Commit 0c97c437 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: twf: convert bch2_stdio_redirect_readline() to darray 



We now read the line from the buffer atomically, which means we have to
allow the buffer to grow past STDIO_REDIRECT_BUFSIZE if we're waiting
for a full line - this behaviour is necessary for
stdio_redirect_readline_timeout() in the next patch.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 36008d5d

fs/bcachefs/error.c

+9 −6
Original line number Diff line number Diff line
@@ -109,18 +109,21 @@ static enum ask_yn bch2_fsck_ask_yn(struct bch_fs *c) 
	if (!stdio)

		return YN_NO;



	char buf[100];

	darray_char line = {};

	int ret;



	do {

		bch2_print(c, " (y,n, or Y,N for all errors of this type) ");



		int r = bch2_stdio_redirect_readline(stdio, buf, sizeof(buf) - 1);

		if (r < 0)

			return YN_NO;

		buf[r] = '\0';

	} while ((ret = parse_yn_response(buf)) < 0);

		int r = bch2_stdio_redirect_readline(stdio, &line);

		if (r < 0) {

			ret = YN_NO;

			break;

		}

		darray_last(line) = '\0';

	} while ((ret = parse_yn_response(line.data)) < 0);



	darray_exit(&line);

	return ret;

}

#else

fs/bcachefs/thread_with_file.c

+42 −28
Original line number Diff line number Diff line
@@ -67,9 +67,14 @@ int bch2_run_thread_with_file(struct thread_with_file *thr, 


/* stdio_redirect */



static bool stdio_redirect_has_more_input(struct stdio_redirect *stdio, size_t seen)

{

	return stdio->input.buf.nr > seen || stdio->done;

}



static bool stdio_redirect_has_input(struct stdio_redirect *stdio)

{

	return stdio->input.buf.nr || stdio->done;

	return stdio_redirect_has_more_input(stdio, 0);

}



static bool stdio_redirect_has_output(struct stdio_redirect *stdio)
@@ -181,9 +186,13 @@ static ssize_t thread_with_stdio_write(struct file *file, const char __user *ubu 
		}



		spin_lock(&buf->lock);

		if (buf->buf.nr < STDIO_REDIRECT_BUFSIZE)

			darray_make_room_gfp(&buf->buf,

				min(b, STDIO_REDIRECT_BUFSIZE - buf->buf.nr), GFP_NOWAIT);

		size_t makeroom = b;

		if (!buf->waiting_for_line || memchr(buf->buf.data, '\n', buf->buf.nr))

			makeroom = min_t(ssize_t, makeroom,

				   max_t(ssize_t, STDIO_REDIRECT_BUFSIZE - buf->buf.nr,

						  0));

		darray_make_room_gfp(&buf->buf, makeroom, GFP_NOWAIT);



		b = min(len, darray_room(buf->buf));



		if (b && !copy_from_user_nofault(&darray_top(buf->buf), ubuf, b)) {
@@ -355,43 +364,48 @@ int bch2_stdio_redirect_read(struct stdio_redirect *stdio, char *ubuf, size_t le 
	return ret;

}



int bch2_stdio_redirect_readline(struct stdio_redirect *stdio, char *ubuf, size_t len)

int bch2_stdio_redirect_readline(struct stdio_redirect *stdio, darray_char *line)

{

	struct stdio_buf *buf = &stdio->input;

	size_t copied = 0;

	ssize_t ret = 0;

	size_t seen = 0;

again:

	do {

		wait_event_timeout(buf->wait, stdio_redirect_has_input(stdio),

	wait_event_timeout(buf->wait, stdio_redirect_has_more_input(stdio, seen),

			   sysctl_hung_task_timeout_secs * HZ / 2);

	} while (!stdio_redirect_has_input(stdio));



	if (stdio->done) {

		ret = -1;

		goto out;

	}

	if (stdio->done)

		return -1;



	spin_lock(&buf->lock);

	size_t b = min(len, buf->buf.nr);

	char *n = memchr(buf->buf.data, '\n', b);

	if (n)

		b = min_t(size_t, b, n + 1 - buf->buf.data);

	seen = buf->buf.nr;

	char *n = memchr(buf->buf.data, '\n', seen);

	if (!n) {

		buf->waiting_for_line = true;

		spin_unlock(&buf->lock);

		goto again;

	}



	size_t b = n + 1 - buf->buf.data;

	if (b > line->size) {

		spin_unlock(&buf->lock);

		int ret = darray_resize(line, b);

		if (ret)

			return ret;

		seen = 0;

		goto again;

	}



	buf->buf.nr -= b;

	memcpy(ubuf, buf->buf.data, b);

	memcpy(line->data, buf->buf.data, b);

	memmove(buf->buf.data,

		buf->buf.data + b,

		buf->buf.nr);

	ubuf += b;

	len -= b;

	copied += b;

	line->nr = b;



	buf->waiting_for_line = false;

	spin_unlock(&buf->lock);



	wake_up(&buf->wait);



	if (!n && len)

		goto again;

out:

	return copied ?: ret;

	return 0;

}



__printf(3, 0)

fs/bcachefs/thread_with_file.h

+2 −1
Original line number Diff line number Diff line
@@ -71,7 +71,8 @@ int bch2_run_thread_with_stdio(struct thread_with_stdio *, 
int bch2_run_thread_with_stdout(struct thread_with_stdio *,

				const struct thread_with_stdio_ops *);

int bch2_stdio_redirect_read(struct stdio_redirect *, char *, size_t);

int bch2_stdio_redirect_readline(struct stdio_redirect *, char *, size_t);



int bch2_stdio_redirect_readline(struct stdio_redirect *, darray_char *);



__printf(3, 0) ssize_t bch2_stdio_redirect_vprintf(struct stdio_redirect *, bool, const char *, va_list);

__printf(3, 4) ssize_t bch2_stdio_redirect_printf(struct stdio_redirect *, bool, const char *, ...);

fs/bcachefs/thread_with_file_types.h

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ struct stdio_buf { 
	spinlock_t		lock;

	wait_queue_head_t	wait;

	darray_char		buf;

	bool			waiting_for_line;

};



struct stdio_redirect {