From: David Stevens <stevensd@xxxxxxxxxxxx>
When continuing a short read/write, account for any completed bytes when
calculating the operation's target length. The operation's actual
accumulated length is fixed up by kiocb_done, and the target and actual
lengths are then compared by __io_complete_rw_common. That function
already propagated the actual length to userspace, but the incorrect
target length was causing it to always cancel linked operations, even
with a successfully completed read/write.
Fixes: 227c0c9673d8 ("io_uring: internally retry short reads")
Signed-off-by: David Stevens <stevensd@xxxxxxxxxxxx>
---
io_uring/rw.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 76ebcfebc9a6..aa9967a52dfd 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -706,13 +706,14 @@ int io_read(struct io_kiocb *req, unsigned int issue_flags)
struct kiocb *kiocb = &rw->kiocb;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
struct io_async_rw *io;
- ssize_t ret, ret2;
+ ssize_t ret, ret2, target_len;
loff_t *ppos;
if (!req_has_async_data(req)) {
ret = io_import_iovec(READ, req, &iovec, s, issue_flags);
if (unlikely(ret < 0))
return ret;
+ target_len = iov_iter_count(&s->iter);
} else {
io = req->async_data;
s = &io->s;
@@ -733,6 +734,7 @@ int io_read(struct io_kiocb *req, unsigned int issue_flags)
* need to make this conditional.
*/
iov_iter_restore(&s->iter, &s->iter_state);
+ target_len = iov_iter_count(&s->iter) + io->bytes_done;
iovec = NULL;
}
ret = io_rw_init_file(req, FMODE_READ);
@@ -740,7 +742,7 @@ int io_read(struct io_kiocb *req, unsigned int issue_flags)
kfree(iovec);
return ret;
}
- req->cqe.res = iov_iter_count(&s->iter);
+ req->cqe.res = target_len;
if (force_nonblock) {
/* If the file doesn't support async, just async punt */
@@ -850,18 +852,20 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags)
struct iovec *iovec;
struct kiocb *kiocb = &rw->kiocb;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
- ssize_t ret, ret2;
+ ssize_t ret, ret2, target_len;
loff_t *ppos;
if (!req_has_async_data(req)) {
ret = io_import_iovec(WRITE, req, &iovec, s, issue_flags);
if (unlikely(ret < 0))
return ret;
+ target_len = iov_iter_count(&s->iter);
} else {
struct io_async_rw *io = req->async_data;
s = &io->s;
iov_iter_restore(&s->iter, &s->iter_state);
+ target_len = iov_iter_count(&s->iter) + io->bytes_done;
iovec = NULL;
}
ret = io_rw_init_file(req, FMODE_WRITE);
@@ -869,7 +873,7 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags)
kfree(iovec);
return ret;
}
- req->cqe.res = iov_iter_count(&s->iter);
+ req->cqe.res = target_len;
if (force_nonblock) {
/* If the file doesn't support async, just async punt */
--
2.38.0.rc1.362.ged0d419d3c-goog
