LU-7890 lov: Ensure correct operation for large object sizes

If a backing filesystem (ZFS) returns that it supports very large
(LLONG_MAX) object sizes, that should be correctly supported.  This
fixes the check for unitialized stripe_maxbytes in
lsm_unpackmd_common(), so that ZFS can return LLONG_MAX and it will be
okay.  This issue is excersized by writing to or past the 2TB boundry
of a singly stripped file.  A regression test is added to check for
this.

Signed-off-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Change-Id: I669096281bd826d69b5e86ada50077740412d268
Reviewed-on: http://review.whamcloud.com/19066
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/lov/lov_ea.c b/lustre/lov/lov_ea.c
index 05bf270..e39acc3 100644 (file)
--- a/lustre/lov/lov_ea.c
+++ b/lustre/lov/lov_ea.c
@@ -157,7 +157,8 @@ static int lsm_unpackmd_common(struct lov_obd *lov,
                               struct lov_ost_data_v1 *objects)
 {
        struct lov_oinfo *loi;
-       loff_t stripe_maxbytes = LLONG_MAX;
+       loff_t min_stripe_maxbytes = 0;
+       loff_t lov_bytes;
        unsigned int stripe_count;
        unsigned int i;
 
@@ -197,18 +198,21 @@ static int lsm_unpackmd_common(struct lov_obd *lov,
                        continue;
                }
 
-               stripe_maxbytes = min_t(loff_t, stripe_maxbytes,
-                                       lov_tgt_maxbytes(
-                                       lov->lov_tgts[loi->loi_ost_idx]));
+               lov_bytes = lov_tgt_maxbytes(lov->lov_tgts[loi->loi_ost_idx]);
+               if (min_stripe_maxbytes == 0 || lov_bytes < min_stripe_maxbytes)
+                       min_stripe_maxbytes = lov_bytes;
        }
 
-       if (stripe_maxbytes == LLONG_MAX)
-               stripe_maxbytes = LUSTRE_EXT3_STRIPE_MAXBYTES;
+       if (min_stripe_maxbytes == 0)
+               min_stripe_maxbytes = LUSTRE_EXT3_STRIPE_MAXBYTES;
 
-       if (lsm->lsm_stripe_count == 0)
-               lsm->lsm_maxbytes = stripe_maxbytes * lov->desc.ld_tgt_count;
+       stripe_count = lsm->lsm_stripe_count ?: lov->desc.ld_tgt_count;
+       lov_bytes = min_stripe_maxbytes * stripe_count;
+
+       if (lov_bytes < min_stripe_maxbytes) /* handle overflow */
+               lsm->lsm_maxbytes = MAX_LFS_FILESIZE;
        else
-               lsm->lsm_maxbytes = stripe_maxbytes * lsm->lsm_stripe_count;
+               lsm->lsm_maxbytes = lov_bytes;
 
        return 0;
 }

diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index 0d8ec04..fdfca1f 100644 (file)
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -13773,6 +13773,19 @@ test_248() {
 }
 run_test 248 "fast read verification"
 
+test_249() { # LU-7890
+       rm -f $DIR/$tfile
+       $SETSTRIPE -c 1 $DIR/$tfile
+
+       [ $(lustre_version_code $SINGLEMDS) -lt $(version_code 2.8.53) ] &&
+       skip "Need at least version 2.8.54"
+
+       # Offset 2T == 4k * 512M
+       dd if=/dev/zero of=$DIR/$tfile bs=4k count=1 seek=512M ||
+               error "dd to 2T offset failed"
+}
+run_test 249 "Write above 2T file size"
+
 test_250() {
        [ "$(facet_fstype ost$(($($GETSTRIPE -i $DIR/$tfile) + 1)))" = "zfs" ] \
         && skip "no 16TB file size limit on ZFS" && return