mtd: Add WARN_ON_ONCE() to mtd_read() to check the return value

ZhaoLong Wang · miquelraynal · commit 0339f62a9a77 · 2023-10-16T10:50:28.000+02:00
If the driver cannot read all the requested data, -EBADMSG or -EUCLEAN should never be returned. Add a WARN_ON_ONCE() to help driver developers detect this error. Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20230926065733.3240322-1-wangzhaolong1@huawei.com
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
@@ -1505,6 +1505,8 @@ int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
 	ret = mtd_read_oob(mtd, from, &ops);
 	*retlen = ops.retlen;
 
+	WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret));
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(mtd_read);

Original file line number	Diff line number	Diff line change
`@@ -1505,6 +1505,8 @@ int mtd_read(struct mtd_info mtd, loff_t from, size_t len, size_t retlen,`
`1505`	`1505`	`ret = mtd_read_oob(mtd, from, &ops);`
`1506`	`1506`	`*retlen = ops.retlen;`
`1507`	`1507`
	`1508`	`+ WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret));`
	`1509`	`+`
`1508`	`1510`	`return ret;`
`1509`	`1511`	`}`
`1510`	`1512`	`EXPORT_SYMBOL_GPL(mtd_read);`