From 57ef4e510939e305ad905cc54b8031401ff5450e Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 18 Jun 2019 09:37:55 +0800 Subject: [PATCH] scsi: ppa: use sg helper to iterate over scatterlist Unlike the legacy I/O path, scsi-mq preallocates a large array to hold the scatterlist for each request. This static allocation can consume substantial amounts of memory on modern controllers which support a large number of concurrently outstanding requests. To facilitate a switch to a smaller static allocation combined with a dynamic allocation for requests that need it, we need to make sure all SCSI drivers handle chained scatterlists correctly. Convert remaining drivers that directly dereference the scatterlist array to using the iterator functions. [mkp: clarified commit message] Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen --- drivers/scsi/ppa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/ppa.c b/drivers/scsi/ppa.c index 35213082e933..a406cc825426 100644 --- a/drivers/scsi/ppa.c +++ b/drivers/scsi/ppa.c @@ -590,7 +590,7 @@ static int ppa_completion(struct scsi_cmnd *cmd) if (cmd->SCp.buffer && !cmd->SCp.this_residual) { /* if scatter/gather, advance to the next segment */ if (cmd->SCp.buffers_residual--) { - cmd->SCp.buffer++; + cmd->SCp.buffer = sg_next(cmd->SCp.buffer); cmd->SCp.this_residual = cmd->SCp.buffer->length; cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);