From 06f9cc12caa862f5bc86ebdb4f77568a4bef0167 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Wed, 2 Apr 2014 14:59:08 -0400 Subject: [PATCH] nfsd4: don't create unnecessary mask acl Any setattr of the ACL attribute, even if it sets just the basic 3-ACE ACL exactly as it was returned from a file with only mode bits, creates a mask entry, and it is only the mask, not group, entry that is changed by subsequent modifications of the mode bits. So, for example, it's surprising that GROUP@ is left without read or write permissions after a chmod 0666: touch test chmod 0600 test nfs4_getfacl test A::OWNER@:rwatTcCy A::GROUP@:tcy A::EVERYONE@:tcy nfs4_getfacl test | nfs4_setfacl -S - test # chmod 0666 test nfs4_getfacl test A::OWNER@:rwatTcCy A::GROUP@:tcy D::GROUP@:rwa A::EVERYONE@:rwatcy So, let's stop creating the unnecessary mask ACL. A mask will still be created on non-trivial ACLs (ACLs with actual named user and group ACEs), so the odd posix-acl behavior of chmod modifying only the mask will still be left in that case; but that's consistent with local behavior. Reported-by: Soumya Koduri Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4acl.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c index d190e33d0ec..6f3f392d48a 100644 --- a/fs/nfsd/nfs4acl.c +++ b/fs/nfsd/nfs4acl.c @@ -542,7 +542,10 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) * up setting a 3-element effective posix ACL with all * permissions zero. */ - nace = 4 + state->users->n + state->groups->n; + if (!state->users->n && !state->groups->n) + nace = 3; + else /* Note we also include a MASK ACE in this case: */ + nace = 4 + state->users->n + state->groups->n; pacl = posix_acl_alloc(nace, GFP_KERNEL); if (!pacl) return ERR_PTR(-ENOMEM); @@ -586,9 +589,11 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) add_to_mask(state, &state->groups->aces[i].perms); } - pace++; - pace->e_tag = ACL_MASK; - low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); + if (!state->users->n && !state->groups->n) { + pace++; + pace->e_tag = ACL_MASK; + low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); + } pace++; pace->e_tag = ACL_OTHER; -- 2.41.0