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 @@ -457,13 +457,6 @@ 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 @@ -475,6 +468,32 @@ error1:
46 +void register_mtd_blktrans_devs(struct mtd_info *mtd)
48 + struct mtd_blktrans_ops *tr;
49 + struct mtd_blktrans_dev *dev, *next;
50 + struct mtd_info *top_mtd;
53 + list_for_each_entry(tr, &blktrans_majors, list) {
54 + list_for_each_entry_safe(dev, next, &tr->devs, list) {
56 + while (top_mtd->parent)
57 + top_mtd = top_mtd->parent;
59 + if (mtd->index != top_mtd->index)
62 + device_add_disk(&dev->mtd->dev, dev->disk, NULL);
63 + if (dev->disk_attributes) {
64 + ret = sysfs_create_group(&disk_to_dev(dev->disk)->kobj,
65 + dev->disk_attributes);
72 int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
75 --- a/drivers/mtd/mtdcore.c
76 +++ b/drivers/mtd/mtdcore.c
79 #include <linux/mtd/mtd.h>
80 #include <linux/mtd/partitions.h>
81 +#include <linux/mtd/blktrans.h>
85 @@ -858,6 +859,8 @@ int mtd_device_parse_register(struct mtd
86 register_reboot_notifier(&mtd->reboot_notifier);
89 + register_mtd_blktrans_devs(mtd);
92 if (ret && device_is_registered(&mtd->dev))
94 --- a/include/linux/mtd/blktrans.h
95 +++ b/include/linux/mtd/blktrans.h
96 @@ -76,6 +76,7 @@ extern int deregister_mtd_blktrans(struc
97 extern int add_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
98 extern int del_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
99 extern int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev);
100 +extern void register_mtd_blktrans_devs(struct mtd_info *mtd);
103 #endif /* __MTD_TRANS_H__ */