402-mtd-blktrans-call-add-disks-after-mtd-device.patch 3.0 KB

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  1. From 0bccc3722bdd88e8ae995e77ef9f7b77ee4cbdee Mon Sep 17 00:00:00 2001
  2. From: Daniel Golle <[email protected]>
  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: [email protected]
  6. Cc: Vignesh Raghavendra <[email protected]>,
  7. Richard Weinberger <[email protected]>,
  8. Miquel Raynal <[email protected]>,
  9. David Woodhouse <[email protected]>
  10. Calling device_add_disk while holding mtd_table_mutex leads
  11. to deadlock in case part_bits!=0 as block partition parsers
  12. will try to open the newly created disks, trying to acquire
  13. mutex once again.
  14. Move device_add_disk to additional function called after
  15. add partitions of an MTD device have been added and locks
  16. have been released.
  17. Signed-off-by: Daniel Golle <[email protected]>
  18. ---
  19. drivers/mtd/mtd_blkdevs.c | 33 ++++++++++++++++++++++++++-------
  20. drivers/mtd/mtdcore.c | 3 +++
  21. include/linux/mtd/blktrans.h | 1 +
  22. 3 files changed, 30 insertions(+), 7 deletions(-)
  23. --- a/drivers/mtd/mtd_blkdevs.c
  24. +++ b/drivers/mtd/mtd_blkdevs.c
  25. @@ -457,13 +457,6 @@ int add_mtd_blktrans_dev(struct mtd_blkt
  26. if (new->readonly)
  27. set_disk_ro(gd, 1);
  28. - device_add_disk(&new->mtd->dev, gd, NULL);
  29. -
  30. - if (new->disk_attributes) {
  31. - ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
  32. - new->disk_attributes);
  33. - WARN_ON(ret);
  34. - }
  35. return 0;
  36. error4:
  37. kfree(new->tag_set);
  38. @@ -475,6 +468,32 @@ error1:
  39. return ret;
  40. }
  41. +void register_mtd_blktrans_devs(struct mtd_info *mtd)
  42. +{
  43. + struct mtd_blktrans_ops *tr;
  44. + struct mtd_blktrans_dev *dev, *next;
  45. + struct mtd_info *top_mtd;
  46. + int ret;
  47. +
  48. + list_for_each_entry(tr, &blktrans_majors, list) {
  49. + list_for_each_entry_safe(dev, next, &tr->devs, list) {
  50. + top_mtd = dev->mtd;
  51. + while (top_mtd->parent)
  52. + top_mtd = top_mtd->parent;
  53. +
  54. + if (mtd->index != top_mtd->index)
  55. + continue;
  56. +
  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);
  61. + WARN_ON(ret);
  62. + }
  63. + }
  64. + }
  65. +}
  66. +
  67. int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
  68. {
  69. unsigned long flags;
  70. --- a/drivers/mtd/mtdcore.c
  71. +++ b/drivers/mtd/mtdcore.c
  72. @@ -32,6 +32,7 @@
  73. #include <linux/mtd/mtd.h>
  74. #include <linux/mtd/partitions.h>
  75. +#include <linux/mtd/blktrans.h>
  76. #include "mtdcore.h"
  77. @@ -858,6 +859,8 @@ int mtd_device_parse_register(struct mtd
  78. register_reboot_notifier(&mtd->reboot_notifier);
  79. }
  80. + register_mtd_blktrans_devs(mtd);
  81. +
  82. out:
  83. if (ret && device_is_registered(&mtd->dev))
  84. del_mtd_device(mtd);
  85. --- a/include/linux/mtd/blktrans.h
  86. +++ b/include/linux/mtd/blktrans.h
  87. @@ -76,6 +76,7 @@ extern int deregister_mtd_blktrans(struc
  88. extern int add_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
  89. extern int del_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
  90. extern int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev);
  91. +extern void register_mtd_blktrans_devs(struct mtd_info *mtd);
  92. #endif /* __MTD_TRANS_H__ */