[PATCH AUTOSEL 6.6 160/294] vhost-scsi: Return queue full for page alloc failures during copy

Sasha Levin
2025-05-05T23:01:56Z

From: Mike Christie <michael.christie@oracle.com>

[ Upstream commit 891b99eab0f89dbe08d216f4ab71acbeaf7a3102 ]

This has us return queue full if we can't allocate a page during the
copy operation so the initiator can retry.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20241203191705.19431-5-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/vhost/scsi.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 8d8a22504d71f..9a62372bdac32 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -746,7 +746,7 @@ vhost_scsi_copy_iov_to_sgl(struct vhost_scsi_cmd *cmd, struct iov_iter *iter,
size_t len = iov_iter_count(iter);
unsigned int nbytes = 0;
struct page *page;
- int i;
+ int i, ret;

if (cmd->tvc_data_direction == DMA_FROM_DEVICE) {
cmd->saved_iter_addr = dup_iter(&cmd->saved_iter, iter,
@@ -759,6 +759,7 @@ vhost_scsi_copy_iov_to_sgl(struct vhost_scsi_cmd *cmd, struct iov_iter *iter,
page = alloc_page(GFP_KERNEL);
if (!page) {
i--;
+ ret = -ENOMEM;
goto err;
}

@@ -766,8 +767,10 @@ vhost_scsi_copy_iov_to_sgl(struct vhost_scsi_cmd *cmd, struct iov_iter *iter,
sg_set_page(&sg[i], page, nbytes, 0);

if (cmd->tvc_data_direction == DMA_TO_DEVICE &&
- copy_page_from_iter(page, 0, nbytes, iter) != nbytes)
+ copy_page_from_iter(page, 0, nbytes, iter) != nbytes) {
+ ret = -EFAULT;
goto err;
+ }

len -= nbytes;
}
@@ -782,7 +785,7 @@ vhost_scsi_copy_iov_to_sgl(struct vhost_scsi_cmd *cmd, struct iov_iter *iter,
for (; i >= 0; i--)
__free_page(sg_page(&sg[i]));
kfree(cmd->saved_iter_addr);
- return -ENOMEM;
+ return ret;
}

static int
@@ -1221,9 +1224,9 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
" %d\n", cmd, exp_data_len, prot_bytes, data_direction);

if (data_direction != DMA_NONE) {
- if (unlikely(vhost_scsi_mapal(cmd, prot_bytes,
- &prot_iter, exp_data_len,
- &data_iter))) {
+ ret = vhost_scsi_mapal(cmd, prot_bytes, &prot_iter,
+ exp_data_len, &data_iter);
+ if (unlikely(ret)) {
vq_err(vq, "Failed to map iov to sgl\n");
vhost_scsi_release_cmd_res(&cmd->tvc_se_cmd);
goto err;
--
2.39.5