From: Vivek Goyal <vgoyal@redhat.com>
Date: Mon, 27 Jan 2020 19:01:31 +0000
Subject: [PATCH] virtiofsd: Parse flag FUSE_WRITE_KILL_PRIV

Caller can set FUSE_WRITE_KILL_PRIV in write_flags. Parse it and pass it
to the filesystem.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit f779bc5265e7e7abb13a03d4bfbc74151afc15c2)
---
 tools/virtiofsd/fuse_common.h   | 6 +++++-
 tools/virtiofsd/fuse_lowlevel.c | 4 +++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h
index f8f6433743..686c42c0a5 100644
--- a/tools/virtiofsd/fuse_common.h
+++ b/tools/virtiofsd/fuse_common.h
@@ -93,8 +93,12 @@ struct fuse_file_info {
      */
     unsigned int cache_readdir:1;
 
+    /* Indicates that suid/sgid bits should be removed upon write */
+    unsigned int kill_priv:1;
+
+
     /** Padding.  Reserved for future use*/
-    unsigned int padding:25;
+    unsigned int padding:24;
     unsigned int padding2:32;
 
     /*
diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index 02e1d83038..2d6dc5a680 100644
--- a/tools/virtiofsd/fuse_lowlevel.c
+++ b/tools/virtiofsd/fuse_lowlevel.c
@@ -1142,6 +1142,7 @@ static void do_write(fuse_req_t req, fuse_ino_t nodeid,
     memset(&fi, 0, sizeof(fi));
     fi.fh = arg->fh;
     fi.writepage = (arg->write_flags & FUSE_WRITE_CACHE) != 0;
+    fi.kill_priv = !!(arg->write_flags & FUSE_WRITE_KILL_PRIV);
 
     fi.lock_owner = arg->lock_owner;
     fi.flags = arg->flags;
@@ -1177,7 +1178,8 @@ static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid,
     fi.lock_owner = arg->lock_owner;
     fi.flags = arg->flags;
     fi.fh = arg->fh;
-    fi.writepage = arg->write_flags & FUSE_WRITE_CACHE;
+    fi.writepage = !!(arg->write_flags & FUSE_WRITE_CACHE);
+    fi.kill_priv = !!(arg->write_flags & FUSE_WRITE_KILL_PRIV);
 
     if (ibufv->count == 1) {
         assert(!(tmpbufv.buf[0].flags & FUSE_BUF_IS_FD));