Commit 4503b767 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: catch -EIO from buffered issue request failure 



-EIO bubbles up like -EAGAIN if we fail to allocate a request at the
lower level. Play it safe and treat it like -EAGAIN in terms of sync
retry, to avoid passing back an errant -EIO.

Catch some of these early for block based file, as non-mq devices
generally do not support NOWAIT. That saves us some overhead by
not first trying, then retrying from async context. We can go straight
to async punt instead.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ac8691c4

fs/io_uring.c

+23 −5
Original line number Diff line number Diff line
@@ -2088,6 +2088,15 @@ static struct file *__io_file_get(struct io_submit_state *state, int fd) 
	return state->file;

}



static bool io_bdev_nowait(struct block_device *bdev)

{

#ifdef CONFIG_BLOCK

	return !bdev || queue_is_mq(bdev_get_queue(bdev));

#else

	return true;

#endif

}



/*

 * If we tracked the file through the SCM inflight mechanism, we could support

 * any file. For now, just ensure that anything potentially problematic is done
@@ -2097,10 +2106,19 @@ static bool io_file_supports_async(struct file *file, int rw) 
{

	umode_t mode = file_inode(file)->i_mode;



	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISSOCK(mode))

	if (S_ISBLK(mode)) {

		if (io_bdev_nowait(file->f_inode->i_bdev))

			return true;

	if (S_ISREG(mode) && file->f_op != &io_uring_fops)

		return false;

	}

	if (S_ISCHR(mode) || S_ISSOCK(mode))

		return true;

	if (S_ISREG(mode)) {

		if (io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&

		    file->f_op != &io_uring_fops)

			return true;

		return false;

	}



	/* any ->read/write should understand O_NONBLOCK */

	if (file->f_flags & O_NONBLOCK)
@@ -2650,7 +2668,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock) 
	iov_count = iov_iter_count(&iter);

	ret = rw_verify_area(READ, req->file, &kiocb->ki_pos, iov_count);

	if (!ret) {

		ssize_t ret2;

		ssize_t ret2 = 0;



		if (req->file->f_op->read_iter)

			ret2 = call_read_iter(req->file, kiocb, &iter);
@@ -2658,7 +2676,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock) 
			ret2 = loop_rw_iter(READ, req->file, kiocb, &iter);



		/* Catch -EAGAIN return for forced non-blocking submission */

		if (!force_nonblock || ret2 != -EAGAIN) {

		if (!force_nonblock || (ret2 != -EAGAIN && ret2 != -EIO)) {

			kiocb_done(kiocb, ret2);

		} else {

copy_iov:

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