From 4a8b34afa9c94c180d16999e405d380cc0477369 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 27 Jul 2021 12:48:58 +0200 Subject: [PATCH] btrfs: handle ACLs on idmapped mounts Make the ACL code idmapped mount aware. The POSIX default and POSIX access ACLs are the only ACLs other than some specific xattrs that take DAC permissions into account. On an idmapped mount they need to be translated according to the mount's userns. The main change is done to __btrfs_set_acl() which is responsible for translating POSIX ACLs to their final on-disk representation. The btrfs_init_acl() helper does not need to take the idmapped mount into account since it is called in the context of file creation operations (mknod, create, mkdir, symlink, tmpfile) and is used for btrfs_init_inode_security() to copy POSIX default and POSIX access permissions from the parent directory. These ACLs need to be inherited unmodified from the parent directory. This is identical to what we do for ext4 and xfs. Reviewed-by: Josef Bacik Signed-off-by: Christian Brauner Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/acl.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c index d95eb5c8cb37..c9f9789e828f 100644 --- a/fs/btrfs/acl.c +++ b/fs/btrfs/acl.c @@ -53,7 +53,8 @@ struct posix_acl *btrfs_get_acl(struct inode *inode, int type) } static int __btrfs_set_acl(struct btrfs_trans_handle *trans, - struct inode *inode, struct posix_acl *acl, int type) + struct user_namespace *mnt_userns, + struct inode *inode, struct posix_acl *acl, int type) { int ret, size = 0; const char *name; @@ -114,12 +115,12 @@ int btrfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode, umode_t old_mode = inode->i_mode; if (type == ACL_TYPE_ACCESS && acl) { - ret = posix_acl_update_mode(&init_user_ns, inode, + ret = posix_acl_update_mode(mnt_userns, inode, &inode->i_mode, &acl); if (ret) return ret; } - ret = __btrfs_set_acl(NULL, inode, acl, type); + ret = __btrfs_set_acl(NULL, mnt_userns, inode, acl, type); if (ret) inode->i_mode = old_mode; return ret; @@ -140,14 +141,14 @@ int btrfs_init_acl(struct btrfs_trans_handle *trans, return ret; if (default_acl) { - ret = __btrfs_set_acl(trans, inode, default_acl, + ret = __btrfs_set_acl(trans, &init_user_ns, inode, default_acl, ACL_TYPE_DEFAULT); posix_acl_release(default_acl); } if (acl) { if (!ret) - ret = __btrfs_set_acl(trans, inode, acl, + ret = __btrfs_set_acl(trans, &init_user_ns, inode, acl, ACL_TYPE_ACCESS); posix_acl_release(acl); }