402-mtd-blktrans-call-add-disks-after-mtd-device.patch 3.1 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. @@ -386,19 +386,8 @@ int add_mtd_blktrans_dev(struct mtd_blkt
  26. if (new->readonly)
  27. set_disk_ro(gd, 1);
  28. - ret = device_add_disk(&new->mtd->dev, gd, NULL);
  29. - if (ret)
  30. - goto out_cleanup_disk;
  31. -
  32. - if (new->disk_attributes) {
  33. - ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
  34. - new->disk_attributes);
  35. - WARN_ON(ret);
  36. - }
  37. return 0;
  38. -out_cleanup_disk:
  39. - put_disk(new->disk);
  40. out_free_tag_set:
  41. blk_mq_free_tag_set(new->tag_set);
  42. out_kfree_tag_set:
  43. @@ -408,6 +397,35 @@ out_list_del:
  44. return ret;
  45. }
  46. +void register_mtd_blktrans_devs(void)
  47. +{
  48. + struct mtd_blktrans_ops *tr;
  49. + struct mtd_blktrans_dev *dev, *next;
  50. + int ret;
  51. +
  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))
  55. + continue;
  56. +
  57. + ret = device_add_disk(&dev->mtd->dev, dev->disk, NULL);
  58. + if (ret)
  59. + goto out_cleanup_disk;
  60. +
  61. + if (dev->disk_attributes) {
  62. + ret = sysfs_create_group(&disk_to_dev(dev->disk)->kobj,
  63. + dev->disk_attributes);
  64. + WARN_ON(ret);
  65. + }
  66. + }
  67. + }
  68. +
  69. + return;
  70. +
  71. +out_cleanup_disk:
  72. + put_disk(dev->disk);
  73. +}
  74. +
  75. int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
  76. {
  77. unsigned long flags;
  78. --- a/drivers/mtd/mtdcore.c
  79. +++ b/drivers/mtd/mtdcore.c
  80. @@ -32,6 +32,7 @@
  81. #include <linux/mtd/mtd.h>
  82. #include <linux/mtd/partitions.h>
  83. +#include <linux/mtd/blktrans.h>
  84. #include "mtdcore.h"
  85. @@ -1098,6 +1099,8 @@ int mtd_device_parse_register(struct mtd
  86. register_reboot_notifier(&mtd->reboot_notifier);
  87. }
  88. + register_mtd_blktrans_devs();
  89. +
  90. out:
  91. if (ret) {
  92. nvmem_unregister(mtd->otp_user_nvmem);
  93. --- a/include/linux/mtd/blktrans.h
  94. +++ b/include/linux/mtd/blktrans.h
  95. @@ -76,6 +76,7 @@ extern int deregister_mtd_blktrans(struc
  96. extern int add_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
  97. extern int del_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
  98. extern int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev);
  99. +extern void register_mtd_blktrans_devs(void);
  100. /**
  101. * module_mtd_blktrans() - Helper macro for registering a mtd blktrans driver