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List: drbd-cvs
Subject: [DRBD-cvs] svn commit by lars - r2377 - trunk/drbd - work on the
From: drbd-cvs () linbit ! com
Date: 2006-08-18 16:13:51
Message-ID: 20060818161351.9671D2D99849 () mail ! linbit ! com
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Author: lars
Date: 2006-08-18 18:13:50 +0200 (Fri, 18 Aug 2006)
New Revision: 2377
Modified:
trunk/drbd/drbd_receiver.c
trunk/drbd/drbd_worker.c
Log:
work on the syncer may or may not ignore the agreed-upon max_segment-size
apart from "it still compiles" no test done. I'll have to make up my mind
whether it is worth the hassle. probably not...
Modified: trunk/drbd/drbd_receiver.c
===================================================================
--- trunk/drbd/drbd_receiver.c 2006-08-18 14:09:04 UTC (rev 2376)
+++ trunk/drbd/drbd_receiver.c 2006-08-18 16:13:50 UTC (rev 2377)
@@ -256,31 +256,81 @@
page = drbd_pp_alloc(mdev, gfp_mask);
if (!page) goto fail2;
if (!bio_add_page(bio, page, min_t(int, ds, PAGE_SIZE), 0)) {
- /* if this happens, it indicates we are not doing correct
- * stacking of device limits.
- * or that the syncer (which may choose to ignore the
- * device limits) happend to request something which
- * does not work on this side...
- *
- * if this happens for the _first_ page, however, my
- * understanding is it would indicate a bug in the
- * lower levels, since adding _one_ page is
- * "guaranteed" to work.
+ /*
+ * actually:
+ drbd_pp_free(page);
+ goto fail2;
+ * But see below.
*/
+ break;
+ }
+ ds -= min_t(int, ds, PAGE_SIZE);
+ }
+
+ /* D_ASSERT( data_size == bio->bi_size); */
+ if (ds) {
+ /*
+ * bio_add_page failed.
+ *
+ * if this happens, it indicates we are not doing correct
+ * stacking of device limits.
+ *
+ * ---
+ * this may also happen on the SyncSource for syncer requests:
+ * for performance, the syncer may choose to ignore the
+ * agreed-upon device limits (max_segment_size may be
+ * arbitrarily set to PAGE_SIZE because the lower level device
+ * happens to have a merge_bvec_fn).
+ *
+ * we would then just "split" the request here,
+ * and then send multiple RSDataReply packets to the peer.
+ *
+ * FIXME to implement that, we'd need ot be able to
+ * "return several Tl_epoch_entry" here,
+ * so we'd need to either recurse, or add more state to the
+ * return valud of this function.
+ * or let the caller check e->ee_size against what he requested,
+ * and reiterate there.
+ *
+ * It is probably just not worth the hassle,
+ * but I'll check it in unfinished now anyways.
+ *
+ * TODO
+ * either complete support on this side, or rip it out
+ * and do the one-liner patch in w_make_resync_request
+ * exchanging DRBD_MAX_SEGMENT_SIZE with q->max_segment_size
+ * ---
+ *
+ * if this happens for the _first_ page, however, my
+ * understanding is it would indicate a bug in the lower levels,
+ * since adding _one_ page is "guaranteed" to work.
+ */
+ if (ds < data_size && id == ID_SYNCER) {
+ /* this currently only serves the first part of that
+ * request. you have to restart the syncer...
+ * this is currently still very buggy and get our
+ * housekeeping about in-sync areas completely wrong.
+ */
+ ERR("should have split resync request: "
+ "sector/data_size/rest %llu %u %u\n",
+ (unsigned long long)sector, data_size, ds);
+ } else {
+ /* this should not happen,
+ * if we correctly stacked limits. */
ERR("bio_add_page failed: "
"id/sector/data_size/rest 0x%llx %llu %u %u\n",
(unsigned long long)id,
(unsigned long long)sector, data_size, ds);
- break;
+ drbd_pp_free(mdev,page);
+ goto fail2;
}
- ds -= min_t(int, ds, PAGE_SIZE);
}
bio->bi_private = e;
e->mdev = mdev;
e->ee_sector = sector;
e->ee_size = bio->bi_size;
- D_ASSERT( data_size == bio->bi_size);
+
e->private_bio = bio;
e->block_id = id;
INIT_HLIST_NODE(&e->colision);
Modified: trunk/drbd/drbd_worker.c
===================================================================
--- trunk/drbd/drbd_worker.c 2006-08-18 14:09:04 UTC (rev 2376)
+++ trunk/drbd/drbd_worker.c 2006-08-18 16:13:50 UTC (rev 2377)
@@ -322,6 +322,7 @@
next_sector:
size = BM_BLOCK_SIZE;
+ /* as of now, we are the only user of drbd_bm_find_next */
bit = drbd_bm_find_next(mdev);
if (bit == -1UL) {
@@ -347,19 +348,38 @@
}
#if DRBD_MAX_SEGMENT_SIZE > BM_BLOCK_SIZE
- // try to find some adjacent bits...
- while ( drbd_bm_test_bit(mdev,bit+1) == 1 ) {
- // stop if we have the already the maximum req size
- if(size == DRBD_MAX_SEGMENT_SIZE) break;
- // do not leafe the current BM_EXTEND
- if(( (bit+1) & BM_BLOCKS_PER_BM_EXT_MASK ) == 0) break;
+ /* try to find some adjacent bits.
+ * we stop if we have already the maximum req size
+ * or if it the request would cross a 32k boundary
+ * (play more nicely with most raid devices).
+ *
+ * we don't care about the agreed-uppon q->max_segment_size
+ * here, because we don't keep a reference on this side.
+ * the sync source will split the requests approrpiately as
+ * needed, and may send multiple RSDataReply packets.
+ */
+ for (;;) {
+ if (size < DRBD_MAX_SEGMENT_SIZE)
+ break;
+ if ((sector & ~63ULL) + BM_BIT_TO_SECT(2) <= 64ULL)
+ break;
+ // do not cross extent boundaries
+ if (( (bit+1) & BM_BLOCKS_PER_BM_EXT_MASK ) == 0)
+ break;
+ // now, is it actually dirty, after all?
+ if ( drbd_bm_test_bit(mdev,bit+1) == 0 )
+ break;
bit++;
size += BM_BLOCK_SIZE;
i++;
}
- drbd_bm_set_find(mdev,bit+1);
+ /* if we merged some,
+ * reset the offset to start the next drbd_bm_find_next from */
+ if (size > BM_BLOCK_SIZE)
+ drbd_bm_set_find(mdev,bit+1);
#endif
+ /* adjust very last sectors, in case we are oddly sized */
if (sector + (size>>9) > capacity) size = (capacity-sector)<<9;
inc_rs_pending(mdev);
if(!drbd_send_drequest(mdev,RSDataRequest,
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