I missed a couple lines in the earlier version of this patch that I sent last night - updated one attached. On Mon, Jun 24, 2019 at 2:11 AM Steve French <smfrench@xxxxxxxxx> wrote: > > See e.g. https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/hh509017(v=ws.10) > > where it describes use of an ACE with special SID S-1-5-88-3 to store the mode. > > Followon patches will add the support for chmod and query_info (stat) > > > > -- > Thanks, > > Steve -- Thanks, Steve
From 0576e2962ca7b30521c236f3d0fd7cea9ff55e1b Mon Sep 17 00:00:00 2001 From: Steve French <stfrench@xxxxxxxxxxxxx> Date: Mon, 24 Jun 2019 02:01:42 -0500 Subject: [PATCH] smb3: add new mount option to retrieve mode from special ACE There is a special ACE used by some servers to allow the mode bits to be stored. This can be especially helpful in scenarios in which the client is trusted, and access checking on the client vs the POSIX mode bits is sufficient. Add mount option to allow enabling this behavior. Follow on patch will add support for chmod and queryinfo (stat) by retrieving the POSIX mode bits from the special ACE, SID: S-1-5-88-3 See e.g. https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/hh509017(v=ws.10) Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> --- fs/cifs/cifs_fs_sb.h | 1 + fs/cifs/cifsfs.c | 2 ++ fs/cifs/cifsglob.h | 3 ++- fs/cifs/connect.c | 8 +++++++- 4 files changed, 12 insertions(+), 2 deletions(-) diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h index afa56237a0c3..744e48bdcb6c 100644 --- a/fs/cifs/cifs_fs_sb.h +++ b/fs/cifs/cifs_fs_sb.h @@ -52,6 +52,7 @@ #define CIFS_MOUNT_UID_FROM_ACL 0x2000000 /* try to get UID via special SID */ #define CIFS_MOUNT_NO_HANDLE_CACHE 0x4000000 /* disable caching dir handles */ #define CIFS_MOUNT_NO_DFS 0x8000000 /* disable DFS resolving */ +#define CIFS_MOUNT_MODE_FROM_ACE 0x10000000 /* retrieve mode from special ACE */ struct cifs_sb_info { struct rb_root tlink_tree; diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index dc5fd7a648f0..e33da73bd300 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -526,6 +526,8 @@ cifs_show_options(struct seq_file *s, struct dentry *root) seq_puts(s, ",nobrl"); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_HANDLE_CACHE) seq_puts(s, ",nohandlecache"); + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_ACE) + seq_puts(s, ",modefromace"); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) seq_puts(s, ",cifsacl"); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 16f240911192..90867264ba4e 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -550,6 +550,7 @@ struct smb_vol { bool override_gid:1; bool dynperm:1; bool noperm:1; + bool mode_ace:1; bool no_psx_acl:1; /* set if posix acl support should be disabled */ bool cifs_acl:1; bool backupuid_specified; /* mount option backupuid is specified */ @@ -618,7 +619,7 @@ struct smb_vol { CIFS_MOUNT_MULTIUSER | CIFS_MOUNT_STRICT_IO | \ CIFS_MOUNT_CIFS_BACKUPUID | CIFS_MOUNT_CIFS_BACKUPGID | \ CIFS_MOUNT_UID_FROM_ACL | CIFS_MOUNT_NO_HANDLE_CACHE | \ - CIFS_MOUNT_NO_DFS) + CIFS_MOUNT_NO_DFS | CIFS_MOUNT_MODE_FROM_ACE) /** * Generic VFS superblock mount flags (s_flags) to consider when diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index b8a60060d329..54e2b2652c3d 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -96,7 +96,7 @@ enum { Opt_multiuser, Opt_sloppy, Opt_nosharesock, Opt_persistent, Opt_nopersistent, Opt_resilient, Opt_noresilient, - Opt_domainauto, Opt_rdma, + Opt_domainauto, Opt_rdma, Opt_modeace, /* Mount options which take numeric value */ Opt_backupuid, Opt_backupgid, Opt_uid, @@ -175,6 +175,7 @@ static const match_table_t cifs_mount_option_tokens = { { Opt_serverino, "serverino" }, { Opt_noserverino, "noserverino" }, { Opt_rwpidforward, "rwpidforward" }, + { Opt_modeace, "modefromace" }, { Opt_cifsacl, "cifsacl" }, { Opt_nocifsacl, "nocifsacl" }, { Opt_acl, "acl" }, @@ -1830,6 +1831,9 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, case Opt_rwpidforward: vol->rwpidforward = 1; break; + case Opt_modeace: + vol->mode_ace = 1; + break; case Opt_cifsacl: vol->cifs_acl = 1; break; @@ -3976,6 +3980,8 @@ int cifs_setup_cifs_sb(struct smb_vol *pvolume_info, cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NOPOSIXBRL; if (pvolume_info->rwpidforward) cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RWPIDFORWARD; + if (pvolume_info->mode_ace) + cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_MODE_FROM_ACE; if (pvolume_info->cifs_acl) cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_CIFS_ACL; if (pvolume_info->backupuid_specified) { -- 2.20.1
