1 From 0bccc3722bdd88e8ae995e77ef9f7b77ee4cbdee Mon Sep 17 00:00:00 2001
2 From: Daniel Golle <daniel@makrotopia.org>
3 Date: Wed, 7 Apr 2021 22:45:54 +0100
4 Subject: [PATCH 2/2] mtd: blktrans: call add disks after mtd device
5 To: linux-mtd@lists.infradead.org
6 Cc: Vignesh Raghavendra <vigneshr@ti.com>,
7 Richard Weinberger <richard@nod.at>,
8 Miquel Raynal <miquel.raynal@bootlin.com>,
9 David Woodhouse <dwmw2@infradead.org>
11 Calling device_add_disk while holding mtd_table_mutex leads
12 to deadlock in case part_bits!=0 as block partition parsers
13 will try to open the newly created disks, trying to acquire
15 Move device_add_disk to additional function called after
16 add partitions of an MTD device have been added and locks
19 Signed-off-by: Daniel Golle <daniel@makrotopia.org>
21 drivers/mtd/mtd_blkdevs.c | 33 ++++++++++++++++++++++++++-------
22 drivers/mtd/mtdcore.c | 3 +++
23 include/linux/mtd/blktrans.h | 1 +
24 3 files changed, 30 insertions(+), 7 deletions(-)
26 --- a/drivers/mtd/mtd_blkdevs.c
27 +++ b/drivers/mtd/mtd_blkdevs.c
28 @@ -384,13 +384,6 @@ int add_mtd_blktrans_dev(struct mtd_blkt
32 - device_add_disk(&new->mtd->dev, gd, NULL);
34 - if (new->disk_attributes) {
35 - ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
36 - new->disk_attributes);
42 @@ -402,6 +395,27 @@ out_list_del:
46 +void register_mtd_blktrans_devs(void)
48 + struct mtd_blktrans_ops *tr;
49 + struct mtd_blktrans_dev *dev, *next;
52 + list_for_each_entry(tr, &blktrans_majors, list) {
53 + list_for_each_entry_safe(dev, next, &tr->devs, list) {
54 + if (disk_live(dev->disk))
57 + device_add_disk(&dev->mtd->dev, dev->disk, NULL);
58 + if (dev->disk_attributes) {
59 + ret = sysfs_create_group(&disk_to_dev(dev->disk)->kobj,
60 + dev->disk_attributes);
67 int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
70 --- a/drivers/mtd/mtdcore.c
71 +++ b/drivers/mtd/mtdcore.c
74 #include <linux/mtd/mtd.h>
75 #include <linux/mtd/partitions.h>
76 +#include <linux/mtd/blktrans.h>
80 @@ -1067,6 +1068,8 @@ int mtd_device_parse_register(struct mtd
82 ret = mtd_otp_nvmem_add(mtd);
84 + register_mtd_blktrans_devs();
87 if (ret && device_is_registered(&mtd->dev))
89 --- a/include/linux/mtd/blktrans.h
90 +++ b/include/linux/mtd/blktrans.h
91 @@ -76,6 +76,7 @@ extern int deregister_mtd_blktrans(struc
92 extern int add_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
93 extern int del_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
94 extern int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev);
95 +extern void register_mtd_blktrans_devs(void);
98 * module_mtd_blktrans() - Helper macro for registering a mtd blktrans driver