On Tue, Feb 23, 2021 at 05:52:50PM -0500, Vivek Goyal wrote: > Fuse protocl wants file server to opt in for FUSE_POSIX_ACL if posix > acls are to be enabled. Right now virtiofsd does not enable it. This > patch opts in for FUSE_POSIX_ACL if xattr support is enabled. > > 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. > > So this patch also opts in for FUSE_DONT_MASK if posix acls are enabled > and changes umask to caller umask before file creation and restores > original umask after file creation is done. > > This should fix fstest generic/099. > > Reported-by: Luis Henriques <lhenriq...@suse.de> > Signed-off-by: Vivek Goyal <vgo...@redhat.com> > --- > tools/virtiofsd/passthrough_ll.c | 29 +++++++++++++++++++++++------ > 1 file changed, 23 insertions(+), 6 deletions(-)
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
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