From: Noopur Maheshwari <noopur.maheshwari@seagate.com>
Date: Thu, 2 Feb 2017 09:09:31 +0000 (+0530)
Subject: LU-9074 llite: Stop file creation for ro bind mnt
X-Git-Tag: 2.10.0-RC1~9
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=6da95b1d20ebd32eace18f28070b446155588eff

LU-9074 llite: Stop file creation for ro bind mnt

While remounting the bind mount of lustre with read-only, vfs
sets MNT_READONLY in the mnt flags and does not make a call
to lustre. Hence, the change in mnt flags is not reflected in
lustre.

Therefore, file creation goes ahead in lookup operation of
lustre with LOOKUP_CREATE intent set and converted to IT_CREAT.

The fix is to disallow file creation by not setting IT_CREAT
intent when bind mnt pt is readonly and unsetting O_CREAT.

Added a test case to test that files are not created in ro
bind mount point. Files must be created after bind mount point
is converted from ro to rw.

Signed-off-by: Noopur Maheshwari <noopur.maheshwari@seagate.com>
Change-Id: Ic60fb18f539159715049515e264afdf51a00378e
Reviewed-on: https://review.whamcloud.com/25204
Reviewed-by: Andrew Perepechko <andrew.perepechko@seagate.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lustre/llite/namei.c b/lustre/llite/namei.c
index c8bfe98..ef60461 100644
--- a/lustre/llite/namei.c
+++ b/lustre/llite/namei.c
@@ -804,7 +804,7 @@ out_release:
 
 #else /* !HAVE_IOP_ATOMIC_OPEN */
 static struct lookup_intent *
-ll_convert_intent(struct open_intent *oit, int lookup_flags)
+ll_convert_intent(struct open_intent *oit, int lookup_flags, bool is_readonly)
 {
 	struct lookup_intent *it;
 
@@ -814,10 +814,12 @@ ll_convert_intent(struct open_intent *oit, int lookup_flags)
 
 	if (lookup_flags & LOOKUP_OPEN) {
 		it->it_op = IT_OPEN;
-		if (lookup_flags & LOOKUP_CREATE)
+		/* Avoid file creation for ro bind mount point(is_readonly) */
+		if ((lookup_flags & LOOKUP_CREATE) && !is_readonly)
 			it->it_op |= IT_CREAT;
 		it->it_create_mode = (oit->create_mode & S_IALLUGO) | S_IFREG;
-		it->it_flags = ll_namei_to_lookup_intent_flag(oit->flags);
+		it->it_flags = ll_namei_to_lookup_intent_flag(oit->flags &
+						~(is_readonly ? O_CREAT : 0));
 		it->it_flags &= ~MDS_OPEN_FL_INTERNAL;
 	} else {
 		it->it_op = IT_GETATTR;
@@ -851,7 +853,9 @@ static struct dentry *ll_lookup_nd(struct inode *parent, struct dentry *dentry,
 					      MAY_WRITE | MAY_EXEC) == 0))
 				RETURN(NULL);
 
-			it = ll_convert_intent(&nd->intent.open, nd->flags);
+			it = ll_convert_intent(&nd->intent.open, nd->flags,
+				(nd->path.mnt->mnt_flags & MNT_READONLY) ||
+				(nd->path.mnt->mnt_sb->s_flags & MS_RDONLY));
 			if (IS_ERR(it))
 				RETURN((struct dentry *)it);
 		}
diff --git a/lustre/tests/conf-sanity.sh b/lustre/tests/conf-sanity.sh
index 4c1a314..4bca875 100755
--- a/lustre/tests/conf-sanity.sh
+++ b/lustre/tests/conf-sanity.sh
@@ -7416,6 +7416,43 @@ test_104() { # LU-6952
 }
 run_test 104 "Make sure user defined options are reflected in mount"
 
+error_and_umount() {
+	umount $TMP/$tdir
+	rmdir $TMP/$tdir
+	error $*
+}
+
+test_105() {
+	cleanup
+	reformat
+	setup
+	mkdir -p $TMP/$tdir
+	mount --bind $DIR $TMP/$tdir || error "mount bind mnt pt failed"
+	rm -f $TMP/$tdir/$tfile
+	rm -f $TMP/$tdir/${tfile}1
+
+	# Files should not be created in ro bind mount point
+	# remounting from rw to ro
+	mount -o remount,ro $TMP/$tdir ||
+		error_and_umount "readonly remount of bind mnt pt failed"
+	touch $TMP/$tdir/$tfile &&
+		error_and_umount "touch succeeds on ro bind mnt pt"
+	[ -e $TMP/$tdir/$tfile ] &&
+		error_and_umount "file created on ro bind mnt pt"
+
+	# Files should be created in rw bind mount point
+	# remounting from ro to rw
+	mount -o remount,rw $TMP/$tdir ||
+		error_and_umount "read-write remount of bind mnt pt failed"
+	touch $TMP/$tdir/${tfile}1 ||
+		error_and_umount "touch fails on rw bind mnt pt"
+	[ -e $TMP/$tdir/${tfile}1 ] ||
+		error_and_umount "file not created on rw bind mnt pt"
+	umount $TMP/$tdir || error "umount of bind mnt pt failed"
+	rmdir $TMP/$tdir
+}
+run_test 105 "check file creation for ro and rw bind mnt pt"
+
 if ! combined_mgs_mds ; then
 	stop mgs
 fi