diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2022-07-27 16:31:30 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-25 11:40:43 +0200 |
| commit | 8641e0bbb5ef8feedec7a5d6377acdc6c46e8116 (patch) | |
| tree | 2bfded22aed127f5b630ab6cb4f544b70f4a9d5b /fs/overlayfs/super.c | |
| parent | 0480540da5a29adb5c8520d60247fb40f9c9e0d8 (diff) | |
ovl: warn if trusted xattr creation fails
[ Upstream commit b10b85fe5149ee8b39fbbf86095b303632dde2cd ]
When mounting overlayfs in an unprivileged user namespace, trusted xattr
creation will fail. This will lead to failures in some file operations,
e.g. in the following situation:
mkdir lower upper work merged
mkdir lower/directory
mount -toverlay -olowerdir=lower,upperdir=upper,workdir=work none merged
rmdir merged/directory
mkdir merged/directory
The last mkdir will fail:
mkdir: cannot create directory 'merged/directory': Input/output error
The cause for these failures is currently extremely non-obvious and hard to
debug. Hence, warn the user and suggest using the userxattr mount option,
if it is not already supplied and xattr creation fails during the
self-check.
Reported-by: Alois Wohlschlager <alois1@gmx-topmail.de>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/overlayfs/super.c')
| -rw-r--r-- | fs/overlayfs/super.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 7bb0a47cb615..9837aaf9caf1 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1413,11 +1413,12 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, */ err = ovl_do_setxattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE, "0", 1); if (err) { + pr_warn("failed to set xattr on upper\n"); ofs->noxattr = true; if (ofs->config.index || ofs->config.metacopy) { ofs->config.index = false; ofs->config.metacopy = false; - pr_warn("upper fs does not support xattr, falling back to index=off,metacopy=off.\n"); + pr_warn("...falling back to index=off,metacopy=off.\n"); } /* * xattr support is required for persistent st_ino. @@ -1425,8 +1426,10 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, */ if (ofs->config.xino == OVL_XINO_AUTO) { ofs->config.xino = OVL_XINO_OFF; - pr_warn("upper fs does not support xattr, falling back to xino=off.\n"); + pr_warn("...falling back to xino=off.\n"); } + if (err == -EPERM && !ofs->config.userxattr) + pr_info("try mounting with 'userxattr' option\n"); err = 0; } else { ovl_do_removexattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE); |