This adds support to existing fuse copy code to copy
from/to the ring buffer. The ring buffer is here mmaped
shared between kernel and userspace.
This also fuse_ prefixes the copy_out_args function
Signed-off-by: Bernd Schubert <bschubert@xxxxxxx>
---
fs/fuse/dev.c | 60 ++++++++++++++++++++++++++++++----------------------
fs/fuse/fuse_dev_i.h | 38 +++++++++++++++++++++++++++++++++
2 files changed, 73 insertions(+), 25 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 05a87731b5c3..a7d26440de39 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -637,21 +637,7 @@ static int unlock_request(struct fuse_req *req)
return err;
}
-struct fuse_copy_state {
- int write;
- struct fuse_req *req;
- struct iov_iter *iter;
- struct pipe_buffer *pipebufs;
- struct pipe_buffer *currbuf;
- struct pipe_inode_info *pipe;
- unsigned long nr_segs;
- struct page *pg;
- unsigned len;
- unsigned offset;
- unsigned move_pages:1;
-};
-
-static void fuse_copy_init(struct fuse_copy_state *cs, int write,
+void fuse_copy_init(struct fuse_copy_state *cs, int write,
struct iov_iter *iter)
{
memset(cs, 0, sizeof(*cs));
@@ -662,6 +648,7 @@ static void fuse_copy_init(struct fuse_copy_state *cs, int write,
/* Unmap and put previous page of userspace buffer */
static void fuse_copy_finish(struct fuse_copy_state *cs)
{
+
if (cs->currbuf) {
struct pipe_buffer *buf = cs->currbuf;
@@ -726,6 +713,10 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
cs->pipebufs++;
cs->nr_segs++;
}
+ } else if (cs->is_uring) {
+ if (cs->ring.offset > cs->ring.buf_sz)
+ return -ERANGE;
+ cs->len = cs->ring.buf_sz - cs->ring.offset;
} else {
size_t off;
err = iov_iter_get_pages2(cs->iter, &page, PAGE_SIZE, 1, &off);
@@ -744,21 +735,35 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
{
unsigned ncpy = min(*size, cs->len);
+
if (val) {
- void *pgaddr = kmap_local_page(cs->pg);
- void *buf = pgaddr + cs->offset;
+
+ void *pgaddr = NULL;
+ void *buf;
+
+ if (cs->is_uring) {
+ buf = cs->ring.buf + cs->ring.offset;
+ cs->ring.offset += ncpy;
+
+ } else {
+ pgaddr = kmap_local_page(cs->pg);
+ buf = pgaddr + cs->offset;
+ }
if (cs->write)
memcpy(buf, *val, ncpy);
else
memcpy(*val, buf, ncpy);
- kunmap_local(pgaddr);
+ if (pgaddr)
+ kunmap_local(pgaddr);
+
*val += ncpy;
}
*size -= ncpy;
cs->len -= ncpy;
cs->offset += ncpy;
+
return ncpy;
}
@@ -1006,9 +1011,9 @@ static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
}
/* Copy request arguments to/from userspace buffer */
-static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
- unsigned argpages, struct fuse_arg *args,
- int zeroing)
+int fuse_copy_args(struct fuse_copy_state *cs, unsigned int numargs,
+ unsigned int argpages, struct fuse_arg *args,
+ int zeroing)
{
int err = 0;
unsigned i;
@@ -1873,10 +1878,15 @@ static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
return NULL;
}
-static int copy_out_args(struct fuse_copy_state *cs, struct fuse_args *args,
- unsigned nbytes)
+int fuse_copy_out_args(struct fuse_copy_state *cs, struct fuse_args *args,
+ unsigned int nbytes)
{
- unsigned reqsize = sizeof(struct fuse_out_header);
+
+ unsigned int reqsize = 0;
+
+ /* Uring has the out header outside of args */
+ if (!cs->is_uring)
+ reqsize = sizeof(struct fuse_out_header);
reqsize += fuse_len_args(args->out_numargs, args->out_args);
@@ -1976,7 +1986,7 @@ static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
if (oh.error)
err = nbytes != sizeof(oh) ? -EINVAL : 0;
else
- err = copy_out_args(cs, req->args, nbytes);
+ err = fuse_copy_out_args(cs, req->args, nbytes);
fuse_copy_finish(cs);
spin_lock(&fpq->lock);
diff --git a/fs/fuse/fuse_dev_i.h b/fs/fuse/fuse_dev_i.h
index e6289bafb788..f3e69ab4c2be 100644
--- a/fs/fuse/fuse_dev_i.h
+++ b/fs/fuse/fuse_dev_i.h
@@ -13,6 +13,36 @@
#define FUSE_INT_REQ_BIT (1ULL << 0)
#define FUSE_REQ_ID_STEP (1ULL << 1)
+struct fuse_arg;
+struct fuse_args;
+
+struct fuse_copy_state {
+ int write;
+ struct fuse_req *req;
+ struct iov_iter *iter;
+ struct pipe_buffer *pipebufs;
+ struct pipe_buffer *currbuf;
+ struct pipe_inode_info *pipe;
+ unsigned long nr_segs;
+ struct page *pg;
+ unsigned int len;
+ unsigned int offset;
+ unsigned int move_pages:1, is_uring:1;
+ struct {
+ /* pointer into the ring buffer */
+ char *buf;
+
+ /* for copy to the ring request buffer, the buffer size - must
+ * not be exceeded, for copy from the ring request buffer,
+ * the size filled in by user space
+ */
+ unsigned int buf_sz;
+
+ /* offset within buf while it is copying from/to the buf */
+ unsigned int offset;
+ } ring;
+};
+
static inline struct fuse_dev *fuse_get_dev(struct file *file)
{
/*
@@ -24,6 +54,14 @@ static inline struct fuse_dev *fuse_get_dev(struct file *file)
void fuse_dev_end_requests(struct list_head *head);
+void fuse_copy_init(struct fuse_copy_state *cs, int write,
+ struct iov_iter *iter);
+int fuse_copy_args(struct fuse_copy_state *cs, unsigned int numargs,
+ unsigned int argpages, struct fuse_arg *args,
+ int zeroing);
+int fuse_copy_out_args(struct fuse_copy_state *cs, struct fuse_args *args,
+ unsigned int nbytes);
+
#endif
--
2.40.1
