From: David Jeffery djeffery@redhat.com
[ Upstream commit 733ab7e1b5d1041204c4ca7373f6e6f9d08e3283 ]
When aborting a SCSI command through fnic, there is a race with the fnic interrupt handler which can result in the SCSI command and its request being completed twice. If the interrupt handler claims the command by setting CMD_SP to NULL first, the abort handler assumes the interrupt handler has completed the command and returns SUCCESS, causing the request for the scsi_cmnd to be re-queued.
But the interrupt handler may not have finished the command yet. After it drops the spinlock protecting CMD_SP, it does memory cleanup before finally calling scsi_done() to complete the scsi_cmnd. If the call to scsi_done occurs after the abort handler finishes and re-queues the request, the completion of the scsi_cmnd will advance and try to double complete a request already queued for retry.
This patch fixes the issue by moving scsi_done() and any other use of scsi_cmnd to before the spinlock is released by the interrupt handler.
Link: https://lore.kernel.org/r/20220311184359.2345319-1-djeffery@redhat.com Reviewed-by: Laurence Oberman loberman@redhat.com Reviewed-by: Ming Lei ming.lei@redhat.com Signed-off-by: David Jeffery djeffery@redhat.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/fnic/fnic_scsi.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c index 88c549f257db..40a52feb315d 100644 --- a/drivers/scsi/fnic/fnic_scsi.c +++ b/drivers/scsi/fnic/fnic_scsi.c @@ -986,8 +986,6 @@ static void fnic_fcpio_icmnd_cmpl_handler(struct fnic *fnic, CMD_SP(sc) = NULL; CMD_FLAGS(sc) |= FNIC_IO_DONE;
- spin_unlock_irqrestore(io_lock, flags); - if (hdr_status != FCPIO_SUCCESS) { atomic64_inc(&fnic_stats->io_stats.io_failures); shost_printk(KERN_ERR, fnic->lport->host, "hdr status = %s\n", @@ -996,8 +994,6 @@ static void fnic_fcpio_icmnd_cmpl_handler(struct fnic *fnic,
fnic_release_ioreq_buf(fnic, io_req, sc);
- mempool_free(io_req, fnic->io_req_pool); - cmd_trace = ((u64)hdr_status << 56) | (u64)icmnd_cmpl->scsi_status << 48 | (u64)icmnd_cmpl->flags << 40 | (u64)sc->cmnd[0] << 32 | @@ -1021,6 +1017,12 @@ static void fnic_fcpio_icmnd_cmpl_handler(struct fnic *fnic, } else fnic->lport->host_stats.fcp_control_requests++;
+ /* Call SCSI completion function to complete the IO */ + scsi_done(sc); + spin_unlock_irqrestore(io_lock, flags); + + mempool_free(io_req, fnic->io_req_pool); + atomic64_dec(&fnic_stats->io_stats.active_ios); if (atomic64_read(&fnic->io_cmpl_skip)) atomic64_dec(&fnic->io_cmpl_skip); @@ -1049,9 +1051,6 @@ static void fnic_fcpio_icmnd_cmpl_handler(struct fnic *fnic, if(io_duration_time > atomic64_read(&fnic_stats->io_stats.current_max_io_time)) atomic64_set(&fnic_stats->io_stats.current_max_io_time, io_duration_time); } - - /* Call SCSI completion function to complete the IO */ - scsi_done(sc); }
/* fnic_fcpio_itmf_cmpl_handler