cluster/ec: Fix incorrect check for iatt differences

        Backport of http://review.gluster.org/11018

A previous patch (http://review.gluster.org/10974) introduced a
bug that caused that some metadata differences could not be
detected in some circumstances. This could cause that self-heal
is not triggered and the file not repaired.

We also need to consider all differences for lookup requests, even
if there isn't any lock. Special handling of differences in lookup
is already done in lookup specific code.

Change-Id: I88e3678634d848a89f428a37209c31464e42cf8b
BUG: 1225796
Signed-off-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-on: http://review.gluster.org/11027
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

1 files changed, 19 insertions, 5 deletions

diff --git a/xlators/cluster/ec/src/ec-combine.c b/xlators/cluster/ec/src/ec-combine.c
index 6395b223c36..b787d9be303 100644
--- a/xlators/cluster/ec/src/ec-combine.c
+++ b/xlators/cluster/ec/src/ec-combine.c
@@ -131,6 +131,15 @@ ec_iatt_is_trusted(ec_fop_data_t *fop, struct iatt *iatt)
         fop = fop->parent;
     }
 
+    /* Lookups are special requests always done without locks taken but they
+     * require to be able to identify differences between bricks. Special
+     * handling of these differences is already done in lookup specific code
+     * so we shouldn't ignore any difference here and consider all iatt
+     * structures as trusted. */
+    if (fop->id == GF_FOP_LOOKUP) {
+        return _gf_true;
+    }
+
     /* Check if the iatt references an inode locked by the current fop */
     for (i = 0; i < fop->lock_count; i++) {
         ino = gfid_to_ino(fop->locks[i].lock->loc.inode->gfid);
@@ -168,15 +177,20 @@ int32_t ec_iatt_combine(ec_fop_data_t *fop, struct iatt *dst, struct iatt *src,
                          (dst[i].ia_size != src[i].ia_size)) ||
                         (st_mode_from_ia(dst[i].ia_prot, dst[i].ia_type) !=
                          st_mode_from_ia(src[i].ia_prot, src[i].ia_type)))) {
-            if (!ec_iatt_is_trusted(fop, dst)) {
-                /* If the iatt contains information from an inode that is not
-                 * locked, we ignore these differences and don't care which
+            if (ec_iatt_is_trusted(fop, dst)) {
+                /* If the iatt contains information from an inode that is
+                 * locked, these differences are real problems, so we need to
+                 * report them. Otherwise we ignore them and don't care which
                  * data is returned. */
-                failed = _gf_false;
+                failed = _gf_true;
+            } else {
+                gf_log(fop->xl->name, GF_LOG_DEBUG,
+                       "Ignoring iatt differences because inode is not "
+                       "locked");
             }
         }
         if (failed) {
-            gf_log(THIS->name, GF_LOG_WARNING,
+            gf_log(fop->xl->name, GF_LOG_WARNING,
                    "Failed to combine iatt (inode: %lu-%lu, links: %u-%u, "
                    "uid: %u-%u, gid: %u-%u, rdev: %lu-%lu, size: %lu-%lu, "
                    "mode: %o-%o)",