From 3fb97e25b194e92112077385b10381801e02ddb9 Mon Sep 17 00:00:00 2001 From: Samuel Just Date: Tue, 24 Mar 2015 15:14:34 -0700 Subject: [PATCH] ReplicatedPG: trim backfill intervals based on peer's last_backfill_started Otherwise, we fail to trim the peer's last_backfill_started and get bug 11199. 1) osd 4 backfills up to 31bccdb2/mira01213209-286/head (henceforth: foo) 2) Interval change happens 3) osd 0 now finds itself backfilling to 4 (lb=foo) and osd.5 (lb=b6670ba2/mira01213209-160/snapdir//1, henceforth: bar) 4) recover_backfill causes both 4 and 5 to scan forward, so 4 has an interval starting at foo, 5 has an interval starting at bar. 5) Once those have come back, recover_backfill attempts to trim off the last_backfill_started, but 4's interval starts after that, so foo remains in osd 4's interval (this is the bug) 7) We serve a copyfrom on foo (sent to 4 as well). 8) We eventually get to foo in the backfilling. Normally, they would have the same version, but of course we don't update osd.4's interval from the log since it should not have received writes in that interval. Thus, we end up trying to recover foo on osd.4 anyway. 9) But, an interval change happens between removing foo from osd.4 and completing the recovery, leaving osd.4 without foo, but with lb >= foo Fixes: #11199 Backport: firefly Signed-off-by: Samuel Just (cherry picked from commit 1388d6bd949a18e8ac0aecb0eb79ffb93d316879) --- src/osd/ReplicatedPG.cc | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc index 25b026961cf..5fa930cd2a6 100644 --- a/src/osd/ReplicatedPG.cc +++ b/src/osd/ReplicatedPG.cc @@ -10253,7 +10253,8 @@ int ReplicatedPG::recover_backfill( for (set::iterator i = backfill_targets.begin(); i != backfill_targets.end(); ++i) { - peer_backfill_info[*i].trim_to(last_backfill_started); + peer_backfill_info[*i].trim_to( + MAX(peer_info[*i].last_backfill, last_backfill_started)); } backfill_info.trim_to(last_backfill_started); -- 2.47.3