Avoid that mapping an sg-list in which the first element has a
non-zero offset triggers an infinite loop when using FMR. This
patch makes the FMR mapping code similar to that of ib_sg_to_pages().
Note: older Mellanox HCAs do not support non-zero offsets for FMR.
See also commit 8c4037b501ac ("IB/srp: always avoid non-zero offsets
into an FMR").
Reported-by: Alex Estrin <alex.estrin@xxxxxxxxx>
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
drivers/infiniband/ulp/srp/ib_srp.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 06bb7a905635..29ec5e2f247e 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1416,7 +1416,9 @@ static int srp_map_sg_entry(struct srp_map_state *state,
while (dma_len) {
unsigned offset = dma_addr & ~dev->mr_page_mask;
- if (state->npages == dev->max_pages_per_mr || offset != 0) {
+
+ if (state->npages == dev->max_pages_per_mr ||
+ (state->npages > 0 && offset != 0)) {
ret = srp_map_finish_fmr(state, ch);
if (ret)
return ret;
@@ -1433,12 +1435,12 @@ static int srp_map_sg_entry(struct srp_map_state *state,
}
/*
- * If the last entry of the MR wasn't a full page, then we need to
+ * If the end of the MR is not on a page boundary then we need to
* close it out and start a new one -- we can only merge at page
* boundaries.
*/
ret = 0;
- if (len != dev->mr_page_size)
+ if ((dma_addr & ~dev->mr_page_mask) != 0)
ret = srp_map_finish_fmr(state, ch);
return ret;
}
--
2.10.0
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