kobj_read_file: Return -1 on vn_rdwr() error

I noticed that the SPL implementation of kobj_read_file is not correct after comparing it with the userland implementation of kobj_read_file() in openzfs#4104. Note that we no longer pass RLIM64_INFINITY with this, but our vn_rdwr implementation did not support it anyway, so there is no difference. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes openzfs#513
behlendorf · Jan 23, 2016 · be29e6a · be29e6a
1 parent 7323da1
commit be29e6a
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Showing 2 changed files with 10 additions and 5 deletions.
diff --git a/include/sys/kobj.h b/include/sys/kobj.h
@@ -35,8 +35,8 @@ typedef struct _buf buf_t;
 
 extern struct _buf *kobj_open_file(const char *name);
 extern void kobj_close_file(struct _buf *file);
-extern int kobj_read_file(struct _buf *file, char *buf,
-			  ssize_t size, offset_t off);
+extern int kobj_read_file(struct _buf *file, char *buf, unsigned size,
+    unsigned off);
 extern int kobj_get_filesize(struct _buf *file, uint64_t *size);
 
 #endif /* SPL_KOBJ_H */
diff --git a/module/spl/spl-kobj.c b/module/spl/spl-kobj.c
@@ -57,10 +57,15 @@ kobj_close_file(struct _buf *file)
 EXPORT_SYMBOL(kobj_close_file);
 
 int
-kobj_read_file(struct _buf *file, char *buf, ssize_t size, offset_t off)
+kobj_read_file(struct _buf *file, char *buf, unsigned size, unsigned off)
 {
-	return (vn_rdwr(UIO_READ, file->vp, buf, size, off,
-	       UIO_SYSSPACE, 0, RLIM64_INFINITY, 0, NULL));
+	ssize_t resid;
+
+	if (vn_rdwr(UIO_READ, file->vp, buf, size, (offset_t)off,
+	    UIO_SYSSPACE, 0, 0, 0, &resid) != 0)
+		return (-1);
+
+	return (size - resid);
 } /* kobj_read_file() */
 EXPORT_SYMBOL(kobj_read_file);