This is a note to let you know that I've just added the patch titled
mtd: mtdconcat: Judge callback existence based on the master
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mtd-mtdconcat-judge-callback-existence-based-on-the-.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 22a4f4d865ee3153af15ae8c249f761c8a65ac21
Author: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
Date: Tue Aug 17 19:48:56 2021 +0800
mtd: mtdconcat: Judge callback existence based on the master
[ 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@xxxxxxxxxx>
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Link: https://lore.kernel.org/linux-mtd/20210817114857.2784825-2-chengzhihao1@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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);
