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author | Bart Van Assche <bvanassche@acm.org> | 2013-02-21 18:20:00 +0100 |
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committer | Roland Dreier <roland@purestorage.com> | 2013-02-25 18:31:14 +0100 |
commit | 2ce19e72f4d570c87e025ee6fca4eae699a8b712 (patch) | |
tree | f9055b2a0390954b222450ea93dffdab0316c674 /kernel | |
parent | IB/srp: Avoid endless SCSI error handling loop (diff) | |
download | linux-2ce19e72f4d570c87e025ee6fca4eae699a8b712.tar.xz linux-2ce19e72f4d570c87e025ee6fca4eae699a8b712.zip |
IB/srp: Fail I/O requests if the transport is offline
If an SRP target is no longer reachable and srp_reset_host() fails to
reconnect then ib_srp will invoke scsi_remove_host(). That function
will invoke __scsi_remove_device() for each LUN. And that last
function will change the device state from SDEV_TRANSPORT_OFFLINE into
SDEV_CANCEL. Certain user space software, e.g. older versions of
multipathd, continue queueing I/O to SCSI devices that are in the
SDEV_CANCEL state.
If these I/O requests are submitted as SG_IO that means that the
REQ_PREEMPT flag will be set and hence that these requests will be
passed to srp_queuecommand(). These requests will time out. If new
requests are queued fast enough from user space these active requests
will prevent __scsi_remove_device() to finish.
Avoid this by failing I/O requests in the SDEV_CANCEL state if the
transport is offline. Introduce a new variable to keep track of the
transport state instead of failing requests if (!target->connected ||
target->qp_in_error), so that the SCSI error handler has a chance to
retry commands after a transport layer failure occurred.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: <stable@vger.kernel.org> # 3.8
Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to '')
0 files changed, 0 insertions, 0 deletions