cluster/ec: Fix invalid config check for directories

The trusted.ec.config xattr is not defined for directories. However
sometimes it could be requested because the inode type of a directory
can temporarily be IA_INVAL.

Requesting such xattr using the xattrop fop when it doesn't exist,
returns a config value full of 0's, which is invalid and caused some
fops to fail.

This patch filters out this case by ignoring config xattr == 0.

Change-Id: Ied51c35b313ea8c3eeae27812f9bae61d3808e92
BUG: 1293223
Signed-off-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-on: http://review.gluster.org/13446
Smoke: Gluster Build System <jenkins@build.gluster.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Ashish Pandey <aspandey@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/xlators/cluster/ec/src/ec-helpers.c b/xlators/cluster/ec/src/ec-helpers.c
index 01e5e56a9b6..c8f904ac51d 100644
--- a/xlators/cluster/ec/src/ec-helpers.c
+++ b/xlators/cluster/ec/src/ec-helpers.c
@@ -321,6 +321,19 @@ int32_t ec_dict_del_config(dict_t * dict, char * key, ec_config_t * config)
     }
 
     data = ntoh64(*(uint64_t *)ptr);
+    /* Currently we need to get the config xattr for entries of type IA_INVAL.
+     * These entries can later become IA_DIR entries (after inode_link()),
+     * which don't have a config xattr. However, since the xattr is requested
+     * using an xattrop() fop, it will always return a config full of 0's
+     * instead of saying that it doesn't exist.
+     *
+     * We need to filter out this case and consider that a config xattr == 0 is
+     * the same than a non-existant xattr. Otherwise ec_config_check() will
+     * fail.
+     */
+    if (data == 0) {
+        return -ENODATA;
+    }
 
     config->version = (data >> 56) & 0xff;
     if (config->version > EC_CONFIG_VERSION)