Call io_async_list_note at the end if -EAGAIN is going to be returned;
we need iov_count for that, which we have (almost) at the same time as
we need to free iovec.
Instead of using a second return value reset the normal one after
passing it to io_rw_done.
Unless rw_verify_area returns -EAGAIN this shouldn't result in different
behavior.
This change should make it easier to punt a request to the workers by
returning -EAGAIN and still calling io_async_list_note if needed.
Signed-off-by: Stefan Bühler <source@xxxxxxxxxxxx>
---
fs/io_uring.c | 89 ++++++++++++++++++++++-----------------------------
1 file changed, 39 insertions(+), 50 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 84efb8956734..52e435a72b6f 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1062,26 +1062,24 @@ static int io_read(struct io_kiocb *req, const struct sqe_submit *s,
ret = io_import_iovec(req->ctx, READ, s, &iovec, &iter);
if (ret)
return ret;
-
iov_count = iov_iter_count(&iter);
+
ret = rw_verify_area(READ, file, &kiocb->ki_pos, iov_count);
- if (!ret) {
- ssize_t ret2;
+ if (ret)
+ goto out_free;
- /* Catch -EAGAIN return for forced non-blocking submission */
- ret2 = call_read_iter(file, kiocb, &iter);
- if (!force_nonblock || ret2 != -EAGAIN) {
- io_rw_done(kiocb, ret2);
- } else {
- /*
- * If ->needs_lock is true, we're already in async
- * context.
- */
- if (!s->needs_lock)
- io_async_list_note(READ, req, iov_count);
- ret = -EAGAIN;
- }
+ /* Passthrough -EAGAIN return for forced non-blocking submission */
+ ret = call_read_iter(file, kiocb, &iter);
+ if (!(force_nonblock && ret == -EAGAIN)) {
+ io_rw_done(kiocb, ret);
+ ret = 0;
}
+
+out_free:
+ /* If ->needs_lock is true, we're already in async context. */
+ if (ret == -EAGAIN && !s->needs_lock)
+ io_async_list_note(READ, req, iov_count);
+
kfree(iovec);
return ret;
}
@@ -1109,50 +1107,41 @@ static int io_write(struct io_kiocb *req, const struct sqe_submit *s,
ret = io_import_iovec(req->ctx, WRITE, s, &iovec, &iter);
if (ret)
return ret;
-
iov_count = iov_iter_count(&iter);
ret = -EAGAIN;
- if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT)) {
- /* If ->needs_lock is true, we're already in async context. */
- if (!s->needs_lock)
- io_async_list_note(WRITE, req, iov_count);
+ if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT))
goto out_free;
- }
ret = rw_verify_area(WRITE, file, &kiocb->ki_pos, iov_count);
- if (!ret) {
- ssize_t ret2;
+ if (ret)
+ goto out_free;
- /*
- * Open-code file_start_write here to grab freeze protection,
- * which will be released by another thread in
- * io_complete_rw(). Fool lockdep by telling it the lock got
- * released so that it doesn't complain about the held lock when
- * we return to userspace.
- */
- if (S_ISREG(file_inode(file)->i_mode)) {
- __sb_start_write(file_inode(file)->i_sb,
- SB_FREEZE_WRITE, true);
- __sb_writers_release(file_inode(file)->i_sb,
- SB_FREEZE_WRITE);
- }
- kiocb->ki_flags |= IOCB_WRITE;
+ /*
+ * Open-code file_start_write here to grab freeze protection,
+ * which will be released by another thread in
+ * io_complete_rw(). Fool lockdep by telling it the lock got
+ * released so that it doesn't complain about the held lock when
+ * we return to userspace.
+ */
+ if (S_ISREG(file_inode(file)->i_mode)) {
+ __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
+ __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
+ }
+ kiocb->ki_flags |= IOCB_WRITE;
- ret2 = call_write_iter(file, kiocb, &iter);
- if (!force_nonblock || ret2 != -EAGAIN) {
- io_rw_done(kiocb, ret2);
- } else {
- /*
- * If ->needs_lock is true, we're already in async
- * context.
- */
- if (!s->needs_lock)
- io_async_list_note(WRITE, req, iov_count);
- ret = -EAGAIN;
- }
+ /* Passthrough -EAGAIN return for forced non-blocking submission */
+ ret = call_write_iter(file, kiocb, &iter);
+ if (!(force_nonblock && ret == -EAGAIN)) {
+ io_rw_done(kiocb, ret);
+ ret = 0;
}
+
out_free:
+ /* If ->needs_lock is true, we're already in async context. */
+ if (ret == -EAGAIN && !s->needs_lock)
+ io_async_list_note(WRITE, req, iov_count);
+
kfree(iovec);
return ret;
}
--
2.20.1
