* Vivek Goyal (vgo...@redhat.com) wrote: > When parent directory has default acl and a file is created in that > directory, then umask is ignored and final file permissions are > determined using default acl instead. (man 2 umask). > > Currently, fuse applies the umask and sends modified mode in create > request accordingly. fuse server can set FUSE_DONT_MASK and tell > fuse client to not apply umask and fuse server will take care of > it as needed. > > With posix acls enabled, requirement will be that we want umask > to determine final file mode if parent directory does not have > default acl. > > So if posix acls are enabled, opt in for FUSE_DONT_MASK. virtiofsd > will set umask of the thread doing file creation. And host kernel > should use that umask if parent directory does not have default > acls, otherwise umask does not take affect. > > Miklos mentioned that we already call unshare(CLONE_FS) for > every thread. That means umask has now become property of per > thread and it should be ok to manipulate it in file creation path. > > This patch only adds capability to change umask and restore it. It > does not enable it yet. Next few patches will add capability to enable it > based on if user enabled posix_acl or not. > > This should fix fstest generic/099. > > Reported-by: Luis Henriques <lhenriq...@suse.de> > Signed-off-by: Vivek Goyal <vgo...@redhat.com> > Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com> > --- > tools/virtiofsd/passthrough_ll.c | 22 ++++++++++++++++------ > 1 file changed, 16 insertions(+), 6 deletions(-) > > diff --git a/tools/virtiofsd/passthrough_ll.c > b/tools/virtiofsd/passthrough_ll.c > index 9f5cd98fb5..0c9084ea15 100644 > --- a/tools/virtiofsd/passthrough_ll.c > +++ b/tools/virtiofsd/passthrough_ll.c > @@ -122,6 +122,7 @@ struct lo_inode { > struct lo_cred { > uid_t euid; > gid_t egid; > + mode_t umask; > }; > > enum { > @@ -172,6 +173,8 @@ struct lo_data { > /* An O_PATH file descriptor to /proc/self/fd/ */ > int proc_self_fd; > int user_killpriv_v2, killpriv_v2; > + /* If set, virtiofsd is responsible for setting umask during creation */ > + bool change_umask; > }; > > static const struct fuse_opt lo_opts[] = { > @@ -1134,7 +1137,8 @@ static void lo_lookup(fuse_req_t req, fuse_ino_t > parent, const char *name) > * ownership of caller. > * TODO: What about selinux context? > */ > -static int lo_change_cred(fuse_req_t req, struct lo_cred *old) > +static int lo_change_cred(fuse_req_t req, struct lo_cred *old, > + bool change_umask) > { > int res; > > @@ -1154,11 +1158,14 @@ static int lo_change_cred(fuse_req_t req, struct > lo_cred *old) > return errno_save; > } > > + if (change_umask) { > + old->umask = umask(req->ctx.umask); > + } > return 0; > } > > /* Regain Privileges */ > -static void lo_restore_cred(struct lo_cred *old) > +static void lo_restore_cred(struct lo_cred *old, bool restore_umask) > { > int res; > > @@ -1173,6 +1180,9 @@ static void lo_restore_cred(struct lo_cred *old) > fuse_log(FUSE_LOG_ERR, "setegid(%u): %m\n", old->egid); > exit(1); > } > + > + if (restore_umask) > + umask(old->umask); > } > > static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent, > @@ -1202,7 +1212,7 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t > parent, > return; > } > > - saverr = lo_change_cred(req, &old); > + saverr = lo_change_cred(req, &old, lo->change_umask && !S_ISLNK(mode));
Can you explain what these ISLNK checks are for (insid mknod_symlink, so is that always true or irrelevant?) Dave > if (saverr) { > goto out; > } > @@ -1211,7 +1221,7 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t > parent, > > saverr = errno; > > - lo_restore_cred(&old); > + lo_restore_cred(&old, lo->change_umask && !S_ISLNK(mode)); > > if (res == -1) { > goto out; > @@ -1917,7 +1927,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t > parent, const char *name, > return; > } > > - err = lo_change_cred(req, &old); > + err = lo_change_cred(req, &old, lo->change_umask); > if (err) { > goto out; > } > @@ -1928,7 +1938,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t > parent, const char *name, > fd = openat(parent_inode->fd, name, fi->flags | O_CREAT | O_EXCL, mode); > err = fd == -1 ? errno : 0; > > - lo_restore_cred(&old); > + lo_restore_cred(&old, lo->change_umask); > > /* Ignore the error if file exists and O_EXCL was not given */ > if (err && (err != EEXIST || (fi->flags & O_EXCL))) { > -- > 2.25.4 > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK