posix: delete stale gfid handles in nameless lookup

..in order for self-heal of symlinks to work properly (see BZ for
details).

Backport of https://review.gluster.org/#/c/19070/
Signed-off-by: Ravishankar N <ravishankar@redhat.com>

Change-Id: I9a011d00b07a690446f7fd3589e96f840e8b7501
BUG: 1534847

2 files changed, 81 insertions, 1 deletions

diff --git a/tests/bugs/heal-symlinks.t b/tests/bugs/heal-symlinks.t
new file mode 100644
index 00000000000..ecd2b525be1
--- /dev/null
+++ b/tests/bugs/heal-symlinks.t
@@ -0,0 +1,65 @@
+#!/bin/bash
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../volume.rc
+. $(dirname $0)/../afr.rc
+cleanup;
+
+###############################################################################
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume create $V0 replica 3 $H0:$B0/${V0}{0,1,2}
+TEST $CLI volume set $V0 performance.stat-prefetch off
+TEST $CLI volume start $V0
+
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 --entry-timeout=0 $M0;
+
+cd $M0
+TEST "echo hello_world > FILE"
+TEST ln -s FILE SOFTLINK
+
+# Remove symlink only (not the .glusterfs entry) and trigger named heal.
+TEST rm -f $B0/${V0}2/SOFTLINK
+TEST stat SOFTLINK
+
+# To heal and clear new-entry mark on source bricks.
+TEST $CLI volume heal $V0
+EXPECT_WITHIN $HEAL_TIMEOUT "^0$" get_pending_heal_count $V0
+
+EXPECT 2 stat -c %h  $B0/${V0}2/SOFTLINK
+EXPECT "hello_world" cat $B0/${V0}2/SOFTLINK
+
+cd -
+cleanup
+###############################################################################
+
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume create $V0 disperse 3 redundancy 1  $H0:$B0/${V0}{0,1,2}
+TEST $CLI volume set $V0 performance.stat-prefetch off
+TEST $CLI volume start $V0
+
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 --entry-timeout=0 $M0;
+
+cd $M0
+TEST "echo hello_world > FILE"
+TEST ln -s FILE SOFTLINK
+
+# Remove symlink only (not the .glusterfs entry) and trigger named heal.
+TEST rm -f $B0/${V0}2/SOFTLINK
+TEST stat SOFTLINK
+
+# To heal and clear new-entry mark on source bricks.
+TEST $CLI volume heal $V0
+EXPECT_WITHIN $HEAL_TIMEOUT "^0$" get_pending_heal_count $V0
+
+EXPECT 2 stat -c %h  $B0/${V0}2/SOFTLINK
+TEST kill_brick $V0 $H0 $B0/${V0}0
+cd -
+EXPECT_WITHIN $UMOUNT_TIMEOUT "Y" force_umount $M0
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 --entry-timeout=0 $M0;
+cd $M0
+EXPECT "hello_world" cat SOFTLINK
+
+cd -
+cleanup
+###############################################################################
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 5775152632d..c9fa7f606d9 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -213,7 +213,10 @@ posix_lookup (call_frame_t *frame, xlator_t *this,
         dict_t *    xattr              = NULL;
         char *      real_path          = NULL;
         char *      par_path           = NULL;
+        char        *gfid_path         = NULL;
+        uuid_t      gfid               = {0};
         struct iatt postparent         = {0,};
+        struct stat statbuf            = {0};
         int32_t     gfidless           = 0;
         char        *pgfid_xattr_key   = NULL;
         int32_t     nlink_samepgfid    = 0;
@@ -267,7 +270,19 @@ posix_lookup (call_frame_t *frame, xlator_t *this,
                                 "lstat on %s failed",
                                 real_path ? real_path : "null");
                 }
-
+                if (loc_is_nameless(loc)) {
+                        if (!op_errno)
+                                op_errno = ESTALE;
+                        loc_gfid (loc, gfid);
+                        MAKE_HANDLE_ABSPATH (gfid_path, this, gfid);
+                        op_ret = sys_lstat(gfid_path, &statbuf);
+                        if (op_ret == 0 && statbuf.st_nlink == 1) {
+                                gf_msg (this->name, GF_LOG_WARNING, ESTALE,
+                                        P_MSG_HANDLE_DELETE, "Found stale gfid "
+                                        "handle %s, removing it.", gfid_path);
+                                posix_handle_unset (this, gfid, NULL);
+                        }
+                }
                 entry_ret = -1;
                 goto parent;
         }