1 files changed, 271 insertions, 120 deletions

diff --git a/fs/bcachefs/thread_with_file.c b/fs/bcachefs/thread_with_file.c
index 9220d7de10db..940db15d6a93 100644
--- a/fs/bcachefs/thread_with_file.c
+++ b/fs/bcachefs/thread_with_file.c
@@ -2,7 +2,6 @@
 #ifndef NO_BCACHEFS_FS
 
 #include "bcachefs.h"
-#include "printbuf.h"
 #include "thread_with_file.h"
 
 #include <linux/anon_inodes.h>
@@ -10,6 +9,7 @@
 #include <linux/kthread.h>
 #include <linux/pagemap.h>
 #include <linux/poll.h>
+#include <linux/sched/sysctl.h>
 
 void bch2_thread_with_file_exit(struct thread_with_file *thr)
 {
@@ -65,68 +65,82 @@ err:
 	return ret;
 }
 
-static inline bool thread_with_stdio_has_output(struct thread_with_stdio *thr)
+/* stdio_redirect */
+
+static bool stdio_redirect_has_input(struct stdio_redirect *stdio)
 {
-	return thr->stdio.output_buf.pos ||
-		thr->output2.nr ||
-		thr->thr.done;
+	return stdio->input.buf.nr || stdio->done;
 }
 
-static ssize_t thread_with_stdio_read(struct file *file, char __user *buf,
-				      size_t len, loff_t *ppos)
+static bool stdio_redirect_has_output(struct stdio_redirect *stdio)
 {
-	struct thread_with_stdio *thr =
-		container_of(file->private_data, struct thread_with_stdio, thr);
-	size_t copied = 0, b;
-	int ret = 0;
+	return stdio->output.buf.nr || stdio->done;
+}
 
-	if ((file->f_flags & O_NONBLOCK) &&
-	    !thread_with_stdio_has_output(thr))
-		return -EAGAIN;
+#define STDIO_REDIRECT_BUFSIZE		4096
 
-	ret = wait_event_interruptible(thr->stdio.output_wait,
-		thread_with_stdio_has_output(thr));
-	if (ret)
-		return ret;
+static bool stdio_redirect_has_input_space(struct stdio_redirect *stdio)
+{
+	return stdio->input.buf.nr < STDIO_REDIRECT_BUFSIZE || stdio->done;
+}
 
-	if (thr->thr.done)
-		return 0;
+static bool stdio_redirect_has_output_space(struct stdio_redirect *stdio)
+{
+	return stdio->output.buf.nr < STDIO_REDIRECT_BUFSIZE || stdio->done;
+}
 
-	while (len) {
-		ret = darray_make_room(&thr->output2, thr->stdio.output_buf.pos);
-		if (ret)
-			break;
+static void stdio_buf_init(struct stdio_buf *buf)
+{
+	spin_lock_init(&buf->lock);
+	init_waitqueue_head(&buf->wait);
+	darray_init(&buf->buf);
+}
 
-		spin_lock_irq(&thr->stdio.output_lock);
-		b = min_t(size_t, darray_room(thr->output2), thr->stdio.output_buf.pos);
+/* thread_with_stdio */
 
-		memcpy(&darray_top(thr->output2), thr->stdio.output_buf.buf, b);
-		memmove(thr->stdio.output_buf.buf,
-			thr->stdio.output_buf.buf + b,
-			thr->stdio.output_buf.pos - b);
+static void thread_with_stdio_done(struct thread_with_stdio *thr)
+{
+	thr->thr.done = true;
+	thr->stdio.done = true;
+	wake_up(&thr->stdio.input.wait);
+	wake_up(&thr->stdio.output.wait);
+}
 
-		thr->output2.nr += b;
-		thr->stdio.output_buf.pos -= b;
-		spin_unlock_irq(&thr->stdio.output_lock);
+static ssize_t thread_with_stdio_read(struct file *file, char __user *ubuf,
+				      size_t len, loff_t *ppos)
+{
+	struct thread_with_stdio *thr =
+		container_of(file->private_data, struct thread_with_stdio, thr);
+	struct stdio_buf *buf = &thr->stdio.output;
+	size_t copied = 0, b;
+	int ret = 0;
 
-		b = min(len, thr->output2.nr);
-		if (!b)
-			break;
+	if (!(file->f_flags & O_NONBLOCK)) {
+		ret = wait_event_interruptible(buf->wait, stdio_redirect_has_output(&thr->stdio));
+		if (ret)
+			return ret;
+	} else if (!stdio_redirect_has_output(&thr->stdio))
+		return -EAGAIN;
 
-		b -= copy_to_user(buf, thr->output2.data, b);
-		if (!b) {
+	while (len && buf->buf.nr) {
+		if (fault_in_writeable(ubuf, len) == len) {
 			ret = -EFAULT;
 			break;
 		}
 
