9os

commit acce5499735e62c93f8383df281037b16f76b753
parent 1c4f3ff0aa165ed13b3706047dc001447f274f39
Author: Roberto Vargas <roberto.vargas@arm.com>
Date:   Tue,  5 Mar 2019 12:27:25 +0000

[dev] Add devseek()

This function is like seek() but it acts over channels
instead of file descriptors.

Change-Id: I25463f460e6df3d1a6dc1015d239de3556da877f

Diffstat:
M
drivers/dev.c
 | 
28
+++++++++++++++++-----------
M
drivers/dev.h
 | 
3
+++

2 files changed, 20 insertions(+), 11 deletions(-)
diff --git a/drivers/dev.c b/drivers/dev.c
@@ -380,18 +380,8 @@ devwrite(Chan *c, void *buf, int n)
 }
 
 int
-seek(int fd, long long off, int whence)
+devseek(Chan *c, long long off, int whence)
 {
-	Chan *c;
-
-	if ((c = fd2chan(fd)) == NULL)
-		return -1;
-
-	if (c->qid & CHDIR) {
-		errno = EISDIR;
-		return -1;
-	}
-
 	switch (whence) {
 	case 0:
 		c->offset = off;
@@ -408,6 +398,22 @@ seek(int fd, long long off, int whence)
 }
 
 int
+seek(int fd, long long off, int whence)
+{
+	Chan *c;
+
+	if ((c = fd2chan(fd)) == NULL)
+		return -1;
+
+	if (c->qid & CHDIR) {
+		errno = EISDIR;
+		return -1;
+	}
+
+	return devseek(c, off,whence);
+}
+
+int
 bind(char *new, char *where)
 {
 	int i;
diff --git a/drivers/dev.h b/drivers/dev.h
@@ -41,6 +41,9 @@ struct attr {
 	char *value;
 };
 
+
+extern int devseek(Chan *c, long long off, int whence);
+extern Chan * namec(const char *name, int mode);
 extern Chan *clone(Chan *c, Chan *nc);
 extern void chanclose(Chan *c);
 extern int buf2chan(Chan *c,