buffer: better stdio copyin panic message

jeffpc · jeffpc · commit 3da89fe30747 · 2018-10-11T14:26:12.000-04:00
It makes sense to include the reason for the error in the panic message.

Signed-off-by: Josef 'Jeff' Sipek &lt;jeffpc@josefsipek.net&gt;
diff --git a/buffer_stdio.c b/buffer_stdio.c
@@ -41,7 +41,8 @@ static void stdio_buffer_copyin(struct buffer *buffer, size_t off,
 				const void *newdata, size_t newdatalen)
 {
 	if (fwrite(newdata, newdatalen, 1, buffer->private) != 1)
-		panic("%s: failed to write data to buffer", __func__);
+		panic("%s: failed to write data to buffer: %s", __func__,
+		      strerror(errno));
 }
 
 const struct buffer_ops stdio_buffer = {

Original file line number	Diff line number	Diff line change
`@@ -41,7 +41,8 @@ static void stdio_buffer_copyin(struct buffer *buffer, size_t off,`
`41`	`41`	`const void *newdata, size_t newdatalen)`
`42`	`42`	`{`
`43`	`43`	`if (fwrite(newdata, newdatalen, 1, buffer->private) != 1)`
`44`		`- panic("%s: failed to write data to buffer", __func__);`
	`44`	`+ panic("%s: failed to write data to buffer: %s", __func__,`
	`45`	`+ strerror(errno));`
`45`	`46`	`}`
`46`	`47`
`47`	`48`	`const struct buffer_ops stdio_buffer = {`