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authorBart Van Assche <bart.vanassche@sandisk.com>2016-09-26 12:58:49 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-10-28 03:45:22 -0400
commit9d57a641c4ece9965e022bd6be117202a06c5980 (patch)
tree41f0e0b67347ab7999e21a92b29f864046e2402d
parent14ec354717bc99689026ebaa848bff08e30e3443 (diff)
IB/srp: Fix infinite loop when FMR sg[0].offset != 0
commit 681cc3608355737c1effebc8145f95c8c3344bc3 upstream. 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@intel.com> Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/infiniband/ulp/srp/ib_srp.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 3322ed750172..6b07d4bca764 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1400,7 +1400,9 @@ 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;
@@ -1417,12 +1419,12 @@ 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;
}