Messages in this thread | | | From | Miquel Raynal <> | Subject | Re: [PATCH 1/2] mtd: mtdconcat: Judge callback function existence getting from master for each partition | Date | Mon, 16 Aug 2021 16:27:19 +0200 |
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On Sat, 2021-07-31 at 02:32:42 UTC, Zhihao Cheng wrote: > 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("comnoine fail\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>
Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/next, thanks.
Miquel
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