Messages in this thread Patch in this message | | | Date | Fri, 22 Jun 2012 10:59:48 -0400 | From | Mike Snitzer <> | Subject | [PATCH] dm thin: reinstate missing mempool_free in cell_release_singleton |
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Hi Greg,
3.3-stable pulled in upstream commit 6f94a4c45a6f744383f9f695dde019998db3df55 (dm thin: fix stacked bi_next usage)
But later in the 3.4 development window it was determined that that commit introduced a significant leak. The following upstream commit fixes it (but unfortunately didn't cc: stable).
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From: Mike Snitzer <snitzer@redhat.com>
commit 03aaae7cdc71bc306888440b1f569d463e917b6d upstream.
Fix a significant memory leak inadvertently introduced during simplification of cell_release_singleton() in commit 6f94a4c45a6f744383f9f695dde019998db3df55 ("dm thin: fix stacked bi_next usage").
A cell's hlist_del() must be accompanied by a mempool_free(). Use __cell_release() to do this, like before.
Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> --- drivers/md/dm-thin.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 213ae32..301db0f 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -279,8 +279,10 @@ static void __cell_release(struct cell *cell, struct bio_list *inmates) hlist_del(&cell->list); - bio_list_add(inmates, cell->holder); - bio_list_merge(inmates, &cell->bios); + if (inmates) { + bio_list_add(inmates, cell->holder); + bio_list_merge(inmates, &cell->bios); + } mempool_free(cell, prison->cell_pool); } @@ -303,9 +305,10 @@ static void cell_release(struct cell *cell, struct bio_list *bios) */ static void __cell_release_singleton(struct cell *cell, struct bio *bio) { - hlist_del(&cell->list); BUG_ON(cell->holder != bio); BUG_ON(!bio_list_empty(&cell->bios)); + + __cell_release(cell, NULL); } static void cell_release_singleton(struct cell *cell, struct bio *bio) -- 1.7.4.4
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