From: Zhihao Cheng chengzhihao1@huawei.com
[ Upstream commit f9e109a209a8e01e16f37e1252304f1eb3908be4 ]
Since commit 46b5889cc2c5("mtd: implement proper partition handling") applied, mtd partition device won't hold some callback functions, such as _block_isbad, _block_markbad, etc. Besides, function mtd_block_isbad() will get mtd device's master mtd device, then invokes master mtd device's callback function. So, following process may result mtd_block_isbad() always return 0, even though mtd device has bad blocks:
1. Split a mtd device into 3 partitions: PA, PB, PC [ Each mtd partition device won't has callback function _block_isbad(). ] 2. Concatenate PA and PB as a new mtd device PN [ mtd_concat_create() finds out each subdev has no callback function _block_isbad(), so PN won't be assigned callback function concat_block_isbad(). ] Then, mtd_block_isbad() checks "!master->_block_isbad" is true, will always return 0.
Reproducer: // reproduce.c static int __init init_diy_module(void) { struct mtd_info *mtd[2]; struct mtd_info *mtd_combine = NULL;
mtd[0] = get_mtd_device_nm("NAND simulator partition 0"); if (!mtd[0]) { pr_err("cannot find mtd1\n"); return -EINVAL; } mtd[1] = get_mtd_device_nm("NAND simulator partition 1"); if (!mtd[1]) { pr_err("cannot find mtd2\n"); return -EINVAL; }
put_mtd_device(mtd[0]); put_mtd_device(mtd[1]);
mtd_combine = mtd_concat_create(mtd, 2, "Combine mtd"); if (mtd_combine == NULL) { pr_err("combine failed\n"); return -EINVAL; }
mtd_device_register(mtd_combine, NULL, 0); pr_info("Combine success\n");
return 0; }
1. ID="0x20,0xac,0x00,0x15" 2. modprobe nandsim id_bytes=$ID parts=50,100 badblocks=100 3. insmod reproduce.ko 4. flash_erase /dev/mtd3 0 0 libmtd: error!: MEMERASE64 ioctl failed for eraseblock 100 (mtd3) error 5 (Input/output error) // Should be "flash_erase: Skipping bad block at 00c80000"
Fixes: 46b5889cc2c54bac ("mtd: implement proper partition handling") Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Link: https://lore.kernel.org/linux-mtd/20210817114857.2784825-2-chengzhihao1@huaw... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mtd/mtdconcat.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c index 6e4d0017c0bd..af51eee6b5e8 100644 --- a/drivers/mtd/mtdconcat.c +++ b/drivers/mtd/mtdconcat.c @@ -641,6 +641,7 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c int i; size_t size; struct mtd_concat *concat; + struct mtd_info *subdev_master = NULL; uint32_t max_erasesize, curr_erasesize; int num_erase_region; int max_writebufsize = 0; @@ -679,17 +680,19 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c concat->mtd.subpage_sft = subdev[0]->subpage_sft; concat->mtd.oobsize = subdev[0]->oobsize; concat->mtd.oobavail = subdev[0]->oobavail; - if (subdev[0]->_writev) + + subdev_master = mtd_get_master(subdev[0]); + if (subdev_master->_writev) concat->mtd._writev = concat_writev; - if (subdev[0]->_read_oob) + if (subdev_master->_read_oob) concat->mtd._read_oob = concat_read_oob; - if (subdev[0]->_write_oob) + if (subdev_master->_write_oob) concat->mtd._write_oob = concat_write_oob; - if (subdev[0]->_block_isbad) + if (subdev_master->_block_isbad) concat->mtd._block_isbad = concat_block_isbad; - if (subdev[0]->_block_markbad) + if (subdev_master->_block_markbad) concat->mtd._block_markbad = concat_block_markbad; - if (subdev[0]->_panic_write) + if (subdev_master->_panic_write) concat->mtd._panic_write = concat_panic_write;
concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks; @@ -721,14 +724,22 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c subdev[i]->flags & MTD_WRITEABLE; }
+ subdev_master = mtd_get_master(subdev[i]); concat->mtd.size += subdev[i]->size; concat->mtd.ecc_stats.badblocks += subdev[i]->ecc_stats.badblocks; if (concat->mtd.writesize != subdev[i]->writesize || concat->mtd.subpage_sft != subdev[i]->subpage_sft || concat->mtd.oobsize != subdev[i]->oobsize || - !concat->mtd._read_oob != !subdev[i]->_read_oob || - !concat->mtd._write_oob != !subdev[i]->_write_oob) { + !concat->mtd._read_oob != !subdev_master->_read_oob || + !concat->mtd._write_oob != !subdev_master->_write_oob) { + /* + * Check against subdev[i] for data members, because + * subdev's attributes may be different from master + * mtd device. Check against subdev's master mtd + * device for callbacks, because the existence of + * subdev's callbacks is decided by master mtd device. + */ kfree(concat); printk("Incompatible OOB or ECC data on "%s"\n", subdev[i]->name);