Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | green@linuxhac ... | Subject | [PATCH 3/4] staging/lustre/llite: avoid nonatomic memory alloc under spinlock | Date | Sat, 7 Mar 2015 19:24:28 -0500 |
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From: Lai Siyao <lai.siyao@intel.com>
ll_intent_drop_lock() may sleep in memory allocation, which should not be called inside spinlock.
Signed-off-by: Lai Siyao <lai.siyao@intel.com> Signed-off-by: Jian Yu <jian.yu@intel.com> Reviewed-on: http://review.whamcloud.com/10674 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2272 Signed-off-by: Oleg Drokin <oleg.drokin@intel.com> --- drivers/staging/lustre/lustre/llite/statahead.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/lustre/lustre/llite/statahead.c b/drivers/staging/lustre/lustre/llite/statahead.c index fe732fa..b75562c 100644 --- a/drivers/staging/lustre/lustre/llite/statahead.c +++ b/drivers/staging/lustre/lustre/llite/statahead.c @@ -706,11 +706,21 @@ static int ll_statahead_interpret(struct ptlrpc_request *req, struct ll_inode_info *lli = ll_i2info(dir); struct ll_statahead_info *sai = NULL; struct ll_sa_entry *entry; + __u64 handle = 0; int wakeup; if (it_disposition(it, DISP_LOOKUP_NEG)) rc = -ENOENT; + if (rc == 0) { + /* release ibits lock ASAP to avoid deadlock when statahead + * thread enqueues lock on parent in readdir and another + * process enqueues lock on child with parent lock held, eg. + * unlink. */ + handle = it->d.lustre.it_lock_handle; + ll_intent_drop_lock(it); + } + spin_lock(&lli->lli_sa_lock); /* stale entry */ if (unlikely(lli->lli_sai == NULL || @@ -745,8 +755,7 @@ static int ll_statahead_interpret(struct ptlrpc_request *req, * when statahead thread tries to enqueue lock on parent * for readpage and other tries to enqueue lock on child * with parent's lock held, for example: unlink. */ - entry->se_handle = it->d.lustre.it_lock_handle; - ll_intent_drop_lock(it); + entry->se_handle = handle; wakeup = sa_received_empty(sai); list_add_tail(&entry->se_list, &sai->sai_entries_received); -- 2.1.0
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