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| author | Timothy Smith <timothy.smith@sun.com> | 2009-03-11 18:14:24 -0600 |
|---|---|---|
| committer | Timothy Smith <timothy.smith@sun.com> | 2009-03-11 18:14:24 -0600 |
| commit | 556135a1a1126443faf4a9508ef1432cb6968df2 (patch) | |
| tree | 91811d26e9c1b41a3c903bbb843230e1e90d8361 /storage/innobase/btr | |
| parent | 5c2114285549efb625ca2dc36dfa6406ca83f3fe (diff) | |
| download | mariadb-git-556135a1a1126443faf4a9508ef1432cb6968df2.tar.gz | |
Applying InnoDB snashot 5.1-ss4350, part 1. Fixes
Bug #42279 Race condition in btr_search_drop_page_hash_when_freed()
Detailed revision comments:
r4032 | marko | 2009-01-23 15:43:51 +0200 (Fri, 23 Jan 2009) | 10 lines
branches/5.1: Merge r4031 from branches/5.0:
btr_search_drop_page_hash_when_freed(): Check if buf_page_get_gen()
returns NULL. The page may have been evicted from the buffer pool
between buf_page_peek_if_search_hashed() and buf_page_get_gen(),
because the buffer pool mutex will be released between these two calls.
(Bug #42279)
rb://82 approved by Heikki Tuuri
Diffstat (limited to 'storage/innobase/btr')
| -rw-r--r-- | storage/innobase/btr/btr0sea.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/storage/innobase/btr/btr0sea.c b/storage/innobase/btr/btr0sea.c index 3482e16497a..84ad0e27110 100644 --- a/storage/innobase/btr/btr0sea.c +++ b/storage/innobase/btr/btr0sea.c @@ -1105,12 +1105,20 @@ btr_search_drop_page_hash_when_freed( page = buf_page_get_gen(space, page_no, RW_S_LATCH, NULL, BUF_GET_IF_IN_POOL, __FILE__, __LINE__, &mtr); + /* Because the buffer pool mutex was released by + buf_page_peek_if_search_hashed(), it is possible that the + block was removed from the buffer pool by another thread + before buf_page_get_gen() got a chance to acquire the buffer + pool mutex again. Thus, we must check for a NULL return. */ + + if (UNIV_LIKELY(page != NULL)) { #ifdef UNIV_SYNC_DEBUG - buf_page_dbg_add_level(page, SYNC_TREE_NODE_FROM_HASH); + buf_page_dbg_add_level(page, SYNC_TREE_NODE_FROM_HASH); #endif /* UNIV_SYNC_DEBUG */ - btr_search_drop_page_hash_index(page); + btr_search_drop_page_hash_index(page); + } mtr_commit(&mtr); } |