-		copied	+= b;
-		buf	+= b;
-		len	-= b;
-
-		memmove(thr->output2.data,
-			thr->output2.data + b,
-			thr->output2.nr - b);
-		thr->output2.nr -= b;
+		spin_lock_irq(&buf->lock);
+		b = min_t(size_t, len, buf->buf.nr);
+
+		if (b && !copy_to_user_nofault(ubuf, buf->buf.data, b)) {
+			ubuf	+= b;
+			len	-= b;
+			copied	+= b;
+			buf->buf.nr -= b;
+			memmove(buf->buf.data,
+				buf->buf.data + b,
+				buf->buf.nr);
+		}
+		spin_unlock_irq(&buf->lock);
 	}
 
 	return copied ?: ret;
@@ -137,27 +151,20 @@ static int thread_with_stdio_release(struct inode *inode, struct file *file)
 	struct thread_with_stdio *thr =
 		container_of(file->private_data, struct thread_with_stdio, thr);
 
+	thread_with_stdio_done(thr);
 	bch2_thread_with_file_exit(&thr->thr);
-	printbuf_exit(&thr->stdio.input_buf);
-	printbuf_exit(&thr->stdio.output_buf);
-	darray_exit(&thr->output2);
-	thr->exit(thr);
+	darray_exit(&thr->stdio.input.buf);
+	darray_exit(&thr->stdio.output.buf);
+	thr->ops->exit(thr);
 	return 0;
 }
 
-#define WRITE_BUFFER		4096
-
-static inline bool thread_with_stdio_has_input_space(struct thread_with_stdio *thr)
-{
-	return thr->stdio.input_buf.pos < WRITE_BUFFER || thr->thr.done;
-}
-
 static ssize_t thread_with_stdio_write(struct file *file, const char __user *ubuf,
 				       size_t len, loff_t *ppos)
 {
 	struct thread_with_stdio *thr =
 		container_of(file->private_data, struct thread_with_stdio, thr);
-	struct printbuf *buf = &thr->stdio.input_buf;
+	struct stdio_buf *buf = &thr->stdio.input;
 	size_t copied = 0;
 	ssize_t ret = 0;
 
@@ -173,29 +180,30 @@ static ssize_t thread_with_stdio_write(struct file *file, const char __user *ubu
 			break;
 		}
 
-		spin_lock(&thr->stdio.input_lock);
-		if (buf->pos < WRITE_BUFFER)
-			bch2_printbuf_make_room(buf, min(b, WRITE_BUFFER - buf->pos));
-		b = min(len, printbuf_remaining_size(buf));
-
-		if (b && !copy_from_user_nofault(&buf->buf[buf->pos], ubuf, b)) {
-			ubuf += b;
-			len -= b;
-			copied += b;
-			buf->pos += b;
+		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);
+		b = min(len, darray_room(buf->buf));
+
+		if (b && !copy_from_user_nofault(&darray_top(buf->buf), ubuf, b)) {
+			buf->buf.nr += b;
+			ubuf	+= b;
+			len	-= b;
+			copied	+= b;
 		}
-		spin_unlock(&thr->stdio.input_lock);
+		spin_unlock(&buf->lock);
 
 		if (b) {
-			wake_up(&thr->stdio.input_wait);
+			wake_up(&buf->wait);
 		} else {
 			if ((file->f_flags & O_NONBLOCK)) {
 				ret = -EAGAIN;
 				break;
 			}
 
-			ret = wait_event_interruptible(thr->stdio.input_wait,
-					thread_with_stdio_has_input_space(thr));
+			ret = wait_event_interruptible(buf->wait,
+					stdio_redirect_has_input_space(&thr->stdio));
 			if (ret)
 				break;
 		}
@@ -209,90 +217,233 @@ static __poll_t thread_with_stdio_poll(struct file *file, struct poll_table_stru
 	struct thread_with_stdio *thr =
 		container_of(file->private_data, struct thread_with_stdio, thr);
 
-	poll_wait(file, &thr->stdio.output_wait, wait);
-	poll_wait(file, &thr->stdio.input_wait, wait);
+	poll_wait(file, &thr->stdio.output.wait, wait);
+	poll_wait(file, &thr->stdio.input.wait, wait);
 
 	__poll_t mask = 0;
 
-	if (thread_with_stdio_has_output(thr))
+	if (stdio_redirect_has_output(&thr->stdio))
 		mask |= EPOLLIN;
-	if (thread_with_stdio_has_input_space(thr))
+	if (stdio_redirect_has_input_space(&thr->stdio))
 		mask |= EPOLLOUT;
 	if (thr->thr.done)
 		mask |= EPOLLHUP|EPOLLERR;
 	return mask;
 }
 
