staging/lustre/lov: don't crash accessing LOV object with FID{0, 0}

[karo-tx-linux.git] / drivers / staging / lustre / lustre / lov / lov_lock.c

diff --git a/drivers/staging/lustre/lustre/lov/lov_lock.c b/drivers/staging/lustre/lustre/lov/lov_lock.c
index 49e694222ac839416327779de74d25de31b9e38c..f2eca565bddab0130ea80f470458e71c349b8245 100644 (file)
--- a/drivers/staging/lustre/lustre/lov/lov_lock.c
+++ b/drivers/staging/lustre/lustre/lov/lov_lock.c
@@ -308,7 +308,8 @@ static int lov_lock_sub_init(const struct lu_env *env,
                 * XXX for wide striping smarter algorithm is desirable,
                 * breaking out of the loop, early.
                 */
-               if (lov_stripe_intersects(loo->lo_lsm, i,
+               if (likely(r0->lo_sub[i] != NULL) &&
+                   lov_stripe_intersects(loo->lo_lsm, i,
                                          file_start, file_end, &start, &end))
                        nr++;
        }
@@ -326,7 +327,8 @@ static int lov_lock_sub_init(const struct lu_env *env,
         * top-lock.
         */
        for (i = 0, nr = 0; i < r0->lo_nr; ++i) {
-               if (lov_stripe_intersects(loo->lo_lsm, i,
+               if (likely(r0->lo_sub[i] != NULL) &&
+                   lov_stripe_intersects(loo->lo_lsm, i,
                                          file_start, file_end, &start, &end)) {
                        struct cl_lock_descr *descr;
 
@@ -914,10 +916,22 @@ static int lov_lock_stripe_is_matching(const struct lu_env *env,
         */
        start = cl_offset(&lov->lo_cl, descr->cld_start);
        end   = cl_offset(&lov->lo_cl, descr->cld_end + 1) - 1;
-       result = end - start <= lsm->lsm_stripe_size &&
-                stripe == lov_stripe_number(lsm, start) &&
-                stripe == lov_stripe_number(lsm, end);
-       if (result) {
+       result = 0;
+       /* glimpse should work on the object with LOV EA hole. */
+       if (end - start <= lsm->lsm_stripe_size) {
+               int idx;
+
+               idx = lov_stripe_number(lsm, start);
+               if (idx == stripe ||
+                   unlikely(lov_r0(lov)->lo_sub[idx] == NULL)) {
+                       idx = lov_stripe_number(lsm, end);
+                       if (idx == stripe ||
+                           unlikely(lov_r0(lov)->lo_sub[idx] == NULL))
+                               result = 1;
+               }
+       }
+
+       if (result != 0) {
                struct cl_lock_descr *subd = &lov_env_info(env)->lti_ldescr;
                u64 sub_start;
                u64 sub_end;