From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xue jiufei Date: Mon, 05 Nov 2012 16:45:24 +0800 Subject: [Ocfs2-devel] [PATCH] ocfs2:fix memory leak in dlm_add_migration_mle In-Reply-To: <5093DE48.9090805@oracle.com> References: <50938971.9010805@huawei.com> <5093DE48.9090805@oracle.com> Message-ID: <50977CA4.1080603@huawei.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com Hi Jeff ? 2012/11/2 22:52, Jeff Liu ??: > Hi Jiefei, > > On 11/02/2012 04:50 PM, Xue jiufei wrote: >> After some parallel mount/umount test on ocfs2, we got this: slab error >> in kmem_cache_destroy(): cache `o2dlm_mle': Can't free all objects. >> >> Then we found a memleak situation in dlm_add_migration_mle(). >> When a mle found, it will be removed from dlm->hlist. If there is no >> pointer to it at that moment, the mle will become an ?orphan mle? >> that no process can find and release. >> >> Signed-off-by: Xuejiufei >> --- >> fs/ocfs2/dlm/dlmmaster.c | 11 ++++++++++- >> 1 files changed, 10 insertions(+), 1 deletions(-) >> >> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c >> index 005261c..20d2307 100644 >> --- a/fs/ocfs2/dlm/dlmmaster.c >> +++ b/fs/ocfs2/dlm/dlmmaster.c >> @@ -284,6 +284,7 @@ static void dlm_init_mle(struct dlm_master_list_entry *mle, >> mle->master = O2NM_MAX_NODES; >> mle->new_master = O2NM_MAX_NODES; >> mle->inuse = 0; >> + mle->assert_master = 0; >> >> BUG_ON(mle->type != DLM_MLE_BLOCK && >> mle->type != DLM_MLE_MASTER && >> @@ -1743,6 +1744,7 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data, >> u32 flags; >> int master_request = 0, have_lockres_ref = 0; >> int ret = 0; >> + int bit; >> >> if (!dlm_grab(dlm)) >> return 0; >> @@ -1770,7 +1772,11 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data, >> "MLE for it! (%.*s)\n", assert->node_idx, >> namelen, name); >> } else { > Looks good. > I am being really picky, looks there is no need to move bit variable to > be function level, i.e. > > int bit; > > spin_lock(&mle->spinlock); > mle->assert_master = 1; > spin_unlock(&mle->spinlock); > bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0); > > Thanks, > -Jeff >> - int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0); >> + spin_lock(&mle->spinlock); >> + mle->assert_master = 1; >> + spin_unlock(&mle->spinlock); >> + >> + bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0); >> if (bit >= O2NM_MAX_NODES) { >> /* not necessarily an error, though less likely. >> * could be master just re-asserting. */ >> @@ -3081,6 +3087,8 @@ static int dlm_add_migration_mle(struct dlm_ctxt *dlm, >> /* remove it so that only one mle will be found */ >> __dlm_unlink_mle(dlm, tmp); >> __dlm_mle_detach_hb_events(dlm, tmp); >> + if (tmp->type == DLM_MLE_BLOCK && tmp->assert_master == 0) >> + __dlm_put_mle(tmp); >> ret = DLM_MIGRATE_RESPONSE_MASTERY_REF; >> mlog(0, "%s:%.*s: master=%u, newmaster=%u, " >> "telling master to get ref for cleared out mle " >> @@ -3173,6 +3181,7 @@ static void dlm_clean_block_mle(struct dlm_ctxt *dlm, >> wake_up(&mle->wq); >> >> /* Do not need events any longer, so detach from heartbeat */ >> + __dlm_unlink_mle(dlm, mle); >> __dlm_mle_detach_hb_events(dlm, mle); >> __dlm_put_mle(mle); >> } >> > > . > Thank you for the suggestion and I really agree with you. Here is the patch after modification: Signed-off-by: Xuejiufei master = O2NM_MAX_NODES; mle->new_master = O2NM_MAX_NODES; mle->inuse = 0; + mle->assert_master = 0; BUG_ON(mle->type != DLM_MLE_BLOCK && mle->type != DLM_MLE_MASTER && @@ -1770,7 +1771,12 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data, "MLE for it! (%.*s)\n", assert->node_idx, namelen, name); } else { - int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0); + int bit; + spin_lock(&mle->spinlock); + mle->assert_master = 1; + spin_unlock(&mle->spinlock); + + bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0); if (bit >= O2NM_MAX_NODES) { /* not necessarily an error, though less likely. * could be master just re-asserting. */ @@ -3081,6 +3087,8 @@ static int dlm_add_migration_mle(struct dlm_ctxt *dlm, /* remove it so that only one mle will be found */ __dlm_unlink_mle(dlm, tmp); __dlm_mle_detach_hb_events(dlm, tmp); + if (tmp->type == DLM_MLE_BLOCK && tmp->assert_master == 0) + __dlm_put_mle(tmp); ret = DLM_MIGRATE_RESPONSE_MASTERY_REF; mlog(0, "%s:%.*s: master=%u, newmaster=%u, " "telling master to get ref for cleared out mle " @@ -3173,6 +3181,7 @@ static void dlm_clean_block_mle(struct dlm_ctxt *dlm, wake_up(&mle->wq); /* Do not need events any longer, so detach from heartbeat */ + __dlm_unlink_mle(dlm, mle); __dlm_mle_detach_hb_events(dlm, mle); __dlm_put_mle(mle); } -- 1.7.8.6