this is passing fstests, I'm just hoping for someone who's more familiar with the idmapping stuff to glance at it before I merge - Christain, look reasonable to you? On Sat, Aug 24, 2024 at 09:27:24AM GMT, Hongbo Li wrote: > We enable idmapped mounts for bcachefs. Here, we just pass down > the user_namespace argument from the VFS methods to the relevant > helpers. > > The idmap test in bcachefs is as following: > > ``` > 1. losetup /dev/loop1 bcachefs.img > 2. ./bcachefs format /dev/loop1 > 3. mount -t bcachefs /dev/loop1 /mnt/bcachefs/ > 4. ./mount-idmapped --map-mount b:0:1000:1 /mnt/bcachefs /mnt/idmapped1/ > > ll /mnt/bcachefs > total 2 > drwx------. 2 root root 0 Jun 14 14:10 lost+found > -rw-r--r--. 1 root root 1945 Jun 14 14:12 profile > > ll /mnt/idmapped1/ > > total 2 > drwx------. 2 1000 1000 0 Jun 14 14:10 lost+found > -rw-r--r--. 1 1000 1000 1945 Jun 14 14:12 profile > > Signed-off-by: Hongbo Li <lihongbo22@xxxxxxxxxx> > > --- > v2: > - fix the gid translation when umask S_ISGID > > v1: > - https://lore.kernel.org/all/20240615102038.3110867-1-lihongbo22@xxxxxxxxxx/T/ > --- > fs/bcachefs/fs.c | 50 ++++++++++++++++++++++++++++++++---------------- > 1 file changed, 34 insertions(+), 16 deletions(-) > > diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c > index c50457ba808d..0fcab802d376 100644 > --- a/fs/bcachefs/fs.c > +++ b/fs/bcachefs/fs.c > @@ -350,6 +350,8 @@ __bch2_create(struct mnt_idmap *idmap, > subvol_inum inum; > struct bch_subvolume subvol; > u64 journal_seq = 0; > + kuid_t kuid; > + kgid_t kgid; > int ret; > > /* > @@ -376,13 +378,15 @@ __bch2_create(struct mnt_idmap *idmap, > retry: > bch2_trans_begin(trans); > > + kuid = mapped_fsuid(idmap, i_user_ns(&dir->v)); > + kgid = mapped_fsgid(idmap, i_user_ns(&dir->v)); > ret = bch2_subvol_is_ro_trans(trans, dir->ei_inum.subvol) ?: > bch2_create_trans(trans, > inode_inum(dir), &dir_u, &inode_u, > !(flags & BCH_CREATE_TMPFILE) > ? &dentry->d_name : NULL, > - from_kuid(i_user_ns(&dir->v), current_fsuid()), > - from_kgid(i_user_ns(&dir->v), current_fsgid()), > + from_kuid(i_user_ns(&dir->v), kuid), > + from_kgid(i_user_ns(&dir->v), kgid), > mode, rdev, > default_acl, acl, snapshot_src, flags) ?: > bch2_quota_acct(c, bch_qid(&inode_u), Q_INO, 1, > @@ -800,11 +804,17 @@ static void bch2_setattr_copy(struct mnt_idmap *idmap, > { > struct bch_fs *c = inode->v.i_sb->s_fs_info; > unsigned int ia_valid = attr->ia_valid; > + kuid_t kuid; > + kgid_t kgid; > > - if (ia_valid & ATTR_UID) > - bi->bi_uid = from_kuid(i_user_ns(&inode->v), attr->ia_uid); > - if (ia_valid & ATTR_GID) > - bi->bi_gid = from_kgid(i_user_ns(&inode->v), attr->ia_gid); > + if (ia_valid & ATTR_UID) { > + kuid = from_vfsuid(idmap, i_user_ns(&inode->v), attr->ia_vfsuid); > + bi->bi_uid = from_kuid(i_user_ns(&inode->v), kuid); > + } > + if (ia_valid & ATTR_GID) { > + kgid = from_vfsgid(idmap, i_user_ns(&inode->v), attr->ia_vfsgid); > + bi->bi_gid = from_kgid(i_user_ns(&inode->v), kgid); > + } > > if (ia_valid & ATTR_SIZE) > bi->bi_size = attr->ia_size; > @@ -819,11 +829,11 @@ static void bch2_setattr_copy(struct mnt_idmap *idmap, > if (ia_valid & ATTR_MODE) { > umode_t mode = attr->ia_mode; > kgid_t gid = ia_valid & ATTR_GID > - ? attr->ia_gid > + ? kgid > : inode->v.i_gid; > > - if (!in_group_p(gid) && > - !capable_wrt_inode_uidgid(idmap, &inode->v, CAP_FSETID)) > + if (!in_group_or_capable(idmap, &inode->v, > + make_vfsgid(idmap, i_user_ns(&inode->v), gid))) > mode &= ~S_ISGID; > bi->bi_mode = mode; > } > @@ -839,17 +849,23 @@ int bch2_setattr_nonsize(struct mnt_idmap *idmap, > struct btree_iter inode_iter = { NULL }; > struct bch_inode_unpacked inode_u; > struct posix_acl *acl = NULL; > + kuid_t kuid; > + kgid_t kgid; > int ret; > > mutex_lock(&inode->ei_update_lock); > > qid = inode->ei_qid; > > - if (attr->ia_valid & ATTR_UID) > - qid.q[QTYP_USR] = from_kuid(i_user_ns(&inode->v), attr->ia_uid); > + if (attr->ia_valid & ATTR_UID) { > + kuid = from_vfsuid(idmap, i_user_ns(&inode->v), attr->ia_vfsuid); > + qid.q[QTYP_USR] = from_kuid(i_user_ns(&inode->v), kuid); > + } > > - if (attr->ia_valid & ATTR_GID) > - qid.q[QTYP_GRP] = from_kgid(i_user_ns(&inode->v), attr->ia_gid); > + if (attr->ia_valid & ATTR_GID) { > + kgid = from_vfsgid(idmap, i_user_ns(&inode->v), attr->ia_vfsgid); > + qid.q[QTYP_GRP] = from_kgid(i_user_ns(&inode->v), kgid); > + } > > ret = bch2_fs_quota_transfer(c, inode, qid, ~0, > KEY_TYPE_QUOTA_PREALLOC); > @@ -905,13 +921,15 @@ static int bch2_getattr(struct mnt_idmap *idmap, > { > struct bch_inode_info *inode = to_bch_ei(d_inode(path->dentry)); > struct bch_fs *c = inode->v.i_sb->s_fs_info; > + vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, &inode->v); > + vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, &inode->v); > > stat->dev = inode->v.i_sb->s_dev; > stat->ino = inode->v.i_ino; > stat->mode = inode->v.i_mode; > stat->nlink = inode->v.i_nlink; > - stat->uid = inode->v.i_uid; > - stat->gid = inode->v.i_gid; > + stat->uid = vfsuid_into_kuid(vfsuid); > + stat->gid = vfsgid_into_kgid(vfsgid); > stat->rdev = inode->v.i_rdev; > stat->size = i_size_read(&inode->v); > stat->atime = inode_get_atime(&inode->v); > @@ -2169,7 +2187,7 @@ static struct file_system_type bcache_fs_type = { > .name = "bcachefs", > .init_fs_context = bch2_init_fs_context, > .kill_sb = bch2_kill_sb, > - .fs_flags = FS_REQUIRES_DEV, > + .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, > }; > > MODULE_ALIAS_FS("bcachefs"); > -- > 2.34.1 >
