402-mtd-blktrans-call-add-disks-after-mtd-device.patch 2.8 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. @@ -384,13 +384,6 @@ 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. out_free_tag_set:
  37. @@ -402,6 +395,27 @@ out_list_del:
  38. return ret;
  39. }
  40. +void register_mtd_blktrans_devs(void)
  41. +{
  42. + struct mtd_blktrans_ops *tr;
  43. + struct mtd_blktrans_dev *dev, *next;
  44. + int ret;
  45. +
  46. + list_for_each_entry(tr, &blktrans_majors, list) {
  47. + list_for_each_entry_safe(dev, next, &tr->devs, list) {
  48. + if (disk_live(dev->disk))
  49. + continue;
  50. +
  51. + device_add_disk(&dev->mtd->dev, dev->disk, NULL);
  52. + if (dev->disk_attributes) {
  53. + ret = sysfs_create_group(&disk_to_dev(dev->disk)->kobj,
  54. + dev->disk_attributes);
  55. + WARN_ON(ret);
  56. + }
  57. + }
  58. + }
  59. +}
  60. +
  61. int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
  62. {
  63. unsigned long flags;
  64. --- a/drivers/mtd/mtdcore.c
  65. +++ b/drivers/mtd/mtdcore.c
  66. @@ -31,6 +31,7 @@
  67. #include <linux/mtd/mtd.h>
  68. #include <linux/mtd/partitions.h>
  69. +#include <linux/mtd/blktrans.h>
  70. #include "mtdcore.h"
  71. @@ -1002,6 +1003,8 @@ int mtd_device_parse_register(struct mtd
  72. ret = mtd_otp_nvmem_add(mtd);
  73. + register_mtd_blktrans_devs();
  74. +
  75. out:
  76. if (ret && device_is_registered(&mtd->dev))
  77. del_mtd_device(mtd);
  78. --- a/include/linux/mtd/blktrans.h
  79. +++ b/include/linux/mtd/blktrans.h
  80. @@ -76,6 +76,7 @@ extern int deregister_mtd_blktrans(struc
  81. extern int add_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
  82. extern int del_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
  83. extern int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev);
  84. +extern void register_mtd_blktrans_devs(void);
  85. /**
  86. * module_mtd_blktrans() - Helper macro for registering a mtd blktrans driver