Replace sbuf_overflowed() with sbuf_error(), which returns any error

code associated with overflow or with the drain function.  While this
function is not expected to be used often, it produces more information
in the form of an errno that sbuf_overflowed() did.

1 files changed, 25 insertions, 28 deletions

diff --git a/sys/kern/subr_sbuf.c b/sys/kern/subr_sbuf.c
index 58964fb..4535337 100644
--- a/sys/kern/subr_sbuf.c
+++ b/sys/kern/subr_sbuf.c
@@ -66,7 +66,6 @@ static MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers");
 #define	SBUF_ISDYNAMIC(s)	((s)->s_flags & SBUF_DYNAMIC)
 #define	SBUF_ISDYNSTRUCT(s)	((s)->s_flags & SBUF_DYNSTRUCT)
 #define	SBUF_ISFINISHED(s)	((s)->s_flags & SBUF_FINISHED)
-#define	SBUF_HASOVERFLOWED(s)	((s)->s_flags & SBUF_OVERFLOWED)
 #define	SBUF_HASROOM(s)		((s)->s_len < (s)->s_size - 1)
 #define	SBUF_FREESPACE(s)	((s)->s_size - (s)->s_len - 1)
 #define	SBUF_CANEXTEND(s)	((s)->s_flags & SBUF_AUTOEXTEND)
@@ -247,7 +246,6 @@ sbuf_clear(struct sbuf *s)
 	/* don't care if it's finished or not */
 
 	SBUF_CLEARFLAG(s, SBUF_FINISHED);
-	SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
 	s->s_error = 0;
 	s->s_len = 0;
 }
@@ -299,10 +297,10 @@ sbuf_drain(struct sbuf *s)
 	int len;
 
 	KASSERT(s->s_len > 0, ("Shouldn't drain empty sbuf %p", s));
+	KASSERT(s->s_error == 0, ("Called %s with error on %p", __func__, s));
 	len = s->s_drain_func(s->s_drain_arg, s->s_buf, s->s_len);
 	if (len < 0) {
 		s->s_error = -len;
-		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
 		return (s->s_error);
 	}
 	KASSERT(len > 0 && len <= s->s_len,
@@ -334,7 +332,7 @@ sbuf_put_byte(int c, struct sbuf *s)
 	assert_sbuf_integrity(s);
 	assert_sbuf_state(s, 0);
 
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return;
 	if (SBUF_FREESPACE(s) <= 0) {
 		/* 
@@ -344,8 +342,8 @@ sbuf_put_byte(int c, struct sbuf *s)
 		if (s->s_drain_func != NULL)
 			(void)sbuf_drain(s);
 		else if (sbuf_extend(s, 1) < 0)
-			SBUF_SETFLAG(s, SBUF_OVERFLOWED);
-		if (SBUF_HASOVERFLOWED(s))
+			s->s_error = ENOMEM;
+		if (s->s_error != 0)
 			return;
 	}
 	s->s_buf[s->s_len++] = c;
@@ -375,11 +373,11 @@ sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
 	assert_sbuf_integrity(s);
 	assert_sbuf_state(s, 0);
 
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 	for (; str < end; str++) {
 		sbuf_put_byte(*str, s);
-		if (SBUF_HASOVERFLOWED(s))
+		if (s->s_error != 0)
 			return (-1);
  	}
 	return (0);
@@ -398,7 +396,7 @@ sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
 	KASSERT(s->s_drain_func == NULL,
 	    ("Nonsensical copyin to sbuf %p with a drain", s));
 
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 	if (len == 0)
 		return (0);
@@ -439,12 +437,12 @@ sbuf_cat(struct sbuf *s, const char *str)
 	assert_sbuf_integrity(s);
 	assert_sbuf_state(s, 0);
 
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 
 	while (*str != '\0') {
 		sbuf_put_byte(*str, s);
-		if (SBUF_HASOVERFLOWED(s))
+		if (s->s_error != 0)
 			return (-1);
 	}
 	return (0);
@@ -464,7 +462,7 @@ sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
 	KASSERT(s->s_drain_func == NULL,
 	    ("Nonsensical copyin to sbuf %p with a drain", s));
 
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 
 	if (len == 0)
@@ -476,7 +474,7 @@ sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
 	}
 	switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
 	case ENAMETOOLONG:
-		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
+		s->s_error = ENOMEM;
 		/* fall through */
 	case 0:
 		s->s_len += done - 1;
@@ -518,7 +516,7 @@ sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
 	    ("%s called with a NULL format string", __func__));
 
 	(void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 	return (0);
 }
@@ -535,7 +533,7 @@ sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
 	KASSERT(fmt != NULL,
 	    ("%s called with a NULL format string", __func__));
 
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 
 	/*
@@ -578,12 +576,12 @@ sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
 		len = SBUF_FREESPACE(s);
 	s->s_len += len;
 	if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
-		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
+		s->s_error = ENOMEM;
 
 	KASSERT(s->s_len < s->s_size,
 	    ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
 
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 	return (0);
 }
@@ -612,7 +610,7 @@ sbuf_putc(struct sbuf *s, int c)
 {
 
 	sbuf_putc_func(c, s);
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 	return (0);
 }
@@ -629,7 +627,7 @@ sbuf_trim(struct sbuf *s)
 	KASSERT(s->s_drain_func == NULL,
 	    ("%s makes no sense on sbuf %p with drain", __func__, s));
 
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 
 	while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1]))
@@ -639,13 +637,13 @@ sbuf_trim(struct sbuf *s)
 }
 
 /*
- * Check if an sbuf overflowed
+ * Check if an sbuf has an error.
  */
 int
-sbuf_overflowed(struct sbuf *s)
+sbuf_error(struct sbuf *s)
 {
 
-	return (SBUF_HASOVERFLOWED(s));
+	return (s->s_error);
 }
 
 /*
@@ -654,19 +652,18 @@ sbuf_overflowed(struct sbuf *s)
 int
 sbuf_finish(struct sbuf *s)
 {
-	int error = 0;
+	int error;
 
 	assert_sbuf_integrity(s);
 	assert_sbuf_state(s, 0);
 
+	error = s->s_error;
 	if (s->s_drain_func != NULL) {
-		error = s->s_error;
 		while (s->s_len > 0 && error == 0)
 			error = sbuf_drain(s);
-	} else if (SBUF_HASOVERFLOWED(s))
-		error = ENOMEM;
+	}
 	s->s_buf[s->s_len] = '\0';
-	SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
+	s->s_error = 0;
 	SBUF_SETFLAG(s, SBUF_FINISHED);
 #ifdef _KERNEL
 	return (error);
@@ -703,7 +700,7 @@ sbuf_len(struct sbuf *s)
 	KASSERT(s->s_drain_func == NULL,
 	    ("%s makes no sense on sbuf %p with drain", __func__, s));
 
-	if (SBUF_HASOVERFLOWED(s))
+	if (s->s_error != 0)
 		return (-1);
 	return (s->s_len);
 }