LU-4219 mdd: limit os_namelen to the max of NAME_MAX

While running pathconf(".", _PC_NAME_MAX) on ldiskfs-based
Lustre filesystem, it returns 255 (NAME_MAX). However, on
zfs-based Lustre filesystem, it returns 256 (MAXNAMELEN).
Since Lustre can not handle the name length large than
NAME_MAX, this patch limits the value of os_namelen in
mdd_statfs() to the max of NAME_MAX.

Test-Parameters: envdefinitions=SLOW=yes \
mdtfilesystemtype=zfs mdsfilesystemtype=zfs ostfilesystemtype=zfs \
ostcount=2 testlist=posix

Lustre-commit: 7d197837e0d7eb5f40a928a8f6c57270493b8996
Lustre-change: http://review.whamcloud.com/8217

Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Signed-off-by: Jian Yu <jian.yu@intel.com>
Change-Id: I6de2f4c45f33c362b5ff61575f0ebc75477c6b48
Reviewed-on: http://review.whamcloud.com/8276
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>

diff --git a/lustre/mdd/mdd_device.c b/lustre/mdd/mdd_device.c
index c10a9a1..505ab08 100644 (file)
--- a/lustre/mdd/mdd_device.c
+++ b/lustre/mdd/mdd_device.c
@@ -927,16 +927,18 @@ static int mdd_root_get(const struct lu_env *env,
  * No permission check is needed.
  */
 static int mdd_statfs(const struct lu_env *env, struct md_device *m,
-                      struct obd_statfs *sfs)
+                     struct obd_statfs *sfs)
 {
-        struct mdd_device *mdd = lu2mdd_dev(&m->md_lu_dev);
-        int rc;
+       struct mdd_device *mdd = lu2mdd_dev(&m->md_lu_dev);
+       int rc;
 
-        ENTRY;
+       ENTRY;
 
-        rc = mdd_child_ops(mdd)->dt_statfs(env, mdd->mdd_child, sfs);
+       rc = mdd_child_ops(mdd)->dt_statfs(env, mdd->mdd_child, sfs);
 
-        RETURN(rc);
+       sfs->os_namelen = min_t(__u32, sfs->os_namelen, NAME_MAX);
+
+       RETURN(rc);
 }
 
 /*