over > > multiple kernel releases. > > So uh I noticed that the new user_ns parameter passed to the xfs > functions don't actually get used for anything. Did I miss something > when I pulled the branch, or does this simply reflect xfs not having any > idmap support? And how would one add such a thing? Replace the > &init_user_ns with the passed-in user_ns parameter? Sorry, maybe you missed it but that's mentioned further below in the commit messages: "In order to support idmapped mounts, filesystems need to be changed and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The initial version contains fat and ext4 including a list of examples. But patches for other filesystems are actively worked on but will be sent out separately. We are here to see this through and there are multiple people involved in converting filesystems. So filesystem developers are not left alone with this." > > > There are two noteable things about this version. First, that it comes > > with a really large test-suite to test current vfs behavior and > > idmapped mounts behavior. We intend this test-suite to grow over time > > and at some point cover most basic core vfs functionality that isn't > > covered in xfstests and have it be part of the selftests. > > Please put enough of a test in fstests to do basic validation that we > filesystem developers didn't accidentally screw things up. Maybe you didn't see this or you're referring to xfstests but this series contains a >=4000 lines long test-suite that validates all core features with and without idmapped mounts. It's the last patch in this version of the series and it's located in: tools/testing/selftests/idmap_mounts. Everytime a filesystem is added this test-suite will be updated. We would perfer if this test would be shipped with the kernel itself and not in a separate test-suite such as xfstests. But we're happy to add patches for the latter at some point too. Christian > > --D > > > Second, while while working on adapting this patchset to the requested > > changes, the runC and containerd crowd was nice enough to adapt > > containerd to this patchset to make use of idmapped mounts in one of the > > most widely used container runtimes: > > https://github.com/containerd/containerd/pull/4734 > > > > With this patchset we make it possible to attach idmappings to bind > > mounts. This handles several common use-cases. Here are just a few: > > - Shifting of a container rootfs or base image without having to mangle > > every file (runc, Docker, containerd, k8s, LXD, systemd ...) > > - Sharing of data between host or privileged containers with > > underprivileged containers (runc, Docker, containerd, k8s, LXD, ...) > > - Shifting of subset of ownership-less filesystems (vfat) for use by > > multiple users, effectively allowing for DAC on such devices (systemd, > > Android, ...) > > - Data sharing between multiple user namespaces with incompatible maps > > (LXD, k8s, ...) > > Making it possible to share directories and mounts between users with > > different uids and gids is itself quite an important use-case in > > distributed systems environments. It's of course especially useful in > > general for portable usb sticks, sharing data between multiple users in > > general, and sharing home directories between multiple users. The last > > example is now elegantly expressed in systemd's homed concept for > > portable home directories. As mentioned above, idmapped mounts also > > allow data from the host to be shared with unprivileged containers, > > between privileged and unprivileged containers simultaneously and in > > addition also between unprivileged containers with different idmappings > > whenever they are used to isolate one container completely from another > > container. > > As can be seen from answers to earlier threads of this patchset and from > > the list of potential users interest in this patchset is fairly > > widespread. > > > > We have implemented and proposed multiple solutions to this before. This > > included the introduction of fsid mappings, a tiny filesystem that is > > currently carried in Ubuntu that has shown it's limitations, and an > > approach to call override creds in the vfs. None of these solutions have > > covered all of the above use-cases. Some of them have been fairly hacky > > too by e.g. violating how things should be passed down to the individual > > filesystems. > > The solution proposed here has it's origins in multiple discussions > > during Linux Plumbers 2017 during and after the end of the containers > > microconference. > > To the best of my knowledge this involved Aleksa, Stéphane, Eric, David, > > James, and myself. The original idea or a variant thereof has been > > discussed, again to the best of my knowledge, after a Linux conference > > in St. Petersburg in Russia in 2017 between Christoph, Tycho, and > > myself. > > We've taken the time to implement a working version of this solution > > over the last weeks to the best of my abilities. Tycho has signed up > > for this sligthly crazy endeavour as well and he has helped with the > > conversion of the xattr codepaths and will be involved with others in > > converting additional filesystems. > > > > This series makes idmappings a property of struct vfsmount instead of > > tying it to a process being inside of a user namespace which has been > > the case for all other proposed approaches. It also allows to pass down > > the user namespace into the filesystms which is a clean way instead of > > violating calling conventions by strapping the user namespace > > information that is a property of the mount to the caller's credentials > > or similar hacks. > > With this idmappings become a property of bind-mounts, i.e. each > > bind-mount can have a separate idmapping. Such idmapped mounts can even > > be created inside of the initial user namespace. > > > > The vfsmount struct gains a new struct user_namespace member. The > > idmapping of the user namespace becomes the idmapping of the mount. A > > caller that is privileged with respect to the user namespace of > > the superblock of the underlying filesystem can create an idmapped > > bind-mount. In the future, we can enable unprivileged use-cases by > > checking whether the caller is privileged wrt to the user namespace an > > already idmapped mount has been marked with, allowing them to change the > > idmapping. For now, keep things simple until we feel sure enough. Note, > > that with syscall interception it is already possible to intercept > > idmapped mount requests from unprivileged containers and handle them in > > a sufficiently privileged container manager. Support for this is > > already available in LXD and will be available in runC were syscall > > interception is currently becoming part of the runtime spec (see > > https://github.com/opencontainers/runtime-spec/pull/1074). > > > > The user namespace the mount will be marked with can be specified by > > passing a file descriptor refering to the user namespace as an argument > > to the new mount_setattr() syscall together with the new > > MOUNT_ATTR_IDMAP flag. By default vfsmounts are marked with the initial > > user namespace and no behavioral or performance changes should be > > observed. All mapping operations are nops for the initial user > > namespace. When a file/inode is accessed through an idmapped mount the > > i_uid and i_gid of the inode will be remapped according to the user > > namespace the mount has been marked with. > > > > In order to support idmapped mounts, filesystems need to be changed and > > mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The initial > > version contains fat and ext4 including a list of examples. But patches > > for other filesystems are actively worked on but will be sent out > > separately. We are here to see this through and there are multiple > > people involved in converting filesystems. So filesystem developers are > > not left alone with this. > > > > I have written a simple tool available at > > https://github.com/brauner/mount-idmapped that allows to create idmapped > > mounts so people can play with this patch series. Here are a few > > illustrations: > > > > 1. Create a simple idmapped mount of another user's home directory > > > > u1001@f2-vm:/$ sudo ./mount-idmapped --map-mount b:1000:1001:1 /home/ubuntu/ /mnt > > u1001@f2-vm:/$ ls -al /home/ubuntu/ > > total 28 > > drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 . > > drwxr-xr-x 4 root root 4096 Oct 28 04:00 .. > > -rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history > > -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout > > -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc > > -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile > > -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful > > -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo > > u1001@f2-vm:/$ ls -al /mnt/ > > total 28 > > drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 . > > drwxr-xr-x 29 root root 4096 Oct 28 22:01 .. > > -rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history > > -rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout > > -rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc > > -rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile > > -rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful > > -rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo > > u1001@f2-vm:/$ touch /mnt/my-file > > u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file > > u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file > > u1001@f2-vm:/$ ls -al /mnt/my-file > > -rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file > > u1001@f2-vm:/$ ls -al /home/ubuntu/my-file > > -rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file > > u1001@f2-vm:/$ getfacl /mnt/my-file > > getfacl: Removing leading '/' from absolute path names > > # file: mnt/my-file > > # owner: u1001 > > # group: u1001 > > user::rw- > > user:u1001:rwx > > group::rw- > > mask::rwx > > other::r-- > > u1001@f2-vm:/$ getfacl /home/ubuntu/my-file > > getfacl: Removing leading '/' from absolute path names > > # file: home/ubuntu/my-file > > # owner: ubuntu > > # group: ubuntu > > user::rw- > > user:ubuntu:rwx > > group::rw- > > mask::rwx > > other::r-- > > > > 2. Create mapping of the whole ext4 rootfs without a mapping for uid and gid 0 > > > > ubuntu@f2-vm:~$ sudo /mount-idmapped --map-mount b:1:1:65536 / /mnt/ > > ubuntu@f2-vm:~$ findmnt | grep mnt > > └─/mnt /dev/sda2 ext4 rw,relatime > > └─/mnt/mnt /dev/sda2 ext4 rw,relatime > > ubuntu@f2-vm:~$ sudo mkdir /AS-ROOT-CAN-CREATE > > ubuntu@f2-vm:~$ sudo mkdir /mnt/AS-ROOT-CANT-CREATE > > mkdir: cannot create directory ‘/mnt/AS-ROOT-CANT-CREATE’: Value too large for defined data type > > ubuntu@f2-vm:~$ mkdir /mnt/home/ubuntu/AS-USER-1000-CAN-CREATE > > > > 3. Create a vfat usb mount and expose to user 1001 and 5000 > > > > ubuntu@f2-vm:/$ sudo mount /dev/sdb /mnt > > ubuntu@f2-vm:/$ findmnt | grep mnt > > └─/mnt /dev/sdb vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro > > ubuntu@f2-vm:/$ ls -al /mnt > > total 12 > > drwxr-xr-x 2 root root 4096 Jan 1 1970 . > > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > > -rwxr-xr-x 1 root root 4 Oct 28 03:44 aaa > > -rwxr-xr-x 1 root root 0 Oct 28 01:09 bbb > > ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:1001:1 /mnt /mnt-1001/ > > ubuntu@f2-vm:/$ ls -al /mnt-1001/ > > total 12 > > drwxr-xr-x 2 u1001 u1001 4096 Jan 1 1970 . > > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > > -rwxr-xr-x 1 u1001 u1001 4 Oct 28 03:44 aaa > > -rwxr-xr-x 1 u1001 u1001 0 Oct 28 01:09 bbb > > ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:5000:1 /mnt /mnt-5000/ > > ubuntu@f2-vm:/$ ls -al /mnt-5000/ > > total 12 > > drwxr-xr-x 2 5000 5000 4096 Jan 1 1970 . > > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > > -rwxr-xr-x 1 5000 5000 4 Oct 28 03:44 aaa > > -rwxr-xr-x 1 5000 5000 0 Oct 28 01:09 bbb > > > > 4. Create an idmapped rootfs mount for a container > > > > root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/ > > total 68 > > drwxr-xr-x 17 20000 20000 4096 Sep 24 07:48 . > > drwxrwx--- 3 20000 20000 4096 Oct 16 19:26 .. > > lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 bin -> usr/bin > > drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 boot > > drwxr-xr-x 3 20000 20000 4096 Oct 16 19:26 dev > > drwxr-xr-x 61 20000 20000 4096 Oct 16 19:26 etc > > drwxr-xr-x 3 20000 20000 4096 Sep 24 07:45 home > > lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 lib -> usr/lib > > lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib32 -> usr/lib32 > > lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib64 -> usr/lib64 > > lrwxrwxrwx 1 20000 20000 10 Sep 24 07:43 libx32 -> usr/libx32 > > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 media > > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 mnt > > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 opt > > drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 proc > > drwx------ 2 20000 20000 4096 Sep 24 07:43 root > > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:45 run > > lrwxrwxrwx 1 20000 20000 8 Sep 24 07:43 sbin -> usr/sbin > > drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 srv > > drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 sys > > drwxrwxrwt 2 20000 20000 4096 Sep 24 07:44 tmp > > drwxr-xr-x 13 20000 20000 4096 Sep 24 07:43 usr > > drwxr-xr-x 12 20000 20000 4096 Sep 24 07:44 var > > root@f2-vm:~# /mount-idmapped --map-mount b:20000:10000:100000 /var/lib/lxc/f2/rootfs/ /mnt > > root@f2-vm:~# ls -al /mnt > > total 68 > > drwxr-xr-x 17 10000 10000 4096 Sep 24 07:48 . > > drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. > > lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 bin -> usr/bin > > drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 boot > > drwxr-xr-x 3 10000 10000 4096 Oct 16 19:26 dev > > drwxr-xr-x 61 10000 10000 4096 Oct 16 19:26 etc > > drwxr-xr-x 3 10000 10000 4096 Sep 24 07:45 home > > lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 lib -> usr/lib > > lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib32 -> usr/lib32 > > lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib64 -> usr/lib64 > > lrwxrwxrwx 1 10000 10000 10 Sep 24 07:43 libx32 -> usr/libx32 > > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 media > > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 mnt > > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 opt > > drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 proc > > drwx------ 2 10000 10000 4096 Sep 24 07:43 root > > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:45 run > > lrwxrwxrwx 1 10000 10000 8 Sep 24 07:43 sbin -> usr/sbin > > drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 srv > > drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 sys > > drwxrwxrwt 2 10000 10000 4096 Sep 24 07:44 tmp > > drwxr-xr-x 13 10000 10000 4096 Sep 24 07:43 usr > > drwxr-xr-x 12 10000 10000 4096 Sep 24 07:44 var > > root@f2-vm:~# lxc-start f2 # uses /mnt as rootfs > > root@f2-vm:~# lxc-attach f2 -- cat /proc/1/uid_map > > 0 10000 10000 > > root@f2-vm:~# lxc-attach f2 -- cat /proc/1/gid_map > > 0 10000 10000 > > root@f2-vm:~# lxc-attach f2 -- ls -al / > > total 52 > > drwxr-xr-x 17 root root 4096 Sep 24 07:48 . > > drwxr-xr-x 17 root root 4096 Sep 24 07:48 .. > > lrwxrwxrwx 1 root root 7 Sep 24 07:43 bin -> usr/bin > > drwxr-xr-x 2 root root 4096 Apr 15 2020 boot > > drwxr-xr-x 5 root root 500 Oct 28 23:39 dev > > drwxr-xr-x 61 root root 4096 Oct 28 23:39 etc > > drwxr-xr-x 3 root root 4096 Sep 24 07:45 home > > lrwxrwxrwx 1 root root 7 Sep 24 07:43 lib -> usr/lib > > lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib32 -> usr/lib32 > > lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib64 -> usr/lib64 > > lrwxrwxrwx 1 root root 10 Sep 24 07:43 libx32 -> usr/libx32 > > drwxr-xr-x 2 root root 4096 Sep 24 07:43 media > > drwxr-xr-x 2 root root 4096 Sep 24 07:43 mnt > > drwxr-xr-x 2 root root 4096 Sep 24 07:43 opt > > dr-xr-xr-x 232 nobody nogroup 0 Oct 28 23:39 proc > > drwx------ 2 root root 4096 Oct 28 23:41 root > > drwxr-xr-x 12 root root 360 Oct 28 23:39 run > > lrwxrwxrwx 1 root root 8 Sep 24 07:43 sbin -> usr/sbin > > drwxr-xr-x 2 root root 4096 Sep 24 07:43 srv > > dr-xr-xr-x 13 nobody nogroup 0 Oct 28 23:39 sys > > drwxrwxrwt 11 root root 4096 Oct 28 23:40 tmp > > drwxr-xr-x 13 root root 4096 Sep 24 07:43 usr > > drwxr-xr-x 12 root root 4096 Sep 24 07:44 var > > root@f2-vm:~# lxc-attach f2 -- ls -al /my-file > > -rw-r--r-- 1 root root 0 Oct 28 23:43 /my-file > > root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/my-file > > -rw-r--r-- 1 20000 20000 0 Oct 28 23:43 /var/lib/lxc/f2/rootfs/my-file > > > > I'd like to say thanks to: > > Al for pointing me into the direction to avoid inode alias issues during > > lookup. David for various discussions around this. Christoph for proving > > a first proper review and for being involved in the original idea. Tycho > > for helping with this series and on future patches to convert > > filesystems. Alban Crequy and the Kinvolk located just a few streets > > away from me in Berlin for providing use-case discussions and writing > > patches for containerd! Stéphane for his invaluable input on many things > > and level head and enabling me to work on this. Amir for explaining and > > discussing aspects of overlayfs with me. I'd like to especially thank > > Seth Forshee because he provided a lot of good analysis, suggestions, > > and participated in short-notice discussions in both chat and video for > > some nitty-gritty technical details. > > > > This series can be found and pulled from the three usual locations: > > https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git/log/?h=idmapped_mounts > > https://github.com/brauner/linux/tree/idmapped_mounts > > https://gitlab.com/brauner/linux/-/commits/idmapped_mounts > > > > Thanks! > > Christian > > > > Christian Brauner (37): > > namespace: take lock_mount_hash() directly when changing flags > > mount: make {lock,unlock}_mount_hash() static > > namespace: only take read lock in do_reconfigure_mnt() > > fs: add mount_setattr() > > tests: add mount_setattr() selftests > > fs: add id translation helpers > > mount: attach mappings to mounts > > capability: handle idmapped mounts > > namei: add idmapped mount aware permission helpers > > inode: add idmapped mount aware init and permission helpers > > attr: handle idmapped mounts > > acl: handle idmapped mounts > > commoncap: handle idmapped mounts > > stat: handle idmapped mounts > > namei: handle idmapped mounts in may_*() helpers > > namei: introduce struct renamedata > > namei: prepare for idmapped mounts > > open: handle idmapped mounts in do_truncate() > > open: handle idmapped mounts > > af_unix: handle idmapped mounts > > utimes: handle idmapped mounts > > fcntl: handle idmapped mounts > > notify: handle idmapped mounts > > init: handle idmapped mounts > > ioctl: handle idmapped mounts > > would_dump: handle idmapped mounts > > exec: handle idmapped mounts > > fs: add helpers for idmap mounts > > apparmor: handle idmapped mounts > > audit: handle idmapped mounts > > ima: handle idmapped mounts > > fat: handle idmapped mounts > > ext4: support idmapped mounts > > ecryptfs: do not mount on top of idmapped mounts > > overlayfs: do not mount on top of idmapped mounts > > fs: introduce MOUNT_ATTR_IDMAP > > tests: add vfs/idmapped mounts test suite > > > > Tycho Andersen (2): > > xattr: handle idmapped mounts > > selftests: add idmapped mounts xattr selftest > > > > Documentation/filesystems/locking.rst | 6 +- > > Documentation/filesystems/porting.rst | 2 + > > Documentation/filesystems/vfs.rst | 17 +- > > arch/alpha/kernel/syscalls/syscall.tbl | 1 + > > arch/arm/tools/syscall.tbl | 1 + > > arch/arm64/include/asm/unistd32.h | 2 + > > arch/ia64/kernel/syscalls/syscall.tbl | 1 + > > arch/m68k/kernel/syscalls/syscall.tbl | 1 + > > arch/microblaze/kernel/syscalls/syscall.tbl | 1 + > > arch/mips/kernel/syscalls/syscall_n32.tbl | 1 + > > arch/mips/kernel/syscalls/syscall_n64.tbl | 1 + > > arch/mips/kernel/syscalls/syscall_o32.tbl | 1 + > > arch/parisc/kernel/syscalls/syscall.tbl | 1 + > > arch/powerpc/kernel/syscalls/syscall.tbl | 1 + > > arch/powerpc/platforms/cell/spufs/inode.c | 5 +- > > arch/s390/kernel/syscalls/syscall.tbl | 1 + > > arch/sh/kernel/syscalls/syscall.tbl | 1 + > > arch/sparc/kernel/syscalls/syscall.tbl | 1 + > > arch/x86/entry/syscalls/syscall_32.tbl | 1 + > > arch/x86/entry/syscalls/syscall_64.tbl | 1 + > > arch/xtensa/kernel/syscalls/syscall.tbl | 1 + > > drivers/android/binderfs.c | 3 +- > > drivers/base/devtmpfs.c | 12 +- > > fs/9p/acl.c | 7 +- > > fs/9p/v9fs.h | 3 +- > > fs/9p/v9fs_vfs.h | 2 +- > > fs/9p/vfs_inode.c | 32 +- > > fs/9p/vfs_inode_dotl.c | 34 +- > > fs/9p/xattr.c | 1 + > > fs/adfs/adfs.h | 3 +- > > fs/adfs/inode.c | 5 +- > > fs/affs/affs.h | 10 +- > > fs/affs/inode.c | 7 +- > > fs/affs/namei.c | 15 +- > > fs/afs/dir.c | 34 +- > > fs/afs/inode.c | 5 +- > > fs/afs/internal.h | 4 +- > > fs/afs/security.c | 2 +- > > fs/afs/xattr.c | 2 + > > fs/attr.c | 78 +- > > fs/autofs/root.c | 13 +- > > fs/bad_inode.c | 31 +- > > fs/bfs/dir.c | 12 +- > > fs/btrfs/acl.c | 5 +- > > fs/btrfs/ctree.h | 3 +- > > fs/btrfs/inode.c | 41 +- > > fs/btrfs/ioctl.c | 25 +- > > fs/btrfs/tests/btrfs-tests.c | 2 +- > > fs/btrfs/xattr.c | 2 + > > fs/cachefiles/interface.c | 4 +- > > fs/cachefiles/namei.c | 19 +- > > fs/cachefiles/xattr.c | 16 +- > > fs/ceph/acl.c | 5 +- > > fs/ceph/dir.c | 23 +- > > fs/ceph/inode.c | 13 +- > > fs/ceph/super.h | 8 +- > > fs/ceph/xattr.c | 1 + > > fs/cifs/cifsfs.c | 4 +- > > fs/cifs/cifsfs.h | 18 +- > > fs/cifs/dir.c | 8 +- > > fs/cifs/inode.c | 22 +- > > fs/cifs/link.c | 3 +- > > fs/cifs/xattr.c | 1 + > > fs/coda/coda_linux.h | 4 +- > > fs/coda/dir.c | 18 +- > > fs/coda/inode.c | 5 +- > > fs/coda/pioctl.c | 6 +- > > fs/configfs/configfs_internal.h | 7 +- > > fs/configfs/dir.c | 3 +- > > fs/configfs/inode.c | 5 +- > > fs/configfs/symlink.c | 5 +- > > fs/coredump.c | 12 +- > > fs/crypto/policy.c | 2 +- > > fs/debugfs/inode.c | 9 +- > > fs/ecryptfs/crypto.c | 4 +- > > fs/ecryptfs/inode.c | 74 +- > > fs/ecryptfs/main.c | 6 + > > fs/ecryptfs/mmap.c | 4 +- > > fs/efivarfs/file.c | 2 +- > > fs/efivarfs/inode.c | 4 +- > > fs/erofs/inode.c | 2 +- > > fs/exec.c | 12 +- > > fs/exfat/exfat_fs.h | 3 +- > > fs/exfat/file.c | 9 +- > > fs/exfat/namei.c | 13 +- > > fs/ext2/acl.c | 5 +- > > fs/ext2/acl.h | 3 +- > > fs/ext2/ext2.h | 2 +- > > fs/ext2/ialloc.c | 2 +- > > fs/ext2/inode.c | 11 +- > > fs/ext2/ioctl.c | 6 +- > > fs/ext2/namei.c | 22 +- > > fs/ext2/xattr_security.c | 1 + > > fs/ext2/xattr_trusted.c | 1 + > > fs/ext2/xattr_user.c | 1 + > > fs/ext4/Kconfig | 9 + > > fs/ext4/acl.c | 5 +- > > fs/ext4/acl.h | 3 +- > > fs/ext4/ext4.h | 15 +- > > fs/ext4/ialloc.c | 7 +- > > fs/ext4/inode.c | 14 +- > > fs/ext4/ioctl.c | 18 +- > > fs/ext4/namei.c | 52 +- > > fs/ext4/super.c | 6 +- > > fs/ext4/xattr_hurd.c | 1 + > > fs/ext4/xattr_security.c | 1 + > > fs/ext4/xattr_trusted.c | 1 + > > fs/ext4/xattr_user.c | 1 + > > fs/f2fs/acl.c | 5 +- > > fs/f2fs/acl.h | 3 +- > > fs/f2fs/f2fs.h | 3 +- > > fs/f2fs/file.c | 23 +- > > fs/f2fs/namei.c | 26 +- > > fs/f2fs/xattr.c | 4 +- > > fs/fat/fat.h | 3 +- > > fs/fat/file.c | 20 +- > > fs/fat/namei_msdos.c | 15 +- > > fs/fat/namei_vfat.c | 15 +- > > fs/fcntl.c | 3 +- > > fs/fuse/acl.c | 3 +- > > fs/fuse/dir.c | 41 +- > > fs/fuse/fuse_i.h | 4 +- > > fs/fuse/xattr.c | 2 + > > fs/gfs2/acl.c | 5 +- > > fs/gfs2/acl.h | 3 +- > > fs/gfs2/file.c | 4 +- > > fs/gfs2/inode.c | 54 +- > > fs/gfs2/inode.h | 2 +- > > fs/gfs2/xattr.c | 1 + > > fs/hfs/attr.c | 1 + > > fs/hfs/dir.c | 13 +- > > fs/hfs/hfs_fs.h | 2 +- > > fs/hfs/inode.c | 7 +- > > fs/hfsplus/dir.c | 25 +- > > fs/hfsplus/inode.c | 11 +- > > fs/hfsplus/ioctl.c | 2 +- > > fs/hfsplus/xattr.c | 1 + > > fs/hfsplus/xattr_security.c | 1 + > > fs/hfsplus/xattr_trusted.c | 1 + > > fs/hfsplus/xattr_user.c | 1 + > > fs/hostfs/hostfs_kern.c | 31 +- > > fs/hpfs/hpfs_fn.h | 2 +- > > fs/hpfs/inode.c | 7 +- > > fs/hpfs/namei.c | 20 +- > > fs/hugetlbfs/inode.c | 31 +- > > fs/init.c | 21 +- > > fs/inode.c | 38 +- > > fs/internal.h | 9 + > > fs/jffs2/acl.c | 5 +- > > fs/jffs2/acl.h | 3 +- > > fs/jffs2/dir.c | 32 +- > > fs/jffs2/fs.c | 7 +- > > fs/jffs2/os-linux.h | 2 +- > > fs/jffs2/security.c | 1 + > > fs/jffs2/xattr_trusted.c | 1 + > > fs/jffs2/xattr_user.c | 1 + > > fs/jfs/acl.c | 5 +- > > fs/jfs/file.c | 9 +- > > fs/jfs/ioctl.c | 2 +- > > fs/jfs/jfs_acl.h | 3 +- > > fs/jfs/jfs_inode.c | 2 +- > > fs/jfs/jfs_inode.h | 2 +- > > fs/jfs/namei.c | 21 +- > > fs/jfs/xattr.c | 2 + > > fs/kernfs/dir.c | 7 +- > > fs/kernfs/inode.c | 15 +- > > fs/kernfs/kernfs-internal.h | 5 +- > > fs/libfs.c | 20 +- > > fs/minix/bitmap.c | 2 +- > > fs/minix/file.c | 7 +- > > fs/minix/inode.c | 2 +- > > fs/minix/namei.c | 25 +- > > fs/mount.h | 10 - > > fs/namei.c | 317 +- > > fs/namespace.c | 473 ++- > > fs/nfs/dir.c | 23 +- > > fs/nfs/inode.c | 5 +- > > fs/nfs/internal.h | 10 +- > > fs/nfs/namespace.c | 7 +- > > fs/nfs/nfs3_fs.h | 3 +- > > fs/nfs/nfs3acl.c | 3 +- > > fs/nfs/nfs4proc.c | 3 + > > fs/nfsd/nfs2acl.c | 4 +- > > fs/nfsd/nfs3acl.c | 4 +- > > fs/nfsd/nfs4acl.c | 4 +- > > fs/nfsd/nfs4recover.c | 6 +- > > fs/nfsd/nfsfh.c | 2 +- > > fs/nfsd/nfsproc.c | 2 +- > > fs/nfsd/vfs.c | 47 +- > > fs/nilfs2/inode.c | 13 +- > > fs/nilfs2/ioctl.c | 2 +- > > fs/nilfs2/namei.c | 20 +- > > fs/nilfs2/nilfs.h | 4 +- > > fs/notify/fanotify/fanotify_user.c | 2 +- > > fs/notify/inotify/inotify_user.c | 3 +- > > fs/ntfs/inode.c | 2 +- > > fs/ocfs2/acl.c | 5 +- > > fs/ocfs2/acl.h | 3 +- > > fs/ocfs2/dlmfs/dlmfs.c | 17 +- > > fs/ocfs2/file.c | 13 +- > > fs/ocfs2/file.h | 5 +- > > fs/ocfs2/ioctl.c | 2 +- > > fs/ocfs2/namei.c | 21 +- > > fs/ocfs2/refcounttree.c | 4 +- > > fs/ocfs2/xattr.c | 3 + > > fs/omfs/dir.c | 13 +- > > fs/omfs/file.c | 7 +- > > fs/omfs/inode.c | 2 +- > > fs/open.c | 52 +- > > fs/orangefs/acl.c | 5 +- > > fs/orangefs/inode.c | 15 +- > > fs/orangefs/namei.c | 12 +- > > fs/orangefs/orangefs-kernel.h | 7 +- > > fs/orangefs/xattr.c | 1 + > > fs/overlayfs/copy_up.c | 20 +- > > fs/overlayfs/dir.c | 31 +- > > fs/overlayfs/file.c | 6 +- > > fs/overlayfs/inode.c | 21 +- > > fs/overlayfs/overlayfs.h | 40 +- > > fs/overlayfs/super.c | 27 +- > > fs/overlayfs/util.c | 4 +- > > fs/posix_acl.c | 78 +- > > fs/proc/base.c | 24 +- > > fs/proc/fd.c | 4 +- > > fs/proc/fd.h | 3 +- > > fs/proc/generic.c | 9 +- > > fs/proc/internal.h | 2 +- > > fs/proc/proc_net.c | 2 +- > > fs/proc/proc_sysctl.c | 12 +- > > fs/proc/root.c | 2 +- > > fs/proc_namespace.c | 1 + > > fs/ramfs/file-nommu.c | 9 +- > > fs/ramfs/inode.c | 18 +- > > fs/reiserfs/acl.h | 3 +- > > fs/reiserfs/inode.c | 7 +- > > fs/reiserfs/ioctl.c | 4 +- > > fs/reiserfs/namei.c | 21 +- > > fs/reiserfs/reiserfs.h | 3 +- > > fs/reiserfs/xattr.c | 12 +- > > fs/reiserfs/xattr.h | 2 +- > > fs/reiserfs/xattr_acl.c | 7 +- > > fs/reiserfs/xattr_security.c | 3 +- > > fs/reiserfs/xattr_trusted.c | 3 +- > > fs/reiserfs/xattr_user.c | 3 +- > > fs/remap_range.c | 7 +- > > fs/stat.c | 10 +- > > fs/sysv/file.c | 7 +- > > fs/sysv/ialloc.c | 2 +- > > fs/sysv/itree.c | 2 +- > > fs/sysv/namei.c | 21 +- > > fs/tracefs/inode.c | 4 +- > > fs/ubifs/dir.c | 29 +- > > fs/ubifs/file.c | 5 +- > > fs/ubifs/ioctl.c | 2 +- > > fs/ubifs/ubifs.h | 3 +- > > fs/ubifs/xattr.c | 1 + > > fs/udf/file.c | 9 +- > > fs/udf/ialloc.c | 2 +- > > fs/udf/namei.c | 24 +- > > fs/udf/symlink.c | 2 +- > > fs/ufs/ialloc.c | 2 +- > > fs/ufs/inode.c | 7 +- > > fs/ufs/namei.c | 19 +- > > fs/ufs/ufs.h | 3 +- > > fs/utimes.c | 4 +- > > fs/vboxsf/dir.c | 12 +- > > fs/vboxsf/utils.c | 5 +- > > fs/vboxsf/vfsmod.h | 3 +- > > fs/verity/enable.c | 2 +- > > fs/xattr.c | 136 +- > > fs/xfs/xfs_acl.c | 5 +- > > fs/xfs/xfs_acl.h | 3 +- > > fs/xfs/xfs_ioctl.c | 4 +- > > fs/xfs/xfs_iops.c | 55 +- > > fs/xfs/xfs_xattr.c | 3 +- > > fs/zonefs/super.c | 9 +- > > include/linux/audit.h | 10 +- > > include/linux/capability.h | 14 +- > > include/linux/fs.h | 145 +- > > include/linux/ima.h | 15 +- > > include/linux/lsm_hook_defs.h | 15 +- > > include/linux/lsm_hooks.h | 1 + > > include/linux/mount.h | 14 +- > > include/linux/nfs_fs.h | 4 +- > > include/linux/posix_acl.h | 15 +- > > include/linux/posix_acl_xattr.h | 12 +- > > include/linux/security.h | 44 +- > > include/linux/syscalls.h | 3 + > > include/linux/xattr.h | 30 +- > > include/uapi/asm-generic/unistd.h | 4 +- > > include/uapi/linux/mount.h | 25 + > > ipc/mqueue.c | 16 +- > > kernel/auditsc.c | 29 +- > > kernel/bpf/inode.c | 13 +- > > kernel/capability.c | 14 +- > > kernel/cgroup/cgroup.c | 2 +- > > kernel/sys.c | 2 +- > > mm/madvise.c | 4 +- > > mm/memcontrol.c | 2 +- > > mm/mincore.c | 4 +- > > mm/shmem.c | 45 +- > > net/socket.c | 6 +- > > net/unix/af_unix.c | 4 +- > > security/apparmor/apparmorfs.c | 3 +- > > security/apparmor/domain.c | 13 +- > > security/apparmor/file.c | 5 +- > > security/apparmor/lsm.c | 12 +- > > security/commoncap.c | 46 +- > > security/integrity/evm/evm_crypto.c | 11 +- > > security/integrity/evm/evm_main.c | 4 +- > > security/integrity/evm/evm_secfs.c | 2 +- > > security/integrity/ima/ima.h | 19 +- > > security/integrity/ima/ima_api.c | 10 +- > > security/integrity/ima/ima_appraise.c | 22 +- > > security/integrity/ima/ima_asymmetric_keys.c | 2 +- > > security/integrity/ima/ima_main.c | 28 +- > > security/integrity/ima/ima_policy.c | 17 +- > > security/integrity/ima/ima_queue_keys.c | 2 +- > > security/security.c | 25 +- > > security/selinux/hooks.c | 22 +- > > security/smack/smack_lsm.c | 18 +- > > tools/include/uapi/asm-generic/unistd.h | 4 +- > > tools/testing/selftests/Makefile | 1 + > > .../testing/selftests/idmap_mounts/.gitignore | 2 + > > tools/testing/selftests/idmap_mounts/Makefile | 12 + > > tools/testing/selftests/idmap_mounts/config | 1 + > > tools/testing/selftests/idmap_mounts/core.c | 3476 +++++++++++++++++ > > .../testing/selftests/idmap_mounts/internal.h | 127 + > > tools/testing/selftests/idmap_mounts/utils.c | 136 + > > tools/testing/selftests/idmap_mounts/utils.h | 17 + > > tools/testing/selftests/idmap_mounts/xattr.c | 172 + > > .../selftests/mount_setattr/.gitignore | 1 + > > .../testing/selftests/mount_setattr/Makefile | 7 + > > tools/testing/selftests/mount_setattr/config | 1 + > > .../mount_setattr/mount_setattr_test.c | 889 +++++ > > 335 files changed, 7594 insertions(+), 1570 deletions(-) > > create mode 100644 tools/testing/selftests/idmap_mounts/.gitignore > > create mode 100644 tools/testing/selftests/idmap_mounts/Makefile > > create mode 100644 tools/testing/selftests/idmap_mounts/config > > create mode 100644 tools/testing/selftests/idmap_mounts/core.c > > create mode 100644 tools/testing/selftests/idmap_mounts/internal.h > > create mode 100644 tools/testing/selftests/idmap_mounts/utils.c > > create mode 100644 tools/testing/selftests/idmap_mounts/utils.h > > create mode 100644 tools/testing/selftests/idmap_mounts/xattr.c > > create mode 100644 tools/testing/selftests/mount_setattr/.gitignore > > create mode 100644 tools/testing/selftests/mount_setattr/Makefile > > create mode 100644 tools/testing/selftests/mount_setattr/config > > create mode 100644 tools/testing/selftests/mount_setattr/mount_setattr_test.c > > > > > > base-commit: 3cea11cd5e3b00d91caf0b4730194039b45c5891 > > -- > > 2.29.2 > >
