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/zfs#4104. The function is tiny enough that my patch could qualify to be called a "rewrite", so I am just copying the function on the basis that a rewrite allows me to license the code under both the CDDL and GPL. Signed-off-by: Richard Yao <[email protected]>
ryao · Dec 15, 2015 · ab142af · ab142af
1 parent e0ed96f
commit ab142af
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Showing 2 changed files with 9 additions and 4 deletions.
diff --git a/include/sys/kobj.h b/include/sys/kobj.h
@@ -36,7 +36,7 @@ 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);
+			  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, (vnode_t *)file->_fd, 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);