+static __poll_t thread_with_stdout_poll(struct file *file, struct poll_table_struct *wait)
+{
+	struct thread_with_stdio *thr =
+		container_of(file->private_data, struct thread_with_stdio, thr);
+
+	poll_wait(file, &thr->stdio.output.wait, wait);
+
+	__poll_t mask = 0;
+
+	if (stdio_redirect_has_output(&thr->stdio))
+		mask |= EPOLLIN;
+	if (thr->thr.done)
+		mask |= EPOLLHUP|EPOLLERR;
+	return mask;
+}
+
+static int thread_with_stdio_flush(struct file *file, fl_owner_t id)
+{
+	struct thread_with_stdio *thr =
+		container_of(file->private_data, struct thread_with_stdio, thr);
+
+	return thr->thr.ret;
+}
+
+static long thread_with_stdio_ioctl(struct file *file, unsigned int cmd, unsigned long p)
+{
+	struct thread_with_stdio *thr =
+		container_of(file->private_data, struct thread_with_stdio, thr);
+
+	if (thr->ops->unlocked_ioctl)
+		return thr->ops->unlocked_ioctl(thr, cmd, p);
+	return -ENOTTY;
+}
+
 static const struct file_operations thread_with_stdio_fops = {
-	.release	= thread_with_stdio_release,
+	.llseek		= no_llseek,
 	.read		= thread_with_stdio_read,
 	.write		= thread_with_stdio_write,
 	.poll		= thread_with_stdio_poll,
+	.flush		= thread_with_stdio_flush,
+	.release	= thread_with_stdio_release,
+	.unlocked_ioctl	= thread_with_stdio_ioctl,
+};
+
+static const struct file_operations thread_with_stdout_fops = {
 	.llseek		= no_llseek,
+	.read		= thread_with_stdio_read,
+	.poll		= thread_with_stdout_poll,
+	.flush		= thread_with_stdio_flush,
+	.release	= thread_with_stdio_release,
+	.unlocked_ioctl	= thread_with_stdio_ioctl,
 };
 
+static int thread_with_stdio_fn(void *arg)
+{
+	struct thread_with_stdio *thr = arg;
+
+	thr->thr.ret = thr->ops->fn(thr);
+
+	thread_with_stdio_done(thr);
+	return 0;
+}
+
 int bch2_run_thread_with_stdio(struct thread_with_stdio *thr,
-			       void (*exit)(struct thread_with_stdio *),
-			       int (*fn)(void *))
+			       const struct thread_with_stdio_ops *ops)
 {
-	thr->stdio.input_buf = PRINTBUF;
-	thr->stdio.input_buf.atomic++;
-	spin_lock_init(&thr->stdio.input_lock);
-	init_waitqueue_head(&thr->stdio.input_wait);
+	stdio_buf_init(&thr->stdio.input);
+	stdio_buf_init(&thr->stdio.output);
+	thr->ops = ops;
 
-	thr->stdio.output_buf = PRINTBUF;
-	thr->stdio.output_buf.atomic++;
-	spin_lock_init(&thr->stdio.output_lock);
-	init_waitqueue_head(&thr->stdio.output_wait);
+	return bch2_run_thread_with_file(&thr->thr, &thread_with_stdio_fops, thread_with_stdio_fn);
+}
 
-	darray_init(&thr->output2);
-	thr->exit = exit;
+int bch2_run_thread_with_stdout(struct thread_with_stdio *thr,
+				const struct thread_with_stdio_ops *ops)
+{
+	stdio_buf_init(&thr->stdio.input);
+	stdio_buf_init(&thr->stdio.output);
+	thr->ops = ops;
 
-	return bch2_run_thread_with_file(&thr->thr, &thread_with_stdio_fops, fn);
+	return bch2_run_thread_with_file(&thr->thr, &thread_with_stdout_fops, thread_with_stdio_fn);
 }
+EXPORT_SYMBOL_GPL(bch2_run_thread_with_stdout);
 
-int bch2_stdio_redirect_read(struct stdio_redirect *stdio, char *buf, size_t len)
+int bch2_stdio_redirect_read(struct stdio_redirect *stdio, char *ubuf, size_t len)
 {
-	wait_event(stdio->input_wait,
-		   stdio->input_buf.pos || stdio->done);
+	struct stdio_buf *buf = &stdio->input;
+
+	/*
+	 * we're waiting on user input (or for the file descriptor to be
+	 * closed), don't want a hung task warning:
+	 */
+	do {
+		wait_event_timeout(buf->wait, stdio_redirect_has_input(stdio),
+				   sysctl_hung_task_timeout_secs * HZ / 2);
+	} while (!stdio_redirect_has_input(stdio));
 
 	if (stdio->done)
 		return -1;
 