On Fri, Nov 20, 2020 at 10:10:44AM +0100, Christian Brauner wrote: > Maybe you didn't see this or you're referring to xfstests but this > series contains a >=4000 lines long test-suite that validates all core > features with and without idmapped mounts. It's the last patch in this > version of the series and it's located in: > tools/testing/selftests/idmap_mounts. > > Everytime a filesystem is added this test-suite will be updated. We > would perfer if this test would be shipped with the kernel itself and > not in a separate test-suite such as xfstests. But we're happy to add > patches for the latter at some point too. selftests is a complete pain to use, partialy because it is not integrated with the framework we file system developers use (xfstests) and partially because having the test suite in the kernel tree really breaks a lot of the typical use cases. So I think we'll need to wire this up in the proper place instead.
On Fri, Nov 20, 2020 at 09:12:47AM +0000, Christoph Hellwig wrote: > On Fri, Nov 20, 2020 at 10:10:44AM +0100, Christian Brauner wrote: > > Maybe you didn't see this or you're referring to xfstests but this > > series contains a >=4000 lines long test-suite that validates all core > > features with and without idmapped mounts. It's the last patch in this > > version of the series and it's located in: > > tools/testing/selftests/idmap_mounts. > > > > Everytime a filesystem is added this test-suite will be updated. We > > would perfer if this test would be shipped with the kernel itself and > > not in a separate test-suite such as xfstests. But we're happy to add > > patches for the latter at some point too. > > selftests is a complete pain to use, partialy because it is not > integrated with the framework we file system developers use (xfstests) > and partially because having the test suite in the kernel tree really > breaks a lot of the typical use cases. So I think we'll need to wire > this up in the proper place instead. Ok, I think I can basically port the test-suite at the end of this patch series so that it can be carried in xfstests/src/idmapped_mounts.c I'll start doing that now. It would make it a bit easier if we could carry it as a single file for now. Christian
Hey everyone, This is v2. It is reworked according to the reviews coming from Christoph and others to adapt all relevant helpers and inode_operations methods to account for idmapped mounts instead of introducing new helpers and methods specific to idmapped mounts like we did before. We've also moved the overlayfs conversion to handle idmapped mounts into a separate patchset that will be sent out separately after the core changes. The converted filesytems in this series include fat and ext4. The config option to disable idmapped mounts has been moved from a a vfs config ption to a per-filesystem option. They default to off. Having a config option allows us to gain some confidence in the patchset over multiple kernel releases. There are two noteable things about this version. First, that it comes with a really large test-suite to test current vfs behavior and idmapped mounts behavior. We intend this test-suite to grow over time and at some point cover most basic core vfs functionality that isn't covered in xfstests and have it be part of the selftests. Second, while while working on adapting this patchset to the requested changes, the runC and containerd crowd was nice enough to adapt containerd to this patchset to make use of idmapped mounts in one of the most widely used container runtimes: https://github.com/containerd/containerd/pull/4734 With this patchset we make it possible to attach idmappings to bind mounts. This handles several common use-cases. Here are just a few: - Shifting of a container rootfs or base image without having to mangle every file (runc, Docker, containerd, k8s, LXD, systemd ...) - Sharing of data between host or privileged containers with underprivileged containers (runc, Docker, containerd, k8s, LXD, ...) - Shifting of subset of ownership-less filesystems (vfat) for use by multiple users, effectively allowing for DAC on such devices (systemd, Android, ...) - Data sharing between multiple user namespaces with incompatible maps (LXD, k8s, ...) Making it possible to share directories and mounts between users with different uids and gids is itself quite an important use-case in distributed systems environments. It's of course especially useful in general for portable usb sticks, sharing data between multiple users in general, and sharing home directories between multiple users. The last example is now elegantly expressed in systemd's homed concept for portable home directories. As mentioned above, idmapped mounts also allow data from the host to be shared with unprivileged containers, between privileged and unprivileged containers simultaneously and in addition also between unprivileged containers with different idmappings whenever they are used to isolate one container completely from another container. As can be seen from answers to earlier threads of this patchset and from the list of potential users interest in this patchset is fairly widespread. We have implemented and proposed multiple solutions to this before. This included the introduction of fsid mappings, a tiny filesystem that is currently carried in Ubuntu that has shown it's limitations, and an approach to call override creds in the vfs. None of these solutions have covered all of the above use-cases. Some of them have been fairly hacky too by e.g. violating how things should be passed down to the individual filesystems. The solution proposed here has it's origins in multiple discussions during Linux Plumbers 2017 during and after the end of the containers microconference. To the best of my knowledge this involved Aleksa, Stéphane, Eric, David, James, and myself. The original idea or a variant thereof has been discussed, again to the best of my knowledge, after a Linux conference in St. Petersburg in Russia in 2017 between Christoph, Tycho, and myself. We've taken the time to implement a working version of this solution over the last weeks to the best of my abilities. Tycho has signed up for this sligthly crazy endeavour as well and he has helped with the conversion of the xattr codepaths and will be involved with others in converting additional filesystems. This series makes idmappings a property of struct vfsmount instead of tying it to a process being