Commit e6e620f0 authored Jan 22, 2018 by Boris Brezillon Committed by Boris Brezillon Feb 12, 2018

mtd: Make sure the device supports erase operations in mtd_erase()

Some devices do not implement ->_erase() or have an invalid ->erasesize
value. In this case, mtd_erase() should return -ENOTSUPP.

Note that the test is not done on the MTD_NO_ERASE flag because this
flag means 'erasing a block before writing to it is unnecessary',
not 'the erase operation is not supported'. Actually, some drivers are
setting the MTD_NO_ERASE flag but still implementing the ->_erase()
hook and setting a valid ->erasesize value.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

parent 7928b2cb

drivers/mtd/mtdcore.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -971,10 +971,14 @@ EXPORT_SYMBOL_GPL(__put_mtd_device);
		*/
		int mtd_erase(struct mtd_info mtd, struct erase_info instr)
		{
		if (!mtd->erasesize \|\| !mtd->_erase)
		return -ENOTSUPP;

		if (instr->addr >= mtd->size \|\| instr->len > mtd->size - instr->addr)
		return -EINVAL;
		if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;

		instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
		if (!instr->len) {
		instr->state = MTD_ERASE_DONE;