From: Hou Tao <hout...@huawei.com>
When invoking virtio_fs_enqueue_req() through kworker, both the
allocation of the sg array and the bounce buffer still use GFP_ATOMIC.
Considering the size of the sg array may be greater than PAGE_SIZE, use
GFP_NOFS instead of GFP_ATOMIC to lower the possibility of memory
allocation failure and to avoid unnecessarily depleting the atomic
reserves. GFP_NOFS is not passed to virtio_fs_enqueue_req() directly,
use GFP_KERNEL and memalloc_nofs_{save|restore} helpers instead.
Signed-off-by: Hou Tao <hout...@huawei.com>
---
fs/fuse/virtio_fs.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 34b9370beba6d..9ee71051c89f2 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -108,7 +108,8 @@ struct virtio_fs_argbuf {
};
static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq,
- struct fuse_req *req, bool in_flight);
+ struct fuse_req *req, bool in_flight,
+ gfp_t gfp);
static const struct constant_table dax_param_enums[] = {
{"always", FUSE_DAX_ALWAYS },
@@ -394,6 +395,8 @@ static void virtio_fs_request_dispatch_work(struct
work_struct *work)
/* Dispatch pending requests */
while (1) {
+ unsigned int flags;
+
spin_lock(&fsvq->lock);
req = list_first_entry_or_null(&fsvq->queued_reqs,
struct fuse_req, list);
@@ -404,7 +407,9 @@ static void virtio_fs_request_dispatch_work(struct
work_struct *work)
list_del_init(&req->list);
spin_unlock(&fsvq->lock);
- ret = virtio_fs_enqueue_req(fsvq, req, true);
+ flags = memalloc_nofs_save();
+ ret = virtio_fs_enqueue_req(fsvq, req, true, GFP_KERNEL);
+ memalloc_nofs_restore(flags);
if (ret < 0) {
if (ret == -ENOMEM || ret == -ENOSPC) {
spin_lock(&fsvq->lock);
@@ -1332,7 +1337,8 @@ static bool use_scattered_argbuf(struct fuse_req *req)
/* Add a request to a virtqueue and kick the device */
static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq,
- struct fuse_req *req, bool in_flight)
+ struct fuse_req *req, bool in_flight,
+ gfp_t gfp)
{
/* requests need at least 4 elements */
struct scatterlist *stack_sgs[6];
@@ -1364,8 +1370,8 @@ static int virtio_fs_enqueue_req(struct virtio_fs_vq
*fsvq,
total_sgs = sg_count_fuse_req(req, in_args_len, out_args_len,
flat_argbuf);
if (total_sgs > ARRAY_SIZE(stack_sgs)) {
- sgs = kmalloc_array(total_sgs, sizeof(sgs[0]), GFP_ATOMIC);
- sg = kmalloc_array(total_sgs, sizeof(sg[0]), GFP_ATOMIC);
+ sgs = kmalloc_array(total_sgs, sizeof(sgs[0]), gfp);
+ sg = kmalloc_array(total_sgs, sizeof(sg[0]), gfp);
if (!sgs || !sg) {
ret = -ENOMEM;
goto out;
@@ -1373,8 +1379,8 @@ static int virtio_fs_enqueue_req(struct virtio_fs_vq
*fsvq,
}
/* Use a bounce buffer since stack args cannot be mapped */
- req->argbuf = virtio_fs_argbuf_new(in_args_len, out_args_len,
- GFP_ATOMIC, flat_argbuf);
+ req->argbuf = virtio_fs_argbuf_new(in_args_len, out_args_len, gfp,
+ flat_argbuf);
if (!req->argbuf) {
ret = -ENOMEM;
goto out;
@@ -1473,7 +1479,7 @@ __releases(fiq->lock)
fuse_len_args(req->args->out_numargs, req->args->out_args));
fsvq = &fs->vqs[queue_id];
- ret = virtio_fs_enqueue_req(fsvq, req, false);
+ ret = virtio_fs_enqueue_req(fsvq, req, false, GFP_ATOMIC);
if (ret < 0) {
if (ret == -ENOMEM || ret == -ENOSPC) {
/*
--
2.29.2