inside of a user namespace which has been the case for all other proposed approaches. It also allows to pass down the user namespace into the filesystms which is a clean way instead of violating calling conventions by strapping the user namespace information that is a property of the mount to the caller's credentials or similar hacks. With this idmappings become a property of bind-mounts, i.e. each bind-mount can have a separate idmapping. Such idmapped mounts can even be created inside of the initial user namespace. The vfsmount struct gains a new struct user_namespace member. The idmapping of the user namespace becomes the idmapping of the mount. A caller that is privileged with respect to the user namespace of the superblock of the underlying filesystem can create an idmapped bind-mount. In the future, we can enable unprivileged use-cases by checking whether the caller is privileged wrt to the user namespace an already idmapped mount has been marked with, allowing them to change the idmapping. For now, keep things simple until we feel sure enough. Note, that with syscall interception it is already possible to intercept idmapped mount requests from unprivileged containers and handle them in a sufficiently privileged container manager. Support for this is already available in LXD and will be available in runC were syscall interception is currently becoming part of the runtime spec (see https://github.com/opencontainers/runtime-spec/pull/1074). The user namespace the mount will be marked with can be specified by passing a file descriptor refering to the user namespace as an argument to the new mount_setattr() syscall together with the new MOUNT_ATTR_IDMAP flag. By default vfsmounts are marked with the initial user namespace and no behavioral or performance changes should be observed. All mapping operations are nops for the initial user namespace. When a file/inode is accessed through an idmapped mount the i_uid and i_gid of the inode will be remapped according to the user namespace the mount has been marked with. In order to support idmapped mounts, filesystems need to be changed and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The initial version contains fat and ext4 including a list of examples. But patches for other filesystems are actively worked on but will be sent out separately. We are here to see this through and there are multiple people involved in converting filesystems. So filesystem developers are not left alone with this. I have written a simple tool available at https://github.com/brauner/mount-idmapped that allows to create idmapped mounts so people can play with this patch series. Here are a few illustrations: 1. Create a simple idmapped mount of another user's home directory u1001@f2-vm:/$ sudo ./mount-idmapped --map-mount b:1000:1001:1 /home/ubuntu/ /mnt u1001@f2-vm:/$ ls -al /home/ubuntu/ total 28 drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 . drwxr-xr-x 4 root root 4096 Oct 28 04:00 .. -rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ ls -al /mnt/ total 28 drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 . drwxr-xr-x 29 root root 4096 Oct 28 22:01 .. -rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile -rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ touch /mnt/my-file u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file u1001@f2-vm:/$ ls -al /mnt/my-file -rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file u1001@f2-vm:/$ ls -al /home/ubuntu/my-file -rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file u1001@f2-vm:/$ getfacl /mnt/my-file getfacl: Removing leading '/' from absolute path names # file: mnt/my-file # owner: u1001 # group: u1001 user::rw- user:u1001:rwx group::rw- mask::rwx other::r-- u1001@f2-vm:/$ getfacl /home/ubuntu/my-file getfacl: Removing leading '/' from absolute path names # file: home/ubuntu/my-file # owner: ubuntu # group: ubuntu user::rw- user:ubuntu:rwx group::rw- mask::rwx other::r-- 2. Create mapping of the whole ext4 rootfs without a mapping for uid and gid 0 ubuntu@f2-vm:~$ sudo /mount-idmapped --map-mount b:1:1:65536 / /mnt/ ubuntu@f2-vm:~$ findmnt | grep mnt └─/mnt /dev/sda2 ext4 rw,relatime └─/mnt/mnt /dev/sda2 ext4 rw,relatime ubuntu@f2-vm:~$ sudo mkdir /AS-ROOT-CAN-CREATE ubuntu@f2-vm:~$ sudo mkdir /mnt/AS-ROOT-CANT-CREATE mkdir: cannot create directory ‘/mnt/AS-ROOT-CANT-CREATE’: Value too large for defined data type ubuntu@f2-vm:~$ mkdir /mnt/home/ubuntu/AS-USER-1000-CAN-CREATE 3. Create a vfat usb mount and expose to user 1001 and 5000 ubuntu@f2-vm:/$ sudo mount /dev/sdb /mnt ubuntu@f2-vm:/$ findmnt | grep mnt └─/mnt /dev/sdb vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro ubuntu@f2-vm:/$ ls -al /mnt total 12 drwxr-xr-x 2 root root 4096 Jan 1 1970 . drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. -rwxr-xr-x 1 root root 4 Oct 28 03:44 aaa -rwxr-xr-x 1 root root 0 Oct 28 01:09 bbb ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:1001:1 /mnt /mnt-1001/ ubuntu@f2-vm:/$ ls -al /mnt-1001/ total 12 drwxr-xr-x 2 u1001 u1001 4096 Jan 1 1970 . drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. -rwxr-xr-x 1 u1001 u1001 4 Oct 28 03:44 aaa -rwxr-xr-x 1 u1001 u1001 0 Oct 28 01:09 bbb ubuntu@f2-vm:/$ sudo /mount-idmapped --map-mount b:0:5000:1 /mnt /mnt-5000/ ubuntu@f2-vm:/$ ls -al /mnt-5000/ total 12 drwxr-xr-x 2 5000 5000 4096 Jan 1 1970 . drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. -rwxr-xr-x 1 5000 5000 4 Oct 28 03:44 aaa -rwxr-xr-x 1 5000 5000 0 Oct 28 01:09 bbb 4. Create an idmapped rootfs mount for a container root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/ total 68 drwxr-xr-x 17 20000 20000 4096 Sep 24 07:48 . drwxrwx--- 3 20000 20000 4096 Oct 16 19:26 .. lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 bin -> usr/bin drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 boot drwxr-xr-x 3 20000 20000 4096 Oct 16 19:26 dev drwxr-xr-x 61 20000 20000 4096 Oct 16 19:26 etc drwxr-xr-x 3 20000 20000 4096 Sep 24 07:45 home lrwxrwxrwx 1 20000 20000 7 Sep 24 07:43 lib -> usr/lib lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib32 -> usr/lib32 lrwxrwxrwx 1 20000 20000 9 Sep 24 07:43 lib64 -> usr/lib64 lrwxrwxrwx 1 20000 20000 10 Sep 24 07:43 libx32 -> usr/libx32 drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 media drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 mnt drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 opt drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 proc drwx------ 2 20000 20000 4096 Sep 24 07:43 root drwxr-xr-x 2 20000 20000 4096 Sep 24 07:45 run lrwxrwxrwx 1 20000 20000 8 Sep 24 07:43 sbin -> usr/sbin drwxr-xr-x 2 20000 20000 4096 Sep 24 07:43 srv drwxr-xr-x 2 20000 20000 4096 Apr 15 2020 sys drwxrwxrwt 2 20000 20000 4096 Sep 24 07:44 tmp drwxr-xr-x 13 20000 20000 4096 Sep 24 07:43 usr drwxr-xr-x 12 20000 20000 4096 Sep 24 07:44 var root@f2-vm:~# /mount-idmapped --map-mount b:20000:10000:100000 /var/lib/lxc/f2/rootfs/ /mnt root@f2-vm:~# ls -al /mnt total 68 drwxr-xr-x 17 10000 10000 4096 Sep 24 07:48 . drwxr-xr-x 34 root root 4096 Oct 28 22:24 .. lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 bin -> usr/bin drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 boot drwxr-xr-x 3 10000 10000 4096 Oct 16 19:26 dev drwxr-xr-x 61 10000 10000 4096 Oct 16 19:26 etc drwxr-xr-x 3 10000 10000 4096 Sep 24 07:45 home lrwxrwxrwx 1 10000 10000 7 Sep 24 07:43 lib -> usr/lib lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib32 -> usr/lib32 lrwxrwxrwx 1 10000 10000 9 Sep 24 07:43 lib64 -> usr/lib64 lrwxrwxrwx 1 10000 