LU-11595 mdt: fix read-on-open for big PAGE_SIZE

[fs/lustre-release.git] / lustre / mdt / mdt_io.c

diff --git a/lustre/mdt/mdt_io.c b/lustre/mdt/mdt_io.c
index 1fc93b9..3124c8c 100644 (file)
--- a/lustre/mdt/mdt_io.c
+++ b/lustre/mdt/mdt_io.c
@@ -1465,9 +1465,26 @@ int mdt_dom_read_on_open(struct mdt_thread_info *mti, struct mdt_device *mdt,
                len = mbo->mbo_dom_size;
                offset = 0;
        } else {
-               int tail = mbo->mbo_dom_size % PAGE_SIZE;
+               int tail, pgbits;
+
+               /* File tail offset must be aligned with larger page size
+                * between client and server, so the maximum page size is
+                * used here to align offset.
+                *
+                * NB: DOM feature was introduced when server supports pagebits
+                * already, so it should be always non-zero value. Report error
+                * if it is not for some reason.
+                */
+               if (!req->rq_export->exp_target_data.ted_pagebits) {
+                       CERROR("%s: client page bits are not saved on server\n",
+                              mdt_obd_name(mdt));
+                       RETURN(0);
+               }
+               pgbits = max_t(int, PAGE_SHIFT,
+                              req->rq_export->exp_target_data.ted_pagebits);
+               tail = mbo->mbo_dom_size % (1 << pgbits);
 
-               /* no tail or tail can't fit in reply */
+               /* no partial tail or tail can't fit in reply */
                if (tail == 0 || len < tail)
                        RETURN(0);
 
@@ -1482,22 +1499,23 @@ int mdt_dom_read_on_open(struct mdt_thread_info *mti, struct mdt_device *mdt,
                GOTO(out, rc = -E2BIG);
        }
 
-       /* re-take MDT_BODY buffer after the buffer growing above */
+       /* re-take MDT_BODY and NIOBUF_INLINE buffers after the buffer grow */
        mbo = req_capsule_server_get(pill, &RMF_MDT_BODY);
        fid = &mbo->mbo_fid1;
        if (!fid_is_sane(fid))
-               RETURN(0);
+               GOTO(out, rc = -EINVAL);
 
        rnb = req_capsule_server_get(tsi->tsi_pill, &RMF_NIOBUF_INLINE);
        if (rnb == NULL)
                GOTO(out, rc = -EPROTO);
+
        buf = (char *)rnb + sizeof(*rnb);
        rnb->rnb_len = len;
        rnb->rnb_offset = offset;
 
        mo = dt_locate(env, dt, fid);
        if (IS_ERR(mo))
-               GOTO(out, rc = PTR_ERR(mo));
+               GOTO(out_rnb, rc = PTR_ERR(mo));
        LASSERT(mo != NULL);
 
        dt_read_lock(env, mo, 0);
@@ -1535,11 +1553,14 @@ int mdt_dom_read_on_open(struct mdt_thread_info *mti, struct mdt_device *mdt,
        }
        CDEBUG(D_INFO, "Read %i (wanted %u) bytes from %llu\n", copied,
               len, offset);
-       if (copied < len)
+       if (copied < len) {
                CWARN("%s: read %i bytes for "DFID
                      " but wanted %u, is size wrong?\n",
                      tsi->tsi_exp->exp_obd->obd_name, copied,
                      PFID(&tsi->tsi_fid), len);
+               /* Ignore partially copied data */
+               copied = 0;
+       }
        EXIT;
 buf_put:
        dt_bufs_put(env, mo, lnb, nr_local);
@@ -1548,9 +1569,15 @@ free:
 unlock:
        dt_read_unlock(env, mo);
        lu_object_put(env, &mo->do_lu);
+out_rnb:
+       rnb->rnb_len = copied;
 out:
-       if (rnb != NULL)
-               rnb->rnb_len = copied;
+       /* Don't fail OPEN request if read-on-open is failed, but drop
+        * a message in log about the error.
+        */
+       if (rc)
+               CDEBUG(D_INFO, "Read-on-open is failed, rc = %d", rc);
+
        RETURN(0);
 }