-	spin_lock(&stdio->input_lock);
-	int ret = min(len, stdio->input_buf.pos);
-	stdio->input_buf.pos -= ret;
-	memcpy(buf, stdio->input_buf.buf, ret);
-	memmove(stdio->input_buf.buf,
-		stdio->input_buf.buf + ret,
-		stdio->input_buf.pos);
-	spin_unlock(&stdio->input_lock);
+	spin_lock(&buf->lock);
+	int ret = min(len, buf->buf.nr);
+	buf->buf.nr -= ret;
+	memcpy(ubuf, buf->buf.data, ret);
+	memmove(buf->buf.data,
+		buf->buf.data + ret,
+		buf->buf.nr);
+	spin_unlock(&buf->lock);
 
-	wake_up(&stdio->input_wait);
+	wake_up(&buf->wait);
 	return ret;
 }
 
-int bch2_stdio_redirect_readline(struct stdio_redirect *stdio, char *buf, size_t len)
+int bch2_stdio_redirect_readline(struct stdio_redirect *stdio, char *ubuf, size_t len)
 {
-	wait_event(stdio->input_wait,
-		   stdio->input_buf.pos || stdio->done);
-
-	if (stdio->done)
-		return -1;
+	struct stdio_buf *buf = &stdio->input;
+	size_t copied = 0;
+	ssize_t ret = 0;
+again:
+	do {
+		wait_event_timeout(buf->wait, stdio_redirect_has_input(stdio),
+				   sysctl_hung_task_timeout_secs * HZ / 2);
+	} while (!stdio_redirect_has_input(stdio));
+
+	if (stdio->done) {
+		ret = -1;
+		goto out;
+	}
 
-	spin_lock(&stdio->input_lock);
-	int ret = min(len, stdio->input_buf.pos);
-	char *n = memchr(stdio->input_buf.buf, '\n', ret);
+	spin_lock(&buf->lock);
+	size_t b = min(len, buf->buf.nr);
+	char *n = memchr(buf->buf.data, '\n', b);
 	if (n)
-		ret = min(ret, n + 1 - stdio->input_buf.buf);
-	stdio->input_buf.pos -= ret;
-	memcpy(buf, stdio->input_buf.buf, ret);
-	memmove(stdio->input_buf.buf,
-		stdio->input_buf.buf + ret,
-		stdio->input_buf.pos);
-	spin_unlock(&stdio->input_lock);
-
-	wake_up(&stdio->input_wait);
+		b = min_t(size_t, b, n + 1 - buf->buf.data);
+	buf->buf.nr -= b;
+	memcpy(ubuf, buf->buf.data, b);
+	memmove(buf->buf.data,
+		buf->buf.data + b,
+		buf->buf.nr);
+	ubuf += b;
+	len -= b;
+	copied += b;
+	spin_unlock(&buf->lock);
+
+	wake_up(&buf->wait);
+
+	if (!n && len)
+		goto again;
+out:
+	return copied ?: ret;
+}
+
+__printf(3, 0)
+static ssize_t bch2_darray_vprintf(darray_char *out, gfp_t gfp, const char *fmt, va_list args)
+{
+	ssize_t ret;
+
+	do {
+		va_list args2;
+		size_t len;
+
+		va_copy(args2, args);
+		len = vsnprintf(out->data + out->nr, darray_room(*out), fmt, args2);
+		va_end(args2);
+
+		if (len + 1 <= darray_room(*out)) {
+			out->nr += len;
+			return len;
+		}
+
+		ret = darray_make_room_gfp(out, len + 1, gfp);
+	} while (ret == 0);
+
+	return ret;
+}
+
+ssize_t bch2_stdio_redirect_vprintf(struct stdio_redirect *stdio, bool nonblocking,
+				    const char *fmt, va_list args)
+{
+	struct stdio_buf *buf = &stdio->output;
+	unsigned long flags;
+	ssize_t ret;
+
+again:
+	spin_lock_irqsave(&buf->lock, flags);
+	ret = bch2_darray_vprintf(&buf->buf, GFP_NOWAIT, fmt, args);
+	spin_unlock_irqrestore(&buf->lock, flags);
+
+	if (ret < 0) {
+		if (nonblocking)
+			return -EAGAIN;
+
+		ret = wait_event_interruptible(buf->wait,
+				stdio_redirect_has_output_space(stdio));
+		if (ret)
+			return ret;
+		goto again;
+	}
+
+	wake_up(&buf->wait);
+	return ret;
+}
+
+ssize_t bch2_stdio_redirect_printf(struct stdio_redirect *stdio, bool nonblocking,
+				const char *fmt, ...)
+{
+	va_list args;
+	ssize_t ret;
+
+	va_start(args, fmt);
+	ret = bch2_stdio_redirect_vprintf(stdio, nonblocking, fmt, args);
+	va_end(args);
+
 	return ret;
 }