[linux-cifs-client] [PATCH 5/5] [CIFS] silently ignore ownership changes unless unix extensions are enabled or we're faking uid changes

Jeff Layton jlayton at redhat.com
Mon May 12 14:49:58 GMT 2008


CIFS currently allows you to change the ownership of a file, but unless
unix extensions are enabled this change is not passed off to the server.

Have CIFS silently ignore ownership changes that can't be persistently
stored on the server unless the "setuids" option is explicitly
specified.

We could return an error here (-EOPNOTSUPP or something), but this is
how most disk-based windows filesystems on behave on Linux (e.g.  VFAT,
NTFS, etc). With cifsacl support and proper Windows to Unix idmapping
support, we may be able to do this more properly in the future.

Signed-off-by: Jeff Layton <jlayton at redhat.com>
---

 fs/cifs/inode.c |   27 ++++++++++++++++++++-------
 1 files changed, 20 insertions(+), 7 deletions(-)
-------------- next part --------------
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 2e4f158..854f64c 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1524,13 +1524,26 @@ int cifs_setattr(struct dentry *direntry, struct iattr *attrs)
 		} else
 			goto cifs_setattr_exit;
 	}
-	if (attrs->ia_valid & ATTR_UID) {
-		cFYI(1, ("UID changed to %d", attrs->ia_uid));
-		uid = attrs->ia_uid;
-	}
-	if (attrs->ia_valid & ATTR_GID) {
-		cFYI(1, ("GID changed to %d", attrs->ia_gid));
-		gid = attrs->ia_gid;
+
+	/*
+	 * Without unix extensions we can't send ownership changes to the
+	 * server, so silently ignore them. This is consistent with how
+	 * local DOS/Windows filesystems behave (VFAT, NTFS, etc). With
+	 * CIFSACL support + proper Windows to Unix idmapping, we may be
+	 * able to support this in the future.
+	 */
+	if (!pTcon->unix_ext &&
+	    !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) {
+		attrs->ia_valid &= ~(ATTR_UID | ATTR_GID);
+	} else {
+		if (attrs->ia_valid & ATTR_UID) {
+			cFYI(1, ("UID changed to %d", attrs->ia_uid));
+			uid = attrs->ia_uid;
+		}
+		if (attrs->ia_valid & ATTR_GID) {
+			cFYI(1, ("GID changed to %d", attrs->ia_gid));
+			gid = attrs->ia_gid;
+		}
 	}
 
 	time_buf.Attributes = 0;


More information about the linux-cifs-client mailing list