[PATCH v2 03/21] libiscsi: Make use of new the sg_map helper function

Logan Gunthorpe
2017-04-25T18:20:50Z

Convert the kmap and kmap_atomic uses to the sg_map function. We now
store the flags for the kmap instead of a boolean to indicate
atomicitiy. We use ISCSI_TCP_INTERNAL_ERR error type that was prepared
earlier for this.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Lee Duncan <lduncan@suse.com>
Cc: Chris Leech <cleech@redhat.com>
---
drivers/scsi/libiscsi_tcp.c | 32 ++++++++++++++++++++------------
include/scsi/libiscsi_tcp.h | 2 +-
2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index 63a1d69..a34e25c 100644
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -133,25 +133,23 @@ static void iscsi_tcp_segment_map(struct iscsi_segment *segment, int recv)
if (page_count(sg_page(sg)) >= 1 && !recv)
return;

- if (recv) {
- segment->atomic_mapped = true;
- segment->sg_mapped = kmap_atomic(sg_page(sg));
- } else {
- segment->atomic_mapped = false;
- /* the xmit path can sleep with the page mapped so use kmap */
- segment->sg_mapped = kmap(sg_page(sg));
+ /* the xmit path can sleep with the page mapped so don't use atomic */
+ segment->sg_map_flags = recv ? SG_KMAP_ATOMIC : SG_KMAP;
+ segment->sg_mapped = sg_map(sg, 0, segment->sg_map_flags);
+
+ if (IS_ERR(segment->sg_mapped)) {
+ segment->sg_mapped = NULL;
+ return;
}

- segment->data = segment->sg_mapped + sg->offset + segment->sg_offset;
+ segment->data = segment->sg_mapped + segment->sg_offset;
}

void iscsi_tcp_segment_unmap(struct iscsi_segment *segment)
{
if (segment->sg_mapped) {
- if (segment->atomic_mapped)
- kunmap_atomic(segment->sg_mapped);
- else
- kunmap(sg_page(segment->sg));
+ sg_unmap(segment->sg, segment->sg_mapped, 0,
+ segment->sg_map_flags);
segment->sg_mapped = NULL;
segment->data = NULL;
}
@@ -304,6 +302,9 @@ iscsi_tcp_segment_recv(struct iscsi_tcp_conn *tcp_conn,
break;
}

+ if (segment->data)
+ return -EFAULT;
+
copy = min(len - copied, segment->size - segment->copied);
ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "copying %d\n", copy);
memcpy(segment->data + segment->copied, ptr + copied, copy);
@@ -927,6 +928,13 @@ int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
avail);
rc = iscsi_tcp_segment_recv(tcp_conn, segment, ptr, avail);
BUG_ON(rc == 0);
+ if (rc < 0) {
+ ISCSI_DBG_TCP(conn, "memory fault. Consumed %d\n",
+ consumed);
+ *status = ISCSI_TCP_INTERNAL_ERR;
+ goto skb_done;
+ }
+
consumed += rc;

if (segment->total_copied >= segment->total_size) {
diff --git a/include/scsi/libiscsi_tcp.h b/include/scsi/libiscsi_tcp.h
index 90691ad..58c79af 100644
--- a/include/scsi/libiscsi_tcp.h
+++ b/include/scsi/libiscsi_tcp.h
@@ -47,7 +47,7 @@ struct iscsi_segment {
struct scatterlist *sg;
void *sg_mapped;
unsigned int sg_offset;
- bool atomic_mapped;
+ int sg_map_flags;

iscsi_segment_done_fn_t *done;
};
--
2.1.4

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