10000 10 Sep 24 07:43 libx32 -> usr/libx32 drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 media drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 mnt drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 opt drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 proc drwx------ 2 10000 10000 4096 Sep 24 07:43 root drwxr-xr-x 2 10000 10000 4096 Sep 24 07:45 run lrwxrwxrwx 1 10000 10000 8 Sep 24 07:43 sbin -> usr/sbin drwxr-xr-x 2 10000 10000 4096 Sep 24 07:43 srv drwxr-xr-x 2 10000 10000 4096 Apr 15 2020 sys drwxrwxrwt 2 10000 10000 4096 Sep 24 07:44 tmp drwxr-xr-x 13 10000 10000 4096 Sep 24 07:43 usr drwxr-xr-x 12 10000 10000 4096 Sep 24 07:44 var root@f2-vm:~# lxc-start f2 # uses /mnt as rootfs root@f2-vm:~# lxc-attach f2 -- cat /proc/1/uid_map 0 10000 10000 root@f2-vm:~# lxc-attach f2 -- cat /proc/1/gid_map 0 10000 10000 root@f2-vm:~# lxc-attach f2 -- ls -al / total 52 drwxr-xr-x 17 root root 4096 Sep 24 07:48 . drwxr-xr-x 17 root root 4096 Sep 24 07:48 .. lrwxrwxrwx 1 root root 7 Sep 24 07:43 bin -> usr/bin drwxr-xr-x 2 root root 4096 Apr 15 2020 boot drwxr-xr-x 5 root root 500 Oct 28 23:39 dev drwxr-xr-x 61 root root 4096 Oct 28 23:39 etc drwxr-xr-x 3 root root 4096 Sep 24 07:45 home lrwxrwxrwx 1 root root 7 Sep 24 07:43 lib -> usr/lib lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib32 -> usr/lib32 lrwxrwxrwx 1 root root 9 Sep 24 07:43 lib64 -> usr/lib64 lrwxrwxrwx 1 root root 10 Sep 24 07:43 libx32 -> usr/libx32 drwxr-xr-x 2 root root 4096 Sep 24 07:43 media drwxr-xr-x 2 root root 4096 Sep 24 07:43 mnt drwxr-xr-x 2 root root 4096 Sep 24 07:43 opt dr-xr-xr-x 232 nobody nogroup 0 Oct 28 23:39 proc drwx------ 2 root root 4096 Oct 28 23:41 root drwxr-xr-x 12 root root 360 Oct 28 23:39 run lrwxrwxrwx 1 root root 8 Sep 24 07:43 sbin -> usr/sbin drwxr-xr-x 2 root root 4096 Sep 24 07:43 srv dr-xr-xr-x 13 nobody nogroup 0 Oct 28 23:39 sys drwxrwxrwt 11 root root 4096 Oct 28 23:40 tmp drwxr-xr-x 13 root root 4096 Sep 24 07:43 usr drwxr-xr-x 12 root root 4096 Sep 24 07:44 var root@f2-vm:~# lxc-attach f2 -- ls -al /my-file -rw-r--r-- 1 root root 0 Oct 28 23:43 /my-file root@f2-vm:~# ls -al /var/lib/lxc/f2/rootfs/my-file -rw-r--r-- 1 20000 20000 0 Oct 28 23:43 /var/lib/lxc/f2/rootfs/my-file I'd like to say thanks to: Al for pointing me into the direction to avoid inode alias issues during lookup. David for various discussions around this. Christoph for proving a first proper review and for being involved in the original idea. Tycho for helping with this series and on future patches to convert filesystems. Alban Crequy and the Kinvolk located just a few streets away from me in Berlin for providing use-case discussions and writing patches for containerd! Stéphane for his invaluable input on many things and level head and enabling me to work on this. Amir for explaining and discussing aspects of overlayfs with me. I'd like to especially thank Seth Forshee because he provided a lot of good analysis, suggestions, and participated in short-notice discussions in both chat and video for some nitty-gritty technical details. This series can be found and pulled from the three usual locations: https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git/log/?h=idmapped_mounts https://github.com/brauner/linux/tree/idmapped_mounts https://gitlab.com/brauner/linux/-/commits/idmapped_mounts Thanks! Christian Christian Brauner (37): namespace: take lock_mount_hash() directly when changing flags mount: make {lock,unlock}_mount_hash() static namespace: only take read lock in do_reconfigure_mnt() fs: add mount_setattr() tests: add mount_setattr() selftests fs: add id translation helpers mount: attach mappings to mounts capability: handle idmapped mounts namei: add idmapped mount aware permission helpers inode: add idmapped mount aware init and permission helpers attr: handle idmapped mounts acl: handle idmapped mounts commoncap: handle idmapped mounts stat: handle idmapped mounts namei: handle idmapped mounts in may_*() helpers namei: introduce struct renamedata namei: prepare for idmapped mounts open: handle idmapped mounts in do_truncate() open: handle idmapped mounts af_unix: handle idmapped mounts utimes: handle idmapped mounts fcntl: handle idmapped mounts notify: handle idmapped mounts init: handle idmapped mounts ioctl: handle idmapped mounts would_dump: handle idmapped mounts exec: handle idmapped mounts fs: add helpers for idmap mounts apparmor: handle idmapped mounts audit: handle idmapped mounts ima: handle idmapped mounts fat: handle idmapped mounts ext4: support idmapped mounts ecryptfs: do not mount on top of idmapped mounts overlayfs: do not mount on top of idmapped mounts fs: introduce MOUNT_ATTR_IDMAP tests: add vfs/idmapped mounts test suite Tycho Andersen (2): xattr: handle idmapped mounts selftests: add idmapped mounts xattr selftest Documentation/filesystems/locking.rst | 6 +- Documentation/filesystems/porting.rst | 2 + Documentation/filesystems/vfs.rst | 17 +- arch/alpha/kernel/syscalls/syscall.tbl | 1 + arch/arm/tools/syscall.tbl | 1 + arch/arm64/include/asm/unistd32.h | 2 + arch/ia64/kernel/syscalls/syscall.tbl | 1 + arch/m68k/kernel/syscalls/syscall.tbl | 1 + arch/microblaze/kernel/syscalls/syscall.tbl | 1 + arch/mips/kernel/syscalls/syscall_n32.tbl | 1 + arch/mips/kernel/syscalls/syscall_n64.tbl | 1 + arch/mips/kernel/syscalls/syscall_o32.tbl | 1 + arch/parisc/kernel/syscalls/syscall.tbl | 1 + arch/powerpc/kernel/syscalls/syscall.tbl | 1 + arch/powerpc/platforms/cell/spufs/inode.c | 5 +- arch/s390/kernel/syscalls/syscall.tbl | 1 + arch/sh/kernel/syscalls/syscall.tbl | 1 + arch/sparc/kernel/syscalls/syscall.tbl | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + arch/xtensa/kernel/syscalls/syscall.tbl | 1 + drivers/android/binderfs.c | 3 +- drivers/base/devtmpfs.c | 12 +- fs/9p/acl.c | 7 +- fs/9p/v9fs.h | 3 +- fs/9p/v9fs_vfs.h | 2 +- fs/9p/vfs_inode.c | 32 +- fs/9p/vfs_inode_dotl.c | 34 +- fs/9p/xattr.c | 1 + fs/adfs/adfs.h | 3 +- fs/adfs/inode.c | 5 +- fs/affs/affs.h | 10 +- fs/affs/inode.c | 7 +- fs/affs/namei.c | 15 +- fs/afs/dir.c | 34 +- fs/afs/inode.c | 5 +- fs/afs/internal.h | 4 +- fs/afs/security.c | 2 +- fs/afs/xattr.c | 2 + fs/attr.c | 78 +- fs/autofs/root.c | 13 +- fs/bad_inode.c | 31 +- fs/bfs/dir.c | 12 +- fs/btrfs/acl.c | 5 +- fs/btrfs/ctree.h | 3 +- fs/btrfs/inode.c | 41 +- fs/btrfs/ioctl.c | 25 +- fs/btrfs/tests/btrfs-tests.c | 2 +- fs/btrfs/xattr.c | 2 + fs/cachefiles/interface.c | 4 +- fs/cachefiles/namei.c | 19 +- fs/cachefiles/xattr.c | 16 +- fs/ceph/acl.c | 5 +- fs/ceph/dir.c | 23 +- fs/ceph/inode.c | 13 +- fs/ceph/super.h | 8 +- fs/ceph/xattr.c | 1 + fs/cifs/cifsfs.c | 4 +- fs/cifs/cifsfs.h | 18 +- fs/cifs/dir.c | 8 +- fs/cifs/inode.c | 22 +- fs/cifs/link.c | 3 +- fs/cifs/xattr.c | 1 + fs/coda/coda_linux.h | 4 +- fs/coda/dir.c | 18 +- fs/coda/inode.c | 5 +- fs/coda/pioctl.c | 6 +- fs/configfs/configfs_internal.h | 7 +- fs/configfs/dir.c | 3 +- fs/configfs/inode.c | 5 +- fs/configfs/symlink.c | 5 +- fs/coredump.c | 12 +- fs/crypto/policy.c | 2 +- fs/debugfs/inode.c | 9 +- fs/ecryptfs/crypto.c | 4 +- fs/ecryptfs/inode.c | 74 +- fs/ecryptfs/main.c | 6 + fs/ecryptfs/mmap.c | 4 +- fs/efivarfs/file.c | 2 +- fs/efivarfs/inode.c | 4 +- fs/erofs/inode.c | 2 +- fs/exec.c | 12 +- fs/exfat/exfat_fs.h | 3 +- fs/exfat/file.c | 9 +- fs/exfat/namei.c | 13 +- fs/ext2/acl.c | 5 +- fs/ext2/acl.h | 3 +- fs/ext2/ext2.h | 2 +- fs/ext2/ialloc.c | 2 +- fs/ext2/inode.c | 11 +- fs/ext2/ioctl.c | 6 +- fs/ext2/namei.c | 22 +- fs/ext2/xattr_security.c | 1 + fs/ext2/xattr_trusted.c | 1 + fs/ext2/xattr_user.c | 1 + fs/ext4/Kconfig | 9 + fs/ext4/acl.c | 5 +- fs/ext4/acl.h | 3 +- fs/ext4/ext4.h | 15 +- fs/ext4/ialloc.c | 7 +- fs/ext4/inode.c | 14 +- fs/ext4/ioctl.c | 18 +- fs/ext4/namei.c | 52 +- fs/ext4/super.c | 6 +- fs/ext4/xattr_hurd.c | 1 + fs/ext4/xattr_security.c | 1 + fs/ext4/xattr_trusted.c | 1 + fs/ext4/xattr_user.c | 1 + fs/f2fs/acl.c | 5 +- fs/f2fs/acl.h | 3 +- fs/f2fs/f2fs.h | 3 +- fs/f2fs/file.c | 23 +- fs/f2fs/namei.c | 26 +- fs/f2fs/xattr.c | 4 +- fs/fat/fat.h | 3 +- fs/fat/file.c | 20 +- fs/fat/namei_msdos.c | 15 +- fs/fat/namei_vfat.c | 15 +- fs/fcntl.c | 3 +- fs/fuse/acl.c | 3 +- fs/fuse/dir.c | 41 +- fs/fuse/fuse_i.h | 4 +- fs/fuse/xattr.c | 2 + fs/gfs2/acl.c | 5 +- fs/gfs2/acl.h | 3 +- fs/gfs2/file.c | 4 +- fs/gfs2/inode.c | 54 +- fs/gfs2/inode.h | 2 +- fs/gfs2/xattr.c | 1 + fs/hfs/attr.c | 1 + fs/hfs/dir.c | 13 +- fs/hfs/hfs_fs.h | 2 +- fs/hfs/inode.c | 7 +- fs/hfsplus/dir.c | 25 +- fs/hfsplus/inode.c | 11 +- fs/hfsplus/ioctl.c | 2 +- fs/hfsplus/xattr.c | 1 + fs/hfsplus/xattr_security.c | 1 + fs/hfsplus/xattr_trusted.c | 1 + fs/hfsplus/xattr_user.c | 1 + fs/hostfs/hostfs_kern.c | 31 +- fs/hpfs/hpfs_fn.h | 2 +- fs/hpfs/inode.c | 7 +- fs/hpfs/namei.c | 20 +- fs/hugetlbfs/inode.c | 31 +- fs/init.c | 21 +- fs/inode.c | 38 +- fs/internal.h | 9 + fs/jffs2/acl.c | 5 +- fs/jffs2/acl.h | 3 +- fs/jffs2/dir.c | 32 +- fs/jffs2/fs.c | 7 +- fs/jffs2/os-linux.h | 2 +- fs/jffs2/security.c | 1 + fs/jffs2/xattr_trusted.c | 1 + fs/jffs2/xattr_user.c | 1 + fs/jfs/acl.c | 5 +- fs/jfs/file.c | 9 +- fs/jfs/ioctl.c | 2 +- fs/jfs/jfs_acl.h | 3 +- fs/jfs/jfs_inode.c | 2 +- fs/jfs/jfs_inode.h | 2 +- fs/jfs/namei.c | 21 +- fs/jfs/xattr.c | 2 + fs/kernfs/dir.c | 7 +- fs/kernfs/inode.c | 15 +- fs/kernfs/kernfs-internal.h | 5 +- fs/libfs.c | 20 +- fs/minix/bitmap.c | 2 +- fs/minix/file.c | 7 +- fs/minix/inode.c | 2 +- fs/minix/namei.c | 25 +- fs/mount.h | 10 - fs/namei.c | 317 +- fs/namespace.c | 473 ++- fs/nfs/dir.c | 23 +- fs/nfs/inode.c | 5 +- fs/nfs/internal.h | 10 +- fs/nfs/namespace.c | 7 +- fs/nfs/nfs3_fs.h | 3 +- fs/nfs/nfs3acl.c | 3 +- fs/nfs/nfs4proc.c | 3 + fs/nfsd/nfs2acl.c | 4 +- fs/nfsd/nfs3acl.c | 4 +- fs/nfsd/nfs4acl.c | 4 +- fs/nfsd/nfs4recover.c | 6 +- fs/nfsd/nfsfh.c | 2 +- fs/nfsd/nfsproc.c | 2 +- fs/nfsd/vfs.c | 47 +- fs/nilfs2/inode.c | 13 +- fs/nilfs2/ioctl.c | 2 +- fs/nilfs2/namei.c | 20 +- fs/nilfs2/nilfs.h | 4 +- fs/notify/fanotify/fanotify_user.c | 2 +- fs/notify/inotify/inotify_user.c | 3 +- fs/ntfs/inode.c | 2 +- fs/ocfs2/acl.c | 5 +- fs/ocfs2/acl.h | 3 +- fs/ocfs2/dlmfs/dlmfs.c | 17 +- fs/ocfs2/file.c | 13 +- fs/ocfs2/file.h | 5 +- fs/ocfs2/ioctl.c | 2 +- fs/ocfs2/namei.c | 21 +- fs/ocfs2/refcounttree.c | 4 +- fs/ocfs2/xattr.c | 3 + fs/omfs/dir.c | 13 +- fs/omfs/file.c | 7 +- fs/omfs/inode.c | 2 +- fs/open.c | 52 +- fs/orangefs/acl.c | 5 +- fs/orangefs/inode.c | 15 +- fs/orangefs/namei.c | 12 +- fs/orangefs/orangefs-kernel.h | 7 +- fs/orangefs/xattr.c | 1 + fs/overlayfs/copy_up.c | 20 +- fs/overlayfs/dir.c | 31 +- fs/overlayfs/file.c | 6 +- fs/overlayfs/inode.c | 21 +- fs/overlayfs/overlayfs.h | 40 +- fs/overlayfs/super.c | 27 +- fs/overlayfs/util.c | 4 +- fs/posix_acl.c | 78 +- fs/proc/base.c | 24 +- fs/proc/fd.c | 4 +- fs/proc/fd.h | 3 +- fs/proc/generic.c | 9 +- fs/proc/internal.h | 2 +- fs/proc/proc_net.c | 2 +- fs/proc/proc_sysctl.c | 12 +- fs/proc/root.c | 2 +- fs/proc_namespace.c | 1 + fs/ramfs/file-nommu.c | 9 +- fs/ramfs/inode.c | 18 +- fs/reiserfs/acl.h | 3 +- fs/reiserfs/inode.c | 7 +- fs/reiserfs/ioctl.c | 4 +- fs/reiserfs/namei.c | 21 +- fs/reiserfs/reiserfs.h | 3 +- fs/reiserfs/xattr.c | 12 +- fs/reiserfs/xattr.h | 2 +- fs/reiserfs/xattr_acl.c | 7 +- fs/reiserfs/xattr_security.c | 3 +- fs/reiserfs/xattr_trusted.c | 3 +- fs/reiserfs/xattr_user.c | 3 +- fs/remap_range.c | 7 +- fs/stat.c | 10 +- fs/sysv/file.c | 7 +- fs/sysv/ialloc.c | 2 +- fs/sysv/itree.c | 2 +- fs/sysv/namei.c | 21 +- fs/tracefs/inode.c | 4 +- fs/ubifs/dir.c | 29 +- fs/ubifs/file.c | 5 +- fs/ubifs/ioctl.c | 2 +- fs/ubifs/ubifs.h | 3 +- fs/ubifs/xattr.c | 1 + fs/udf/file.c | 9 +- fs/udf/ialloc.c | 2 +- fs/udf/namei.c | 24 +- fs/udf/symlink.c | 2 +- fs/ufs/ialloc.c | 2 +- fs/ufs/inode.c | 7 +- fs/ufs/namei.c | 19 +- fs/ufs/ufs.h | 3 +- fs/utimes.c | 4 +- fs/vboxsf/dir.c | 12 +- fs/vboxsf/utils.c | 5 +- fs/vboxsf/vfsmod.h | 3 +- fs/verity/enable.c | 2 +- fs/xattr.c | 136 +- fs/xfs/xfs_acl.c | 5 +- fs/xfs/xfs_acl.h | 3 +- fs/xfs/xfs_ioctl.c | 4 +- fs/xfs/xfs_iops.c | 55 +- fs/xfs/xfs_xattr.c | 3 +- fs/zonefs/super.c | 9 +- include/linux/audit.h | 10 +- include/linux/capability.h | 14 +- include/linux/fs.h | 145 +- include/linux/ima.h | 15 +- include/linux/lsm_hook_defs.h | 15 +- include/linux/lsm_hooks.h | 1 + include/linux/mount.h | 14 +- include/linux/nfs_fs.h | 4 +- include/linux/posix_acl.h | 15 +- include/linux/posix_acl_xattr.h | 12 +- include/linux/security.h | 44 +- include/linux/syscalls.h | 3 + include/linux/xattr.h | 30 +- include/uapi/asm-generic/unistd.h | 4 +- include/uapi/linux/mount.h | 25 + ipc/mqueue.c | 16 +- kernel/auditsc.c | 29 +- kernel/bpf/inode.c | 13 +- kernel/capability.c | 14 +- kernel/cgroup/cgroup.c | 2 +- kernel/sys.c | 2 +- mm/madvise.c | 4 +- mm/memcontrol.c | 2 +- mm/mincore.c | 4 +- mm/shmem.c | 45 +- net/socket.c | 6 +- net/unix/af_unix.c | 4 +- security/apparmor/apparmorfs.c | 3 +- security/apparmor/domain.c | 13 +- security/apparmor/file.c | 5 +- security/apparmor/lsm.c | 12 +- security/commoncap.c | 46 +- security/integrity/evm/evm_crypto.c | 11 +- security/integrity/evm/evm_main.c | 4 +- security/integrity/evm/evm_secfs.c | 2 +- security/integrity/ima/ima.h | 19 +- security/integrity/ima/ima_api.c | 10 +- security/integrity/ima/ima_appraise.c | 22 +- security/integrity/ima/ima_asymmetric_keys.c | 2 +- security/integrity/ima/ima_main.c | 28 +- security/integrity/ima/ima_policy.c | 17 +- security/integrity/ima/ima_queue_keys.c | 2 +- security/security.c | 25 +- security/selinux/hooks.c | 22 +- security/smack/smack_lsm.c | 18 +- tools/include/uapi/asm-generic/unistd.h | 4 +- tools/testing/selftests/Makefile | 1 + .../testing/selftests/idmap_mounts/.gitignore | 2 + tools/testing/selftests/idmap_mounts/Makefile | 12 + tools/testing/selftests/idmap_mounts/config | 1 + tools/testing/selftests/idmap_mounts/core.c | 3476 +++++++++++++++++ .../testing/selftests/idmap_mounts/internal.h | 127 + tools/testing/selftests/idmap_mounts/utils.c | 136 + tools/testing/selftests/idmap_mounts/utils.h | 17 + tools/testing/selftests/idmap_mounts/xattr.c | 172 + .../selftests/mount_setattr/.gitignore | 1 + .../testing/selftests/mount_setattr/Makefile | 7 + tools/testing/selftests/mount_setattr/config | 1 + .../mount_setattr/mount_setattr_test.c | 889 +++++ 335 files changed, 7594 insertions(+), 1570 deletions(-) create mode 100644 tools/testing/selftests/idmap_mounts/.gitignore create mode 100644 tools/testing/selftests/idmap_mounts/Makefile create mode 100644 tools/testing/selftests/idmap_mounts/config create mode 100644 tools/testing/selftests/idmap_mounts/core.c create mode 100644 tools/testing/selftests/idmap_mounts/internal.h create mode 100644 tools/testing/selftests/idmap_mounts/utils.c create mode 100644 tools/testing/selftests/idmap_mounts/utils.h create mode 100644 tools/testing/selftests/idmap_mounts/xattr.c create mode 100644 tools/testing/selftests/mount_setattr/.gitignore create mode 100644 tools/testing/selftests/mount_setattr/Makefile create mode 100644 tools/testing/selftests/mount_setattr/config create mode 100644 tools/testing/selftests/mount_setattr/mount_setattr_test.c base-commit: 3cea11cd5e3b00d91caf0b4730194039b45c5891