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| author | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2019-12-16 13:57:41 +0200 |
|---|---|---|
| committer | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2019-12-16 13:57:41 +0200 |
| commit | 741b884353e4803abc15d4392ad287b0d5953fc4 (patch) | |
| tree | d5504ba96f84461aa8ee79ca77f6a767e7be55d2 /src/backend/access/gist/gist.c | |
| parent | 502423180a8cc9214861bffcb8405a42f146f160 (diff) | |
| download | postgresql-741b884353e4803abc15d4392ad287b0d5953fc4.tar.gz postgresql-741b884353e4803abc15d4392ad287b0d5953fc4.zip | |
Fix yet another crash in page split during GiST index creation.
Commit a7ee7c8513 fixed a bug in GiST page split during index creation,
where we failed to re-find the position of a downlink after the page
containing it was split. However, that fix was incomplete; the other call
to gistinserttuples() in the same function needs to also clear
'downlinkoffnum'.
Fixes bug #16134 reported by Alexander Lakhin, for real this time. The
previous fix was enough to fix the crash with the reproducer script for
bug #16162, but the original script for #16134 was still crashing.
Backpatch to v12, like the previous incomplete fix.
Discussion: https://www.postgresql.org/message-id/d869f537-abe4-d2ea-0510-38cd053f5152%40gmail.com
Diffstat (limited to 'src/backend/access/gist/gist.c')
| -rw-r--r-- | src/backend/access/gist/gist.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c index b87facb2fa9..a259c80616d 100644 --- a/src/backend/access/gist/gist.c +++ b/src/backend/access/gist/gist.c @@ -1325,10 +1325,9 @@ gistfinishsplit(GISTInsertState *state, GISTInsertStack *stack, * downlink for the original page as one operation. */ LockBuffer(stack->parent->buffer, GIST_EXCLUSIVE); - gistFindCorrectParent(state->r, stack); /* - * insert downlinks for the siblings from right to left, until there are + * Insert downlinks for the siblings from right to left, until there are * only two siblings left. */ for (int pos = list_length(splitinfo) - 1; pos > 1; pos--) @@ -1336,17 +1335,17 @@ gistfinishsplit(GISTInsertState *state, GISTInsertStack *stack, right = (GISTPageSplitInfo *) list_nth(splitinfo, pos); left = (GISTPageSplitInfo *) list_nth(splitinfo, pos - 1); + gistFindCorrectParent(state->r, stack); if (gistinserttuples(state, stack->parent, giststate, &right->downlink, 1, InvalidOffsetNumber, left->buf, right->buf, false, false)) { /* - * If the parent page was split, need to relocate the original - * parent pointer. + * If the parent page was split, the existing downlink might + * have moved. */ stack->downlinkoffnum = InvalidOffsetNumber; - gistFindCorrectParent(state->r, stack); } /* gistinserttuples() released the lock on right->buf. */ } @@ -1361,13 +1360,21 @@ gistfinishsplit(GISTInsertState *state, GISTInsertStack *stack, */ tuples[0] = left->downlink; tuples[1] = right->downlink; - gistinserttuples(state, stack->parent, giststate, - tuples, 2, - stack->downlinkoffnum, - left->buf, right->buf, - true, /* Unlock parent */ - unlockbuf /* Unlock stack->buffer if caller wants that */ - ); + gistFindCorrectParent(state->r, stack); + if (gistinserttuples(state, stack->parent, giststate, + tuples, 2, + stack->downlinkoffnum, + left->buf, right->buf, + true, /* Unlock parent */ + unlockbuf /* Unlock stack->buffer if caller wants that */ + )) + { + /* + * If the parent page was split, the downlink might have moved. + */ + stack->downlinkoffnum = InvalidOffsetNumber; + } + Assert(left->buf == stack->buffer); /* |