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| author | Mike Christie <michaelc@cs.wisc.edu> | 2012-01-26 21:13:11 -0600 |
|---|---|---|
| committer | James Bottomley <JBottomley@Parallels.com> | 2012-02-19 08:09:00 -0600 |
| commit | e3d338a536330b5ffc9f28d7c6a4cdf6ba51867a (patch) | |
| tree | 6c49d84c7ac6e73ab2b3fbfbceaedcdcb2529f72 | |
| parent | 1304be5fe0efb42b7ec6a50dd8e1a9bce2adae17 (diff) | |
| download | op-kernel-dev-e3d338a536330b5ffc9f28d7c6a4cdf6ba51867a.zip op-kernel-dev-e3d338a536330b5ffc9f28d7c6a4cdf6ba51867a.tar.gz | |
[SCSI] libiscsi: fix cmd timeout/completion race
If the driver/lib has called scsi_done and cleaned up internally but
scsi layer has not yet called blk_mark_rq_complete when the command
times out we hit a problem if the timeout code calls blk_mark_rq_complete first.
When the time out code calls into the driver we were returning
BLK_EH_RESET_TIMER and that causes the timeout code to just call
us again later.
We need to be calling BLK_EH_HANDLED so the timeout code can complete
the completion process because it had called blk_mark_rq_complete
on the command and now owns its processing.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
| -rw-r--r-- | drivers/scsi/libiscsi.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 8582d7c2..82c3fd4 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -1909,6 +1909,16 @@ static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc) ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc); spin_lock(&session->lock); + task = (struct iscsi_task *)sc->SCp.ptr; + if (!task) { + /* + * Raced with completion. Blk layer has taken ownership + * so let timeout code complete it now. + */ + rc = BLK_EH_HANDLED; + goto done; + } + if (session->state != ISCSI_STATE_LOGGED_IN) { /* * We are probably in the middle of iscsi recovery so let @@ -1925,16 +1935,6 @@ static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc) goto done; } - task = (struct iscsi_task *)sc->SCp.ptr; - if (!task) { - /* - * Raced with completion. Just reset timer, and let it - * complete normally - */ - rc = BLK_EH_RESET_TIMER; - goto done; - } - /* * If we have sent (at least queued to the network layer) a pdu or * recvd one for the task since the last timeout ask for |
